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Sloan-Swartz Summer Meeting 2007

Attentional modulation of feature selectivity in area V4 James Mazer Department of Neurobiology Yale School of Medicine. Sloan-Swartz Summer Meeting 2007. What is feature attention?. Feature-based attention: attention directed towards a particular value along some stimulus dimension

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Sloan-Swartz Summer Meeting 2007

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  1. Attentional modulation of feature selectivity in area V4James MazerDepartment of NeurobiologyYale School of Medicine Sloan-Swartz Summer Meeting 2007

  2. What is feature attention? • Feature-based attention: attention directed towards a particular value along some stimulus dimension • in contrast to... • attention to a particular region of space (space-based) • attention to a particular visual “channel” or feature dimension

  3. Why study feature attention? • natural visual environments are cluttered • during natural vision we often know what we want, even when we don’t know where it is • feature attention, like spatial attention, can provide some resolution of limited neural bandwidth or capacity problems

  4. How do we study feature attention? Where’s Waldo? Visual Search

  5. V2 V1 V4 IT Extrastriate area V4

  6. IT/PFC LGN V1 V2 Salience maps & visual search V4

  7. IT/PFC oculomotor LGN V1 V2 Salience maps & visual search V4

  8. non-match (2-5s)hold bar delay (2-4s)hold bar sample (2-4s)grab bar match (2-5s)release bar Feeviewing visual search task

  9. Feeviewing visual search task

  10. Freeviewing visual search behavior

  11. baseline response gain response tuning shift response Modeling attentional effects passive response stimulus dimension

  12. Freeviewing reverse correlation single fixation eyeposition eyevelocity spikes  time 

  13. stimulus waveform + spikes … … Freeviewing reverse correlation

  14. baseline response gain response tuning shift response Modeling attentional effects passive response stimulus dimension

  15. no modulation 15% D gain 49% Dshape 30% Freeviewing: summary of modulatory effects D baseline 30% n=105

  16. Freevewing: summary of modulatory effects pureDshape 2% 5% 6% no modulation 15% 17% 30% 9% 17% pureDgain pureDbaseline n=105

  17. Freeviewing reverse correlation tuning spatialfrequencydomain m0067 STRF proj’d into stim PCA space

  18. Tuning shift: matched filter search target tuning  A spatialdomain spatial frequencydomain spatialfrequencydomain m0067 STRF proj’d into stim PCA space

  19. Tuning shift: matched filter search target tuning  A  B  C  D spatialdomain spatial frequencydomain spatialfrequencydomain m0067 STRF proj’d into stim PCA space

  20. Tuning shift: unknown relationship to target target

  21. Summary • feature attention can alter (1) mean rate, (2) gain and (3) preferred stimuli in V4 • baseline, gain and selectivity modulations occur in all possible combinations • preference changes could facilitate target detection during visual search (but it’s not a simple matched filter). • maximal tuning modulation occurs in neurons with broadest orientation tuning

  22. Gallant Lab (UCB) Stephen David Acknowledgements Jon Touryan Monica Cano Vinas Julie Golomb Matt Krause Xiao-Jing Wang

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