Different types of feedback change decision criterion and sensitivity differently in perceptual learning

Abstract

In (perceptual) learning, performance improves with practice either by changes in sensitivity or decision criterion. Often, changes in sensitivity are regarded as the appropriate measure of learning while changes in criterion are considered unavoidable nuisances. Very little is known about the distinguishing characteristics of both learning types. Here, we show first that block feedback, which affects sensitivity, does not affect criterion. Second, contrary to changes in sensitivity, changes in decision criterion are limited to the training session and do not transfer overnight. Finally, training with biased trial-wise feedback induces a sensitivity change such that a left offset Vernier may be perceived as a right offset Vernier.

Modeling trial by trial and block feedback in perceptual learning

“…However, without quantitative fitting, simulations of the currently implemented AHRM using the training protocols in asymmetric exposure and feedback reversal conditions predict data patterns (Figure 10) that are qualitatively akin to those shown in Herzog and Fahle (1999)—biased training with false feedback on the smallest left offset leads to decreases in correct labelling of the negative offsets, essentially shifting responses to “right”. The model also appears to be qualitatively consistent with the results in Aberg and Herzog (2012). In the AHRM, these response shifts primarily reflect shifts (biases) in learned weights towards “right” and only secondarily the operation of the bias control unit.…”

“…These asymmetric training effects were the topic of a series of experiment in Herzog and Fahle (1999 in Herzog and Fahle (2006), with the same testing stimuli used in Aberg and Herzog (2012). The asymmetric set included offsets of −15″, −10″, −5″, +10″, and +15″ (arc s), tested with different probabilities and in some conditions the feedback for −5″ was replaced on some or all trials with false feedback indicating a “right” stimulus.…”

“…The asymmetric set included offsets of −15″, −10″, −5″, +10″, and +15″ (arc s), tested with different probabilities and in some conditions the feedback for −5″ was replaced on some or all trials with false feedback indicating a “right” stimulus. Quantitative fitting of the data for the varied training schedules in Herzog and Fahle (1999) and Aberg and Herzog (2012) by the AHRM would require a very extensive new modeling project. Additionally, Herzog & Fahle (1999), report performance only for left offset conditions, and effective model fitting would require more complete data sets.…”

“…Aberg and Herzog (2012), who also used the asymmetric design, argued that block feedback left the decision criterion across blocks unaltered in a line vernier task. In our model, block feedback changes bias weight, and the decision criterion changes slightly on every trial by the product of bias (recency-weighted aggregate response bias) and bias weight (eq.…”

Self-motion perception training: thresholds improve in the light but not in the dark

“…Given that we used a two-alternative forced choice task, hit rate was defined as the number of correct rightward detections divided by the total number of rightward trials, and false alarm rate was defined as number of incorrect rightward responses divided by the total number of leftward trials (Aberg and Herzog 2012). Learning effects during the training phase were assessed by means of the individual regression slopes of d′ as a function of blocks.…”