Brain and body rhythms: on the relationship between movement and percept

Project Information

BBRhythms

Grant agreement ID: 677819

DOI

10.3030/677819

Project closed

EC signature date 5 June 2016

Start date 1 July 2016

End date 30 June 2021

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 1 422 907,00

EU contribution

€ 1 422 907,00

Coordinated by

JULIUS-MAXIMILIANS-UNIVERSITAT WURZBURG
Germany

Periodic Reporting for period 4 - BBRhythms (Brain and body rhythms: on the relationship between movement and percept)

Reporting period: 2021-01-01 to 2021-06-30

Summary of the context and overall objectives of the project

In the awake state, our body is in constant motion and we meet most perceptual challenges while moving. Nevertheless, the vast majority of studies that investigate perception are conducted under strict movement suppression. Findings from animal electrophysiology in the past years however suggest that body movements influence perceptual processes already at a basic level of sensory processing. The main aim of our research was to decode the relationship between body movements and perception in humans. Indeed, our research shows that walking modulates visual cortical activity and changes the perceptual outcome as compared to standing still. At the same time, spatial attention and its neural hallmark behaves similarly during these different movement states. Our work further confirms a role of spontaneous blinks in domain general perceptual processes and shows that the interaction between body movements is a key feature of natural behavior. Indeed, walking, blinking and saccade timing exhibit a clear temporal relationship, aligned with specific periods of sensory processing. Overall, our findings clearly show that motor behavior is deeply intertwined with cognition and that movements and their interactions must be viewed as part of an optimized cognitive system. This can help unraveling cognition during natural behavior, further leading to a better understanding of perceptual/cognitive changes during degraded movements as observed in many neurodegenerative diseases as well as during healthy aging.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

With the use of our newly established functional mobile recording lab, we measured electrophysiology, eye movements, movement pattern and perception in freely moving humans.
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.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

We were able to establish a functional fully mobile recording lab, including EEG/EOG, eye tracking, motion tracking and psychophysical measurements based on visual stimulation. Such approach, allowing unrestrained movement while measuring electrophysiology, movements and perception has, up to now, not been realized in humans and is a major methodological step forward in investigating natural movements in humans.

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.

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