Delineating a parietal-anterior cingulate-claustrum circuit underlying cognitive control and attention Treatments are urgently needed for cognitive dysfunction in psychiatric patients. Given the link between such dysfunction and outcome in patients, large numbers of clinical trials were conducted with companies attempting to be ‘first-to-market’. In the rush however, preclinical studies used had limited validity to the cognitive domains reportedly targeted. Thus, circuit-engagement of the cognitive domain tested was rarely if-at-all verified and all clinical trials to-date have failed. New paradigms have emerged with reported relevance to domains affected in psychiatry, but little opportunity to validate circuits underlying these behaviors, let-alone drugs that modulate such circuits and behavior, have arisen. This application will utilize a circuit-targeted approach to confirm the utility of the 5-choice continuous performance test (5C-CPT) to measure cognitive control and attention across multiple psychiatric disorders. Specific Aim 1 will optimize the touchscreen 5C-CPT for parametric manipulation. The 5C-CPT exists for mice, rats, and humans, with EEG & fMRI versions. The task has always been standard however, primarily in 5-hole operant chambers, but a touchscreen version with parametric manipulations within the task would improve translatability to human testing and enable task performance-based consistency. Backward masking of stimuli have been used in cognitive control tasks previously, but only recently used in human 5C-CPT studies. Here, we will demonstrate that such masked trials enable parametric assessment of 5C-CPT performance in mice. Specific Aim 2 will determine the pharmacological sensitivity of the touchscreen 5C-CPT. After developing the task, it is important to confirm that it is sensitive to manipulations, including those available for use in humans for pharmacological predictive validation. We demonstrated that modafinil improves healthy human participant performance of the standard 5C-CPT, while scopolamine impairs mouse performance. Here, we will confirm that modafinil and scopolamine similarly affect this masked touchscreen 5C-CPT, while predicting that a dopamine D4 receptor agonist would improve cognitive control. We will confirm that modafinil rescues scopolamine-induced deficits, avoiding receptor tautological complications. Specific Aim 3 will confirm the role of the anterior cingulate cortex (ACC)claustrum and claustrumparietal cortex (PC) circuit underlying this masked touchscreen 5C-CPT performance. Consistent with human CPTs, we confirmed the necessity of the PC for mouse 5-choice (5C-)CPT performance. We hypothesize that a ACC to claustrum projection is important during more cognitively demanding trials (from parametric manipulations), while a claustrum to PC projection occurs is important for selecting whether to respond or not during trials. Using fiber photometry and optogenetic techniques, we will confirm...