Biology subjects

Motyka, P.

Publications and source records attributed to Motyka, P..

4 recordsLinked to original sources

bioRxiv2024

Investigating the role of sensorimotor spatial dependencies in shaping conscious access to virtual 3D objects

According to sensorimotor accounts of perceptual experience, the subjective veridicality of an object (the sense of its presence) builds up gradually as one learns how changes in sensory inputs depend on bodily movements. To investigate how sensorimotor interactions shape visual experience, we designed a virtual-reality-based study that allowed us to manipulate the complexity of spatial dependencies governing interactions with unfamiliar 3D objects. Participants had to learn to manually control fully visible objects that could move in congruent, opposite, novel (orthogonal), or random directions in response to their movements. The sensorimotor control tasks occurred alternately with a continuous flash suppression (CFS) task evaluating the access of stationary objects to visual awareness, operationalised as the time taken for a 3D object to break the interocular suppression. We hypothesised that objects whose motion was experienced as depending on actions in a lawful, and thus encodable, manner (i.e., according to a congruent, opposite, or novel - but not random - dependency) would overcome suppression faster than objects moving randomly in response to actions (for which there is no world-related statistical structure to learn). However, while performance in the sensorimotor tasks consistently decreased along with the difficulty of the conditions (i.e., congruent > opposite > novel > random), the pre-registered analysis yielded no significant differences in breakthrough times of objects manipulated under different coupling rules. An exploratory analysis assessing whether the acquisition of sensorimotor mastery was associated with reduced breakthrough times also revealed no significant effects. Thus, our results suggest that ones knowledge of how an object responds to action does not play a salient role in determining conscious access to visual stimuli. This extends previous evidence for a general ineffectiveness of sensorimotor spatial manipulations in interocular suppression paradigms. Notably, in all conditions, object movement remained tightly coupled (i.e., contingent) to the participants actions - and given such stimuli have already been shown to break suppression faster than uncoupled/pre-recorded visual inputs - it is possible that sensorimotor contingency was a sufficiently salient factor to override any influences related to how identifiable specific spatial dependencies were. HighlightsLearning sensorimotor control over objects was examined in novel VR tasks. We varied the complexity of spatial dependencies between manual and visual rotations. Controllable objects were expected to enter visual awareness faster in b-CFS. No differences in breakthrough times for differently complex spatial coupling rules. Sensorimotor contingency outweighs spatial congruence in affecting visual awareness.

neuroscience↗

bioRxiv2024

No cardiac phase bias for threat perception under naturalistic conditions in immersive virtual reality

Previous studies have found that threatening stimuli are more readily perceived and more intensely experienced when presented during cardiac systole compared to diastole. Also, threatening stimuli are judged as physically closer than neutral ones. In a pre-registered study, we tested these effects and their interaction using a naturalistic (interactive, 3D) experimental design in immersive virtual reality: We briefly displayed threatening and non-threatening animals (four each) at varying distances (1.5-5.5 meters) to a group of young, healthy participants (n = 41), while recording their ECGs (electrocardiograms). Participants then pointed to the location where they had seen the animal (ca. 29k trials in total). Our pre-registered analyses indicated that perceived distances to both threatening and non-threatening animals did not differ significantly between cardiac phases - with Bayesian analysis supporting the null hypothesis. There was also no evidence for an association between subjective fear and perceived proximity to threatening animals. These results contrast with previous findings that used verbal or declarative distance measures in less naturalistic experimental conditions. Furthermore, our findings suggest that the cardiac phase-related variation in threat processing may not generalize across different paradigms and may be less relevant in naturalistic scenarios than under more abstract experimental conditions. Impact statementTo our knowledge, this is the first study to assess the influence of interoceptive cardiac signals on visual perception using naturalistic stimuli in immersive virtual reality. We based the design of our experiment on previous reports about threat processing biases and the role of the cardiac cycle but did not observe the expected effects. This poses the question of their generalizability from abstract settings to more naturalistic setups, featuring greater behavioral engagement and a richer sensory environment.

physiology↗

bioRxiv2019

Heart-Brain Interactions Shape Somatosensory Perception and Evoked Potentials

Human perception either refers to the external world, exteroception, or internal body parts such as the heart, interoception. How these two types of perception interact is poorly understood. Using electroencephalography, we identify two heartbeat-related modulations of conscious somatosensory perception: (i) When stimulus timing coincided with systole of the cardiac cycle, participants were less likely to detect and localize somatosensory stimuli, and late components (P300) of the somatosensory-evoked potential (SEP) were attenuated. (ii) The amplitude of the heartbeat-evoked potential (HEP) negatively correlated with detection bias (criterion) and localization accuracy. Furthermore, higher HEP amplitudes were followed by decreases in both early and late SEP amplitudes. Both heartbeat-related effects were independent of the alpha oscillations influence on somatosensory processing. We conclude that internal signals are integrated into our conscious perception of the world, and connect our results to predictive processing (heartbeat-coupled stimulus timing) and attentional shifts between exteroception and interoception (HEP amplitude).

neuroscience↗

bioRxiv2019

Interactions between cardiac activity and conscious somatosensory perception

Fluctuations in the hearts activity can modulate the access of external stimuli to consciousness. The link between perceptual awareness and cardiac signals has been investigated mainly in the visual and auditory domain. We here investigated whether the phase of the cardiac cycle and the pre-stimulus heart rate influence conscious somatosensory perception. We also tested how conscious detection of somatosensory stimuli affects the heart rate. Electrocardiograms (ECG) of 33 healthy volunteers were recorded while applying near-threshold electrical pulses at a fixed intensity to the left index finger. Conscious detection was not uniformly distributed across the cardiac cycle but significantly higher in diastole than in systole. We found no evidence that the heart rate before a stimulus influenced its detection but hits (correctly detected somatosensory stimuli) led to a more pronounced cardiac deceleration than misses. Our findings demonstrate interactions between cardiac activity and conscious somatosensory perception, which highlights the importance of internal bodily states for sensory processing beyond the auditory and visual domain. Impact StatementIt is highly debated to what extent cardiac activity modulates the access of external stimuli to consciousness. The evidence is inconsistent across sensory modalities and previous research focused at specific intervals within the cardiac cycle. Here, we examined the perception of near-threshold electrical pulses across the entire cardiac cycle. Our results show that conscious somatosensory perception is enhanced during the late phase of the cardiac cycle (at diastole) and associated with a more pronounced cardiac deceleration (as compared to non-detected stimuli). This strengthens the evidence that the physiological state of the body influences how we perceive the world.

neuroscience↗