title: Failures of cognitive control or attention? The case of stop-signal deficits in schizophrenia.
abstract: We used Bayesian cognitive modelling to identify the underlying causes of apparent inhibitory deficits in the stop-signal paradigm. The analysis was applied to stop-signal data reported by Badcock et al. (Psychological Medicine 32: 87-297, 2002) and Hughes et al. (Biological Psychology 89: 220-231, 2012), where schizophrenia patients and control participants made rapid choice responses, but on some trials were signalled to stop their ongoing response. Previous research has assumed an inhibitory deficit in schizophrenia, because estimates of the mean time taken to react to the stop signal are longer in patients than controls. We showed that these longer estimates are partly due to failing to react to the stop signal ("trigger failures") and partly due to a slower initiation of inhibition, implicating a failure of attention rather than a deficit in the inhibitory process itself. Correlations between the probability of trigger failures and event-related potentials reported by Hughes et al. are interpreted as supporting the attentional account of inhibitory deficits. Our results, and those of Matzke et al. (2016), who report that controls also display a substantial although lower trigger-failure rate, indicate that attentional factors need to be taken into account when interpreting results from the stop-signal paradigm.
authors.affiliation: Department of Psychology, University of Amsterdam, Postbus 15906, 1001 NK, Amsterdam, The Netherlands. d.matzke@uva.nl.
authors.forename: Dora
authors.initials: D
authors.lastname: Matzke
authors.affiliation: Brain and Psychological Sciences Centre, Swinburne University of Technology, Hawthorn, Australia.
authors.forename: Matthew
authors.initials: M
authors.lastname: Hughes
authors.affiliation: Centre for Clinical Research in Neuropsychiatry, School of Psychiatry and Clinical Neurosciences, The University of Western Australia, Crawley, Australia.
authors.forename: Johanna C
authors.initials: JC
authors.lastname: Badcock
authors.affiliation: School of Psychology and Centre for Brain and Mental Health Research, University of Newcastle, Callaghan, Australia.
authors.forename: Patricia
authors.initials: P
authors.lastname: Michie
authors.affiliation: School of Medicine, University of Tasmania, Hobart, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Heathcote
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D001499:Bayes Theorem; D002755:Choice Behavior / Q000502:physiology; D003071:Cognition / Q000502:physiology*; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012559:Schizophrenia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012565:Schizophrenic Psychology
keywords: Attention deficits; Inhibition deficits; Schizophrenia; Stop-signal paradigm; Trigger failure