Stable quantitative EEG difference in post-LSD visual disorder by split-half analysis: evidence for disinhibition.
H D Abraham, F H Duffy
Psychiatry Research October 7, 1996 DOI: 10.1016/0925-4927(96)02833-8 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Case-control study Peer reviewed |
|---|---|
| Sample size | 132 |
| Population | 44 subjects with LSD-induced HPPD and 88 matched controls |
| Measures | quantitative EEG (qEEG), visual evoked response (VER), auditory evoked response (AER), T-statistic significance probability mapping (T-SPM) |
| Topics | LSD |
| Key findings | HPPD subjects showed faster alpha frequency and shorter visual evoked response latency but prolonged auditory evoked response latency compared with controls, consistent with LSD-induced cortical disinhibition and differing visual versus auditory effects. EEG-based discriminant analysis classified groups with 87% prospective success by jackknifing and 88% in a split-half analysis. |
Abstract
Hallucinogen persisting perceptual disorder (HPPD) may follow the ingestion of LSD or other hallucinogens in a subset of users. It is characterized by chronic, intermittent or constant visual hallucinations of many sorts persisting beyond the period of acute drug effects. We studied 44 LSD-induced HPPD subjects and 88 matched controls to search for spectral and evoked potential differences using quantitative EEG (qEEG). HPPD subjects demonstrated faster alpha frequency and shorter VER (visual evoked response) latency, consistent with prior animal and human data on response to acute LSD administration which suggest LSD-induced cortical disinhibition. AER (auditory evoked response) latency was prolonged consistent with a differential LSD effect upon visual and auditory systems. The exploratory T-statistic significance probability mapping (T-SPM) technique demonstrated HPPD-control differences mostly involving temporal and left parietal scalp regions, confirmed by a split-half analysis. Significant variables were all derived from the long latency flash VER and click AER. None were derived from spectral analyzed EEG data. Canonical correlation between SPM-derived measures and variables reflecting disease severity was highly significant. A between-group stepwise discriminant analysis based upon a full set of qEEG measures demonstrated 87% prospective classification success by jackknifing and 88% success in a separate split-half analysis.
Comparable studies
Other observational and cohort studies on LSD, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Increased Global Functional Connectivity Correlates with LSD-Induced Ego Dissolution. Human participants | 2016 | Observational cohort | |
| Increased spontaneous MEG signal diversity for psychoactive doses of ketamine, LSD and psilocybin Humans | 2017 | Observational study | |
| Classic psychedelic use is associated with reduced psychological distress and suicidality in the United States adult population. USA adult respondents from the National Survey on Drug Use and Health (2008-2012) | 2015 | Observational cohort | n = 190,000 |
| Psychedelics not linked to mental health problems or suicidal behavior: A population study Randomly selected United States adults | 2015 | Observational cohort | n = 135,095 |
| Whole-Brain Multimodal Neuroimaging Model Using Serotonin Receptor Maps Explains Non-linear Functional Effects of LSD. Healthy human participants | 2018 | Observational study with computational modeling |
Citations in the library
Cited by 20
- Acute, subacute and long-term subjective effects of psilocybin in healthy humans: a pooled analysis of experimental studies Journal of Psychopharmacology September 20, 2010
- Hallucinogen Persisting Perception Disorder: Etiology, Clinical Features, and Therapeutic Perspectives Brain Sciences March 16, 2018
- Serotonergic Psychedelics Temporarily Modify Information Transfer in Humans The International Journal of Neuropsychopharmacology March 29, 2015
- Flashback phenomena after administration of LSD and psilocybin in controlled studies with healthy participants Psychopharmacology January 25, 2022
- EEG Gamma Coherence and Other Correlates of Subjective Reports During Ayahuasca Experiences Journal of Psychoactive Drugs June 1, 2005
and 15 more in the library
Cites 8
- Evidence for 5-HT2 involvement in the mechanism of action of hallucinogenic agents. Life Sciences December 17, 1984
- Lysergic Acid Diethylamide: Sensitive Neuronal Units in the Midbrain Raphe Science August 16, 1968
- Visual Phenomenology of the LSD Flashback Archives of General Psychiatry August 1, 1983
- Flashbacks: Recurrent Intrusive Images After the Use of LSD American Journal of Psychiatry October 1, 1969
- LSD has high efficacy relative to serotonin in enhancing the cationic current Ih: Intracellular studies in rat facial motoneurons Synapse February 1, 1993
and 3 more in the library