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de Sanctis, T.

Publications and source records attributed to de Sanctis, T..

2 recordsLinked to original sources

Does higher sampling rate (Multiband + SENSE) benefit the detection of task correlated BOLD for cognitive neuroscience applications at 3T?

Multiband (MB) or Simultaneous multi-slice (SMS) acquisition schemes allow the acquisition of MRI signals from more than one spatial coordinate at a time. Commercial availability has brought this technique within the reach of many neuroscientists and psychologists. Most early evaluation of the performance of MB acquisition employed resting state fMRI or the most basic tasks. In this study, we tested whether the advantages of using MB acquisition schemes generalize to group analyses using a cognitive task more representative of typical cognitive neuroscience applications. Twenty-three subjects were scanned on a Philips 3T scanner using five sequences up to eight-fold acceleration with MB-factors 1 to 4, SENSE factors up to 2 and corresponding TRs of 2.45s down to 0.63s, while they viewed (i) movies showing complex actions with hand object interactions and (ii) control movies without hand object interaction. Using random effects group-level, voxel-wise analysis we found that all sequences were able to detect the basic action observation network known to be recruited by our task. The highest t-values were found for sequences with MB4 acceleration. For the MB1 sequence, a 50% bigger voxel volume was needed to reach comparable t-statistics. The group-level t-values for resting state networks (RSNs) were also highest for MB4 sequences. Here the MB1 sequence with larger voxel size did not perform comparable to the MB4 sequence. Altogether, we can thus recommend the use of MB4 (and SENSE 1.5 or 2) on a Philips scanner when aiming to perform group-level analyses using cognitive block design fMRI tasks and voxel sizes in the range of cortical thickness (e.g. 2.7mm isotropic). While results will not be dramatically changed by the use of multiband, our results suggest that MB will bring a moderate but significant benefit.

neuroscience↗

Where and how our brain represents the temporal structure of observed action

Reacting faster to the behavior of others provides evolutionary advantages. Reacting to unpredictable events takes hundreds of milliseconds. Understanding where and how the brain represents what actions are likely to follow one another is therefore important. Everyday actions are predictable sequences of acts, yet neuroscientists focus on how brains responds to unexpected, individual motor acts. Using fMRI we show the brain encodes sequence-specific information in the motor system. Using EEG, we show visual responses were faster and smaller for predictable sequences that recruit the motor system. This study shifts the study of action observation from single acts to motor sequences, informs how we adapt to the actions of others and suggests the motor system may implement perceptual predictive coding.

neuroscience↗