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At least 721 records · Page 40Linked to original sources
PubMed2006

Embodied temporal perception of emotion.

The role of embodiment in the perception of the duration of emotional stimuli was investigated with a temporal bisection task. Previous research has shown that individuals overestimate the duration of emotional, compared with neutral, faces (S. Droit-Volet, S. Brunot, & P. M. Niedenthal, 2004). The authors tested a role for embodiment in this effect. Participants estimated the duration of angry, happy, and neutral faces by comparing them to 2 durations learned during a training phase. Experimental participants held a pen in their mouths so as to inhibit imitation of the faces, whereas control participants could imitate freely. Results revealed that participants overestimated the duration of emotional faces relative to the neutral faces only when imitation was possible. Implications for the role of embodiment in emotional perception are discussed.

Analysis of Variance↗
PubMed2002

The age deficit on photopic counterphase flicker: contrast, spatial frequency, and luminance effects.

This study evaluated the contribution of reduced contrast sensitivity and retinal illuminance to the age-related deficit on the temporal resolution of suprathreshold spatial stimuli. The discrimination of counterphase flicker was measured in optimally refracted young and elderly observers for sinusoidal gratings of three spatial frequencies (1, 4, and 8 cycles per degree) at three contrast levels (0.11, 0.33, and 0.66). Age deficits in flicker discrimination at the two higher contrast levels and at the two lower spatial frequencies were unrelated to observer contrast sensitivity. Flicker discrimination of young observers who carried out the task through .5 ND filters to simulate a two-thirds reduction of retinal illuminance in the older eye, was similar to that of the elderly observers. An age-related reduction in retinal luminance appears to be a major determinant of the age-related spatiotemporal deficit at suprathreshold contrast levels, although neural factors may also be involved.

Adolescent↗
PubMed2004

Planning and control of straight-ahead and angled planar movements in adults and young children.

In the present study we wanted to determine why straight-ahead movements performed along one's mid-line are directionally more accurate than movements toward eccentric targets. We also wanted to determine whether the processes underlying this difference were the same in young children as in adults. Six-to-seven-year-old children and adults practiced a video-aiming task using different starting base and target combinations without vision of their ongoing movements. The results indicated that adults and children were directionally more accurate and less variable when pointing toward targets located straight ahead of the starting base rather than eccentric or concentric targets. This was true, regardless of whether the movement was performed along one's midline or not. These results suggest that angled movements are directionally less accurate than straight-ahead movements because of difficulty in defining the orientation of the appropriate movement vector in the workspace and/or in transforming it into appropriate motor commands. A kinematic analysis revealed large coefficients of direction and of extent variability early after movement initiation. However, these coefficients of variability were largely reduced by the occurrence of peak extent velocity, revealing that noise in initial movement planning was quickly reduced by on-line control processes. Finally, the results indicated largely similar planning and control processes for young children and adults.

Adult↗
PubMed1997

Spatio-temporal frequency domains and their relation to cytochrome oxidase staining in cat visual cortex.

Spatial and temporal frequencies are important attributes of the visual scene. It is a long-standing question whether these attributes are represented in a spatially organized way in cat primary visual cortex. Using optical imaging of intrinsic signals, we show here that grating stimuli of different spatial frequencies drifting at various speeds produce distinct activity patterns. Rather than observing a map of continuously changing spatial frequency preference across the cortical surface, we found only two distinct sets of domains, one preferring low spatial frequency and high speed, and the other high spatial frequency and low speed. We compared the arrangement of these spatio-temporal frequency domains with the cytochrome oxidase staining pattern, which, based on work in primate striate cortex, is thought to reflect the partition of the visual cortex into different processing streams. We found that the cytochrome oxidase blobs in cat striate cortex coincide with domains engaged in the processing of low spatial and high temporal frequency contents of the visual scene. Together with other recent results, our data suggest that spatiotemporal frequency domains are a manifestation of parallel streams in cat visual cortex, with distinct patterns of thalamic inputs and extrastriate projections.

Animals↗
PubMed2002

Across-frequency comparison of temporal speech information by listeners with normal and impaired hearing.

Listeners with normal hearing (NH) and with sensorineural hearing impairment (HI) were tested on a speech-recognition task requiring across-frequency integration of temporal speech information. Listeners with NH correctly identified a majority of key words in everyday sentences when presented with a synchronous pair of speech-modulated tones at 750 and 3,000 Hz. They could tolerate small amounts (12.5 ms) of across-frequency asynchrony, but performance fell as the delay between bands was increased to 100 ms. Listeners with HI performed more poorly than those with NH when presented with synchronous across-frequency information. Further, performance of listeners with HI fell as a function of asynchrony more steeply than that of their NH counterparts. These results suggest that listeners with HI have particular difficulty comparing and effectively processing temporal speech information at different frequencies. The increased influence of asynchrony indicates that these listeners are especially hindered by slight disruptions in across-frequency information, which implies a less robust comparison mechanism. The results could not be attributed to differences in signal or sensation level, or in listener age, but instead appear to be related to the degree of hearing loss. This across-frequency deficit is unlikely to be attributed to known processing difficulties and may exist in addition to other known disruptions.

Aged↗
PubMed1999

Do temporal processing deficits cause phonological processing problems?

This study tested the hypothesis that temporal processing deficits underlie phonological processing problems. The subjects were children aged 8 to 10 years (N = 110) who were separated into 2 groups on the basis of whether their reading scores were normal or poor. As predicted by many earlier studies, children with poor reading scores demonstrate poor abilities on tests of phonological awareness, as well as on 2 other language tasks that depend on phonological processing. Two specific tests of the temporal processing hypothesis were conducted. Children in both groups were tested (a) on their abilities to recall sequences of nonspeech tones presented at various rates and (b) on their abilities to make phonetic decisions using brief and transitional properties of the speech signal, especially formant transitions (the purported "trouble spot" in the speech signal for children with phonological processing problems). The children with poor phonological processing abilities showed no special difficulty recalling rapidly presented nonspeech stimuli, and, in their phonetic decisions, they were able to use brief and transitional signal properties, including formant transitions, at least as well as other children. Therefore, no evidence was found to support the hypothesis that temporal processing deficits cause phonological processing problems.

Awareness↗