{"success":true,"database":"eegdash","data":{"_id":"6953f4249276ef1ee07a33ed","dataset_id":"ds005491","associated_paper_doi":"10.1038/s41467-017-02753-0","authors":["Haydn G. Herrema","Michael J. Kahana"],"bids_version":"1.7.0","contact_info":null,"contributing_labs":null,"data_processed":false,"dataset_doi":"doi:10.18112/openneuro.ds005491.v1.0.0","datatypes":["ieeg"],"demographics":{"subjects_count":19,"ages":[31,36,24,27,33,40,49,28,34,28,20,36,45,26,24,44,22,21,28],"age_min":20,"age_max":49,"age_mean":31.36842105263158,"species":null,"sex_distribution":{"f":10,"m":9},"handedness_distribution":{"r":17,"l":2}},"experimental_modalities":null,"external_links":{"paper_url":"https://www.nature.com/articles/s41467-017-02753-0.pdf"},"funding":["DARPA RAM: N66001-14-2-4032"],"ingestion_fingerprint":"109dc4c38bc246d7c21f1e5108a6bfb0b5279996eae538081d53770aec5c030b","license":"CC0","n_contributing_labs":null,"name":"Categorized Free Recall with Open-Loop Stimulation at Encoding","readme":"### Categorized Free Recall with Open-Loop Stimulation at Encoding\n#### Description\nThis dataset contains behavioral events and intracranial electrophysiological recordings from a categorized free recall task with open-loop stimulation at encoding.  The experiment consists of participants studying a list of words, presented visually one at a time, completing simple arithmetic problems that function as a distractor, and then freely recalling the words from the just-presented list in any order.  The data was collected at clinical sites across the country as part of a collaboration with the Computational Memory Lab at the University of Pennsylvania.\nThe word lists in this paradigm follow a specific semantic construction.  Each word comes from one of 25 semantic categories, and each list of 12 items contains 6 pairs of same-category words from 3 different categories.  This means that each list has 4 words from 3 semantic categories, and in each half of the list there will be 1 pair of words from each category.  For example, if a list contains words from categories A, B, and C, a possible list construction would be:\n**A1 - A2 - B1 - B2 - C1 - C2 - A3 - A4 - C3 - C4 - B3 - B4**\nThis study contains open-loop electrical stimulation of the brain during encoding.  There is no stimulation during the distractor or retrieval phases.  Stimulation is delivered to a single electrode at a time, with locations chosen in the hippocampus and entorhinal cortex.  Stimulation parameters are included in the behavioral events tsv files, denoting the anode/cathode labels, amplitude, pulse frequency, pulse width, and pulse count.\n20 of the 25 lists in a session are randomly assigned as stimulation lists.  On these lists, stimulation occurs on alternating two-word blocks, meaning 6 of the 12 words are presented with stimulation.  Stimulation starts 200 ms prior to the onset of the first word in the block and lasts for 4.6 seconds, ending 200-450 ms after the offset of the second word (depending on the inter-stimulus interval).  Half of the stimulation lists begin with a stimulation on pair and half begin with a stumulation off pair, but the order of these conditions is random.  A stimulation list that begins with a stimulation on pair would look as follows (with bold indicating stimulation):\n**1 - 2** | 3 - 4 | **5 - 6** | 7 - 8 | **9 - 10** | 11 - 12\n#### To Note\n* The iEEG recordings are labeled either \"monopolar\" or \"bipolar.\"  The monopolar recordings are referenced (typically a mastoid reference), but should always be re-referenced before analysis.  The bipolar recordings are referenced according to a paired scheme indicated by the accompanying bipolar channels tables.\n* Each subject has a unique montage of electrode locations.  MNI and Talairach coordinates are provided when available.\n* Recordings done with the Blackrock system are in units of 250 nV, while recordings done with the Medtronic system are estimated through testing to have units of 0.1 uV.  We have completed the scaling to provide values in V.\n#### Contact\nFor questions or inquiries, please contact sas-kahana-sysadmin@sas.upenn.edu.","recording_modality":["ieeg"],"senior_author":null,"sessions":["0","1","2"],"size_bytes":24203328931,"source":"openneuro","study_design":null,"study_domain":null,"tasks":["catFR2"],"timestamps":{"digested_at":"2026-05-31T16:19:01.028179+00:00","dataset_created_at":null,"dataset_modified_at":null},"total_files":51,"storage":{"backend":"s3","base":"s3://openneuro.org/ds005491","raw_key":"dataset_description.json","dep_keys":["CHANGES","README","participants.json","participants.tsv"]},"tagger_meta":{"model":"openai/gpt-4o","tagged_at":"2026-06-10T08:19:41Z","source":"eegdash-llm-tagger"},"tags":{"pathology":["Healthy"],"modality":["Visual"],"type":["Memory"],"confidence":{"pathology":0.8,"modality":0.9,"type":0.9},"reasoning":{"few_shot_analysis":"The few-shot examples provide guidance on assigning labels based on task paradigms and participant characteristics. For instance, tasks involving free recall or categorized recall, especially where visual stimuli (words) are presented, often fall under 'Memory' type. Additionally, if the dataset emphasizes encoding and retrieval processes, it aligns further with Memory. None of the few-shot examples indicate a similar pathology or specific cognitive disorder, suggesting a default assignment of 'Healthy' in the absence of a specified clinical population.","metadata_analysis":"The dataset description states 'participants studying a list of words, presented visually one at a time' which indicates a 'Visual' modality. The task is a 'categorized free recall task,' which is aligned with a Memory-based study, as it involves recalling presented information. There is no mention of a clinical population, indicating that participants are likely healthy.","paper_abstract_analysis":"No useful paper information.","evidence_alignment_check":"For Pathology, the metadata suggests 'Healthy' since no clinical group is specified. The few-shot examples confirm assigning 'Healthy' if details of a clinical cohort are missing. For Modality, metadata specifies 'visually presented' tasks, aligning with the few-shot's interpretation of visual stimuli, confirming 'Visual' modality. For Type, the focus on free recall tasks matches precisely with 'Memory' classification in the few-shot example involving similar tasks.","decision_summary":"For Pathology, the primary candidate is 'Healthy' due to a lack of specified clinical conditions, supported by the absence of any clinical population in metadata. For Modality, 'Visual' is most supported by the direct reference to visually presented stimuli. For Type, 'Memory' is the most appropriate given the task's emphasis on encoding and recall. Metadata supports these decisions strongly, aligning with both direct information and established patterns in the few-shot examples."}},"nemar_citation_count":0,"computed_title":"Categorized Free Recall with Open-Loop Stimulation at Encoding","nchans_counts":[{"val":64,"count":5},{"val":126,"count":5},{"val":88,"count":4},{"val":85,"count":3},{"val":93,"count":3},{"val":113,"count":2},{"val":116,"count":2},{"val":133,"count":2},{"val":155,"count":2},{"val":163,"count":2},{"val":104,"count":2},{"val":112,"count":1},{"val":110,"count":1},{"val":128,"count":1},{"val":16,"count":1},{"val":80,"count":1},{"val":96,"count":1},{"val":130,"count":1},{"val":92,"count":1},{"val":72,"count":1},{"val":78,"count":1},{"val":115,"count":1},{"val":146,"count":1},{"val":124,"count":1},{"val":127,"count":1},{"val":68,"count":1},{"val":14,"count":1},{"val":70,"count":1},{"val":119,"count":1},{"val":177,"count":1}],"sfreq_counts":[{"val":500.0,"count":39},{"val":1600.0,"count":6},{"val":999.0,"count":4},{"val":1000.0,"count":2}],"stats_computed_at":"2026-05-31T19:34:32.601244+00:00","total_duration_s":168067.0,"canonical_name":null,"name_confidence":0.62,"name_meta":{"suggested_at":"2026-04-14T10:18:35.343Z","model":"openai/gpt-5.2 + openai/gpt-5.4-mini + deterministic_fallback"},"name_source":"canonical","author_year":"Herrema2024_Categorized","bad_channels_info":null,"acknowledgements":"We thank our collaborators who have helped in the collection of this data: Hospital of the University of Pennsylvania, Thomas Jefferson University Hospital, Dartmouth-Hitchcock Medical Center, Mayo Clinic, Columbia University Hospital, Emory University Hospital, University of Washington Medical Center.","associated_paper_meta":{"channel":"search","confidence":"medium","author_overlap":1,"is_oa":true,"oa_status":"gold","source":"paper_resolver"}}}