Implicit cognition is impaired and dissociable in a head-injured group with executive deficits

BARKER, Lynne, ANDRADE, Jackie, ROMANOWSKI, C. A. J., MORTON, N. and WASTI, A. (2005). Implicit cognition is impaired and dissociable in a head-injured group with executive deficits. Neuropsychologia, 44 (8), 1413-1424.


Download (512kB) | Preview
Link to published version::


Implicit or non-conscious cognition is traditionally assumed to be robust to pathology but Gomez-Beldarrain et al (1999, 2002) recently showed deficits on a single implicit task after head injury. Laboratory research suggests that implicit processes dissociate. This study therefore examined implicit cognition in 20 head-injured patients and age and I.Q.-matched controls using a battery of four implicit cognition tasks: a Serial Reaction Time task (SRT), mere exposure effect task, automatic stereotype activation and hidden co-variation detection. Patients were assessed on an extensive neuropsychological battery, and MRI scanned. Inclusion criteria included impairment on at least one measure of executive function. The patient group was impaired relative to the control group on all the implicit cognition tasks except automatic stereotype activation. Effect size analyses using the control mean and standard deviation for reference showed further dissociations across patients and across implicit tasks. Patients impaired on implicit tasks had more cognitive deficits overall than those unimpaired, and a larger Dysexecutive Self/Other discrepancy (DEX) score suggesting greater behavioural problems. Performance on the SRT task correlated with a composite measure of executive function. Head-injury thus produced heterogeneous impairments in the implicit acquisition of new information. Implicit activation of existing knowledge structures appeared intact. Impairments in implicit cognition and executive function may interact to produce dysfunctional behaviour after head-injury. Future comparisons of implicit and explicit cognition should use several measures of each function, to ensure that they measure the latent variable of interest.

Item Type: Article
Additional Information: The published version of this article is available at:
Uncontrolled Keywords: Executive, Social cognition, Non-conscious processes, Fractionated, Head injury
Research Institute, Centre or Group - Does NOT include content added after October 2018: Psychology Research Group
Identification Number:
Page Range: 1413-1424
Depositing User: Ann Betterton
Date Deposited: 20 Jul 2007
Last Modified: 18 Mar 2021 05:02

Actions (login required)

View Item View Item


Downloads per month over past year

View more statistics