Ranking Cognitive Flexibility in a Group Setting of Rhesus Monkeys with a Set-Shifting Procedure

Abstract

Attentional set-shifting ability is an executive function underling cognitive flexibility in humans and animals. In humans, this function is typically observed during a single experimental session where dimensions of playing cards are used to measure flexibility in the face of changing rules for reinforcement (i.e., the Wisconsin Card Sorting Test (WCST)). In laboratory animals, particularly non-human primates, variants of the WCST involve extensive training and testing on a series of dimensional discriminations, usually in social isolation. In the present study, a novel experimental approach was used to assess attentional set-shifting simultaneously in 12 rhesus monkeys. Specifically, monkeys living in individual cages but in the same room were trained at the same time each day in a set-shifting task in the same housing environment. As opposed to the previous studies, each daily session began with a simple single-dimension discrimination regardless of the animal’s performance on the previous session. A total of eight increasingly difficult, discriminations (sets) were possible in each daily 45 min session. Correct responses were reinforced under a second-order schedule of flavored food pellet delivery, and criteria for completing a set was 12 correct trials out of a running total of 15 trials. Monkeys progressed through the sets at their own pace and abilities. The results demonstrate that all 12 monkeys acquired the simple discrimination (the first set), but individual differences in the ability to progress through all eight sets were apparent. A performance index (PI) that encompassed progression through the sets, errors and session duration was calculated and used to rank each monkey’s performance in relation to each other. Overall, this version of a set-shifting task results in an efficient assessment of reliable differences in cognitive flexibility in a group of monkeys.

Low cognitive flexibility as a risk for heavy alcohol drinking in non-human primates

“…Each housing cage was equipped with an operant panel as previously described (Shnitko et al, 2017;Vivian et al, 2001). Each panel included a centrally located dowel and 2 drinking spouts, and below one of the spouts there was a food receptacle connected to a 1 g pellet dispenser (Med Associates Inc., USA) and below the receptacle there was a recessed well that could detect the insertion of a finger via the breaking of an infrared beam.…”

“…There are several ways to measure cognitive flexibility in humans and animals. Predominantly, variations of the Wisconsin Card Sorting Test (WCST) that uses intradimensional-extradimensional shifts in serial visual discrimination sets are applied across species (Brown & Tait, 2016;Floresco et al, 2008;Roberts et al, 1988;Shnitko et al, 2017). Specifically, an "attentional set" of stimuli is presented where the relevant dimension of each stimulus (for example, the shape or the color) is learned by a trial and error approach.…”

“…In a variation of the procedures described above, the touch screen can be integrated into a side-wall of the NHP housing cage. Further, simultaneous assessment of individual set-shifting ability within a group of monkeys is possible (Shnitko et al, 2017). Thus the acquisition and progression through multiple sets of visual discriminations can be directly compared within and across subjects in this group setting.…”

Behavioral Flexibility in Alcohol‐Drinking Monkeys: The Morning After

“…Each subject in the study had access to water, EtOH solution, food, and the set‐shift task through operant panels integrated into one of the walls of each housing cage (Grant et al, ; Shnitko et al, ; Vivian et al, ). In addition, controls received calorically matched 10% maltose–dextrin via a separate hanging bottle on the front of the cage.…”

Different Electrophysiological Responses to Informative Value of Feedback Between Children and Adults

“…In the development of infancy and childhood, the ability to learn from inappropriate behavior and flexibly switch to the proper performance is important for their daily school life ( Dajani and Uddin, 2015 ; Hauser et al, 2015 ; Wolff et al, 2016 ; Shnitko et al, 2017 ). The most typical paradigm to study cognitive flexibility is rule-learning task.…”