Brief report: Anomalous neural deactivations and functional connectivity during receptive language in autism spectrum disorder: a functional MRI study.

Ariel Karten,Joy Hirsch

doi:10.1007/s10803-014-2344-y

Abstract

Neural mechanisms that underlie language disability in autism spectrum disorder (ASD) have been associated with reduced excitatory processes observed as positive blood oxygen level dependent (BOLD) responses. However, negative BOLD responses (NBR) associated with language and inhibitory processes have been less studied in ASD. In this study, functional magnetic resonance imaging showed that the NBR in ASD participants was reduced during passive listening to spoken narratives compared to control participants. Further, functional connectivity between the superior temporal gyrus and regions that exhibited a NBR during receptive language in control participants was increased in ASD participants. These findings extend models for receptive language disability in ASD to include anomalous neural deactivations and connectivity consistent with reduced or poorly modulated inhibitory processes.

Highlights

Autism spectrum disorder (ASD) is a prevalent neurodevelopmental disorder characterized by a spectrum of language and communication deficits without known mechanisms
Negative blood oxygen level dependent (BOLD) responses (NBR) associated with language and inhibitory processes have been less studied in autism spectrum disorder (ASD)
Functional imaging studies of auditory receptive language based on the positive blood oxygen level dependent (BOLD) response (PBR) have shown that the canonical language areas, such as Wernicke’s and Broca’s areas, are less activated in participants with ASD relative to typical controls (Gervais et al 2004; Lai et al 2011, 2012)

Summary

Introduction

Autism spectrum disorder (ASD) is a prevalent neurodevelopmental disorder characterized by a spectrum of language and communication deficits without known mechanisms. The PBR is interpreted as an engagement or excitation of a neural substrate (Logothetis et al 2001), whereas the NBR is thought to reflect alternative signal processes that have been associated with inhibitory or suppressive mechanisms (Smith et al 2004; Amedi et al 2005; Shmuel et al 2002, 2006; Wade 2002). The NBR presents a unique opportunity to investigate both regional responses and global neural networks involved in putative inhibitory processes associated with receptive language functions in ASD. We test the hypothesis that receptive language-related function in ASD is associated with reduced NBRs and altered functional connectivity consistent with anomalous inhibitory processes

Materials and Methods

Results

Discussion