Can rhythm-mediated reward boost learning, memory, and social connection? Perspectives for future research.

Studies of rhythm processing and of reward have progressed separately, with little connection between the two. However, consistent links between rhythm and reward are beginning to surface, with research suggesting that synchronization to rhythm is rewarding, and that this rewarding element may in turn also boost this synchronization. The current mini review shows that the combined study of rhythm and reward can be beneficial to better understand their independent and combined roles across two central aspects of cognition: 1) learning and memory, and 2) social connection and interpersonal synchronization; which have so far been studied largely independently. From this basis, it is discussed how connections between rhythm and reward can be applied to learning and memory and social connection across different populations, taking into account individual differences, clinical populations, human development, and animal research. Future research will need to consider the rewarding nature of rhythm, and that rhythm can in turn boost reward, potentially enhancing other cognitive and social processes.

Near and far transfer: Is music special?

Far transfer rarely occurs, and a recent meta-analysis suggests that music is no exception. The overall effect of musical training on cognition was claimed to be null when considering studies with active control groups or implemented randomization procedures (Sala & Gobet, Memory & Cognition, 48: 1429-1441, 2020). Using the authors' data file and program ( https://osf.io/rquye ), we did not confirm the effect of randomization, and we demonstrated that their conclusion is based in part on the failure to differentiate near and far transfer, with near transfer effect sizes being selectively excluded for the musical training group studies, but not for the active control group studies. Reanalyzing their data file resulted in a significant effect size (g = .234), and also provided new evidence that far-transfer effects of musical training can challenge near-transfer effects of linguistic training. Music is a recreational activity that may be special in allowing for small but statistically significant far-transfer effects.

Listeners with congenital amusia are sensitive to context uncertainty in melodic sequences.

In typical listeners, the perceptual salience of a surprising auditory event depends on the uncertainty of its context. For example, in melodies, pitch deviants are more easily detected and generate larger neural responses when the context is highly predictable than when it is less so. However, it is not known whether amusic listeners with abnormal pitch processing are sensitive to the degree of uncertainty of pitch sequences and, if so, whether they are to a different extent than typical non-musician listeners. To answer this question, we manipulated the uncertainty of short melodies while participants with and without congenital amusia underwent EEG recordings in a passive listening task. Uncertainty was manipulated by presenting melodies with different levels of complexity and familiarity, under the assumption that simpler and more familiar patterns would enhance pitch predictability. We recorded mismatch negativity (MMN) responses to pitch, intensity, timbre, location, and rhythm deviants as a measure of auditory surprise. In both participant groups, we observed reduced MMN amplitudes and longer peak latencies for all sound features with increasing levels of complexity, and putative familiarity effects only for intensity deviants. No significant group-by-complexity or group-by-familiarity interactions were detected. However, in contrast to previous studies, pitch MMN responses in amusics were disrupted in high complexity and unfamiliar melodies. The present results thus indicate that amusics are sensitive to the uncertainty of melodic sequences and that preattentive auditory change detection is greatly spared in this population across sound features and levels of predictability. However, our findings also hint at pitch-specific impairments in this population when uncertainty is high, thus suggesting that pitch processing under high uncertainty conditions requires an intact frontotemporal loop.

Implicit learning of two artificial grammars.

This study investigated the implicit learning of two artificial systems. Two finite-state grammars were implemented with the same tone set (leading to short melodies) and played by the same timbre in exposure and test phases. The grammars were presented in separate exposure phases, and potentially acquired knowledge was tested with two experimental tasks: a grammar categorization task (Experiment 1) and a grammatical error detection task (Experiment 2). Results showed that participants were able to categorize new items as belonging to one or the other grammar (Experiment 1) and detect grammatical errors in new sequences of each grammar (Experiment 2). Our findings suggest the capacity of intra-modal learning of regularities in the auditory modality and based on stimuli that share the same perceptual properties.

Emotional prosody in congenital amusia: Impaired and spared processes.

Congenital amusia is a lifelong deficit of music processing, in particular of pitch processing. Most research investigating this neurodevelopmental disorder has focused on music perception, but pitch also has a critical role for intentional and emotional prosody in speech. Two previous studies investigating amusics' emotional prosody recognition have shown either some deficit or no deficit (compared to controls). However, these previous studies have used only long sentence stimuli, which allow for limited control over acoustic content. Here, we tested amusic individuals for emotional prosody perception in sentences and vowels. For each type of material, participants performed an emotion categorization task, followed by intensity ratings of the recognized emotion. Compared to controls, amusic individuals had similar recognition of emotion in sentences, but poorer performance in vowels, especially when distinguishing sad and neutral stimuli. These lower performances in amusics were linked with difficulties in processing pitch and spectro-temporal parameters of the vowel stimuli. For emotion intensity, neither sentence nor vowel ratings differed between participant groups, suggesting preserved implicit processing of emotional prosody in amusia. These findings can be integrated into previous data showing preserved implicit processing of pitch and emotion in amusia alongside deficits in explicit recognition tasks. They are thus further supporting the hypothesis of impaired conscious analysis of pitch and timbre in this neurodevelopmental disorder.

Boosting syntax training with temporally regular musical primes in children with cochlear implants.

OBJECTIVES: Previous research has suggested the use of rhythmic structures (implemented in musical material) to improve linguistic structure processing (i.e., syntax processing), in particular for populations showing deficits in syntax and temporal processing (e.g., children with developmental language disorders). The present study proposes a long-term training program to improve syntax processing in children with cochlear implants, a population showing syntax processing deficits in perception and production. METHODS: The training program consisted of morphosyntactic training exercises (based on speech processing) that were primed by musical regular primes (8 sessions) or neutral baseline primes (environmental sounds) (8 sessions). A crossover design was used to train 10 deaf children with cochlear implants. Performance in grammatical processing, non-word repetition, attention and memory was assessed before and after training. RESULTS: Training increased performance for syntax comprehension after both prime types but for grammaticality judgements and non-word repetition only when musical primes were used during training. For the far-transfer tests, some effects were also observed for attention tasks, especially if fast and precise sequential analysis (sequencing) was required, but not for memory tasks. CONCLUSIONS: The findings extend the previously observed beneficial short-term effects of regular musical primes in the laboratory to long-term training effects. Results suggest that the musical primes improved the processing of the syntactic training material, thus enhancing the training effects on grammatical processing as well as phonological processing and sequencing of speech signals. The findings can be interpreted within the dynamic attending theory (postulating the modulation of attention over time) and associated oscillatory brain activity. Furthermore, the findings encourage the use of rhythmic structures (even in non-verbal materials) in language training programs and outline perspectives for rehabilitation.

Effects of preference and sensory modality on behavioural reaction in patients with disorders of consciousness.

BACKGROUND: Reliable evaluation of patients with unresponsive wakefulness syndrome (UWS) or in a minimally conscious state (MCS) remains a major challenge. It has been suggested that the expression of residual cerebral function could be improved by allowing patients to listen to their favourite music. However, the potential effect of music on behavioural responsiveness, as well as the effect of preferred stimuli in other sensory modalities (e.g. olfaction), remain poorly understood. OBJECTIVE: The aim of our study was to investigate the effect of sensory modality (auditory versus olfactory) and preference (preferred versus neutral) of the test stimuli on patients' subsequent performance on the Coma Recovery Scale-Revised (CRS-R). RESEARCH DESIGN: Within-subject design because of inter-individual differences between patients. METHODS AND PROCEDURES: We studied four items from the CRS-R (visual pursuit using a mirror, auditory localization of the own name and two movements to command) in 13 patients (7 MCS; 6 UWS). MAIN OUTCOMES AND RESULTS: Auditory stimuli triggered higher responsiveness compared to olfactory stimuli, and preferred stimuli were followed by higher scores than did neutral stimuli. CONCLUSIONS: Findings suggest that preferred auditory stimuli at the bedside contribute to the expression of residual function and could improve the diagnostic assessment.

Implicit learning of between-group intervals in auditory temporal structures.

Implicit learning of temporal structure has primarily been reported when events within a sequence (e.g., visual-spatial locations, tones) are systematically ordered and correlated with the temporal structure. An auditory serial reaction time task was used to investigate implicit learning of temporal intervals between pseudorandomly ordered syllables. Over exposure, participants identified syllables presented in sequences with weakly metrical temporal structures. In a test block, the temporal structure differed from exposure only in the duration of the interonset intervals (IOIs) between groups. It was hypothesized that reaction time (RT) to syllables following between-group IOIs would decrease with exposure and increase at test. In Experiments 1 and 2, the sequences presented over exposure and test were counterbalanced across participants (Pattern 1 and Pattern 2 conditions). An RT increase at test to syllables following between-group IOIs was only evident in the condition that presented an exposure structure with a slightly stronger meter (Pattern 1 condition). The Pattern 1 condition also elicited a global expectancy effect: Test block RT slowed to earlier-than-expected syllables (i.e., syllables shifted to an earlier beat) but not to later-than-expected syllables. Learning of between-group IOIs and the global expectancy effect extended to the Pattern 2 condition when meter was strengthened with an external pulse (Experiment 2). Experiment 3 further demonstrated implicit learning of a new weakly metrical structure with only earlier-than-expected violations at test. Overall findings demonstrate learning of weakly metrical rhythms without correlated event structures (i.e., sequential syllable orders). They further suggest the presence of a global expectancy effect mediated by metrical strength.

The role of auditory feedback in music-supported stroke rehabilitation: A single-blinded randomised controlled intervention.

PURPOSE: Learning to play musical instruments such as piano was previously shown to benefit post-stroke motor rehabilitation. Previous work hypothesised that the mechanism of this rehabilitation is that patients use auditory feedback to correct their movements and therefore show motor learning. We tested this hypothesis by manipulating the auditory feedback timing in a way that should disrupt such error-based learning. METHODS: We contrasted a patient group undergoing music-supported therapy on a piano that emits sounds immediately (as in previous studies) with a group whose sounds are presented after a jittered delay. The delay was not noticeable to patients. Thirty-four patients in early stroke rehabilitation with moderate motor impairment and no previous musical background learned to play the piano using simple finger exercises and familiar children's songs. RESULTS: Rehabilitation outcome was not impaired in the jitter group relative to the normal group. Conversely, some clinical tests suggests the jitter group outperformed the normal group. CONCLUSIONS: Auditory feedback-based motor learning is not the beneficial mechanism of music-supported therapy. Immediate auditory feedback therapy may be suboptimal. Jittered delay may increase efficacy of the proposed therapy and allow patients to fully benefit from motivational factors of music training. Our study shows a novel way to test hypotheses concerning music training in a single-blinded way, which is an important improvement over existing unblinded tests of music interventions.

Congenital amusias.

In contrast to the sophisticated music processing reported in the general population, individuals with congenital amusia show deficits in music perception and production. Congenital amusia occurs without brain damage, sensory or cognitive deficits, and has been suggested as a lifelong deficit with genetic origin. Even though recognized for a long time, this disorder has been systematically studied only relatively recently for its behavioral and neural correlates. The currently most investigated hypothesis about the underlying deficits concerns the pitch dimension, notably with impaired pitch discrimination and memory. Anatomic and functional investigations of pitch processing revealed that the amusic brain presents abnormalities in the auditory and inferior frontal cortices, associated with decreased connectivity between these structures. The deficit also impairs processing of pitch in speech material and processing of the time dimension in music for some of the amusic individuals, but does not seem to affect spatial processing. Some studies suggest at least partial dissociation in the disorder between perception and production. Recent studies revealed spared implicit pitch perception in congenital amusia, supporting the power of implicit cognition in the music domain. Current challenges consist in defining different subtypes of congenital amusia as well as developing rehabilitation programs for this "musical handicap."

[Beneficial effect of preferred music on cognitive functions in minimally conscious state patients]. / Effets bénéfiques de la musique préférée sur les capacités cognitives des patients en état de conscience minimale.

Several studies have shown that music can boost cognitive functions in normal and brain-damaged subjects. A few studies have suggested a beneficial effect of music in patients with a disorder of consciousness but it is difficult to conclude since they did not use quantified measures and a control condition/group. The aim of the present study was to compare the effect of music to that of a continuous sound on the relational behavior of patients in a minimally conscious state (MCS). Behavioral responses of six MCS patients were evaluated using items from the Coma Recovery Scale-Revised. Weekly evaluation sessions were carried out, over four weeks, under two conditions: following the presentation of either the patient's preferred music, or following a continuous sound (control condition). Qualitative and quantitative analyses showed that twelve of the eighteen sessions (66.6%) showed a better result for the music condition than for the control condition. This new protocol suggests that preferred music has a beneficial effect on the cognitive abilities of MCS patients. The results further suggest that cerebral plasticity may be enhanced in autobiographical (emotional and familiar) contexts. These findings should now be further extended with an increased number of patients to further validate the hypothesis of the beneficial effect of music on cognitive recovery.

[Acquired amusia and musical anhedonia]. / Amusie acquise et anhédonie musicale.

Amusia is defined as an auditory agnosia, specifically related to music, resulting from a cerebral lesion or being of congenital origin. Amusia is rarely associated to musical anhedonia. We report the case of a 43-year-old patient who suffered in January 2012 from a right ischemic lesion affecting the superior temporal cortex, in particular lateral Heschl Gyrus and the posterior part of the Superior Temporal Gyrus (Brodmann areas 21 and 22). Neuropsychological tests revealed an amusia combined to musical anhedonia. The specificity of this case is based on the combination of both syndromes highlighting the relation between neural networks involved in the processing of musical information in both its perceptual and emotional components.

The role of expectation in music: from the score to emotions and the brain.

Like discourse, music is a dynamic process that occurs over time. Listeners usually expect some events or structures of events to occur in the prolongation of a given context. Part of the musical emotional experience would depend upon how composers (improvisers) fulfill these expectancies. Musical expectations are a core phenomenon of music cognition, and the present article provides an overview of its foundation in the score as well as in listeners' behavior and brain, and how it can be simulated by artificial neural networks. We highlight parallels to language processing and include the attentional and emotional dimensions of musical expectations. Studying musical expectations is thus valuable not only for our understanding of music perception and production but also for more general brain functioning. Some open and challenging issues are summarized in this article. WIREs Cogn Sci 2014, 5:105-113. doi: 10.1002/wcs.1262 CONFLICT OF INTEREST: The authors have no conflict of interest to declare. For further resources related to this article, please visit the WIREs website.

Regularity of unit length boosts statistical learning in verbal and nonverbal artificial languages.

Humans have remarkable statistical learning abilities for verbal speech-like materials and for nonverbal music-like materials. Statistical learning has been shown with artificial languages (AL) that consist of the concatenation of nonsense word-like units into a continuous stream. These ALs contain no cues to unit boundaries other than the transitional probabilities between events, which are high within a unit and low between units. Most AL studies have used units of regular lengths. In the present study, the ALs were based on the same statistical structures but differed in unit length regularity (i.e., whether they were made out of units of regular vs. irregular lengths) and in materials (i.e., syllables vs. musical timbres), to allow us to investigate the influence of unit length regularity on domain-general statistical learning. In addition to better performance for verbal than for nonverbal materials, the findings revealed an effect of unit length regularity, with better performance for languages with regular- (vs. irregular-) length units. This unit length regularity effect suggests the influence of dynamic attentional processes (as proposed by the dynamic attending theory; Large & Jones (Psychological Review 106: 119-159, 1999)) on domain-general statistical learning.

Shared structural and temporal integration resources for music and arithmetic processing.

While previous research has investigated the relationship either between language and music processing or between language and arithmetic processing, the present study investigated the relationship between music and arithmetic processing. Rule-governed number series, with the final number being a correct or incorrect series ending, were visually presented in synchrony with musical sequences, with the final chord functioning as the expected tonic or the less-expected subdominant chord (i.e., tonal function manipulation). Participants were asked to judge the correctness of the final number as quickly and accurately as possible. The results revealed an interaction between the processing of series ending and the processing of the task-irrelevant chords' tonal function, thus suggesting that music and arithmetic processing share cognitive resources. These findings are discussed in terms of general temporal and structural integration resources for linguistic and non-linguistic rule-governed sequences.

[Minimally invasive hip arthroplasty - what must be spared?]. / Minimal-invasive Hüftendoprothetik - was muss geschont werden?

The classical surgical approach to the hip joint has been modified in recent years. The development of minimally invasive surgical techniques promised a particularly gentle soft-tissue preparation with significant benefits in postoperative recovery and intraoperative blood loss for patients undergoing total hip arthroplasty (THA). Exact knowledge of the anatomy of the hip joint and the surrounding structures at risk are essential to avoid complications. Each of the main minimally invasive approaches for THA implicates very specific advantages and disadvantages. Knowing these factors, minimally invasive hip surgery can be performed in a soft tissue-friendly manner. The resulting advantages have to be checked for significant clinical evidence.

The antimicrobial peptide HBD-2 and the Toll-like receptors-2 and -4 are induced in synovial membranes in case of septic arthritis.

Septic arthritis is frequently observed especially in immune-compromised or chronically diseased patients and leads to functional impairment due to tissue destruction. Recently, production of antimicrobial peptides (AMP) was observed in articular cartilage after exposure to bacteria. This report examines the role of synoviocyte-derived AMPs in innate defense mechanisms of articular joints. Samples of healthy, low-grade synovialitis and septic synovial membranes were assessed for the expression of human beta-defensin-2 (HBD-2) and Toll-like receptor-2 and -4 (TLR) by immunohistochemistry and enzyme-linked immunosorbent assay (ELISA). A stable synoviocyte line (K4IM) was used for in vitro experiments and assayed for endogenous HBD-2 and TLR production after exposure to inflammatory cytokines or bacterial supernatants by reverse transcription polymerase chain reaction (RT-PCR), real-time RT-PCR, Western blot, ELISA, and dual luciferase assay. Healthy human synovial membranes and cultured synoviocytes are able to produce HBD-2 and TLR-1-5 at basal expression levels. Samples of bacteria-colonized synovial membranes produce higher levels of HBD-2 when compared with samples of healthy tissues. K4IM synoviocytes exposed to Staphylococcus aureus, Pseudomonas aeruginosa, or proinflammatory cytokines demonstrated a clear HBD-2 transcription and protein induction. TLR-2 and -4 are known to have a critical role in the recognition of gram-positive and gram-negative bacteria in epithelia and are induced in mesenchymal synoviocytes after bacterial exposure on transcription and on protein level. This report demonstrates an unappreciated role of synovial membranes: samples of septic synovial membranes and cultured synoviocytes exposed to bacteria produce increased amounts of the AMP HBD-2 and the bacteria recognition receptors TLR-2 and -4. The induction of anti-inflammatory pathways in infected synoviocytes suggests involvement in intra-articular defense mechanisms.

Tonal expectations influence pitch perception.

In this study, we investigated the influence of tonal relatedness on pitch perception in melodies. Tonal expectations for target tones were manipulated in melodic contexts while controlling sensory expectations, thus allowing us to assess specifically the influence oftonal expectations on pitch perception. Three experimentsprovided converging evidence that tonal relatedness modulates pitch perception in nonmusician listeners. Experiment 1 showed, with a rating task, the influence of the tonal relatedness of a target tone on listeners' judgments of tuning/mistuning. Experiment 2 showed, with a priming task, that pitch processing of in-tune tones was faster for tonally related targets than for less related targets. Experiment 3 showed, with a comparison task, that discrimination performance for small mistunings was better when the to-be-compared tones were tonally related to the melodic context. Findings are discussed in relation to psychoacoustic research on contextual pitch perception and to studies showing facilitation of early processing steps via knowledge- and attention-related processes.

The tonal function of a task-irrelevant chord modulates speed of visual processing.

Harmonic priming studies have provided evidence that musical expectations influence sung phoneme monitoring, with facilitated processing for phonemes sung on tonally related (expected) chords in comparison to less-related (less-expected) chords [Bigand, Tillmann, Poulin, D'Adamo, and Madurell (2001). The effect of harmonic context on phoneme monitoring in vocal music. Cognition, 81, B11-B20]. This tonal relatedness effect has suggested two interpretations: (a) processing of music and language interact at some level of processing; and (b) tonal functions of chords influence task performance via listeners' attention. Our study investigated these hypotheses by exploring whether the effect of tonal relatedness extends to the processing of visually presented syllables (Experiments 1 and 2) and geometric forms (Experiments 3 and 4). For Experiments 1-4, visual target identification was faster when the musical background fulfilled listeners' expectations (i.e., a related chord was played simultaneously). In Experiment 4, the addition of a baseline condition (i.e., without an established tonal center) further showed that the observed difference was due to a facilitation linked to the related chord and not to an inhibition or disruption caused by the less-related chord. This outcome suggests the influence of musical structures on attentional mechanisms and that these mechanisms are shared between auditory and visual modalities. The implications for research investigating neural correlates shared by music and language processing are discussed.

Effects of pleiotrophin, a heparin-binding growth factor, on human primary and immortalized chondrocytes.

OBJECTIVE: Pleiotrophin (PTN) is a secreted heparin-binding peptide expressed in mesodermal and neuroectodermal cells during development, but rarely in adult tissues. In fetal and juvenile, but not in mature cartilage, PTN is abundant. Furthermore, PTN is re-expressed in chondrocytes in early stages of osteoarthritis (OA). Since little is known about the functions of PTN in cartilage, we investigated the occurrence of PTN receptors in human articular cartilage in situ and PTN effects on human primary and immortalized chondrocytes in vitro. METHODS: Receptor expression and regulation was monitored by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry. PTN effects and signal transduction were studied by electrophoretic mobility shift, Boyden chamber cell migration and proliferation assays, effects on gene expression by real time RT-PCR and that on nitric oxide (NO) by the Griess reaction. RESULTS: Of the putative PTN signaling receptors, immortalized and primary chondrocytes (pc) expressed the anaplastic lymphoma kinase (ALK), less the receptor-type protein tyrosine phosphatase zeta/beta (PTPzeta). ALK expression was upregulated upon ligand exposure. PTN stimulation activated the AP-1 (activator protein-1) transcription factor and altered gene expression. Prolonged stimulation induced PTN mRNA expression slightly, reduced vascular endothelial growth factor (VEGF) mRNA as well as NO production. Whereas mRNA expression of matrix metalloproteinases (MMPs) MMP-1 and MMP-13 was reduced, their inhibitors TIMP-1 and TIMP-2 were induced. Furthermore, PTN stimulated chondrocyte migration and proliferation. CONCLUSIONS: These results show that PTN is an autocrine growth factor in cartilage. We suggest that PTN may be involved in the clustering and proliferation of chondrocytes observed in the early stages of OA.