Easy-to-hard effects in perceptual learning depend upon the degree to which initial trials are "easy"

Abstract

Starting perceptual training at easy levels before progressing to difficult levels generally produces better learning outcomes than constantly difficult training does. However, little is known about how "easy" these initial levels should be in order to yield easy-to-hard effects. We compared five levels of initial training block difficulty varying from very easy to hard in two auditory-discrimination learning tasks-a frequency modulation rate discrimination (Experiment 1) and a frequency range discrimination (Experiment 2). The degree of difficulty was based on individualized pretraining ~71% correct discrimination thresholds. Both experiments revealed a sweet spot for easy-to-hard effects. Conditions where initial blocks were either too easy or too difficult produced less benefit than did blocks of intermediate difficulty. Results challenge assumptions that sequencing effects in learning are related to attentional spotlighting of task-relevant dimensions. Rather, they support incremental learning models that account for easy-to-hard effects. Further, the results have implications for how perceptual training regimens should be designed to maximize the benefits of rehabilitative perceptual training.

Keywords: Adaptive training; Fading; Progressive training; Transfer along a continuum.

Figure 1.

(a) Spectrograms of select FM sweep stimuli at rates from 5 octaves/s to 18 octaves/s. (b) Depiction of FM rates that would be presented under each condition for a participant with a threshold of .5 octaves/s.

Figure 2.

(a) Accuracy (A′) across training blocks for all groups in Experiment 1. Error bars show standard error of the mean (SEM). (b) Accuracy (A′) in the test for all groups. Error bars show SEM. (c) Linear and quadratic contrasts. Error bars show 90% confidence intervals according to a null hypothesis distribution generated using a permutation procedure (see text).

Figure 3.

(a) Accuracy (A′) across training blocks for all groups. In Experiment 2 Error bars show standard error of the mean (SEM). (b) Accuracy (A′) in the test for all groups. Error bars show SEM. (c) Linear and quadratic contrasts. Error bars show 90% confidence intervals according to a null hypothesis distribution generated using a permutation procedure (see text).