C82MPR – Practical Methods 2

Dr Mark Haselgrove

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Recapitulation

Blocking (Kamin, 1968)

Group Stage 1 Stage 2 Test

Blocking A → US AX → US X =cr

Control - AX → US X = CR

- Surprise is necessary for learning to take place.

- Quantified by Rescorla & Wagner (1972): what you get – what you expect

- Unblocking: Increase/decrease in US strength after AX trials

But,

- Unblocking is Sometimes seen with a qualitative change in US after AX

Blocking or no blocking.....WHY ?

Betts Brandon & Wagner (1996)

Stage 1 Stage 2 Test

A→US1 AX→US2 X

U1

U2

C

R1

RC

R2

AA

XX

Associations entered into by A

Association entered into by X

Will be weak upon testing X

Will be STRONGupon testing X

This Practical…

The effect of changing the US on blocking in human participants

Literature Search: Use Google Scholar

In Google scholar, conduct a search:

Search terms: blockingunblocking

blocking OR unblocking AND Learningblocking OR unblocking AND Conditioningblocking unblocking AND human AND conditioning

Poor search terms alone:too general

This Practical…

The effect of changing the US on blocking in human participants

Getting the paper:

This Practical…

The effect of changing the US on blocking in human participants

This Practical…

The effect of changing the US on blocking in human participants

This Practical…

Ensure that :

You are running either Windows XP or 7 (not Mac OS)

You have a folder on the C: drive called temp

If you don’t do either of these the task will not work

Goto:

http://www.psychology.nottingham.ac.uk/staff/mxh/C82MPR/Week2

and download a file called Task.exe

The Task

- Participants adopt the role of a Health and Safety Inspector

- Presented with (fictitious) hospital patients who have become ill after eating certain meals.

Meals = CSs

Illness = US

- Participants have to rate how dangerous the meals are on a 1-9 scale

The Task: Design

Stage 1 Stage 2 Test

A → US1

B → US2

C → noUS

DE → US1

FG → US2

HI → noUS

AX → US1

BY → US1

CZ → US1

FG → US2

HI → noUS

X

Y

Z

Trials in italics are filler trials

The Task: Details

- Food types (e.g. chicken, apple) randomised as A, B, C for each participant

- Vomiting and Diarrhoea randomised as US1 and US2 for each participant

- 10 trials with each type in Stage 1 5 trials with each type in Stage 2 1 presentation of each stimulus during the Test

- Trial order randomised in each stage

- Location (top/bottom) of food type randomised on each trial

The Task: Data

- Stored automatically to C:\temp

- File called “participant number ”.csv (e.g.: 31.csv)

- Double click to open in Microsoft Excel

Homework

- Get into groups of about 5 or 6 and run a total of about 30 participants

- Discuss how you will run the experiment (at home, laptop, in dept?)- Consider debriefing Participants (give feedback on goals of experiment)- Be wary of overwriting data if using same PC

General References

- Bouton (2007) Good background to learning. Hardback, so expensive

Pearce (2008) Excellent general introduction to learning theory and blocking