Cognitive Neuroscience Talks

Stimulus selectivity: when task matters

Numerous neuroimaging studies aim to demonstrate that a given brain area processes a restricted category of stimuli: the FFA for faces, VWFA for words and so forth. However, across studies one can observe variations in the level of activity according to the task used. I report here an fMRI experiment using letter perception that illustrate that task matters. Results demonstrate that the brain response to letters is not selective but specific, i.e. that the difference observed for letters depends on the task. In addition, looking at the BOLD amplitude vs. dynamic, our data showed a dissociation category vs. task suggesting that categories are encoded across different brain areas whereas the task modulate the access to these area.