{
  "abstract": "Non-invasive proxies of cortical excitation--inhibition (E:I) balance, are increasingly used to understand human neural dynamics; especially so the aperiodic (1/f) electroencephalographic (EEG) exponent. Ketamine, an NMDA-receptor antagonist, is thought to shift this balance toward excitation. Propofol, a GABAA-receptor agonist, should behave oppositely. Here we show that these pharmacological manipulations at low doses tilt the noninvasive read-out of E:I balance as predicted, and we demonstrate this effect to be robust against potential mediation by the ketamine-related systemic cardiovascular response. In a single-blind, placebo-controlled crossover study, 25 healthy adults received low, subanesthetic doses of ketamine, propofol, or placebo by target-controlled infusion during resting-state EEG. We further analyzed electrocardiogram (ECG) and dissociating ratings. Ketamine flattened the aperiodic exponent (i.e., a shift toward excitation) and raised heart rate and blood pressure; propofol exerted its effects in the opposite direction, while both agents reduced alpha oscillatory power. Critically, the cardiovascular response did not mediate the cortical E:I shift. Controlling for heart rate left the ketamine effect not only intact but numerically stronger, suggesting that E:I balance findings might even be underestimated when ignoring the systemic physiological response.",
  "abstract_shown": true,
  "affiliations": [
    "University of Luebeck"
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 10,
  "authors": [
    {
      "name": "J. Kunze"
    },
    {
      "name": "J. P. Student"
    },
    {
      "name": "S. Tune"
    },
    {
      "name": "H. Oster"
    },
    {
      "name": "S. Schmidt"
    },
    {
      "name": "H. Ihmsen"
    },
    {
      "name": "A. Tzabazis"
    },
    {
      "name": "B. Lorenz"
    },
    {
      "name": "C. Nau"
    },
    {
      "affs": [
        0
      ],
      "name": "J. Obleser"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/f3445dfqy2pkh.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.09.17.752361",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.09.17.752361v1.full",
  "id": "f3445dfqy2pkh",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.09.17.752361v1",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "biorxiv",
      "neuroscience"
    ],
    [
      "openalex",
      "2805|Neural dynamics and brain function"
    ]
  ],
  "openalex": "W7213983094",
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.09.17.752361v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-17",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/f3445dfqy2pkh.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:23:38Z",
      "native_id": "10.64898/2026.09.17.752361",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.09.17.752361v1"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "biorxiv:neuroscience",
      "subfield": "neuroscience"
    }
  ],
  "title": "Low-dose ketamine tilts the cortical excitation--inhibition balance irrespective of systemic physiological response",
  "title_text": "Low-dose ketamine tilts the cortical excitation--inhibition balance irrespective of systemic physiological response",
  "type": "preprint",
  "updated_at": "2026-10-30T12:23:38Z",
  "url": "https://research.draconitic.com/paper/f3445dfqy2pkh",
  "venue": "bioRxiv",
  "versions": []
}