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People with aphantasia exhibit the inability to voluntarily generate or form mental imagery in their minds. Since the term “aphantasia” was proposed to describe this, it has gained increasing attention from psychiatrists, neuroscientists, and clinicians. Previous studies have mainly focused on the definition, prevalence, and measurement of aphantasia, its impacts on individuals’ cognitive and emotional processing, and theoretical frameworks synthesizing existing findings, which have contributed greatly to our understanding of aphantasia. However, there are still some debates regarding the conclusions derived from existing research and the theories that were constructed from various sources of evidence. Building upon existing endeavors, this systematic review emphasizes that future research is much needed to refine the definition and diagnosis of aphantasia, strengthen empirical investigations at behavioral and neural levels, and, more importantly, develop or update theories. These multiple lines of efforts could lead to a deeper understanding of aphantasia and further guide researchers in future research directions.

AbstractLearning non-native phonetic categories in adulthood is an exceptionally challenging task, characterized by large interindividual differences in learning speed and outcomes. The neurobiological mechanisms underlying the interindividual differences in the learning efficacy are not fully understood. Here we examine the extent to which training-induced neural representations of non-native Mandarin tone categories in English listeners (n = 53) are increasingly similar to those of the native listeners (n = 33) who acquired these categories early in infancy. We assess the extent to which the neural similarities in representational structure between non-native learners and native listeners are robust neuromarkers of interindividual differences in learning success. Using intersubject neural representational similarity (IS-NRS) analysis and predictive modeling on two functional magnetic resonance imaging datasets, we examined the neural representational mechanisms underlying speech category learning success. Learners’ neural representations that were significantly similar to the native listeners emerged in brain regions mediating speech perception following training; the extent of the emerging neural similarities with native listeners significantly predicted the learning speed and outcome in learners. The predictive power of IS-NRS outperformed models with other neural representational measures. Furthermore, neural representations underlying successful learning were multidimensional but cost-efficient in nature. The degree of the emergent native-similar neural representations was closely related to the robustness of neural sensitivity to feedback in the frontostriatal network. These findings provide important insights into the experience-dependent representational neuroplasticity underlying successful speech learning in adulthood and could be leveraged in designing individualized feedback-based training paradigms that maximize learning efficacy.

Eradicating poverty and improving human well-being are pivotal objectives for achieving global sustainable development. Sustainable agriculture, as a key domain, plays a crucial role in addressing poverty. However, to date, there remains insufficient research on the specific impact of agricultural green development on poverty. To bridge this gap, we utilize panel data from 273 prefecture-level cities in China from 2006 to 2022 to explore how agricultural green development affects poverty based on constructing a regional multidimensional poverty index and an index of green agriculture. Our study reveals that agricultural green development effectively reduces poverty, particularly in regions of deep poverty and the eastern part of China. Further mediating analysis indicates the alleviation of poverty by agricultural green development through the infrastructure, the industrial structure, and the green technology innovation effect. Our findings offer valuable insights for informing policies on agricultural green development and poverty reduction, as well as for improving government resource allocation and strengthening resilience in impoverished areas. By deepening our understanding of the link between green agriculture and poverty, this research significantly contributes to global agricultural sustainability and expedites poverty eradication worldwide. [ABSTRACT FROM AUTHOR]

Music is pervasive across human cultures and throughout times. Particularly, music serves great importance at social functions. Like many cultures’ use of music, throat singing or khöömei, the most distinguished aspect of Tuva’s music, contributes significantly to social communication, emotional expression, social bonding and religious rituals. Acknowledgment and consideration of current social cognitive findings of music may thus provide a better insight into the nature of throat singing. To date, evidence has indicated that similar to language, music is a fundamental channel of communication, and these two constructs may have common origins in a single communicative system. Moreover, music may modulate neural activity in the brain structures associated with emotions and alter our autonomic responses. In addition to information sharing, music thus has the capacity to convey emotions. This ability may further render music a powerful mechanism to facilitate social bonding and ritual practice, as individuals’ internal states during these social events become synchronized through musical engagement. In conclusion, I suggest that those social cognitive perspectives may point toward new directions for a continuing discourse on our understanding of throat singing.

Objective Occult clinical presentations usually hinder the early detection and management of patients with bone metastases from thyroid carcinoma. We retrospectively investigated the clinical outcomes of such patients from 1993 to 2004 and analyzed the prognostic parameters. Design The basic demographic data and manifestations of 44 patients who had thyroid carcinoma with bone metastases were reviewed. We studied the gender, age, locations of metastases, histological types, treatment methods, hypercalcemic episodes and results of treatments. We used Kaplan-Meier survival analysis and log-rank tests to access the statistical significance. Main Outcome The incidence of bone metastasis from thyroid carcinomas in this series was 5.0%. Twenty patients (45.4%) had follicular, 16 (36.3%) had papillary, 3 (6.8%) had anaplastic, 3 (6.8%) had medullary, and 2 (4.5%) had Hurthel cell carcinomas. Twelve patients had hypercalcemic episodes, ranging from 2.6 to 2.9 mmolL −1 (mean ± SD: 2.68 ± 0.15 mmolL −1 ). Survival time after bone metastases ranged from 2 months to 8 years (mean ± SD: 5.3 ± 1.3 years). The 5-year survival rate was 79.4% and the 10-year survival rate was 52.9%. Regarding the histological cancer type, patients with papillary and follicular cancers survived significantly longer than those with anaplastic and medullary cancers (p < 0.05). In addition, the patients presenting with hypercalcemia had the worst survival (p < 0.05). Conclusions Thyroid carcinoma can present with bone metastases in its early stage. We found that both tumor type and hypercalcemia were significant prognostic factors for survival time.

This paper proposes an adaptive formation tracking control algorithm optimized by Q-learning scheme for multiple mobile robots. In order to handle the model uncertainties and external disturbances, a desired linear extended state observer is designed to develop an adaptive formation tracking control strategy. Then an adaptive method of sliding mode control parameters optimized by Q-learning scheme is employed, which can avoid the complex parameter tuning process. Furthermore, the stability of the closed-loop control system is rigorously proved by means of matrix properties of graph theory and Lyapunov theory, and the formation tracking errors can be guaranteed to be uniformly ultimately bounded. Finally, simulations are presented to show the proposed algorithm has the advantages of faster convergence rate, higher tracking accuracy, and better steady-state performance. [ABSTRACT FROM AUTHOR]

The growing popularity of digital assistants (from Microsoft's Clippy to Amazon's Alexa) is changing how consumers acquire information and make decisions. Often embodied in anthropomorphized forms, digital assistants (DAs) are designed to serve consumers by suggesting relevant products to simplify purchasing decisions. In this work, we aim to understand how consumers evaluate social relationships with different types of DAs and their subsequent effects on purchasing. Our findings show that consumers judge DAs as being more socially close both when DAs are anthropomorphized and when they provide higher-quality recommendations. Evidence from fMRI indicated that both recommendation quality and anthropomorphization fostered greater feelings of social closeness by recruiting similar brain mechanisms involved in mental simulation (i.e., inferior frontal gyrus and cortical midline structures). Although anthropomorphized DAs were evaluated as more socially close, they did not facilitate increased purchase interest, suggesting that stimulation of neural reward networks is also necessary for driving greater purchasing. [ABSTRACT FROM AUTHOR]

For the output feedback control problem of a T‐S fuzzy system, an H∞ observer‐controller synthesis method is proposed. First, with parallel distributed compensation fuzzy observer and controller, an augmented error system is obtained. Based on Lyapunov function approaches, system stability and robust conditions are achieved. Then, by dividing the non‐convex conditions into observer‐dominant and controller dominant parts, the conditions are converted into convex form to facilitate the numerical solving process. Also, input saturation and system measurement disturbance are considered in the synthesis procedure. Finally, a numerical and a vessel control example are adopted to make comparisons with existing methods, with the results clearly showing the conservatism reduction effects and good control performance of the proposed method. [ABSTRACT FROM AUTHOR]

In contrast to the classic view that facial expressions convey specific emotional states, recent theories have postulated that perception is a highly contextualised phenomenon. The present study utilised sequential effects as a probe to examine how the preceding context informs current facial expression perception, while participants performed a binary categorisation task on a sequence of expressions morphed from fearful to disgusted prototypes. We found that preceding stimuli/responses played differential roles in expression-based sequential effects. When preceding responses were analytically controlled for, the participants were biased to categorise the current targets as being either away from or close to the category of preceding expressions, yielding stimulus-related contrast or assimilation effects, depending on whether the stimulus similarity between the preceding and current expressions was small or large. When the stimulus similarity between successive expressions was analytically controlled for, preceding responses slanted current categorisation judgments toward response-related assimilative consequences. Distinct from stimulus-related contrast, both stimulus-related and response-related assimilations were robust since they could persist for expressions presented up to two trials back and when the perceptual quality of the stimuli was poor. We suggest that the criterion-shift account is generally compatible with the overall findings, revealing how facial expression perception is temporally contextualised. [ABSTRACT FROM AUTHOR]

The phase of low-frequency, rhythmic cortical activity is essential for organizing brain processes because it provides a recurrent temporal frame for information coding. However, the low-frequency cortical phase exhibits great flexibility in response to external influences. Given that brain rhythms have been found to track respiratory inputs, we hypothesized that slow breathing, commonly associated with mental regulation, could reorganize the relationship between these two rhythmic systems through the adjustment of the cortical phase to such a slow train of inputs. Based on simultaneous magnetoencephalography and respiratory measurements, we report that while participants performed paced breathing, slow relative to normal breathing modulated cortical phase activity in the alpha range across widespread brain areas. Such modulation effects were specifically locked to the middle of the inspiration stage and exhibited a well-structured pattern. At the single-subject level, the phase angles underlying the effects became more likely to be diametrically opposed across breaths, indicating unique and consistent phase adjustment to slow inspiratory inputs. Neither cardiac fluctuations nor breathing-unrelated task effects could account for the findings. We suggest that slow-paced inspiration could organize the cortical phase in a regularized phase pattern, revealing a rhythmic but dynamic neural network integrated with different neurophysiological systems through volitional control. [ABSTRACT FROM AUTHOR]

An important issue facing the empirical study of consciousness concerns how the contents of incoming stimuli gain access to conscious processing. According to classic theories, facial stimuli are processed in a hierarchical manner. However, it remains unclear how the brain determines which level of stimulus content is consciously accessible when facing an incoming facial stimulus. Accordingly, with a magnetoencephalography technique, this study aims to investigate the temporal dynamics of the neural mechanism mediating which level of stimulus content is consciously accessible. Participants were instructed to view masked target faces at threshold so that, according to behavioral responses, their perceptual awareness alternated from consciously accessing facial identity in some trials to being able to consciously access facial configuration features but not facial identity in other trials. Conscious access at these two levels of facial contents were associated with a series of differential neural events. Before target presentation, different patterns of phase angle adjustment were observed between the two types of conscious access. This effect was followed by stronger phase clustering for awareness of facial identity immediately during stimulus presentation. After target onset, conscious access to facial identity, as opposed to facial configural features, was able to elicit more robust late positivity. In conclusion, we suggest that the stages of neural events, ranging from prestimulus to stimulus-related activities, may operate in combination to determine which level of stimulus contents is consciously accessed. Conscious access may thus be better construed as comprising various forms that depend on the level of stimulus contents accessed. [ABSTRACT FROM AUTHOR]

Background Phase clustering within a single neurophysiological signal plays a significant role in a wide array of cognitive functions. Inter-trial phase coherence (ITC) is commonly used to assess to what extent phases are clustered in a similar direction over samples. However, this measure is especially dependent on sample size. Although ITC was transformed into ITCz, namely, Rayleigh’s Z, to “correct” for the sample-size effect in previous research, the validity of this strategy has not been formally tested. New method This study introduced cosine similarity (CS) as an alternative solution, as this measure is an unbiased and consistent estimator for finite sample size and is considered less sensitive to the sample-size effect. Results In a series of studies using either artificial or real datasets, CS was robust against sample size variation even with small sample sizes. Moreover, several different aspects of examinations confirmed that CS could successfully detect phase-clustering differences between datasets with different sample sizes. Comparison with existing methods Existing measures suffer from sample-size effects. ITCz produced a mixed pattern of bias in assessing phase clustering according to sample size, whereas ITC overestimated the degree of phase clustering with small sample sizes. Conclusions The current study not only reveals the incompetence of the previous “correction” measure, ITCz, but also provides converging evidence showing that CS may serve as an optimal measure to quantify phase clustering. [ABSTRACT FROM AUTHOR]

Participants performed a priming task during which emotional faces served as prime stimuli and emotional words served as targets. Prime–target pairs were congruent or incongruent, and two levels of prime visibility were obtained by varying the duration of the masked primes. To probe a neural signature of the impact of the masked primes, lateralized readiness potentials (LRPs) were recorded over motor cortex. In the high-visibility condition, responses to word targets were faster when the prime–target pairs were congruent than when they were incongruent, providing evidence of priming effects. In line with the behavioral results, the electrophysiological data showed that high-visibility face primes resulted in LRP differences between congruent and incongruent trials, suggesting that prime stimuli initiated motor preparation. Contrary to the above pattern, no evidence for reaction time or LRP differences was observed in the low-visibility condition, revealing that the depth of facial expression processing is dependent on stimulus visibility. [ABSTRACT FROM AUTHOR]

The effect of adaptation on facial expression recognition was investigated by measuring how identification performance of test stimuli falling along a particular expression continuum was affected after adapting to various prototype emotional faces or a control pattern. The results showed that for recognition of fear, happiness, and sadness, inhibition effects were observed on recognition of test expressions following 5 s adaptation to the same emotion, suggesting different neural populations tuned for the encoding of fearful, happy, and sad expressions. Facilitation of recognition of test stimuli differing in emotion to the adapting stimulus was also sometimes observed. The nature of these adaptation effects was investigated by introducing a size transformation or a delay between adapting and test stimuli and was found to survive these changes. The results of a further experiment argued against a criterion effect being the major source by demonstrating the importance of adapting time in generating the effects. Overall, the present study demonstrates the utility of adaptation effects for revealing functional characteristics of facial expression processing. [ABSTRACT FROM AUTHOR]

The α phase has been theorized to reflect fluctuations in cortical excitability and thereby impose a cyclic influence on visual perception. Despite its appeal, this notion is not fully substantiated, as both supporting and opposing evidence has been recently reported. In contrast to previous research, this study examined the effect of the peristimulus instead of prestimulus phase on visual detection through a real-time phase-locked stimulus presentation (PLSP) approach. Specifically, we monitored phase data from magnetoencephalography (MEG) recordings over time, with a newly developed algorithm based on adaptive Kalman filtering (AKF). This information guided online presentations of masked stimuli that were phased-locked to different stages of the α cycle while healthy humans concurrently performed detection tasks. Behavioral evidence showed that the overall detection rate did not significantly vary according to the four predetermined peristimulus α phases. Nevertheless, the follow-up analyses highlighted that the phase at 90° relative to 180° likely enhanced detection. Corroborating neural parietal activity showed that early interaction between α phases and incoming stimuli orchestrated the neural representation of the hits and misses of the stimuli. This neural representation varied according to the phase and in turn shaped the behavioral outcomes. In addition to directly investigating to what extent fluctuations in perception can be ascribed to the α phases, this study suggests that phase-dependent perception is not as robust as previously presumed, and might also depend on how the stimuli are differentially processed as a result of a stimulus-phase interaction, in addition to reflecting alternations of the perceptual states between phases., (Copyright © 2023 Tseng et al.)

Learning non-native phonetic categories in adulthood is an exceptionally challenging task, characterized by large inter-individual differences in learning speed and outcomes. The neurobiological mechanisms underlying the inter-individual differences in the learning efficacy are not fully understood. Here we examined the extent to which training-induced neural representations of non-native Mandarin tone categories in English listeners ( n = 53) are increasingly similar to those of the native listeners ( n = 33) who acquired these categories early in infancy. We particularly assessed whether the neural similarities in representational structure between non-native learners and native listeners are robust neuromarkers of inter-individual differences in learning success. Using inter-subject neural representational similarity (IS-NRS) analysis and predictive modeling on two functional magnetic resonance imaging (fMRI) datasets, we examined the neural representational mechanisms underlying speech category learning success. Learners' neural representations that were significantly similar to the native listeners emerged in brain regions mediating speech perception following training; the extent of the emerging neural similarities with native listeners significantly predicted the learning speed and outcome in learners. The predictive power of IS-NRS outperformed models with other neural representational measures. Furthermore, neural representations underlying successful learning are multidimensional but cost-efficient in nature. The degree of the emergent native-similar neural representations was closely related to the robust neural sensitivity to feedback in the frontostriatal network. These findings provide important insights on experience-dependent representational neuroplasticity underlying successful speech learning in adulthood and could be leveraged in designing individualized feedback-based training paradigms that maximize learning efficiency., Competing Interests: Conflict of interest statement Patrick C. M. Wong is a founder of a company in Hong Kong supported by a Hong Kong SAR government startup scheme for universities.

The phase of low-frequency, rhythmic cortical activity is essential for organizing brain processes because it provides a recurrent temporal frame for information coding. However, the low-frequency cortical phase exhibits great flexibility in response to external influences. Given that brain rhythms have been found to track respiratory inputs, we hypothesized that slow breathing, commonly associated with mental regulation, could reorganize the relationship between these two rhythmic systems through the adjustment of the cortical phase to such a slow train of inputs. Based on simultaneous magnetoencephalography and respiratory measurements, we report that while participants performed paced breathing, slow relative to normal breathing modulated cortical phase activity in the alpha range across widespread brain areas. Such modulation effects were specifically locked to the middle of the inspiration stage and exhibited a well-structured pattern. At the single-subject level, the phase angles underlying the effects became more likely to be diametrically opposed across breaths, indicating unique and consistent phase adjustment to slow inspiratory inputs. Neither cardiac fluctuations nor breathing-unrelated task effects could account for the findings. We suggest that slow-paced inspiration could organize the cortical phase in a regularized phase pattern, revealing a rhythmic but dynamic neural network integrated with different neurophysiological systems through volitional control. NEW & NOTEWORTHY Breathing is more complicated than a simple gas exchange, as it is integrated with numerous cognitive and emotional functions. Controlled slow breathing has often been used to regulate mental processes. This magnetoencephalography study demonstrates that slow-paced relative to normal-paced inspiration could organize the timing of alpha rhythmic activities across breathing cycles in a structured manner over widespread brain areas. Our results reveal how a volitionally controlled change in respiratory behavior could systematically modulate cortical activity.

An important issue facing the empirical study of consciousness concerns how the contents of incoming stimuli gain access to conscious processing. According to classic theories, facial stimuli are processed in a hierarchical manner. However, it remains unclear how the brain determines which level of stimulus content is consciously accessible when facing an incoming facial stimulus. Accordingly, with a magnetoencephalography technique, this study aims to investigate the temporal dynamics of the neural mechanism mediating which level of stimulus content is consciously accessible. Participants were instructed to view masked target faces at threshold so that, according to behavioral responses, their perceptual awareness alternated from consciously accessing facial identity in some trials to being able to consciously access facial configuration features but not facial identity in other trials. Conscious access at these two levels of facial contents were associated with a series of differential neural events. Before target presentation, different patterns of phase angle adjustment were observed between the two types of conscious access. This effect was followed by stronger phase clustering for awareness of facial identity immediately during stimulus presentation. After target onset, conscious access to facial identity, as opposed to facial configural features, was able to elicit more robust late positivity. In conclusion, we suggest that the stages of neural events, ranging from prestimulus to stimulus-related activities, may operate in combination to determine which level of stimulus contents is consciously accessed. Conscious access may thus be better construed as comprising various forms that depend on the level of stimulus contents accessed. NEW & NOTEWORTHY The present study investigates how the brain determines which level of stimulus contents is consciously accessible when facing an incoming facial stimulus. Using magnetoencephalography, we show that prestimulus activities together with stimulus-related activities may operate in combination to determine conscious face detection or identification. This finding is distinct from the previous notion that conscious face detection precedes identification and provides novel insights into the temporal dynamics of different levels of conscious face perception.