The easy-to-hard effect in human (Homo sapiens) and rat (Rattus norvegicus) auditory identification.

Abstract

The authors examined whether progressively training humans and rats to perform a difficult auditory identification task led to larger improvements than extensive training with highly similar sounds (the easy-to-hard effect). Practice improved humans' ability to distinguish sounds regardless of the training regimen. However, progressively trained subjects were more accurate and showed more generalization, despite significantly less training with the stimuli that were the most difficult to distinguish. Rats showed less capacity to improve with practice but still benefited from progressive training. These findings indicate that transitioning from an easier to a more difficult task during training can facilitate, and in some cases may be essential for, auditory perceptual learning. The results are not predicted by an explanation that assumes interaction of generalized excitation and inhibition but are consistent with a hierarchical account of perceptual learning in which the representational precision required to distinguish stimuli determines the mechanisms engaged during learning.

Perceptual learning of time-compressed and natural fast speech

“…RHT also predicts that task difficulty of a preceding task affects learning in the subsequent task. Transfer of learning occurs when an easy condition is followed by a more difficult task, but not when a difficult task is followed by an easier task ͑Ahissar and Hochstein, 1997; Liu et al, 2008;Pavlovskaya and Hochstein, 2004͒. Our results comply with this prediction, as we observed task improvement for the natural fast condition ͑the more difficult task͒ when it was preceded by the time-compressed condition ͑the easier task͒, but not when the natural fast condition preceded the timecompressed condition.…”

Auditory discrimination learning and knowledge transfer in mice depends on task difficulty

“…Data from humans indicate no perceptual generalization and knowledge transfer across sounds from different perceptual classes and, therefore, no performance benefit in discrimination when switching the sounds between the classes in a discrimination task (3,5,20,27). This interpretation explains why we did not see a beneficial effect when switching from the easy PT to the hard AM discrimination task (Fig.…”

“…1A). Because the stimulus classes in the two tasks were different, human studies suggest that the benefit (hard-to-easy effect) was not based on knowledge of or generalization across stimuli (3,5,20,27) but rather was based on implicitly learned information integration (30,31). Integration of information about the stimuli, the procedural context, and the acquired cognitive skills in the shuttle-box seems to be the key for understanding the curves of discrimination performance of our mice in Fig.…”

“…cognitive skill learning | go/no-go paradigm | hard-to-easy effect | shuttlebox | stimulus generalization C omplex forms of auditory learning, such as generalization of stimuli within and across physical categories or transfer of knowledge from one stimulus discrimination task to another, are known from humans (1-6) but rarely have been investigated in other mammals (5,7,8). Research in mammalian models is important, however, for an in-depth understanding of neural mechanisms and the genetics of learning abilities and performances.…”

Effects of progressively increasing the difficulty of training on sensitivity and strategic factors in olive oil tasting

“…Analyzing any other effects on this level may contribute to a better understanding of the phenomena, and consequently to optimize potential applications. We are not aware of any study analyzing the effect of progressive training on strategic aspects, even when recent works have implicitly pointed out its relevance by using sensitivity indexes that are asserted to dissociate the potential effects of these strategic aspects (see for example Liu, Mercado, Church, & Orduña, 2008).…”