We propose a novel approach to study the mechanisms underlying integration and segmentation in motion perception. This problem is central to motion processing, and it can also be used as a model for how the brain computes a global percept from many isolated local cues in other domains of vision. There has been previous research on this topic with stimuli such as plaids and random-dot displays, using brief-duration presentations. We will approach the problem in a novel way by focusing on the dynamics of perceptual alternations during long presentations of ambiguous motion displays. Such stimuli can evoke the perception of either motion integration long (""""""""coherency"""""""") or segmentation (""""""""transparency""""""""). At long presentations, perception alternates between coherency and transparency; it is bi-stable. Our Preliminary Results show that the dynamics approach provides more sensitive measures of the relative strength of segmentation versus integration than brief-presentation methods. Importantly, it allows to measure the strength of the two processes independently. We have already revealed a wealth of new information about the mechanisms of coherency and transparency and the interplay between them. Our approach offers more than just methodological advantages. It will provide an invaluable set of data for testing and further developing models for how the brain resolves the competition between motion coherency and segmentation. Furthermore, expanding the dynamics approach - at present restricted mostly to binocular rivalry - to another domain in vision will be an important step towards understanding general principles underlying competition and cooperation between different brain states. In the work proposed here, we have five specific aims: (I) to apply a new dynamic method we have developed, RTtransp, which provides a better measure of the relative strength of integration and segmentation, to test the effect of motion parameters over much wider ranges than had been possible so far. (II) to validate the dynamic method of Durations of Alternating Percepts (DAP) as a way of measuring the strength of two competing percepts independently; DAP has been extensively used in binocular rivalry but its validity in the motion domains needs further testing. (III) to use DAP to check how motion parameters that are known to affect the relative strength of motion segmentation and integration affect each of those processes independently. (IV) to use DAP to study the effect of static form cues for surface segmentation on the interplay between the segmentation and integration mechanisms in motion. (V) to use fMRI to relate our results to the physiological processes underlying motion integration/segmentation

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY014030-03
Application #
6752810
Study Section
Visual Sciences B Study Section (VISB)
Program Officer
Oberdorfer, Michael
Project Start
2002-06-01
Project End
2006-05-31
Budget Start
2004-06-01
Budget End
2006-05-31
Support Year
3
Fiscal Year
2004
Total Cost
$221,907
Indirect Cost
Name
New York University
Department
Neurology
Type
Schools of Arts and Sciences
DUNS #
041968306
City
New York
State
NY
Country
United States
Zip Code
10012
Lerner, Yulia; Singer, Neomi; Gonen, Tal et al. (2012) Feeling without seeing? Engagement of ventral, but not dorsal, amygdala during unaware exposure to emotional faces. J Cogn Neurosci 24:531-42
Ludmer, Rachel; Dudai, Yadin; Rubin, Nava (2011) Uncovering camouflage: amygdala activation predicts long-term memory of induced perceptual insight. Neuron 69:1002-14
Vessel, Edward A; Rubin, Nava (2010) Beauty and the beholder: highly individual taste for abstract, but not real-world images. J Vis 10:18.1-14
Moreno-Bote, Ruben; Shpiro, Asya; Rinzel, John et al. (2010) Alternation rate in perceptual bistability is maximal at and symmetric around equi-dominance. J Vis 10:1
Shpiro, Asya; Moreno-Bote, Ruben; Rubin, Nava et al. (2009) Balance between noise and adaptation in competition models of perceptual bistability. J Comput Neurosci 27:37-54
Moreno-Bote, Ruben; Shpiro, Asya; Rinzel, John et al. (2008) Bi-stable depth ordering of superimposed moving gratings. J Vis 8:20.1-13
Hasson, Uri; Yang, Eunice; Vallines, Ignacio et al. (2008) A hierarchy of temporal receptive windows in human cortex. J Neurosci 28:2539-50
Curtu, Rodica; Shpiro, Asya; Rubin, Nava et al. (2008) Mechanisms for Frequency Control in Neuronal Competition Models. SIAM J Appl Dyn Syst 7:609-649
Moreno-Bote, Ruben; Rinzel, John; Rubin, Nava (2007) Noise-induced alternations in an attractor network model of perceptual bistability. J Neurophysiol 98:1125-39
Shpiro, Asya; Curtu, Rodica; Rinzel, John et al. (2007) Dynamical characteristics common to neuronal competition models. J Neurophysiol 97:462-73

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