David A Edmondson1,2,3, Pingyu Xia1, Rebecca McNally Keehn4, Ulrike Dydak1,2, Brandon Keehn5,6. 1. School of Health Sciences, Purdue University, West Lafayette, Indiana. 2. Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana. 3. Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio. 4. Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana. 5. Department of Speech, Language, and Hearing Sciences, Purdue University, West Lafayette, Indiana. 6. Department of Psychological Sciences, Purdue University, West Lafayette, Indiana.
Abstract
Although diagnosed on the basis of deficits in social communication and interaction, autism spectrum disorder (ASD) is also characterized by superior performance on a variety of visuospatial tasks, including visual search. In neurotypical individuals, region-specific concentrations of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) are associated with individual differences in attention and perception. While it has been hypothesized that ASD may be associated with an excitatory-inhibitory imbalance, it remains unclear how this may contribute to accelerated visual search performance in individuals with ASD. To investigate this, 21 children with ASD and 20 typically developing children participated in a visual search task and a magnetic resonance spectroscopy study to detect neurochemical concentrations, including GABA. Region-specific neurochemicals were examined in the right frontal eye fields, right temporal-parietal junction (rTPJ), and bilateral visual cortex (VIS). GABA concentrations did not differ between groups; however, in children with ASD, greater GABA concentration in the VIS was related to more efficient search. Additionally, lower VIS GABA levels were also associated with increased social impairment. Finally, we found reduced N-acetyl aspartate, total creatine, glutamate and glutamine (Glx), GABA/Glx in the rTPJ, suggestive of neuronal dysfunction in a critical network hub. Our results show that GABA concentrations in the VIS are related to efficient search in ASD, thus providing further evidence of enhanced discrimination in ASD. Autism Res 2020, 13: 550-562.
Although diagnosed on the basis of deficits in social communication and interaction, autism spectrum disorder (ASD) is also characterized by superior performance on a variety of visuospatial tasks, including visual search. In neurotypical individuals, region-specific concentrations of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) are associated with individual differences in attention and perception. While it has been hypothesized that ASD may be associated with an excitatory-inhibitory imbalance, it remains unclear how this may contribute to accelerated visual search performance in individuals with ASD. To investigate this, 21 children with ASD and 20 typically developing children participated in a visual search task and a magnetic resonance spectroscopy study to detect neurochemical concentrations, including GABA. Region-specific neurochemicals were examined in the right frontal eye fields, right temporal-parietal junction (rTPJ), and bilateral visual cortex (VIS). GABA concentrations did not differ between groups; however, in children with ASD, greater GABA concentration in the VIS was related to more efficient search. Additionally, lower VIS GABA levels were also associated with increased social impairment. Finally, we found reduced N-acetyl aspartate, total creatine, glutamate and glutamine (Glx), GABA/Glx in the rTPJ, suggestive of neuronal dysfunction in a critical network hub. Our results show that GABA concentrations in the VIS are related to efficient search in ASD, thus providing further evidence of enhanced discrimination in ASD. Autism Res 2020, 13: 550-562.
Authors: Nicolaas A J Puts; Ericka L Wodka; Ashley D Harris; Deana Crocetti; Mark Tommerdahl; Stewart H Mostofsky; Richard A E Edden Journal: Autism Res Date: 2016-09-09 Impact factor: 5.216
Authors: Emily T Wood; Kaitlin K Cummings; Jiwon Jung; Genevieve Patterson; Nana Okada; Jia Guo; Joseph O'Neill; Mirella Dapretto; Susan Y Bookheimer; Shulamite A Green Journal: Transl Psychiatry Date: 2021-01-12 Impact factor: 6.222
Authors: Rebecca B Hughes; Jayde Whittingham-Dowd; Steven J Clapcote; Susan J Broughton; Neil Dawson Journal: Autism Res Date: 2022-02-10 Impact factor: 4.633