Further evidence for a multidimensional personality disposition to schizophrenia in terms of cognitive inhibition.

Abstract

A study is reported using the 'negative priming' paradigm to examine individual differences in cognitive inhibition in relation to distinct features of schizotypy. Seventy psychology students completed four measures of schizotypy, selected to index specific schizotypal traits: the Schizotypy Scale (STA), the Magical Ideation (MI) Scale, the Revised Social Anhedonia (SoA) Scale and the Physical Anhedonia (PhA) Scale. The priming paradigm was based on that of Beech, McManus, Baylis & Agar (1991), including conventional repeat and semantic priming conditions as well as repeat and semantic negative priming conditions, but differed in terms of task and stimuli. Cluster analysis of STA scores revealed a four-cluster solution reflecting 'very low', 'moderately low', 'moderately high' and 'very high' STA scores. Cluster analysis of MI, SoA, and PhA Scale scores also revealed four clusters. The first cluster comprised those with low scores on all scales. The remaining three clusters were distinguished by those with high MI, high SoA, and high PhA Scale scores, respectively. Those with high STA, MI, and SoA scale scores showed a significantly reduced, or reversed, repeat and semantic negative priming effect compared to those with moderately low STA scores and those low on all scales, respectively. An unexpected finding was that participants with high and moderately high STA scores as well as those with high MI and SoA scores revealed an inhibitory rather than facilitatory conventional repeat priming effect. It is concluded that weakening of inhibitory processes may be associated with a strong presence of schizotypal features related to dimensions of positive schizophrenic symptomatology, whereas schizotypal traits that parallel purely negative schizophrenic symptoms are not linked to reduced inhibition unless there is also a presence of 'positive' schizotypal features. The association of some schizotypal traits with an inhibitory repeat priming effect indicates that stimuli and task differences have a bearing on the attentional processes underlying priming effects for these participants. Thus, Beech et al.'s 'reduced-inhibition' model of schizophrenic symptomatology may require refinement.