REMOTE EXPERIMENTAL CYBERNETIC ANALYSIS OF DEIAYED FEEDBACK OF ORAL BREATH PRESSURE CONTROL I N NORMAL AND EMPHYSEMA PATIENTS: APPLICATION TO SPACE MEDICINE

Karl U. Smith, Professor of Psychology, Universi ty of Wisconsin, Madison, Wisconsin John P. Henry, Direc tor of Research, Veterans

Administration Center, White River Junction, Vermont Richard K. Junas, Indus t r i a l Relat ions Dept., Ladish Corporation, Milwaukee, Wisc. Sherman D. Ansell , Project Supervisor, Universi ty of Wisconsin, Madison, Wisconsin

This f i r s t remotely cont ro l led experimental cybernetic study of behavior had two object ives: t o test t h e p o s s i b i l i t y of carrying on two-way communication between a computer system and ex- perimental subjec ts i n order t o conduct var iable- feedback research on r e sp i r a to ry pa t i en t s , and t o probe t h e methodological problems of delayed- feedback research i n space science. of ex erimental feedback analys is (Smith & Smith,

with a hybrid computer f p t e m (Smith, Ansell , Koehler & Servos, 1964 ) (Smith, 1965 9, t o measure t h e e f f e c t s of variable- feedback delays on o r a l breath-pressure cont ro l i n normal and emphy- sema pa t i en t s , who were located i n a hosp i t a l some 150 m i l e s d i s t a n t from the computer system which w a s used t o manipulate t he feedback var iables .

The methods

1962 E 2) (Smith, 1962 lo) were used i n conjunction

The p o s s i b i l i t y of u t i l i z i n g a cent ra l ized computer t o study behavioral and physiological

-processes of remotely located subjec ts has been recognized f o r some t i m e i n medical, i ndus t r i a l , space, and educational science. However, system- a t i c experimentation has awaited the development of t heo re t i ca l concepts concerning feedback con- t r o l i n closed-loop human systems as w e l l as appropriate laboratory techniques. I n t h i s re- search, w e not only suggest a broad theory def in- ing t h e r a t i ona l e and objec t ives of experimental behavioral cybernetics but a l s o explore methods of our own design which can serve as the bas is of instrumentation i n t h i s f i e l d .

This study of delayed feedback i n t he respi- ra tory pa t ien t is one phase of t he experimental cybernetic _analysis of t i m e f ac to r s i n physiologi- c a l systems. Feedback delay can be defined as a transmission lag i n any p a r t of t h e closed-loop pathways t h a t govern ac t ion i n organic systems. Our research is based on t h e cybernetic view t h a t the functions of a l iv ing organism represent s e l f - regulated cont ro l processes which must be under- stood and analyzed i n terms of t h e real-time var- i ab l e s of feedback cont ro l . These var iables de- f i n e t he k i n e t i c s of response of t h e organic system under both normal and extreme condit ions. We study delayed feedback by interposing a computer- control led delay between somatic response and some sensory e f f e c t produced by t h e response. I n t h e present research, t h i s general method is used t o study reac t ions of normal and emphysema pa t i en t s t o delayed v i sua l feedback of i n t r a o r a l breath- pressure cont ro l .

Although t h i s s tudy tests a spec i f i c hypoth- esis about delayed feedback i n respi ra tory d i s - ease, our la rger a i m is t o evaluate a more general t heo re t i ca l problem of feedback cont ro l i n biology and medicine. Hotwithstanding t h e f ac t t ha t phys- iology and medical science have accepted t h e con- cept of cybernetics (Wiener, 1948 15> (Grodins and James, 1963 4), t h i s acceptance has not modified conventional homeostatic models of physiology and bra in fucs t ion except t o couch them i n t h e

terminology of information o r sampled-data theory with i ts l imited statements of behavioral and physiological cont ro l , and cannot predic t what w i l l happen when the feedback loop of an organic system is perturbed by delay, s p a t i a l d isp lace- ment o r transformation, va r i ab l e time in ter rup- t i ons , k i n e t i c t ransformations, o r varying modes of pos i t i ve and negative feedback cont ro l . De- layed feedback experiments provide examples of t h e operat ion of real- t ime feedback var iables i n closed-loop physiological systems as contrasted t o abs t r ac t informational proper t ies . A s con- t r a s t e d t o t h e homeostatic concept of t h e l i v ing animal, which w a s accepted by Wiener (1948), t h e present research and the design of i ts computer methods have been guided by what w e c a l l a homeo- k i n e t i c view. We assume t h a t a l l rhythmic and periodic operat ions of t h e l i v ing body have t h e i r bas ic cycles determined by the demands f o r closed- loop regula t ion of s t a r t i n g f r i c t i o n i n molecular and c e l l u l a r systems, and hence of t h e s e n s i t i v i t y and synchronism of receptor and nerve c e l l s of these systems. This means t h a t t h e primary bas i s of physiological regula t ion starts wi th real- t ime cybernetic con t ro l of energy exchange i n t h e cyc l i c a c t i v i t i e s r e l a t ed t o spontaneous c e l l u l a r rhythms, tremor, bra in rhythms, hea r t pulse, r e sp i r a to ry rhythm, nystagmus, inner ear noise, stomach contract ions, u t e r ine a c t i v i t y and men- s t r u a l cycle. The view is t h a t one aspect of t he feedback cont ro l of these primary rhythms is the demand f o r t h e i r integrated synchronous cont ro l by the b ra in and f o r in tegra ted regula t ion of var- i a t i o n i n each of them fordynamic a c t i o n of t he s k e l e t a l m t o r system. This approach implies t h a t one approach t o analys is of physiological regula- t i o n and motivation is the measurement of t h e real-time fac to r s involved i n t h e i n t e r ac t ion between the regula t ion of s k e l e t a l muscle and the r a t e and synchronism of t he body's rhythmic functions. Observation of the e f f e c t s of de- layed feedback is one of t he most promising experimental cybernetic approaches of t he s o r t . W e bel ieve t h a t t h e study of delayed feedback eventually w i l l provide evidence about the mechanisms of se l f- regula ted synchronism of body rhythms, about t he r o l e of neural fac tors i n t h e i r temporal in tegra t ion , and about t h e externa l somatic cont ro l of va r i a t i ons i n these rhythms. Methods

The research combines new methods of using a hybrid closed-loop computer system f o r va r i ab l e feedback experiments on i n t r a o r a l breath cont ro l (Henry, Junas & Smith, 1965 6, and of t ransmi t t ing t h e computer-controlled s igna l s by commercial telephone l i ne s t o e f f e c t remote cont ro l of v i sua l feedback of breath regula t ion in pa t i en t s . A diagram of t he experimental operat ion is given i n Figure 1. The subject w a s located in a research f a c i l i t y i n t he Respiratory Section of Hines Mem- o r i a l Hospital , Chicago. H e attempted t o maintain constant i n t r a o r a l breath pressure on a mouth tube by watching a v i sua l osc i l loscopic d isp lay which

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i nd i ca t ed v a r i a t i o n s . A Sanborn Respirometer transduced t h e brea th pressure v a r i a t i o n s i n t h e mouth t o analog e l e c t r i c a l s i gna l s which w e r e t ransmi t ted by analog dataphone t o t h e Behavioral Cybernetics labora tory of t he Universi ty of W i s - consin a t Madison. H e r e t h e hybrid computer sys- t e m converted t h e breath s i g n a l to d i g i t a l form, programed i t f o r feedback de lay , measured it and accumulated on- l ine t h e experimental measurements f o r d a t a ana ly s i s . Af te r t h e computer manipula- t i o n , t h e feedback s i g n a l of brea th pressure w a s deconverted t o analog form and s en t back over a second telephone l i n e t o a c t i v a t e t h e osc i l loscop- i c d i sp l ay f o r t h e subjec t i n Chicago. The com- puter monitored a l l d e t a i l s of t h e experiment, such as running c a l i b r a t i o n s on t h e system p r i o r t o each t r i a l , warning t h e sub j ec t of c a l i b r a t i o n periods and t h e beginning and ending of each t r ia l , and timing and scheduling t r i a l s and experimental condi t ions . The setup provides a complete model of computer-controlled closed- loop opera t ion f o r e i t h e r medical o r d iagnos t ic research .

Subject S t a t i o n

Figure 2 i l l u s t r a t e s t h e t ransducing s t a t i o n i n Hines Memorial Hospital , where t h e sub j ec t attempted t o maintain constant b rea th pressure on t h e small mouthpiece of a tube . The t a sk w a s not un l ike blowing a s m a l l horn with constant b rea th pressure , except t h a t it i s monitored by a v i s u a l feedback d isp lay r a t h e r than by sound. The sub- j e c t watched t h e t a r g e t spo t on t h e sc reen of a Tektronix Osci l loscope and t r i e d t o keep it on a zero i nd i ca to r l i n e . The v a r i a t i o n s i n pressure t h a t w e r e r e l a t e d t o t h e s u b j e c t ' s movements and phys io logica l processes were transduced t o analog s i g n a l s by means of a Sanborn Respirometer, t h e vo l tage output o f which w a s made compatible with t h e dataphone l i n k t o Madison. shown by t h e s u b j e c t ' s r i g h t a r m .

The dataphones are

The o sc i l l o scop i c spot viewed by t h e sub j ec t represented h i s b rea th pressure v a r i a t i o n s f a i t h - f u l l y . The only v a r i a t i o n introduced by t h e com- pu t e r system i n Madison w a s a temporal de lay . That is, t h e sub j ec t s a w t h e e f f e c t s o f h i s per- formance a f t e r a con t ro l l ed de lay i n t e r v a l .

The sub j ec t ' s performance during t h e experi- ment was recorded on an o sc i l l og raph i n t h e com- pu t e r l abora tory . This record provided an i nd i - ca t i on of t h e accuracy of t h e c a l i b r a t i o n and measurement procedures used, and a l s o gave an immediate i nd i ca t i on of sub j ec t performance t o t h e experimenters i n Madison.

Design of Conversion Processes

The hybrid computer system i l l u s t r a t e d i n Figure 1 has been designed t o a c c o m d a t e a l a r g e v a r i e t y of input and output analog d a t a sources which are conventional ly used i n recording and i n s t imulus con t ro l i n physiology. The system w i l l accept any analog input between 0 and 5,000 cps, sample it a t a predetermined sampling rate from 0 t o I0,OOO sps , program feedback v a r i a t i o n s i n t h e d i g i t i z e d s i gna l , deconvert t h e va r i ed signal. back t o analog form, and then u se t h e output s i g n a l t o a c t i v a t e some v i s u a l , audi tory , or cutaneous feed- back d i sp l ay t o the sub j ec t . t h e se procedures t o a n experiment which involved s p a t i a l s epa r a t i on of t h e input- d isp lay s t a t i o n

The ex tens ion of

from t h e computer-control l abora tory posed only rou t i ne t e chn i ca l problems once t h e da t a l i n e s between Madison and Chicago were i n s t a l l e d .

Computer Procedures

A s shown i n Figure 3, t he computer c a r r i ed ou t a number of experimental opera t ions accord- ing t o i ts programed i n s t ruc t i ons . The ba s i c experimental procedure of introducing a de lay i n t o t h e feedback c i r c u i t is conceptual ized i n Figure 3 as a process of wr i t i ng i n and reading out s i gna l s i n t h e c y c l i c a l memory core of t h e computer. I n such a memory cycle, t h e length of t h e de lay i n t e r v a l is determined by t h e d i s t ance separa t ing t h e po in t a t which a s i g n a l is wr i t t en i n and t h e point a t which it is read out .

The computer a l s o monitored t h e experimental t r ials, as ind ica ted by t h e record shown i n Fig- u r e 3. The tremor-like v a r i a t i o n s recorded i n t h i s one-minute t r i a l represen t t h e brea th con- t r o l movements of a demonstration sub j ec t . The four marks a t t h e beginning of t h e record are s i g n a l s generated by t he computer before each t r ia l . The f i r s t mark warns t he subjec t t h a t a c a l i b r a t i o n on t h e system is t o be run and t ha t he should no t touch t h e mouth tube. In t h e i n t e r- v a l between t h e second and t h i r d marks, a zero c a l i b r a t i o n of t h e system i s es tab l i shed . The subjec t then g e t s set f o r a t r i a l and the fourth mark warns him t h a t it is about t o begin. The mark a t t h e end of t he t r i a l t e l l s t h e subjec t t h a t t h e t r i a l has ended.

The Control Data Corporation 160-A computer used i n t h e presen t system is a buffered c i r c u i t which can be used simultaneously t o con t ro l output and t o analyze d a t a on- l ine . b rea th- cont ro l s i g n a l w a s measured i n magnitude 128 t i m e s pe r second by t h e computer and t h e mean of t he se measures w a s ca lcu la ted every h a l f sec- ond f o r paper t ape and typewr i te r readout . i l l u s t r a t e d a t t h e bottom of Figure 3, t h e r e s u l t - ing d a t a shee ts contained t he se half-second means arranged i n rows of t en means each, with twelve such rows t o a t r i a l . The t r i a l and experiment numbers w e r e i d e n t i f i e d f o r each row. Punched tapes of such tabula ted d a t a were used t o convert t h e experimental d a t a t o card form i n order t o c a r ry ou t t h e f i n a l da t a ana ly s i s on a l a r g e r com- pu t e r .

- Cal ib r a t i on Accuracy

The d i g i t i z e d

As

The computer system is designed t o provide f o r complete c a l i b r a t i o n of a l l i ts conversion and transducing s e c t o r s and t o make poss ib le t ransfer- func t ion c a l i b r a t i o n of input r e l a t i v e t o t h e output feedback d isp lay . Figure 4 i l l u s t r a t e s t h e f i d e l i t y of t h e conversion process by sompar- ing an input o s c i l l a t o r s i g n a l wi th t he d i g i t i z e & output of t h e computer. The p l a t e i l l u s t r e t e s a wave of approximately 4 cps sampled a t about 2 2 sps , a wave of 266 cps sampled a t about lOQQ sps and a wave of 750 cps sampled a t 5Q00 sps.

I n order t o e s t a b t i s h c a l i b r a t i o n of a t rans- duced behavioral o r p h y s i o h g i s a l input r e l a t i v e t o v a r i a t i o n i n t h e p rope r t i e s of t b e Feedbtek disp lay , two types of programs have been developed- In t h i s s tudy, t h e computer w a s programed to re- cei-ve s i g n a l s from a zero s e t t i n g of the transducer

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and a feedback indicator and t o es tabl ish the voltage corresponding t o these readings as zero. The computer then measured the magnitude of var- ia t ions from t h i s zero cal ibra t ion. In other studies, the computer may be programed t o receive voltage values representing successive movement posit ions of the input transducer as re la ted t o corresponding posit ions o r loc i on the feedback display and t o compute the t r ans fe r function re- la t ing movement posit ion and display loci . From t h i s a cal ibra t ion t ab le is computed and used by the computer i n e r ro r measurement.

Experimental Design

Twenty subjects were used i n the experiment, ten normal individuals who were members of the hospi ta l sec re ta r i a l and c i v i l service s t a f f , and ten emphysema pat ients . j e c t s w a s divided in to two comparable t ra ining groups, one ofwhichwas trained i n the breath con- t r o l t a sk with a feedback delay of 0.0 second, and the other ofwhichwas trained with a feedback delay of 3.2 seconds. That is, half of the normal and half of the pat ient group trained with no de- lay and half trained with a delay of 3.2 seconds. Each subject received 1 2 t ra in ing tr ials of 24 seconds each, which were separated by rest in te r- vals of 30 seconds each. The t ra ining session had t o be kept short because o f t he condition of the pat ients . Following the t ra ining t r ia ls , each subject w a s given ten test tr ials with delayed feedback, each t r i a l with a di f ferent magnitude of feedback delay. The ten di f ferent delay in te r- vals used were 0.0, 0.1, 0.2, 0.3, 0 . 4 , 0.7, 1.0, 2.0, 2.5, and 3.2 seconds. The order of presenta- t i o n w a s randomized by subject , with the s a m e ten randomly selected orders used for both the normal and pat ient groups.

Each group of ten sub-

Magnitude of er ror i n maintaining constant o r a l breath pressure was measured as the dependent variable. In addition, the visual record made possible the comparison of frequency and pat tern of response i n the normal and pat ient groups under the di f ferent conditions of delayed feedback dur- ing t ra ining and i n the delay tests.

The monitoring of t h i s experiment required an investigator a t the subject s t a t ion i n Chicago and two technical a s s i s t an t s i n Madison. Comunica- t ion w a s achieved over the l ines which w e r e used t o carry data. The f i r s t s t ep i n se t t ing up the experiment consisted i n establishing compatibility between the respirometer voltages and the ampli- f i e r input in to the computer system. Other than t h i s problem and some i n i t i a l minor problems with noise i n the data l ines , the procedures of the experiment quickly w e r e reduced t o routine opera- t ions *

Results

The data from the t ra ining and t e s t ing phases of the study consist of v isual records of the subjects ' performances,graphical summaries of the e r ro r data, and analyses of variance of differences re la ted t o subject groups, delay conditions i n training, practice, and delay magnitude i n the delay tests -

I n analyzing the data, it w a s found tha t complete performance breakdown resul t ing i n ex- t r e m e posi t ive o r negztive pressure on the input

transducer produced a d r i f t i n the voltage level that violated the computer ca l ibra t ion and re- corded unreal scores fo r these par t icular trials.. In such cases, it w a s necessary t o make corrections by assigning e r ro r values appropriate t o the level of performance e r ro r . Records of tr ials contain- ing frequent instances of breakdown performance w e r e scored by using a transparent overlay, marked t o conform t o the computer ca l ibra t ion and with computed deviations i n transducer pressure.

Training Records

Figures 5, 6 , 7 and 8 sumarize the records of a l l twenty subjects during t ra ining, presenting respectively re su l t s of the normal nondelay group, the normal delay group, the pat ient nondelay group, and the patient delay group. The records for a l l twelve t ra ining tr ials are given i n order for each subject of each group.

Figure 5 shows that a l l subjects but one of the normal nondelay t ra ining group displayed a consistent degree of control over breath pressure, although the pattern and frequency of movements d i f fered great ly i n the f ive subjects. It should be noted tha t the records for Subject 2 were ob- tained at half the speed of the other records. Subject 5 displayed a much higher frequency of movements than the f i r s t three subjects. 3 and Subject 5 w e r e the most accurate. 1, 3, and 5 showed a marked learning e f fec t through- out t ra in ing. e f fec t u n t i l the 11th t r ial , when he became highly inaccurate and unstable.

Subject Subjects

Subject 4 showed a marked learning

The t ra ining records for the normal delay group i n Figure 6 show re la t ive ly random behavior fo r the mast pa r t . attempted t o control t h e i r breath pressure by generating high speed variations i n t h e i r movements. Subject 5 a lso t r i e d t h i s t r i c k on occasion. There is no evidence of learning i n these f ive subjects other than t h e i r use of these high speed movements.

Subjects 3 and 4 of t h i s group

The records of the f ive pat ients with non- delay t ra ining are given i n Figure 7 . Notice tha t the records of the f i r s t patient of t h i s group w e r e obtained a t half-speed. Although the records from the f i r s t three pat ients showed nearly random performance, pat ients 4 and 5 of t h i s group were nearly as accurate as the normal subjects. Pat ients 3, 4, and 5 gave c lea r evidence of learn- ing.

The records from the patient delay group i n Figure 8 show tha t the performance of pat ients with delayed feedback w a s even more haphazard than t h a t of normal subjects under the s a m e condition. Two of the pat ients t r i e d the technique of generat- ing rapid movements for short periods of t ime,tut fo r the most par t , a l l f i v e pat ients seemed com- ple te ly los t under the delay conditions. is no evidence of learning i n the records.

Quantitative Variations i n Learning

There

The resu l t s of graphical and quant i ta t ive analyses of the effects of the di f ferent experi- mental variables during the t ra ining se r i e s can be discussed re la t ive t o differences a t t r ibu tab le to t ra ining conditions (delay and nondelay), t o subject groups, and to variations i n performance within t r i a l periods.

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Delay v s Nondelay Training: Figure 9 i l l u s - trates t h e d i f fe rences i n t r a i n i n g performance r e l a t e d t o t h e de lay and nondelay condit ions. The curves represen t mean e r r o r o f combined p a t i e n t and normal groups p l o t t e d as a func t ion of t r ia l s . N o cons i s t en t l ea rn ing e f f e c t w a s found wi th t h e 3.2 seconds delayed feedback condi t ion . Training with nondelayed feedback produced l imi ted learn- ing over t h e twelve tr ials but performance w a s i r r e g u l a r . The l eve l of e r r o r f o r t he de lay groups w a s two t o t h r e e t i m e s as g r ea t as t h e l e v e l f o r t h e nondelay groups.

9 .

Pa t i en t v s Normal Performance: Figure 10 def ines graphica l ly t h e s i g n i f i c a n t i n t e r ac t i ons between subjec t condi t ion , t r a i n i n g condi t ion , and learn ing during t r a i n i n g . This graph p l o t s mean e r r o r as a funct ion o f tr ials f o r each of t h e t r a i n i n g groups s epa ra t e ly . This graph shows, as d id Figure 9 , a marked d i f f e r ence i n l e v e l of performance r e l a t e d t o t r a i n i n g condi t ion , and a l s o shows a marked d i f f e r ence i n l e v e l of per- formance between pa t i en t and normal groups. of t he i r r e g u l a r i t y i n performance wi th t h e non- delay condi t ion w a s cont r ibu ted by t h e p a t i e n t group, which had an e r r o r l e v e l almost double t h a t of normal sub j ec t s w i th nondelayed feedback. However, t h e p a t i e n t s and normal sub j ec t s who t r a i ned with delayed feedback showed approximately t he same learn ing change.

Kuch

Change i n Performance During T r i a l Periods: The successive measures of performance obtained during each t r i a l made it pos s ib l e t o compare groups r e l a t i v e t o performance v a r i a b i l i t y w i th in trials. Figure 11 makes t h i s comparison between normal sub j ec t s and p a t i e n t s and a l s o between de lay and nondelay t r a i n i n g groups. t h e l e f t shows t h a t e r r o r i n both normal and pa- t i e n t groups w a s h ighes t at t h e beginning of t h e t r ia ls and then dropped o f f . normal sub j ec t s continued t o dec l i ne throughout tr ials, but e r r o r l eve l f o r t h e p a t i e n t s increased a t t h e end of t h e t r i a l . The graph t o t h e r i g h t i n Figure 11 ind i ca t e s t h a t t h i s f i n a l rise a l s o w a s r e l a t e d t o t he delayed feedback t r a i n i n g con- d i t i o n . Thus w e i n f e r t h a t t h i s increase i n e r r o r l e v e l i n t h e f i n a l period of t h e t r i a l w a s due t o the performance of t h e p a t i e n t de lay group. This graph a l s o shows much mre i n t r a t r i a l v a r i a t i o n during nondelay t r a i n i n g than during de lay t r a i n - ing. reduced t h e i r e r r o r l e v e l by about 40 percent from t h e f i r s t t o t h e second period of t h e t r i a l .

Quant i ta t ive Analyses of Differences i n Training Data: A summary of t h e ana ly s i s of var iance of t h e t r a i n i n g da t a is given i n Table 1. A l l c r i t i c a l sources of v a r i a t i o n except t h e con- d i t i o n of sub j ec t s (A) were s i g n i f i c a n t at t h e 5 percent level. The d i f f e r ences due t o sub j ec t condit ion approached s i gn i f i c ance . When normals and p a t i e n t s are considered only i n r e l a t i o n t o nondelay t r a i n i n g , t h e d i f f e r ence between t he se two groups is s t a t i s t i c a l l y s i g n i f i c a n t . This p o s s i b i l i t y is suggested by t h e s i g n i f i c a n t i n t e r - ac t i on between sub j ec t condi t ion and t r a i n i n g condi t ion . are s t a t i s t i c a l l y S ign i f i c an t at t h e 5 percent l eve l . s i g n i f i c a n t F value.

The graph t o

E r ro r l e v e l f o r t h e

Subjects t r a i n i n g wi th nondelayed feedback

The learn ing e f f e c t s previously noted

Variance due t o per iods also produces a

Results of Duncan Range Tests (Duncan, K ~ 5 5 ) ~ shown i n Figure 12 summarize t h e s i gn i f i c ance of d i f f e r ences between means f o r a l l learn ing t r i a l s computed f o r a l l p a t i e n t s and a l l normal sub j ec t s , and f o r de lay and nondelay t r a i n i n g groups. t h e t a b l e t o t h e l e f t , t h e letters "D" and "0" r e f e r r e spec t i ve ly t o t h e groups who t r a i ned with a 3.2 second de lay , and t h e groups who t r a i n e d with t h e zero delay. I n t h e t a b l e t o t he r i g h t "P" and "B' r e f e r t o p a t i e n t and normal, B a r s overlapping any two means given i n t h e t h i r d col- umn of each t a b l e i n d i c a t e t h a t t h e overlapped means are not s i g n i f i c a n t l y d i f f e r e n t from one another a t t h e 5 percent l e v e l . The middle column of each t a b l e i d e n t i f i e s t h e number of t he t r i a l f o r which t he se means were computed. i nd i ca t e t h a t systematic d i f f e r ences occurred not only between sub j ec t condi t ions and t r a i n i n g con- d i t i o n s , as noted above, but a l s o between learn ing trials. The bar lengths i nd i ca t e t h e degree of d i f f e r e n t i a t i o n due t o learn ing f o r t h e d i f f e r e n t condi t ions . P a t i e n t s displayed somewhat more def- i n i t e l ea rn ing change than d id t h e normal sub j ec t s . The many invers ions of t r i a l order f o r t he de lay t r a i n i n g condi t ion i nd i ca t e s t h a t l ea rn ing with delayed feedback w a s f a r from systematic .

E f f ec t s o f Magnitude of Delayed Feedback '

I n t h e second p a r t o f t h e experiment, a l l

I n

These t a b l e s

sub j ec t s were t e s t e d with t e n d i f f e r e n t magnitudes of delayed feedback varying from 0.0 t o 3.2 sec- onds. Performance under each of t h e s e test con- d i t i o n s w a s analyzed r e l a t i v e t o t r a i n i n g condition,

Var ia t ion i n Normal Subject Performance as a Function of Delay Magnitude: Figures 13 and 14 g ive t h e performance records of t h e t e n normal sub j ec t s i n responding wi th d i f f e r e n t magnitudes of delayed feedback. Figure 13 g ives t he records f o r sub j ec t s who were t r a i ned with no de lay , while Figure 14 g ives records f o r sub j ec t s t r a i ned with 3.2 second delay. The numbers bes ide t h e records represen t de lay magnitudes used i n t h e tests . By reading down t h e series of records f o r each sub- ject , one can determine t h e de lay va lue a t which performance con t ro l w a s impaired o r broke down. For example, t h e f i v e sub j ec t s i n Figure 13 showed impairment a t 0.2, 0.7, 0.3-0.4, 0.1, and 0 .1 sec- onds r e spec t i ve ly . For t h e sub j ec t s i n Figure 14 who had been t r a i ned with 3.2 seconds de lay , ser- ious impairment occurred a t 0.2, 0 .7 , 0.4-0.5, 0.0, and 0.120.4 second. The main e f f e c t of increas ing t h e magnitude of de lay w a s t h e g ro s s and sometimes progress ive d e t e r i o r a t i o n i n t h e p a t t e r n of re- sponse. Increase i n de lay magnitude usua l ly caused a systematic reduc t ion i n t h e dominant response frequency except i n those ins tances when a subjec t s t a r t e d genera t ing high-frequency movements. Pro- g re s s ive changes are seen i n a l l sub j ec t s o f t he nondelay t r a i n i n g group and i n a l l but Subject 4 of t h e de l ay t r a i n i n g group.

Spec i f i c t r a i n i n g w i th delayed feedback had l i t t l e o r no e f f e c t on performance i n t h e test series. Subjec ts i n t h e de lay t r a i n i n g group gen- e r a l l y d i d no b e t t e r a t t h e d i f f e r e n t test delays t han d i d t h e sub j ec t s o f t h e nondelay t r a i n i n g group. This w a s t o be expected inasmuch as l i t t l e i f any learn ing occurred dur ing t r a i n i n g w i th de- layed feedback,

Performance of t h e p a t i e n t groups i n t h e test series is i l l u s t r a t e d by t h e records i n Figures 15 and 16, which were obtained r e spec t i ve ly from the p a t i e n t s who were trained. without de lay and those

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who w e r e t r a i ned wi th delay. The lat ter group showed almost completely disorganized behavior during t h e tests with varying magnitudes of feed- back delay, whereas some of t h e nondelay t r a i n i n g group w e r e ab l e t o r e ac t t o a few of t h e varying delay magnitudes i n t h e test series. This w a s t r u e p a r t i c u l a r l y of Pa t i en t s 1, 3 and 4 i n Fig- u r e 15. Pa t i en t s 2 and 3 of t h i s group generated very rap id brea th movements i n t h e attempt t o maintain con t ro l of t h e i r movements.

Delay Functions: Figure 17 p l o t s mean e r r o r of a l l twenty subjec ts as a funct ion of de lay magnitude. The curve is nega t ive ly acce le ra ted , showing severe d i s turbance of performance w i t h a 0.2 second de lay and leve l ing of f a t de lay magni- tudes of 0.7 t o 1.0 second. The func t ion appears q u i t e regular and none of t h e measured po in t s f a l l s very f a r from t h e smoothed curve.

Delay funct ions f o r t r a i n i n g condi t ions and f o r pa t i en t and normal subjec t groups are given i n Figure 18. There are no marked d i f f e r ences i n t h e funct ions f o r t h e de lay and nondelay t r a i n i n g groups, but curves f o r normal sub j ec t s and pa t i en t s are widely separated f o r de lay magnitudes below 2.0 seconds. of 0.1 and 0.2 second is almost double t h a t o f normal sub j ec t s .

Er ror l e v e l of p a t i e n t s with delays

When delay funct ions are p lo t t ed s epa ra t e ly f o r t he four experimental groups, it i s seen t h a t t he main d i f fe rences are r e l a t e d t o t h e d i f f e r - ences i n subjec t condi t ion a t delays lower than 2.0 seconds. show marked va r i a t i ons r e l a t e d t o t h e t r a i n i n g condit ion.

Neither p a t i e n t s nor normal sub j ec t s

I n t h e test series, l e v e l of e r r o r i n suc- cess ive periods wi th in tr ials w a s g r e a t e s t at t h e beginning of t h e t r i a l and decreased t h e r e a f t e r . The decrease from t h e f i r s t t o the last period w a s approximately 12 percent . There w e r e no not- ab l e d i f f w e n c e s between normal and p a t i e n t groups i n i n t r a t r i a l v a r i a t i o n i n t h e test series.

Quan t i t a t i ve Analyses of Differences i n Tes t - Data: Table 2 summarizes t h e analyses of var iance of t h e test da ta . As ind ica ted by t h e A and B terms i n t h e summary t a b l e , n e i t h e r subjec t con- d i t i o n nor mode of t r a i n i n g gave s i g n i f i c a n t d i f - ferences i n response i n t h e delayed feedback tests. Differences due t o delay magnitude w e r e s i g n i f i - cant a t t h e 1 percent l eve l , as w a s t h e i n t e r - ac t i on between sub j ec t condi t ion and de lay , and t r a i n i n g condi t ion and de lay . -

Figure 19 summarizes t h e s i g n i f i c a n t varia- t i o n s i n means f o r de lay magnitudes f o r both pa- t i e n t sub jec t groups, and f o r de lay t r a i n i n g groups. The des igna t ions f o r pat ient . and normal sub j ec t s are IlP" and "N" i n t h e l e f t t a b l e , while those f o r de lay and nondelay t r a i n i n g groups are "D" and "N" i n t h e r i g h t t a b l e . Any overlapping of c o m n means by a s i n g l e bar s i g n i f i e d t h a t t he se means are no t s i g n i f i c a n t l y d i f f e r e n t from one another . Intermixture of letters des igna t ing p a r t i c u l a r experimental groups i n a given t a b l e i nd i ca t e s t h a t t h e groups do not show s i g n i f i c a n t d i f f e r ences from one another i n a given range of means. The concentrat ion of means represen t ing t h e normal 5ubjec ts a t t h e low l e v e l s of e r r o r in t h e left t a b l e suggests t h a t at t h e low delay

magnitudes normal sub j ec t s d i f f e r e d s i g n i f i c a n t - l y from p a t i e n t s .

Figure 20 summarizes t h e s i gn i f i c ance of d i f - ferences between e r r o r means f o r a l l twenty sub- jects a t t he d i f f e r e n t de lay magnitudes. The v e r t i c a l ba r s a t t h e r i g h t i nd i ca t e means t h a t are not s i g n i f i c a n t l y d i f f e r e n t a t t h e 45 percent level. Breaks occur between de lay magnitudes of 0.1 and 0.2 second, 0.4 and 0.7 second, 1.0 and 2.5 sec- onds, and 2.0 and 3.2 seconds. The only i nve r- s i o n i n order i n t h e series of means w a s t h a t found f o r those r e l a t e d t o de lay values of 2.0 and 2.5 seconds. Variation in feedback de lay magnitude produced cons is ten t changes i n behavior, even i n t h e r e l a t i v e l y uncontrol led behavior of p a t i e n t s .

Discussion

This research d e a l t with t he e f f e c t s o f de- layed feedback on t he learn ing and performance of i n t r a o r a l breath-pressure c o n t r o l i n normal sub- jects and emphysema p a t i e n t s . A prime ob j ec t i ve of t h e research w a s t o develop and eva lua te methods of using a remotely located hybrid computer system t o monitor and con t ro l v a r i a b l e feedback experi- ments on phys io logica l and behavioral funct ions. The success fu l completion of t h e experiment sub- s t a n t i a t e d our expec ta t ions t h a t a hybrid computer system can be used t o c a r r y ou t feedback analyses on sub j ec t s located a t any poin t on e a r t h with which dataphone l i nks can be es tab l i shed . By spec i fy ing t h e e s s e n t i a l f e a tu r e s of hybrid com- pu t e r design needed t o conduct remotely cont ro l led behavioral and phys io logica l research , t h i s s tudy de f i ne s a means of applying labora tory closed- loop computer techniques t o behavioral and medical research i n space sc ience .

Sumary of Findings

The main f ind ings of t he t r a i n i n g phase of t h i s research are: (1) t h a t systematic t r a i n i n g of p a t i e n t s and normal sub j ec t s can bb cont ro l led by a closed- loop computer f a c i l i t y located a t a d i s t ance from t h e subjec t s t a t i o n ; (2) t h a t s i g- n i f i c a n t l e a rn ing of o r a l b rea th- pressure con t ro l occurs with nondelayed v i s u a l feedback; (3) t h a t p a t i e n t s with r e s p i r a t o r y disease d i f f e r s i g n i f i - can t l y from normal sub j ec t s i n accuracy of o r a l breath-pressure con t ro l ; (4) t h a t t h e learn ing change i n p a t i e n t s equals t h a t found with normal sub j ec t s even though t h e e r r o r l e v e l of t he pa- t i e n t s w a s s i g n i f i c a n t l y h igher ; (5) t h a t both normal sub j ec t s and p a t i e n t s show severe d i s t u rb- ances i n o r a l b rea th- pressure con t ro l when sub- j ec t ed t o delayed v i s u a l feedback; (6 ) t h a t no learn ing occurs during t r a i n i n s with feedback de- l ays of 3.2 seconds; (7 ) t h a t t h e i n t r a t r i a l v a r i a b i l i t y of p a t i e n t s w a s s i g n i f i c a n t l y g r ea t e r than t h a t of normal sub j ec t s .

The main f ind ings of t h e series of tests u t i l i z i n g d i f f e r e n t magnitudes of feedback delay are: (1) t h a t performance e r r o r i n both normal and p a t i e n t sub j ec t s increases wi th increas ing de lay magnitudes i n a nega t ive ly acce le ra ted func- t i o n ; (2) t h a t normal sub j ec t s and p a t i e n t s vary s i g n i f i c a n t l y i n accuracy with feedback de lay below 2.0 seconds; (3) t h a t t r a i n i n g w i t h feedback delays of 3.2 seconds d i d no t improve t h e accuracy of e i t h e r normal o r p a t i e n t sub j ec t s i n performing wi th de lay masnitudes between 0.5 and 3.2 seconds;

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(4) t h a t t h e p a t t e r n of o r a l b rea th- cont ro l move- ments v a r i e s with increases i n de lay magnitude, showing decreased movement frequency and decreased i n t e g r a t i v e cont ro l ; (5) t h a t both normal and pa- t i e n t sub j ec t s sometimes genera te f a s t b rea th ing movements i n at tempting t o maintain breath- p ressure con t ro l wi th feedback de lays exceeding 1.0 second.

The r e s u l t s o f t h i s research extend our p r i o r experimental cyberne t ic analyses of r e s p i r a t i o n (Henr?, Becktel , Sharp, Smith, and Eagle, August 1964 ) and of o r a l breath-pressure con t ro l wi th delayed feedback (Henry, Junas, and Smith, Sub- mi t ted 6, some ways than those of our f i r S t experiment on t h e s a m e problem i n def in ing t h e learn ing and feedback de lay func t ions of o r a l b rea th- pressure con t ro l .

The presen t f ind ings are clearer i n

Our only s p e c i f i c hypothesis i n t h i s s tudy regarding t h e emphysema p a t i e n t s w a s t h a t t h e i r d i s ea se . cond i t i on would c o n s t i t u t e a source of phys io logica l pe r t u rba t i on of t h e brea th- cont ro l movements. We a t t r i b u t e t h e l imi ted a b i l i t y of emphysema p a t i e n t s t o respond t o t h e delayed feed- back not t o some hidden de lay i n t h e neu ra l feed- back c i r c u i t s underlying r e s p i r a t i o n , bu t r a t h e r t o t h e per turb ing e f f e c t s of d i s turbed brea th ing on a more r e f i ned l e v e l of movement con t ro l i n t h e r e sp i r a to ry system. The p a t i e n t s observed had a l imi ted a b i l i t y t o achieve normal r e s p i r a t i o n , and t h i s d i f f i c u l t y w a s r e f l e c t e d i n t h e i r very poor performance relative t o normal sub j ec t s with feed- back delays of lower magnitudes.

Re la t ion t o Space Medicine and Physiology

The m a x i m u m delay i n t e r v a l s used i n t h i s ex- periment are comparable t o t h e feedback de lays which w i l l be encountered i n any attempt t o es tab- l i s h earth-based monitoring of behaviora l and phys io logica l systems of men located on t h e moon o r on moon satellites. Our f ind ing t h a t no learn- ing o r adapta t ion occurs i n o r a l b rea th con t ro l wi th feedback delays of t he se magnitudes i nd i ca t e s t h a t any e f f o r t t o e s t a b l i s h earth-based con t ro l of a c t i v i t i e s on t h e moon w i l l encounter a l l t h e d i f f i c u l t i e s and gross behaviora l d e f i c i e n c i e s found wi th t he experimental de lays .

The experiment described he r e de f i ne s cJur conception of t h e app l i c a t i on of experimental cyberne t ics t o space medicine, monitoring of as t ronaut physiology, and environmental con t ro l of remote cosmic systems i n r e l a t i o n t o as t ronaut behavior and adapta t ion . This approach d i f f e r s from o the r concepts of phys io logica l ana l space systems (Tol les and Cyjberry, 1959 “f; in (Specht and Dropkin, 1956 ) , (Lincoln and Mangels- do r f , 1965 *) i n t h a t w e design experimental sys- t e m s t o analyze behavioral and phys io logica l con t ro l in . te rms of real-time va r i ab l e s of t h e closed- loop feedback c i r c u i t s . We be l ieve t h a t research i n space medicine and human physiology i n cosmic systems must be based on procedures of dynamic closed- loop ana ly s i s of t h e feedback- con t ro l mechanisms. The behavior and physiology of men i n space must be analyzed i n real t i m e r e l a t i v e t o a c t u a l events i n space and in t h e ob- se rva t i on and recording s t a t i o n s on ea r t h .

Behavioral Feedback Factors i n Phys io logica l Control

This research has defined a rev ised t heo re t - ica l approach t o somatic con t ro l of body rhythms, such as r e sp i r a t i on , which emphasizes t h e i r homeo- k i n e t i c p rope r t i e s as a n a l t e r n a t i v e t o t h e con- cept of homeostasis (Cannon, 1934 l) (Wiener, 1948). Our view is t h a t a bas ic property of the skeletal-muscle neuromotor system is t o gener- ate continuous a c t i v i t y which w i l l f a c i l i t a t e molecular mechanisms of receptor , nerve, and muscle, and i n t e g r a t e t h e r e sp i r a to ry process with o the r dynamic rhythms of t h e body. of this experiment support t h i s cyberne t ic i n t e r - p r e t a t i o n of r e sp i r a to ry con t ro l by showing t h a t t h e p a t t e r n and dynamics o f response i n both pa- t i e n t s and normal sub j ec t s are changed dramatically by changes i n temporal r e l a t i onsh ip s of t h e feed- back con t ro l loop. These r e s u l t s , t h e r e fo r e , suggest t h a t t heo r i e s such as t he sampled-data models of t h e r e s p i r a t o r z system (Defares, 1962 2 ) , b rodins and James, 1963 ) , (Melhorn and Guyton, 1964 7), which e l imina te cons idera t ion of real- t i m e feedback f a c t o r s i n spec i fy ing o v e r a l l a c t i on of a phys io logica l system, introduce mathematical uncer ta in ty propor t iona l t o t he feedback de lays which are ignored and cannot descr ibe the va r i ab l e course of bodily a c t i v i t i e s e i t h e r i n hea l th o r i n d i sease . c r i p t i o n of v a r i a b l e feedback con t ro l of o r a l b rea th pressure and presumably of t h e o ther re- sponse c h a r a c t e r i s t i c s of t h e r e sp i r a to ry system.

The da t a showing t h a t t h e dynamic p a t t e r n of

The r e s u l t s

A cyberne t ic view is essential f o r des-

brea th con t ro l changes sys temat ica l ly with t h e magnitude of feedback de lay confirms our view t h a t t h e experimental ana ly s i s of va r i ab l e feed- back de lay i n phys io logica l response cons t i t u t e s a new way of i nves t i ga t i ng t h e k i n e t i c s of primary organic rhythms. The rhythmic o r per iod ic move- ments of t h e body depend on real-time s igna l ing , and any v a r i a t i o n i n t h e temporal c h a r a c t e r i s t i c s of t h e c losed c i r c u i t s o f t h e sensori-neuromotor system leads no t only t o changes i n t h e form of t h e response but a l s o t o s h i f t s i n t h e i r c y c l i c c h a r a c t e r i s t i c s .

The presen t research may have pointed impli- ca t i ons f o r a new type of experimental- theoret ical approach t o r e h a b i l i t a t i o n and medical handling of t h e r e sp i r a to ry p a t i e n t . and r e s u l t s of t h i s s tudy de f i ne poss ib le f a c to r s i n learn ing and t r a i n ing , which may be used i n con t ro l of normal and impaired r e sp i r a t i on . Spe- c i f i c a l l y , w e have found t h a t t h e capac i ty f o r l ea rn ing of c e r t a i n l eve l s of b rea th con t ro l i n r e s p i r a t o r y d i s turbance , as i n emphysema, may be impaired by t he genera l phys io logica l per turba t ion of r egu l a t i on of somatic movements which is asso- c i a t e d wi th t h e d i sease . One o v e r a l l e f f e c t o f t h e r e sp i r a to ry d i so rde r is t o introduce dynamic per turba t ions i n sensorimotor i n t eg ra t i on which i n e f f e c t act much i n t h e same way as delayed feedback i n de l imi t ing p o t e n t i a l level of learning at any l e v e l of t h e r e sp i r a to ry system. cep ts o f homeokinetic real-time regula t ion of r e s p i r a t i o n and assoc ia ted methods of experimental feedback ana ly s i s of b rea th con t ro l may i n t i m e g ive us add i t i ona l c lues about t h e l i m i t a t i o n of r e l e a rn ing of new methods of breathing and tech- niques of r e t r a i n i n g in t h e r e sp i r a to ry p a t i e n t .

The theory, methods

The con-

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Furthermore, the laboratory feedback methods of research described here constitute an entirely new spectrum of rehabilitative training pro- cedures for persons afflicted with different kinds of respiratory disease.

References

1. Cannon, W. B., Handbook of General Ex- perimental Psychology (Clark University Press, Worcester, Mass., 1934) Hunger and Thirst.

chemostat with accessible parameters,'' Ann. NY. Acad. Sci. 96, 1956-61 (1962).

3 . Duncsn, D. B. "Multiple range and multiple F tests," Biometrics 11, 1-42 (1955).

4. Grodins, F. S . and James, G., "Math- ematical models of respiratory regulation," Ann. N.Y. Acad. Sci., 109, 852-68, (1963).

5. Henry, J. P., Becktel, J., Sharp, J.T., Smith, K.U., and Eagle, E., "Cyclical components of ventilatory flow in eupneic respiration," Physiologist, 7 , 1958, (1964).

6. Henry, J. P., Junas, R., and Smith, K.U., "Experimental cybernetic analysis of delayed feedback of breath-pressure control," (Submitted).

"Mathematical models of human respiratory control systems," Fed. Proc., 23, 307, (1964).

"An integrated approach to evaluating the per- formance capabilities and physiological state of spacecraft crews. Company, Sunnyvale, California, 1965).

Behavior (Academic Press, New York, 1965) Cyber- netic theory and analysis of learning. (In Press)

10. Smith, K. U., Delayed Sensory Feedback and Behavior, (Saunders, Philadelphia, Pa., 1962).

11. Smith, K. U., Ansell, S. D., Koehler, J., and Servos, G. H., "Digital computer system for dynamic analysis of speech and sound feedback mechanisms," J. Assn. Comptg. Machinery, 11,

2. Defares, J. G., "A model of respiratory

7 . Melhorn, H. T . , Jr., and Guyton, A.C.,

8. Lincoln, R. S., and Mangelsdorf, J. E.,

(Lockheed Missiles and Space

9. Smith, K. U., Motor Learning and Motor

240-251, (1964). 12. Smith, K. U., and Smith, W. M., Percep-

tion and Motion: An Analysis of Space-Structured Behavior, (Saunders, Philadelphia, Pa., 1962).

medical data compression," Proceedings of the National Telemetering Conference, Houston,(l965).

system for monitoring the electrocardiogram dur- ing body movement," USAF WADC Tech. Rep. 58-453, (1959).

York, N.Y., 1948).

13 . Specht, D. F . and Dropkin, T. W., "Bio-

14. Tolles, W. E., and Carberry, W. J., "A

15. Wiener, N. Cybernetics. (Wiley, New

Table 1. ANALYSIS OF VARIANCE SUMMARY TABLE. FOR TRAINING DATA - LINE SOURCE DF Ms TERM F

A

B

C

D

E

F

G

H

I

3

K

L

M

N

0

P

9

R

S

Conditions

Training Groups

Cond. x Tr. Gps.

Subjectslgroups

Trials

Periods

cond. x Tr.

Cond. x Per.

Tr. Gps. x Tr.

Tr. Gps. x Per.

Tr. x Per.

Cond. x Tr. Gps. x Tr.

Tr. Gps. x Tr. x Per.

Tr. x Per. x Cond.

Per. L Cond. x Tr. Gp8.

Cond. x Tr. Gps. x TI. x Per.

Subjlgr. x Tr.

Subjlgr. x Per.

Subjlgr. x Tr. x Per.

Total

1

1

1

16

11

3

11

3

11

3

33

11

33

33

3

33

176

48

528

959

-

13462.52 D

423990.23 D

35392.95 D

5826.91 S

295.49 S

5501.92 S

273.89 S

389.40 S

654.08 S

803.22 S

109.04 S

393.38 S

106.58 S

131.07 S

536.49 S

81.78 S

543.00 S

365.91 S

114.79

2.31

72.76*

6.07**

50.76*

2.57*

47.93*

2.39*

3.39*

5.7w

6.99*

.95

3.43*

.93

1.14

4.67*

.71

4.?3*

3.18*

* Significant at the 1% level Significant at the 5% level

Table 2. ANALYSIS OF VARIANCE SUM4AF.Y TABU. FOR DELAY TEST DATA

ERROR LIrn SOURCe DF Ms TERM P

A

B

C

D

E

F

G

H

I

3

K

L

M

N

0

P

Q R

S

Conditions

Training Groups

Cond. x PI. Gps . SubjectslGroupe

Delay*

Periods

Cond. x Del.

Cond. x Per.

Tr. Gps. x Del.

Tr. Gps. x Per.

Del. x Per.

Cond. x Tr. Gps. x Del.

Tr. Gps. x D e l . x Per.

Del. x Per. x Cond.

Per. x Cod. x Tr. Gps.

Cond. x Tr. Gps. x Del. x Per.

Subjlgr. x Del.

Subjlgr. x Per.

Subjlgr. x Del. x Per.

Total

1

1

1

16

9

3

9

3

9

3

27

9

27

27

3

27

144

48

432

799

-

29743.60 D

2352.97 D

95 2 2 D

7398.69 S

11765.51 S

9007.81 S

1559,74 S

292.68 S

655.08 S

681.32 S

284.58 S

2087 .Oh S

139.61 S

200.19 S

262.71 S

113.05 S

904.04 S

197.01 S

151.91

4.02

.32

.01

48.70*

77.45*

59.29*

10.26*

1.92

4.31*

4.48*

1.87*

13.74*

.92

1.32

1.73

.74

5.95*

1.29

- * Significant at the 1% level

-332-

4 N l 2 . 5 CPS

266w/1000 CPS

750W/5OOC CPS

FIGWE 3.

-333-

FIGURE 4.

i-

iil Y - \-

12-

FIGURE 5 . FIGURE 6 .

PATIENT 0.0 TFNNIN: PATIENT 3.2 TRAINING

1- 1- 1-

r! k-

1-

s

F I W 7. FIGWE 8

-334-

TFNNING GROUPS X TRIALS

51.37

50.55

45.62

48.50

CONDITIONS X TRAlNING GROUPS X TRIALS

Mean Error --

*. 3 I 3.2 Seconds Delay

0.0 Seconds Delsy

I T

0 2 4 6 10 12

Trial Number

FIGWX 9.

0 1 2 3 4 ?aria& limber

Me- Error

60-

50-

40 -

30-

20 - -

17 Normal

Period Nmhcr

i’IGtiW 11.

*‘Patient - 3.2 -.

2ot - Normal - 0.0

l l l ~ ! ~ ! ~ ~ ~ ~ ~ 0 2 6 R 10 12

Trial Number

FiGlmE 10.

TRAINING ORDER WEAN

D

D

D

D

D

D

D

D

D

D

D

D

U

0

0

0

0

0

0

0

0

0

0

3

9

3

7

11

2

12

8

10

4

5

6

1

6

3

1

2

4

8

5

9

11

7

12

10

72.00

70.75

70.75

70.55

65.25

65.10

68.12

66.62

64.87

64.12

64.07

62.95

31.87

25.85

29.65

28.22

26.72

26.37

25.02

24.32

24.07

21.30

21.12

20.25

SUBJECT ORDER KBAN

P

P

P

P

P

P

P

P

P

P

N

P

N

P

7

N

3

6

2

4

11

1

8

9

12

7

9

5

3

10

7

2

8

11

5

12

10

6

1

47.62

46.70

46.37

45.55

45.20

44.42

43.95

43.95

43.22

42.77

41.72

41.67

41.57

4L.52

4 38.97

FIGLRE 12

-335-

PIGLRE 14.

PATIENT E I A Y

0.0-

- : LL -

0.1--

FKGURi: 16.

-336-

I I I I 1 0.5 1.0 1.5 2.0 2.5 3.0

BELAY HAGNlTVOE

GROUP DEWY IEANS

P 3.2 73.37

N 3.2 68.37

P 2.0 67.00

P 1.0 66.75

N 2.0 66.37

N 2.5 65.37

P 0.7 64.75

P 2.5 64.25

P 0.2 60.37

P 0.4 57.12

P 0.3 53.45

N 1.0 52.50

N 0.7 51.15

P 0.1 47.87

I

I P 0.0 44.50

N 0.4 44.12

N 0.3 42.00

X 0.2 32.82

N 0.1 27.87

x 0.0 26.30

FIGURE 17.

I

' i

TRAINING GROUP DEIAY MEAN

0 3.2 74.871

0 2.0 69.75

D 2.5 68.75

D 3.2 66.87 1 1 1 D 2.0 63.62

0 2.5 60.87

0 0.7 59.87

D 1.0 57.37

D 0.7 56.62

0 0.3 53.20

0 0.4 51.62

0 0.2 50.75

D 0.4 49.62

D 0.2 42.45

D 0.3 42.25 I

a 1.0 61.87

'I D 0.1 39.87

0 '0.0 36.92

0 5.1 35.87

B 0.0 33.87

I

0 , 1 0 1 1 I I I I I I a 0.5 1.0 1.5 2.0 2.5 3.0 '

DELAY M I N a CSECaW)

ORDER - 1

2

3

4

5

6

7 "

8

9

10

F I G W 18.

DEIAY -

6.0

3.1

0.2

0 .3

VIA

0.7

1.0

2.5

2.0

3.2

MFAN

37.87 35.40* I 40 60

77.72

50.02

58.25

59.62

66.68

70.67 I

* 5 pereent level

FlGUKE 20

-337-