Preliminary Evidence for Global Properties in Human Listeners During Natural Auditory Scene Perception

Theories of auditory and visual scene analysis suggest the perception of scenes relies on the identification and segregation of objects within it, resembling a detail-oriented processing style. However, a more global process may occur while analyzing scenes, which has been evidenced in the visual domain. It is our understanding that a similar line of research has not been explored in the auditory domain; therefore, we evaluated the contributions of high-level global and low-level acoustic information to auditory scene perception. An additional aim was to increase the field's ecological validity by using and making available a new collection of high-quality auditory scenes. Participants rated scenes on 8 global properties (e.g., open vs. enclosed) and an acoustic analysis evaluated which low-level features predicted the ratings. We submitted the acoustic measures and average ratings of the global properties to separate exploratory factor analyses (EFAs). The EFA of the acoustic measures revealed a seven-factor structure explaining 57% of the variance in the data, while the EFA of the global property measures revealed a two-factor structure explaining 64% of the variance in the data. Regression analyses revealed each global property was predicted by at least one acoustic variable (R2 = 0.33-0.87). These findings were extended using deep neural network models where we examined correlations between human ratings of global properties and deep embeddings of two computational models: an object-based model and a scene-based model. The results support that participants' ratings are more strongly explained by a global analysis of the scene setting, though the relationship between scene perception and auditory perception is multifaceted, with differing correlation patterns evident between the two models. Taken together, our results provide evidence for the ability to perceive auditory scenes from a global perspective. Some of the acoustic measures predicted ratings of global scene perception, suggesting representations of auditory objects may be transformed through many stages of processing in the ventral auditory stream, similar to what has been proposed in the ventral visual stream. These findings and the open availability of our scene collection will make future studies on perception, attention, and memory for natural auditory scenes possible.

Meditation, Compassionate Love, and Mental Health in Later Life

PURPOSE

Understanding of the mechanisms by which meditation imparts beneficial effects on later-life mental health is limited. The current study assessed the role of compassionate love in mediating the relationship between meditation and mental health in later life.

METHOD

Using data from a nationwide web-based survey (N = 1,861), we examined the indirect effects of meditation on depressive symptoms and anxiety via compassionate love.

RESULTS

Participants who practiced meditation (compared to those who did not) had significantly higher feelings of being loved (b = 0.11, p < 0.05); those who experienced more love had lower depressive symptoms (b = -2.10, p < 0.001) and anxiety (b = -0.99, p < 0.001). Meditation also had significant indirect effects (via compassionate love) on depressive symptoms (b = -0.23, p < 0.05) and anxiety (b = -0.11, p < 0.05).

CONCLUSION

This study underscores the need for contemplative interventions that foster compassionate love to improve mental health in later life. [Journal of Gerontological Nursing, 50(3), 40-50.].

Neural alpha oscillations index context-driven perception of ambiguous vowel sequences

Perception of bistable stimuli is influenced by prior context. In some cases, the interpretation matches with how the preceding stimulus was perceived; in others, it tends to be the opposite of the previous stimulus percept. We measured high-density electroencephalography (EEG) while participants were presented with a sequence of vowels that varied in formant transition, promoting the perception of one or two auditory streams followed by an ambiguous bistable sequence. For the bistable sequence, participants were more likely to report hearing the opposite percept of the one heard immediately before. This auditory contrast effect coincided with changes in alpha power localized in the left angular gyrus and left sensorimotor and right sensorimotor/supramarginal areas. The latter correlated with participants' perception. These results suggest that the contrast effect for a bistable sequence of vowels may be related to neural adaptation in posterior auditory areas, which influences participants' perceptual construal level of ambiguous stimuli.

Acoustic and Semantic Processing of Auditory Scenes in Children with Autism Spectrum Disorders

PURPOSE

Processing real-world sounds requires acoustic and higher-order semantic information. We tested the theory that individuals with autism spectrum disorder (ASD) show enhanced processing of acoustic features and impaired processing of semantic information.

METHODS

We used a change deafness task that required detection of speech and non-speech auditory objects being replaced and a speech-in-noise task using spoken sentences that must be comprehended in the presence of background speech to examine the extent to which 7-15 year old children with ASD (n = 27) rely on acoustic and semantic information, compared to age-matched (n = 27) and IQ-matched (n = 27) groups of typically developing (TD) children. Within a larger group of 7-15 year old TD children (n = 105) we correlated IQ, ASD symptoms, and the use of acoustic and semantic information.

RESULTS

Children with ASD performed worse overall at the change deafness task relative to the age-matched TD controls, but they did not differ from IQ-matched controls. All groups utilized acoustic and semantic information similarly and displayed an attentional bias towards changes that involved the human voice. Similarly, for the speech-in-noise task, age-matched-but not IQ-matched-TD controls performed better overall than the ASD group. However, all groups used semantic context to a similar degree. Among TD children, neither IQ nor the presence of ASD symptoms predict the use of acoustic or semantic information.

CONCLUSION

Children with and without ASD used acoustic and semantic information similarly during auditory change deafness and speech-in-noise tasks.

The Primacy of Compassionate Love: Loneliness and Psychological Well-Being in Later Life

Despite emerging research on compassionate love's positive influence on later-life psychological well-being, investigations on the mediating processes accountable for such effects are scarce. Using data from a nationwide web-based survey (N = 1,861), we performed a mediation analysis to assess the role of loneliness in explaining the impact of compassionate love on psychological well-being. Even after controlling for emotional support, our model estimates suggest that older adults who felt loved had significantly lower levels of loneliness (β = -0.84, p < 0.001), significantly fewer depressive symptoms (β = -0.86, p < 0.001), and lower anxiety (β = -0.25, p > 0.05). Loneliness completely mediated the effect of compassionate love on anxiety (β = -0.82, p < 0.001) and significantly mediated compassionate love's influence on depressive symptoms (β = -1.18, p < 0.001). Our findings underscore the need for interventions that increase compassionate love to reduce loneliness and improve psychological well-being in later life. [Journal of Gerontological Nursing, 49(4), 12-20.].

Sustained musical beat perception develops into late childhood and predicts phonological abilities

Sensitivity to auditory rhythmic structures in music and language is evident as early as infancy, but performance on beat perception tasks is often well below adult levels and improves gradually with age. While some research has suggested the ability to perceive musical beat develops early, even in infancy, it remains unclear whether adult-like perception of musical beat is present in children. The capacity to sustain an internal sense of the beat is critical for various rhythmic musical behaviors, yet very little is known about the development of this ability. In this study, 223 participants ranging in age from 4 to 23 years from the Las Vegas, Nevada, community completed a musical beat discrimination task, during which they first listened to a strongly metrical musical excerpt and then attempted to sustain their perception of the musical beat while listening to a repeated, beat-ambiguous rhythm for up to 14.4 s. They then indicated whether a drum probe matched or did not match the beat. Results suggested that the ability to identify the matching probe improved throughout middle childhood (8-9 years) and did not reach adult-like levels until adolescence (12-14 years). Furthermore, scores on the beat perception task were positively related to phonological processing, after accounting for age, short-term memory, and music and dance training. This study lends further support to the notion that children's capacity for beat perception is not fully developed until adolescence and suggests we should reconsider assumptions of musical beat mastery by infants and young children. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Adaptation in the sensory cortex drives bistable switching during auditory stream segregation

Current theories of perception emphasize the role of neural adaptation, inhibitory competition, and noise as key components that lead to switches in perception. Supporting evidence comes from neurophysiological findings of specific neural signatures in modality-specific and supramodal brain areas that appear to be critical to switches in perception. We used functional magnetic resonance imaging to study brain activity around the time of switches in perception while participants listened to a bistable auditory stream segregation stimulus, which can be heard as one integrated stream of tones or two segregated streams of tones. The auditory thalamus showed more activity around the time of a switch from segregated to integrated compared to time periods of stable perception of integrated; in contrast, the rostral anterior cingulate cortex and the inferior parietal lobule showed more activity around the time of a switch from integrated to segregated compared to time periods of stable perception of segregated streams, consistent with prior findings of asymmetries in brain activity depending on the switch direction. In sound-responsive areas in the auditory cortex, neural activity increased in strength preceding switches in perception and declined in strength over time following switches in perception. Such dynamics in the auditory cortex are consistent with the role of adaptation proposed by computational models of visual and auditory bistable switching, whereby the strength of neural activity decreases following a switch in perception, which eventually destabilizes the current percept enough to lead to a switch to an alternative percept.

Elements of musical and dance sophistication predict musical groove perception

Listening to groovy music is an enjoyable experience and a common human behavior in some cultures. Specifically, many listeners agree that songs they find to be more familiar and pleasurable are more likely to induce the experience of musical groove. While the pleasurable and dance-inducing effects of musical groove are omnipresent, we know less about how subjective feelings toward music, individual musical or dance experiences, or more objective musical perception abilities are correlated with the way we experience groove. Therefore, the present study aimed to evaluate how musical and dance sophistication relates to musical groove perception. One-hundred 24 participants completed an online study during which they rated 20 songs, considered high- or low-groove, and completed the Goldsmiths Musical Sophistication Index, the Goldsmiths Dance Sophistication Index, the Beat and Meter Sensitivity Task, and a modified short version of the Profile for Music Perception Skills. Our results reveal that measures of perceptual abilities, musical training, and social dancing predicted the difference in groove rating between high- and low-groove music. Overall, these findings support the notion that listeners' individual experiences and predispositions may shape their perception of musical groove, although other causal directions are also possible. This research helps elucidate the correlates and possible causes of musical groove perception in a wide range of listeners.

Auditory affective processing, musicality, and the development of misophonic reactions

Misophonia can be characterized both as a condition and as a negative affective experience. Misophonia is described as feeling irritation or disgust in response to hearing certain sounds, such as eating, drinking, gulping, and breathing. Although the earliest misophonic experiences are often described as occurring during childhood, relatively little is known about the developmental pathways that lead to individual variation in these experiences. This literature review discusses evidence of misophonic reactions during childhood and explores the possibility that early heightened sensitivities to both positive and negative sounds, such as to music, might indicate a vulnerability for misophonia and misophonic reactions. We will review when misophonia may develop, how it is distinguished from other auditory conditions (e.g., hyperacusis, phonophobia, or tinnitus), and how it relates to developmental disorders (e.g., autism spectrum disorder or Williams syndrome). Finally, we explore the possibility that children with heightened musicality could be more likely to experience misophonic reactions and develop misophonia.

Going Beyond Rote Auditory Learning: Neural Patterns of Generalized Auditory Learning

The ability to generalize across specific experiences is vital for the recognition of new patterns, especially in speech perception considering acoustic-phonetic pattern variability. Indeed, behavioral research has demonstrated that listeners are able via a process of generalized learning to leverage their experiences of past words said by difficult-to-understand talker to improve their understanding for new words said by that talker. Here, we examine differences in neural responses to generalized versus rote learning in auditory cortical processing by training listeners to understand a novel synthetic talker. Using a pretest-posttest design with EEG, participants were trained using either (1) a large inventory of words where no words were repeated across the experiment (generalized learning) or (2) a small inventory of words where words were repeated (rote learning). Analysis of long-latency auditory evoked potentials at pretest and posttest revealed that rote and generalized learning both produced rapid changes in auditory processing, yet the nature of these changes differed. Generalized learning was marked by an amplitude reduction in the N1-P2 complex and by the presence of a late negativity wave in the auditory evoked potential following training; rote learning was marked only by temporally later scalp topography differences. The early N1-P2 change, found only for generalized learning, is consistent with an active processing account of speech perception, which proposes that the ability to rapidly adjust to the specific vocal characteristics of a new talker (for which rote learning is rare) relies on attentional mechanisms to selectively modify early auditory processing sensitivity.

Auditory superiority for perceiving the beat level but not measure level in music

Auditory perception of time is superior to visual perception, both for simple intervals and beat-based musical rhythms. To what extent does this auditory advantage characterize perception of different hierarchical levels of musical meter, and how is it related to lifelong experience with music? We paired musical excerpts with auditory and visual metronomes that matched or mismatched the musical meter at the beat level (faster) and measure level (slower) and obtained fit ratings from adults and children (5-10 years). Adults exhibited an auditory advantage in this task for the beat level, but not for the measure level. Children also displayed an auditory advantage that increased with age for the beat level. In both modalities, their overall sensitivity to beat increased with age, but they were not sensitive to measure-level matching at any age. More musical training was related to enhanced sensitivity in both auditory and visual modalities for measure-level matching in adults and beat-level matching in children. These findings provide evidence for auditory superiority of beat perception across development, and they suggest that beat and meter perception develop quite gradually and rely on lifelong acquisition of musical knowledge. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Steady state-evoked potentials of subjective beat perception in musical rhythms

Synchronization of movement to music is a seemingly universal human capacity that depends on sustained beat perception. Previous research has suggested that listener's conscious perception of the musical structure (e.g., beat and meter) might be reflected in neural responses that follow the frequency of the beat. However, the extent to which these neural responses directly reflect concurrent, listener-reported perception of musical beat versus stimulus-driven activity is understudied. We investigated whether steady state-evoked potentials (SSEPs), measured using electroencephalography (EEG), reflect conscious perception of beat by holding the stimulus constant while contextually manipulating listeners' perception and measuring perceptual responses on every trial. Listeners with minimal music training heard a musical excerpt that strongly supported one of two beat patterns (context phase), followed by a rhythm consistent with either beat pattern (ambiguous phase). During the final phase, listeners indicated whether or not a superimposed drum matched the perceived beat (probe phase). Participants were more likely to indicate that the probe matched the music when that probe matched the original context, suggesting an ability to maintain the beat percept through the ambiguous phase. Likewise, we observed that the spectral amplitude during the ambiguous phase was higher at frequencies that matched the beat of the preceding context. Exploratory analyses investigated whether EEG amplitude at the beat-related SSEPs (steady state-evoked potentials) predicted performance on the beat induction task on a single-trial basis, but were inconclusive. Our findings substantiate the claim that auditory SSEPs reflect conscious perception of musical beat and not just stimulus features.

Resetting of Auditory and Visual Segregation Occurs After Transient Stimuli of the Same Modality

In the presence of a continually changing sensory environment, maintaining stable but flexible awareness is paramount, and requires continual organization of information. Determining which stimulus features belong together, and which are separate is therefore one of the primary tasks of the sensory systems. Unknown is whether there is a global or sensory-specific mechanism that regulates the final perceptual outcome of this streaming process. To test the extent of modality independence in perceptual control, an auditory streaming experiment, and a visual moving-plaid experiment were performed. Both were designed to evoke alternating perception of an integrated or segregated percept. In both experiments, transient auditory and visual distractor stimuli were presented in separate blocks, such that the distractors did not overlap in frequency or space with the streaming or plaid stimuli, respectively, thus preventing peripheral interference. When a distractor was presented in the opposite modality as the bistable stimulus (visual distractors during auditory streaming or auditory distractors during visual streaming), the probability of percept switching was not significantly different than when no distractor was presented. Conversely, significant differences in switch probability were observed following within-modality distractors, but only when the pre-distractor percept was segregated. Due to the modality-specificity of the distractor-induced resetting, the results suggest that conscious perception is at least partially controlled by modality-specific processing. The fact that the distractors did not have peripheral overlap with the bistable stimuli indicates that the perceptual reset is due to interference at a locus in which stimuli of different frequencies and spatial locations are integrated.

#EEGManyLabs: Investigating the replicability of influential EEG experiments

There is growing awareness across the neuroscience community that the replicability of findings about the relationship between brain activity and cognitive phenomena can be improved by conducting studies with high statistical power that adhere to well-defined and standardised analysis pipelines. Inspired by recent efforts from the psychological sciences, and with the desire to examine some of the foundational findings using electroencephalography (EEG), we have launched #EEGManyLabs, a large-scale international collaborative replication effort. Since its discovery in the early 20th century, EEG has had a profound influence on our understanding of human cognition, but there is limited evidence on the replicability of some of the most highly cited discoveries. After a systematic search and selection process, we have identified 27 of the most influential and continually cited studies in the field. We plan to directly test the replicability of key findings from 20 of these studies in teams of at least three independent laboratories. The design and protocol of each replication effort will be submitted as a Registered Report and peer-reviewed prior to data collection. Prediction markets, open to all EEG researchers, will be used as a forecasting tool to examine which findings the community expects to replicate. This project will update our confidence in some of the most influential EEG findings and generate a large open access database that can be used to inform future research practices. Finally, through this international effort, we hope to create a cultural shift towards inclusive, high-powered multi-laboratory collaborations.

Hierarchical beat perception develops throughout childhood and adolescence and is enhanced in those with musical training

Most music is temporally organized within a metrical hierarchy, having nested periodic patterns that give rise to the experience of stronger (downbeat) and weaker (upbeat) events. Musical meter presumably makes it possible to dance, sing, and play instruments in synchrony with others. It is nevertheless unclear whether or not listeners perceive multiple levels of periodicity simultaneously, and if they do, when and how they learn to do this. We tested children, adolescents, and musically trained and untrained adults with a new meter perception task. We presented excerpts of human-performed music paired with metronomes that matched or mismatched the metrical structure of the music at 2 hierarchical levels (beat and measure), and asked listeners to provide a rating of fit of metronome and music. Fit ratings suggested that adults with and without musical training were sensitive to both levels of meter simultaneously, but ratings were more strongly influenced by beat-level than by measure-level synchrony. Sensitivity to two simultaneous levels of meter was not evident in children or adolescents. Sensitivity to the beat alone was apparent in the youngest children and increased with age, whereas sensitivity to the measure alone was not present in younger children (5- to 8-year-olds). These findings suggest a prolonged period of development and refinement of hierarchical beat perception and surprisingly weak overall ability to attend to 2 beat levels at the same time across all ages. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Ensemble modeling of auditory streaming reveals potential sources of bistability across the perceptual hierarchy

Perceptual bistability-the spontaneous, irregular fluctuation of perception between two interpretations of a stimulus-occurs when observing a large variety of ambiguous stimulus configurations. This phenomenon has the potential to serve as a tool for, among other things, understanding how function varies across individuals due to the large individual differences that manifest during perceptual bistability. Yet it remains difficult to interpret the functional processes at work, without knowing where bistability arises during perception. In this study we explore the hypothesis that bistability originates from multiple sources distributed across the perceptual hierarchy. We develop a hierarchical model of auditory processing comprised of three distinct levels: a Peripheral, tonotopic analysis, a Central analysis computing features found more centrally in the auditory system, and an Object analysis, where sounds are segmented into different streams. We model bistable perception within this system by applying adaptation, inhibition and noise into one or all of the three levels of the hierarchy. We evaluate a large ensemble of variations of this hierarchical model, where each model has a different configuration of adaptation, inhibition and noise. This approach avoids the assumption that a single configuration must be invoked to explain the data. Each model is evaluated based on its ability to replicate two hallmarks of bistability during auditory streaming: the selectivity of bistability to specific stimulus configurations, and the characteristic log-normal pattern of perceptual switches. Consistent with a distributed origin, a broad range of model parameters across this hierarchy lead to a plausible form of perceptual bistability.

Stimulus-based and task-based attention modulate auditory stream segregation context effects

Previous studies have shown that perceptual segregation increases after listening to longer tone sequences, an effect known as buildup. More recently, an effect of prior frequency separation (Δƒ) has been discovered: presenting tone sequences with a small Δƒ biases following sequences with an intermediate Δƒ to be segregated into two separate streams, whereas presenting context sequences with a large Δƒ biases following sequences to be integrated into one stream. Here we investigated how attention and task demands influenced these effects of prior stimuli by having participants perform one of three tasks during the context: making streaming judgments on the tone sequences, detecting amplitude modulation in the tones, and performing a visual task while ignoring the tones. Results from two experiments showed that although the effect of prior Δƒ was present across all conditions, the effect was reduced whenever streaming judgments were not made during the context. Experiment 2 showed that streaming was reduced during the beginning of a test sequence only when participants performed the visual task during the context. These experiments suggest that task-based and stimulus-based attention differentially affect distinct influences of prior stimuli, and are consistent with the contribution of distinct levels of processing that affect auditory segregation. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Change detection in complex auditory scenes is predicted by auditory memory, pitch perception, and years of musical training

Our world is a sonically busy place and we use both acoustic information and experience-based knowledge to make sense of the sounds arriving at our ears. The knowledge we gain through experience has the potential to shape what sounds are prioritized in a complex scene. There are many examples of how visual expertise influences how we perceive objects in visual scenes, but few studies examine how auditory expertise is associated with attentional biases toward familiar real-world sounds in complex scenes. In the current study, we investigated whether musical expertise is associated with the ability to detect changes to real-world sounds in complex auditory scenes, and whether any such benefit is specific to musical instrument sounds. We also examined whether change detection is better for human-generated sounds in general or only communicative human sounds. We found that musicians had less change deafness overall. All listeners were better at detecting human communicative sounds compared to human non-communicative sounds, but this benefit was driven by speech sounds and sounds that were vocally generated. Musical listening skill, speech-in-noise, and executive function abilities were used to predict rates of change deafness. Auditory memory, musical training, fine-grained pitch processing, and an interaction between training and pitch processing accounted for 45.8% of the variance in change deafness. To better understand perceptual and cognitive expertise, it may be more important to measure various auditory skills and relate them to each other, as opposed to comparing experts to non-experts.

Children use object-level category knowledge to detect changes in complex auditory scenes

Children interact with and learn about all types of sound sources, including dogs, bells, trains, and human beings. Although it is clear that knowledge of semantic categories for everyday sights and sounds develops during childhood, there are very few studies examining how children use this knowledge to make sense of auditory scenes. We used a change deafness paradigm and an object-encoding task to investigate how children (6, 8, and 10 years of age) and adults process auditory scenes composed of everyday sounds (e.g., human voices, animal calls, environmental sounds, and musical instruments). Results indicated that although change deafness was present and robust at all ages, listeners improved at detecting changes with age. All listeners were less sensitive to changes within the same semantic category than to small acoustic changes, suggesting that, regardless of age, listeners relied heavily on semantic category knowledge to detect changes. Furthermore, all listeners showed less change deafness when they correctly encoded change-relevant objects (i.e., when they remembered hearing the changing object during the task). Finally, we found that all listeners were better at encoding human voices and were more sensitive to detecting changes involving the human voice. Despite poorer overall performance compared with adults, children detect changes in complex auditory scenes much like adults, using high-level knowledge about auditory objects to guide processing, with special attention to the human voice. (PsycINFO Database Record

Recent advances in exploring the neural underpinnings of auditory scene perception

Studies of auditory scene analysis have traditionally relied on paradigms using artificial sounds-and conventional behavioral techniques-to elucidate how we perceptually segregate auditory objects or streams from each other. In the past few decades, however, there has been growing interest in uncovering the neural underpinnings of auditory segregation using human and animal neuroscience techniques, as well as computational modeling. This largely reflects the growth in the fields of cognitive neuroscience and computational neuroscience and has led to new theories of how the auditory system segregates sounds in complex arrays. The current review focuses on neural and computational studies of auditory scene perception published in the last few years. Following the progress that has been made in these studies, we describe (1) theoretical advances in our understanding of the most well-studied aspects of auditory scene perception, namely segregation of sequential patterns of sounds and concurrently presented sounds; (2) the diversification of topics and paradigms that have been investigated; and (3) how new neuroscience techniques (including invasive neurophysiology in awake humans, genotyping, and brain stimulation) have been used in this field.

Broad attention to multiple individual objects may facilitate change detection with complex auditory scenes

Attention and other processing constraints limit the perception of objects in complex scenes, which has been studied extensively in the visual sense. We used a change deafness paradigm to examine how attention to particular objects helps and hurts the ability to notice changes within complex auditory scenes. In a counterbalanced design, we examined how cueing attention to particular objects affected performance in an auditory change-detection task through the use of valid or invalid cues and trials without cues (Experiment 1). We further examined how successful encoding predicted change-detection performance using an object-encoding task and we addressed whether performing the object-encoding task along with the change-detection task affected performance overall (Experiment 2). Participants had more error for invalid compared to valid and uncued trials, but this effect was reduced in Experiment 2 compared to Experiment 1. When the object-encoding task was present, listeners who completed the uncued condition first had less overall error than those who completed the cued condition first. All participants showed less change deafness when they successfully encoded change-relevant compared to irrelevant objects during valid and uncued trials. However, only participants who completed the uncued condition first also showed this effect during invalid cue trials, suggesting a broader scope of attention. These findings provide converging evidence that attention to change-relevant objects is crucial for successful detection of acoustic changes and that encouraging broad attention to multiple objects is the best way to reduce change deafness. (PsycINFO Database Record

Sex differences in concordance rates between auditory event-related potentials and subjective sexual arousal

Much research indicates men show a greater concordance between subjective and genital sexual arousal than do women. We investigated the relationship between subjective sexual arousal and brain activation in men and women. Subjective sexual arousal and auditory N1 and P3b ERP amplitudes were measured while 38 participants viewed erotic and non-erotic films. Most notably, there was a significant correlation between N1 amplitude and sexual arousal in men; for women, there was a significant correlation between the P3b amplitude and sexual arousal. ERP amplitudes were inversely associated with reported arousal, suggesting that sexual arousal interferes with early tone processing for men, and with later tone processing for women. Lastly, for women, pornography/erotica consumption was negatively correlated with P3b amplitudes, suggesting that women who consume more pornography/erotica may also show greater attention to erotic films.

Concurrent sound segregation impairments in schizophrenia: The contribution of auditory-specific and general cognitive factors

The present study sought to test whether perceptual segregation of concurrently played sounds is impaired in schizophrenia (SZ), whether impairment in sound segregation predicts difficulties with a real-world speech-in-noise task, and whether auditory-specific or general cognitive processing accounts for sound segregation problems. Participants with SZ and healthy controls (HCs) performed a mistuned harmonic segregation task during recording of event-related potentials (ERPs). Participants also performed a brief speech-in-noise task. Participants with SZ showed deficits in the mistuned harmonic task and the speech-in-noise task, compared to HCs. No deficit in SZ was found in the ERP component related to mistuned harmonic segregation at around 150ms (the object-related negativity or ORN), but instead showed a deficit in processing at around 400ms (the P4 response). However, regression analyses showed that indexes of education level and general cognitive function were the best predictors of sound segregation difficulties, suggesting non-auditory specific causes of concurrent sound segregation problems in SZ.

Auditory processing deficits in bipolar disorder with and without a history of psychotic features

OBJECTIVES

Auditory perception deficits have been identified in schizophrenia (SZ) and linked to dysfunction in the auditory cortex. Given that psychotic symptoms, including auditory hallucinations, are also seen in bipolar disorder (BD), it may be that individuals with BD who also exhibit psychotic symptoms demonstrate a similar impairment in auditory perception.

METHODS

Fifty individuals with SZ, 30 individuals with bipolar I disorder with a history of psychosis (BD+), 28 individuals with bipolar I disorder with no history of psychotic features (BD-), and 29 normal controls (NC) were administered a tone discrimination task and an emotion recognition task.

RESULTS

Mixed-model analyses of covariance with planned comparisons indicated that individuals with BD+ performed at a level that was intermediate between those with BD- and those with SZ on the more difficult condition of the tone discrimination task and on the auditory condition of the emotion recognition task. There were no differences between the BD+ and BD- groups on the visual or auditory-visual affect recognition conditions. Regression analyses indicated that performance on the tone discrimination task predicted performance on all conditions of the emotion recognition task. Auditory hallucinations in BD+ were not related to performance on either task.

CONCLUSIONS

Our findings suggested that, although deficits in frequency discrimination and emotion recognition are more severe in SZ, these impairments extend to BD+. Although our results did not support the idea that auditory hallucinations may be related to these deficits, they indicated that basic auditory deficits may be a marker for psychosis, regardless of SZ or BD diagnosis.

How previous experience shapes perception in different sensory modalities

What has transpired immediately before has a strong influence on how sensory stimuli are processed and perceived. In particular, temporal context can have contrastive effects, repelling perception away from the interpretation of the context stimulus, and attractive effects (TCEs), whereby perception repeats upon successive presentations of the same stimulus. For decades, scientists have documented contrastive and attractive temporal context effects mostly with simple visual stimuli. But both types of effects also occur in other modalities, e.g., audition and touch, and for stimuli of varying complexity, raising the possibility that context effects reflect general computational principles of sensory systems. Neuroimaging shows that contrastive and attractive context effects arise from neural processes in different areas of the cerebral cortex, suggesting two separate operations with distinct functional roles. Bayesian models can provide a functional account of both context effects, whereby prior experience adjusts sensory systems to optimize perception of future stimuli.

How modality specific is processing of auditory and visual rhythms?

The present study used ERPs to test the extent to which temporal processing is modality specific or modality general. Participants were presented with auditory and visual temporal patterns that consisted of initial two- or three-event beginning patterns. This delineated a constant standard time interval, followed by a two-event ending pattern delineating a variable test interval. Participants judged whether they perceived the pattern as a whole to be speeding up or slowing down. The contingent negative variation (CNV), a negative potential reflecting temporal expectancy, showed a larger amplitude for the auditory modality compared to the visual modality but a high degree of similarity in scalp voltage patterns across modalities, suggesting that the CNV arises from modality-general processes. A late, memory-dependent positive component (P3) also showed similar patterns across modalities.

Evidence for high-level feature encoding and persistent memory during auditory stream segregation

A test sequence of alternating low-frequency (A) and high-frequency (B) tones in a repeating ". . . ABAB . . ." pattern is more likely to be heard as 2 segregated streams of tones when it is preceded by an isofrequency inducer sequence whose frequency matches either the A- or B-tone frequency (e.g., ". . . BBBB . . .") of the test, a phenomenon referred to as stream biasing. Low-level processes such as stimulus-selective adaptation of frequency-tuned neurons within early auditory processing stages have been thought by some to mediate stream biasing; however, the current study tested for the involvement of higher level processes. Inducers whose frequency matched neither the A- nor B-tone frequency (e.g., ". . . CCCC . . .") sometimes facilitated stream biasing. Stream biasing was also sensitive to complex features of the inducer sequence, namely whether the rhythmic pattern of the inducer matched the rhythm of the ABAB test. Stream biasing occurred even when an 8-s silent interval separated the inducer and test sequences, a time span longer than previously recognized (Beauvois & Meddis, 1997). These results suggest the involvement of persistent activation of high-level representations that affect perception.

Finding the music of speech: Musical knowledge influences pitch processing in speech

Few studies comparing music and language processing have adequately controlled for low-level acoustical differences, making it unclear whether differences in music and language processing arise from domain-specific knowledge, acoustic characteristics, or both. We controlled acoustic characteristics by using the speech-to-song illusion, which often results in a perceptual transformation to song after several repetitions of an utterance. Participants performed a same-different pitch discrimination task for the initial repetition (heard as speech) and the final repetition (heard as song). Better detection was observed for pitch changes that violated rather than conformed to Western musical scale structure, but only when utterances transformed to song, indicating that music-specific pitch representations were activated and influenced perception. This shows that music-specific processes can be activated when an utterance is heard as song, suggesting that the high-level status of a stimulus as either language or music can be behaviorally dissociated from low-level acoustic factors.

Everyday musical experience is sufficient to perceive the speech-to-song illusion

Speech and song are readily differentiated from each other in everyday communication, yet sometimes listeners who have formal music training will hear a spoken utterance transform from speech to song when it is repeated (Deutsch, Henthorn, & Lapidis, 2011). It remains unclear whether music training is required to perceive this illusory transformation or whether implicit knowledge of musical structure is sufficient. The current study replicates Deutsch et al.'s findings with musicians and demonstrates the generalizability of this auditory illusion to casual music listeners with no formal training. We confirm that the illusory transformation is disrupted when the pitch height of each repetition of the utterance is transposed, and we find that raising the pitch height has a different effect on listeners' ratings than does lowering it. Auditory illusions such as this may offer unique opportunities to compare domain-specific and domain-general processing in the brain while holding acoustic characteristics constant.

Effects of attention to and awareness of preceding context tones on auditory streaming

This study determined whether facilitation of auditory stream segregation could occur when facilitating context tones are accompanied by other sounds. Facilitation was measured as the likelihood of a repeated context tone that could match the low (A) or high (B) frequency of a repeating ABA test to increase the likelihood of hearing the test as segregated. We observed this type of facilitation when matching tones were alone, or with simultaneous bandpass noises or continuous speech, neither of which masked the tones. However, participants showed no streaming facilitation when a harmonic complex masked the context tones. Mistuning or desynchronizing the context tone relative to the rest of the complex did not facilitate streaming, despite the fact that the context tone was accessible to awareness and attention. Even presenting the context tone in a separate ear from the rest of the harmonic complex did not facilitate streaming, ruling out peripheral interference. Presenting the test as mistuned or desynchronized tones relative to complex tones eliminated the possibility that timbre changes from context to test interfered with facilitation resulting from the context. These results demonstrate the fragility of streaming facilitation and show that awareness of and attention to the context tones are not sufficient to overcome interference.

Evidence for stimulus-general impairments on auditory stream segregation tasks in schizophrenia

BACKGROUND

Auditory impairments in schizophrenia have been demonstrated previously, especially for tasks requiring precise encoding of frequency, although it is unclear the extent to which they have difficulty using pitch information and other cues to segregate sounds. We determined the extent to which those with schizophrenia have difficulty using pitch information and other auditory cues to segregate sounds that are presented sequentially.

METHODS

Ten participants with schizophrenia and nine healthy/normal control participants completed a battery of tasks that tested for the ability to perform sequential auditory stream segregation using pitch, amplitude modulation, or inter-aural phase difference as cues to segregation.

RESULTS

All three sequential segregation tasks showed reduced tendency for those with schizophrenia to perceive segregated sounds, compared to control participants.

CONCLUSIONS

These findings extend prior research by demonstrating a general impairment on sequential sound segregation tasks in schizophrenia, and not just on tasks that require precise encoding of frequency. Together, the pattern of results provide evidence that auditory impairments in schizophrenia result from selective abnormalities in neural circuits that carry out specific computations necessary for stream segregation, as opposed to an impairment in processing specific cues.

Auditory stream segregation impairments in schizophrenia

We used behavior and event-related potentials (ERPs) to examine auditory stream segregation in people with schizophrenia and control participants. During each trial, a context pattern was presented, consisting of low (A) and high (B) tones and silence (-) in a repeating ABA- pattern, with a frequency separation (Δf) of 3, 6, or 12 semitones. Next, a test ABA-pattern was presented that always had a 6-semitone Δf. Larger Δf during the context resulted in more perception of two streams and larger N1 and P2 ERPs, but less perception of two streams during the test pattern. These effects of Δf were smaller in schizophrenia. Individuals with schizophrenia also showed a reduced effect of prior perceptual judgments. Overall, the findings demonstrate that people with schizophrenia have abnormalities in segregating sounds. These abnormalities result from difficulties utilizing frequency cues in addition to reduced temporal context effects.

Pattern specificity in the effect of prior Δƒ on auditory stream segregation

During repeating sequences of low (A) and high (B) tones, perception of two separate streams ("streaming") increases with greater frequency separation (Δƒ) between the A and B tones; in contrast, a prior context with large Δƒ results in less streaming during a subsequent test pattern. The purpose of the present study was to investigate what aspects of the context pattern are necessary for this context effect to occur. Simply changing the B-tone frequency without an alternating A tone present was not sufficient to cause the effect of prior Δƒ, but rather a melodic change between A and B tones was necessary. We further investigated the extent to which the context and test patterns needed to have similar rhythms (xxx-xxx-) and melodies (up-down-flat-up-down), and found that a maximal prior-Δƒ effect occurred when the rhythmic patterns of the context and test were similar, regardless of the melodic structure. Thus, the effect of prior Δƒ on streaming depended on the presence of (1) at least one melodic change in the context, and (2) similar rhythmic patterns in the context and test.

Attention, awareness, and the perception of auditory scenes

Auditory perception and cognition entails both low-level and high-level processes, which are likely to interact with each other to create our rich conscious experience of soundscapes. Recent research that we review has revealed numerous influences of high-level factors, such as attention, intention, and prior experience, on conscious auditory perception. And recently, studies have shown that auditory scene analysis tasks can exhibit multistability in a manner very similar to ambiguous visual stimuli, presenting a unique opportunity to study neural correlates of auditory awareness and the extent to which mechanisms of perception are shared across sensory modalities. Research has also led to a growing number of techniques through which auditory perception can be manipulated and even completely suppressed. Such findings have important consequences for our understanding of the mechanisms of perception and also should allow scientists to precisely distinguish the influences of different higher-level influences.

Visual and auditory perceptual rivalry in migraine

INTRODUCTION

Recent evidence demonstrates that perceptual rivalry rate can be modulated by perturbation of the serotonergic system. Specifically, pharmacologically lowering the availability of serotonin results in slower rivalry rates. As it has been suggested that brain serotonin is low during the interictal phase of migraine, we hypothesized that perceptual rivalry rates would be reduced in individuals with migraine.

METHODS

Visual and auditory perceptual rivalry measures were obtained for a group of 30 participants with migraine (15 migraine with aura, 15 migraine without aura) and 20 non-headache control individuals.

RESULTS

Our experiments reveal fewer perceptual rivalry switches within both visual and auditory domains for our migraine without aura group, while the with-aura group performed similarly to non-headache controls. Dividing the data by headache frequency rather than headache subtype classification revealed fewer perceptual switches in those with more frequent headaches.

CONCLUSIONS

Our data provides further support for interictal differences in brain sensory reactivity in migraine, with the observed effects being in the same direction as those caused by pharmacologically reducing brain availability of serotonin in normal observers.

Listening strategy for auditory rhythms modulates neural correlates of expectancy and cognitive processing

A recently described auditory tempo perception paradigm revealed individual differences in perceived stimulus timing for identical stimulus sequences. The current study takes advantage of this paradigm by recording event-related potentials (ERPs) concurrent with task performance in order to reveal brain responses that reflect individual differences in timing strategy. No strategy-related differences were observed in sensory encoding of tones, as measured by the P1-N1-P2 complex. However, the contingent negative variation (CNV) leading up to the final tone of the sequence varied as a function of strategy, as did a parietal-maximum late positive component (P3b) that occurred following the final tone. These data suggest that temporal expectancy for and cognitive processing of the final tone of rhythmic sequences underlies differences in strategy during rhythm perception.

Biological markers of auditory gap detection in young, middle-aged, and older adults

The capability of processing rapid fluctuations in the temporal envelope of sound declines with age and this contributes to older adults' difficulties in understanding speech. Although, changes in central auditory processing during aging have been proposed as cause for communication deficits, an open question remains which stage of processing is mostly affected by age related changes. We investigated auditory temporal resolution in young, middle-aged, and older listeners with neuromagnetic evoked responses to gap stimuli with different leading marker and gap durations. Signal components specific for processing the physical details of sound stimuli as well as the auditory objects as a whole were derived from the evoked activity and served as biological markers for temporal processing at different cortical levels. Early oscillatory 40-Hz responses were elicited by the onsets of leading and lagging markers and indicated central registration of the gap with similar amplitude in all three age groups. High-gamma responses were predominantly related to the duration of no-gap stimuli or to the duration of gaps when present, and decreased in amplitude and phase locking with increasing age. Correspondingly, low-frequency activity around 200 ms and later was reduced in middle aged and older participants. High-gamma band, and long-latency low-frequency responses were interpreted as reflecting higher order processes related to the grouping of sound items into auditory objects and updating of memory for these objects. The observed effects indicate that age-related changes in auditory acuity have more to do with higher-order brain functions than previously thought.

Adaptation reveals multiple levels of representation in auditory stream segregation

When presented with alternating low and high tones, listeners are more likely to perceive 2 separate streams of tones ("streaming") than a single coherent stream when the frequency separation (Deltaf) between tones is greater and the number of tone presentations is greater ("buildup"). However, the same large-Deltaf sequence reduces streaming for subsequent patterns presented after a gap of up to several seconds. Buildup occurs at a level of neural representation with sharp frequency tuning. The authors used adaptation to demonstrate that the contextual effect of prior Deltaf arose from a representation with broad frequency tuning, unlike buildup. Separate adaptation did not occur in a representation of Deltaf independent of frequency range, suggesting that any frequency-shift detectors undergoing adaptation are also frequency specific. A separate effect of prior perception was observed, dissociating stimulus-related (i.e., Deltaf) and perception-related (i.e., 1 stream vs. 2 streams) adaptation. Viewing a visual analogue to auditory streaming had no effect on subsequent perception of streaming, suggesting adaptation in auditory-specific brain circuits. These results, along with previous findings on buildup, suggest that processing in at least 3 levels of auditory neural representation underlies segregation and formation of auditory streams.

Pulse and meter as neural resonance

The experience of musical rhythm is a remarkable psychophysical phenomenon, in part because the perception of periodicities, namely pulse and meter, arise from stimuli that are not periodic. One possible function of such a transformation is to enable synchronization between individuals through perception of a common abstract temporal structure (e.g., during music performance). Thus, understanding the brain processes that underlie rhythm perception is fundamental to explaining musical behavior. Here, we propose that neural resonance provides an excellent account of many aspects of human rhythm perception. Our framework is consistent with recent brain-imaging studies showing neural correlates of rhythm perception in high-frequency oscillatory activity, and leads to the hypothesis that perception of pulse and meter result from rhythmic bursts of high-frequency neural activity in response to musical rhythms. High-frequency bursts of activity may enable communication between neural areas, such as auditory and motor cortices, during rhythm perception and production.

Neural encoding of sound duration persists in older adults

Speech perception depends strongly on precise encoding of the temporal structure of sound. Although behavioural studies suggest that communication problems experienced by older adults may entail deficits in temporal acuity, much is unknown about the effects of age on the neural mechanisms underlying the encoding of sound duration. In this study, we measured neuromagnetic auditory evoked responses in young, middle-aged and older healthy participants listening to sounds of various durations. The time courses of cortical activity from bilateral sources in superior temporal planes showed specific differences related to the sound offsets indicating the neural representation of onset and offset markers as one dimension of the neural code for sound duration. Model free MEG source analysis identified brain areas specifically responding with an increase in activity to increases in sound duration in the left anterior insula, right inferior frontal, right middle temporal, and right post-central gyri in addition to bilateral supra-temporal gyri. Sound duration-related changes in cortical responses were comparable in all three age groups despite age-related changes in absolute response magnitudes. The results demonstrated that early cortical encoding of the temporal structure of sound presented in silence is little or not affected by normal aging.

Age-related differences in auditory evoked responses during rapid perceptual learning

OBJECTIVE

Young and older adults can learn to rapidly discriminate between elementary visual and auditory features. While growing evidence supports the notion that such behavioral improvement is paralleled by neuroplastic changes in corresponding sensory areas during adulthood, studies have not examined practice-related improvement in older adults and the corresponding changes in neural activity.

METHODS

We used event-related potentials (ERPs) to investigate the effects of age on rapid learning-related changes in listeners' ability to identify two phonetically different vowels presented simultaneously.

RESULTS

During the first hour of testing, young and older listeners showed comparable behavioral improvement in identifying both vowels. In young adults, learning was paralleled by enhanced amplitudes of early (130 ms) and late (320 ms) ERP waves over the right temporal lobe, as well as an increased negative wave over the midline parietal region, peaking at about 400 ms after sound onset. The practice-related changes over the right temporal lobe were not present in older adults whereas the learning effect observed over the parietal region was present in both young and older adults. In older adults, behavioral improvement was also associated with reduced N1 amplitude recorded at inferior and posterior temporal/occipital scalp sites while no such changes were observed in young adults.

CONCLUSIONS

Age-related differences in neural activity during learning suggest that neural networks supporting behavioral improvements in speech segregation and identification change during the course of aging.

SIGNIFICANCE

This research highlights the role of practice on concurrent sound perception and may facilitate the development of training programs that may help older listeners to parse the auditory scene into component sound sources.

Toward a neurophysiological theory of auditory stream segregation

Auditory stream segregation (or streaming) is a phenomenon in which 2 or more repeating sounds differing in at least 1 acoustic attribute are perceived as 2 or more separate sound sources (i.e., streams). This article selectively reviews psychophysical and computational studies of streaming and comprehensively reviews more recent neurophysiological studies that have provided important insights into the mechanisms of streaming. On the basis of these studies, segregation of sounds is likely to occur beginning in the auditory periphery and continuing at least to primary auditory cortex for simple cues such as pure-tone frequency but at stages as high as secondary auditory cortex for more complex cues such as periodicity pitch. Attention-dependent and perception-dependent processes are likely to take place in primary or secondary auditory cortex and may also involve higher level areas outside of auditory cortex. Topographic maps of acoustic attributes, stimulus-specific suppression, and competition between representations are among the neurophysiological mechanisms that likely contribute to streaming. A framework for future research is proposed.

Relationship between P50 suppression and the cortical silent period

Deficient inhibitory neurotransmission has been demonstrated in schizophrenia through electroencephalography (e.g. P50 suppression) and transcranial magnetic stimulation (e.g. short-interval cortical inhibition and the cortical silent period). It is not known whether these inhibitory paradigms are related despite evidence suggesting that both are coordinated through gamma-aminobutyric acid inhibitory neurotransmission. We explored the relationship between P50 suppression, short-interval cortical inhibition and the cortical silent period in 21 healthy participants using previously published methods. P50 suppression was significantly correlated with cortical silent period (r=-0.49, P=0.02) but not with short-interval cortical inhibition. As both P50 suppression and the cortical silent period have been linked to gamma-aminobutyric acidB receptor-mediated inhibitory neurotransmission, these data highlight the importance of this receptor subtype in the pathophysiology of schizophrenia.

Changes in Auditory Cortex Parallel Rapid Perceptual Learning

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.

Effects of attention on neuroelectric correlates of auditory stream segregation

A general assumption underlying auditory scene analysis is that the initial grouping of acoustic elements is independent of attention. The effects of attention on auditory stream segregation were investigated by recording event-related potentials (ERPs) while participants either attended to sound stimuli and indicated whether they heard one or two streams or watched a muted movie. The stimuli were pure-tone ABA--patterns that repeated for 10.8 sec with a stimulus onset asynchrony between A and B tones of 100 msec in which the A tone was fixed at 500 Hz, the B tone could be 500, 625, 750, or 1000 Hz, and--was a silence. In both listening conditions, an enhancement of the auditory-evoked response (P1-N1-P2 and N1c) to the B tone varied with Deltaf and correlated with perception of streaming. The ERP from 150 to 250 msec after the beginning of the repeating ABA- patterns became more positive during the course of the trial and was diminished when participants ignored the tones, consistent with behavioral studies indicating that streaming takes several seconds to build up. The N1c enhancement and the buildup over time were larger at right than left temporal electrodes, suggesting a right-hemisphere dominance for stream segregation. Sources in Heschl's gyrus accounted for the ERP modulations related to Deltaf-based segregation and buildup. These findings provide evidence for two cortical mechanisms of streaming: automatic segregation of sounds and attention-dependent buildup process that integrates successive tones within streams over several seconds.