Visual processing in Autism-spectrum disorders

Visual processing in Autism-spectrum disorders - Visual processing in ASD

Status

Active, not recruiting

Phases

Unknown

Study type

Observational

Source

NL-OMON

Registry ID

NL-OMON38101

Enrollment

Registered

2010-10-29

Start date

2011-01-28

Completion date

Unknown

Last updated

2024-05-06

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Autism Autism-spectrum disorders

Interventions

None listed

Eligibility

Age

18 Years to 99 Years

Inclusion criteria

Inclusion criteria: 1. Positive diagnosis of one of the autism-spectrum disorders other than PDD-NOS (pervasive developmental disorder, not otherwise specified) - i.e. Autism or Asperger syndrome, based on the DSM-IV and in addition standardized diagnostic instruments were administered: the Autism Diagnostic Interview (ADI-R, Lord, Rutter, & Le Couteur, 1994) and the Autism Diagnostic Observation Schedule (ADOS, Lord et al., 1989). - for patient group only. 2. IQ greater than 70 (in the average range or above). 3. Age and sex match to patient group - for the healthy-volunteer group only. 4. Normal or corrected-to-normal vision. 5. Good health. 6. Age over 18.

Exclusion criteria

Exclusion criteria: 1. Diagnosis of PDD-NOS 2. Irremovable ferrous objects in or around the body (e.g. pacemaker, stents, splinters) 3. History of closed head injury 4. History of epilepsy 5. Claustrophobia 6. Pregnancy

Design outcomes

Primary

Measure	Time frame
We are primarily interested in estimates of cortical inhibition and the perceptual correlates of this cortical inhibition. Cortical inhibition will be estimated from the difference in BOLD signal activation (measured with fMRI), difference in amplitude of C1 visual evoked potential (measured with EEG) and difference in amplitude of gamma-power (measured with EEG) in response to homogeneous and inhomogeneous displays. Therefore, fMRI and EEG will be recorded while the subjects passively observe homogeneous and inhomogeneous displays appear on the screen. Perceptual correlates of cortical inhibition will be measured as the difference in inverse efficacy between conditions in which the context (surround) interfered with perception and conditions in which it does not.	—

Measure

Time frame

We are primarily interested in estimates of cortical inhibition and the perceptual correlates of this cortical inhibition. Cortical inhibition will be estimated from the difference in BOLD signal activation (measured with fMRI), difference in amplitude of C1 visual evoked potential (measured with EEG) and difference in amplitude of gamma-power (measured with EEG) in response to homogeneous and inhomogeneous displays. Therefore, fMRI and EEG will be recorded while the subjects passively observe homogeneous and inhomogeneous displays appear on the screen. Perceptual correlates of cortical inhibition will be measured as the difference in inverse efficacy between conditions in which the context (surround) interfered with perception and conditions in which it does not.

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Countries

Netherlands

Outcome results