Different hemispheric roles in recognition of happy expressions

Apragmatism: The renewal of a label for communication disorders associated with right hemisphere brain damage

BACKGROUND

Right hemisphere communication disorders are neither consistently labelled nor adequately defined. Labels associated with right hemisphere brain damage (RHD) are broad and fail to capture the essence of communication challenges needed for stroke-related service provisions. Determination of rehabilitation needs and best-practice guidelines for the education, management and functional improvement of communication disorders after RHD are all predicated on an apt diagnostic label and disorder characteristics.

AIMS

In this paper apragmatism is proposed as a potential communication-specific diagnostic label for the impairments in communication that occur after RHD. In particular, the researchers aimed: (1) to establish an operational definition of apragmatism; and (2) to describe the linguistic, paralinguistic and extralinguistic communication deficits under the umbrella term apragmatism.

METHODS & PROCEDURES

An international collaborative of researchers with expertise in RHD followed a multilevel approach to consider the utility of apragmatism as a diagnostic label. Adopting the relational approach to concept mapping, the researchers engaged in a series of group meetings to complete four levels of mapping: (1) identify and review, (2) define, (3) expert discussion and (4) label determination.

MAIN CONTRIBUTION

Apragmatism was established as a suitable diagnostic label for the impairments in communication associated with RHD. The paper offers an operational definition and description of the linguistic, paralinguistic and extralinguistic features of apragmatism through evidence summaries and examples from people with RHD retrieved from the RHDBank.

CONCLUSIONS & IMPLICATIONS

The adoption of the term apragmatism offers an opportunity to capture the hallmark of RHD communication deficits. The use of the term is recommended when referencing the pragmatic language impairments in this population. Apragmatism, which may co-occur with or be exacerbated by cognitive impairments, can interfere with the ability to interpret and convey intended meaning and impact the lives of right hemisphere stroke survivors and their families.

WHAT THIS PAPER ADDS

What is already known on the subject RHD results in a heterogeneous group of deficits that range in cognitive-communicative complexity. Many of the deficits are subsumed under pragmatics. For example, adults with RHD may demonstrate tangential or verbose communication, insensitivity to others' needs and feelings, prosodic changes, minimal gesture use and facial expression, and more. While descriptions of pragmatic impairments pervade the literature, there is no consistently used diagnostic label. The clinical consequences of this absence include difficulty with inter- and intra-disciplinary communication about these patients, difficulty consolidating findings across research studies, and challenges in communicating about these pragmatic changes with patients, families and other stakeholders. What this paper adds to existing knowledge The term apragmatism is proposed as a diagnostic label to consistently describe pragmatic communication changes after RHD. Apragmatism is characterized using three components of pragmatics: linguistic, paralinguistic and extralinguistic. Descriptions and examples of these three components are provided with supplemental transcripts retrieved from the RHDBank. What are the potential or actual clinical implications of this work? Adoption of the term apragmatism by speech and language therapists and other medical and rehabilitation professionals has the potential to provide consistency in describing the abilities and challenges experienced by people following a right hemisphere stroke. Such improvements may help drive the development of evidence-based assessments and treatments for this population.

Increased Right Dorsolateral Prefrontal Cortex Connectivity During Emotion Recognition Task in Adolescents With Self-Injurious Behavior: A Functional Near-Infrared Spectroscopy Study

OBJECTIVE

Research on neural correlates in the prefrontal cortex (PFC) associated with self-injurious behavior has mainly been performed in adults. However, studies on adolescents are scarce. We aimed to investigate the activation and connectivity of the PFC between adolescents with self-injurious behavior (ASI) and psychiatric controls (PC) using functional near-infrared spectroscopy (fNIRS).

METHODS

We used an emotion recognition task during fNIRS to assess 37 adolescents (23 with self-injurious behavior and 14 PC) between June 2020 and October 2021 and compared connectivity and activation between the two groups. We also measured adverse childhood events (ACE, Adverse Childhood Experiences) and performed a correlation analysis of channel activation according to ACE total scores.

RESULTS

The difference in activation between the groups was not statistically significant. The connectivity of channel 6 was statistically significant. The interaction between channel 6 and the ACE total score showed statistical significance between the two groups(t[33] -2.61; p=0.014). The ASI group showed a negative correlation with the total ACE score.

CONCLUSION

This is the first study to investigate PFC connectivity using fNIRS in ASI. It has the implication of a novel attempt with a practically useful tool to uncover neurobiological differences among Korean adolescents.

Social signalling as a framework for second-person neuroscience

Despite the recent increase in second-person neuroscience research, it is still hard to understand which neurocognitive mechanisms underlie real-time social behaviours. Here, we propose that social signalling can help us understand social interactions both at the single- and two-brain level in terms of social signal exchanges between senders and receivers. First, we show how subtle manipulations of being watched provide an important tool to dissect meaningful social signals. We then focus on how social signalling can help us build testable hypotheses for second-person neuroscience with the example of imitation and gaze behaviour. Finally, we suggest that linking neural activity to specific social signals will be key to fully understand the neurocognitive systems engaged during face-to-face interactions.

Positive hysteresis in emotion recognition: Face processing visual regions are involved in perceptual persistence, which mediates interactions between anterior insula and medial prefrontal cortex

Facial emotion perception can be studied from the point of view of dynamic systems whose output may depend not only on current input but also on prior history - a phenomenon known as hysteresis. In cognitive neuroscience, hysteresis has been described as positive (perceptual persistence) or negative (fatigue of current percept) depending on whether perceptual switching occurs later or earlier than actual physical stimulus changes. However, its neural correlates remain elusive. We used dynamic transitions between emotional expressions and combined behavioral assessment with functional magnetic resonance imaging (fMRI) to investigate the underlying circuitry of perceptual hysteresis in facial emotion recognition. Our findings revealed the involvement of face-selective visual areas - fusiform face area (FFA) and superior temporal sulcus (STS) - in perceptual persistence as well as the right anterior insula. Moreover, functional connectivity analyses revealed an interplay between the right anterior insula and medial prefrontal cortex, which showed to be dependent on the presence of positive hysteresis. Our results support the hypothesis that high-order regions are involved in perceptual stabilization and decision during perceptual persistence (positive hysteresis) and add evidence to the role of the anterior insula as a hub of sensory information in perceptual decision-making.

Facial and neural mechanisms during interactive disclosure of biographical information

Pairs of participants mutually communicated (or not) biographical information to each other. By combining simultaneous eye-tracking, face-tracking and functional near-infrared spectroscopy, we examined how this mutual sharing of information modulates social signalling and brain activity. When biographical information was disclosed, participants directed more eye gaze to the face of the partner and presented more facial displays. We also found that spontaneous production and observation of facial displays was associated with activity in the left SMG and right dlPFC/IFG, respectively. Moreover, mutual information-sharing increased activity in bilateral TPJ and left dlPFC, as well as cross-brain synchrony between right TPJ and left dlPFC. This suggests that a complex long-range mechanism is recruited during information-sharing. These multimodal findings support the second-person neuroscience hypothesis, which postulates that communicative interactions activate additional neurocognitive mechanisms to those engaged in non-interactive situations. They further advance our understanding of which neurocognitive mechanisms underlie communicative interactions.

The theta burst transcranial magnetic stimulation over the right PFC affects electroencephalogram oscillation during emotional processing

Prefrontal cortex (PFC) plays an important role in emotional processing and therefore is one of the most frequently targeted regions for non-invasive brain stimulation such as repetitive transcranial magnetic stimulation (rTMS) in clinical trials, especially in the treatment of emotional disorders. As an approach to enhance the effectiveness of rTMS, continuous theta burst stimulation (cTBS) has been demonstrated to be efficient and safe. However, it is unclear how cTBS affects brain processes related to emotion. In particular, psychophysiological studies on the underlying neural mechanisms are sparse. In the current study, we investigated how the cTBS influences emotional processing when applied over the right PFC. Participants performed an emotion recognition Go/NoGo task, which asked them to select a GO response to either happy or fearful faces after the cTBS or after sham stimulation, while 64-channel electroencephalogram (EEG) was recorded. EEG oscillation was examined using event-related spectral perturbation (ERSP) in a time-interval between 170 and 310ms after face stimuli onset. In the sham group, we found a significant difference in the alpha band between response to happy and fearful stimuli but that effect did not exist in the cTBS group. The alpha band activity at the scalp was reduced suggesting the excitatory effect at the brain level. The beta and gamma band activity was not sensitive to cTBS intervention. The results of the current study demonstrate that cTBS does affect emotion processing and the effect is reflected in changes in EEG oscillations in the alpha band specifically. The results confirm the role of prefrontal cortex in emotion processing. We also suggest that this pattern of cTBS results elucidates mechanisms by which mood improvement in depressive disorders is achieved using cTBS intervention.

Basic Emotions in Human Neuroscience: Neuroimaging and Beyond

The existence of so-called ‘basic emotions’ and their defining attributes represents a long lasting and yet unsettled issue in psychology. Recently, neuroimaging evidence, especially related to the advent of neuroimaging meta-analytic methods, has revitalized this debate in the endeavor of systems and human neuroscience. The core theme focuses on the existence of unique neural bases that are specific and characteristic for each instance of basic emotion. Here we review this evidence, outlining contradictory findings, strengths and limits of different approaches. Constructionism dismisses the existence of dedicated neural structures for basic emotions, considering that the assumption of a one-to-one relationship between neural structures and their functions is central to basic emotion theories. While these critiques are useful to pinpoint current limitations of basic emotions theories, we argue that they do not always appear equally generative in fostering new testable accounts on how the brain relates to affective functions. We then consider evidence beyond PET and fMRI, including results concerning the relation between basic emotions and awareness and data from neuropsychology on patients with focal brain damage. Evidence from lesion studies are indeed particularly informative, as they are able to bring correlational evidence typical of neuroimaging studies to causation, thereby characterizing which brain structures are necessary for, rather than simply related to, basic emotion processing. These other studies shed light on attributes often ascribed to basic emotions, such as automaticity of perception, quick onset, and brief duration. Overall, we consider that evidence in favor of the neurobiological underpinnings of basic emotions outweighs dismissive approaches. In fact, the concept of basic emotions can still be fruitful, if updated to current neurobiological knowledge that overcomes traditional one-to-one localization of functions in the brain. In particular, we propose that the structure-function relationship between brain and emotions is better described in terms of pluripotentiality, which refers to the fact that one neural structure can fulfill multiple functions, depending on the functional network and pattern of co-activations displayed at any given moment.

On the domain-specificity of the visual and non-visual face-selective regions

What happens in our brains when we see a face? The neural mechanisms of face processing - namely, the face-selective regions - have been extensively explored. Research has traditionally focused on visual cortex face-regions; more recently, the role of face-regions outside the visual cortex (i.e., non-visual-cortex face-regions) has been acknowledged as well. The major quest today is to reveal the functional role of each this region in face processing. To make progress in this direction, it is essential to understand the extent to which the face-regions, and particularly the non-visual-cortex face-regions, process only faces (i.e., face-specific, domain-specific processing) or rather are involved in a more domain-general cognitive processing. In the current functional MRI study, we systematically examined the activity of the whole face-network during face-unrelated reading task (i.e., written meaningful sentences with content unrelated to faces/people and non-words). We found that the non-visual-cortex (i.e., right lateral prefrontal cortex and posterior superior temporal sulcus), but not the visual cortex face-regions, responded significantly stronger to sentences than to non-words. In general, some degree of sentence selectivity was found in all non-visual-cortex cortex. Present result highlights the possibility that the processing in the non-visual-cortex face-selective regions might not be exclusively face-specific, but rather more or even fully domain-general. In this paper, we illustrate how the knowledge about domain-general processing in face-regions can help to advance our general understanding of face processing mechanisms. Our results therefore suggest that the problem of face processing should be approached in the broader scope of cognition in general.

The effect of Ramadan fasting on spatial attention through emotional stimuli

Fasting can influence psychological and mental states. In the current study, the effect of periodical fasting on the process of emotion through gazed facial expression as a realistic multisource of social information was investigated for the first time. The dynamic cue-target task was applied via behavior and event-related potential measurements for 40 participants to reveal the temporal and spatial brain activities – before, during, and after fasting periods. The significance of fasting included several effects. The amplitude of the N1 component decreased over the centroparietal scalp during fasting. Furthermore, the reaction time during the fasting period decreased. The self-measurement of deficit arousal as well as the mood increased during the fasting period. There was a significant contralateral alteration of P1 over occipital area for the happy facial expression stimuli. The significant effect of gazed expression and its interaction with the emotional stimuli was indicated by the amplitude of N1. Furthermore, the findings of the study approved the validity effect as a congruency between gaze and target position, as indicated by the increment of P3 amplitude over centroparietal area as well as slower reaction time from behavioral response data during incongruency or invalid condition between gaze and target position compared with those during valid condition. Results of this study proved that attention to facial expression stimuli as a kind of communicative social signal was affected by fasting. Also, fasting improved the mood of practitioners. Moreover, findings from the behavioral and event-related potential data analyses indicated that the neural dynamics of facial emotion are processed faster than that of gazing, as the participants tended to react faster and prefer to relay on the type of facial emotions than to gaze direction while doing the task. Because of happy facial expression stimuli, right hemisphere activation was more than that of the left hemisphere. It indicated the consistency of the emotional lateralization concept rather than the valence concept of emotional processing.

Impairments in Negative Facial Emotion Recognition in Chinese Schizophrenia Patients Detected With a Newly Designed Task

Facial emotion recognition has been found to be impaired in schizophrenia, although overall results have been inconclusive. A new set of facial emotion stimuli with Chinese faces was developed, using static and dynamic avatars, the identification of which were subsequently validated in 562 healthy control subjects. This test was then used to identify facial emotion recognition accuracy in 44 patients with schizophrenia and 41 healthy controls. Overall, patients identified facial emotions significantly worse than healthy controls (p = 0.018) with a significant main effect for type of emotion (p = 0.016). Patients performed significantly worse in fear (p = 0.029) and sadness (p = 0.037), and marginally worse in anger (p = 0.052). No significant differences were evident in contempt (p = 0.254) or happiness (p = 0.943). Regarding error rates of misattribution, patients overidentified contempt (p = 0.035) and sadness (p = 0.01), but not anger, fear, or happiness. Conclusion, patients of Chinese ethnicity with schizophrenia may have significantly greater difficulties identifying negative, but not positive emotions.

Transcranial Electrical Stimulation over Dorsolateral Prefrontal Cortex Modulates Processing of Social Cognitive and Affective Information

Recent neurofunctional studies suggested that lateral prefrontal cortex is a domain-general cognitive control area modulating computation of social information. Neuropsychological evidence reported dissociations between cognitive and affective components of social cognition. Here, we tested whether performance on social cognitive and affective tasks can be modulated by transcranial direct current stimulation (tDCS) over dorsolateral prefrontal cortex (DLPFC). To this aim, we compared the effects of tDCS on explicit recognition of emotional facial expressions (affective task), and on one cognitive task assessing the ability to adopt another person’s visual perspective. In a randomized, cross-over design, male and female healthy participants performed the two experimental tasks after bi-hemispheric tDCS (sham, left anodal/right cathodal, and right anodal/left cathodal) applied over DLPFC. Results showed that only in male participants explicit recognition of fearful facial expressions was significantly faster after anodal right/cathodal left stimulation with respect to anodal left/cathodal right and sham stimulations. In the visual perspective taking task, instead, anodal right/cathodal left stimulation negatively affected both male and female participants’ tendency to adopt another’s point of view. These findings demonstrated that concurrent facilitation of right and inhibition of left lateral prefrontal cortex can speed-up males’ responses to threatening faces whereas it interferes with the ability to adopt another’s viewpoint independently from gender. Thus, stimulation of cognitive control areas can lead to different effects on social cognitive skills depending on the affective vs. cognitive nature of the task, and on the gender-related differences in neural organization of emotion processing.