Altered oscillation patterns and connectivity during picture naming in autism

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Cognitive Neuroscience

Background:

• Autism spectrum disorder (ASD) is associated with behavioral deficits in social cognition and language.
• Previous research indicates abnormalities in brain regions like the fusiform gyrus (FG) and altered high-frequency brain oscillations in ASD.
• Shared behavioral deficits between individuals with ASD and their first-degree relatives suggest underlying neurobiological similarities.

Purpose of the Study:

• To investigate differences in low- and high-frequency brain oscillatory power and connectivity in individuals with ASD and their first-degree relatives.
• To examine these differences during a picture-naming task, focusing on brain regions implicated in language and face processing, such as the fusiform gyrus (FG).

Main Methods:

• Magnetoencephalography (MEG) was used to record brain activity in 12 individuals with ASD, 16 first-degree relatives, and 35 healthy controls.
• Participants performed a picture-naming task to assess oscillatory power and functional connectivity in specific frequency bands (beta and gamma).

Main Results:

• Individuals with ASD showed reduced evoked high-gamma activity in the right superior temporal gyrus (STG) and reduced high-beta/low-gamma evoked power in the left inferior frontal gyrus (IFG).
• Reductions in phase-locked beta-band activity were observed in the occipital lobes (OCC) in the ASD group.
• First-degree relatives exhibited increased high-gamma power in the left STG and increased high-beta/low-gamma power in the left FG.
• Functional connectivity in the beta and gamma bands between IFG-FG and STG-OCC was higher in the ASD group compared to controls.

Conclusions:

• Findings suggest altered oscillatory power and connectivity in ASD, with some measures differing between individuals with ASD and their relatives.
• Increased connectivity in certain brain regions in the ASD group contradicts previous notions of universal connectivity reduction.
• The observed patterns in relatives may indicate compensatory mechanisms related to gamma and beta band activity.