TL neuro

February 29, 2012

Δ9-Tetrahydrocannabinol impairs visuo-spatial associative learning and spatial working memory

Filed under: Cannabis, CANTAB, Cognition, MDMA, SOSS, vsPAL — mtaffe @ 6:59 am

This paper has been accepted for publication:

Taffe, M.A. Δ9-Tetrahydrocannabinol impairs visuo-spatial associative learning and spatial working memory in rhesus macaques, J Psychopharmacol, October 2012 26: 1299-1306, first published on April 22, 2012 doi:10.1177/0269881112443743 [PubMed] [DOI]

In this paper we show that acute treatment with Δ9-THC interferes with the performance of two memory tasks in a manner that depends on both trial difficulty within the task and the dose administered. These results contrast with much prior literature using recognition memory or related tasks in which the effect of THC did not appear to be task specific, i.e., degrading performance in a difficulty-dependent manner. Our results are consistent with a prior observations using spatial delayed response tasks, further emphasizing a role for intact endocannabinoid function in spatial and/or working memory and learning.

Figure 3. The mean (N=4; ±SEM) percentage of trials correctly performed in the vsPAL task on the first attempt, and after a maximum of 6 attempts, are presented for baseline, vehicle and THC treatment conditions. The open symbols indicate significantly improved trial completion after repetition when compared with the initial attempt for a given treatment condition and trial type. Within a given trial-difficulty level, a significant difference from the vehicle and baseline conditions is indicated by #, from the vehicle condition (only) by &, and a difference from the 0.1 mg/kg condition by *.

August 4, 2011

CANTAB Self-Ordered Spatial Search Task: Strategy paper

Filed under: CANTAB, SOSS — mtaffe @ 11:40 am

This paper is now published [updated 9/2/2011]

Michael A. Taffe and William J. Taffe. Rhesus monkeys employ a procedural strategy to reduce working memory load in a self-ordered spatial search task. 2011, Br Res, 1413: 43-50. [DOI]

The object in this task is to select each box once and only once for a successful trial completion. A two second delay between each response and a manual distraction means that memory is required for successful completion. Subjects adopt a distance-minimizing response-path strategy that is correlated with successful trial completion. This correlation is observed between individuals and across months of training within individuals.

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