At the same time, one should be aware of the fact that multivaria

At the same time, one should be aware of the fact that multivariate approaches selleck compound library may also be sensitive to confounds that systematically

covary with the conditions of interest. The fact that the GLM identified regions that overlapped with those found by the multivariate approach provides support that the multivariate approach is also driven by neural correlates of shifts in object-based attention. Furthermore, we analysed if the decoding was driven by highly localized activity patterns or by distributed cortical activations by training and testing decoders on individual clusters detected in the GLM. Because decoding on these small individual clusters yielded poor decoding performance compared with the whole-brain or GLM-restricted decoders, it suggests that faces and places are encoded in the brain using distributed patterns cortical activations, and as such detection of these patterns requires a multivariate decoder with input features spread across the brain. Finally, because the MVA-W classifier – trained only on pictures of separately presented faces and places – could not recruit any regions related to attention, we conducted a reverse MVPA to find regions associated with attention.

We trained two classifiers: one on the feedback condition; and the other on the non-feedback condition. Subsequently, these classifiers were tested on the localizer. We not only found activations in the same brain regions PARP signaling responsible for processing faces and places as we found in MVA-W, but also detected

additional brain regions associated with attention and cognitive control. We found activation in superior frontal, middle frontal and superior medial frontal Epothilone B (EPO906, Patupilone) gyri. These are part of the frontal-parietal network that have been known to become active in top-down attentional control paradigms (Li et al., 2010) and during bistable perception in which the observer’s perception can fluctuate between competing stimuli (Knapen et al., 2011). We also found activation in crus I of the left cerebellum. The cerebellum not only plays an important role in motor coordination, but has also been shown to be involved in higher cognitive functions such as selective visual attention (Allen, 1997). Moreover, activations in middle and anterior cingulate were also detected. Previous studies have shown that these regions play a crucial role in attention-demanding tasks by competition monitoring and goal-directed selective attention (Danckert et al., 2000; Davis et al., 2000). Activation in bilateral precuneus was also found, but only in the classifier trained on the non-feedback condition. Activation in this region has been shown in a previous study (Hahn et al., 2006) during engagement of top-down spatial selective attention. This may imply that subjects were engaged in both object-based and space-based visual attention during the non-feedback condition.

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