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The developmental trajectory of contrast sensitivity in autism spectrum disorder / Jacalyn GUY in Autism Research, 9-8 (August 2016)
[article]
Titre : The developmental trajectory of contrast sensitivity in autism spectrum disorder Type de document : Texte imprimé et/ou numérique Auteurs : Jacalyn GUY, Auteur ; Laurent MOTTRON, Auteur ; Claude BERTHIAUME, Auteur ; Armando BERTONE, Auteur Article en page(s) : p.866-878 Langues : Anglais (eng) Mots-clés : autism spectrum disorder low-level perception development spatial frequency contrast sensitivity Index. décimale : PER Périodiques Résumé : Autism Spectrum Disorder (ASD) is characterized by a detail-driven visual processing strategy, evidence for which has been based largely on cross-sectional studies in small participant groups of limited age ranges. It is therefore unknown when sensitivity to detailed information emerges and develops in ASD. Contrast sensitivity to sinusoidal gratings of different spatial frequencies (0.5, 1, 2, 4, and 8 cycles per degree (cpd)) was measured for 34 participants with ASD and 55 typically developing participants (aged 6–16 years). Cross-sectional, developmental trajectories were constructed to examine within and between group differences across the range of spatial frequencies tested. Developmental trajectories indicated that sensitivity across low (i.e., 0.5 and 1 cpd) and mid (2 and 4 cpd) spatial frequencies varied by chronological age within each group, with mid frequencies developing at a more significant rate than low frequencies. There was no overall difference between groups in terms of the relationship of sensitivity and age across spatial frequencies, yet the ASD group had an overall lower level of sensitivity. Closer examination revealed that the youngest participants with ASD had a reduced sensitivity for mid frequencies. Moreover, the ASD group showed a statistically significant developmental relationship at 8 cpd, which suggests that a trend for increased sensitivity to early detailed information may manifest beyond the ages tested. These findings demonstrate a differential development of contrast sensitivity for spatial frequencies in ASD and underscore the need to better identify what drives such differences in the “building blocks” of visual perception. Autism Res 2016, 9: 866–878. © 2015 En ligne : http://dx.doi.org/10.1002/aur.1579 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=293
in Autism Research > 9-8 (August 2016) . - p.866-878[article] The developmental trajectory of contrast sensitivity in autism spectrum disorder [Texte imprimé et/ou numérique] / Jacalyn GUY, Auteur ; Laurent MOTTRON, Auteur ; Claude BERTHIAUME, Auteur ; Armando BERTONE, Auteur . - p.866-878.
Langues : Anglais (eng)
in Autism Research > 9-8 (August 2016) . - p.866-878
Mots-clés : autism spectrum disorder low-level perception development spatial frequency contrast sensitivity Index. décimale : PER Périodiques Résumé : Autism Spectrum Disorder (ASD) is characterized by a detail-driven visual processing strategy, evidence for which has been based largely on cross-sectional studies in small participant groups of limited age ranges. It is therefore unknown when sensitivity to detailed information emerges and develops in ASD. Contrast sensitivity to sinusoidal gratings of different spatial frequencies (0.5, 1, 2, 4, and 8 cycles per degree (cpd)) was measured for 34 participants with ASD and 55 typically developing participants (aged 6–16 years). Cross-sectional, developmental trajectories were constructed to examine within and between group differences across the range of spatial frequencies tested. Developmental trajectories indicated that sensitivity across low (i.e., 0.5 and 1 cpd) and mid (2 and 4 cpd) spatial frequencies varied by chronological age within each group, with mid frequencies developing at a more significant rate than low frequencies. There was no overall difference between groups in terms of the relationship of sensitivity and age across spatial frequencies, yet the ASD group had an overall lower level of sensitivity. Closer examination revealed that the youngest participants with ASD had a reduced sensitivity for mid frequencies. Moreover, the ASD group showed a statistically significant developmental relationship at 8 cpd, which suggests that a trend for increased sensitivity to early detailed information may manifest beyond the ages tested. These findings demonstrate a differential development of contrast sensitivity for spatial frequencies in ASD and underscore the need to better identify what drives such differences in the “building blocks” of visual perception. Autism Res 2016, 9: 866–878. © 2015 En ligne : http://dx.doi.org/10.1002/aur.1579 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=293 Neurophysiological hyperresponsivity to sensory input in autism spectrum disorders / Y. TAKARAE in Journal of Neurodevelopmental Disorders, 8-1 (December 2016)
[article]
Titre : Neurophysiological hyperresponsivity to sensory input in autism spectrum disorders Type de document : Texte imprimé et/ou numérique Auteurs : Y. TAKARAE, Auteur ; S. R. SABLICH, Auteur ; S. P. WHITE, Auteur ; J. A. SWEENEY, Auteur Article en page(s) : p.29 Langues : Anglais (eng) Mots-clés : Autism Contrast sensitivity Heterogeneity Individual differences Sensory hypersensitivity Index. décimale : PER Périodiques Résumé : BACKGROUND: Atypical sensory processing is a common clinical observation in autism spectrum disorder (ASD). Neural hyperexcitability has been suggested as the cause for sensory hypersensitivity, a frequently reported clinical observation in ASD. We examined visual evoked responses to parametric increases in stimulus contrast in order to model neural responsivity of sensory systems in ASD. METHODS: Thirteen high-functioning individuals with ASD and 12 typically developing (TD) individuals completed a steady-state visual evoked potential study. Stimuli were vertical circular gratings oscillating at 3.76 Hz at varying contrasts (5, 10, 20,..., 90 % contrast, 10 levels). The average spectral power at the stimulus oscillation frequency was calculated for each contrast level. RESULTS: The magnitude of evoked sensory responses increased at a significantly greater rate and resulted in disproportionately elevated activation with higher contrasts in the ASD group. Approximately 45 % of ASD participants had rates of response increases greater than any TD participant. This alteration was highly associated with parental reports of these participants' sensory difficulties. CONCLUSIONS: Greater increases in visual responses over contrast manipulation suggest heightened excitability in the sensory cortex in ASD participants. Heightened neural excitability was observed in a substantial portion but not all of the ASD participants. This pattern suggests that individuals with higher excitability may constitute a neurobiologically distinct subgroup requiring individualized treatment interventions. En ligne : http://dx.doi.org/10.1186/s11689-016-9162-9 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=349
in Journal of Neurodevelopmental Disorders > 8-1 (December 2016) . - p.29[article] Neurophysiological hyperresponsivity to sensory input in autism spectrum disorders [Texte imprimé et/ou numérique] / Y. TAKARAE, Auteur ; S. R. SABLICH, Auteur ; S. P. WHITE, Auteur ; J. A. SWEENEY, Auteur . - p.29.
Langues : Anglais (eng)
in Journal of Neurodevelopmental Disorders > 8-1 (December 2016) . - p.29
Mots-clés : Autism Contrast sensitivity Heterogeneity Individual differences Sensory hypersensitivity Index. décimale : PER Périodiques Résumé : BACKGROUND: Atypical sensory processing is a common clinical observation in autism spectrum disorder (ASD). Neural hyperexcitability has been suggested as the cause for sensory hypersensitivity, a frequently reported clinical observation in ASD. We examined visual evoked responses to parametric increases in stimulus contrast in order to model neural responsivity of sensory systems in ASD. METHODS: Thirteen high-functioning individuals with ASD and 12 typically developing (TD) individuals completed a steady-state visual evoked potential study. Stimuli were vertical circular gratings oscillating at 3.76 Hz at varying contrasts (5, 10, 20,..., 90 % contrast, 10 levels). The average spectral power at the stimulus oscillation frequency was calculated for each contrast level. RESULTS: The magnitude of evoked sensory responses increased at a significantly greater rate and resulted in disproportionately elevated activation with higher contrasts in the ASD group. Approximately 45 % of ASD participants had rates of response increases greater than any TD participant. This alteration was highly associated with parental reports of these participants' sensory difficulties. CONCLUSIONS: Greater increases in visual responses over contrast manipulation suggest heightened excitability in the sensory cortex in ASD participants. Heightened neural excitability was observed in a substantial portion but not all of the ASD participants. This pattern suggests that individuals with higher excitability may constitute a neurobiologically distinct subgroup requiring individualized treatment interventions. En ligne : http://dx.doi.org/10.1186/s11689-016-9162-9 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=349