Changes in Auditory Cortex Parallel Rapid Perceptual Learning

Abstract

Learning perceptual skills is characterized by rapid improvements in performance within the first hour of training (fast perceptual learning) followed by more gradual improvements that take place over several daily practice sessions (slow perceptual learning). Although it is widely accepted that slow perceptual learning is accompanied by enhanced stimulus representation in sensory cortices, there is considerable controversy about the neural substrates underlying early and rapid improvements in learning perceptual skills. Here we measured event-related brain potentials while listeners were presented with 2 phonetically different vowels. Listeners' ability to identify both vowels improved gradually during the first hour of testing and was paralleled by enhancements in an early evoked response ( approximately 130 ms) localized in the right auditory cortex and a late evoked response ( approximately 340 ms) localized in the right anterior superior temporal gyrus and/or inferior prefrontal cortex. These neuroplastic changes depended on listeners' attention and were preserved only if practice was continued; familiarity with the task structure (procedural learning) was not sufficient. We propose that the early increases in cortical responsiveness reflect goal-directed changes in the tuning properties of auditory neurons involved in parsing concurrent speech signals. Importantly, the neuroplastic changes occurred rapidly, demonstrating the flexibility of human speech segregation mechanisms.

Suppression of Otoacoustic Emissions Evoked by White Noise and Speech Stimuli

“…Other studies demonstrated growing evidence that the adult auditory cortex is a dynamic and adaptive processing center. This has been shown in auditory perceptual learning studies, in which long-lasting neuronal changes were observed in the auditory cortex of animals [45,46] and human beings [47,48] after intensive auditory training.…”

“…The authors assessed 11 adults with normal thresholds, using three suppressor stimuli: clicks, narrow band noise, and pure tones. It was found that the click and pure-tone stimuli were the most and least efective suppressors, respectively [47]. Speech, however, was not considered.…”

Effects of Long-Term Speech-in-Noise Training in Air Traffic Controllers and High Frequency Suppression. A Control Group Study

“…Current models propose that perceptual learning in adults depends strongly on top-down influences such as attention, reward, and task relevance. This demonstrates that the adult AC is a dynamic and adaptive processing center [9][10][11][12][13][14][15][16][17][18] . Natural auditory training occurs in job sectors involving frequent daily radio communications.…”

How musical are music video game players?

“…Although preexisting differences can influence musical activity and abilities, it is also clear that auditory abilities and their underlying neural substrates are highly malleable due to experience (e.g., Alain et al, 2007;Lappe et al, 2008). Thus, it is likely that although differences in personality or preexisting perceptual abilities might lead some individuals to choose to learn a musical instrument or play music video games, the actual experience of practicing these activities is what leads to differences in music aptitude.…”

“…The past two decades have nevertheless witnessed an abundance of reports suggesting that "musicians" outperform "nonmusicians" on measures of sensory, cognitive, and motor functions (Hannon & Trainor, 2007;Strait & Kraus, 2014). Studies with tightly controlled learning situations have demonstrated that remarkable behavioral and neural changes can occur as a result of auditory learning (e.g., Alain, Snyder, He, & Reinke, 2007;Lappe, Herholz, Trainor, & Pantev, 2008), or even passive exposure to musical stimuli (e.g., Hannon & Trehub, 2005). However, other evidence suggests that personality differences predict who undertakes music training and who does not (e.g., Corrigall, Schellenberg, & Misura, 2013).…”