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Record W2147917782 · doi:10.1255/jnirs.1056

Haemodynamic Responses to Radial Motion in the Visual Cortex

2013· article· en· W2147917782 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueJournal of Near Infrared Spectroscopy · 2013
Typearticle
Languageen
FieldMedicine
TopicOptical Imaging and Spectroscopy Techniques
Canadian institutionsUniversity of Waterloo
Fundersnot available
KeywordsVisual cortexHaemodynamic responseStimulus (psychology)HemodynamicsFunctional near-infrared spectroscopyLuminanceStimulationNeuroscienceAudiologyPhysicsMedicinePsychologyOpticsAnesthesiaInternal medicineHeart rateCognitionBlood pressure

Abstract

fetched live from OpenAlex

Functional near-infrared spectroscopy (fNIRS) is an optical imaging technique that relies on emitting near-infrared light into cortical tissue to measure changes in haemoglobin concentrations as a result of stimulation. The purpose of this study was to observe haemodynamic changes in response to moving stimuli over the primary visual cortex. The test stimuli were radially expanding and contracting concentric gratings and the control stimulus was a matched stationary pattern. A two-channel oximeter (Oxiplex TS) was used to record changes in oxyhaemoglobin (HbO), de-oxyhaemoglobin (Hb) and total haemoglobin concentrations (THb). An increase in haemodynamic activation was observed 20s after the onset of motion and maintained for up to 20s following motion offset (30s time window). This was compared to a time window of 10s before the offset of the stationary presentation. Differences between expanding and contracting motion did not achieve significance at any of the locations. However, a significantly larger HbO response was observed across the 30s time window when compared to the baseline window at both occipital locations. Preliminary results from more temporal locations also showed a similar trend. It is suggested that the delayed rise in HbO levels could be due to an inconsistent maintenance of luminance and contrast-related features of the moving stimuli in V1 receptive fields. Furthermore, motion-after effects could have contributed to delaying the drop to baseline levels. The current study has shown some evidence that fNIRS can be used to record haemodynamic responses to moving stimuli from the visual cortex. We suggest that longer durations of randomised moving, stationary and grey screen presentations would be useful in teasing apart pure motion responses and after-effects. fNIRS could also potentially be used to investigate haemodynamic changes in disorders such as amblyopia that present with motion processing deficits.

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.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.858
Threshold uncertainty score0.443

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.001
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.012
GPT teacher head0.329
Teacher spread0.318 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it