Theta synchronization over occipito‐temporal cortices during visual perception of body parts

Abstract

Categorical clustering in the visual system is thought to have evolved as a function of intrinsic (intra-areal) and extrinsic (interareal) connectivity and experience. In the visual system, the extrastriate body area (EBA), an occipito-temporal region, responds to full body and body part images under the organizational principle of their functional/semantic meaning. Although frequency-specific modulations of neural activity associated with perceptive and cognitive functions are increasingly attracting the interest of neurophysiologists and cognitive neuroscientists, perceiving single body parts with different functional meaning and full body images induces time-frequency modulations over occipito-temporal electrodes are yet to be described. Here, we studied this issue by measuring EEG in participants who passively observed fingers, hands, arms and faceless full body images with four control plant stimuli, each bearing hierarchical analogy with the body stimuli. We confirmed that occipito-temporal electrodes (compatible with the location of EBA) show a larger event-related potential (ERP, N190) for body-related images. Furthermore, we identified a body part-specific (i.e. selective for hands and arms) theta event-related synchronization increase under the same electrodes. This frequency modulation associated with the perception of body effectors over occipito-temporal cortices is in line with recent findings of categorical organization of neural responses to human effectors in the visual system.

Orchestration of brain oscillations: principles and functions

“…Moreau et al . () make the intriguing observation that images of humans induce a greater synchronization of theta activity in occipito‐temporal areas. The study by Kaiser et al .…”

Prolonged and unprolonged complex febrile seizures differently affect frontal theta brain activity

“…Although we used an auditory learning task, spatial and temporal coincidence of auditory and visual stimuli can lead to unintentional processing in the irrelevant modality (Driver and Spence, 2000), explaining an occipito-temporal cluster. In adults, slow frequencies at occipito-temporal sites have mainly been associated with visual perception (Moreau et al, 2018) and lexical semantic association (Bastiaansen et al, 2008). Still, as our hypothesis focussed on learning processes in early-childhood, a fronto-central ROI was a preferable candidate in our study, Slow frequency bands are among the first to develop (Whitford et al, 2007) and earlychildhood brain signal is characterized by predominance of slow activity .…”

Interpersonal Motor Interactions Shape Multisensory Representations of the Peripersonal Space

“…Electroencephalographic (EEG) studies highlighted the presence of specific fronto-central markers (in particular theta/alpha synchronisation) occurring when performing errors [184] or observing errors performed by one's own avatar in a first-person perspective [185][186][187][188]. Furthermore, recent studies using transcranial alternating current stimulation provided evidence for a causal role of midfrontal theta activity during conflict monitoring [189], and a causal role of midfrontal and occipito-temporal theta activity (observed when participants are presented with stimuli depicting hands in EEG studies, [190,191]) in a task where conflict is elicited by hand stimuli [192].…”