The functional role of gamma oscillations for cortical computations explored through massive parallel recordings

• Applicant: Dr. Danko Nikolic
• Subject Area: Cognitive, Systems and Behavioural Neurobiology
• Term: from 2007 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 53387982

We will use highly parallel recordings of up to 64 channels of neural responses in cat area 17 to address the functional and computational role of gamma oscillations and the associated precise temporal synchronization of neural spiking activity. In particular, we shall study the effects of spontaneous state changes, as reflected by the presence and absence of gamma oscillations, on cortical information processing. Using specially designed silicon probes we shall record simultaneously from large numbers of cortical neurons and examine whether information about the stimulus is contained, not only in the relations between the amplitudes of the distributed neural responses, but also in the precise temporal relations between the individual discharges – relations that can be decoded e.g., by coincidence sensitive neurons. Our hypothesis is that the presence of gamma oscillations in the cortical network enhances the precision of temporal relations and thereby increases the amount of information about the stimulus encoded by assemblies of distributed neurons. The core assumption is that important computational processes occur only when the cortical network engages in gamma oscillations. Candidate processes are modulation of responses to local features by context, i.e., by interactions from regions outside the classical receptive field and by top-down effects from other cortical areas. The rationale behind this assumption is that long-range interactions require precisely synchronized activity to be effective and that precise synchrony is achieved through oscillatory patterning in the high-frequency range.

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Wolf Singer