Research reportPerformance of C57BL/6J and DBA/2J mice on a touchscreen-based attentional set-shifting task

- We compared attentional set-shifting abilities of C57BL/6J and DBA/2J mice in a touchscreen-based task.
- Salience of the relevant dimension was manipulated to assess effects on discrimination performance.
- Performance of C57BL/6J mice was superior to that of DBA/2J mice on the extra-dimensional shift.
- Task performance was dependent on interactions between strain, exemplar group, and salience of the relevant dimension.
- Reversal learning performance of all mice decreased across reversals, likely due to proactive interference.

Attentional set-shifting deficits are a feature of multiple psychiatric disorders. However, the neurogenetic mechanisms underlying these deficits are largely unknown. In the present study we assessed performance of C57BL/6J and DBA/2J mice on a touchscreen-based attentional set-shifting task similar to those used with humans and non-human primates. In experiment 1, mice discriminated simple white lines followed by compound stimuli composed of white lines superimposed on grey shapes. Although performance of the two strains was largely equivalent during early stages of the task, DBA/2J mice committed significantly more errors compared to C57BL/6J mice on the extra-dimensional shift. Additionally, performance of mice as a group declined across the three compound discrimination reversals. In experiment 2 we assessed salience of the shapes and lines dimensions and determined if dimensional salience, a variable previously shown to affect set-shifting abilities in humans and non-human primates, could be systematically manipulated. Findings from experiment 2 suggested that strain differences during the extra-dimensional shift in experiment 1 were most parsimoniously explained by a consistently impaired ability in DBA/2J mice to discriminate a subset of the compound stimuli. Additionally, unlike maze-based tasks, the relative salience of the two dimensions could be manipulated by systematically altering the width of lines exemplars while retaining other potentially-relevant attributes of the compound stimuli. These findings reveal unique and in some cases strain-dependent phenomena related to discriminations of simple and multidimensional visual stimuli which may facilitate future efforts to identify and fully characterize visual discrimination, reversal learning, and attentional set-shifting deficits in mice.