Figure 3.

Performance in the set-shift behavioural assessment for Experiment 1 and 2 (mean ± SD). Average number of trials to criterion in the intradimensional (ID) & extradimensional (ED) attention-shifts. Ischemic damage to the MD thalamic nucleus significantly impaired animals’ ability to shift attention to a new dimension compared to sham surgery (*p = 0.012). There were no other differences among conditions (a). There were no differences among animals in generalized simple (SD) or compound discriminations (CD), perseveration (Reversal test 1, (REV1) and Reversal test 2 (REV2)) or learned irrelevance (b). As in Experiment 1, MD ischemic lesions significantly impaired attention shifting to a new dimension (ED) compared to sham surgery (*p = 0.003) (c). Chronic exposure to HFSS significantly impaired animals’ generalized ability to shift attention (ED; *p = 0.024) (d) and resulted in significant perseveration (e; REV 2; p = 0.005). There was no effect of diet or lesion on discrimination ability or learned irrelevance (f).