A neural population selective for song in human auditory cortex

Encoding of melody in the human auditory cortex

Melody is a core component of music in which discrete pitches are serially arranged to convey emotion and meaning. Perception varies along several pitch-based dimensions: (i) the absolute pitch of notes, (ii) the difference in pitch between successive notes, and (iii) the statistical expectation of each note given prior context. How the brain represents these dimensions and whether their encoding is specialized for music remains unknown. We recorded high-density neurophysiological activity directly from the human auditory cortex while participants listened to Western musical phrases. Pitch, pitch-change, and expectation were selectively encoded at different cortical sites, indicating a spatial map for representing distinct melodic dimensions. The same participants listened to spoken English, and we compared responses to music and speech. Cortical sites selective for music encoded expectation, while sites that encoded pitch and pitch-change in music used the same neural code to represent equivalent properties of speech. Findings reveal how the perception of melody recruits both music-specific and general-purpose sound representations.

Treatment effects of adjunct group music therapy in inpatients with chronic schizophrenia: a systematic review

Introduction

Pharmacological treatment may be effective for treating positive symptoms of schizophrenia; no evidence of clinically significant effects on negative and cognitive symptoms, social and behavioral functioning. This review investigated treatment outcomes of multiple (at least four sessions in 4 weeks) group music therapy sessions adjunct to standard care in inpatients with chronic schizophrenia.

Methods

A systematic review search of five electronic medical and psychological databases conducted using keywords "music therapy" and "schizophrenia" up to December 2021. Screening was performed for published articles on any adjunct multiple group music therapy (four sessions in 4 weeks minimum) adjunct to "treatment as usual" for inpatients with "chronic" schizophrenia. All study outcomes were all included. Risk of bias of all studies was assessed.

Results

1160 articles were screened, and 13 randomized controlled trials (RCTs) with a total of 1,114 inpatients were included. Ten RCTs reported open group sessions with active structured music making (ASMM) combining passive music listening (PML) and/or active singing, playing instruments, and improvisations while three other studies applied PML only. Four studies reported significant outcomes for both positive and negative symptoms. Ten of the thirteen studies recorded significant improvements in negative symptoms, behavioral and social functioning. Lasting significant effects were found in a longitudinal RCT with 272 samples evaluated unguided pre-recorded PML as a coping method lasting up to six months and similar results found in another two longitudinal RCTs. Secondary outcomes measured cognition, mood, social interest and function, self-care ability, interpersonal relationships, and QoL all showed significant outcomes. The significance level for pre-post intervention and between-group measures ranged from p < 0.001 to p < 0.05. No negative effects were reported in any studies.

Conclusion

Evidence from this review suggests rehabilitation with adjunctive regular PML or combined ASMM in group settings may provide therapeutic engagement, contributing to improvements in social interest and participation. PML is low-cost and non-invasive therapy. Enhancing overall QoL as one type of psychosocial therapy. More rigorous longitudinal studies with larger sample sizes are needed to investigate whether regular long-term individual PML and active group music therapy have the same significant treatment effects as coping and rehabilitation strategies.

Encoding of melody in the human auditory cortex

Melody is a core component of music in which discrete pitches are serially arranged to convey emotion and meaning. Perception of melody varies along several pitch-based dimensions: (1) the absolute pitch of notes, (2) the difference in pitch between successive notes, and (3) the higher-order statistical expectation of each note conditioned on its prior context. While humans readily perceive melody, how these dimensions are collectively represented in the brain and whether their encoding is specialized for music remains unknown. Here, we recorded high-density neurophysiological activity directly from the surface of human auditory cortex while Western participants listened to Western musical phrases. Pitch, pitch-change, and expectation were selectively encoded at different cortical sites, indicating a spatial code for representing distinct dimensions of melody. The same participants listened to spoken English, and we compared evoked responses to music and speech. Cortical sites selective for music were systematically driven by the encoding of expectation. In contrast, sites that encoded pitch and pitch-change used the same neural code to represent equivalent properties of speech. These findings reveal the multidimensional nature of melody encoding, consisting of both music-specific and domain-general sound representations in auditory cortex.

Teaser

The human brain contains both general-purpose and music-specific neural populations for processing distinct attributes of melody.