Biology subjects

Hyona, J.

Publications and source records attributed to Hyona, J..

3 recordsLinked to original sources

bioRxiv2024

Modelling human social vision with cinematic stimuli

Sociability is central for humans. Visual information ranging from low-level physical features (e.g. luminance) to semantic information (e.g. face recognition) and high-level social inference (e.g. emotional valence of social interactions) is constantly sampled for navigating the social world. Here we utilize large-scale eye tracking during natural vision for mapping how different levels of visual information guide the perception of social scenes. In three experiments, participants (N = 166) watched full-length films and short movie clips with varying social content (total duration: 193 minutes) during eye tracking. To model the association between the perceptual features and spatiotemporal eye movement parameters (gaze position, gaze synchronization, pupil size and blinking), we extracted 39 stimulus features from the movies including low-level audiovisual features (e.g. luminance, motion), presence and location of mid-level semantic categories (e.g. faces, objects) and high-level social information (e.g. body movements, pleasantness). Pupil size was modulated by luminance, scene cuts and emotional arousal while gaze position was most accurately predicted by a combination of the presence of human faces, local motion and entropy. Faces and eyes were prioritized over other semantic categories and blinking rate decreased during periods of attentional engagement. Altogether the results show that human social vision is primarily guided by low-level physical features and mid-level semantic categories, while high-level social features such as emotional arousal primarily modulate pupillary responses.

neuroscience↗

bioRxiv2024

Endogenous opioid system modulates proximal and distal threat signals in the human brain

BACKGROUNDFear promotes rapid detection of threats and appropriate fight-or-flight responses. The endogenous opioid system modulates responses to pain and psychological stressors. Opioid agonists also have also anxiolytic effects. Fear and anxiety constitute major psychological stressors for humans, yet the contribution of the opioid system to acute human fear remains poorly characterized. METHODSWe induced intense unconditioned fear in the subjects by gradually exposing them to a living constrictor snake (threat trials) versus an indoor plant (safety trials). Brain haemodynamic responses were recorded from 33 subjects during functional magnetic resonance imaging (fMRI). In addition, 15 subjects underwent brain positron emission tomography (PET) imaging using [11C]carfentanil, a high affinity agonist radioligand for -opioid receptors (MORs). PET studies under threat or safety exposure were performed on separate days. Pupillary arousal responses to snake and plant exposure were recorded in 36 subjects. Subjective fear ratings were measured throughout the experiments. RESULTSSelf-reports and pupillometric responses confirmed significant experience of fear and autonomic activation during the threat trials. fMRI data revealed that proximity with the snake robustly engaged brainstem defense circuits as well as thalamus, dorsal attention network, and motor and premotor cortices. These effects were diminished during repeated exposures. PET data revealed that [11C]carfentanil binding to MORs was significantly higher during the fear versus safety condition, and the acute haemodynamic responses to threat were dependent on baseline MOR binding in the cingulate gyrus and thalamus. Finally, baseline MOR tone predicted dampening of the haemodynamic threat responses during the experiment. CONCLUSIONSPreparatory response during acute fear episodes involves a strong motor component in addition to the brainstem responses. These haemodynamic changes are coupled with a deactivation of the opioidergic circuit, highlighting the role of MORs in modulating the human fear response.

neuroscience↗

bioRxiv2023

Beta- and gamma-band oscillatory connectivity support naturalistic reading of continuous text

Large-scale integration of information across cortical structures, building on neural connectivity, has been proposed to be a key element in supporting human cognitive processing. In electrophysiological neuroimaging studies of reading, quantification of neural interactions has been limited to the level of isolated words or sentences due to artefacts induced by eye movements. Here, we combined magnetoencephalography recording with advanced artefact rejection tools to investigate both cortico-cortical coherence and directed neural interactions during naturalistic reading of full-page texts. Our results show that reading vs. visual scanning of text was associated with wide-spread increases of cortico-cortical coherence in the beta- and gamma-bands. We further show that the reading task was linked with increased directed neural interactions compared to the scanning task across a sparse set of connections within a wide range of frequencies. Together, the results demonstrate that neural connectivity flexibly builds on different frequency bands to support continuous natural reading.

neuroscience↗