Recollection and familiarity in negative schizophrenia

Using the "remember-know" procedure to assess recognition memory, previous studies yielded evidence of impaired recollection but intact familiarity in schizophrenia patients. However, so far, the recognition memory performance of schizophrenia patients has not yet been analysed using the dual-process signal detection model (DPSD) by Yonelinas [Yonelinas, A. P. (2001). Components of episodic memory: The contribution of recollection and familiarity. Philosophical Transactions of Royal Society of London. Series B: Biological Sciences, 356(1413), 1363-1374], which accurately accounts for response and memory bias. Also, clinical symptoms have not yet been taken into account. Based on findings from neuropsychological and neurobiological research we hypothesized that high negative symptoms might be associated with a profile of impaired recollection and spared familiarity. The recognition memory performance of 22 schizophrenia patients scoring higher or lower on the negative symptoms subscale of the Positive and Negative Syndrome Scale (PANSS) was assessed by means of a word list discrimination task. Following the rationale of the dual-process signal detection model, estimates of recollection and familiarity were derived. The recollection estimate, derived by the DPSD model, was lower in patients with more severe negative symptomatology compared with both the patients with lower negative symptoms scores and healthy individuals. Familiarity was not affected if IQ was partialled out. Furthermore, the results yielded increased false alarm rates in patients with negative schizophrenia. The findings confirm an association of negative symptoms and recollection impairment in schizophrenia.