Amnesia Research Today is a free monthly online journal that collates and summarizes the latest research about Amnesia, including details on memory loss, causes, treatment, brain injury,.

Disruption of sequential priming in organic and pharmacological amnesia: a role for the medial temporal lobes in implicit contextual learning.

Shanks DR, Channon S, Wilkinson L, Curran HV

Department of Psychology, University College London, London, UK. d.shanks@ucl.ac.uk

We examined learning and expression of contextual implicit learning of a sequence of targets in a speeded target-detection task in amnesic and control participants. Amnesia was of organic origin in one participant group and induced psychopharmacologically (diazepam 7.5 or 15 mg) in another. Although the amnesic groups were able to learn the target sequence normally, their expression of sequence knowledge (priming) was attenuated when contextual support was limited. This was evaluated by studying response latencies for targets primed by between 0 and 5 preceding context locations. Whereas control participants showed priming when the current target location was primed by only two previous locations, priming was eliminated with two (but not four) previous locations by a low dose of diazepam and was eliminated even with four elements of context under a high dose of diazepam and in amnesia of organic origin. The results suggest that a function of the hippocampal memory system is to support contextual learning and performance, even when that learning is nondeclarative.

Published 18 July 2006 in Neuropsychopharmacology, 31(8): 1768-76.
Full-text of this article is available online (may require subscription).

© 2004-2008 Amnesia Research Today. All Rights Reserved.