{"success":true,"database":"eegdash","data":{"_id":"6953f4249276ef1ee07a3319","dataset_id":"ds004117","associated_paper_doi":null,"authors":["Julie Onton (data)","Scott Makeig (data and curation)","Arnaud Delorme (data and curation)","Dung Truong (curation)","Kay Robbins (curation)"],"bids_version":"1.7.0","contact_info":["Dung Truong","Kay Robbins"],"contributing_labs":null,"data_processed":false,"dataset_doi":"doi:10.18112/openneuro.ds004117.v1.0.1","datatypes":["eeg"],"demographics":{"subjects_count":23,"ages":[20,21,26,21,28,32,21,23,34,40,22,19,19,24,19,19,20,21,19,22,25,25,19],"age_min":19,"age_max":40,"age_mean":23.434782608695652,"species":null,"sex_distribution":{"f":6,"m":7},"handedness_distribution":null},"experimental_modalities":null,"external_links":{"source_url":"https://openneuro.org/datasets/ds004117","osf_url":null,"github_url":null,"paper_url":null},"funding":["National Institutes of Health NS047293","Swartz Foundation"],"ingestion_fingerprint":"2682d913bbe2544a3e2ecf162ccc9c2f8c606d590d36950b65bb61d595de1789","license":"CC0","n_contributing_labs":null,"name":"Sternberg Working Memory","readme":"## Modified Sternberg Working Memory Experiment\n**Project name:** EEG and working memory\n**Years the project ran:** 2004-05\n**Brief overview of experiment task:** The purpose of this Modified Sternberg task study was to\nexplore source-resolved EEG brain dynamics associated with selectively committing a series of letters to memory,\nthen after a brief maintenance period responding by button press either yes or no to the question of whether\na presented query letter had been in the just-presented set of to-be-memorized letters.\nThe task is a modified version of the classic Sternberg working memory task, with two added features:\n(1) interspersing the sequence of presented (black) letters to be memorized with (green) letters to be ignored,\nand (2) delivering auditory feedback on each trial as to the correctness of the participant response\n(beep = correct, buzz = incorrect).\n**Data collection:** Scalp EEG data were collected from 71 scalp electrode channels,\neach referred to a right mastoid electrode, at a sampling rate of 250 Hz/channel within an\nanalog passband of 0.1 to 100 Hz.\n**Contact person:   Julie Onton <julieonton@gmail.com>, ORCID#:0000-0002-5602-3557.\n**Access information:**  Contributed to OpenNeuro.org and NEMAR.org in BIDS format\nfollowing annotation using HED 8.0.0 in April, 2022.\n**Independent variables:** Letter category (to_memorize, to_ignore);\nnumbers of presented letters to_memorize/to_ignore (3/5, 5/3, 7/1);\nprobe letter category (in/not in the presented set). Note, only letters to be memorized appear as in set probe letters.\n**Dependent variables:**  EEG; button press response latency;  participant response (correct/incorrect).\n**Participant pool:** The dataset includes data collected from 23 healthy young adult subjects\n(7 male, 6 female, 11 unidentified) between the ages of 19 and 40 years of age.\n**Apparatus:** A Neurobehavioral Systems, Inc. EEG system running under Window98 acquired the data.\nThe experiment control program was Presentation (Neurobehavioral Systems, Inc.).\n**Initial setup:** EEG data were collected from 71 channels (69 scalp and two periocular electrodes,\nall referred to right mastoid) with an analog pass band of 0.01 to 100 Hz (SA Instrumentation, San Diego).\nInput impedances were brought under 5 kOhms by careful scalp preparation.\nData for subjects 1-12 was acquired at a sampling rate of 250Hz. The data for subject 14 was acquired at\n1000 Hz and the data for subjects 15-24 was a acquired using a 500 Hz sampling rate.\n**Task organization:**  Data was organized into runs of 25 trials each followed by a rest.\nEach block was a separate run in the BIDS dataset.\n**Task details:** Each trial consisted of the following sequence of events:\n**[Trial initiation]**. After a self-selected, variable delay,\nthe subject initiated the next trial by pressing either response button,\ntriggering the reappearance of the fixation cross.\n**[Letter sequence presentation]**. In these experiments, following a 5s presentation of a central\nfixation cross cue, a series of 8 visual letters (~2 deg of visual angle) were presented at\nscreen center for 1.2s followed by a 0.2s ISI:\n- Either 3, 5, or 7 of these were colored black.\n- The participant was to memorize as letters in this set.\n- The other 5, 3, or 1 letters in the sequence were colored green and participants were to ignore these.\n- The letters were drawn without substitution from the English alphabet (omitting only A, E, I, O, and U).\n- The presentation order of black and green letters was pseudo-random.\n**[Memory maintenance]**. In place of a ninth letter, a dash appeared on the screen to signal the\nbeginning of a Memory Maintenance period lasting between 2 to 4 s.\nDuring this period subjects were to silently rehearse the identities of the memorized letters.\n**[Memory probe]**. A (red) probe letter then appeared, prompting the subject to respond by\npressing one of two buttons (with the thumb or index finger of their dominant hand)\nto indicate whether or not the probe letter had been in the trial?s to-be-memorized letter set.\n**[Response feedback]**. An auditory feedback signal (a confirmatory beep or cautionary buzz),\nthen presented beginning at 400 ms after the button press, informed the subject whether their\nresponse was correct or incorrect. Note: responses in the task were largely correct.\n**[Session time structure]**. Each task session comprised of 3 or 4 task blocks of 25 trials each\nseparated into individual run files.\n**Experiment location**:  Swartz Center for Neural Computation (SCCN), University of California San Diego, La Jolla CA (USA).\n**Note 1**: Results presented in Onton, J., Delorme, A. and Makeig, S., 2005.\nFrontal midline EEG dynamics during working memory. Neuroimage, 27(2), pp.341-356.\n**Note 2**: This paradigm is one of 20 event-related EEG task paradigms selected for replication by the EEGManyLabs project.\nFor details, see https://psyarxiv.com/528nr/. Contact: Yuri Pavlov <pavlovug@gmail.com>.\n**Note 3**: Participant 5 did not have feedback events in the trials.\n**Note 4**: The code subdirectory has several auxilliary files that were produced during\nthe curation process. The curation was done using a series of Jupyter notebooks\nthat are available as run in the code/curation_notebooks subdirectory.\nDuring the running of these curation notebooks information about the status was logged\nusing the HEDLogger. The output of the logging process is in code/curation_logs.\nUpdated versions of the curation notebooks can be found at:\nhttps://github.com/hed-standard/hed-examples/tree/main/hedcode/jupyter_notebooks/dataset_specific_processing/sternberg","recording_modality":["eeg"],"senior_author":"Kay Robbins (curation)","sessions":["01"],"size_bytes":6229874415,"source":"openneuro","study_design":null,"study_domain":null,"tasks":["WorkingMemory"],"timestamps":{"digested_at":"2026-04-22T12:26:08.469695+00:00","dataset_created_at":"2022-05-01T20:28:00.340Z","dataset_modified_at":"2022-06-16T23:21:01.000Z"},"total_files":85,"storage":{"backend":"s3","base":"s3://openneuro.org/ds004117","raw_key":"dataset_description.json","dep_keys":["CHANGES","README","participants.json","participants.tsv","task-WorkingMemory_events.json"]},"nemar_citation_count":2,"computed_title":"Sternberg Working Memory","nchans_counts":[{"val":71,"count":85}],"sfreq_counts":[{"val":250.0,"count":47},{"val":500.0,"count":24},{"val":500.059,"count":11},{"val":1000.0,"count":3}],"stats_computed_at":"2026-04-22T23:16:00.307023+00:00","tags":{"modality":"Visual","pathology":"Healthy","type":"Memory"},"total_duration_s":55670.95302834865,"author_year":"Onton2022","canonical_name":null}}