“I Want It Now!” Neural Correlates of Impulsive Decisions and Actions
“I want it now!” Four monosyllabic words that neatly describe the motivations of younger generations, driven by a heightened sense of entitlement and disregard for the potential future consequences of their actions (Twenge, 2006; Twenge & Campbell, 2009); the very hallmarks of impulsivity. The aim of the present research was to investigate the neural and behavioural correlates associated with the instance at which an impulsive decision for action is made, and the related constructs of motor inhibition and conflict resolution. A specific aim was to inform how these are reflected in the neural networks of executive control and attention; building from a framework for the allocation of focused attention for action (Franz, 2012). Novel, purpose-developed Delay of Gratification and Go/No-go tasks were employed with concurrent electroencephalography, along with psychometrically established impulsivity personality questionnaires. The experimental tasks formed the basis of two experimental studies, with supplementary information provided by the questionnaires. Study 1 (Delay of Gratification) employed a computerised method to test impulsive choices during manipulated conflicts via presented stimuli, delay periods, and outcome consequences; methods that are novel in the context of existing research using hypothetical situations. The importance of an actual delay period was implicated in the key findings that Delayers produced a larger fronto- central P2 component than Non-Delayers, and upon choice of immediate gratification Non- Delayers did not exhibit error negativity or positivity components. Together with other specific findings, these results suggested that maladaptive focused attentional control enabled impulsive choices to be made without evidence that participants actually experienced feelings of erroneous responding. Study 2 (Go/No-go) investigated the impulsive actions by probing more rudimentary processes of impulsivity using a modified Go-No-go task that was uncomplicated by emotional conflict. The key cognitive processes under investigation included response choice selection and action inhibition/execution. It was found that concurrent presentation of competing actions (i.e., incongruent action-effects perceptual codes) impaired speed of responding when action execution was required, and increased demand for motor inhibition (as reflected by the production of larger No-go P3 component) when action restraint/inhibition was required. These findings, and other specific results, highlight the importance of executive control and allocation of attention in the successful inhibition or facilitation of responding. Of primary importance, this research provides support consistent with the view that at the moment of impulsive behaviour, focused attention is allocated in favour of an impulsive action plan due to reprioritisation of goals and motivations. This results in the release of inhibitory control and the pursuit of the impulsive outcome.
Advisor: Franz, Elizabeth; Linscott, Richard
Degree Name: Doctor of Philosophy
Degree Discipline: Department of Psychology
Publisher: University of Otago
Keywords: Psychology; Neuropsychology; Impulsivity; EEG; ERPs; Delay of Gratification; Go/No-go; Action Inhibition; Decision Making
Research Type: Thesis