Revisiting the electrophysiological correlates of feature analysis during visual search
Bibliographic record
Abstract
Seminal event-related potential (ERP) studies of visual search revealed the componentry associated with the analysis of target and nontarget singletons that appear in an otherwise uniform array of identical items. The ERP componentry included an anterior N2, posterior bilateral N2 (N2pb), posterior contralateral N2 (N2pc), a P3b, and an occipital P3 (later called the singleton detection positivity, SDP). At about the same time, seminal reaction time results indicated that individuals can use a feature-based strategy or a salience-based strategy to find a fixed-feature singleton. Here, we varied the task parameters to revisit the electrophysiological correlates of different visual search strategies. The search array contained 16 small vertical blue bars or 15 small vertical blue bars and one of the following singletons: a horizontal blue bar (small or large) or a vertical yellow bar (small or large). In Experiment 1, participants indicated whether one pre-specified target singleton was present (20% of trials) or absent (80%), and in Experiment 2, participants indicated whether the array contained any singleton (20%) or not (80%). Thus, only participants in Experiment 1 needed to differentiate the target from other nontarget singletons. Targets elicited an N2pc and an anterior N2 in both experiments, but the latter was larger in Experiment 2. Interestingly, the N2pb appeared to reflect volume conduction from the anterior scalp. The SDP was difficult to isolate because the low probability of target-present trials led to a large P3b at nearby electrodes. Finally, in Experiment 1, a late anterior negativity was elicited by nontarget singletons that resembled the target (e.g., large yellow bar when participants searched for a small yellow bar). No late anterior negativity was evident in response to nontarget singletons that were easily distinguished from the target, suggesting that this component is associated with conflict resolution in medial frontal cortex.
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 | 0.001 | 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 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".