Musicians' working memory for tones, words, and pseudowords

Enhancement of Processing Capabilities of Hippocampus Lobe: A P300 Based Event Related Potential Study

Background and Objectives

The influence of music training on different areas of the brain has been extensively researched, but the underlying neurobehavioral mechanisms remain unknown. In the present study, the effects of training for more than three years in Carnatic music (an Indian form of music) on the discrimination ability of different areas of the brain were tested using P300 analysis at three electrode placement sites.

Subjects and Methods

A total of 27 individuals, including 13 singers aged 16-30 years (mean±standard deviation, 23±3.2 years) and 14 non-singers aged 16-30 years (mean age, 24±2.9 years), participated in this study. The singers had 3-5 years of formal training experience in Carnatic music. Cortical activities in areas corresponding to attention, discrimination, and memory were tested using P300 analysis, and the tests were performed using the Intelligent Hearing System.

Results

The mean P300 amplitude of the singers at the Fz electrode placement site (5.64±1.81) was significantly higher than that of the non-singers (3.85±1.60; t(25)=3.3, p<0.05). The amplitude at the Cz electrode placement site in singers (5.90±2.18) was significantly higher than that in non-singers (3.46±1.40; t(25)=3.3, p<0.05). The amplitude at the Pz electrode placement site in singers (4.94±1.89) was significantly higher than that in non-singers (3.57±1.50; t(25)=3.3, p<0.05). Among singers, the mean P300 amplitude was significantly higher in the Cz site than the other placement sites, and among non-singers, the mean P300 amplitude was significantly higher in the Fz site than the other placement sites, i.e., music training facilitated enhancement of the P300 amplitude at the Cz site.

Conclusions

The findings of this study suggest that more than three years of training in Carnatic singing can enhance neural coding to discriminate subtle differences, leading to enhanced discrimination abilities of the brain, mainly in the generation site corresponding to Cz electrode placement.

Voice Quality and Auditory Processing in Subjects with and Without Musical Experience

INTRODUCTION

The relationship between voice and auditory processing is complex and has aroused increasing scientific interest in the last decades. Little is known about the relationship between voice quality and auditory processing in individuals with and without musical experience.

OBJECTIVES

To assess voice quality and auditory processing in subjects with and without musical experience.

METHODS

Total 120 individuals were split into three groups: GS = singers (N = 47), GI = instrumentalists (N = 43), and NM = nonmusicians (N = 30); group GS was subdivided into GS = 20 singers only and GSI = 27 singers and instrumentalists at the same time. Subjects were undertaken vocal assessment by means of Perceptual Assessment of voice recording followed by self-assessment of a potential voice problem using the Brazilian validated version of the Voice Symptom Scale (VoiSS) (Escala de Sintomas Vocais - ESV). The central auditory processing was carried out following such temporal processing tests: Frequency Pattern Test (FPT), Random Gap Detection Test (RGDT), and auditory-perceptual analysis of distorted speech as indicated: Synthetic Sentence Identification (SSI) test, with Ipsilateral Competing Message.

RESULTS

GSI reported a higher number of voice symptoms compared to the other groups for the VoiSS. Throughout the groups, most individuals did not present voice disorders and, when presented, were mild. Subgroup GSI showed the best auditory abilities of temporal ordering for the FPT-Humming and FPT-Verbal, whereas NM had the worst performance. Negligible correlation strength alone was found between the different central auditory processing tests, the overall degree of vocal deviation in the auditory-perceptual analysis of voice quality, and the total score of the Voice Symptom Scale protocol.

CONCLUSION

The voice quality of musicians and nonmusicians was correlated with their auditory processing; although with negligible strength. It was verified that singers-instrumentalist reported more voice symptoms compared to the other groups. Despite the large variation throughout the groups concerning auditory processing, musicians, especially singers-instrumentalists, have shown better auditory abilities of temporal ordering, suggesting that musical training and experience may account for such performance.

Pitch-specific contributions of auditory imagery and auditory memory in vocal pitch imitation

Vocal imitation guides both music and language development. Despite the developmental significance of this behavior, a sizable minority of individuals are inaccurate at vocal pitch imitation. Although previous research suggested that inaccurate pitch imitation results from deficient sensorimotor associations between pitch perception and vocal motor planning, the cognitive processes involved in sensorimotor translation are not clearly defined. In the present research, we investigated the roles of basic cognitive processes in the vocal imitation of pitch, as well as the degree to which these processes rely on pitch-specific resources. In the present study, participants completed a battery of pitch and verbal tasks to measure pitch perception, pitch and verbal auditory imagery, pitch and verbal auditory short-term memory, and pitch imitation ability. Information on participants' music background was collected, as well. Pitch imagery, pitch short-term memory, pitch discrimination ability, and musical experience were unique predictors of pitch imitation ability. Furthermore, pitch imagery was a partial mediator of the relationship between pitch short-term memory and pitch imitation ability. These results indicate that vocal imitation recruits cognitive processes that rely on at least partially separate neural resources for pitch and verbal representations.

Electrical Neuroimaging of Music Processing in Pianists With and Without True Absolute Pitch

True absolute pitch (AP), labeling of pitches with semitone precision without a reference, is classically studied using isolated tones. However, AP is acquired and has its function within complex dynamic musical contexts. Here we examined event-related brain responses and underlying cerebral sources to endings of short expressive string quartets, investigating a homogeneous population of young highly trained pianists with half of them possessing true-AP. The pieces ended regularly or contained harmonic transgressions at closure that participants appraised. Given the millisecond precision of ERP analyses, this experimental plan allowed examining whether AP alters music processing at an early perceptual, or later cognitive level, or both, and which cerebral sources underlie differences with non-AP musicians. We also investigated the impact of AP on general auditory cognition. Remarkably, harmonic transgression sensitivity did not differ between AP and non-AP participants, and differences for auditory cognition were only marginal. The key finding of this study is the involvement of a microstate peaking around 60 ms after musical closure, characterizing AP participants. Concurring sources were estimated in secondary auditory areas, comprising the planum temporale, all transgression conditions collapsed. These results suggest that AP is not a panacea to become a proficient musician, but a rare perceptual feature.

Irrelevant sound interference on phonological and tonal working memory in musicians and nonmusicians

BACKGROUND

Working memory refers to the cognitive system responsible for the temporary storage and maintenance of information, but it remains controversial whether overlapping processes underlie the temporary retention of verbal and musical information such as words and tones.

METHODS

Participants with little or no musical training (n = 22) and professional musicians (n = 21) were administered four memory tasks. Two tasks (tone sequence recognition and pseudoword sequence recall) aimed at comparing groups' performance for tonal or phonological material separately. Other two memory tasks investigated pseudoword and tone recognition under three conditions during the retention interval (silence, irrelevant words, or irrelevant tones).

RESULTS

Musicians were better than nonmusicians in tone sequence recognition but not in pseudoword sequence recall. There were no interference effects of irrelevant tones or words on pseudoword recognition, and only irrelevant tones significantly interfered with tone recognition.

CONCLUSIONS

Our results offer further support that tone recognition is specifically impaired by irrelevant tones, but irrelevant words did not disrupt pseudoword or tone recognition. Although these results do not reflect a double-dissociation pattern between phonological and tonal working memory, they provide evidence that temporary retention of tonal information is subject to specific tonal interference, indicating that working memory for tones involves specific processes.

Musical and verbal short-term memory: insights from neurodevelopmental and neurological disorders

Auditory short-term memory (STM) is a fundamental ability to make sense of auditory information as it unfolds over time. Whether separate STM systems exist for different types of auditory information (music and speech, in particular) is a matter of debate. The present paper reviews studies that have investigated both musical and verbal STM in healthy individuals and in participants with neurodevelopmental and neurological disorders. Overall, the results are in favor of only partly shared networks for musical and verbal STM. Evidence for a distinction in STM for the two materials stems from (1) behavioral studies in healthy participants, in particular from the comparison between nonmusicians and musicians; (2) behavioral studies in congenital amusia, where a selective pitch STM deficit is observed; and (3) studies in brain-damaged patients with cases of double dissociation. In this review we highlight the need for future studies comparing STM for the same perceptual dimension (e.g., pitch) in different materials (e.g., music and speech), as well as for studies aiming at a more insightful characterization of shared and distinct mechanisms for speech and music in the different components of STM, namely encoding, retention, and retrieval.

Tone series and the nature of working memory capacity development

Recent advances in understanding visual working memory, the limited information held in mind for use in ongoing processing, are extended here to examine auditory working memory development. Research with arrays of visual objects has shown how to distinguish the capacity, in terms of the number of objects retained, from the precision of the object representations. We adapt the technique to sequences of nonmusical tones, in an investigation including children (6-13 years, N = 84) and adults (26-50 years, N = 31). For each series of 1 to 4 tones, the participant responded by using an 80-choice scale to try to reproduce the tone at a queried serial position. Despite the much longer-lasting usefulness of sensory memory for tones compared with visual objects, the observed tone capacity was similar to previous findings for visual capacity. The results also constrain theories of childhood working memory development, indicating increases with age in both the capacity and the precision of the tone representations, similar to the visual studies, rather than age differences in time-based memory decay. The findings, including patterns of correlations between capacity, precision, and some auxiliary tasks and questionnaires, establish capacity and precision as dissociable processes and place important constraints on various hypotheses of working memory development. (PsycINFO Database Record

The effect of beam slope on the perception of melodic contour

Musical score reading is a complex task, which involves attending and interpreting multiple visual constituents that are graphically congested. The present investigation examined the 'beam', which although consistently found in music notation, is typically considered as providing no more information than marking metric boundaries (i.e., chunking). However, we provide evidence here that beams enhance visual perception of contour. In Study 1, a Stroop-like paradigm was used in which participants were required to judge the direction of notes or the beam in a compound figure; the two dimensions were either congruent or incongruent. A congruency effect was observed in both tasks, confirming that both notes and beam are processed automatically during score reading. In Study 2, an additional auditory stimulus was presented. The results not only replicated the findings of Study 1, but showed that beams affect both visual and auditory perception. Finally, group differences surfaced: musicians were more affected by the direction of notes than non-musicians when attending to beams, but the effect of beams on judging note direction was comparable in both groups. The implications for understanding musical score reading - specifically issues related to melodic contour - are discussed.

Music training is associated with cortical synchronization reflected in EEG coherence during verbal memory encoding

Music training can improve cognitive functions. Previous studies have shown that children and adults with music training demonstrate better verbal learning and memory performance than those without such training. Although prior studies have shown an association between music training and changes in the structural and functional organization of the brain, there is no concrete evidence of the underlying neural correlates of the verbal memory encoding phase involved in such enhanced memory performance. Therefore, we carried out an electroencephalography (EEG) study to investigate how music training was associated with brain activity during the verbal memory encoding phase. Sixty participants were recruited, 30 of whom had received music training for at least one year (the MT group) and 30 of whom had never received music training (the NMT group). The participants in the two groups were matched for age, education, gender distribution, and cognitive capability. Their verbal and visual memory functions were assessed using standardized neuropsychological tests and EEG was used to record their brain activity during the verbal memory encoding phase. Consistent with previous studies, the MT group demonstrated better verbal memory than the NMT group during both the learning and the delayed recall trials in the paper-and-pencil tests. The MT group also exhibited greater learning capacity during the learning trials. Compared with the NMT group, the MT group showed an increase in long-range left and right intrahemispheric EEG coherence in the theta frequency band during the verbal memory encoding phase. In addition, their event-related left intrahemispheric theta coherence was positively associated with subsequent verbal memory performance as measured by discrimination scores. These results suggest that music training may modulate the cortical synchronization of the neural networks involved in verbal memory formation.

Attentional flexibility and memory capacity in conductors and pianists

Individuals with high working memory (WM) capacity also tend to have better selective and divided attention. Although both capacities are essential for skilled performance in many areas, evidence for potential training and expertise effects is scarce. We investigated the attentional flexibility of musical conductors by comparing them to equivalently trained pianists. Conductors must focus their attention both on individual instruments and on larger sections of different instruments. We studied students and professionals in both domains to assess the contributions of age and training to these skills. Participants completed WM span tests for auditory and visual (notated) pitches and timing durations, as well as long-term memory tests. In three dichotic attention tasks, they were asked to detect small pitch and timing deviations from two melodic streams presented in baseline (separate streams), selective-attention (concentrating on only one stream), and divided-attention (concentrating on targets in both streams simultaneously) conditions. Conductors were better than pianists in detecting timing deviations in divided attention, and experts detected more targets than students. We found no group differences for WM capacity or for pitch deviations in the attention tasks, even after controlling for the older age of the experts. Musicians' WM spans across multimodal conditions were positively related to selective and divided attention. High-WM participants also had shorter reaction times in selective attention. Taken together, conductors showed higher attentional flexibility in successfully switching between different foci of attention.