Spatial Memory In Amnesia: Evidence from Korsakoff Patients

Abstract

Two experiments are reported which investigated a hypothesised disproportionate deficit in amnesic spatial memory. Korsakoff amnesic memory for the locations of objects or words placed on a grid was compared to control memory which had been attenuated by longer delays before testing. The effects of incidental versus intentional encoding of the locations were compared. No significant evidence of a disproportionate spatial memory deficit in Korsakoff amnesia was found, intentional instructions did not improve Korsakoff amnesic spatial memory scores, and there was no significant evidence of a trade-off of item memory and location memory specific to the Korsakoff amnesic group. Rather, intentional instructions significantly reduced item memory in both Korsakoff amnesics and normal controls, while having no effect on spatial memory. When location was scored by lenient criteria, there was no significant difference between groups for this measure, nor for recall and recognition memory for these items. Thus Korsakoff amnesic memory was very similar to that of control memory attenuated by longer delays before testing. The Korsakoff amnesic subjects' memory therefore differed quantitatively rather than qualitatively from that of control subjects' memory.

The performance of amnesic subjects on tests of delayed matching-to-sample and delayed matching-to-position

“…This, when taken into consideration with the equivalent control performance on the spatial and nonspatial tasks, means that the present study found no evidence that amnesic subjects were disproportionately impaired on the test of spatial memory. This conclusion is in agreement with a number of other recent studies [9,18]. There is, however, some counter evidence to suggest that amnesics can show disproportionate deficits on the recall of stimulus location when compared with stimuli recognition [20,31].…”

“…This discovery has led a number of researchers to compare spatial with nonspatial memory in amnesics. While some studies have found no evidence of a difference [9,18], others have reported a disproportionate deficit on the spatial components of a memory task [20,31].…”

Judgment and memory performance for emotional stimuli in patients with alcoholic Korsakoff syndrome

“…However, Kensinger, Piguet, Krendl, and Corkin (2005) showed in a recent study that the memory performance for emotional contents is independent of the encoding instruction (incidental vs. intentional) in older healthy participants. KS participants' memory performance also seems not to benefit from intentional compared to incidental encoding as implied by previous studies with neutral material (Chalfonte, Verfaellie, Johnson, & Reiss, 1996;Kovner, Dopkins, & Goldmeier, 1988;MacAndrew & Jones, 1993) as well as with emotional stimuli (Douglas & Wilkinson, 1993). Thus, we assume that the memory impairments of the KS patients are not merely provoked by our experimental design.…”

The Structure and Organization of Memory

“…Further, some spatial tasks might be failed because they approximate tests of source mcmory---e.g, tests in which spatial location provides important context for what is to be remembered. Finally, a recent study of human amnesia found only proportionate impairments of spatial memory relative to recall and recognition memory, using variations of the same tasks just described (MacAndrew & Jones 1993). An additional complication is that many of the amnesic patients in these studies had frontal lobe pathology, which can especially affect recall performance and can cause source amnesia (Janowsky et al 1989;Janowsky et al 1989b;Jetter et al 1986).…”