B04 until 12/2013
About project B04 (completed 12/2013)
Project title: Functional role of adaptation and neural noise for population coding
Summary: Representing a stimulus by a population of neurons makes activity correlations between neurons available as an additional coding dimension. We want to explore in general how sensory stimuli can be represented by populations of independent neurons. Within the project we first focused on the information carried by synchronous spikes about a common stimulus in contrast to the information carried by all spikes. In a collaboration with Benjamin Lindner, HU Berlin, we tackled this problem analytically (Sharafi et al., 2013). This project was driven by our experimental data from the electrosensory system of weakly electric fish.
In addition to intrinsic noise, arising for example from channel noise, a major source of (static) noise in a neural population is its heterogeneity. A special but nevertheless common case of heterogeneity are receptor neurons that differ mainly in their sensitivity with respect to a sensory stimulus. Often higher order neurons receiving input from such a population show steep response curves that can be shifted by adaptation to the mean intensity of the stimulus. How information from such a population of receptor neurons is integrated to generate such response profiles, and in which way adaptation mechanisms play a role, has not been investigated yet. In our second line of research we developed and analyzed different models.