Multidimensional scaling of emotional responses to music in patients with temporal lobe resection

Emotion topology: extracting fundamental components of emotions from text using word embeddings

This exploratory study examined the potential of word embeddings, an automated numerical representation of written text, as a novel method for emotion decomposition analysis. Drawing from a substantial dataset scraped from a Social Media site, we constructed emotion vectors to extract the dimensions of emotions, as annotated by the readers of the texts, directly from human language. Our findings demonstrated that word embeddings yield emotional components akin to those found in previous literature, offering an alternative perspective not bounded by theoretical presuppositions, as well as showing that the dimensional structure of emotions is reflected in the semantic structure of their text-based expressions. Our study highlights word embeddings as a promising tool for uncovering the nuances of human emotions and comments on the potential of this approach for other psychological domains, providing a basis for future studies. The exploratory nature of this research paves the way for further development and refinement of this method, promising to enrich our understanding of emotional constructs and psychological phenomena in a more ecologically valid and data-driven manner.

Neural manifold analysis of brain circuit dynamics in health and disease

Recent developments in experimental neuroscience make it possible to simultaneously record the activity of thousands of neurons. However, the development of analysis approaches for such large-scale neural recordings have been slower than those applicable to single-cell experiments. One approach that has gained recent popularity is neural manifold learning. This approach takes advantage of the fact that often, even though neural datasets may be very high dimensional, the dynamics of neural activity tends to traverse a much lower-dimensional space. The topological structures formed by these low-dimensional neural subspaces are referred to as "neural manifolds", and may potentially provide insight linking neural circuit dynamics with cognitive function and behavioral performance. In this paper we review a number of linear and non-linear approaches to neural manifold learning, including principal component analysis (PCA), multi-dimensional scaling (MDS), Isomap, locally linear embedding (LLE), Laplacian eigenmaps (LEM), t-SNE, and uniform manifold approximation and projection (UMAP). We outline these methods under a common mathematical nomenclature, and compare their advantages and disadvantages with respect to their use for neural data analysis. We apply them to a number of datasets from published literature, comparing the manifolds that result from their application to hippocampal place cells, motor cortical neurons during a reaching task, and prefrontal cortical neurons during a multi-behavior task. We find that in many circumstances linear algorithms produce similar results to non-linear methods, although in particular cases where the behavioral complexity is greater, non-linear methods tend to find lower-dimensional manifolds, at the possible expense of interpretability. We demonstrate that these methods are applicable to the study of neurological disorders through simulation of a mouse model of Alzheimer's Disease, and speculate that neural manifold analysis may help us to understand the circuit-level consequences of molecular and cellular neuropathology.

The hearing hippocampus

The hippocampus has a well-established role in spatial and episodic memory but a broader function has been proposed including aspects of perception and relational processing. Neural bases of sound analysis have been described in the pathway to auditory cortex, but wider networks supporting auditory cognition are still being established. We review what is known about the role of the hippocampus in processing auditory information, and how the hippocampus itself is shaped by sound. In examining imaging, recording, and lesion studies in species from rodents to humans, we uncover a hierarchy of hippocampal responses to sound including during passive exposure, active listening, and the learning of associations between sounds and other stimuli. We describe how the hippocampus' connectivity and computational architecture allow it to track and manipulate auditory information - whether in the form of speech, music, or environmental, emotional, or phantom sounds. Functional and structural correlates of auditory experience are also identified. The extent of auditory-hippocampal interactions is consistent with the view that the hippocampus makes broad contributions to perception and cognition, beyond spatial and episodic memory. More deeply understanding these interactions may unlock applications including entraining hippocampal rhythms to support cognition, and intervening in links between hearing loss and dementia.

Music interventions for acquired brain injury

BACKGROUND

Acquired brain injury (ABI) can result in impairments in motor function, language, cognition, and sensory processing, and in emotional disturbances, which can severely reduce a survivor's quality of life. Music interventions have been used in rehabilitation to stimulate brain functions involved in movement, cognition, speech, emotions, and sensory perceptions. An update of the systematic review published in 2010 was needed to gauge the efficacy of music interventions in rehabilitation for people with ABI.

OBJECTIVES

To assess the effects of music interventions for functional outcomes in people with ABI. We expanded the criteria of our existing review to: 1) examine the efficacy of music interventions in addressing recovery in people with ABI including gait, upper extremity function, communication, mood and emotions, cognitive functioning, social skills, pain, behavioural outcomes, activities of daily living, and adverse events; 2) compare the efficacy of music interventions and standard care with a) standard care alone, b) standard care and placebo treatments, or c) standard care and other therapies; 3) compare the efficacy of different types of music interventions (music therapy delivered by trained music therapists versus music interventions delivered by other professionals).

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (January 2016), the Cochrane Central Register of Controlled Trials (CENTRAL) (2015, Issue 6), MEDLINE (1946 to June 2015), Embase (1980 to June 2015), CINAHL (1982 to June 2015), PsycINFO (1806 to June 2015), LILACS (1982 to January 2016), and AMED (1985 to June 2015). We handsearched music therapy journals and conference proceedings, searched dissertation and specialist music databases, trials and research registers, reference lists, and contacted relevant experts and music therapy associations to identify unpublished research. We imposed no language restriction. We performed the original search in 2009.

SELECTION CRITERIA

We included all randomised controlled trials and controlled clinical trials that compared music interventions and standard care with standard care alone or combined with other therapies. We examined studies that included people older than 16 years of age who had ABI of a non-degenerative nature and were participating in treatment programmes offered in hospital, outpatient, or community settings. We included studies in any language, published and unpublished.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias of the included studies. We contacted trial researchers to obtain missing data or for additional information when necessary. Where possible, we presented results for continuous outcomes in meta-analyses using mean differences (MDs) and standardised mean differences (SMDs). We used post-test scores. In cases of significant baseline difference, we used change scores. We conducted a sensitivity analysis to assess the impact of the randomisation method.

MAIN RESULTS

We identified 22 new studies for this update. The evidence for this update is based on 29 trials involving 775 participants. A music intervention known as rhythmic auditory stimulation may be beneficial for improving the following gait parameters after stroke. We found a reported increase in gait velocity of 11.34 metres per minute (95% confidence interval (CI) 8.40 to 14.28; 9 trials; 268 participants; P < 0.00001; moderate-quality evidence). Stride length of the affected side may also benefit, with a reported average of 0.12 metres more (95% CI 0.04 to 0.20; 5 trials; 129 participants; P = 0.003; moderate-quality evidence). We found a reported average improvement for general gait of 7.67 units on the Dynamic Gait Index (95% CI 5.67 to 9.67; 2 trials; 48 participants; P < 0.00001). There may also be an improvement in gait cadence, with a reported average increase of 10.77 steps per minute (95% CI 4.36 to 17.18; 7 trials; 223 participants; P = 0.001; low-quality evidence).Music interventions may be beneficial for improving the timing of upper extremity function after stroke as scored by a reduction of 1.08 seconds on the Wolf Motor Function Test (95% CI -1.69 to -0.47; 2 trials; 122 participants; very low-quality evidence).Music interventions may be beneficial for communication outcomes in people with aphasia following stroke. Overall, communication improved by 0.75 standard deviations in the intervention group, a moderate effect (95% CI 0.11 to 1.39; 3 trials; 67 participants; P = 0.02; very low-quality evidence). Naming was reported as improving by 9.79 units on the Aachen Aphasia Test (95% CI 1.37 to 18.21; 2 trials; 35 participants; P = 0.02). Music interventions may have a beneficial effect on speech repetition, reported as an average increase of 8.90 score on the Aachen Aphasia Test (95% CI 3.25 to 14.55; 2 trials; 35 participants; P = 0.002).There may be an improvement in quality of life following stroke using rhythmic auditory stimulation, reported at 0.89 standard deviations improvement on the Stroke Specific Quality of Life Scale, which is considered to be a large effect (95% CI 0.32 to 1.46; 2 trials; 53 participants; P = 0.002; low-quality evidence). We found no strong evidence for effects on memory and attention. Data were insufficient to examine the effect of music interventions on other outcomes.The majority of studies included in this review update presented a high risk of bias, therefore the quality of the evidence is low.

AUTHORS' CONCLUSIONS

Music interventions may be beneficial for gait, the timing of upper extremity function, communication outcomes, and quality of life after stroke. These results are encouraging, but more high-quality randomised controlled trials are needed on all outcomes before recommendations can be made for clinical practice.

Emotional memory for musical excerpts in young and older adults

The emotions evoked by music can enhance recognition of excerpts. It has been suggested that memory is better for high than for low arousing music (Eschrich et al., 2005; Samson et al., 2009), but it remains unclear whether positively (Eschrich et al., 2008) or negatively valenced music (Aubé et al., 2013; Vieillard and Gilet, 2013) may be better recognized. Moreover, we still know very little about the influence of age on emotional memory for music. To address these issues, we tested emotional memory for music in young and older adults using musical excerpts varying in terms of arousal and valence. Participants completed immediate and 24 h delayed recognition tests. We predicted highly arousing excerpts to be better recognized by both groups in immediate recognition. We hypothesized that arousal may compensate consolidation deficits in aging, thus showing more prominent benefit of high over low arousing stimuli in older than younger adults on delayed recognition. We also hypothesized worst retention of negative excerpts for the older group, resulting in a recognition benefit for positive over negative excerpts specific to older adults. Our results suggest that although older adults had worse recognition than young adults overall, effects of emotion on memory do not seem to be modified by aging. Results on immediate recognition suggest that recognition of low arousing excerpts can be affected by valence, with better memory for positive relative to negative low arousing music. However, 24 h delayed recognition results demonstrate effects of emotion on memory consolidation regardless of age, with a recognition benefit for high arousal and for negatively valenced music. The present study highlights the role of emotion on memory consolidation. Findings are examined in light of the literature on emotional memory for music and for other stimuli. We finally discuss the implication of the present results for potential music interventions in aging and dementia.

Acquired amusia

Recent developments in the cognitive neuroscience of music suggest that a further review of the topic of amusia is timely. In this chapter, we first consider previous taxonomies of amusia and propose a fresh framework for understanding the amusias, essentially as disorders of cognitive information processing. We critically review current cognitive and neuroanatomic findings in the published literature on amusia. We assess the extent to which the clinical and neuropsychologic evidence in amusia can be reconciled; both with the information-processing framework we propose, and with the picture of the brain organization of music and language processing emerging from cognitive neuroscience and functional neuroimaging studies. The balance of evidence suggests that the amusias can be understood as disorders of musical object cognition targeting separable levels of an information-processing hierarchy and underpinned by specific brain network dysfunction. The neuroanatomic associations of the amusias show substantial overlap with brain networks that process speech; however, this convergence leaves scope for separable brain mechanisms based on altered connectivity and dynamics across culprit networks. The study of the amusias contributes to an increasingly complex picture of the musical brain that transcends any simple dichotomy between music and speech or other complex sounds.

The role of the medial temporal limbic system in processing emotions in voice and music

Subcortical brain structures of the limbic system, such as the amygdala, are thought to decode the emotional value of sensory information. Recent neuroimaging studies, as well as lesion studies in patients, have shown that the amygdala is sensitive to emotions in voice and music. Similarly, the hippocampus, another part of the temporal limbic system (TLS), is responsive to vocal and musical emotions, but its specific roles in emotional processing from music and especially from voices have been largely neglected. Here we review recent research on vocal and musical emotions, and outline commonalities and differences in the neural processing of emotions in the TLS in terms of emotional valence, emotional intensity and arousal, as well as in terms of acoustic and structural features of voices and music. We summarize the findings in a neural framework including several subcortical and cortical functional pathways between the auditory system and the TLS. This framework proposes that some vocal expressions might already receive a fast emotional evaluation via a subcortical pathway to the amygdala, whereas cortical pathways to the TLS are thought to be equally used for vocal and musical emotions. While the amygdala might be specifically involved in a coarse decoding of the emotional value of voices and music, the hippocampus might process more complex vocal and musical emotions, and might have an important role especially for the decoding of musical emotions by providing memory-based and contextual associations.

Seeing through the eyes of anxious individuals: an investigation of anxiety-related interpretations of emotional expressions

The interpretation of emotional states is necessary for successful social communication. Often individuals interpret emotional expressions intuitively and without full cognitive awareness. The aim of the present study was to test whether anxiety would influence affect interpretation in the manner suggested by interpretation bias-the tendency to interpret ambiguous cues in a threatening way. Interpretation of social cues was assessed with the similarity rating task (simtask) in two studies (n1 = 116, n2 = 76). The similarity ratings were analysed with a multidimensional scaling (MDS) approach, and the effects of anxiety on the interpretation of emotional expressions were analysed with multilevel modelling. The results of both studies showed evidence for an anxiety-related interpretation bias. High-anxious individuals tended to interpret milder threats as more negative than low-anxious individuals did. The consequences for anxiety research are discussed.

Current Emotion Research in Behavioral Neuroscience: The Role(s) of the Amygdala

Substantial advances in our understanding of the neural bases of emotional processing have been made over the past decades. Overall, studies in humans and other animals highlight the key role of the amygdala in the detection and evaluation of stimuli with affective value. Nonetheless, contradictory findings have been reported, especially in terms of the exact role of this structure in the processing of different emotions, giving rise to different neural models of emotion. For instance, although the amygdala has traditionally been considered as exclusively involved in fear (and possibly anger), more recent work suggests that it may be important for processing other types of emotions, and even nonemotional information. A review of the main findings in this field is presented here, together with some of the hypotheses that have been put forward to interpret this literature and explain its inconsistencies.