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Stronger Neural Modulation by Visual Motion Intensity in Autism Spectrum Disorders.

Peiker I, Schneider TR, Milne E, Schöttle D, Vogeley K, Münchau A, Schunke O, Siegel M, Engel AK, David N - PLoS ONE (2015)

Bottom Line: A polynomial regression analysis revealed that gamma-band power increased significantly stronger with motion coherence in ASD compared to controls, suggesting excessive visual activation with increasing stimulus intensity originating from motion-responsive visual areas V3, V6 and hMT/V5.Enhanced neural responses with increasing stimulus intensity suggest an enhanced response gain in ASD.Thus, our data suggest that a disturbed excitatory-inhibitory balance underlies enhanced neural responses to coherent motion in ASD.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.

ABSTRACT
Theories of autism spectrum disorders (ASD) have focused on altered perceptual integration of sensory features as a possible core deficit. Yet, there is little understanding of the neuronal processing of elementary sensory features in ASD. For typically developed individuals, we previously established a direct link between frequency-specific neural activity and the intensity of a specific sensory feature: Gamma-band activity in the visual cortex increased approximately linearly with the strength of visual motion. Using magnetoencephalography (MEG), we investigated whether in individuals with ASD neural activity reflect the coherence, and thus intensity, of visual motion in a similar fashion. Thirteen adult participants with ASD and 14 control participants performed a motion direction discrimination task with increasing levels of motion coherence. A polynomial regression analysis revealed that gamma-band power increased significantly stronger with motion coherence in ASD compared to controls, suggesting excessive visual activation with increasing stimulus intensity originating from motion-responsive visual areas V3, V6 and hMT/V5. Enhanced neural responses with increasing stimulus intensity suggest an enhanced response gain in ASD. Response gain is controlled by excitatory-inhibitory interactions, which also drive high-frequency oscillations in the gamma-band. Thus, our data suggest that a disturbed excitatory-inhibitory balance underlies enhanced neural responses to coherent motion in ASD.

No MeSH data available.


Related in: MedlinePlus

Linear coefficients estimated with polynomial regression.(A) Time-frequency representation of the linear coefficients, averaged across posterior sensors (see schematic head in Fig 2) and within groups (left: ASD, right: Control). (B) Time-frequency representation of the statistical difference of linear coefficients compared between groups (ASD—Control). Colors represent numbers of sensors belonging to the significant cluster. Y-axes of the gray-shaded curves represent the integrated number of sensors (number of sensors [n] multiplied with the respective domain, time [s] or frequency [Hz]).
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pone.0132531.g003: Linear coefficients estimated with polynomial regression.(A) Time-frequency representation of the linear coefficients, averaged across posterior sensors (see schematic head in Fig 2) and within groups (left: ASD, right: Control). (B) Time-frequency representation of the statistical difference of linear coefficients compared between groups (ASD—Control). Colors represent numbers of sensors belonging to the significant cluster. Y-axes of the gray-shaded curves represent the integrated number of sensors (number of sensors [n] multiplied with the respective domain, time [s] or frequency [Hz]).

Mentions: After source reconstruction, data were averaged across frequencies (60–80 Hz) and time points (150–350 ms). As for all sensor-level analyses, baseline-level activity was first subtracted from activity of the stimulus interval and the difference was then divided by baseline-activity. Next, polynomial regression was applied to the response at each cortical voxel (see above). Finally, coefficients were averaged across participants. Statistical analysis was calculated at the sensor-level (Fig 3), from which our main conclusions were inferred. At the cortical source-level, we sought to only descriptively investigate the likely sources of the group effect, but not to statistically infer conclusions.


Stronger Neural Modulation by Visual Motion Intensity in Autism Spectrum Disorders.

Peiker I, Schneider TR, Milne E, Schöttle D, Vogeley K, Münchau A, Schunke O, Siegel M, Engel AK, David N - PLoS ONE (2015)

Linear coefficients estimated with polynomial regression.(A) Time-frequency representation of the linear coefficients, averaged across posterior sensors (see schematic head in Fig 2) and within groups (left: ASD, right: Control). (B) Time-frequency representation of the statistical difference of linear coefficients compared between groups (ASD—Control). Colors represent numbers of sensors belonging to the significant cluster. Y-axes of the gray-shaded curves represent the integrated number of sensors (number of sensors [n] multiplied with the respective domain, time [s] or frequency [Hz]).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492621&req=5

pone.0132531.g003: Linear coefficients estimated with polynomial regression.(A) Time-frequency representation of the linear coefficients, averaged across posterior sensors (see schematic head in Fig 2) and within groups (left: ASD, right: Control). (B) Time-frequency representation of the statistical difference of linear coefficients compared between groups (ASD—Control). Colors represent numbers of sensors belonging to the significant cluster. Y-axes of the gray-shaded curves represent the integrated number of sensors (number of sensors [n] multiplied with the respective domain, time [s] or frequency [Hz]).
Mentions: After source reconstruction, data were averaged across frequencies (60–80 Hz) and time points (150–350 ms). As for all sensor-level analyses, baseline-level activity was first subtracted from activity of the stimulus interval and the difference was then divided by baseline-activity. Next, polynomial regression was applied to the response at each cortical voxel (see above). Finally, coefficients were averaged across participants. Statistical analysis was calculated at the sensor-level (Fig 3), from which our main conclusions were inferred. At the cortical source-level, we sought to only descriptively investigate the likely sources of the group effect, but not to statistically infer conclusions.

Bottom Line: A polynomial regression analysis revealed that gamma-band power increased significantly stronger with motion coherence in ASD compared to controls, suggesting excessive visual activation with increasing stimulus intensity originating from motion-responsive visual areas V3, V6 and hMT/V5.Enhanced neural responses with increasing stimulus intensity suggest an enhanced response gain in ASD.Thus, our data suggest that a disturbed excitatory-inhibitory balance underlies enhanced neural responses to coherent motion in ASD.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.

ABSTRACT
Theories of autism spectrum disorders (ASD) have focused on altered perceptual integration of sensory features as a possible core deficit. Yet, there is little understanding of the neuronal processing of elementary sensory features in ASD. For typically developed individuals, we previously established a direct link between frequency-specific neural activity and the intensity of a specific sensory feature: Gamma-band activity in the visual cortex increased approximately linearly with the strength of visual motion. Using magnetoencephalography (MEG), we investigated whether in individuals with ASD neural activity reflect the coherence, and thus intensity, of visual motion in a similar fashion. Thirteen adult participants with ASD and 14 control participants performed a motion direction discrimination task with increasing levels of motion coherence. A polynomial regression analysis revealed that gamma-band power increased significantly stronger with motion coherence in ASD compared to controls, suggesting excessive visual activation with increasing stimulus intensity originating from motion-responsive visual areas V3, V6 and hMT/V5. Enhanced neural responses with increasing stimulus intensity suggest an enhanced response gain in ASD. Response gain is controlled by excitatory-inhibitory interactions, which also drive high-frequency oscillations in the gamma-band. Thus, our data suggest that a disturbed excitatory-inhibitory balance underlies enhanced neural responses to coherent motion in ASD.

No MeSH data available.


Related in: MedlinePlus