IMPAIRED TEMPORAL CONTEXT MEMORY ON ANTEROGRADE BUT NOT RETROGRADE TESTS IN THE ABSENCE OF FRONTAL PATHOLOGY

This study examined the memory performance of patient RK who developed substantial memory impairments due to a hypothalamic glioma but in th e absence of any evidence of frontal disturbance. RK was evaluated on both tests of anterograde and retrograde memory for temporal context. In the first experiment he exhibited marked deficits on a list discrim ination task even when recognition performance was well within control range. Experiment 2 confirmed this disproportionate impairment of tem poral order memory and showed that RK's list discrimination deficit wa s as severe as that found in alcoholic Wernicke-Korsakoff Syndrome pat ients. Experiment 3 showed that RK's temporal discrimination deficit w as not a general deficit in discrimination because he performed normal ly on a spatial discrimination test of comparable difficulty to the te mporal task. Experiment 4 examined RK's memory for deceased famous peo ple and his ability to indicate the half decade in which they died. RK 's performance was indistinguishable from controls whereas WKS patient s were extremely impaired. This study adds to the view that frontal da mage is not a necessary condition for impairment on anterograde measur es of temporal context memory. However, further evidence from this stu dy indicates that temporal judgments about pre-existing memories may d epend on intact frontal lobe functioning.