Neurophysiology of Active Perception

===== Do rhythmic patterns in perceptual sensitivity reflect a clocking mechanism linking motor and perceptual processes? ===== We perceive the world as continuous, yet our perception fluctuates in a rhythmic manner. For one reason, this is because we make saccadic eye movements, during which our perception is drastically altered. However, these rhythmic fluctuations appear to be a more general phenomenon, as has recently been demonstrated in a psychophysical study conducted by Alice Tomassini, a new member of my lab. In this paper ([[http://www.jneurosci.org/content/35/18/7019.short|read it here]]), Alice showed the involvement of the motor system in these rhythmic fluctuations . This study found rhythmic oscillations in visual contrast sensitivity time-locked to the onset of voluntary hand movements. Importantly, the oscillations in visual perception emerge already during motor planning, approximately 500 ms before movement. These findings suggest an automatic coupling between early motor planning and early visual processing. One possible explanation for these observations is that a common brain rhythm regulates in concert both motor and sensory processes. Such a rhythm could provide a common clocking mechanism and link the intention with the ensuing movement and its perceptual consequences across multiple domains. However, the current picture is broadly incomplete, mainly because the specificity of the hypothesized sensory-motor oscillatory coupling has not been investigated. Is it a general functional coupling driven by a cross-modal and effector-aspecific common clocking mechanism? In this project, you will conduct a behavioural experiment that will elucidate one aspect of the hypothesised sensory-motor oscillatory coupling. Depending on the interest and skill of the students, we may also record eye-movements or the electromyogram, both of which will inform us more directly about the hypothesized common clocking mechanism. Depending on the number of participating students, we will conduct one or more experiments that all focus on one aspect of the hypothesised clocking mechanism. All participating students will be participants in the other students' experiments. Students must have an interest in the relation between neurophysiology and behaviour. Moreover, they should be able to program in Matlab. If they do not have this skill, they should follow the Matlab course of the BA3 Psychology program. All experiments will be supervised by Alice Tomassini and Eric Maris.