Faculty Opinions recommendation of Circadian fluctuations in glucocorticoid level predict perceptual discrimination sensitivity.

Abstract Some researchers have argued that normal human observers can exhibit “blindsight-like” behavior: the ability to discriminate or identify a stimulus without being aware of it. However, we recently used a bias-free task to show that what looks like blindsight may in fact be an artifact of typical experimental paradigms’ susceptibility to response bias. While those findings challenge previous reports of blindsight in normal observers, they do not rule out the possibility that different stimuli or techniques could still reveal perception without awareness. One intriguing candidate is emotion processing, since processing of emotional stimuli (e.g. fearful/happy faces) has been reported to potentially bypass conscious visual circuits. Here we used the bias-free blindsight paradigm to investigate whether emotion processing might reveal “featural blindsight,” i.e. ability to identify a face’s emotion without introspective access to the task-relevant features that led to the discrimination decision. However, we saw no evidence for emotion processing “featural blindsight”: as before, whenever participants could identify a face’s emotion they displayed introspective access to the task-relevant features, matching predictions of a Bayesian ideal observer. These results add to the growing body of evidence that perceptual discrimination ability without introspective access may not be possible for neurologically intact observers.

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Modeling perceptual discrimination in dynamic noise: Time-changed diffusion and release from inhibition

Journal of Mathematical Psychology ◽

10.1016/j.jmp.2013.05.007 ◽

2014 ◽

Vol 59 ◽

pp. 95-113 ◽

Cited By ~ 21

Author(s):

Philip L. Smith ◽

Roger Ratcliff ◽

David K. Sewell

Keyword(s):

Perceptual Discrimination ◽

Dynamic Noise

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Performance Characteristics and Accuracy in Perceptual Discrimination of Leather and Synthetic Basketballs

Perceptual and Motor Skills ◽

10.2466/pms.1982.55.1.128 ◽

1982 ◽

Vol 55 (1) ◽

pp. 128-130 ◽

Cited By ~ 4

Author(s):

Sharon Mathes ◽

Kay Flatten

Keyword(s):

Analysis Of Variance ◽

Performance Characteristics ◽

Perceptual Discrimination ◽

Treatment Conditions ◽

Significant Difference ◽

Chi Squared ◽

Perceptual Mode

Performance characteristics of leather and synthetic basketballs were examined by measuring the basketballs' rebound heights on five types of playing surfaces (Tartan, asphalt, glass, concrete, hardwood). Comparing the basketballs' performance on the basis of their coefficients of restitution (e = height of rebound/height of drop) analysis of variance showed that the leather basketball rebounded significantly higher than the synthetic basketball on all surfaces. To assess the capability of individuals to discriminate perceptually between the balls 30 male and 30 female undergraduates were asked to determine whether basketballs randomly presented 20 times under four different treatment conditions (visual, tactual-kinesthetic static, tactual-kinesthetic dynamic, auditory) were leather or synthetic. Chi squared analysis of their accuracy across all four perceptual modes showed no significant difference. However, analysis by perceptual mode did produce significant differences, indicating subjects were more accurate in identification in the tactual-kinesthetic dynamic and static modes than in the visual and auditory.

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