Startle reflex activation is related to early response triggering and is indicative of an alternate response initiation pathway
Bibliographic record
Abstract
The presentation of a loud, startling acoustic stimulus in a simple reaction time (RT) task has been shown to substantially decrease RT. This so called StartReact effect has been attributed to early and involuntary response triggering due to activation of the startle reflex pathway. However, the relationship between the startle reflex, response triggering, and latency of the response is not fully understood. The purpose of the current study was to examine the conditions under which a prepared response can be triggered by an auditory stimulus. Participants performed a simple RT wrist extension task in response to a visual go-signal. On selected trials, an auditory stimulus of different intensities (80dB, 100dB, 110dB, 120dB) was presented either 300ms or 1000ms prior to the visual go. The presence/absence of a startle reflex was determined by activation of the sternocleidomastoid (SCM+/SCM-), and response triggering was defined as EMG onset occurring within 300ms of the auditory stimulus. As expected, the incidence of SCM+ trials was higher with increasing intensity and later presentation of the auditory stimulus. When SCM activation was observed, the incidence of response triggering was much higher across all intensities ?100dB, and these responses exhibited shorter RT latency than those triggered in the absence of SCM activation. Conversely, when responses occurred in response to the visual go, RT latencies were similar across all conditions. Together, these results suggest that the presence of SCM activation is an important marker for response triggering and is indicative of a separate and faster response initiation pathway.Acknowledgments: This research was supported by the Natural Sciences and Engineering Research Council of Canada and the Ontario Ministry of Research, Innovation and Science.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot 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.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".