Asymptomatic biological parents of a patient with schizophrenia show impairments in recognition memory

Background:
Recognition memory dysfunction has been frequently reported in schizophrenic populations, and has been linked with the development of delusions and thought disorder. A range of neuropsychological abnormalities have also been documented in the biological asymptomatic relatives of patients with schizophrenia; however, recognition memory has not been one of them.
Aim:
This study was carried out in order to investigate: (i) verbal and facial recognition memory in terms of accuracy and false alarm rates; and (ii) contributions from the episodic and semantic memory systems to recognition memory, in the biological asymptomatic parents of a reported schizophrenic patient and a set of male and female psychotic controls.
Results:
Gender differences failed to emerge between the psychotic controls on any of the recognition measures (discrimination accuracy, response bias, hit and false alarm rates, ‘remember’ and ‘know’ recognition memory decisions). However, there was evidence of recognition dysfunction in the female relative, and to a lesser extent, in the male. Both parent's recognition memory performance profiles were marked by a pathologically elevated false alarm rate, and an increased dependence ‘remember’ judgements, i.e. input from the episodic memory system, to drive recognition memory decisions.
Conclusions:
These findings are discussed in the context of models of episodic and semantic memory impairment in schizophrenia.