Neural correlates of emotional valence for faces and words

: Stimuli with negative emotional valence are especially apt to influence perception and action because of their crucial role in survival, a property that may not be precisely mirrored by positive emotional stimuli of equal intensity. The aim of this study was to identify the neural circuits differentially coding for positive and negative valence in the implicit processing of facial expressions and words, which are among the main ways human beings use to express emotions. Thirty-six healthy subjects took part in an event-related fMRI experiment. We used an implicit emotional processing task with the visual presentation of negative, positive, and neutral faces and words, as primary stimuli. Dynamic Causal Modeling (DCM) of the fMRI data was used to test effective brain connectivity within two different anatomo-functional models, for the processing of words and faces, respectively. In our models, the only areas showing a significant differential response to negative and positive valence across both face and word stimuli were early visual cortices, with faces eliciting stronger activations. For faces, DCM revealed that this effect was mediated by a facilitation of activity in the amygdala by positive faces and in the fusiform face area by negative faces; for words, the effect was mainly imputable to a facilitation of activity in the primary visual cortex by positive words. These findings support a role of early sensory cortices in discriminating the emotional valence of both faces and words, where the effect may be mediated chiefly by the subcortical/limbic visual route for faces, and rely more on the direct thalamic pathway to primary visual cortex for words

Masculinidad(es) en problemas: pandemia, redes sociales y bienestar emocional

El objetivo de este estudio, contextualizado dentro del COVID-19, fue determinar qué ventajas y desventajas enfrenta el género masculino frente al femenino con respecto al manejo y mantenimiento del bienestar emocional. Esto se logró a través de un enfoque cualitativo mixto compuesto por dos etapas: un enfoque netnográfico a perfiles de Instagram (N=5) con contenido sobre el manejo de bienestar emocional y entrevistas semiestructuradas (N=30) a jóvenes del género masculino de entre 18 a 25 años de edad. Se observó que la brecha existente en las prácticas de salud y búsqueda de ayuda para temas de salud mental entre mujeres y hombres se reproduce dentro de estas plataformas. Si bien los estereotipos de género han mutado, lo masculino ha cambiado de manera limitada, pues su inserción y visibilidad en las esferas femeninas es reducida en comparación a la situación inversa

Words hurt: common and distinct neural substrates underlying nociceptive and semantic pain

Introduction: Recent studies have shown that processing semantic pain, such as words associated with physical pain, modulates pain perception and enhances activity in regions of the pain matrix. A direct comparison between activations due to noxious stimulation and processing of words conveying physical pain may clarify whether and to what extent the neural substrates of nociceptive pain are shared by semantic pain. Pain is triggered also by experiences of social exclusion, rejection or loss of significant others (the so-called social pain), therefore words expressing social pain may modulate pain perception similarly to what happens with words associated with physical pain. This event-related fMRI study aims to compare the brain activity related to perceiving nociceptive pain and that emerging from processing semantic pain, i.e., words related to either physical or social pain, in order to identify common and distinct neural substrates. Methods: Thirty-four healthy women underwent two fMRI sessions each. In the Semantic session, participants were presented with positive words, negative pain-unrelated words, physical pain-related words, and social pain-related words. In the Nociceptive session, participants received cutaneous mechanical stimulations that could be either painful or not. During both sessions, participants were asked to rate the unpleasantness of each stimulus. Linguistic stimuli were also rated in terms of valence, arousal, pain relatedness, and pain intensity, immediately after the Semantic session. Results: In the Nociceptive session, the 'nociceptive stimuli' vs. 'non-nociceptive stimuli' contrast revealed extensive activations in SI, SII, insula, cingulate cortex, thalamus, and dorsolateral prefrontal cortex. In the Semantic session, words associated with social pain, compared to negative pain-unrelated words, showed increased activity in most of the same areas, whereas words associated with physical pain, compared to negative pain-unrelated words, only activated the left supramarginal gyrus and partly the postcentral gyrus. Discussion: Our results confirm that semantic pain partly shares the neural substrates of nociceptive pain. Specifically, social pain-related words activate a wide network of regions, mostly overlapping with those pertaining to the affective-motivational aspects of nociception, whereas physical pain-related words overlap with a small cluster including regions related to the sensory-discriminative aspects of nociception. However, most regions of overlap are differentially activated in different conditions

Pain mirrors: Neural correlates of observing self or others' facial expressions of pain

Facial expressions of pain are able to elicit empathy and adaptive behavioral responses in the observer. An influential theory posits that empathy relies on an affective mirror mechanism, according to which emotion recognition relies upon the internal simulation of motor and interoceptive states triggered by emotional stimuli. We tested this hypothesis comparing representations of self or others' expressions of pain in nineteen young healthy female volunteers by means of functional magnetic resonance imaging (fMRI). We hypothesized that one's own facial expressions are more likely to elicit the internal simulation of emotions, being more strictly related to self. Video-clips of the facial expressions of each volunteer receiving either painful or non-painful mechanical stimulations to their right hand dorsum were recorded and used as stimuli in a 2 × 2 (Self/Other; Pain/No-Pain) within-subject design. During each trial, a 2 s video clip was presented, displaying either the subject's own neutral or painful facial expressions (Self No-Pain, SNP; Self Pain, SP), or the expressions of other unfamiliar volunteers (Others' No-Pain, ONP; Others' Pain, OP), displaying a comparable emotional intensity. Participants were asked to indicate whether each video displayed a pain expression. fMRI signals were higher while viewing Pain than No-Pain stimuli in a large bilateral array of cortical areas including middle and superior temporal, supramarginal, superior mesial and inferior frontal (IFG) gyri, anterior insula (AI), anterior cingulate (ACC), and anterior mid-cingulate (aMCC) cortex, as well as right fusiform gyrus. Bilateral activations were also detected in thalamus and basal ganglia. The Self vs. Other contrast showed signal changes in ACC and aMCC, IFG, AI, and parietal cortex. A significant interaction between Self and Pain [(SP vs. SNP) > (OP vs. ONP)] was found in a pre-defined region of aMCC known to be also active during noxious stimulation. These findings demonstrate that the observation of one's own and others' facial expressions share a largely common neural network, but self-related stimuli induce generally higher activations. In line with our hypothesis, selectively greater activity for self pain-related stimuli was found in aMCC, a medial-wall region critical for pain perception and recognition

An EEG-fMRI Study on the Termination of Generalized Spike-And-Wave Discharges in Absence Epilepsy

INTRODUCTION: Different studies have investigated by means of EEG-fMRI coregistration the brain networks related to generalized spike-and-wave discharges (GSWD) in patients with idiopathic generalized epilepsy (IGE). These studies revealed a widespread GSWD-related neural network that involves the thalamus and regions of the default mode network. In this study we investigated which brain regions are critically involved in the termination of absence seizures (AS) in a group of IGE patients. METHODS: Eighteen patients (6 male; mean age 25 years) with AS were included in the EEG-fMRI study. Functional data were acquired at 3T with continuous simultaneous video-EEG recording. Event-related analysis was performed with SPM8 software, using the following regressors: (1) GSWD onset and duration; (2) GSWD offset. Data were analyzed at single-subject and at group level with a second level random effect analysis. RESULTS: A mean of 17 events for patient was recorded (mean duration of 4.2 sec). Group-level analysis related to GSWD onset respect to rest confirmed previous findings revealing thalamic activation and a precuneus/posterior cingulate deactivation. At GSWD termination we observed a decrease in BOLD signal over the bilateral dorsolateral frontal cortex respect to the baseline (and respect to GSWD onset). The contrast GSWD offset versus onset showed a BOLD signal increase over the precuneus-posterior cingulate region bilaterally. Parametric correlations between electro-clinical variables and BOLD signal at GSWD offset did not reveal significant effects. CONCLUSION: The role of the decreased neural activity of lateral prefrontal cortex at GSWD termination deserve future investigations to ascertain if it has a role in promoting the discharge offset, as well as in the determination of the cognitive deficits often present in patients with AS. The increased BOLD signal at precuneal/posterior cingulate cortex might reflect the recovery of neural activity in regions that are "suspended" during spike and waves activity, as previously hypothesized

Pain Mirrors: Neural Correlates of Observing Self or Others’ Facial Expressions of Pain

Facial expressions of pain are able to elicit empathy and adaptive behavioral responses in the observer. An influential theory posits that empathy relies on an affective mirror mechanism, according to which emotion recognition relies upon the internal simulation of motor and interoceptive states triggered by emotional stimuli. We tested this hypothesis comparing representations of self or others’ expressions of pain in nineteen young healthy female volunteers by means of functional magnetic resonance imaging (fMRI). We hypothesized that one’s own facial expressions are more likely to elicit the internal simulation of emotions, being more strictly related to self. Video-clips of the facial expressions of each volunteer receiving either painful or non-painful mechanical stimulations to their right hand dorsum were recorded and used as stimuli in a 2 × 2 (Self/Other; Pain/No-Pain) within-subject design. During each trial, a 2 s video clip was presented, displaying either the subject’s own neutral or painful facial expressions (Self No-Pain, SNP; Self Pain, SP), or the expressions of other unfamiliar volunteers (Others’ No-Pain, ONP; Others’ Pain, OP), displaying a comparable emotional intensity. Participants were asked to indicate whether each video displayed a pain expression. fMRI signals were higher while viewing Pain than No-Pain stimuli in a large bilateral array of cortical areas including middle and superior temporal, supramarginal, superior mesial and inferior frontal (IFG) gyri, anterior insula (AI), anterior cingulate (ACC), and anterior mid-cingulate (aMCC) cortex, as well as right fusiform gyrus. Bilateral activations were also detected in thalamus and basal ganglia. The Self vs. Other contrast showed signal changes in ACC and aMCC, IFG, AI, and parietal cortex. A significant interaction between Self and Pain [(SP vs. SNP) >(OP vs. ONP)] was found in a pre-defined region of aMCC known to be also active during noxious stimulation. These findings demonstrate that the observation of one’s own and others’ facial expressions share a largely common neural network, but self-related stimuli induce generally higher activations. In line with our hypothesis, selectively greater activity for self pain-related stimuli was found in aMCC, a medial-wall region critical for pain perception and recognition

Eight Weddings and Six Funerals: An fMRI Study on Autobiographical Memories

“Autobiographical memory” (AM) refers to remote memories from one's own life. Previous neuroimaging studies have highlighted that voluntary retrieval processes from AM involve different forms of memory and cognitive functions. Thus, a complex and widespread brain functional network has been found to support AM. The present functional magnetic resonance imaging (fMRI) study used a multivariate approach to determine whether neural activity within the AM circuit would recognize memories of real autobiographical events, and to evaluate individual differences in the recruitment of this network. Fourteen right-handed females took part in the study. During scanning, subjects were presented with sentences representing a detail of a highly emotional real event (positive or negative) and were asked to indicate whether the sentence described something that had or had not really happened to them. Group analysis showed a set of cortical areas able to discriminate the truthfulness of the recalled events: medial prefrontal cortex, posterior cingulate/retrosplenial cortex, precuneus, bilateral angular, superior frontal gyri, and early visual cortical areas. Single-subject results showed that the decoding occurred at different time points. No differences were found between recalling a positive or a negative event. Our results show that the entire AM network is engaged in monitoring the veracity of AMs. This process is not affected by the emotional valence of the experience but rather by individual differences in cognitive strategies used to retrieve AMs

“When you’re smiling”: how facial expressions affect visual recognition of emotions

Introduction: Facial expressions can elicit simulation in onlookers, and can thus trigger the subjective experience of the same emotion. Moreover, facial muscles activity occurs automatically during the perception of an emotional facial expression (Dimberg and Thunberg, 1998) and preventing it may interfere with the accuracy of emotion recognition (Ponari et al. 2012). However, whether posing a facial expression can shift the perception of ambiguous expressions, and the possible neural basis of this phenomenon, have not been studied. In the present fMRI study we evaluated the effect of posing a facial expression on the recognition of ambiguous emotional faces. Methods: Twenty-six healthy female subjects (mean age 24 + 5,15 years) took part in the experiment. An fMRI event-related paradigm was used. The volunteers were asked to pose a facial expression (happy -H; disgusted –D; neutral -N) according to an emoticon shown on the screen, then to watch a real face expressing an emotion, finally to indicate whether the emotion perceived was happiness (h) or disgust (d). As stimuli, six different ambiguous emotional faces were used; they were a blend of happy and disgusted faces, built from pictures from the Ekman series (Ekman and Friesen, 1976). Three neutral faces (Ekman and Friesen, 1976) were used as controls. The Interpersonal Reactivity Index (IRI, Albiero et al. 2006) questionnaire for empathy was also administered. Functional data were acquired using a Philips Achieva system at 3T and a gradient-echo echo-planar sequence from 30 axial contiguous slices (TR=2000 ms; 326 volumes x 4 sessions; in-plane matrix= 64x64; voxel size: 3x3x4). fMRI analysis was performed using SPM12 (Wellcome Department of Imaging Neuroscience, London, UK). A double statistical threshold (single-voxel statistics and spatial extent) was used to achieve a combined (i.e., corrected for multiple comparisons) significance level of α < 0.05 (3dClustSim AFNI routine). Results: Behavioural results: Posing a disgusted face increased the percentages of d responses (X2=675,2; p< 0.001; Fig. 1a); whereas posing a happy face increased the h responses (X2=119,3; p< 0.001; Fig. 1a) Functional results: Posing happiness and perceiving disgust with respect to posing happiness and perceiving happiness (Hd vs Hh) activated a widespread functional network comprising several left regions (frontal operculum, insula, SMA, medial frontal gyrus, ACC, and basal ganglia, angular gyrus) as well as the right inferior frontal cortex (Figure 1b top). These areas are known to be involved in the a-modal processing of emotions. Posing a neutral face and perceiving happiness with respect to posing a neutral face and perceiving disgust (Nh vs Nd) activated the right posterior insula (Figure 1b bottom). Finally, in several contrasts we found some clusters of increased activity correlating with scores of some subscales of the IRI questionnaire: in particular, high scores in Empathic Concern correlated with the activity of the precuneus in the Ff vs Fd contrast; Fantasy scores correlated with the activity of the right anterior insula within the Df vs Ff contrast and with posterior cingulate and precuneus in the Dd vs Ff contrast. Conclusions: Perceiving a positive, happy face activated the posterior insula, an area consistently activated by pleasurable touch (Morrison, 2016). Behaviourally, posing an emotion shifts the visual perception of ambiguous expressions towards that same emotion. This effect is modulated by the neural system comprising medial and lateral regions of the prefrontal cortex. We can speculate that a cognitive top-down process from the prefrontal cortex could prevent the sensory-motor simulation elicited by the facial expression in being effective on the recognition of others' facial emotions. References Albiero, P. et al. (2006), Contributo all’adattamento italiano dell’Interpersonal Reactivity Index. Test. PSICOMETRIA Metodol. 13, 107–125. Dimberg U and Thunberg M. (1998), Rapid facial reactions to emotional facial expressions. Scand J Psychol. 1998 Mar;39(1):39-45. Ekman, P. and Friesen, W.V. (1976), Pictures of Facial Affect. Consulting Psychologists Press, Palo Alto, CA. Morrison, I. (2016) ALE meta-analysis reveals dissociable networks for affective and discriminative aspects of touch. Hum. Brain Mapp. 37, 1308–1320. Ponari, M et al. (2012), Mapping Correspondence Between Facial Mimicry and Emotion Recognition in Healthy Subjects. Emotion Vol 12(6), Dec 2012, 1398-1403. Schirmer, A and Adolphs, R (2017), Emotion Perception from Face, Voice, and Touch: Comparisons and Convergence. Trends Cogn Sci. 2017 Mar;21(3):216-228. Söderkvist S. et al. (2018), How the Experience of Emotion is Modulated by Facial Feedback. J Nonverbal Behav. 42(1):129-151

Modulation of neural circuits underlying temporal production by facial expressions of pain.

According to the Scalar Expectancy Theory, humans are equipped with a biological internal clock, possibly modulated by attention and arousal. Both emotions and pain are arousing and can absorb attentional resources, thus causing distortions of temporal perception. The aims of the present single-event fMRI study were to investigate: a) whether observation of facial expressions of pain interferes with time production; and b) the neural network subserving this kind of temporal distortions. Thirty healthy volunteers took part in the study. Subjects were asked to perform a temporal production task and a concurrent gender discrimination task, while viewing faces of unknown people with either pain-related or neutral expressions. Behavioural data showed temporal underestimation (i.e., longer produced intervals) during implicit pain expression processing; this was accompanied by increased activity of right middle temporal gyrus, a region known to be active during the perception of emotional and painful faces. Psycho-Physiological Interaction analyses showed that: 1) the activity of middle temporal gyrus was positively related to that of areas previously reported to play a role in timing: left primary motor cortex, middle cingulate cortex, supplementary motor area, right anterior insula, inferior frontal gyrus, bilateral cerebellum and basal ganglia; 2) the functional connectivity of supplementary motor area with several frontal regions, anterior cingulate cortex and right angular gyrus was correlated to the produced interval during painful expression processing. Our data support the hypothesis that observing emotional expressions distorts subjective time perception through the interaction of the neural network subserving processing of facial expressions with the brain network involved in timing. Within this frame, middle temporal gyrus appears to be the key region of the interplay between the two neural systems

Differential Brain Structural and Functional Patterns in Crohn's Disease Patients are Associated with Different Disease Stages

Lay Summary We found morphological and functional brain changes associated with different stages of disease activity in Crohn's disease. These findings may represent the neural correlates of fatigue, irritable bowel syndrome-like symptoms, and cognitive-emotional impairments; these could be useful for evaluating disease progression.Background Crohn's disease (CD) is an inflammatory, chronic disorder that alternates between a quiescent phase and inflammatory flare-ups. Research has begun to elucidate the impact of CD in modulating brain structure and function. The previous neuroimaging studies mainly involved CD patients in remission (CD-R); therefore, little is known about how inflammation influences brain-related features in different stages of the disease. We carried out a magnetic resonance imaging (MRI) study to explore whether the different levels of disease activity may differentially affect brain structure and function. Methods Fourteen CD-R patients, 19 patients with mild to moderate inflammatory activity (CD-A), and 18 healthy controls (HCs) underwent an MRI scan including structural and functional sequences. Results Between-group comparisons showed morphological and functional brain differences distinctively associated with the stage of disease activity. The CD-A patients had reduced gray matter within the posterior cingulate cortex (PCC) relative to CD-R patients. Analysis on resting fMRI data showed the following patterns: (1) increased connectivity within the left fronto-parietal network (in the superior parietal lobe) in CD-R patients relative to CD-A patients; (2) decreased connectivity in the motor network (in parietal and motor areas) in the CD-A group relative to the HC group; (3) reduced connectivity in the motor network and (4) in the language network (in parietal areas and in the PCC) in CD-R patients relative to HC. Conclusions The present findings represent a further step towards understanding brain morphological and functional changes in the active vs remission stages of CD patients