Flexible Memory Processing by Rats: Use of Prospective and Retrospective Information in the Radial Maze

Investigated the content of the memory used by rats in mediating retention intervals interpolated during performance in a 12-arm radial maze, using 10 Sprague-Dawley rats in Exps I and II and 21 Long-Evans rats in Exps III and IV. The delay occurred following either the 2nd, 4th, 6th, 8th, or 10th choice. A 15-min delay had the greatest disruptive effect when interpolated in the middle of the choice sequence and less of an effect when it occurred either earlier or later. This pattern was obtained when either a free- or forced-choice procedure was used prior to the delay and regardless of whether postdelay testing consisted of completion of the maze or 2-alternative forced-choice tests. Assuming that the disruptive effect of a delay is a function of memory load, this implies that Ss used information about previously visited arms (retrospective memory) following an earlier interpolated delay but information about anticipated choices (prospective memory) following a delay interpolated late in the choice sequence. There appeared to be a recency effect only in the early and middle delay conditions. Data provide converging evidence for the dual-code hypothesis. No evidence for prospective memory was obtained following a 60-min delay. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)

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Main Author: Cook, Robert
Other Authors: Brown, Michael, Riley, Donald
Language: English
Published: 1985
Online Access: http://ezproxy.villanova.edu/login?url=http://digital.library.villanova.edu/Item/vudl:175043