Do High-risk Prisoners Entering Treatment Have Clinically Impaired Cognitive Impulse Control?

Abstract

Moffitt's (1993) developmental theory suggests that offenders on the life-course persistent (LCP) trajectory inherit or acquire neuropsychological deficits that compromise impulse control, and ultimately contribute to criminality. Empirical tests of this notion with adult LCP offenders are rare; the expected degree of impairment and which mechanisms are unclear. This research adopted a neurocognitive framework that proposes three cognitive mechanisms of impulse control: decision-making, perceptual control, and motor impulse control. Participants were 77 adult males, predominantly LCP prisoners completed five assessment tasks during pre-treatment assessment. Overall, proportions of impairment were unexpectedly low within and across cognitive impulse control domains. The highest proportions of impairment were observed on tasks requiring cognitive flexibility and sustained attention, and only cognitive flexibility uniquely predicted estimated pre-treatment violence risk. Results suggest the need to disaggregate cognitive from personality and behavioural variants of impulsivity and to further investigate how impaired cognitive flexibility affects progress during and following treatment.

Key words:

• clinical impairment
• cognitive impulse control
• high-risk prisoners
• life-course persistent offenders
• treatment

Acknowledgements

We would like to acknowledge the support of the New Zealand Department of Corrections staff and offenders in completing this research, and Gina Grimshaw (Victoria University of Wellington).

Disclosure Statement

No potential conflict of interest was reported by the authors.

Notes

1. For 15 the index offence was a violent sexual assault on an adult victim.

2. The mean stop signal delay at which approximately 50% of trials are inhibited. A threshold of 50% inhibition is the point at which performance data are reliable enough to estimate SSRT from.

3. That is, tasks were administered in one of five pre-determined orders (not fully randomised) but participants were sequentially allocated to one of the orders to randomise order effects.