Project for a student CNS Master - Science - Medical Biology - Bewegingswetenschappen:
"Corollary discharge dysfunction, a cognitive marker for autism spectrum disorders?"
Research group: Auditory System, Sensorimotor control, and Multisensory Integration.
Dept. Biophysics.
Supervisors:
prof. dr. John van Opstal, Donders Neurophysics Unit - Dept. Biophysics, HG00.830 Tel: 024-361 4251
prof. dr. Jan Buitelaar, Dept. Cognitive Neuroscience (UMCN) - Afdeling Psychiatrie
Brief description of the Project:
Research Question: Corollary discharge dysfunction, a cognitive marker for autism spectrum disorders?
Background:
Unambiguous neurobiological markers of Autism Spectrum Disorders (ASD) are lacking. Here we test the Ô"corollary discharge" (CD) hypothesis that ASD involves a neurobiological impairment that affects the ability to create an adequate image of your own behavior, as well as the capacity to derive meaningful interpretations from the environment which serves as a base for upcoming actions. Deficits in these basic mechanisms would lead to higher-order social and cognitive symptoms. In this project we will explore two important manifestations of these mechanisms that require the use of a CD signal, and are hypothesized to be affected in ASD.
- Programming a saccadic gaze shift to a briefly flashed target that suddenly jumps to a new location requires accurate and immediate access to self-generated movements of eyes and head. A CD signal representing the programmed saccade travels along a well-identified neuronal network incorporating the midbrain superior colliculus, the thalamus, cortical frontal eye field and parietal cortex. To rigorously test the CD hypothesis of ASD, we measure saccadic eye- and eye-head movements in ASD patients engaged in double-step orienting tasks that require fast (millisecond range) and accurate spatial remapping.
- In natural environments stimuli can have unpredictable behavior in space and time. To cope with this uncertain situation, the normal brain constantly searches for regularities in the environment to enable fast and accurate responses through multisensory integration. By manipulating the predictability of audiovisual stimuli, we assess whether ASD patients can extract such implicit statistical information.
By recording head-unrestrained gaze saccades we develop simple diagnostic procedures to quantify the extent to which ASD patients (i) incorporate self-movements, (ii) extract relevant target information from noisy audiovisual environments, and (iii) are sensitive to audiovisual pop-out.
Aim: The study will lead to a publication in a peer-reviewed international scientific journal (e.g., the Journal of Neuroscience).
Proposed start: any time
Background knowledge:
Master CNSc: The obligatory courses of the Perception and Action program. The elective course on Auditory
Perception.
Science (Natuurwetenschappen): Psychofysica 1, Neurofysica 1, (Neurobiofysica).
Medical Biology, Bewegingswetenschappen: Neurobiofysica; Hersenen en Gedrag: Sensorimotoriek
If you are interested in this project, please contact prof dr. John van Opstal (address, see above, and web page).
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