A3-1U

JAij ('?

THE EFFECT OF MONETARY REWARD AND KNOWLEDGE OF RESULTS

ON COMPLEX-CHOICE REACTION TIMES

THESIS

Presented to the Graduate Council of the

North Texas State University in Partial

Fulfillment of the Requirements

For the Degree of

MASTER OF SCIENCE

By

Terry Barnett Davies, B. A.

Denton, Texas

May, 1975

Davies, Terry B., The Effect of Monetary Reward and

Knowledge of Results on Complex-Choice Reaction Times.

Master of Science (Experimental Psychology), May 1975, 63 pp.,

10 tables, 3 illustrations, 39 titles.

This investigation was designed to determine relative

effects of monetary reward and knowledge of results on

complex-choice reaction time tasks. Subjects were twenty-

five male and thirty-two female undergraduate students.

Apparatus consisted of nine stimulus lights and eight re-

sponse keys. Subjects were required to add the number of

lights presented, subtract the sum from a constant, and press

the correctly numbered response key. Reward subjects re-

ceived twenty-five cents for responses faster than a pre-

determined criterion, and twenty-five cents was deducted

for slower responses. Knowledge of results subjects were

told their reaction times after each trial. Results indi-

cated (1) no significant differences between any conditions,

(2) a significant overall practice effect (.01 level), and

(3) that males were significantly faster than females

(.01 level).

TABLE OF CONTENTS

PageLIST OF TABLES ....... . ............ iv

LIST OF ILLUSTRATIONS ................ v

Chapter

I. INTRODUCTION...... . ..........

General Purpose of StudyHistorical DevelopmentSurvey of LiteratureStatement of ProblemSpecific Purposes of StudyHypotheses

II. METHOD.*................................ 16

SubjectsApparatusExperimental ProcedureExperimental Design

III. RESULTS .. *................................26

Statistical AnalysisTenability of Hypotheses

IV. DISCUSSION OF RESULTS .................... 38

V. SUMMARY AND CONCLUSIONS .0. .. .. .. .... . 50

APPENDIX -*-.-.-.....-.-.-..... . . . . . . . . . . ... 53

BIBLIOGRAPHY................0.0 .... . . .. ......60

iii

LIST OF TABLES

Table Page

I. Stimulus Configurations and Foreperiods...... 21

II. Cut-Off Points in Seconds and Percentageof Projected "Faster" Responses .... . . ... 22

III. Means and Standard Deviations of ReactionTimes for all Conditions............... 27

IV. Summary of Analysis of Variance of the Sexx Motivation x Trial Design................29

V. Summary of Analysis of Variance of the Sexx Motivation x Block Design................32

VI. Means and Standard Deviations of Sex andTrial Block Reaction Times.............. 33

VII. Reward Subjects' Reaction Times on each Trial . . 53

VIII. Knowledge of Results Subjects' Reaction Timeson each Trial.-...-........ . . .......... 55

IX. Control Subjects' Reaction Times on each Trial . 57

X. Means and Standard Deviations of MotivationalCondition and Trial Block Reaction Times . . 59

iv

LIST OF ILLUSTRATIONS

Figure Page

1. Visual Choice Reaction Time Apparatus .......... 16

2. Male and Female Means as a Function ofMotivational Condition ..*............. 28

3. Practice Effect for Males and Females ..o........34

V

CHAPTER I

INTRODUCTION

General Purpose of Study

In general, the objective of the present study was to

incorporate the findings from two areas of psychological

research, reaction time studies and motivational studies, in

order to investigate the motivational effects of knowledge

of results and reward on a choice reaction time (CRT) task.

Historical Development

Among the first reaction time experiments were those

conducted by Helmholtz in 1850, when he attempted to measure

the conduction speed of human sensory nerves by electrical

stimulation. Helmholtz obtained an estimate of the rate of

nerve conduction, but his method was confounded by the

subject's reaction time in that the time measurement was

taken from the moment the stimulus touched the subject's

skin until he responded to the shock by moving his hand.

Helmholtz was, therefore, measuring reaction time, not just

nerve conduction (29). In 1868 Donders attempted to measure

the time of mental processes by requiring subjects to make

an intervening discrimination or choice between the stimulus

and the response. Then, by subtracting the simple reaction

1-

2

time from the choice reaction time, he could determine the

exact time for each mental process (8,29).

Wundt's psychological laboratory followed Donders'

lead and attempted to obtain definite times for mental pro-

cesses such as attention, perception, association and choice

(29). One of Wundt's first students, Cattel, wrote his dis-

sertation on The Time Taken Up By Cerebral Operations. But,

it was Cattel and Dolley in 1893 who concluded that the velo-

city of the "nervous impulse" cannot be measured by reaction

time methods, including Donders t method of "elimination by

subtraction" (8). Thus, it was shown that reaction time ex-

periments did not necessarily have to be tied to the measure-

ment of mental processes but could be an independent area

of study.

Although attempts to link reaction time with mental pro-

cesses have generally proved fruitless, nonetheless, reaction

time tasks have been included throughout early intelligence

tests, have been used in attempts to predict an individual's

general behavior, have been studied in schizophrenics and

manic-depressives and have been predicted based on an indi-

vidual's physique according to Sheldon's conception of endo-

morphic, mesomorphic and ectomorphic factors in body

build (8,10,29).

In his attempts to measure mental processes, Donders

laid the foundation for the study of choice reaction times.

3

He distinguished between three types of reactions: the a,

the b and the c reactions. The a reaction involved a single

stimulus with a single response required each time the stimu-

lus occurred; the b reaction consisted of two stimuli and two

corresponding responses; and, the c reaction had two stimuli

but only one response with the subject responding to one

stimulus and not the other. The a reaction is a simple

reaction time; the b reaction requires stimulus categori-

zation and response selection (choice reaction time); and,

the c reaction requires stimulus categorization only (3,23).

In 1865, Donders and DeJaeger attempted the first study

of the psychological factors influencing simple and choice

reaction times; however, their research was still basically

directed toward the measurement of the mental processes

involved in a reaction time task (8,29).

One of the important derivatives of the early reaction

time studies was the realization that individual differences

in reaction time were often quite varied even when the sub-

ject was "trying his best" throughout the test (8,29).

Although this realization could have lead to the abandon-

ment of reaction time studies, it ultimately resulted in the

investigation of the varying conditions which caused an indi-

vidual's reaction time to fluctuate so greatly. Unfortunately,

the results of these studies have often been as questionable

as those of the early reaction time studies. Thus, reaction

4

time was studied not as a finite measurement of cerebral

operations but as a phenomenon deserving of further

research (8).

Studies during this period of time revealed that some

of the physiological factors which produced a decrease in a

subject's reaction time included an increase in body tem-

perature, an increase in pulse rate and performance of

strenuous physical exercise. Additional studies revealed

physiological factors that resulted in increases in reaction

time. It was shown that anoxia tends to increase an indivi-

dual's reaction time, maintaining a somewhat constant rate,

until the lack of oxygen becomes extreme. Conversely, small

doses of alcohol decrease reaction time, but only for a short

period; eventually, there is an increase in reaction time

with greater amounts of alcohol. Caffein generally has little

effect on simple reaction time but does cause a decrease in

choice reaction time when consumed in large quantities (26,29).

In addition to physiological factors, motivational

factors have also been considered. Cattel found that varying

the subject's incentive would affect subsequent reaction

times (8). The motivational factors considered have varied

from punishment by electrical shock for slow times to

monetary rewards for fast reaction times (16). Many others

since Cattel have investigated various motivational factors,

and their results have been conflicting. These conflicts have

5

been due to the differences in both the motivational factors

utilized from study to study and the various types of reaction

time tasks employed.

Survey of Literature

Cattel (8) was one of the first individuals to note the

effect of motivation on a subject's reaction time. Since

then, the majority of the recent motivational studies con-

cerning reaction time have stemmed from the early work of

Johanson (16). He found that the speed of reaction may be

increased by providing the subject with ongoing knowledge of

his performance. Church and Camp (5) also found that, in a

simple reaction time task, subjects provided with knowledge

of results of performance were significantly faster than

those who were deprived of this knowledge of results.

McCormack, et al. (18) reported identical findings when using

knowledge of results of performance in another simple reaction

time task. But, their study also indicated that, for the

control conditions only, reaction time increased with time

on task. Thus, the knowledge of results, in addition to pro-

viding quicker reaction times, also appears to maintain a

high level of motivation for the duration of the task.

Sipowicz, et al. (22) have obtained similar findings

using knowledge of results and reward in a simple vigilance

task. Their subjects maintained a high level of vigilance in

6

the knowledge of results and reward conditions while the con-

trol conditions had a typical vigilance decrement. Based on

these findings, they concluded that knowledge of results and

reward were effective motivational techniques. In studies by

Weidenfeller, et al. (28), using knowledge of results, and

Lucaccini, et al. (17), employing monetary rewards, the

typical time on task vigilance decrement was not found in

their experimental condition--further evidence supporting

the effect of motivational factors.

In studies dealing with schematic concept formation,

Glasgow, et al. (9) and Pearre and Jones (20) have found that

the performance of their subjects was not significantly

above chance when knowledge of results was not provided. In

another study dealing with schematic concept formation tasks,

Brown, et al. (4) found that the subjects in the knowledge

of results of performance condition performed worse than the

subjects in the control condition. Conversely, Hollier and

Evans (14), in a study of schematic concept formation with

linguaform patterns did not find a negative effect as in the

previously mentioned study; however, findings from their know-

ledge of results of performance conditions were not signi-

ficantly different from their control condition.

In Sternberg's (25) study on character recognition,

knowledge of results of performance had a significant

positive motivational effect. Additionally, monetary

7

incentives were found to increase performance in vigilance

tasks studied by Bergum and Lehr (2) and Smith, et al. (24),

with the results reported to be due to the experimentally

induced changes in the motivational level of the reward

groups. The effects of monetary reward seemed evident in the

past. Edwards (6,7) has stated that money is one of the best

final value measures in that it will fit almost any problem,

it is unambiguous and tangible and it has useful motivating

properties. Furthermore, it has been shown that subjects will

try to maximize their expected financial gain. This maxi-

mization of return and resultant increased motivational

level are of crucial importance in experiments dealing with

problem solving, conceptualizing and decision making type tasks.

In an effort to determine whether knowledge of results

is a motivational factor similar to monetary reward or an

informational factor having secondary motivational influence,

Hardesty, et al. (12) mechanically presented knowledge of

results (information only) while an observer presented know-

ledge of results (information plus evaluative-motivational

input) in a monitoring task. The results indicated that the

subjects in the observer-presented condition were signifi-

cantly better at the monitoring task than either the subjects

in the mechanically-1presented condition or in the control

(no information) conditions. Furthermore, the results of

the mechanically-presented condition were not different from

8

the control condition. These results were interpreted as

indicating that the observer-presented knowledge has an

evaluative-motivational effect on the subject, thereby in-

ducing a greater need to achieve. In similar studies,

Ammons and Ammons (1) have also stated that the processes

related to observer-presented knowledge of results are not

informational but motivational in character.

Church and Camp (5) indicated that a non-significant

finding of their reaction time study was that all reaction

times decreased with time on task (practice effect) with the

greatest decrease in the knowledge of results condition.

Also, Mowbray and Rhoades (19) and Hyman (15) found a signi-

ficant practice effect in their studies of reaction time.

Teichner and Krebs (27) have reported that practice effects

are one result of the number of trials in reaction time

studies. On the other hand, Woodworth and Schlosberg (29)

stated that the average subject continues to reduce his

reaction time over several hundred trials with the largest

practice effect found in the first fifty to one hundred

trials. In addition, these studies showed the practice effect

to be even greater in choice reaction time tasks.

In addition to widely varying individual differences in

reaction times, Goodenough (10) has found a significant dif-

ference between the simple reaction times of males and fe-

males. In these studies, males reacted somewhat more quickly

9

and with a lower variability from trial to trial; however,

a great deal of overlapping between sexes was noted.

Teichner (26) also mentions that the weight of evidence in

reaction time studies indicates that a sex difference

favoring men does exist. In a study by Hodgkins (13), it

was found that a sex difference was greatest at the college

age level. Overall, between the ages of twelve to fifty-four,

the males were found to be significantly faster than fe-

males of the same age. Woodworth and Schlosberg (29) con-

curred with the previous findings stating that males have

shorter reaction times than females of the same age.

Statement of Problem

In the past, most of the reaction time studies con-

cerning different motivational levels have used knowledge

of results of performance or reward in a simple reaction time

task (5,16,18). The effects of the motivational level have

not always been very substantial due to the inherent dif-

ficulty of using a simple reaction time task. The problem

connected with using a simple reaction time task is that the

subject is prohibited from responding much faster regardless

of his level of motivation because of a "ceiling effect."

The "ceiling effect" is a result of the physical limitations

prohibiting a response faster than approximately 140 to 200

milliseconds for a visual stimulus-key response simple reaction

10

time task. Furthermore, the trial to trial variability is

usually greater than the decrease in simple reaction times

due to the motivational factors.

Donders' b reaction time tasks, requiring both stimulus

categorization and response selection, have been explored in

the past; his own experimentation revealed the b reaction

times to be about 100 milliseconds longer than the a

reaction (simple reaction) times (29). However, Gottsdanker

(11) has found that for a simple b reaction (simple-choice

reaction,) the resultant reaction times are no greater than

simple reaction times. But, Broadbent and Gregory (3) and

Rabbitt (21) have stated that in a highly compatible

situation such as those involved in simple-choice reactions,

the usual tendency for reaction time to increase with the

number of alternative responses will not occur. Thus, it

was reasoned that if motivational factors are to be considered

in a reaction time task, the task must be complex enough to

produce significantly larger reaction times in order to

avoid the "ceiling effect." Therefore, the present study

was designed to investigate more fully the general relation-

ship between motivational factors and reaction time by using

a more complex task.

Specific Purposes of Study

The specific purposes of this study were (a) to deter-

mine the relative effects of different motivational factors

11

on reaction time; (b) to ascertain to what extent males would

respond differently from females in terms of reaction time;

and, (c) to ascertain the joint effects of the two major

variables of motivation and sex on reaction time.

Additionally, this study was designed (a) to determine

the relative effects of different motivational factors on

practice effects; (b) to determine to what extent males would

react differently from females in terms of practice effects;

and, (c) to ascertain the joint effects of the two major

variables of motivation and sex on practice effects.

The motivational factors involved were those widely

used in reaction time and vigilance studies--knowledge of

results of performance and monetary reward. The difference

between the motivational levels was considered and a pre-

diction made that the fastest reaction times would be ob-

served in the reward condition, the next fastest times in

the knowledge of results condition and the slowest times in

the control condition. Additionally, the difference

between the motivational levels was considered with respect

to the practice effects. The practice effect was predicted

to be the greatest in the most highly motivating condition

(reward), with the knowledge of results and then the control

condition showing decreasing practice effects.

Hypotheses

This study was designed to test empirically the following

hypotheses:

Hypothesis l.--Subjects in the reward condition will

produce significantly faster mean reaction times than (a) the

subjects in the knowledge of results condition, and (b) the

subjects in the control condition.

Hypothesis 2.--Subjects in the knowledge of results

condition will produce significantly faster mean reaction

times than subjects in the control condition.

Hypothesis 3.--Subjects in the reward condition will

have significantly greater practice effects than (a) the

subjects in the knowledge of results condition, and (b) the

subjects in the control condition.

Hypothesis 4.--Subjects in the knowledge of results

condition will have significantly greater practice effects

than subjects in the control condition.

CHAPTER BIBLIOGRAPHY

1. Ammons, R. B., and C. H. Ammons, "Some Knowledge ofPerformance Concepts," Psychological Reports, 2(1956), 65-66.

2. Bergum, B. 0., and D. J. Lehr, "Monetary Incentives andVigilance," Journal of Experimental Psychology, 67(1964), 197-198.

3. Broadbent, D. E., and M. Gregory, "Donders' B- and C-Reactions and S-R Compatibility," Journal ofExperimental Psychology, 63 (1962), 575-578.

4. Brown, B. R., D. W. Walker, and S. H. Evans, "SchematicConcept Formation as a Function of ConstraintRedundancy and Knowl edge of Resul ts, " Psychonomi cScience, 11 (1968), 75-76.

5. Church, R. M. and D. S. Camp, "Change in Reaction-Timeas a Function of Knowledge of Results," AmericanJournal of Psychology, 78 (1965), 102-106.

6. Edwards, W., "Costs and Payoffs Are Instructions,"Psychological Review, 68 (1961), 275-284.

7. , "Optimal Strategies for Seeking Information:Models for Statistics, Choice Reaction Times, andHuman Information Processing," Journal of MathematicalPsychology, 2 (1965), 312-329.

8. Garrett, H. E., Great Experiments in Psychology, New York,D. Appleton-Century, 1934.

9. Glasgow, J. M., and E. C. Jones, "Effects of Knowledgeof Results on Schematic Concept Formation withLinguaform Patterns," Psychonomic Science, 19(1970), 347.

10. Goodenough, F. L., "The Development of the ReactiveProcess from Early Childhood to Maturity," Journalof Experimental Psychology, 18 (1935), 431-450.

13

14

11. Gottsdanker, R., "Choice Reaction Time and the Natureof the Choice Response," Psychonomic Science, 14(1969)5, 257-258.

12. Hardesty, D., D. Trumbo, and W. Bevan, "Influence ofKnowledge of Results on Performance in a MonitoringTask," Perceptual and Motor Skills, 16 (1963),629-634.

13. Hodgkins, J., "Reaction Time and Speed of Movement inMales and Females of Various Ages," ResearchQuartery 34 (1963), 335-343.

14. Hollier, J., and S. H. Evans, "Schematic ConceptFormation with Linguaform Patterns," PsychonomicScience, 9 (1967), 89-90.

15. Hyman, R., "Stimulus Information as a Determinant ofReaction Time," Journal of Experimental Psychology,45 (1953)3, 188-196.

16. Johanson, A. M., "Influence of Incentive and Punishmenton Reaction-Time," Archives of Psychology, 8(1922), 1-53.

17. Lucaccini, L. F., A. Freedy, and J. Lyman, "MotivationalFactors in Vigilance: Effects of Instructions onPerformance in a Complex Vigilance Task," Perceptualand Motor Skills, 26 (1968), 783-786.

18. McCormack, P. D., F. R. S. Binding, and J. Chylinski,"Effects on Reaction Time of Knowledge of Results ofPerformance," Perceptual and Motor Skills, 14(1962), 367-372.

19. Mowbray, G. A., and M. V. Rhoades, "on the Reduction ofChoice Reaction Times with Practice," QuarterlyJournal of Experimental Psychology, 11 (1959) , 16-23.

20. Pearre, J. C., and E. C. Jones, "Effects of Knowledgeof Results on Schematic Concept Formation,"Psychonomic Science, 12 (1968), 367-368.

21. Rabbitt, P. M. A., "Effects of Independent Variationsin Stimulus and Response Probability," Nature,183 (1959)5, 1212.

15

22. Sipowicz, R. R., J. R. Ware, and R. A. Baker, "TheEffects of Reward and Knowledge of Results on thePerformance of a Simple Vigilance Task," Journalof Experimental Psychology, 64 (1962), 58-61.

23. Smith, E. E., "Choice Reaction Time: An Analysis ofthe Major Theoretical Positions," PsychologicalBulletin, 69 (1968), 77-110.

24. Smith, R. L., L. F. Lucaccini, and M. H. Epstein,"Effects of Monetary Rewards and Punishments onVigilance Performance," Journal of AppliedPsychology, 51 (1967), 411-416.

25. Sternberg, S., "Two Operations in Character Recognition:Some Evidence from Reaction-Time Measurements,"Perception and Psychophysics, 2 (1967), 45-53.

26. Teichner, W. H., "Recent Studies of Simple ReactionTime," Psychological Bulletin, 51 (1954), 128-149.

27. , and M. J. Krebs, "Laws of VisualChoice Reaction Time," Psychological Review, 81(1974), 75-98.

28. Weidenfeller, E. W., R. A. Baker, and J. R. Ware, "TheEffects of Knowledge of Results (True and False) onVigilance Performance," Perceptual and Motor Skills,14, (1962), 211-215.

29. Woodworth, R. S., and H. Schlosberg, ExperimentalPsychology, New York, Holt, 1958.

CHAPTER II

METHOD

Subjects

The subjects were twenty-six male and thirty-two female

students enrolled in undergraduate psychology classes at

North Texas State University. The mean age of the males was

21.2 years and the mean age of the females was 22.3 years.

Apparatus

A visual choice reaction time apparatus as shown in

Figure 1 was used to allow presentation of up to nine stimulus

lights at any one time.

)2clear stimulus

lights

red responsebuttons

Fig. 1 -- Visual choice reaction time apparatus

In addition to allowing any number of lights to be presented,

the stimulus lights could also be presented in any order by

means of jacks located on the experimenter's side of the

apparatus. The apparatus shown in Figure 1 could also be

16

0 1.6 46 410 0 0 00 0

17

independently programmed to select any one of the eight red

response buttons as the correct answer; this was accomplished

by means of a rotary switch located on the experimenter's

side of the apparatus. The visual choice reaction time

apparatus shown in Figure 1 was grey in color and measured

17 1/2 inches wide and 8 inches high.

A stop clock timer (Clock/Counter Model 54519, Lafayette

Instrument Company) was connected to the reaction time

apparatus to permit measurement of the subjects' reaction

time to the nearest hundredth of a second.

A twenty-eight-volt D.C. power supply was connected to

the reaction time apparatus and a start button. The start

button turned on the preselected stimulus lights and started

the clock timer. When the subject responded by pressing the

correct response button, the stimulus lights and the clock

timer were turned off. Also, a standard stopwatch was used

to measure the foreperiods.

Experimental Procedure

Control Condition Instructions

All subjects were given the following verbal instructions

which constituted the control condition; additional

instructions to be described were given to subjects in the

other two conditions.

In this experiment, I will measure the speedwith which you can press a key in response to a

18

number of stimuli. There are nine lights and eightkeys on the apparatus in front of you. Each ofthese lights counts as one stimulus. The keys arenumbered from zero to seven starting from yourleft. Before each trial, I will say "ready" andshortly thereafter the lights will come on. Youare to count the number of lights and subtract thecount from the number eight. Quickly press thekey which represents the correct answer to themathematical problem with the index finger of yourdominant hand. If you press the wrong key, onethat does not turn the lights off, correct your-self as quickly as you can. In between trials,keep your hand resting on the table in front ofthe apparatus. Any questions?

Knowledge of Results Instructions

In addition to the above instructions, the subjects in

the knowledge of results condition were given the following

verbal instructions: "Immediately after each trial, you will

be told how many seconds it took you to press the correct

key after the stimuli were presented."

Reward Condition Instructions

The reward condition subjects were given the following

additional verbal instructions:

A pencil and a sheet of paper have beenprovided; the paper has two columns, one labeled'faster' and one labeled 'slower.' After'eachtrial, I will tell you if your response wasfaster of slower than a predetermined responsetime. You are to keep a stroke tally of theresponses in the proper column; when all thetrials have been completed, you will receivetwenty-five cents for every response in the'faster' column that exceeds the number in the'slower' column. You can earn as much as $5.25in the fifteen minutes that you will be here.That is equivalent to earning $21.00 per hour.

19

After receiving the appropriate instructions, each

subject was given twenty-one trials. For each trial problem,

the experimenter said "ready", waited one, two, or three

seconds (the foreperiod), and then pressed the start button.

The subject's correct response turned off the stimulus lights

and the timer. The experimenter then recorded the subject's

reaction time to that particular trial problem.

The trial problems were presented at a rate of no less

than twenty-five and no more than forty seconds between

trials.

The foreperiods, the time between the "ready" signal

and the onset of the stimulus, were randomly assigned to

each of the trial problems. The trial problems consisted

of two random assignments: the number of lights presented

and which lights would be presented. The number of lights

presented determined the correct response: if two lights

were turned on then the correct response was six (eight

minus two); if five lights were turned on then the correct

response was three (eight minus five); and, if eight lights

were turned on the correct response was zero (eight minus

eight). Eight different answers would have been possible

on the apparatus using buttons numbered zero through seven,

but the number one button malfunctioned at the beginning

of this study and, therefore, was not used. The seven

remaining responses (0,2,3,4,5,6,and 7) were randomly

20

assigned within three blocks of seven trials each. Thus,

each response was represented once in the first seven,

middle seven, and final seven trials.

For each trial problem, the lights which were turned on

(stimulus configuration) were also randomly assigned. Thus,

if the number of lights to be presented was three, three

lights were randomly assigned to that particular problem.

The lights were numbered one through nine, from left to

right, on the experimenter's side of the apparatus only.

For purposes of illustration, Table I contains the

stimulus configurations and foreperiods for all twenty-one

trial problems used in this experiment.

21

TABLE I

STIMULUS CONFIGURATIONS AND FOREPERIODS

Number ofBlock Trial Stimuli Stimulus Foreperiod Correct

Presented Configuration Response

1 2 1,3 3 62 4 4,7,8,9 2 43 5 1,2,4,5,8 3 3

1 4 6 1,2,6,7,8,9 2 25 8 1,2,3,4,5,6,7,8 2 06 1 3 1 77 3 1,5,9 1 5

8 8 1,3,4,5,6,7,8,9 3 09 2 4,7 2 6

10 5 1,2,6,7,9 1 32 11 1 7 3 7

12 3 2,3,8 2 513 4 3,4,6,8 1 414 6 2,4,5,7,8,9 3 2

15 6 3,4,6,7,8,9 1 216 2 8,9 1 617 5 3,4,5,6,7 2 3

3 18 3 2,3,6 3 519 1 6 2 720 8 2,3,4,5,6,7,8,9 1 021 4 1,4,7,8 3 4

The subjects in the knowledge of results condition

were told their actual response time after each trial. The

subjects in the reward condition were told to put a stroke

under the "faster" column if their response was equal to or

faster than 1.80 seconds and a stroke under the "slower"

column if their response was slower than 1.80 seconds. At

22

the completion of the experimental session, the reward

subjects were instructed to total each column and subtract

the "slower" responses from the "faster" responses. The

experimenter then paid the subjects at the rate of twenty-

five cents for every response in the "faster" column that

exceeded the number of responses in the "slower" column as

per the reward condition instructions.

The cut-off point of 1.80 seconds was based on the first

four subjects run in the present experiment. The first four

subjects were not in the reward condition and consisted of

one male and one female in each of the control and knowledge

of results conditions. The 1.80 second cut-off point was

selected to reward the subjects with a "faster" response

forty-three per cent of the time. The cut-off points

considered and their projected percentage of "faster"

responses are presented in Table II.

TABLE II

CUT-OFF POINTS IN SECONDS AND PERCENTAGEOF PROJECTED "FASTER" RESPONSES

Cut-off Points Percentage of Projected "Faster" Responses

1.60 . . . . . . . . . . . . . . . . 351.70 . . . . . . . . . . . . . . . . 381.80 . . . . . . . . . . . . . . . . 431.90 . . . . . . . . . . . . . . . . 452.00 . . . . . . . . . . . . . . . . 51

23

Although Church and Camp (1) successfully used a

similar criterion in their study that provided thirty-three

per cent "faster" responses, in this study forty-three per

cent projected "faster" responses was selected as the

criterion. It was decided to use a higher cut-off point in

this study due to the right minus wrong payoff scheme, a

method not used by Church and Camp (1). Because of this

payoff scheme, the reward condition subjects had to have

more than fifty per-cent "faster" responses in order to

receive any monetary reward. Since the projection was

calculated from the two lower motivating conditions,

knowledge of results and control, it was decided to use a

payoff rate of less than fifty per cent anticipating that

the motivation of a monetary reward would result in achieve-

ment of a greater percentage of "faster" responses for the

subjects in the reward condition. Unfortunately, the 1.80

second cut-off point ultimately selected actually yielded

only an average of forty-six percent "faster" responses.

The subjects were randomly assigned to one of the

three motivation conditions: reward, knowledge of results

and control.

Experimental Design

The basic design was a three-dimensional analysis of

variance in which the three major factors and their

respective treatment categories were: sex (male-female);

24

motivation (reward-knowledge of results-control); and trials

(twenty-one individual or three blocks of seven each). The

dependent variable was the subject's reaction time for each

of the twenty-one trials.

For the reaction time analysis, the individual trials

were used in a 2 x 3 x 21 three-dimensional analysis of

variance, and for the practice effect analysis, the subjects'

three block means were used in a 2 x 3 x 3 three-dimensional

analysis of variance. The block means were derived from each

subject's reaction times for the first seven, middle seven

and final seven trials.

CHAPTER BIBLIOGRAPHY

1. Church, R. M., and D. S. Camp, "Change in Reaction-Timeas a Function of Knowledge of Results," AmericanJournal of Psychology, 78, (1965) , 102-106.

25

CHAPTER III

RESULTS

Statistical Analysis

The results obtained and the statistical analyses of

those results are reported in the present chapter. The

major objective was to determine the joint and separate

effects of motivational level and sex of the subjects on

their reaction times to a complex choice reaction time task.

The secondary objective was to ascertain the relative effects

of these same variables on practice effect in which the

twenty-one trials were divided into three blocks consisting

of: the first seven, the middle seven and the final seven

trials. The present chapter has been divided into two major

subsections, each one corresponding to the two major analyses.

The reaction times for all subjects for each trial are

presented in the appendix.

Reaction Time

Using each male and female subject's reaction times,

means and standard deviations were obtained for each

condition, for all conditions combined, and for all subjects

in each condition. The means and standard deviations are

presented in Table III.

26

27

TABLE III

MEANS AND STANDARD DEVIATIONS OF REACTIONTIMES FOR ALL CONDITIONS

MotivationalConditionSex Statistic Reward Knowledge Control Main Effect

of Results --Sex

Mean 2.10 2.10 2.15 2.11

Male SD 1.29 1.17 1.49 1.33

N 8 9 9 26

Mean 2.68 2.57 2.17 2.48

Female SD 1.97 1.83 1.36 1.76

N 11 11 10 32

Mean 2.44 2.35 2.16 2.32Main

Effect--, SD 1.74 1.58 1.42 1.59Motivation

N 19 20 19 58

In reference to Table III, a very prominent finding was

the fact that the main effect mean for females (2.48) was

somewhat higher (slower reaction time) than the main effect

mean for males (2.111). Additionally, the main effect means

for the two experimental groups (2.44 and 2.35) were also

higher than the main effect mean for the control group (2.16).

28

In the interest of clarity, the male and female means

for each motivational condition from Table III are

graphically presented in Figure 2.

2.8

2.7 FemalesE

2.6

o -o 2.5

' e 2.3+.) 0

u 2.4

ra)

Qj 2.2

2.1 Males

2.0 -

Reward Knowledge ControlMotivational Condition

Fig. 2--Male and female means as a function ofmotivational condition.

Inspection of Figure 2 reveals that the females were

generally slower in their reaction times than were the males

in all motivational conditions with the least difference

between the sexes being reflected by the control condition

subjects. However, the females achieved their fastest

reaction times, and the males displayed their slowest

reaction times in the control condition, but the difference

appeared to be very slight.

29

The required assumption of homogeneity of variance,

underlying the use of the statistical design, was tested by

Hartley's Fmax statistic as presented by Winer (1). The

observed value of Fmax was 2.83 which did not exceed the

critical value of Fmax = 6.92 (df = 6,10, p = .05); thus,

the hypothesis of homogeneity of variance was regarded

tenable; therefore, an analysis of variance was then

performed on the basic criterion scores.

The reaction times were then placed in the sex x

motivation x trials analysis of variance scheme and analyzed.

A summary of the analysis of variance performed on these

data is presented in Table IV.

TABLE IV

SUMMARY OF ANALYSIS OF VARIANCE OF THESEX x MOTIVATION x TRIAL DESIGN

Source of Variation SS df MS F

Between subjects 332.38 57 . .Sex 37.48 1 37.48 7.47**Motivation 11.64 2 5.82 1.16Sex x motivation 17.81 2 8.90 1.77Error between 260.98 52 5.02

Within subjects 2737.47 1160 . .Trial 665.92 20 33.30 18.36**Sex x trial 32.46 20 1.62 0.90Motivation x trial 62.20 40 1.56 0.86Sex x motivation

x trial 56.51 40 1.41 0.78Error within 1886.22 1040 1.81 .

**Significant at .01 level

30

Adopting a p = .01 level of significance as critical,

the appropriate value for the test between the main effect

means for sexes was F = 7.17 (df = 1,52). Since the

observed F ratio of 7.47 was larger than the critical F value

the difference between the male and female mean reaction

times was shown to be statistically significant. Thus, on

an average basis over all trials as a whole, the males

reacted significantly faster (M = 2.11) than did the females

(M = 2.48) regardless of motivational conditions. The other

significant main effect difference was the within trial F

ratio of 18.36 which also exceeded the p = .01 level of

significance with a critical value of F = 1.89 (df = 20,

1040). The latter finding indicates that at least two of

the twenty-one trial problems were significantly different

in the amount of time required to respond. This significant

difference within subjects' trials was most probably a

result of: (a) a difference in complexity level between

various trial problems, and/or (b) a practice effect, to be

discussed in the following section.

Practice Effect

As a subject becomes familiar with the task and apparatus

in any experiment, the usual result is an improvement in the

performance of that task. In a reaction time task, the

practice effect is evidenced by progressively faster reaction

times as the number of trials increases.

31

Using the subjects' reaction times, the preceding analysis

of variance indicated that at least two of the twenty-one

trial problems were significantly different in the amount of

time required to respond. As was stated earlier, this

difference could be due to various complexity levels of the

trial problems, a practice effect, or some combination of the

two. The effects of the seven different complexity levels

were equalized by presenting each level of complexity

(response) to the subjects three times, once in each block of

seven trials. Thus, by obtaining means for each subject for

the three blocks, the complexity levels were equalized and

any difference between the blocks showing a decrease toward

the last block should be due to the practice effect.

Using each subject's trial block means as criterion

scores, a 2 x 3 x 3 (sex x motivation x block) analysis of

variance was performed. Table V contains a summary of the

analysis.

32

TABLE V

SUMMARY OF ANALYSIS OF VARIANCE OF THESEX x MOTIVATION x BLOCK DESIGN

Source of Variation SS df MS F

Between subjects 47.48 57 .Sex 5.36 1 5.36 7.47**Motivation 1.66 2 0.83 1.16Sex x motivation 2.54 2 1.27 1.77Error between 37.28 52 0.72

Within subjects 44.15 116 .Block 14.19 2 7.09 27.11**Sex x block 0.88 2 0.44 1.68Motivation x block 0.62 4 0.16 0.59Sex x motivation

x block 0.26 4 0.07 0.25Error within 27.22 104 0.26

**Significant at .01 level

Adopting a p = .01 critical level of significance, the

appropriate value for the test between the sexes was F = 7.17

(df = 1,52). Since the observed F ratio of 7.47 was larger

than the critical F value, the difference between the male

and female block means was shown to be statistically

significant. Thus, with the trial complexity equalized and

on an average basis, the males reacted faster (M = 2.11)

than did the females (M = 2.48).

The within subjects block F ratio of 27.11 was also

statistically significant, exceeding the p = .01 level of

significance with a critical F value of F = 4.82 (df = 2,104).

33

Therefore, with the trial complexity equalized in this

analysis, at least two of the blocks were significantly

different in the amount of time required to respond. Thus,

a significant overall practice effect was in evidence.

There were no significant interactions, but both sex

and trial blocks were significant. Since only these two

variables were significant, their corresponding means are

included in the text as reflected in Table VI. The

remaining means are presented in the appendix.

TABLE VI

MEANS AND STANDARD DEVIATIONS OF SEXAND TRIAL BLOCK REACTION TIMES

Sex Statistic Trial Block Main Effect

1 2 3 -- Sex

M 2.41 2.06 1.88 2.11Male SD 0.65 0.51 0.42 0.57

N 26 26 26 78

M 2.96 2.39 2.09 2.48Female SD 0.79 0.75 0.62 0.80

N 32 32 32 96

Main M 2.71 2.24 2.00 2.32Effect SD 0.77 0.67 0.55 0.73

-- Blocks N 58 58 58 174

Inspection of Table VI reveals that for both sexes the

second block mean is lower than the first and the third

block mean is lower than the second. Thus, the significant

34

difference between the blocks as indicated by the analysis

of variance in Table V is due to a practice effect.

The simple effect means from Table VI are shown

graphically in Figure 3.

3.0 ~Females

E 2.8

'1e

4 U 2.4 MalesU CD)

2.2

2.0

1.82 3

Block

Fig. 3--Practice effect for males and females

Inspection of Figure 3 reveals the significant difference

between the sexes as shown in Tables IV and V and also

reveals the significant practice effect as shown in Table V.

Tenability of Hypotheses

Hypothesis 1 stated that the subjects in the reward

condition would produce significantly faster mean reaction

times than; (a) the subjects in the knowledge of results

condition, and (b) the subjects in the control condition.

Hypothesis 2 of the present study stated that the subjects

in the knowledge of results condition would produce

35

significantly faster mean reaction times than subjects in

the control condition.

Hypotheses 1 and 2 were rejected because, as Table IV

indicates, no significant difference existed between any of

the motivational conditions. The between subjects

motivational condition observed F ratio was 1.16 with a

critical value of F = 3.18 (df = 2.52, p = .05). These

results indicated that the relative effects of the

motivational variables used in the present study were not

significantly different.

Table IV also indicates a significant difference

between the male and female subjects with an observed F ratio

of 7.47 with a critical value of F = 7.17 (df = 1,52,

p = .01). Because of the significant difference between the

sexes in the present study, Hypotheses 1 and 2 were also

considered with this sex difference in mind. Hypotheses 1

and 2 were still rejected because the sex x motivation

interaction F ratio from Table IV of 1.77 was less than the

critical value of F = 3.18 (df = 2,52, p = .05).

Hypothesis 3 stated that subjects in the reward

condition would have significantly greater practice effects

than: (a) the subjects in the knowledge of results condition,

and (b) the subjects in the control condition. Hypothesis 4

of the present study stated that subjects in the knowledge

of results condition would have significantly greater

36

practice effects than subjects in the control condition.

Table V indicates that no significant difference existed

between any of the motivational conditions in terms of block

mean reaction times. The between subjects motivational

condition observed F ratio was 1.16 with a critical value of

F = 3.18 (df = 2,52, p = .05). These results indicated that

in terms of block mean reaction times, the relative effects

of the motivational variables were not significantly

different. Since the motivational conditions were not

significantly different, Hypotheses 3 and 4 were rejected.

Further inspection of Table V, however, indicates that

a significant overall practice effect occurred. This

significant practice effect was evidenced by: (a) the

observed within subjects block F ratio of 27.11 which

exceeded the critical value of F = 4.82 (df = 2,104,

p = .01); and, (b) the progressively faster block reaction

times as shown in Figure 3.

CHAPTER BIBLIOGRAPHY

1. Winer, B. J., Statistical Principles in ExperimentalDesign, New York, McGraw-Hill Book Company, 1962.

37

CHAPTER IV

DISCUSSION OF RESULTS

The results of this study do not appear to be in agree-

ment with the results of most reaction time and vigilance

studies. Conflicting evidence will be indicated and attempts

to account for the differences between the present study and

those of others are presented in the following paragraphs.

Hypothesis 1 stated that subjects in the reward condition

would produce significantly faster mean reaction times than

would the subjects in both the knowledge of results condition

and the control condition. The results of this study have

indicated no significant difference between any of the moti-

vational conditions; therefore, the effects of the moti-

vational variables used in this study were not statistically

different. This finding is in direct disagreement with the

following vigilance studies conducted in the past using mone-

tary rewards identical in design to those used in the present

study. Bergum and Lehr (3) rewarded their subjects twenty

cents for each correct response and twenty cents was deducted

for each incorrect response. Smith, et a!. (24), using the

twenty-cent condition, plus an additional ten-cent condition,

obtained results indicating that the twenty-cent condition

was significantly higher than the ten-cent condition

38

39

and the ten-cent condition higher than the control group.

Sipowicz, et al. (23) gave each reward condition subject

three dollars and then deducted increasing amounts with

each miss or incorrect response. Lucaccini, et al. (17)

paid the reward subjects a flat rate of two dollars, with

no deductions, and found the reward condition performing

significantly better than the controls.

The results of the present experiment not only disagreed

with the preceding studies, but conversely, the reward

condition performed at a slower overall rate than any of the

other motivational conditions. Because the reward design was

essentially identical to several of the above designs,

this finding may have been due to the introduction of a

complex-choice reaction time task. The specifics of the

complex-choice reaction time task will be discussed later

in this chapter.

Hypothesis 2 stated that subjects in the knowledge of

results condition would produce significantly faster mean

reaction times than subjects in the control condition. The

results of the present study disagreed-with all of the

following simple reaction time studies (and most of the

following vigilance studies) conducted in the past. Church

and Camp (6) and McCormack, et al. (18) presented knowledge

of results by way of a green light for a "faster" response

and a red light for a "slower" response. Johanson (15)

40

provided his subjects with ongoing knowledge of their per-

formance similar to that used in this study. The following

are vigilance studies which disagree with the present study.

In experiments by Sipowicz, et al. (23) and Weidenfeller,

et al. (29) in which knowledge of results was provided by

lights similar to the preceding reaction time studies,

the results indicated that knowledge of results significantly

improved vigilance performance. Hardesty, et al. (11) found

that when presenting knowledge of results mechanically, as

with the lights, performance was significantly poorer than

when the knowledge of results was provided by an individual

who was present in the experimental situation.

The results of the present study agree with some con-

cept formation experiments but disagree with others. More

specifically, Glasgow and Jones (9) and Pearre and Jones (22)

found that knowledge of results had a positive motivational

effect in that their knowledge of results experimental

subjects performed significantly above chance. On the other

hand, Brown, et al. (5) found negative effects since their

knowledge of results condition subjects performed worse

than their control condition subjects. Hollier and Evans (13)

found that a knowledge of results treatment was not signi-

ficantly different in performance from a control condition.

The two preceding studies generally agree with the present

study in that the knowledge of results condition was not

41

significantly different from the control condition, but it

was slower than the control condition for the females only.

In Sternberg's (25) study of character recognition, the

subjects in the knowledge of results condition were told

their actual reaction times, as in the present study, but

the knowledge of results had a significantly positive moti-

vational effect, unlike the present study.

In the present study, it will be recalled that knowledge

of results was provided by giving the subject his actual

reaction time after each trial; this method is identical to

the method used in one of the preceding studies and similar

to others. The results may have been due to the method of

presentation of the knowledge of results and/or due to the

complex-choice reaction time task utilized in this experiment.

Again, the specifics of the complex-choice reaction time task

will be discussed later in this chapter.

Hypothesis 3 stated that subjects in the reward con-

dition would experience significantly greater practice effects

than would subjects in the knowledge of results condition and

the control condition. Hypothesis 4 stated that subjects in

the knowledge of results condition would have significantly

greater practice effects than subjects in the control con-

dition. The present study revealed significant practice

effects but no significant difference between the motivational

conditions; thus, both Hypotheses 3 and 4 were rejected. In

42

a simple reaction time task, Church and Camp (6) found

non-significant practice effects; but, unlike the present

study, they indicated that the practice effect was not evi-

dent in the control condition. In another simple reaction

time study using knowledge of results, McCormack, et al. (18)

found a significant practice effect. And, in a simple vigi-

lance task by Sipowicz, et al. (23), the reward and knowledge

of results conditions showed evidence of a practice effect

unlike their control condition. Teichner and Krebs (28) and

Woodworth and Schlosberg (30) stated that in a choice re-

action time task, the practice effect will be evident as an

effect of the number of trials. Their statements do agree

with the significant practice effect found in this study as

evidenced by Figure 3. Also consonant with present results

were those of Mowbray and Rhoades (21) in which it was

stated that in a choice reaction time task requiring a key

to be pressed in response to stimuli lights, a practice

effect will be present in all conditions. A study by Hyman

(14) states that all subjects showed a significant practice

effect from series to series, which is also in agreement

with the findings of the present study.

Hypotheses 3 and 4 were rejected because no significant

difference existed between any of the motivational conditions

in the present study. However, a significant overall practice

effect was evidenced in this study which agrees with the

43

majority of similar experiments reported in the literature.

A practice effect is predicted by a majority of experimenters,

especially in a choice reaction time task; but, unlike the

present study, the practice effects have not always been

significant. The rejection of Hypotheses 3 and 4 was due to

the motivational variables having no significant effect.

The results of the present study are in absolute agree-

ment with previous findings of a sex difference in reaction

time tasks. Males were significantly faster than females

which concurs with the findings of Goodenough (10). She

stated in 1935 that a significant difference exists between

the simple reaction times of males and females with the

males reacting more quickly. Teichner (27) stated that the

weight of the evidence in reaction time studies indicates

that a sex difference does exist and that men are the faster

responding of the sexes. Woodworth and Schlosberg (30) also

stated that males have faster reaction times than females of

the same age. Finally, in a simple reaction time study by

Hodgkins (12), males were found to be significantly faster,

with the greatest difference at the college age level. Thus,

it should be concluded that a significant sex difference re-

mains despite the reaction time task required.

It seems reasonable to hypothesize that most of the non-

significant and conflicting results found in the present

study appear to be due to the type of reaction time task

44

utilized. The predictions from the literature do not indi-

cate that a more complex task should show any difference in

results than a simple reaction time task. This may be because,

in the past, the choice reaction time tasks, similar to

Donders' b reaction, were much simpler than the complex-

choice reaction time task employed in this study. The complex-

choice reaction time task in this study was designed with

the straightforward predictions of several experimenters in

mind. In 1885 Merkel (19) stated that for a choice reaction

time task, the reaction time would increase as the number of

possible alternative signals which could be presented in-

creases. While Brebner and Gordon (4) recently stated that,

when the ensemble size is increased and all items are pre-

sented with equal frequency, the stimulus situation is

changed in two ways. First, more separate categories are

presented to the subject and, second, the probability that

a particular response will be required is reduced. The re-

sultant increase in reaction time could be due to reduced

signal probability, an increase in the number of categories

to be identified or an interaction of both effects. However,

Brebner and Gordon (4) did not differentiate between the

results obtained from more complex choice reaction time

tasks and those of simple reaction time tasks. Falmagne (8)

and Andreas (1) also predict longer reaction times when the

number of stimuli presented and responses required are

45

increased; but, they do not predict any difference other

than longer reaction times. It is conceivable that a com-

plex-choice reaction time task, such as the one used in

the present study, would not follow the predictions of a

simple reaction time study.

The task in the present study was designed to replicate

previous tasks with the exception of one factor, the total

time required to respond to each stimulus configuration. As

suggested by Behar and Adams (2), a ready signal was used

before each stimulus presentation identical to the ones

used in most reaction time studies. Variable foreperiods of

one, two or three seconds were used, as found in the

majority of reaction time studies and as suggested by

Moss (20). The stimuli were presented with lights and the

response was a standard key response, both of which are

used in the majority of reaction time studies. Emerson (7)

suggested that the mean is the most reliable reaction time

statistic providing the best gauge of the aspects of

variation of experimental parameters; thus, the mean was em-

ployed in this study as the major statistic.

After considering all the aforementioned studies, the

major difference still remains as the actual task required,

the complex-choice reaction time task. Laming (16) states

that most of the time required to respond to a choice

reaction time task is dominated by the time spent in

46

choosing a response, while Stone (26) breaks the choice

reaction time down into three components: input time,

decision time and motor time, with the decision time cor-

responding to Laming's (16) time spent in choosing a

response. In all choice reaction time studies and in the

present study, the decision time is the variable factor,

from trial to trial.

The design of the present experiment was identical in

most respects to the design of the majority of choice re-

action time studies with the major difference being the

length of the decision time. The results were in direct

conflict with previous results with the exception of the

difference in sex and the overall practice effect. Thus,

it is suggested that a complex-choice reaction time task

such as that used in the present study will not produce

results identical to simple and simple-choice reaction

time studies. Accordingly, the complex-choice reaction time

task does not appear to be classifiable into the same

category as all other reaction time studies.

CHAPTER BIBLIOGRAPHY

1. Andreas, B. G., Experimental Psychology, New York,John Wiley and Sons, Inc., 1972.

2. Behar, I., and C. K. Adams, "Some Properties of theReaction-Time Ready-Signal," American Journal ofPsychology, 79 (1966), 419-426.

3. Bergum, B. 0., and D. J. Lehr, "Monetary Incentivesand Vigilance," Journal of Experimental Psychology,67 (1964), 197-198.

4. Brebner, J., and I. Gordon, "The Influence of SignalProbability, and the Number of Non-Signal Categorieson Selective Response-Time," Quarterly Journal ofExperimental Psychology, 16 (1964), 56-60.

5. Brown, B. R., D. W. Walker, and S. H. Evans, "SchematicConcept Formation as a Function of ConstraintRedundancy and Knowl edge of Resul ts," Psychonomi cScience, 11 (1968)7, 5-76.

6. Church, R. M., and D. S. Camp, "Change in Reaction-Timeas a Function of Knowledge of Results," AmericanJournal of Psychology, 78 (1965), 102-106.

7. Emerson, P. L., "Simple Reaction Time with MarkovianEvolution of Gaussian Discriminal Processes,"Psychometrika, 35 (1970), 99-109.

8. Falmagne, J. C., "Stochastic Models for Choice ReactionTime with Applications to Experimental Results,"Journal of Mathematical Psychology, 2 (1965), 77-124.

9. Glasgow, J. M., and E. C. Jones, "Effects of Knowledgeof Results on Schematic Concept Formation withLinguaform Patterns," Psychonomic Science, 19(1970), 347.

10. Goodenough, F. L., "The Development of the ReactiveProcess from Early Childhood to Maturity," Journalof_ Experimental Psych oIoy 18 (1935), 431-450.

47

48

11. Hardesty, D., D. Trumbo, and W. Bevan, "Influence ofKnowledge of Results on Performance in a MonitoringTask," Perceptual and Motor Skills, 16 (1963),629-634.

12. Hodgkins, J., "Reaction Time and Speed of Movement inMales and Females of Various Ages," Research Quarterly,34 (1963), 335-343.

13. Hollier, J., and S. H. Evans, "Schematic ConceptFormation with Linguaform Patterns," PsychonomicScience, 9 (1967), 89-90.

14. Hyman, R., "Stimulus Information as a Determinant ofReaction Time," Journal of Experimental Psychology,45 (1953), 188-196.

15. Johanson, A. M., "Influence of Incentive and Punishmenton Reaction-Time," Archives of Psychology, 8 (1922),1-53.

16. Laming, D. R., Information Theory of Choice-ReactionTime, New York, Academic Press, 1968.

17. Lucaccini, L. F., A. Freedy, and J. Lyman, "MotivationalFactors in Vigilance: Effects of Instructions onPerformance in a Complex Vigilance Task," Perceptualand Motor Skills, 26 (1968), 783-786.

18. McCormack, P. D., F. R. S. Binding, and J. Chylinski,"Effects on Reaction Time of Knowledge of Results ofPerformance," Perceptual and Motor Skills, 14(1962), 367-372.

19. Merkel, J., "Die Zeitlichen Verhaltnisse derWillensthatigkett," Philosophical Studies, 32(1885),73-127. Cited by Woodworth, R. S., and H. Schlosberg,Experimental Psychology, New York, Holt, 1958.

20. Moss, S. M., "Changes in Preparatory Set as a Functionof Event and Time Uncertainty," Journal of ExperimentalPsychology, 80 (1969), 150-155.

21. Mowbray, G. A., and M. V. Rhoades, "On the Reduction ofChoice Reaction Times with Practice," QuarterlyJournal of Experimental Psychology, 11 (1959), 16-23.

22. Pearre, J. G., and E. C. Jones, "Effects of Knowledge ofResults on Schematic Concept Formation," PsychonomicScience, 12 (1968), 367-368.

49

23. Sipowicz, R. R., J. R. Ware, and R. A. Baker, "The Effectsof Reward and Knowledge of Results on the Performanceof a Simple Vigilance Task," Journal of ExperimentalPsychology, 64 (1962), 58-61.

24. Smith, R. L., L. F. Lucaccini, and M. H. Epstein,"Effects of Monetary Rewards and Punishments onVigilance Performance," Journal of AppliedPsychology, 51 (1967) , 411-416.

25. Sternberg, S., "Two Operations in Character Recognition:Some Evidence from Reaction-Time Measurements,"Perception and Psychophysics, 2 (1967), 45-53.

26. Stone, M., "Models for Choice-Reaction Time,"Psychometrika, 25 (1960), 251-260.

27. Teichner, W. H., "Recent Studies of Simple Reaction Time,"Psychological Bulletin, 51 (1954), 128-149.

28. , and M. J. Krebs, "Laws of VisualChoice Reaction Time," Psychological Review, 81(1974), 75-98.

29. Weidenfeller, E. W., R. A. Baker, and J. R. Ware, "TheEffects of Knowledge of Results (True and False) onVigilance Performance," Perceptual and Motor Skills,14 (1962), 211-215.

30. Woodworth, R. S., and H. Schlosberg, ExperimentalPsychology, New York, Holt, 1958.

CHAPTER V

SUMMARY AND CONCLUSIONS

The present study was designed to determine the relative

effects of monetary reward and knowledge of results of per-

formance on a complex-choice reaction time task. The investi-

gation covered twenty-six male and thirty-two female under-

graduate students enrolled at North Texas State University.

The mean age of the males .was 21.2 years and the mean age of

the females was 22.3 years.

The basic design was a three-dimensional analysis of

variance in which the three main factors and their respective

treatment categories were sex (male-female); motivation

(reward-knowledge of results-control); and, trial (twenty-one

individual or three blocks of seven each).

The complex-choice reaction time task consisted of a

visual choice reaction time apparatus that provided pre-

sentation of up to nine stimulus lights at any one time and

allowed independent selection of the eight response keys. Each

subject was presented twenty-one different trial problems in

identical sequence, with each of the seven possible responses

presented three times each. The subject was required to add

the number of lights presented, subtract that number from

a constant number and then press the correct answer on the

50

51

response key. The dependent variable consisted of the sub-

ject's reaction time to each of the twenty-one trials.

The reward condition subjects received twenty-five cents

for every response that was faster than a preestablished

criterion and twenty-five cents was deducted from their total

for every response slower than the same criterion. The know-

ledge of results of performance subjects were told their re-

action time after each trial. The control group received no

feedback at all.

The data obtained in this study appear to warrant the

following conclusions:

1. There were no significant differences between any

of the following motivational conditions: reward, knowledge of

results and control. A statistical analysis of the individual

subjects' reaction times yielded no significant differences

between any of the motivational conditions.

2. There was a significant overall practice effect in

this study. A statistical analysis of the subjects' reaction

times indicated that the subjects were reacting significantly

(.01 level) faster as the time on task increased.

3. There was a significant difference between sexes

with the reaction times for all motivational conditions

combined. A statistical analysis indicated that the males had

significantly (.01 level) faster mean reaction times than

the females.

52

4. A complex-choice reaction time study does not pro-

duce the typical results found in simple and simple-choice

reaction time studies. It should be emphasized that the re-

sults of this study indicate possible avenues for further

research in complex-choice reaction time experiments.

APPENDIX

TABLE VII

REWARD SUBJECTS' REACTION TIMES ON EACH TRIAL

Trial Subject3* 4* 5 6* 7 8 9 10*

1 2.46 1.87 1.64 1.99 2.33 3.90 1.20 2.80 1.95 4.862 2.60 1.47 1.64 1.57 2.07 2.48 1.04 9.64 1.37 2.063 3.96 2.83 2.23 1.80 2.54 2.67 1.24 6.05 1.74 2.214 2.03 1.71 2.01 2.34 1.79 4.48 3.06 2.20 2.36 5.805 1.35 2.25 4.14 7.07 4.61 9.99 1.53 7.55 4.54 3.466 1.34 1.77 1.29 1.85 2.06 2.18 1.24 2.22 1.71 2.677 1.09 1.25 1.60 1.30 1.51 1.70 1.11 1.73 1.33 1.858 1.39 5.99 5.01 2.50 2.70 2.99 1.25 4.09 1.21 2.509 0.86 1.62 1.10 6.40 1.54 2.97 1.18 1.77 1.65 2.1610 2.01 2.08 2.31 2.26 1.94 3.37 1.42 2.82 3.56 2.2211 1.36 1.25 1.05 1.71 1.44 1.18 0.87 1.52 1.27 1.5112 1.28 1.18 0.92 1.10 1.58 1.38 1.19 2.76 1.55 1.1513 1.28 1.94 1.16 1.22 1.51 1.78 1.05 9.99 1.55 1.7614 1.95 2.23 3.13 2.25 3.05 3.52 2.66 7.50 2.72 6.0715 1.38 1.86 4.76 1.98 2.69 2.57 1.47 2.01 4.81 4.0916 1.17 1.29 1.03 1.83 1.42 3.23 0.88 1.61 1.50 1.5617 2.20 1.48 3.01 1.73 2.07 2.11 1.33 3.66 2.09 2.7618 2.22 1.30 1.37 1.50 1.80 1.47 1.42 3.62 1.33 1.3819 0.79 1.26 0.91 1.18 1.25 1.44 0.96 1.94 1.15 1.5720 1.39 1.94 3.26 2.83 3.00 3.06 0.72 2.55 2.16 2.1521 2.49 1.31 1.22 1.37 1.86 2.11 1.28 1.75 1.53 1.64

*Female subjects.

53

54

TABLE VII --Continued

Trial Subject11 *2 _13*1 _ _4 -5 6 17* 18* 1

1 1.67 2.06 1.35 2.84 1.74 2.46 2.33 9.99 1.962 1.61 7.68 1.10 2.70 1.73 1.72 2.42 3.53 1.473 1.76 2.57 1.18 2.37 2.33 1.93 2.86 3.96 1.934 1.96 2.18 5.81 4.17 1.96 2.28 3.16 2.43 2.305 3.45 8.53 2.12 7.36 9.80 3.26 2.85 2.31 7.176 1.58 1.89 1.80 1.64 2.17 1.55 2.11 1.77 1.867 1.13 1.70 2.74 2.53 1.37 1.79 1.39 1.94 1.948 1.54 3.34 1.44 3.47 3.17 4.87 2.29 9.99 2.259 1.26 1.76 0.99 1.61 1.37 1.97 1.87 3.81 1.12

10 1.87 2.57 2.63 2.78 2.30 4.95 2.33 2.72 1.8711 1.24 1.44 1.04 1.12 1.58 1.24 2.24 2.06 1.2412 0.94 1.94 1.05 1.22 1.17 1.47 1.32 1.25 1.9013 1.18 1.77 1.31 1.99 1.19 4.32 1.56 2.16 1.3614 2.93 9.77 1.52 2.77 2.32 2.83 8.75 3.98 7.6415 9.69 2.16 1.72 3.91 2.44 2.44 2.65 2.90 1.9616 1.60 1.69 1.53 1.55 1.50 0.95 2.80 1.72 1.2817 1.91 2.18 3.02 2.15 1.97 3.07 7.01 9.99 2.7118 1.01 1.72 1.41 1.17 1.26 1.83 1.32 3.03 1.1219 2.38 1.61 0.92 1.11 1.53 1.77 2.48 1.52 1.2320 2.49 1.95 1.18 2.61 4.80 4.02 2.43 2.67 2.4121 1.48 4.31 1.06 4.81 2.59 1.43 2.36 5.87 1.43

55

TABLE VIII

KNOWLEDGE OF RESULTS SUBJECTS' REACTION TIMES ON EACH TRIAL

Trial Sube_1* 2131 4* J5-j 7* -i7-iw 10

123456789

101112131415161718192021

2.472.473.133.396.422.115.069.991.622.901.642.182.176.782.991.792.712.151.492.411.54

3.041.893.192.452.831.49!1.582.891.453.191.181.361.423.642.091.641.871.921.931.601.58

2.217.212.792.773.882.782.023.061.552.042.051 .341.252.132.391.432.021.521.326.771.72

1.729.992.011.969.991.762.267.351.681.891.231.621.452.212.831.552.021.301.393.161.63

2.271.611.662.713.011.471.361.221.142.090.920.890.942.002.020.811.231.010.910.991.57

2.842.132.962.926.421.861.713.621.292.711.201.311.582.732.591.522.491.641.169.991.671

1.521.171.671.942.261.221.979.991.401.490.911.071.061.941.881.004.491.161.332.501.301

2.962. 124.102.592.081.921.497.651.682.381.501.431.522.535.331.792.422.671 .225.181.70

5.751.595.002.955.051.811.302.401.912.442.341.331.572.372.171.972.091.591.181.531.431

*Female subjects.

2.111.585.922.732.111.821.362.051 .663.081.532.321.223.202.051.291.291.271.391.071.57

56

TABLE VIII --Continued

Trial Subject_ _ _ 12__ _1-3__ __14* 15 16* 17 18* 19 20

1 2.28 1.68 4.30 3.53 1.85 2.43 2.05 1.90 2.70 2.322 1.42 2.88 3.02 1.77 1.33 1.81 1.88 2.21 2.18 1.783 1.87 3.30 9.99 2.74 1.92 1.92 2.41 1.93 3.45 5.024 6.35 3.00 3.69 3.37 1.46 2.09 4.14 2.16 3.05 1.735 5.86 3.25 8.17 6.38 1.90 2.75 2.22 4.25 3.77 5.846 1.66 2.36 2.06 2.84 1.31 1.69 3.45 1.62 1.78 2.447 1.29 1.14 3.81 2.62 1.69 1.39 1.64 1.60 1.83 1.698 2.09 3.01 1.88 1.45 2.30 1.66 2.01 2.70 2.48 1.659 0.84 1.80 2.13 9.99 1.19 1.39 1.72 1.76 1.80 1.4210 3.02 3.25 3.32 5.20 1.19 1.99 2.16 2.36 1.69 2.0911 1.04 1.97 2.98 3.35 1.06 1.98 1.65 1.04 1.26 1.3612 1.13 1.52 2.35 1.53 1.05 0.99 1.27 1.59 1.53 1.1813 1.36 1.87 1.67 1.70 1.57 3.29 1.39 1.26 1.38 1.1814 1.69 4.10 2.83 2.85 0.92 6.92 4.08 1.95 4.10 0.9515 1.91 2.76 2.31 1.86 1.91 4.69 2.39 1.61 2.06 1.5016 1.07 1.98 2.18 1.96 0.95 1.47 2.04 1.90 1.80 1.6817 1.93 2.30 3.18 2.59 1.09 1.78 1.94 1.90 1.99 1.2118 1.02 1.92 2.48 5.66 1.10 1.21 1.69 1.29 1.20 1.1819 1.06 1.89 1.27 6.80 1.37 1.77 1.49 1.10 1.07 1.1720 1.76 1.98 2.11 3.64 1.30 1.44 2.93 2.90 1.91 1.4421 1.19 2.58 1.97 1.98 0.72 1.88 2.21 1.38 1.46 0.98

*Female subjects.

57

TABLE IX

CONTROL SUBJECTS' REACTION TIMES ON EACH TRIAL

Trial Subject1 2*13*1415* 6*17*8* 10

1.979.992.881.908.751.253.331.370.969.991.710.901.183.621.350.963.710.990.911.881.24

1.451.542.562.786.732.171.353.501.422.321.761.731.452.243.421.432.122.071.441.461.35

2.132.103.629.991.841.761.482.081.432.411.361.371.592.402.221.442.411.191.241.411.66

1.7611.7212.5612.5412.250.881.096.131.446.681.381.520.702.432.501.344.831.070.912.402.32

4I__ -__ __tI

*Female subjects.

1.862.592.112.754.631.651.302.631.241.831.241.332.749.993.131.191.831.281.233.701.35

3.792.021.711.919.991.131.333.391.233.060.761.051.041.472.250.741.641.290.921.001.03

2.351.642.832.591.307.342.031.711.442.381 .381.371.662.632.301.962.291.421.312.521.35

2.342.203.552.734.802.411.673.111.413.081.441.241.484.973.471.332.781.831 .402.081.95

2.351.921.562.672.291.371.331.271.161.581.051.051.150.965.861.221.131.260.961.461.49

IL -_ _ _ _..L . 1 1 -I .- -. -I1

123456789

101112131415161718192021

1.521.531.902.492.211.631.512.241.292.241.371.311.407.772.381.141.271.230.811.511.33

58

TABLE IX -- Continued

Trial Subject*12 3 4* 15* 16* 7 18 19

.123456789

101112131415161718192021

1,.90,1.832.413.093.443.132.043.882.521.932.18'1.431.872.292.181.832.571.731.712.012.10

3.241.842.602.052.911.481.652.571.322.572.201.200.972.163.381.072.531.3611.092.181.58

4.342.122.372.135.861.541.762.211.542.211.491.411.422.582.501.361.731.341.192.2612.141

7.332.202.742.651.922.502.132.131.562.121.461.511.642.501.711.352.081.421.312.371.49

2.441.343.502.091.542.081.312.072.811.811.371.0511.253.282.182.621.411.441.441.901.23

1.731.431.905.031.381.821.191.451.721.971.271.261.211.761.751 .731.331.361.371.401.43

2.491.761.601.682.571.49,1.2015.671 .401.841.041.071.102.053.081.231.951.461.151.961.20

5.472.071.722.675.543.121.831.712.212.735.231.351.622.482.29'2.492.221.322.013.161.47

2.881.432.144.272.060.891.422.151.261.841.221.471.362.522.661.284.021.421.551.451.68

- I- -

IIIf1

59

TABLE X

MEANS AND STANDARD DEVIATIONS OF MOTIVATIONAL CONDITIONAND TRIAL BLOCK REACTION TIMES

Motivational Statistic Trial Block Main Effect--Condition 1 2 3 Motivation

M 2.73 2.39 2.20 2.44Reward SD 0.84 0.80 0.63 0.78

N 19 19 19 57

M 2.82 2.24 2.00 2.35Knowledge SD 0.84 0.68 0.61 0.79

N 20 20 20 60

M 2.58 2.09 1.81 2.16Control SD 0.65 0.49 0.26 0.58

N 19 19 19 57

Main M 2.71 2.24 2.00 2.32Effect SD 0.77 0.67 0.55 0.73--Blocks N 58 58 58 174

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