{"success":true,"database":"eegdash","data":{"_id":"6953f4239276ef1ee07a32f2","dataset_id":"ds003800","associated_paper_doi":null,"authors":["Mojtaba Lahijanian","Mohammad Javad Sedghizadeh","Hamid Aghajan","Zahra Vahabi"],"bids_version":"1.0.0","contact_info":["Mojtaba Lahijanian"],"contributing_labs":null,"data_processed":false,"dataset_doi":"10.18112/openneuro.ds003800.v1.0.0","datatypes":["eeg"],"demographics":{"subjects_count":13,"ages":[65,70,75,82,75,69,89,70,57,81,88,63,60],"age_min":57,"age_max":89,"age_mean":72.61538461538461,"species":null,"sex_distribution":{"m":8,"f":5},"handedness_distribution":null},"experimental_modalities":null,"external_links":{"source_url":"https://openneuro.org/datasets/ds003800","osf_url":null,"github_url":null,"paper_url":null},"funding":["This work was partially funded by the Cognitive Sciences & Technologies Council of Iran and by the grant G970736 from Sharif University of Technology, which covered the cost of data collection. The funders had no role in the study conceptualization and design, data collection and analysis, decision to publish, or preparation of the manuscript. "],"ingestion_fingerprint":"f4d5c707f32b095949b002893613a956fe877f84ea2e7ebe11e2e12bb8033449","license":"CC0","n_contributing_labs":null,"name":"Auditory Gamma Entrainment","readme":"> Introduction\nThis experiment was designed to entrain the brain oscillations through synthetic auditory stimulation conducted on a group of elderly suffering from dementia. Recently, gamma entrainment has been proposed and shown effective in improving several symptoms of Alzheimer's Diseases (AD). The aim of this study is to investigate the effect of entrainment on brain oscillations using EEG signal recording during the auditory brain stimulation.\nThis study was approved by the Review Board of Tehran University of Medical Sciences (Approval ID: IR.TUMS.MEDICINE.REC.1398.524) and all participants provided informed consent before participating and were free to withdraw at any time.\n> Rest data\nBefore the main task, a one-minute data was recorded with open eyes for measuring raw resting-state potentials. The rest data for participants number 6 and 13 are missing.\n> Auditory stimulation\nTwo speakers were placed in front of the participant 50cm apart from each other and directly pointed at the participant's ears at a distance of 50cm. The sound intensity was around -40dB within a fixed range for all participants. Before starting the task, the participant was asked if the volume was loud enough and the sound volume was set at a comfortable level for each participant. The auditory stimulus was a 5kHz carrier tone amplitude modulated with a 40Hz rectangular wave (40Hz On and Off cycles). Since a 40Hz audio signal cannot be easily heard, the 5KHz carrier frequency was used to render the 40Hz pulse train audible. In order to minimize the effect of the carrier sound, the duty cycle of the modulating 40Hz waveform was set to 4% (1ms of the 25ms cycle was On). The auditory stimulant was generated in MATLAB and played as a .wav file. This file consisted of six trials of 40sec stimulus interleaved by five trials of 20sec rest (silence). The entire session resulted in 340sec (6*40+5*20) of recorded EEG signal.\n> EEG recording and preprocessing\nAll EEG data were recorded using 19 monopolar channels in the standard 10/20 system referenced to the earlobes, sampled at 250Hz, and the impedance of the electrodes was kept under 20kOhm.\nData from all the participants were preprocessed identically following Makoto's preprocessing pipeline: Highpass filtering above 1Hz; removal of the line noise; rejecting potential bad channels; interpolating rejected channels; re-referencing data to the average; Artifact Subspace Reconstruction (ASR); re-referencing data to the average again; estimating the brain source activity using independent component analysis (ICA); dipole fitting; rejecting bad dipoles (sources) for further cleaning the data. These preprocessing steps were performed using EEGLab MATLAB toolbox.\n> Instructions\nDuring the experiment, participants were seated comfortably with open eyes in a quiet room. They were instructed to relax their body to avoid muscle artifacts and move their head as little as possible.","recording_modality":["eeg"],"senior_author":"Zahra Vahabi","sessions":[],"size_bytes":198443567,"source":"openneuro","study_design":null,"study_domain":null,"tasks":["AuditoryGammaEntrainment","Rest"],"timestamps":{"digested_at":"2026-04-22T12:25:42.600651+00:00","dataset_created_at":"2021-09-12T18:22:56.180Z","dataset_modified_at":"2021-09-27T21:10:33.000Z"},"total_files":24,"storage":{"backend":"s3","base":"s3://openneuro.org/ds003800","raw_key":"dataset_description.json","dep_keys":["CHANGES","README","participants.json","participants.tsv"]},"tagger_meta":{"config_hash":"4a051be509a0e3d0","metadata_hash":"b2eb756b6475b640","model":"openai/gpt-5.2","tagged_at":"2026-01-20T10:20:31.036619+00:00"},"tags":{"pathology":["Dementia"],"modality":["Auditory"],"type":["Clinical/Intervention"],"confidence":{"pathology":0.85,"modality":0.9,"type":0.8},"reasoning":{"few_shot_analysis":"Most similar few-shot example by population is the dementia resting-state dataset (\"A dataset of EEG recordings from: Alzheimer's disease, Frontotemporal dementia and Healthy subjects\"), which maps an explicitly dementia/AD-recruited cohort to Pathology=Dementia and Type=Clinical/Intervention when the dataset purpose is clinical characterization. For intervention-style clinical EEG, the Parkinson's \"Cross-modal Oddball Task\" example shows the convention that when a clinical group is recruited and the study goal is to relate EEG markers to the disorder (or manipulate brain function), Type is labeled Clinical/Intervention rather than a basic cognitive construct. This dataset similarly recruits dementia/AD patients and applies stimulation (entrainment), so the same convention supports Type=Clinical/Intervention. Modality conventions from few-shot examples map sound-based paradigms to Modality=Auditory (e.g., the auditory brainstem response dataset; and auditory oddball TBI dataset), guiding Modality=Auditory here due to explicit auditory stimulation.","metadata_analysis":"Key quoted facts from the README:\n1) Population/condition: \"synthetic auditory stimulation conducted on a group of elderly suffering from dementia\" and \"improving several symptoms of Alzheimer's Diseases (AD)\".\n2) Study aim (intervention/entrainment): \"designed to entrain the brain oscillations\" and \"investigate the effect of entrainment on brain oscillations using EEG signal recording during the auditory brain stimulation\".\n3) Stimulus modality: \"Auditory stimulation\" and \"The auditory stimulus was a 5kHz carrier tone amplitude modulated with a 40Hz rectangular wave\".\n4) Resting context exists but is secondary: \"Before the main task, a one-minute data was recorded with open eyes for measuring raw resting-state potentials.\"","paper_abstract_analysis":"No useful paper information.","evidence_alignment_check":"Pathology:\n- Metadata says: \"elderly suffering from dementia\" and references \"Alzheimer's Diseases (AD)\".\n- Few-shot pattern suggests: explicit AD/dementia recruitment maps to Pathology=Dementia (see dementia few-shot example).\n- Alignment: ALIGN.\n\nModality:\n- Metadata says: \"Auditory stimulation\" with a \"5kHz carrier tone amplitude modulated with a 40Hz\" waveform played as \".wav\".\n- Few-shot pattern suggests: sound/click/speech/music paradigms map to Modality=Auditory.\n- Alignment: ALIGN.\n\nType:\n- Metadata says: \"designed to entrain the brain oscillations\" and aims to \"investigate the effect of entrainment\" in dementia/AD.\n- Few-shot pattern suggests: when a clinical cohort is recruited and the goal is disorder-related mechanistic/biomarker or intervention-like manipulation, label Type=Clinical/Intervention (as in the Parkinson's clinical example; also dementia dataset labeled Clinical/Intervention).\n- Alignment: ALIGN (intervention/neuromodulation-like entrainment in a dementia cohort).","decision_summary":"Top-2 candidate labels with head-to-head selection:\n\nPathology:\n1) Dementia (SELECTED) — Evidence: \"elderly suffering from dementia\"; \"Alzheimer's Diseases (AD)\"; clinical target is dementia/AD symptoms.\n2) Healthy — Only plausible if this were a normative entrainment study, but metadata explicitly states dementia/AD recruitment.\nAlignment status: Aligns with few-shot dementia convention. Confidence supported by 2+ explicit metadata quotes.\n\nModality:\n1) Auditory (SELECTED) — Evidence: section titled \"Auditory stimulation\"; \"auditory stimulus was a 5kHz carrier tone amplitude modulated with a 40Hz\"; played as \".wav file\" through \"Two speakers\".\n2) Resting State — A 1-minute eyes-open baseline exists (\"one-minute... recorded with open eyes\"), but the dominant/primary paradigm is auditory stimulation/entrainment.\nAlignment status: Aligns with few-shot auditory datasets. Confidence supported by 3+ explicit metadata quotes.\n\nType:\n1) Clinical/Intervention (SELECTED) — Evidence: clinical cohort (dementia/AD) plus manipulation: \"designed to entrain the brain oscillations\"; \"investigate the effect of entrainment... during the auditory brain stimulation\"; framed as improving AD symptoms.\n2) Perception — Could be argued because an auditory stimulus is presented, but the stated aim is not auditory perception/discrimination; it is entrainment/clinical effect measurement.\nAlignment status: Aligns with few-shot convention that clinical manipulation/biomarker-focused studies in patient cohorts map to Clinical/Intervention. Confidence supported by 2+ explicit metadata quotes about entrainment aim plus clinical framing."}},"nemar_citation_count":4,"computed_title":"Auditory Gamma Entrainment","nchans_counts":[{"val":19,"count":24}],"sfreq_counts":[{"val":250.0,"count":24}],"stats_computed_at":"2026-04-21T23:17:03.700333+00:00","total_duration_s":5080.0,"author_year":"Lahijanian2021_Auditory","canonical_name":null}}