Biology subjects

Tivadar, R. I.

Publications and source records attributed to Tivadar, R. I..

3 recordsLinked to original sources

bioRxiv2020

Uncovering the mechanisms of real-world attentional control over the course of primary education

Schooling may shape childrens abilities to control their attention, but it is unclear if this impact extends from control over visual objects to encompass multisensory objects, which are more typical of everyday environments. We compared children across three primary school grades ([country] 1st, 3rd, and 5th grade) on their performance on a game-like audio-visual attentional control task, while recording their EEG. Behavioral markers of visual attentional control were present from 3rd grade (after 2 years of schooling), whereas multisensory attentional control was not detected in any group. However, multivariate whole-brain EEG analyses ( electrical neuroimaging) revealed stable patterns of brain activity that indexed both types of attentional control - visual control in all groups, and multisensory attentional control from 3rd grade onwards. Multivariate EEG approaches can uncover otherwise undetectable mechanisms of attentional control over visual and multisensory objects and characterize how they differ at different educational stages. Lay AbstractWe measured how visual and audiovisual distractors differ in capturing the attention of 1st- to 5th-graders while recording the childrens brain activity. Brain activity results showed that all children were sensitive to visual distraction, and from 3rd grade onwards, children were also sensitive to audiovisual distraction. These results deepen our understanding of how school children control their attention in everyday environments, which are made up of information that stimulates multiple senses at a time.

neuroscience↗

bioRxiv2020

The development of attentional control mechanisms in multisensory environments

Outside the laboratory, people need to pay attention to relevant objects that are typically multisensory, but it remains poorly understood how the underlying neurocognitive mechanisms develop. We investigated when adult-like mechanisms controlling ones attentional selection of visual and multisensory objects emerge across childhood. Five-, 7-, and 9-year-olds were compared with adults in their performance on a computer game-like multisensory spatial cueing task, while 129-channel EEG was simultaneously recorded. Markers of attentional control were behavioural spatial cueing effects and the N2pc ERP component (analysed traditionally and using a multivariate electrical neuroimaging framework). In behaviour, adult-like visual attentional control was present from age 7 onwards, whereas multisensory control was absent in all children groups. In EEG, multivariate analyses of the activity over the N2pc time-window revealed stable brain activity patterns in children. Adult-like visual-attentional control EEG patterns were present age 7 onwards, while multisensory control activity patterns were found in 9-year-olds (albeit behavioural measures showed no effects). By combining rigorous yet naturalistic paradigms with multivariate signal analyses, we demonstrated that visual attentional control seems to reach an adult-like state at ~7 years, before adult-like multisensory control, emerging at ~9 years. These results enrich our understanding of how attention in naturalistic settings develops. HighlightsO_LIBy age 7, children showed adult-like task-set contingent attentional capture in behaviour C_LIO_LIChildrens behavioural data did not show evidence for attentional enhancement for multisensory objects, but 9-year-olds EEG topographic patterns elicited by multisensory vs. purely visual distractors differed reliably C_LIO_LITraditional visual attentional event-related potential (ERP) analyses, such as the N2pc, did not detect attentional enhancement for multisensory objects in adults, and visual or multisensory attention in children C_LIO_LIMultivariate analyses of ERPs, such as electrical neuroimaging, are more sensitive to the change of attentional control processes over development C_LI

neuroscience↗

bioRxiv2019

Auditory enhancement of illusory contour perception

Illusory contours (ICs) are borders that are perceived in the absence of contrast gradients. Until recently, IC processes were considered exclusively visual in nature and presumed to be unaffected by information from other senses. Electrophysiological data in humans indicates that sounds can enhance IC processes. Despite cross-modal enhancement being observed at the neurophysiological level, to date there is no evidence of direct amplification of behavioural performance in IC processing by sounds. We addressed this knowledge gap. Healthy adults (N=15) discriminated instances when inducers were arranged to form an IC from instances when no IC was formed (NC). Inducers were low-constrast and masked, and there was continuous background acoustic noise throughout a block of trials. On half of the trials, i.e. independently of IC vs. NC, a 1000Hz tone was presented synchronously with the inducer stimuli. Sound presence improved the accuracy of indicating when an IC was presented, but had no impact on performance with NC stimuli (significant IC presence/absence x Sound presence/absence interaction). There was no evidence that this was due to general alerting or to a speed-accuracy trade-off (no main effect of sound presence on accuracy rates and no comparable significant interaction on reaction times). Moreover, sound presence increased sensitivity and reduced bias on the IC vs. NC discrimination task. These results demonstrate that multisensory processes augment mid-level visual functions, exemplified by IC processes. Aside from the impact on neurobiological and computational models of vision our findings may prove clinically beneficial for low-vision or sight-restored patients.

neuroscience↗