Negative valence specific deficits in judgements of musical affective quality in alexithymia

Alexithymia modulates emotion concept activation during facial expression processing

Alexithymia is characterized by difficulties in emotional information processing. However, the underlying reasons for emotional processing deficits in alexithymia are not fully understood. The present study aimed to investigate the mechanism underlying emotional deficits in alexithymia. Using the Toronto Alexithymia Scale-20, we recruited college students with high alexithymia (n = 24) or low alexithymia (n = 24) in this study. Participants judged the emotional consistency of facial expressions and contextual sentences while recording their event-related potentials. Behaviorally, the high alexithymia group showed longer response times versus the low alexithymia group in processing facial expressions. The event-related potential results showed that the high alexithymia group had more negative-going N400 amplitudes compared with the low alexithymia group in the incongruent condition. More negative N400 amplitudes are also associated with slower responses to facial expressions. Furthermore, machine learning analyses based on N400 amplitudes could distinguish the high alexithymia group from the low alexithymia group in the incongruent condition. Overall, these findings suggest worse facial emotion perception for the high alexithymia group, potentially due to difficulty in spontaneously activating emotion concepts. Our findings have important implications for the affective science and clinical intervention of alexithymia-related affective disorders.

Emotional recognition across the adult lifespan: Effects of age, sex, cognitive empathy, alexithymia traits, and amygdala subnuclei volumes

The ability to recognize others' emotions is vital to everyday life. The goal of this study was to assess which emotions show age-related decline in recognition accuracy of facial emotional expressions across the entire adult lifespan and how this process is related to cognitive empathy (Theory of Mind [ToM]), alexithymia traits, and amygdala subnuclei volumes in a large cohort of healthy individuals. We recruited 140 healthy participants 18-85 years old. Facial affect processing was assessed with the Penn Emotion Recognition task (ER40) that contains images of the five basic emotions: Neutral, Happy, Sad, Angry, and Fearful. Structural magnetic resonance imaging (MRI) datasets were acquired on a 4.7T MRI system. Structural equation modeling was used to test the relationship between studied variables. We found that while both sexes demonstrated age-related reduction in recognition of happy emotions and preserved recognition of sadness, male participants showed age-related reduction in recognition of fear, while in female participants, age-related decline was linked to recognition of neutral and angry facial expressions. In both sexes, accurate recognition of sadness negatively correlated with alexithymia traits. On the other hand, better ToM capabilities in male participants were associated with improvement in recognition of positive and neutral emotions. Finally, none of the observed age-related reductions in emotional recognition were related to amygdala and its subnuclei volumes. In contrast, both global volume of amygdala and its cortical and centromedial subnuclei had significant direct effects on recognition of sad images.

Furthering the language hypothesis of alexithymia: An integrated review and meta-analysis

Alexithymia, including the inability to identify and express one's own feelings, is a subclinical condition responsible for some of the socioemotional symptoms seen across a range of psychiatric conditions. The language hypothesis of alexithymia posits a language-mediated disruption in the development of discrete emotion concepts from ambiguous affective states, exacerbating the risk of developing alexithymia in language-impaired individuals. To provide a critical evaluation, a systematic review and meta-analysis of 29 empirical studies of language functioning in alexithymia was performed. A modest association was found between alexithymia and multi-domain language deficits (r = -0.14), including structural language, pragmatics, and propensity to use emotional language. A more theoretically-relevant subsample analysis comparing alexithymia levels in language-impaired and typical individuals revealed larger effects, but a limited number of studies adopted this approach. A synthesis of 11 emotional granularity studies also found an association between alexithymia and reduced emotional granularity (r = -0.10). Language impairments seem to increase the risk of alexithymia. Heterogeneous samples and methods suggest the need for studies with improved alexithymia assessments.

Beyond Face and Voice: A Review of Alexithymia and Emotion Perception in Music, Odor, Taste, and Touch

Alexithymia is a clinically relevant personality trait characterized by deficits in recognizing and verbalizing one's emotions. It has been shown that alexithymia is related to an impaired perception of external emotional stimuli, but previous research focused on emotion perception from faces and voices. Since sensory modalities represent rather distinct input channels it is important to know whether alexithymia also affects emotion perception in other modalities and expressive domains. The objective of our review was to summarize and systematically assess the literature on the impact of alexithymia on the perception of emotional (or hedonic) stimuli in music, odor, taste, and touch. Eleven relevant studies were identified. On the basis of the reviewed research, it can be preliminary concluded that alexithymia might be associated with deficits in the perception of primarily negative but also positive emotions in music and a reduced perception of aversive taste. The data available on olfaction and touch are inconsistent or ambiguous and do not allow to draw conclusions. Future investigations would benefit from a multimethod assessment of alexithymia and control of negative affect. Multimodal research seems necessary to advance our understanding of emotion perception deficits in alexithymia and clarify the contribution of modality-specific and supramodal processing impairments.