Biology subjects

Vaina, L. M.

Publications and source records attributed to Vaina, L. M..

3 recordsLinked to original sources

bioRxiv2018

Maturation Trajectories of Cortical Resting-State Networks Depend on the Mediating Frequency Band

The functional significance of resting state networks and their abnormal manifestations in psychiatric disorders are firmly established, as is the importance of the cortical rhythms in mediating these networks. Resting state networks are known to undergo substantial reorganization from childhood to adulthood, but whether distinct cortical rhythms, which are generated by separable neural mechanisms and are often manifested abnormally in psychiatric conditions, mediate maturation differentially, remains unknown. Using magnetoencephalography (MEG) to map frequency band specific maturation of resting state networks from age 7 to 29 in 162 participants (31 independent), we found significant changes with age in networks mediated by the beta (13-30Hz) and gamma (31-80Hz) bands. More specifically, gamma band mediated networks followed an expected asymptotic trajectory, but beta band mediated networks followed a linear trajectory. Network integration increased with age in gamma band mediated networks, while local segregation increased with age in beta band mediated networks. Spatially, the hubs that changed in importance with age in the beta band mediated networks had relatively little overlap with those that showed the greatest changes in the gamma band mediated networks. These findings are relevant for our understanding of the neural mechanisms of cortical maturation, in both typical and atypical development.

neuroscience↗

bioRxiv2018

The emotional valence and features of subliminal priming images impact conscious perception of facial expressions

We investigated, in young healthy subjects, how the affective content of subliminally presented priming images and their specific visual attributes impacted conscious perception of facial expressions. The priming images were broadly categorised as aggressive, pleasant, or neutral and further subcategorised by the presence of a face and by the centricity (egocentric or allocentric vantage-point) of the image content. Subjects responded to the emotion portrayed in a pixelated target-face by indicating via key-press if the expression was angry or neutral. Priming images containing a face compared to those not containing a face significantly impaired performance on neutral or angry target-face evaluation. Recognition of angry target-face expressions was selectively impaired by pleasant prime images which contained a face. For egocentric primes, recognition of neutral target-face expressions was significantly better than of angry expressions. Our results suggest that, first, the affective primacy hypothesis which predicts that affective information can be accessed automatically, preceding conscious cognition, holds true in subliminal priming only when the priming image contains a face. Second, egocentric primes interfere with the perception of angry target-face expressions suggesting that this vantage-point, directly relevant to the viewer, perhaps engages processes involved in action preparation which may weaken the priority of affect processing.

neuroscience↗

bioRxiv2018

Cross-Modal Cue Effects in Motion Transparency Processing

The everyday environment brings about many competing inputs from different modalities to our sensory systems. The ability to filter these multisensory inputs in order to identify and efficiently utilize useful spatial cues is necessary to detect and process the relevant information. In the present study, we investigate how feature-based attention affects the detection of motion across sensory modalities. We were interested to determine how subjects use intramodal, crossmodal auditory, and combined audiovisual motion cues to attend to specific visual motion signals. The results show that in most cases, both visual and auditory cues enhance feature-based orienting to a visual motion pattern that is presented among distractor patterns. Furthermore, in many cases, detection of transparent motion patterns was significantly more accurate after combined visual-auditory than unimodal attention cues. Whereas previous studies have shown crossmodal effects of spatial attention, our results demonstrate a spread of crossmodal feature-based attention cues, which have been matched for the detection threshold of the visual target. These effects were evident in comparisons between cued and uncued conditions, as well as in analyses comparing the effects of valid vs. invalid cues.

neuroscience↗