¹University of Cambridge, Department of Psychology, Cambridge, United Kingdom, ²Boehringer Ingelheim Pharma GmbH & Co KG, CNS Diseases Research, Biberach an der Riss, Germany

Background: Flexible attention in real-world settings requires the ability to divide and shift attention across sensory modalities. However, most rodent attention paradigms assess unimodal sensory processing and are poorly suited to studying cross-modal attentional control. Previous attempts to develop such rodent divided-attention tasks have often required prolonged training periods, limiting their practicality and uptake. There is therefore a need for efficient, cognitively relevant behavioural assays that capture cross-modal attention while remaining feasible for experimental neuroscience.

Aims & Objectives: This study aimed to develop a novel, efficient rodent cross-modal divided attention task and to validate its relevance to attentional control by testing its sensitivity to pharmacological disruption.

Method: This experiment redesigned a previously abandoned version of a cross-modal divided attention task that required several months of training, rebuilding the paradigm from the ground up using contemporary principles of rodent behavioural design. Key features included locating all task elements on a single wall of the operant chamber, delivering reward at the point of decision, requiring self-initiated trials, and training multimodal discriminations prior to unimodal conditions. Male Sprague-Dawley rats were trained to discriminate both solid and pulsing visual and auditory signals presented randomly within the same session. Average training time to criterion was 21 sessions. Task validity was assessed by pharmacological disruption using the NMDA receptor antagonist MK-801, a compound known to impair attentional and cognitive control processes, with particular relevance to the cognitive deficits observed in disorders such as schizophrenia.

Results: Subjects acquired the novel cross-modal divided attention task rapidly and reliably, with substantially reduced training time compared to earlier task versions. Administration of MK-801 dose-dependently impaired task performance, while basic task engagement and sensory discrimination remained comparatively preserved. These deficits indicate a disruption of attentional control rather than motor or motivational impairment.

Discussion & Conclusions: This study introduces a novel, efficient rodent cross-modal divided attention task that is both practical and cognitively meaningful. Sensitivity to MK-801 demonstrates that the task is amenable to disruption of attentional control mechanisms, supporting its validity as a behavioural assay of flexible attention. This paradigm provides a cutting-edge tool for investigating attentional processes and their pharmacological modulation, with clear applications in preclinical cognitive neuroscience and drug discovery.