{
  "abstract": "BACKGROUND: Brain function is the dynamic output of coordinated excitatory and inhibitory (E-I) activity. E-I alterations, arising from differences in excitatory glutamate and inhibitory GABA pathways, are implicated in the development and heterogeneity of autism, and are consequently targets for pharmacological support options. Existing tools, such as Magnetic Resonance Spectroscopy, are limited in capturing the dynamic nature of E-I regulation. The aperiodic 1/f exponent of the EEG power spectrum has shown sensitivity to E-I perturbations in animals and neurotypical humans, but its applicability to neurodiverse populations remains underexplored. METHODS: Therefore, as proof-of-concept, this study tested the hypotheses that (i) the aperiodic 1/f exponent of resting-state EEG changes following a pharmacological E-I challenge with arbaclofen (STX209), a GABAB receptor agonist; and (ii) dynamic responsivity to GABAergic challenge is different in autism. Participants were 40 adults, 15 autistic. EEG was recorded at rest after randomised, double-blind administration of a placebo, 15 mg of arbaclofen, and 30 mg of arbaclofen. Aperiodic 1/f exponents were extracted. RESULTS: As predicted, in both groups the aperiodic 1/f exponent significantly increased following a high (30 mg) dose of arbaclofen, replicating the effect observed in animals. Furthermore, a lower (15 mg) dose showed a different response pattern across groups, with aperiodic exponents tending to increase in autistic individuals but decrease in non-autistic individuals, suggesting differences in GABAergic responsivity. CONCLUSIONS: These findings support the aperiodic 1/f exponent as a metric for dynamic E-I regulation and provide preliminary evidence of distinct homeostatic E-I dynamics in autism.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK",
    "Sackler Institute for Translational Neurodevelopment, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK",
    "School of Human Sciences, University of Greenwich, London, UK",
    "School of Computer Science and Informatics, Cardiff University, Cardiff, UK",
    "Institute for Nuclear Sciences Applied to Health (ICNAS), Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, Portugal",
    "Department of Psychology, The University of Hong Kong, Hong Kong",
    "Mental Health and Intellectual Disability, Stewarts Care, Dublin, Ireland",
    "Saint John of God Community Services, Liffey Services, Intellectual Disability Psychiatry, Celbridge, Ireland",
    "Roche Pharma Research and Early Development, Neuroscience and Rare Diseases, Roche Innovation Center Basel, Basel, Switzerland",
    "South London and Maudsley, NHS Foundation Trust"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 15,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Claire L. Ellis",
      "orcid": "0000-0002-1064-2395"
    },
    {
      "affs": [
        0,
        2
      ],
      "name": "Jumana Ahmad",
      "orcid": "0000-0001-5271-0731"
    },
    {
      "affs": [
        3
      ],
      "name": "Alexia Zoumpoulaki",
      "orcid": "0000-0002-0810-0319"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Mihail Dimitrov",
      "orcid": "0000-0002-0760-5905"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Hester Velthuis",
      "orcid": "0000-0001-9219-3687"
    },
    {
      "affs": [
        0,
        4,
        1
      ],
      "name": "Andreia Carvalho Pereira",
      "orcid": "0000-0003-4418-2638"
    },
    {
      "affs": [
        0,
        5,
        1
      ],
      "name": "Nichol M. L. Wong",
      "orcid": "0000-0003-0050-7736"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Francesca M. Ponteduro",
      "orcid": "0000-0002-1244-3090"
    },
    {
      "affs": [
        0,
        6,
        1,
        7
      ],
      "name": "Łukasz Kowalewski",
      "orcid": "0009-0008-4005-2610"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Alison Leonard",
      "orcid": "0000-0002-8832-8275"
    },
    {
      "affs": [
        8
      ],
      "name": "Pilar Garces"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Qiyun Huang",
      "orcid": "0000-0003-0570-4771"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Eileen Daly",
      "orcid": "0000-0003-3625-3467"
    },
    {
      "affs": [
        0,
        1,
        9
      ],
      "name": "Declan G. Murphy"
    },
    {
      "affs": [
        0,
        1,
        9
      ],
      "name": "Grainne Mary McAlonan",
      "orcid": "0000-0002-4466-2343"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/47zxwff0zsrzn.bib",
  "cited_by": 8,
  "doi": "10.1177/02698811261449378",
  "fulltext_url": null,
  "id": "47zxwff0zsrzn",
  "issns": [
    "0269-8811",
    "1461-7285"
  ],
  "landing_url": "https://doi.org/10.1177/02698811261449378",
  "language": "en",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
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      "2805|Autism Spectrum Disorder Research"
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  "openalex": "W7161241788",
  "pdf_url": null,
  "pmcid": null,
  "pmid": "42138309",
  "published": "2026-05-15",
  "publisher": "SAGE Publishing",
  "ris": "https://research.draconitic.com/paper/47zxwff0zsrzn.ris",
  "sources": [
    {
      "first_seen": "2026-11-04T13:21:11Z",
      "native_id": "W7161241788",
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      "url": "https://doi.org/10.1177/02698811261449378"
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  "subjects": [
    {
      "field": "biology",
      "origin": "openalex:2805|Autism Spectrum Disorder Research",
      "subfield": "neuroscience"
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  ],
  "title": "Dynamic excitatory-inhibitory differences in autistic and non-autistic adults: Evidence from a pharmacological challenge with arbaclofen",
  "title_text": "Dynamic excitatory-inhibitory differences in autistic and non-autistic adults: Evidence from a pharmacological challenge with arbaclofen",
  "type": "peer-reviewed",
  "updated_at": "2026-11-09T13:21:12Z",
  "url": "https://research.draconitic.com/paper/47zxwff0zsrzn",
  "venue": "Journal of Psychopharmacology",
  "versions": []
}