Clarifying the subtypes of impulsivity and their cognitive and behavioural underpinnings

Caswell, Amy J (2013) Clarifying the subtypes of impulsivity and their cognitive and behavioural underpinnings. Doctoral thesis (PhD), University of Sussex.

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Investigators have suggested impulsivity consists of several behavioural subtypes including ‘reflection’- (decision-making without evaluation of information), ‘temporal’- (failure to delay gratification) and ‘motor’- (failure to inhibit a motor response) impulsivity. These facets of impulsivity are thought to be dissociable, but to share some common underlying processes.

The current studies investigated such processes. Study 1 investigated speed and accuracy biases, using instructions and cognitive priming to challenge impulsivity. Study 2 & 3 challenged inhibitory control resources, via a dual task and alcohol challenge, to investigate the effect on impulsivity. Study 3 also investigated the effect of alcohol outcome expectancies on impulsivity.

The factor structure of impulsivity was also investigated using exploratory factor analysis (study 4), to establish whether the primary measures of the proposed subtypes can indeed be categorised into these three factors. Study 4 also investigated the relationship of participant demographics to impulsivity.

The studies support the suggestion of a distinct subtype of reflection-impulsivity. Inhibitory control processes do not appear to underlie performance, however biases in speed/accuracy trade-offs have implications for this subtype.

Behavioural inhibitory control was found to be the primary process underlying motor-impulsivity whilst biases for speed/accuracy have implications for Go-responses. The factor analysis provided preliminary evidence that there may be two distinct facets of motor-impulsivity: action cancellation and action restraint.

Inhibitory control processes were not found to underlie temporal-impulsivity on an experiential task. Biases for speed/accuracy were found to contribute to performance on pen-and-paper measures. However, subsequent factor analysis provided evidence that experiential tasks may actually be more closely related to a form of cognitive control, instead of temporal-impulsivity.

In conclusion, the studies found that the three proposed factors of impulsivity differentially rely on inhibitory control processes and biases for speed/accuracy. However, factor analysis indicated that additional factors may be required to fully characterise impulsivity.

Item Type: Thesis (Doctoral)
Schools and Departments: School of Psychology > Psychology
Subjects: B Philosophy. Psychology. Religion > BF Psychology > BF0199 Behaviourism. Neobehaviourism. Behavioural psychology
Depositing User: Library Cataloguing
Date Deposited: 20 Nov 2013 08:47
Last Modified: 17 Sep 2015 12:26

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