Discrimination of speed in 5-year-olds and adults: Are children up to speed?

Ahmed, Irshad; Lewis, Terri L.; Ellemberg, Dave; Maurer, Daphne

doi:10.1016/j.visres.2005.01.036

Cited by 34 publications

(29 citation statements)

References 37 publications

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“…This study investigated the speed discrimination and motion coherence thresholds of children with ASC aged 7 to 14 years and age-and ability-matched TD children for slow (1.5 deg/sec) and fast (6 deg/sec) conditions. Consistent with previous childhood studies of speed discrimination [Ahmed et al, 2005;Manning et al, 2012] and motion coherence [Ellemberg et al, 2004;Hadad, Maurer, & Lewis, 2011], thresholds varied with speed condition for all children, with greater sensitivities to fast than slow stimuli.…”

Section: Discussionsupporting

confidence: 87%

“…Thompson, Brooks, & Hammett, 2006, see review by Burr & Thompson, 2011]. These speed-tuned systems appear to follow different developmental trajectories with sensitivity for a slow reference speed (1.5 deg/sec) developing more gradually and maturing later than sensitivity for a fast reference speed (6 deg/sec) [Manning, Aagten-Murphy, & Pellicano, 2012, see also Ahmed, Lewis, Ellemberg, & Maurer, 2005;Hayward, Truong, Partanen, & Giaschi, 2011].…”

Section: Introductionmentioning

confidence: 99%

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Processing Slow and Fast Motion in Children With Autism Spectrum Conditions

2013

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Consistent with the dorsal stream hypothesis, difficulties processing dynamic information have previously been reported in individuals with autism spectrum conditions (ASC). However, no research has systematically compared motion processing abilities for slow and fast speeds. Here, we measured speed discrimination thresholds and motion coherence thresholds in slow (1.5 deg/sec) and fast (6 deg/sec) speed conditions in children with an ASC aged 7 to 14 years, and age- and ability-matched typically developing children. Unexpectedly, children with ASC were as sensitive as typically developing children to differences in speed at both slow and fast reference speeds. Yet, elevated motion coherence thresholds were found in children with ASC, but in the slow stimulus speed condition only. Rather than having pervasive difficulties in motion processing, as predicted by the dorsal stream hypothesis, these results suggest that children with ASC have a selective difficulty in extracting coherent motion information specifically at slow speeds. Understanding the effects of stimulus parameters such as stimulus speed will be important for resolving discrepancies between previous studies examining motion coherence thresholds in ASC and also for refining theoretical models of altered autistic perception.

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Section: Discussionsupporting

confidence: 87%

Section: Introductionmentioning

confidence: 99%

Processing Slow and Fast Motion in Children With Autism Spectrum Conditions

2013

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“…Heinrich, van der Smagt, Bach & Hoffmann, 2004; van de Grind, van Hof, van der Smagt & Verstraten, 2001). In children, different developmental patterns have been found for slower and faster speeds (Ahmed, Lewis, Ellemberg & Maurer, 2005); however, these differences were obtained in tasks where the slower motion was below the 2° s −1 cut‐off for optimal responding of MT/MST neurons (Britten et al ., 1993). Here we aimed to look at developmental trends for global motion by contrasting two speeds both within the optimal range for MT/MST neurons, that is, above 2° s −1 .…”

Section: Introductionmentioning

confidence: 99%

Long trajectory for the development of sensitivity to global and biological motion

Hadad

Maurer

Lewis

2011

Developmental Science

133

100

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We used a staircase procedure to test sensitivity to (1) global motion in random-dot kinematograms moving at 4° and 18° s(-1) and (2) biological motion. Thresholds were defined as (1) the minimum percentage of signal dots (i.e. the maximum percentage of noise dots) necessary for accurate discrimination of upward versus downward motion or (2) the maximum percentage of noise dots tolerated for accurate discrimination of biological from non-biological motion. Subjects were adults and children aged 6-8, 9-11, and 12-14 years (n = 20 per group). Contrary to earlier research, results revealed a similar, long developmental trajectory for sensitivity to global motion at both slower and faster speeds and for biological motion. Thresholds for all three tasks improved monotonically between 6 and 14 years of age, at which point they were adult-like. The results suggest that the extrastriate mechanisms that integrate local motion cues over time and space take many years to mature.

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“…However, with regard to speed discrimination during infancy and childhood, previous works suggest a differentiation between discrimination of slow and fast speeds (e.g., Ahmed, Lewis, Ellemberg, & Maurer, 2005;Dannemiller & Freedland, 1991). In particular, Dannemiller and Freedland (1991) presented 5-month-old infants with two bars moving at different speeds and measured infants' looking behavior to these displays.…”

Section: Introductionmentioning

confidence: 99%