PURPOSE To determine the light sensitivity of poorly reflective cones observed in retinas of normal subjects, and to establish a relationship between cone reflectivity and perceptual threshold. METHODS Five subjects (four male, one female) with normal vision were imaged longitudinally (7-26 imaging sessions, representing 82-896 days) using adaptive optics scanning laser ophthalmoscopy (AOSLO)...

The reliability of subjects' judgments of the groups present in dot patterns and the sensitivity of those judgments to stimulus transformation were assessed. The subjects indicated the groups that they saw within random dot patterns, and each judgment was compared with those of other subjects and with their own judgments for related presentations. Within subjects, each pattern appeared in an in...

Perception of dialect variation is well studied with respect to perceptual similarity of talkers based on dialectal markers. This study examines the perceptual distinctiveness of regional vowel variants in light of cross-generational changes in vowel productions. Listeners from two regional dialects of English identified the dialect of the speaker in monosyllabic words (produced by older adults...

Perceptual systems in all modalities are predominantly sensitive to stimulus change, and many examples of perceptual systems responding to change can be portrayed as instances of enhancing contrast. Multiple findings from perception experiments serve as evidence for spectral contrast explaining fundamental aspects of perception of coarticulated speech, and these findings are consistent with a b...

Recent findings suggest that children with autism may be impaired in the perception of biological motion from moving point-light displays. There have also been reports that some children with autism have abnormally high motion coherence thresholds. In the current study we tested a group of children with autism and a group of typically developing children aged 5 to 12 years of age on three diffe...

Perceptual acoustic echo cancellers were developed by mainly considering human hearing thresholds of different acoustic frequencies in the past. In addition to the different frequency sensitivities, the human brain further analyzes sounds in terms of their spectral and temporal modulations. In this paper, we extend the perceptual normalized least mean square (P-NLMS) algorithm by adding a secon...

We describe a perceptual experiment whose goal is to compare perceptual sensitivity to pitch accent contrasts in nuclear and prenuclear positions. The material consists of Czech sentences which have been resynthesized with controlled intonation. The results show that changes in nuclear pitch accents are perceived more sharply than changes in prenuclear pitch accents, and that the H* accent is p...

The detectability of an object in our visual environment is primarily determined by the object's low-level visual salience, resulting from the physical characteristics of the object and its surroundings. In the present study we demonstrate that object detectability is additionally influenced by internally generated expectations about object properties, and that these influences are mediated by ...

Pain catastrophizing is generally viewed as an important cognitive factor underlying chronic pain. The present study examined personality and temperament correlates of pain catastrophizing in a sample of young adolescents (N = 132). Participants completed the Pain Catastrophizing Scale for Children, as well as scales for measuring sensitivity of the behavioral inhibition and behavioral activati...

Attending to a stimulus enhances the sensitivity of perceptual decisions. However, it remains unclear how perceptual sensitivity varies according to whether a feature is expected or unexpected. Here, observers made fine discrimination judgments about the orientation of visual gratings embedded in low spatial-frequency noise, and psychophysical reverse correlation was used to estimate decision '...