The Problems With Time Neuroenigmas Lecture January 19, 2007
Neural processing is not instantaneous
40 ms Neural processing is not instantaneous
40 ms 100 ms Neural processing is not instantaneous
When is this a problem?
100 mph fast ball moves 15 feet in 100 ms
How might we compensate for neural delays?
Sensory compensation Motor compensation
Theories to explain flash-lag effect Motion extrapolation Motion integration and post diction Latency differences for moving and stationary items Attentional capture by flashed item Citation for review
Flag errors in soccer games: the flash-lag effect brought to real life Perception, 2002, volume 31, pages 1205 ^ 1210 Marcus Vinicius C Baldo, Ronald D Ranvaud, Edgard Morya DOI: /p3422
Psychophysics +
Psychophysics Isolated Flash Subject JD Position (deg) Proportion reported right
Psychophysics Isolated Flash Subject JD Position (deg) Proportion reported right
Psychophysics +
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Psychophysics Flash in motion Subject JD Position (deg) Proportion reported right
Psychophysics Flash in motion Subject JD Position (deg) Proportion reported right o
Physiology
Tootell, R. B., M. S. Silverman, et al. Science (1982) Retinotopy in cat
Prediction: Under conditions that give rise to the perceived shift, receptive fields should shift in a direction opposite to motion direction.
RF Physiology
RF Physiology
RF Physiology flash positions
RF Physiology flash positions
Physiology Time (ms) firing rate
Physiology Time (ms) firing rate
Physiology Time (ms) firing rate
Physiology Time (ms) firing rate
Physiology Time (ms) firing rate
Physiology Time (ms) firing rate
Physiology Time (ms) firing rate
Physiology Time (ms) firing rate
Physiology Time (ms) firing rate
Physiology Time (ms) firing rate
Physiology Time (ms) firing rate
Physiology Time (ms) firing rate
Physiology Time (ms) firing rate
Physiology Time (ms) firing rate
Physiology Time (ms) firing rate
Physiology Time (ms) firing rate Position (deg) right left baseline
Physiology Time (ms) firing rate firing rate Position (deg) right left baseline
Physiology Time (ms) firing rate firing rate Position (deg) right left baseline
Physiology firing rate Position (deg) right left baseline
Physiology firing rate Position (deg) right left baseline
Physiology o firing rate Position (deg) right left baseline
flash positions RF Physiology
firing rate Position (deg)
Physiology firing rate Position (deg)
Physiology * * ** * * * Inward Outward firing rate Position (deg)
Physiology * * * * * ** * * * * Inward Outward firing rate Position (deg)
Physiology * * * * * ** * * * * Shift Index = 1.2 o Inward Outward firing rate Position (deg)
Example cell Physiology firing rate position (deg) firing rate position (deg) firing rate position (deg) firing rate position (deg) * ** * * * * * * * * * ** * * * * * * * * * * * * * S.I. = 1.2 o S.I. = 0.4 o S.I. = 0.8 o
Physiology Mean S.I. =.31 o p <.0001 n = 59 number of cells Position (deg)
Physiology Full Motion sequence Mean S.I. =.31 o p <.0001 n = 59 number of cells Position (deg)
Physiology Full Motion sequence Shift across population =.31 o p <.0001
Physiology Full Motion sequence Shift across population =.31 o p <.0001 Flash Terminal sequence
Physiology Full Motion sequence Shift across population =.31 o p <.0001 Flash Terminal sequence Shift across population =.34 o p <.0001
Physiology Full Motion sequence Shift across population =.31 o p <.0001 Flash Terminal sequence Shift across population =.34 o p <.0001 Single Color sequence
Physiology Full Motion sequence Shift across population =.31 o p <.0001 Flash Terminal sequence Shift across population =.34 o p <.0001 Single Color sequence Shift across population =.12 o p =.14
Physiology Non-Color Selective Cells Similar results to full population
Summary
Spatial representation of the the flashed element is distorted
Summary Spatial representation of the the flashed element is distorted Apparent in the first responses
Summary Spatial representation of the the flashed element is distorted Apparent in the first responses Similar in magnitude to mislocalization in humans
Summary Spatial representation of the the flashed element is distorted Apparent in the first responses Similar in magnitude to mislocalization in humans Motion alone is not sufficient to induce shift
Summary Spatial representation of the the flashed element is distorted Apparent in the first responses Similar in magnitude to mislocalization in humans Motion alone is not sufficient to induce shift Dissociation between perception and V4 physiology in the flashed terminal condition
Summary Spatial representation of the the flashed element is distorted Apparent in the first responses Similar in magnitude to mislocalization in humans Motion alone is not sufficient to induce shift Dissociation between perception and V4 physiology in the flashed terminal condition V4 distortion does not require motion following the flash
Probability Position Full motion condition Flash terminal condition
Bhavin R. Sheth, Romi Nijhawan, & Shinsuke Shimojo. (2000). Changing objects lead briefly flashed ones. Nature Neuroscience 3,
David Alais & David Burr. (2003). The flash-lag effect occurs in audition and crossmodally. Current Biology 13,
R.H. Cai, K. Jacobson, R. Baloh, M. Schlag-Rey & J. Schlag. (2000) Vestibular signals can distort the perceived spatial relationship of retinal stimuli. Experimental Brain Research 135,
Alan Johnston & Shinya Nishida (2001). “Time perception: brain time or event time. Current Biology 11, R427-R430. K. Moutoussis and S. Zeki, Functional segregation and temporal hierarchy of the visual perceptive systems. Proc R Soc Lond [Biol] Biol Sci 264 (1997), pp. 1407– Color Motion Asynchrony Illusion