Bernal S D_2010.pdf - University of Plymouth

2.4. ORIGINAL CONTRIBUVONfi IN THIS CHAPTER
different feedback sources integrated? b) if one of the sources is inactivated (e.g. IT) are
the remaining regions sufficient to generate the subjective contour in VI ?
• Are illusory and occluded objects represented in high-level regions in a dirierent way to
complete objects? U' so, are they represented with their missing parts, or as complete
objects but with a watermark indicating they are occluded/illusory?
• For Kanizsa figures with ambiguously defined inducers, e.g. rounded comers, the illusory
contour is no longer perceived (based on psychophysical data). I.^J feedback equivalent
in Kanizsa figures with ambiguously vs. precisely defined inducers? Is the perceptual
difference due to the lack of local precise cues which prevents horizontal connections
from lorming the illusory contour? If the rounded comers were gradually transfomied
into siraighi comers, a) at what point would the illusory contour be perceived?, and b)
how would this correlate to the neural representation in V2 and VI?
• What neural processes are being activated when a human observer decides to voluntarily
change the perception of a Kanizsa ligure to that of individual pacmen? Is feedback
responsible for inhibiting the generation of the illusory contours?
2.4 Original contributions in this chapter
• Review evidence and identify key questions on the role of cortical high-level feedback in
object perception.
• Analyze and compare the different functional interpretations of feedback and identify
points of convergence between them.
• Review evidence and identify key questions on the representation in the visual system of
illusory and occluded contours.
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