Cognitive Plasticity and Cortical Modules

Singing accuracy across the lifespan

Although singing is a nearly universal human behavior, many adults consider themselves poor singers and avoid singing based on self-assessment of pitch matching accuracy during singing (here referred to as singing accuracy), in contrast to the uninhibited singing exhibited by children. In this article, I report results that shed light on how singing accuracy changes across the lifespan, using data from a large online sample, including participants ranging from 6 to 99 years old. Results suggest that singing accuracy improves dramatically from childhood to young adulthood, unperturbed by voice changes during adolescence, and remain at a similarly high level for the remainder of life, exhibiting no strong tendency toward age-related decline. Vocal or instrumental musical training has significant positive effects on singing accuracy, particularly in childhood, though there was no evidence for gender differences. Finally, pitch discrimination varied with age similarly to singing accuracy, in support of views that singing accuracy reflects sensorimotor learning. Taken together, these results are consistent with the view that singing accuracy is a learned motor skill that benefits from engagement and can remain a fruitful endeavor into old age.

Benefits of fading in perceptual learning are driven by more than dimensional attention

Individuals learn to classify percepts effectively when the task is initially easy and then gradually increases in difficulty. Some suggest that this is because easy-to-discriminate events help learners focus attention on discrimination-relevant dimensions. Here, we tested whether such attentional-spotlighting accounts are sufficient to explain easy-to-hard effects in auditory perceptual learning. In two experiments, participants were trained to discriminate periodic, frequency-modulated (FM) tones in two separate frequency ranges (300–600 Hz or 3000–6000 Hz). In one frequency range, sounds gradually increased in similarity as training progressed. In the other, stimulus similarity was constant throughout training. After training, participants showed better performance in their progressively trained frequency range, even though the discrimination-relevant dimension across ranges was the same. Learning theories that posit experience-dependent changes in stimulus representations and/or the strengthening of associations with differential responses, predict the observed specificity of easy-to-hard effects, whereas attentional-spotlighting theories do not. Calibrating the difficulty and temporal sequencing of training experiences to support more incremental representation-based learning can enhance the effectiveness of practice beyond any benefits gained from explicitly highlighting relevant dimensions.

Functional relationships for determining similarities and differences in comparative cognition

Pigeons, capuchin monkeys and rhesus monkeys were trained in nearly identical same/different tasks with an expanding 8-item training set and showed qualitatively similar functional relationships: increasing novel-stimulus transfer (i.e., concept learning) as a function of the training-set size and the level of transfer eventually becoming equivalent to baseline training performance. There were also some quantitative functional differences: pigeon transfer increases were more gradual and baseline-equivalent transfer occurred at a larger set size (256 items) than for monkeys (128 items). Other pigeon groups trained at 32 and 64-item initial set sizes showed improved transfer (relative to expanding the 8-item training set), equivalent to the monkey species' transfer at these same training set sizes. This finding of equivalent concept learning over a portion of the functional range (8, 32, and 64 items or 64-4096 training pairs) is discussed in terms of species differences: carryover effects from smaller-set training, evolved neural systems, cognitive and cortical modules, and general distributed learning systems for "higher-order" cognitive abilities.