EEG microstates during visually guided reaching
Bibliographic record
Abstract
The notion that vision's importance in controlling goal-directed reaching movements has been experimentally validated (Woodworth, 1899). Functional MRI and rTMS work has subsequently confirmed that the posterior parietal cortex (PPC) are important for the control of visually guided movements (Culham and Kanwisher, 2001, Desmurget et al, 1999). The temporal resolution is inappropriate to study the cortical dynamics of reaching movements. Therefore, this investigation examined the activation dynamics of movement planning and control as measured by electroencephalography (EEG). Participants completed reaching movements during full-vision (FV), no-vision-delayed (NV) or open-loop (OL). Event-related potential analysis segmented with respect to peak velocity (PV) yielded differences in visual and motor areas following PV. To generate an overall evaluation of the activation across time, ERP waveforms were submitted to a space-oriented field clustering approach (Tunik et al, 2008) to determine epochs of semi-stable field configurations (i.e. microstates) throughout the planning/control of reaches. The results of this micro-state analysis showed that regardless of visual condition, the planning and initiation of movement is characterized by two state transitions: an activation pattern dominated by increasing primary-visual and motor activation (FCz, Oz). NV remained in this early movement state and did not enter any control-based state. During FV, activation shifted following PV to an activation consistent with dorsal (contralateral PPC, frontal and 1o visual areas) guidance of movement. OL transitioned into a bilateral temporal (presumably memory-guided) mode of control that did not exhibit primary visual activation. This had been expected of NV. Thus, even though previous fMRI studies have correctly identified important structures for the control of movement across different visual conditions, they have lacked the temporal resolution to elucidate the pattern of functioning across visually guided reaching movements.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".