Common vs. independent limb control in sequential vertical aiming: Extending or reversing target-aiming movements
Bibliographic record
Abstract
In discrete aiming, adult performers optimize their movement to maximize speed and accuracy, and to minimize energy expenditure. This research was designed to examine trajectory regulation in sequential vertical aiming. In Experiment 1, participants performed single up and down aiming movements, as well as sequential aiming movements that involved extending the initial movement to a second target. Of interest was how the first aiming movement was organized to accommodate the second aiming movement. Overall, participants exhibited shorter movement times and times to peak acceleration and velocity when moving up. Peak acceleration was also greater for upward aims, but only for the single target trials. Downward movements were spatially more variable. Analyses examining the relationship between kinematic events in the first and second aiming movements revealed positive r-values when moving up but little relationship when moving down. These results suggest that sequential upward movements are planned together, while downward aiming involves more concurrent control and the independent regulation of the two movement components. In Experiment 2, the experimental design was similar except that in the sequential aiming condition participants reversed the direction of their first movement, thus returning to the home position. Consistent with previous research, participants exhibited shorter movement times and higher peak accelerations and velocities under two-target than one-target conditions. Correlational analyses revealed positive relationships between movement one and two for both up and down initial movements. For up movements, there was a stronger relationship between the peak acceleration in movement one and kinematic events in movement two, while for down movements, late markers co-varied with movement two. These findings are consistent with the notion that, in a reversal movement, the two components are organized together to optimize time and energy by using the same muscular forces to decelerate movement one and accelerate movement two.Acknowledgments: This research was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC).
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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 | 0.001 | 0.004 |
| 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 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".