A SINGLE‑SESSION AUTOMATED AUDIO ATTENTIONAL SET‑SHIFTING TASK SENSITIVE TO PHARMACOLOGICAL MANIPULATION IN RATS<EM> </EM>

Attentional set‑shifting (ASS) tasks are widely regarded as a gold‑standard measure of cognitive flexibility due to their well-established construct validity, pharmacological sensitivity, and across‑species translatability. However, automated rodent ASS paradigms remain challenging to implement because their bespoke apparatus, multi‑session protocols, and the challenge in creating perceptually salient stimuli that rodents perceive as truly compound. We developed a fully automated, single‑session auditory ASS task that overcomes these limitations and enables rapid, high‑throughput assessment of cognitive flexibility in rats and validated its pharmacological sensitivity using the noncompetitive NMDA receptor antagonist MK‑801 to induce impairments. Thirty‑two adult male Lister Hooded rats underwent audio discrimination training before completing the multi‑stage ASS task following administration of MK‑801 and vehicle. The task comprised three stages: simple discrimination (SD), compound discrimination (CD), and an extradimensional shift (ED). In SD, rats discriminated tones based on a single perceptual dimension (e.g., amplitude). In CD and ED, tones contained two dimensions (amplitude and modulation). After developing a bias toward one dimension during SD and CD, rats were required at ED to shift attention to the previously irrelevant dimension. Shifting between auditory dimensions produced a robust shift cost, independent of shift direction. This cost was further exacerbated by MK-801 administration. These results demonstrate that our single-session, automated operant task is sensitive to pharmacological disruption of cognitive flexibility. The task provides a robust, efficient tool for assessing attentional set-shifting deficits and offers a scalable approach for preclinical research on cognitive inflexibility.