Personality Correlates of Responses to Associative Mismatch and to Stimuli

Associated withReward or Punishment

Alan PickeringDepartment of Psychology

Collaborators

Patricia BradyInstitute of Psychiatry

James JeffsLuke Jones

St George’s Hospital Medical School

Outline

• Summarise Gray’s Reinforcement Sensitivity Theory (RST) of personality

• Note mixed results in existing literature

• Present new studies addressing basic issues from scratch

Reinforcement Sensitivity Theory

(RST)

• Bottom-up theory of fundamental personality dimensions

• Psychopharmacological and lesion studies in animals identify two basic systems

Basic Systems of RST

• Behavioural Inhibition System (BIS)

• Behavioural Activation System (BAS)

BIS Characteristics• Inputs: see next slide

• Outputs: inhibition and arousal

• Corresponding personality trait: anxiety

• Neural substrate: septo-hippocampal system

BIS Activating Inputs

• Aversive secondary reinforcers: i.e. conditioned stimuli associated with punishment or frustrative nonreward

• Novel stimuli: i.e. where an associative mismatch occurs

• Innate fear stimuli

BAS Characteristics• Inputs: see next slide

• Outputs: arousal

• Corresponding personality trait: impulsivity (sensation seeking)

• Neural substrate: dopaminergic projection systems

BAS Activating Inputs

• Appetitive secondary reinforcers: i.e. conditioned stimuli associated with reward or relieving nonpunishment

Existing Studies

• Extensive literature since 1970

• Several reviews (e.g., Pickering et al, 1997)

• Usually significant results

• Conflicts across studies

Typical Experiment

1. Take healthy volunteers

2. Measure their trait anxiety and/or impulsivity

3. Expose to BIS and/or BAS activating stimuli

4. Measure behavioural effects of 3 and correlate with scores from 2

Confusing Findings

• Effects of “wrong” personality trait• Unexpected direction of correlations• Variations of traits that correlate• Nature of reinforcers used varies• Unrealistic/complex reinforcers used• Misunderstanding of theory by other

researchers• Some parts of theory untested• Unexpected effects of gender

New Studies 1

• Associative mismatch stimuli

• Stimuli associated with ecologically valid punishments (EVPs)

• Verbal instructions warning of EVPs

Investigated behavioural effects and personality correlates of the following:

New Studies 2

• Additivity of effects

• Associated neural activations via fMRI

Other issues explored were:

Basic Paradigm

• Choice reaction time (RT) task

• Warning stimuli manipulated to create BIS and BAS inputs

• Key stimuli presented to Ss incidentally while doing choice RT

Standard Trial Sequence

+

A

AssociativeMismatch Sequence

+

L

SecondaryReinforcer Sequence

+

A

Choice RTTask Measures

Mean RT and % errors on:

critical trials (associative mismatch or secondary reinforcer)

compared with

immediately preceding standard trials

BIS (Trait Anxiety) Questionnaires

• Eysenck’s Neuroticism Scale: EPQ-N

• Spielberger’s State-Trait Anxiety Inventory: STAI-Y2

• Cloninger’s Harm Avoidance Scale: HA

• Carver and White’s BIS Scale: BIS

Study One: Overview

• Investigated effects of Associative Mismatch (AM)

• 30 healthy volunteers (M/F)• Trait anxiety measures used: STAI-

Y2; BIS; HA• 140 choice RT trials (1-40

practice), including 12 AM trials

Study One: Correlations

RT Difference (AM – Standard)

Measure Corr. p-valueY2 -0.30 0.1HA -0.14 nsBIS -0.35 0.06Comb. -0.32 0.09

Study One: AM RTs By Anxiety Median Splits

0.375

0.38

0.385

0.39

0.395

0.4

0.405

Lo-ANX Hi-ANX

AM

Standard

Study Two: Overview• Investigated effects of AM and secondary

reinforcers (SRs), both aversive and appetitive

• 40 healthy volunteers (male medical students)

• Used preconditioning procedure to create secondary reinforcers

• 350 choice RT trials (1-50 practice), including 6 AM and 24 SR trials

Study Two: Questionnaires

• Trait anxiety measures used: STAI-Y2; BIS; HA; EPQ-N

• A range of measures of BAS-related traits (impulsive sensation seeking)

Study Two: BAS Questionnaires

• Eysenck’s Extraversion and Psychoticism Scales: EPQ-E/P

• Eysenck’s Impulsiveness Scale: I7-IMP• Cloninger’s Novelty Seeking Scale: NS• Carver and White’s BAS Scale: BAS• Introvertive Anhedonia: IAN

Study Two: Preconditioning

• Fully counterbalanced design

• Associates 4 neutral geometric symbols (A-D) with reinforcing events

• Subject immerses hand in ice-water for “unknown period” (actually 45 secs)

• Subject watches award of “random prize” in 50 pence units (actually £3.50)

Study Two: Preconditioning Symbols

Occurs … Associated Reinforcement

A 7 times in first 35 secs cold water immersion

Punishment (Pun)

B twice to signal last 10 secs of cold water

Pun or Relieving Non-Pun (RNP)

C 7 times signalling 50 pence reward each time

Reward (Rew)

D twice to signal end of reward sequence

Frustrative Non-Reward (FNR)

Study Two: Overall RTs

0.32

0.33

0.34

0.35

0.36

0.37

0.38

0.39

0.4

0.41

AM Pun Sym-B Rew FNR

CritComp

Study Two: AM & BIS Correlations I

RT Difference (AM – Comparison)

Measure Corr.p-valueY2 -0.05 nsEPQ-N -0.04 nsHA -0.28 0.08BIS -0.23 nsHA+BIS -0.28 0.08Comb. -0.18 ns

Study Two: AM & BIS Correlations II

RT Difference (Rew – Comparison)

Measure Corr.p-valueY2 -0.04 nsEPQ-N -0.11 nsHA -0.20 nsBIS -0.30 0.06HA+BIS -0.27 0.09Comb. -0.19 ns

Study Two: Rew Regression Results

• DV= RT Diff (Rew – comparison)• Ist Block: Anxiety (HA+BIS)• 2nd Block: BAS traits

Final model:DV= K – 0.35*Anx – 0.32*EPQ-E

Study Two: Pun & BIS Correlations

RT Difference (Sym-B – Comparison)

Measure Corr.p-valueY2 0.28 0.08EPQ-N 0.35 0.03HA 0.14 nsBIS 0.42 0.008HA+BIS 0.31 0.06Comb. 0.36 0.02

Study Two: Pun RTs By Anxiety Median Splits

0.31

0.32

0.33

0.34

0.35

0.36

0.37

0.38

0.39

0.4

Lo-ANX Hi-ANX

Sym-B

Comp

Conclusions• Anxiety is related more strongly to the

arousal, than to the inhibition, produced by associative mismatch (AM)

• Anxiety is related more strongly to the inhibition, than to the arousal, produced by secondary reinforcers associated with punishment (SR-Pun)

• The anxiety measures correlating with AM and SR-Pun effects may differ

Conclusions (continued)• The arousal effect, produced by

secondary reinforcers associated with reward (SR-Rew), is:

associated with extraversion-impulsivity measures

additive to the arousal effect produced by AM