Two types of learning revealed by evaluation of the best and worst daily performance during auditory‐discrimination training

Performance on many auditory discrimination tasks improves with practice. This learning could result from improvements in fundamental processing capacity (as is implicitly assumed), from improvements in the ability to consistently access already existing capacities, or from a combination of the two. To help distinguish among these types of improvement, we reanalyzed learning data on three basic auditory tasks, examining the best and worst, rather than the mean, thresholds on each of 6–10 days of training. On one task (interaural‐level discrimination), the best and worst thresholds decreased in parallel, indicating an improvement in fundamental processing capacity. On another task (interaural‐time discrimination), the best thresholds remained unchanged but the worst thresholds decreased, suggesting an increased consistency in accessing already existing capacities. Demonstrating a combination of these two types of improvement, on the third task (duration discrimination), both the best and worst thresholds i...