2nd tac meeting
Download
1 / 23

2nd TAC Meeting - PowerPoint PPT Presentation


  • 65 Views
  • Uploaded on

2nd TAC Meeting. Neuronal Coding in the Retina and Fixational Eye Movements. Christian B. Mendl Tim Gollisch Lab. April 22, 2010. Outline. Review of last TAC meeting Informative spike response features Latency coding by cell pairs Modeling response features Outlook.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' 2nd TAC Meeting' - zasha


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
2nd tac meeting

2nd TAC Meeting

Neuronal Coding in the Retina

and Fixational Eye Movements

Christian B. Mendl

Tim Gollisch Lab

April 22, 2010


Outline
Outline

  • Review of last TAC meeting

  • Informative spike response features

  • Latency coding by cell pairs

  • Modeling response features

  • Outlook


Review of last tac meeting
Review of Last TAC Meeting

  • Fixational eye movements, microsaccades

  • Counteract visual perception fading

  • Enhancement of spatial resolution

  • Last TAC meeting: information theory: mutual information, synergy → use as screening tool

  • To-do:

    • stimulus variation: grating instead of border

    • neuronal model building

    • decoding strategies


Informative spike response features
Informative Spike Response Features

Observed spike responses of a single cell



Informative spike features cont
Informative Spike Features (cont)

Observed spike responses of a single cell


Informative spike responses number of spikes trial
Informative Spike Responses:Number of Spikes/Trial


Informative spike responses internal structure
Informative Spike Responses:Internal Structure

ISI (inter-spike-interval)



Latency coding by cell pairs
Latency Coding by Cell Pairs

  • Latency emerges as most informative spike response feature

  • Timing reference? (Brain doesn’t know stimulus onset)

  • → Need several cells


Cell pairs experimental data
Cell Pairs: Experimental Data


Relative latency
Relative Latency

time intervals accessible to readout by higher brain regions


Cell pairs latency scatter plot
Cell Pairs: Latency Scatter Plot

K-means clustering: relative weight of off-diagonal elements:

19.1%



Drift corrected latency scatter plot
Drift-Corrected Latency Scatter Plot

K-means clustering:

relative weight of

off-diagonal elements:

9.6%


Latency correlations
Latency Correlations

  • Observation: global latency drift leads to (artificial) correlations, can correct for that

  • Question: cells internally interacting on short-term scale?

  • → Compare spikes shuffled by one trial


Latency correlations cont
Latency Correlations (cont)

shuffled version: no correlations


Latency c orrelation statistics
Latency Correlation Statistics


Conclusions latency coding
Conclusions Latency Coding

  • Use latency instead of spike count and inter-spike-interval

  • High information content in latency data from two cells

  • Correlations might improve coding




Conclusions modeling
Conclusions Modeling

  • Qualitative agreement

  • But still much room for improvement, latency data on 10 ms scale not reproduced

  • Gain control might be able to reproduce experimental spike histogram


Outlook
Outlook

  • Fixational eye movements have been reported in Salamander

  • But precise quantification still missing

  • → Search coil setup


ad