We used a frequency tagging paradigm to study brain networks mediating non-spatial, object-based attention. The stimuli were sequences of compound images of faces and houses flickering at different tagging frequencies. Our fMRI-guided analysis of the MEG signals revealed that the responses in FFA and PPA were enhanced by attention to faces and houses respectively. Outside of visual cortex, responses to faces vs. houses were also modulated by attention in the inferior frontal junction (IFJ) and, to a much smaller extent, in parietal cortex (PC). The IFJ showed coherent interactions at the gamma frequencies with FFA and PPA during attention to faces vs. houses, respectively. Independent DTI tractography confirmed that IFJ was connected with both FFA and PPA. Our results suggest that IFJ is a key source of signals for the top-down modulation of object attention in visual cortex.
Neural mechanisms of object-based attention in MEG
Baldauf, Daniel;
2013-01-01
Abstract
We used a frequency tagging paradigm to study brain networks mediating non-spatial, object-based attention. The stimuli were sequences of compound images of faces and houses flickering at different tagging frequencies. Our fMRI-guided analysis of the MEG signals revealed that the responses in FFA and PPA were enhanced by attention to faces and houses respectively. Outside of visual cortex, responses to faces vs. houses were also modulated by attention in the inferior frontal junction (IFJ) and, to a much smaller extent, in parietal cortex (PC). The IFJ showed coherent interactions at the gamma frequencies with FFA and PPA during attention to faces vs. houses, respectively. Independent DTI tractography confirmed that IFJ was connected with both FFA and PPA. Our results suggest that IFJ is a key source of signals for the top-down modulation of object attention in visual cortex.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione
