Stimulus degradation impairs performance in a rodent continuous performance test

Abstract

Sustained attention is a core cognitive domain that is often disrupted in neuropsychiatric disorders. Continuous performance tests (CPTs) are the most common clinical assay of sustained attention. In CPTs, participants produce a behavioral response to target stimuli and refrain from responding to non-target stimuli. Performance in CPTs is measured as the ability to discriminate between targets and non-targets. Rodent versions of CPTs (rCPT) have been developed and validated with both anatomical and pharmacological studies, providing a translational platform for understanding the neurobiology of sustained attention. In human studies, using degraded stimuli (decreased contrast) in CPTs impairs performance and patients with schizophrenia experience a larger decrease in performance compared to healthy controls. In this study, we tested multiple levels of stimulus degradation in a touchscreen version of the CPT in mice. We found that stimulus degradation significantly decreased performance in both males and females. The changes in performance consisted of a decrease in stimulus discrimination, measured as d prime, and increases in hit reaction time and reaction time variability. These findings are in line with the effects of stimulus degradation in human studies. Overall, female mice demonstrated a more liberal response strategy than males, but response strategy was not affected by stimulus degradation. These data extend the utility of the mouse CPT by demonstrating that stimulus degradation produces equivalent behavioral responses in mice and humans. Therefore, the degraded stimuli rCPT has high translational value as a preclinical assay of sustained attention.

Patterns of neural activity in prelimbic cortex neurons correlate with attentional behavior in the rodent continuous performance test

“…rCPT training protocol was based on a previously described protocol [35]. Briefly, mice were trained in the touchscreen chambers, which were connected to a computer running ABET II software (Campden Instruments, Loughborough, UK) to track behavioral responses during rCPT sessions.…”

“…Behavioral data was analyzed using Excel to obtain performance scoring parameters. Performance scoring parameters were similar to those described in [13] and [35]. Briefly, to assess attention performance during Stage 3 training, we calculated discrimination index d' with the following formula: d' = z(hit rate) -z (FA rate) Whereas: hit rate (HR) = hits / hits + misses FA rate (FAR) = false alarms / false alarms + correct rejections .…”

Electrophysiological correlates of attention in the locus coeruleus - anterior cingulate cortex circuit during the rodent continuous performance test

“…The rCPT training protocol was based on a previously described protocol [39]. Briefly, mice were trained in Bussey-Saksida mouse touchscreen chambers (Lafayette Instruments).…”

“…Training stage details are provided in supplement. Performance scoring parameters were similar to those described by [20] and [39]. Briefly, to assess attention performance during Stage 3, we calculated the discrimination index d', which is a measure of sensitivity bias (perceptual discriminability between S+ and S−) and c, which is a measure of response bias (willingness to make responses).…”