title: Mechanisms underlying selecting objects for action.
abstract: We assessed the factors which affect the selection of objects for action, focusing on the role of action knowledge and its modulation by distracters. Fourteen neuropsychological patients and 10 healthy aged-matched controls selected pairs of objects commonly used together among distracters in two contexts: with real objects and with pictures of the same objects presented sequentially on a computer screen. Across both tasks, semantically related distracters led to slower responses and more errors than unrelated distracters and the object actively used for action was selected prior to the object that would be passively held during the action. We identified a sub-group of patients (N = 6) whose accuracy was 2SDs below the controls performances in the real object task. Interestingly, these impaired patients were more affected by the presence of unrelated distracters during both tasks than intact patients and healthy controls. Note that the impaired patients had lesions to left parietal, right anterior temporal and bilateral pre-motor regions. We conclude that: (1) motor procedures guide object selection for action, (2) semantic knowledge affects action-based selection, (3) impaired action decision making is associated with the inability to ignore distracting information and (4) lesions to either the dorsal or ventral visual stream can lead to deficits in making action decisions. Overall, the data indicate that impairments in everyday tasks can be evaluated using a simulated computer task. The implications for rehabilitation are discussed.
authors.affiliation: School of Psychology, University of Birmingham Birmingham, UK.
authors.forename: Melanie
authors.initials: M
authors.lastname: Wulff
authors.affiliation: School of Psychology, University of Birmingham Birmingham, UK.
authors.forename: Rosanna
authors.initials: R
authors.lastname: Laverick
authors.affiliation: Department of Experimental Psychology, University of Oxford Oxford, UK.
authors.forename: Glyn W
authors.initials: GW
authors.lastname: Humphreys
authors.affiliation: School of Psychology, University of Birmingham Birmingham, UK.
authors.forename: Alan M
authors.initials: AM
authors.lastname: Wing
authors.affiliation: School of Psychology, University of Birmingham Birmingham, UK.
authors.forename: Pia
authors.initials: P
authors.lastname: Rotshtein
keywords: action knowledge; attention; conceptual knowledge; dual route; semantic interference