Supramodal parametric working memory processing in humans

Previous studies of delayed-match-to-sample (DMTS) frequency discrimination in animals and humans have succeeded in delineating the neural signature of frequency processing in somatosensory working memory (WM). During retention of vibrotactile frequencies, stimulus-dependent single-cell and population activity in prefrontal cortex was found to reflect the task-relevant memory content, whereas increases in occipital alpha activity signaled the disengagement of areas not relevant for the tactile task. Here, we recorded EEG from human participants to determine the extent to which these mechanisms can be generalized to frequency retention in the visual and auditory domains. Subjects performed analogous variants of a DMTS frequency discrimination task, with the frequency information presented either visually, auditorily, or by vibrotactile stimulation. Examining oscillatory EEG activity during frequency retention, we found characteristic topographical distributions of alpha power over visual, auditory, and somatosensory cortices, indicating systematic patterns of inhibition and engagement of early sensory areas, depending on stimulus modality. The task-relevant frequency information, in contrast, was found to be represented in right prefrontal cortex, independent of presentation mode. In each of the three modality conditions, parametric modulations of prefrontal upper beta activity (20-30 Hz) emerged, in a very similar manner as recently found in vibrotactile tasks. Together, the findings corroborate a view of parametric WM as supramodal internal scaling of abstract quantity information and suggest strong relevance of previous evidence from vibrotactile work for a more general framework of quantity processing in human working memory.     

Supramodal effects of galvanic vestibular stimulation on the subjective vertical

This study investigated whether the tilt of the subjective vertical induced by galvanic vestibular stimulation, demonstrated by asking subjects to set a rod to the vertical, was specific to the visual modality or could be found in two tasks relying on proprioceptive and somatosensory cues. In all cases, settings were significantly deviated in the direction of the anode, but errors were smaller in the somatosensory tasks than in the visual task. We propose that the effects observed in the somatosensory modality reflects only a modification of the central representation of gravity, whereas visual effects are also in part the consequence of unregistered ocular torsion.     

Supramodal neural networks support top‐down processing of social signals

The perception of facial and vocal stimuli is driven by sensory input and cognitive top‐down influences. Important top‐down influences are attentional focus and supramodal social memory representations. The present study investigated the neural networks underlying these top‐down processes and their role in social stimulus classification. In a neuroimaging study with 45 healthy participants, we employed a social adaptation of the Implicit Association Test. Attentional focus was modified via the classification task, which compared two domains of social perception (emotion and gender), using the exactly same stimulus set. Supramodal memory representations were addressed via congruency of the target categories for the classification of auditory and visual social stimuli (voices and faces). Functional magnetic resonance imaging identified attention‐specific and supramodal networks. Emotion classification networks included bilateral anterior insula, pre‐supplementary motor area, and right inferior frontal gyrus. They were pure attention‐driven and independent from stimulus modality or congruency of the target concepts. No neural contribution of supramodal memory representations could be revealed for emotion classification. In contrast, gender classification relied on supramodal memory representations in rostral anterior cingulate and ventromedial prefrontal cortices. In summary, different domains of social perception involve different top‐down processes which take place in clearly distinguishable neural networks.     

Supramodal effects of covert spatial orienting triggered by visual or tactile events

Event-related functional magnetic resonance imaging was used to identify brain areas involved in spatial attention and determine whether these operate unimodally or supramodally for vision and touch. On a trial-by-trial basis, a symbolic auditory cue indicated the most likely side for the subsequent target, thus directing covert attention to one side. A subsequent target appeared in vision or touch on the cued or uncued side. Invalidly cued trials (as compared with valid trials) activated the temporo-parietal junction and regions of inferior frontal cortex, regardless of target modality. These brain areas have been associated with multimodal spatial coding in physiological studies of the monkey brain and were linked to a change in the location that must be attended to in the present study. The intraparietal sulcus and superior frontal cortex were also activated in our task, again, regardless of target modality, but did not show any specificity for invalidly cued trials. These results identify a supramodal network for spatial attention and reveal differential activity for inferior circuits involving the temporo-parietal junction and inferior frontal cortex (specific to invalid trials) versus more superior intraparietal-frontal circuits (common to valid and invalid trials).     

Supramodal language comprehension: role of the left temporal lobe for listening and reading

In this fMRI study, we aimed at identifying the cortical areas engaged in supramodal processing of language comprehension. BOLD changes were recorded in 19 healthy right-handed subjects reading or listening to a story. During the visual control tasks the volunteers attended to a series of continuous letterstrings or a fixation cross, while during the acoustic control tasks either a reversed text or white noise were presented. The conjunction of the visual and acoustic story processing yielded left-dominant activations which in comparison to language-like stimuli focused to the left middle temporal gyrus as well as to the supramarginal gyrus. We conclude that the core structure representing supramodal language comprehension is the left temporal lobe at both banks of the superior temporal sulcus.     

Rational emotions

We present here the concept of rational emotions: Emotions may be directly controlled and utilized in a conscious, analytic fashion, enabling an individual to size up a situation, to determine that a certain "mental state" is strategically advantageous and adjust accordingly. Building on the growing body of literature recognizing the vital role of emotions in determining decisions, we explore the complementary role of rational choice in choosing emotional states. Participants played the role of "recipient" in the dictator game, in which an anonymous "dictator" decides how to split an amount of money between himself and the recipient. A subset of recipients was given a monetary incentive to be angry at low-split offers. That subset demonstrated increased physiological arousal at low offers relative to high offers as well as more anger than other participants. These results provide a fresh outlook on human decision-making and contribute to the continuing effort to build more complete models of rational behavior.     

The neurobiology of positive emotions

Compared to the study of negative emotions such as fear, the neurobiology of positive emotional processes and the associated positive affect (PA) states has only recently received scientific attention. Biological theories conceptualize PA as being related to (i) signals indicating that bodies are returning to equilibrium among those studying homeostasis, (ii) utility estimation among those favoring neuroeconomic views, and (iii) approach and other instinctual behaviors among those cultivating neuroethological perspectives. Indeed, there are probably several distinct forms of positive affect, but all are closely related to ancient sub-neocortical limbic brain regions we share with other mammals. There is now a convergence of evidence to suggest that various regions of the limbic system, including especially ventral striatal dopamine systems are implemented in an anticipatory (appetitive) positive affective state. Dopamine independent mechanisms utilizing opiate and GABA receptors in the ventral striatum, amygdala and orbital frontal cortex are important in elaborating consummatory PA (i.e. sensory pleasure) states, and various neuropeptides mediate homeostatic satisfactions.     

Negative emotions and anosognosia

Patients with anosognosia fail to acknowledge, or feel distressed by, their disability. Given the recent suggestion that right (frontal) systems are selectively involved in negative emotions, it might be claimed that anosognosia results from a disruption in negative emotions. This is not consistent with the finding that some anosognosic patients exhibit substantial fluctuations in emotion, including the experience of negative emotions such as sadness. The present study investigates a patient (IW) with a right convexity lesion and anosognosia. He reported being frequently overcome by powerful emotions, especially sadness. IW was assessed on a self-report emotion questionnaire, where his reports were typically of higher levels of emotion than the control group. He was also assessed on the more indirect measure of Affective Story Recall. Here his pattern of emotional experience was similar to that of two control groups, one of which consisted of non-anosognosic patients with hemiparesis. His performance on Story Recall was notable in that he directed his emotions to a different 'object' to that of controls (other vs. self, respectively). These findings are not consistent with any claim that anosognosia results from an absence of negative emotions.     

The plasticity of social emotions

Social emotions such as empathy or compassion greatly facilitate our interactions with others. Despite the importance of social emotions, scientific studies have only recently revealed functional neural plasticity associated with the training of such emotions. Using the framework of two antagonistic neural systems, the threat and social disconnection system on the one hand, and the reward and social connection system on the other, this article describes how training compassion and empathy can change the functioning of these systems in a targeted manner. Whereas excessive empathic sharing of suffering can increase negative feelings and activations in the insula and anterior cingulate cortex (corresponding to the threat and social disconnection system), compassion training can strengthen positive affect and neural activations in the medial orbitofrontal cortex and striatum (corresponding to the reward and social connection system). These neuroimaging findings are complemented by results from behavioral studies showing that compassion is linked to helping and forgiveness behavior, whereas empathic distress not only decreases helping behavior, but is even associated with increased aggressive behavior. Taken together, these data provide encouraging evidence for the plasticity of adaptive social emotions with wide-ranging implications for basic science and applied settings.     

Amusia Due to Rhythm Agnosia in a Musician with Left Hemisphere Damage: A Non-Auditory Supramodal Defect

A case of a severe receptive and expressive amusia in a professional musician following a left hemisphere vascular stroke is reported. Recognition and production of single tones and random tone sequences were found to be surprisingly well preserved. In contrast, the recognition and production of simple rhythm patterns were grossly disturbed. It is suggested that amusia is due to the demonstrated rhythm disturbance. Moreover, it has been found that the defect in recognition and reproduction of rhythms was manifested regardless of the modality of perception, i.e. whether rhythm patterns were perceived by audition, vision, or touch. Therefore, the, disturbance of rhythm abilities is supramodal in nature, based probably on the perception of time microintervals. Thus, this type of amusia is a result of a non-auditory supramodal defect, i.e., an impairment of temporal pattern recognition.     

Right hemisphere patients''judgements on emotions

A triadic comparison technique was used to assess brain-damaged patients' ability to judge the relatedness of a number of emotions, using either a pictorial or verbal material. Emotionally neutral material served as a control. Right hemisphere patients also differed from normals in processing emotions when presented with verbal material. It is suggested that central rather than only peripheral aspects in recognition of emotions are disturbed after injury to the right hemisphere.     

Update on "expressed emotions"

The present article is meant to sum up the current state of scientific knowledge with regard to the concept of "Emotional Expression" and its very implementation in the clinical and therapeutical field which are well-known in anglo-saxon countries but very little applied and known in France. "Emotional Expression" (EE), which came out of research and studies undertaken by Brown (1959) and later on, Vaughn and Leff (1976), defines interaction between a schizophrenic patient and his close environment according to 3 criterium: judgmental comments and criticism, hostility, emotional over-involvement. Family surroundings are characterized by strong EE or weak EE according to the frequency and the quantity of the measures during a typical standard family-interview: the Camberwell Family Interview (CFI). A strong EE is considered as being a non-specific factor. "Emotional Expression" proves to be a predictable indication for relapse in terms of psychiatric affluence (positive symptoms), hospitalization rate and psycho-social adjustment process. The possibilities of forecasting do not concern specifically schizophrenia as the relation between family climate and relapse can be observed in other mental pathology as well. The psycho-educational approach which is induced by this research trend is based on a concept of a partnership between the patients's family and the patient. The purpose in fact is to bring about changes within the relationship of the patient and his environment so as to reduce judgmental criticism, hostility and emotional over-involvement (information programs concerning etiology, therapeutical strategies in view of improving understanding of the illness and to reorganize proper family relationship). The advantage of such a concept which is well-known lies in the fact that it helps to find out those family surroundings with strong EE who represent factors of relapse for psychiatric patients and to suggest therefore therapeutical treatment, the purpose of which should be defined together with all those concerned namely, the patient, the family, the therapeutist so as to intervene during the evolution of the illness. The literary bibliographical review which we have made lead us to find the existence of a wide field of research with results showing clearly the predictable aspects of EE in the illness process. In this way, new approaches in the "intake" of schizophrenic patients and their families are clearly defined.