Hits and False Alarms in Recognition Memory Show Differential Impairment in Positive and Negative Schizotypy

摘要

The present study examined the extent to which positive and negative schizotypy are associated with impairment in recognition memory in 3 large samples of nonclinically ascertained adults (total n = 826). Schizophrenia is associated with a wide array of cognitive deficits, but the study of cognitive impairment in schizophrenia is confounded by generalized performance deficits related to symptoms and consequences of the disorder, and by failure to separately examine positive and negative symptom dimensions. Schizotypy provides a promising framework for examining these deficits relatively unconfounded by symptoms and sequelae of the disorder. The present study obtained recognition memory deficits in positive and negative schizotypy across verbal and figural stimuli in three different samples. Importantly, although discrimination accuracy is impaired across higher scores on both schizotypy dimensions, the mechanism of impairment differs across positive and negative schizotypy. Negative, but not positive, schizotypy was associated with impaired hit rates, whereas the false alarm rates remained unaffected. In contrast, positive, but not negative, schizotypy was associated with increased false alarm rates despite stable hit rates. The results are discussed from the perspective of a signal-detection theoretic model that accounts for negative schizotypy results through reduced signal mechanism, and accounts for positive schizotypy results through increased noise mechanism. These findings further support the utility of multidimensional schizotypy for assessing and understanding episodic memory impairment in the schizophrenia spectrum.