Early Cortical Sensitivity and Speeded Target Selection Underlie Incidentally Learned Prioritization of Visual Features.

Adaptive behavior relies on prioritizing relevant sensory information, and decades of research have shown that current task goals and stimulus saliency influence this prioritization. Recent behavioral work indicates that incidental experience with frequently relevant locations or nonspatial features also shapes behavioral prioritization. The present study investigates the neural processing stages affected by incidental learning of nonspatial visual features. We recorded neural activity with high temporal resolution using electroencephalography while human participants (female and male) searched for visual targets that had predictable features (i.e., that appeared more frequently in a particular color). We found that incidental learning of the statistical structure was accompanied by an early differentiation of neural activity for relevant compared with irrelevant features beginning at ∼120 ms post stimulus onset, followed by an earlier-onset selection of the target item, as indexed by a latency shift of the N2pc (∼200 ms), and changes in later memory and response-related processes, marked by amplitude modulations of the LPC (>400 ms). Importantly, the magnitude of the effects across all three neural measures strongly tracked individual differences in the behavioral benefits of learned prioritization, suggesting that successful learning of feature regularities depends on modulating the flow of information across multiple processing stages.