Periodic Reporting for period 4 - BBRhythms (Brain and body rhythms: on the relationship between movement and percept)
Berichtszeitraum: 2021-01-01 bis 2021-06-30
In subproject 1 we investigated percept related neural and behavioral output during free walking. We could show that walking is associated with a decrease in oscillatory alpha activity over occipital cortex independent of the visual input. Walking further leads to an upregulation of early visual neuronal activity in humans, corroborating animal findings. Extending the animal work, our results present evidence that the neuronal modulation due to walking is linked to specific perceptual changes.
Dissemination
Cao, L., Chen, X., & Händel, B., (2020) Frontiers in Human Neuroscience
Cao, L., Händel. B. (2019) PLoS biology
Outreach press: Pour La Science: https://www.pourlascience.fr/sd/neurosciences/la-marche-intensifie-la-vision-peripherique-18566.php
Gehirn und Geist: https://www.spektrum.de/magazin/gehen-veraendert-die-wahrnehmung/1695558
In subproject 2 we specifically investigated eye related movements. We could show that the duration of cognitive or sensory processing is the driving factor for the timing of blinks and that a blink marks the end of a processing period. Using visual and auditory bistable stimuli, we found evidence that a reinterpretation of bistable sensory input indeed preferably happens during the time of no blinks. Accordingly, subjects with a higher blink rate have a lower rate of perceptual switches. Overall, our work indicates that blinks are tightly linked to sensory perceptual processes however, contrary to our initial hypothesis, blinks seem not to influence the perceptual interpretation but rather perceptual stability.
Dissemination
Murali, S., Händel, B. (2021) Journal of Vision
M. Brych, B. Händel., (2020). International Journal of Psychophysiology
Murali, S., Brych, M., Händel, B. (2021) Frontiers in Psychology
In a third line of research, we investigated the relationship between different types of movements. We find that eye related movements (pupil size, blinks and saccades) are modulated by walking speed and phase. Further, corroborating earlier results that the blink rate is increased during a conversation, we could ascribe this increase mainly to an interaction between facial muscle movements and blinking. Our work on eye related movements, walking and speaking gives evidence that motor systems are tightly linked.
Brych, M., Murali, S., Händel, B. PLOS ONE (accepted)
Brych, M., Händel, B., et al, (2020). Psychophysiology
Overall, our current findings clearly support our hypothesis that walking modulates visual cortical activity as well as eye related movements, thereby changing the perceptual outcome during movement as compared to standing still. They further confirm a role of blinks in domain general perceptual processes and show that the interaction between body movements is a key feature of natural behavior.
Exploitation
Based on our findings that the movement will influence perception, we further looked at the connection of walking to more cognitive factors and find that movement restriction is the driving factor of walking related improvements of creativity measures.
Paper: Murali, S. & Händel, B., Psychological Research, (under review – 2nd revision)
We further investigated less quantitative changes in motor output. In a set of studies, we showed that the perceptual temporal shift during action binding is related to the force of the action.
Cao, L., Steinborn, M., Händel, B. Scientific Report (2021).
Cao, L., Kunde, W., Händel, B., (2020). Journal of Cognitive Neuroscience
Cao, L., Steinborn, M., Kunde, W., & Händel, B. (2020). Experimental Brain Research
Later processing stages ascribed to spatial attention seem unaffected by the movement state while early visual responses are stronger during walking.
Poster: X. Chen, L. Cao, B. Händel (2020): Right visual field advantage during both walking and standing.
Extending the animal work, our methodological approach could generate complementary neurophysiological and behavioral evidence that neuronal modulation due to walking is linked to specific perceptual changes. A follow up study distinguished between early and late perceptual processes, showing that spatial attention is comparable between stationary setups and free walking. Overall, our work clearly shows that strategies of sensory information processing can differ between movement states urging research to more thoroughly embrace movement-state dependencies in order to understand perception during natural behavior.
Another great step towards understanding motor influences relates to the role of blinking in percept. Overall, our work shows that blinks are tightly linked to sensory perceptual processes as well as other body movements such as walking, speaking and eye movements. Based on our studies in the visual and auditory domain we can further propose a testable hypothesis as to the function of spontaneous blinks during perception, namely that a blink helps to stabilize the perceptual interpretation during ongoing movement of the body/eye.
Importantly, our methodology allows to broaden the approach to investigating other cognitive aspects like memory and learning. It can be further used to advance the research field of movement pathologies seen e.g. in Parkinson’s disease or dystonia as well as movement degeneration during healthy aging.