1. Marisa Carrasco Psychology and Neural Science, NYU Psychology and Neural Science, NYU Marisa Carrasco Psychology and Neural Science, NYU Psychology and Neural Science, NYU Visual Attention

2. Introduction definition of the construct a bit of history Spatial attention and early vision contrast spatial resolution some experimental methods Feature based attention Visual search Attention Attention

3. Visual attention facilitation and selection of information overt attention – head and eye movements covert attention – monitor the environment inform eye movements spatial attention feature based attention

4. Publications on “Visual attention” Carrasco (Vision Research, 2011) Visual attention: The past 25 years

5. Publications on “Visual attention” Carrasco (Vision Research, 2011) Visual attention: The past 25 years

6. “Everyone knows what attention is. It is the taking possession by the mind, in clear and vivid form, of one out of what seem several simultaneously possible objects or trains of thought. Focalization, concentration, of consciousness are of its essence. It implies withdrawal from some things in order to deal effectively with others…” The Principles of Psychology The Principles of Psychology William James (1890) William James (1890)

7. Helmholtz on covert attention (1867) “It is a curious fact that the observer may be gazing steadily at the two pinholes and holding them in exact coincidence, and yet at the same time he can concentrate his attention on any part of the dark field he likes, so that when the spark comes, he will get an impression about objects in that particular region only. In this experiment the attention is entirely independent of the position and accommodation of the eyes, or indeed, of any known variations in or on the organ of vision. Thus it is possible, simply by a conscious and voluntary effort, to focus the attention on some definite spot in an absolutely dark and featureless field.” Physiological Optics, Vol, 3, p. 455. Thoemmes Press Ed.

8. Limited resources The high-energy cost of neuronal activity involved in cortical computation limits our ability to process information -constant overall energy consumption available to the brain -neuronal metabolic cost depends on the spike rate; the cost of a single spike is high -average discharge rate of active neurons determines how many neurons can be active concurrently […1%! ] The brain needs machinery for the system to allocate energy according to task demand… selective attention. Lennie, Current Bio ‘03

9. Capacity limitation As visual information traverses the successive cortical areas of the ventral visual stream, the size of receptive fields increase. Neurons in higher order areas with large receptive fields have to deal with many visual stimuli that appear simultaneously within their receptive fields.

11. Visual attention+

12. endogenous exogenous voluntaryinvoluntary controlled reflexive goal-drivenstimulus-driven sustained: 300 mstransient 80–20 ms Spatial covert attention

13. Attention – key role in perception 1980s and early 90s: necessary for effortful processing ‘glue’ that binds simple features into an object what attention does? what processes does it affect? last decade, effects of attention on perception: psychophysics single-unit recording neuroimaging

14. Posner’s paradigm Posner, Nissen, & Ogden (1978)

16. Campbell & Robson (68) Sensitivity (1 / Threshold ) Spatial Frequency (cpd) - + - + + Contrast

17. Attention enhances sensitivity Attention enhances sensitivity neutral peripheral 1 cpd 2 cpd 4 cpd8 cpd Carrasco, Penpeci & Eckstein, Vis.Res. 2000

18. Experimental trial Experimental trial

19. Pestilli & Carrasco, 2005 valid/neutralinvalid/neutral valid/neutral – invalid/neutral

20. Pestilli & Carrasco, JoV 07

23. adaptation

24. Exogenous attention and adaptation Attention: response gain ~ Ling & Carrasco, Vis. Res. 06 Adaptation: contrast gain Benefit and cost are similar regardless of adaptation state Attention overcomes adaptation and restores contrast sensitivity Pestilli & Carrasco, JoV 07

25. low high stimulus contrast Responses increase with contrast Responses increase with contrast

26. fMRI acquisition fMRI acquisition 5 participants 3T Siemens, Allegra Surface coil (Nova medical) 19 slices, perpendicular to calcarine sulcus Voxel size: 3X3X3 mm TR = 2 s, TE = 30 ms Liu, Pestilli & Carrasco, Neuron 2005

27. V1 V2 V3 V3A/B V7 hV4 LO1 LO2 V2 V3 V3A/B V7 hV4 LO2 LO1 Retinotopy and visual areas

28. dorsal medial separate cue/stimulus (ROI) separate cue/stimulus (ROI) size: 3° eccentricity: 6° separation: 1° contrast: 100%

29. Trial sequencefixationpoint invalid valid precue 50 ms 50 ms ISI 50 ms Time display 150 ms response 1750 ms Precue Trial orientation of the tilted Gabor ?

30. fixation point invalid valid precue 50 ms ISI 50 ms Time display 150 ms response 1750 ms invalidvalid Precue TrialPostcue Trial Trial sequence

31. Performance Performance n = 5 1 SEM Accuracy Reaction time (ms) * * Valid-precue Invalid-precue Valid-postcue Invalid-postcue

32. * ** BOLD time series BOLD time series Valid-precue Invalid-precue Valid-postcue Invalid-postcue distracter Error bars 1 s.e.m

33. Attention modulation index (AMI) Peak val-pre – Peak baseline Peak val-pre + Peak baseline AMI =

34. an uninformative peripheral precue concurrently increases performance and retinotopically specific stimulus-evoked activity in early visual areas cueing effect increases gradually from V1 to V3a (feedback or feedforward?) Liu, Pestilli & Carrasco, Neuron 2005 a fMRI exogenous attention fMRI exogenous attention

35. Reynolds, Pasternak & Desimone, 2000 Single unit recording

36. YES. Wundt, Mach, Helmholtz & Titchener W. James NO. Fechner Yes, but it does not ever lead us astray Does attention intensify the sensory representation?

37. - non-predictive peripheral cue - 2 x 2 AFC task: orientation contingent on apparent contrast..... fixation point 500 ms cue 67 ms ISI 53 ms stimuli 40 ms response 1 s neutral cue peripheral cue Methods Methods “what is the orientation of the higher contrast stimulus?”

38. 1 10 SOA - 500 ms 100 n = 16 1 10 0 50 100 n = 16 100 % perceived contrast: Test > Standard Test cued Neutral cue Standard cued Contrast appearance SOA - 100 ms Contrast of test stimulus

39. Attention alters contrast appearance Test Cued Neutral Standard Cued 16%22%28% Carrasco, Ling & Read Nature Neurosci, 2004

40. Liu, Abrams & Carrasco, Psych.Sci. 2009 Endogenous attention

41. Liu, Abrams & Carrasco, Psych.Sci. 2009 Attention affects RSVP performance

42. Liu, Abrams & Carrasco, Psych.Sci. 2009

43. Attention & appearance contrast Carrasco, Ling & Read, 2004; Liu, Abrams & Carrasco, 2009, Anton-Erxleben, Abrams & Carrasco 2011 spatial frequency Goebell & Carrasco, 2005 Abrams, Barbot & Cattasco, 2011 apparent size Anton-Erxleben & Treue, 2007 motion coherence Liu, Fuller & Carrasco, 2006 flicker Montagna & Carrasco, 2006 speed Turatto et al., 2007; Anton-Erxleben, Herrmann & Carrasco, 2013 saturation, not hue Fuller & Carrasco, 2006