EN
The present project aims at investigating factors underlying 'learned irrelevance', one of the cognitive mechanisms that is responsible for extradimensional shifting deficits. In the attentional set-shifting task (N = 70) subjects were required to learn a series of visual discriminations on the basis of feedback presented after each trial. Complex stimuli consisting of three perceptual dimensions: colour, shape and number of contributing elements were used. In the final stage of the task subjects had to switch attention to the perceptual dimension, which had been previously either fully irrelevant (50% of co-occurrence with the relevant dimension during the previous task stages) or partially reinforced (75% of co-occurrence with the previously relevant dimension). The quality of that dimension was also manipulated (shape or number of elements). According to the expectations, partial reinforcement of the irrelevant dimension may facilitate the shifting process, reducing the 'earned irrelevance' effect, as measured by the accuracy rate.