Large movements (walking) and perception: (Liyu Cao)
Most of our knowledge about human perception stems from laboratory research in which participants were required to sit still, keep fixation, withhold blinks etc. The experimental setting as such is quite different from the situation where perceptual processes naturally occur. Thus, a clear understanding of perception in more natural situations (e.g. when we are walking) is still lacking. In the current project, we are interested in the question how walking influences visual perception and eye-related processes (e.g. saccades and microsaccades). (Wireless) EEG, EOG, eye tracking and motion tracking are the main techniques that will be used in this inquiry.
Small movements (eye related movements) and perception:
- visual perception: (Supriya Murali)
Small eye movements like saccades and blinks have been shown to influence brain activity in early and late visual areas like lateral geniculate nucleus (LGN), V1, V2 and V3. Interestingly, this influence persist even if these movements are executed in darkness and therefore leave the visual input unaltered. At the same time, there are several precept related behaviors that seem linked to eye movements.
This project will investigate the influence of eye movements like blinks, saccades and microsaccades as well as its rate on ongoing oscillatory activity in the visual system.
To this end, neurophysiological data will be recorded from human subjects by means of MEG while eye movements are monitored by an eye tracking device and visual input is controlled.
To study the specific influence of blinks on the ongoing activity within the visual system at single cell resolution electrophysiological data simultaneously recorded in LGN and V1 in macaque monkey using multiple subdural electrodes will be analyzed.
This research project will help to understand how small body movements like eye movements can influence perceptual processes and activity in areas whose neuronal responses are normally not related to movement control but rather to the early processing of sensory input. In addition, the role of blinking and microsaccades in vision can be further clarified.
- sensory integration: (Mareike Brych)
Brain oscillations play a relevant role in perceptual processes and are found in all sensory cortical areas. Interestingly, body movements, such as saccades, can modulate the phase of these ongoing oscillations. Such a phase shift might help to synchronize brain activity within or between sensory areas thereby facilitating the processing of input to different modalities.
We want to investigate the influence of eye movements on ongoing oscillatory activity and perception recording neurophysiological data from human subjects by means of MEG while eye movements are monitored and behavioural tasks are presented.
Additionally, ECoG data recorded from the hippocampus of epileptic patients will be analyzed in order to investigate the influence of blinking on ongoing oscillatory hippocampal activity. The hippocampus plays an important role in cognitive processes such as memory. Interestingly, the hippocampus, without being part of the motor cortex, is highly susceptible to body movements. In humans, saccades have been shown to modulate the phase of hippocampal theta activity in human and non-human primates. The effect of blinks is not known.
This research project will assess the consequences of blinks on perceptual processes and neuronal responses within cortical and subcortical brain areas.