Differential mesolimbic and prefrontal alterations during reward anticipation and consummation in positive and negative schizotypy.

Schizotypy is associated with anhedonia. However, previous findings on the neural substrates of anhedonia in schizotypy are mixed. In the present study, we measured the neural substrates associated with reward anticipation and consummation in positive and negative schizotypy using functional MRI. The Monetary Incentive Delay task was administered to 33 individuals with schizotypy (18 positive schizotypy (PS),15 negative schizotypy (NS)) and 22 healthy controls. Comparison between schizotypy individuals and controls were performed using two-sample T tests for contrast images involving gain versus non-gain anticipation condition and gain versus non-gain consummation condition. Multiple comparisons were corrected using Monte Carlo Simulation correction of p<.05. The results showed no significant difference in brain activity between controls and schizotypy individuals as a whole during gain anticipation or consummation. However, during the consummatory phase, NS individuals rather than PS individuals showed diminished left amygdala and left putamen activity compared with controls. We observed significantly weaker activation at the left ventral striatum during gain anticipation in NS individuals compared with controls. PS individuals, however, exhibited enhanced right ventral lateral prefrontal activity. These findings suggest that different dimensions of schizotypy may be underlied by different neural dysfunctions in reward anticipation and consummation.

Latent factor structure of the Das-Naglieri Cognitive Assessment System: a confirmatory factor analysis in a Chinese setting.

This study aims to measure the psychometric properties of the Das-Naglieri Cognitive Assessment System (D-N CAS) and to determine its clinical utility in a Chinese context. Confirmatory factor analysis (CFA) was conducted to examine the construct validity of the Chinese version of the D-N CAS among a group of 567, normally developed children. Test-retest reliability was examined in a random subsample of 30 children at a five-week interval. The clinical discrimination of the D-N CAS was also examined by comparing children with and without ADHD (18 children in each group) and by comparing children with and without Chinese reading disabilities (18 children in each group). The current Chinese sample demonstrated a four-factor solution for cognitive performance among children with normal development: Planning, Attention, Simultaneous processing and Successive processing (χ2(48)=91.90, p=.000; χ2/df=1.92, RMSEA=.050, GFI=.966, CFI=.954). Moreover, all subtests of the battery demonstrated acceptable test-retest reliability (r=.72-.90, p<.01) at a five-week interval among the subjects of the small subsample. Children with ADHD performed significantly worse than normal children on the Attention factor (p<.001) and the Planning factor (p<.05) of the D-N CAS, and children with Chinese reading disabilities performed significantly worse than normal children on the Simultaneous processing factor (p<.01), the Successive processing factor (p<.001) and the Planning factor (p<.05) of the D-N CAS. These findings suggested that the current four-factor structure of the D-N CAS was similar to the original factor structure of the test. The latent factor of the D-N CAS was fairly stable across the cultures. Moreover, the D-N CAS can distinguish between children with ADHD or Chinese reading disabilities and normally developed children.