Perceptual asynchrony

Perceptual asynchrony refers to the phenomenon of two simultaneously presented attributes of the visual world being perceived by humans asynchronously instead of simultaneously.[1]

Perceptual asynchrony was first demonstrated by Konstantinos Moutoussis and Semir Zeki in 1997.[1] In their work, Moutoussis and Zeki describe that people perceive the color and direction of motion of a visual stimulus with a time lag - they may perceive the color before the direction of motion. They quantified this time gap to be between 70 – 80 milliseconds.

Description

The experiments through which perceptual asynchrony was derived were pairing experiments in which subjects are asked to determine the color and direction of a single stimulus that is moving up and down (or right and left) and changing its color from, say red to green, while doing so – the change in the color and direction of motion being in and out of phase with respect to each other.

There are several variants of this experiment, all leading to the same result.[2][3][4][5][6][7] The asynchrony extends to the simultaneously presented color and orientation of lines, when it is found that the color is perceived before the orientation by about 40 milliseconds. The degree of perceptual asynchrony can be considerably reduced by manipulating the stimuli in a variety of ways,[8][9][10] which has led to the suggestion that the asynchrony is the result of differences in processing times taken to bring different attributes to a perceptual level.

The demonstration has far-reaching consequences because it shows

  • that two attributes, presented simultaneously in terms of physical reality, are not perceived simultaneously but asynchronously;
  • that, as a result, the brain incorrectly binds the two presented attributes, in other words that it binds an attribute perceived at one moment with the other attribute that had been perceived some 40 to 80 ms earlier;
  • that, consequently, there is no brain system or area that “waits” for all visual attributes to be brought up to a perceptual level before binding them together to give a percept in which the two attributes are seen in perfect registration.

The demonstration has consequences for understanding neural binding and consciousness and has led to the theory of Micro-Consciousness.[11]

Confirmation

Perceptual asynchrony has been confirmed in many laboratories. It has also been shown it depends on the asynchronous perception of attributes rather than the perception of changes. If in a similar color - direction of motion pairing experiment, subjects are asked when a change in the two attributes occurred, without reporting the colour or direction of motion of the attribute, there is no perceptual asynchrony.[12] Whether an asynchrony is observed or not depends, therefore, on the task.[13]

Perceptual asynchrony has been accounted for by supposing that visual properties such as color, direction of motion and orientation of lines are processed at different speeds and therefore brought to perceptual completion at different times.[14][15][16] Other interpretations to account for this perceptual asynchrony have been given but, in essence, these are also based on differences in processing times. One such interpretation posits that there is a brain ‘time marker’ [17] while another posits that the asynchrony can be accounted for by positing that access to brain color “transients” is stronger than that to motion “transients”.[13]

References
  1. Moutoussis K, Zeki S (March 1997). "A direct demonstration of perceptual asynchrony in vision". Proceedings. Biological Sciences. 264 (1380): 393–9. Bibcode:1997RSPSB.264..393M. doi:10.1098/rspb.1997.0056. PMC 1688275. PMID 9107055.
  2. Moutoussis K, Zeki S (October 1997). "Functional segregation and temporal hierarchy of the visual perceptive systems". Proceedings. Biological Sciences. 264 (1387): 1407–14. Bibcode:1997RSPSB.264.1407M. doi:10.1098/rspb.1997.0196. PMC 1688701. PMID 9364780.
  3. Zeki S, Moutoussis K (October 1997). "Temporal hierarchy of the visual perceptive systems in the Mondrian world". Proceedings. Biological Sciences. 264 (1387): 1415–9. Bibcode:1997RSPSB.264.1415Z. doi:10.1098/rspb.1997.0197. PMC 1688708. PMID 9364781.
  4. Arnold DH, Clifford CW, Wenderoth P (April 2001). "Asynchronous processing in vision: color leads motion". Current Biology. 11 (8): 596–600. doi:10.1016/s0960-9822(01)00156-7. PMID 11369204. S2CID 3150786.
  5. Linares D, López-Moliner J (August 2006). "Perceptual asynchrony between color and motion with a single direction change". Journal of Vision. 6 (9): 974–81. doi:10.1167/6.9.10. PMID 17083289.
  6. Viviani P, Aymoz C (October 2001). "Colour, form, and movement are not perceived simultaneously". Vision Research. 41 (22): 2909–18. doi:10.1016/S0042-6989(01)00160-2. PMID 11701183. S2CID 17176776.
  7. Self E (2014-11-01). "Color–motion asynchrony assessed along the chromatic axes and with luminance variation". Attention, Perception, & Psychophysics. 76 (8): 2184–2188. doi:10.3758/s13414-014-0773-5. ISSN 1943-393X.
  8. Arnold DH, Clifford CW (March 2002). "Determinants of asynchronous processing in vision". Proceedings. Biological Sciences. 269 (1491): 579–83. doi:10.1098/rspb.2001.1913. PMC 1690936. PMID 11916473.
  9. Holcombe AO (2009-01-01). "Temporal binding favours the early phase of colour changes, but not of motion changes, yielding the colour–motion asynchrony illusion". Visual Cognition. 17 (1–2): 232–253. doi:10.1080/13506280802340653. ISSN 1350-6285.
  10. Lo YT, Zeki S (2014). "Perceptual asynchrony for motion". Frontiers in Human Neuroscience. 8: 108. doi:10.3389/fnhum.2014.00108. PMC 3941194. PMID 24624071.
  11. Zeki S (2007). A Theory of Micro-Consciousness. The Blackwell Companion to Consciousness. John Wiley & Sons, Ltd. pp. 580–588. doi:10.1002/9780470751466.ch46. ISBN 978-0-470-75146-6.
  12. Bedell HE, Chung ST, Ogmen H, Patel SS (October 2003). "Color and motion: which is the tortoise and which is the hare?". Vision Research. 43 (23): 2403–12. doi:10.1016/S0042-6989(03)00436-X. PMID 12972391. S2CID 2146151.
  13. Holcombe AO, Cavanagh P (May 2008). "Independent, synchronous access to color and motion features". Cognition. 107 (2): 552–80. doi:10.1016/j.cognition.2007.11.006. PMC 2766571. PMID 18206865.
  14. Arnold DH, Clifford CW (March 2002). "Determinants of asynchronous processing in vision". Proceedings. Biological Sciences. 269 (1491): 579–83. doi:10.1098/rspb.2001.1913. PMC 1690936. PMID 11916473.
  15. Yazdanbakhsh A, Nishina S, Watanabe T (2010-03-24). "Perceptual asynchrony between sinusoidally modulated luminance and depth". Journal of Vision. 9 (8): 54–54. doi:10.1167/9.8.54. ISSN 1534-7362.
  16. Žaric G, Yazdanbakhsh A, Nishina S, De Weerd P, Watanabe T (2015-11-25). "Perceived temporal asynchrony between sinusoidally modulated luminance and depth". Journal of Vision. 15 (15): 13. doi:10.1167/15.15.13. PMC 5079707. PMID 26605842.
  17. Nishida S, Johnston A (March 2002). "Marker correspondence, not processing latency, determines temporal binding of visual attributes". Current Biology. 12 (5): 359–68. doi:10.1016/s0960-9822(02)00698-x. PMID 11882286. S2CID 6587832.
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