The Basics of Experimentation:

Concepts, Definitions and Examples

The Debate: What is learned?

Behaviorists – (e.g., B.F. Sknner & Clark Hull) stimulus-response (S-R) associations; only observable behavior can be studied scientifically.

Cognitivists – (e.g., Ivan Pavlov & Edward Tolman) S-S associations, such as CS-US pairings or the relations among distal cues that form cognitive maps, can be inferred from observable behavior.

A process of elimination… Place units (cells) in the hippocampus respond to an animal’s location within the environment, not to a specific sensory stimulus, motor behavior or motivational incentive.

A Demonstration of Place Cell Firing

The activity of multiple hippocampal neurons (ensembles) during REM sleep matches the place activity of the same neurons when the animal was awake.

Are the animals dreaming of past places they have experienced?

Do rats and other mammals dream?

Some papers equate REM sleep with “dreaming sleep”One function of REM sleep may be to help consolidate memory of recent events

Experimental variablesEvery experimental variable has two

definitions:1) Conceptual – used in everyday

language2) Operational – used in conducting an

experiment.

Dreaming is conceptual and REM sleep is operational.

Experimental variablesHypotheses are often stated in

conceptual terms but experiments require operational definitions.

How will you operationally define variables in your study?

This is a critical step in setting up the Methods section.

Operational definitionsExperimental – what was done to

create the treatment conditions (IV).

Measured – What procedures were followed to assess the effect of the treatment (DV).

How do you define spatial learning, especially if it is possible that

animals may use a simpler form of stimulus-response (S-R) learning?

Measured operational definitions

Hypothetical ConstructsSpatial learning is a hypothetical

construct – an unseen process that is postulated to explain behavior.

The same construct variable can be

defined in different ways in different experiments.

Measured operational definitions

In the water maze study:Place response – escaping to the

hidden platform (S-S cognitive association).

Cue response – escaping to the visible platform (S-R association).

start

startCue Response

start

startPlace Response

Measured operational definitions

In a different Water maze study:A place response – visiting the old

location (spatial learning) before escaping to the visible platform (S-R learning) at a new location.

A cue response – not visiting the old location before escaping to the visible platform (S-R association).

start

startCue Response

start

startPlace Response

Measured operational definitions

In a Plus Maze study:Place response – Turning left or right at

the choice point depending the start location (spatial learning).

Turning response – Always turning left regardless of the start location (S-R association).

Measured operational definitions

Water maze:A place response – escaping to the

hidden platform (S-S cognitive association).

A cue response – escaping to the visible platform (S-R association).

Independent Variables (IV)What makes the IV “independent”?a) It is an aspect of the experiment

that varies.b) It is the dimension that the

experimenter manipulates.c) Its values are created by the

experimenter.d) Its values are not affected by

anything else that happens in the experiment.

Dependent Variables (DV)What makes the Dependent variable

“dependent”?a) It is an aspect of the experiment that

varies.b) It is the dimension that the experimenter

does not manipulate.c) It values depend on the effects of the IV.d) It is an objective measure of behavior

that is observed in the experiment.

Independent Variables (IV)What is the minimum number of levels

of the IV in any experiment?a) 0b) 1c) 2d) 3e) 4

Independent Variables (IV)Three kinds of IV (+ one more):1. Environmental variables (e.g.,

music)2. Task variables (hidden vs visible

platform)3. Subject variables (sex or personality

or learning strategy)4. Biological variables – (e.g.,

hormones, brain activation, drug effects)

What about this one? Pictures of babies increase oxytocin levels, which in turn…

Defining subject variables

Two room protocol

Would fast place learners in room A also be good latent learners in room B?

Results

Fast place learners = 2,3,4,6,9,10Good latent learners = 2,3,7,8,9,12

Inverse relation