scholarly journals Cortical activation associated with determination of depth order during transparent motion perception: A normalized integrative fMRI-MEG study

2015 ◽  
Vol 36 (10) ◽  
pp. 3922-3934 ◽  
Author(s):  
Hiroaki Natsukawa ◽  
Tetsuo Kobayashi
Keyword(s):  
Motion Perception ◽  
Cortical Activation ◽  
Depth Order ◽  
Transparent Motion

scholarly journals Psychophysical Tests Do Not Identify Ocular Dominance Consistently

i-Perception ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 204166951984139 ◽  
Author(s):  
Miguel A. García-Pérez ◽  
Eli Peli
Keyword(s):  
Clinical Practice ◽  
Motion Perception ◽  
Ocular Dominance ◽  
The Other ◽  
Threshold Test ◽  
Eye Dominance ◽  
Dominant Eye ◽  
Psychophysical Tests ◽  
Sensory Tests

Classical sighting or sensory tests are used in clinical practice to identify the dominant eye. Several psychophysical tests were recently proposed to quantify the magnitude of dominance but whether their results agree was never investigated. We addressed this question for the two most common psychophysical tests: The perceived-phase test, which measures the cyclopean appearance of dichoptically presented sinusoids of different phase, and the coherence-threshold test, which measures interocular differences in motion perception when signal and noise stimuli are presented dichoptically. We also checked for agreement with three classical tests (Worth 4-dot, Randot suppression, and Bagolini lenses). Psychophysical tests were administered in their conventional form and also using more dependable psychophysical methods. The results showed weak correlations between psychophysical measures of strength of dominance with inconsistent identification of the dominant eye across tests: Agreement on left-eye dominance, right-eye dominance, or nondominance by both tests occurred only for 11 of 40 observers (27.5%); the remaining 29 observers were classified differently by each test, including 14 cases (35%) of opposite classification (left-eye dominance by one test and right-eye dominance by the other). Classical tests also yielded conflicting results that did not agree well with classification based on psychophysical tests. The results are discussed in the context of determination of ocular dominance for clinical decisions.

scholarly journals Perceiving Animacy From Deformation and Translation

i-Perception ◽  
2017 ◽  
Vol 8 (3) ◽  
pp. 204166951770776 ◽  
Author(s):  
Takahiro Kawabe
Keyword(s):  
Motion Perception ◽  
Biological Motion ◽  
Critical Role ◽  
Vertical Motion ◽  
Motion Vectors ◽  
Biological Motion Perception ◽  
Translation Component ◽  
Point Light ◽  
Original Motion

In a cartoon, we often receive an animacy impression from a dynamic nonanimate object, such as a sponge or a flour sack, which does not have an animal-like shape. We hypothesize that the animacy impression of a nonanimal object could stem from dynamic patterns that are possibly fundamental for biological motion perception. Here we show that observers recognize the animacy of human jump actions from the combination of deformation and translation. We extracted vertical motion vectors from the uppermost and lowermost points in point-light jumper stimuli and assigned the vectors to a uniform rectangle. The participants’ task was to rate the animacy and jump impressions for the rectangle. Results showed that both animacy and jump impressions for the rectangle movements were comparable to those for the original point-light movements. The impressions decreased for stimuli having a deformation or translation component alone, which was extracted from the original motion vectors. By mathematically simulating deformation and translation in a human jump, we also found that the temporal relation between deformation and translation plays a critical role in the determination of jump impressions but only has a moderate effect for animacy impressions. On the basis of the results, we discuss how cartoon techniques take advantage of the properties of biological motion perception.

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