Cognitive Neuroscience Talks

Markers of Excitatory-Inhibitory Balance Related to the Processing of Sounds

For conscious perceptions to emerge synchronization of neuronal activity has to take place at a local (e.g. sensory cortex) level as well as over longer distances. It is now well known that synchronized brain activity is frequently "expressed" in form of oscillations, with different frequency bands reflecting different levels of excitation / excitability. The excitatory-inhibitory balance is known to be a) deviant in various pathologies, b) fluctuate spontaneously in healthy participants and c) alterable by cognitive mechanisms such as attention. My group studies all three processes in the auditory modality, for which far less in known than e.g. the visual system. In the first part of the talk I will present current studies that investigate how attention / expectations modulate oscillatory brain activity related to the processing of sounds in normal hearing subjects. The second part of the talk will focus on deviances of oscillatory brain activity in tinnitus, the conscious perception of a sound thought to emerge from intrinsic brain activity. In the last part of my presentation, I would like to show preliminary results from our efforts to modify the excitatory-inhibitory balance in auditory cortex by means of TMS.