title: The effect of stimulus features on working memory of categorical and coordinate spatial relations in patients with unilateral brain damage.
abstract: Spatial relations are typically divided into categorical and coordinate spatial relations. Categorical relations are abstract and show a left hemisphere (LH) advantage, whereas coordinate relations are metric and related to a right hemisphere (RH) advantage. In the current study a working memory task was used to asses categorical and coordinate performance with two different stimulus sets. In this task, participants had to compare two sequentially presented stimuli, consisting of a dot and a cross. The cross size used in the stimuli was either large or small; a direct manipulation of the amount of information provided to determine a category, or to assess a distance. Patients with damage in the LH or the RH and highly comparable controls were tested. In control participants, categorical processing is faster with the use of a large cross, i.e., more visual information about category boundaries. In contrast, coordinate performance was more accurate with a small cross, i.e., presenting less unnecessary visual information. LH patients showed a specific defect in processing categorical stimuli with a small cross and coordinate stimuli with a large cross. The RH patients were impaired in all conditions except for the categorical small cross condition. We conclude that a larger amount of information present in stimuli increases categorical processing performance and decreases coordinate processing performance, while opposite effects are found for less stimulus information.
authors.affiliation: Helmholtz Institute, Experimental Psychology, Utrecht University, the Netherlands. c.j.m.vanderham@uu.nl
authors.forename: Ineke J M
authors.initials: IJ
authors.lastname: van der Ham
authors.forename: Richard J A
authors.initials: RJ
authors.lastname: van Wezel
authors.forename: Anna
authors.initials: A
authors.lastname: Oleksiak
authors.forename: Martine J E
authors.initials: MJ
authors.lastname: van Zandvoort
authors.forename: Catharina J M
authors.initials: CJ
authors.lastname: Frijns
authors.forename: L Jaap
authors.initials: LJ
authors.lastname: Kappelle
authors.forename: Albert
authors.initials: A
authors.lastname: Postma
mesh_terms: D000328:Adult; D000368:Aged; D001925:Brain Damage, Chronic / Q000523:psychology*; D002545:Brain Ischemia / Q000150:complications / Q000523:psychology; D003627:Data Interpretation, Statistical; D004522:Educational Status; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D020521:Stroke / Q000209:etiology / Q000523:psychology