Aims: Auditory recognition memory was investigated in Schizophrenia in terms of remember (i.e. specific recollection) and know (i.e. familiarity without specific recollection) judgements.
Methods: Three groups were investigated: normal controls (N=21) and patients diagnosed with Schizophrenia (N=10) and Major Depressive Disorder, Recurrent (N=10) according to DSM IV criteria. Participants were required to discriminate between previously heard sentences (targets) and novel sentences (distracters).
Results: Results were analysed in terms of hit-rate frequency (number of correct targets), false-alarm rate frequency (number of false alarms), and signal-detection measures of A' (ability to discriminate between targets and distracters), and B''D (response bias i.e. probability of accepting a stimulus as a target when uncertain). Non-parametric tests showed no significant differences for hit-rate frequency, false-alarm rate frequency, A', and B''D. However, significant differences in remember (P<0.001) and know (P<0.05) were found. Patients with Schizophrenia made significantly more know judgements relative to normal controls (P<0.01) and significantly fewer remember judgements relative to normal controls (P<0.001) and patients with Major Depressive Disorder, Recurrent (P<0.01).
Conclusions: Evidence suggests that amongst the reported cohort of patients with Schizophrenia; remember judgements play a significantly reduced contribution to auditory recognition memory compared to normal controls and patients with Major Depressive Disorder, Recurrent.