Garcia Alanis, J. C. | Search bioRxiv

bioRxiv2023

Neurocognitive Dynamics of Preparatory and Adaptive Cognitive Control: Insights from Mass-Univariate and Multivariate Pattern Analysis of EEG data

Cognitive control encompasses a set of basic perceptual and reasoning processes that help us align thoughts and actions with goals. While a growing body of research indicates that these processes can be independently engaged and tuned to fit different tasks (e.g., behavioural preparation vs behavioural adaptation), the dynamic interplay of these processes and their functional timing within the information stream, remains elusive. In this study, we used a combination of mass-univariate and multivariate pattern analysis to examine electroencephalography data from 52 participants, recorded during performance of the Dot Pattern Expectancy Task (DPX), a task designed to assess both preparatory and adaptive cognitive control. Contrary to the notion of isolated neural signatures for either cognitive control mode, our data indicates that cognitive control engages a sequence of distinct yet partially overlapping brain activation patterns. Preparatory cue-stimuli evoked early transient occipital-parietal amplitude responses that were followed by enhanced sustained central-parietal and fronto-central amplitude responses. Similarly, adaptive probe-stimuli evoked enhanced early transient occipital-parietal amplitude responses, but these were followed by enhanced transient, fronto-central and central parietal amplitude responses. Moreover, we found significant relationships between the magnitude of the central-parietal and fronto-central amplitude response pattern and behavioural performance in the DPX. This research not only extends prior work but also offers valuable insights into the functional timing and organisation of the neurocognitive processes underpinning both preparatory and adaptive cognitive control.

neuroscience↗

bioRxiv2022

Let's face it: The lateralization of the face perception network as measured with fMRI is not clearly right dominant

The neural face perception network is distributed across both hemispheres. However, the dominant role in humans is virtually unanimously attributed to the right hemisphere. Interestingly, there are, to our knowledge, no imaging studies that systematically describe the distribution of hemispheric lateralization in the core system of face perception across subjects in large cohorts so far. To address this, we determined the hemispheric lateralization of all core system regions (i.e., occipital face area (OFA), fusiform face area (FFA), posterior superior temporal sulcus (pSTS)) in 108 healthy subjects using functional magnetic resonance imaging (fMRI). We were particularly interested in the variability of hemispheric lateralization across subjects and explored how many subjects can be classified as right-dominant based on the fMRI activation pattern. We further assessed lateralization differences between different regions of the core system and analyzed the influence of handedness and sex on the lateralization with a generalized mixed effects regression model. As expected, brain activity was on average stronger in right-hemispheric brain regions than in their left-hemispheric homologues. This asymmetry was, however, only weakly pronounced in comparison to other lateralized brain functions (such as language and spatial attention) and strongly varied between individuals. Only half of the subjects in the present study could be classified as right-hemispheric dominant. Additionally, we did not detect significant lateralization differences between core system regions. Our data did also not support a general leftward shift of hemispheric lateralization in left-handers. Only the interaction of handedness and sex in the FFA revealed that specifically left-handed men were significantly more left-lateralized compared to right-handed males. In essence, our fMRI data did not support a clear right-hemispheric dominance of the face perception network. Our findings thus ultimately question the dogma that the face perception network - as measured with fMRI - can be characterized as "typically right lateralized".

neuroscience↗