Acquisition and baseline performance of working memory tasks by adolescent rhesus monkeys

Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA.
Brain research (Impact Factor: 2.84). 03/2011; 1378:91-104. DOI: 10.1016/j.brainres.2010.12.081
Source: PubMed


Adolescence is a transitional stage of development characterized by protracted refinements in the neural circuits required for adult level proficiency of working memory. Because impaired working memory is a hallmark feature of several psychiatric disorders that have their onset during adolescence, model systems that can be used to assess the maturation of working memory function, and of disease-related risk factors that disrupt its development, are of particular importance. However, few studies have investigated the maturation of working memory in nonhuman primates. Thus in the present study, we adapted two working memory tests that are among the most widely used in human and adult nonhuman primates, for adolescent rhesus monkeys. Using a touch-screen apparatus, monkeys were trained on a spatial delayed-response task to assess spatial working memory and a delayed match-to-sample task to assess object working memory. The results indicate that adolescent rhesus monkeys readily and efficiently acquire the ability to perform touch-screen based, complex tests of working memory. These data establish that distinct components of adult prefrontal cortex-dependent cognitive functions can be effectively modeled and evaluated in adolescent monkeys. As such, this approach should be useful for assessing the influence of environmental risk factors on the protracted maturation of working memory in adolescent macaques.

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Available from: Christopher D Verrico
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    • "Measurements of behavioral performance in nonspatial delayed-match-to-sample tasks have been interpreted as showing that monkeys remember the sample using working memory, that is, they use selective memorization (Miller and Desimone 1994; Amit et al. 2003; Schneider et al. 2009; Verrico et al. 2011). However, this interpretation has been made even when the delayed-match-to-sample task does not include intervening distractors (Schneider et al. 2009; Verrico et al. 2011), which are critical for distinguishing selective memorization from the neighborhood strategy. Even tasks that included intervening distractors often did not repeat those images as the test image (Miller et al. 1993; Woloszyn and Sheinberg 2009). "
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