Basic emotions: Differences in time sequence and functional imaging with low resolution brain electrical tomography (LORETA)

The aim of the present study is to investigate the relationship between the time course of brain activation during the observation of pictures depic ting scenes associated with the four basic emotion of happiness, sadness, fear and disgust. Twenty-nin e right-handed volunteers (17 male, 12 female; mean age 24.6 years) took part in the study. To stu dy the time course of the affective processing the low resolution brain electromagnetic tomography (LORETA) has been used. Each emotional condition has shown specific activation patterns in different brain regions, changing over time. Our findings are in good agreement with other brain-ima ging studies (PET/fMRI) but with the advantage to investigate the temporal evolution of the emotional process in the millisecond range. The results showed that the time sequence of activa tions is different and characteristic for each emotion conditions

Aspects psychologiques et socioculturels des troubles du spectre autistique

Le but de la présente étude est de souligner le rôle des aspects psychologiques et socioculturels dans le développement des Troubles du Spectre Autistique (TSA) dans le but d'acquérir des données utiles pour préparer des interventions éducatives et sanitaires pour les enfants autistes. Une approche transculturelle a été adoptée, en comparant des groupes d'enfants italiens et cubains. 52 enfants (âgés de 4 à 11 ans) ont pris part à l'étude: 30 italiens (15 avec TSA et 15 contrôle) et 22 cubains (11 avec TSA et 11 contrôle). Des différences significatives ont été constatées entre les deux groupes culturels en termes de structure du réseau social des enfants et de comportements des parents par rapport à leurs enfants. Cependant, la relation d'attachement mère-enfant et le fonctionnement cognitif et émotionnel des participants de cette étude étaient indépendants de la culture. Les auteurs discutent dans les conclusions des possibles applications de leurs découvertes

Temporal and spatial neural dynamics in the perception of basic emotions from complex scenes

The different temporal dynamics of emotions are critical to understand their evolutionary role in the regulation of interactions with the surrounding environment. Here, we investigated the temporal dynamics underlying the perception of four basic emotions from complex scenes varying in valence and arousal (fear, disgust, happiness and sadness) with the millisecond time resolution of Electroencephalography (EEG). Event-related potentials were computed and each emotion showed a specific temporal profile, as revealed by distinct time segments of significant differences from the neutral scenes. Fear perception elicited significant activity at the earliest time segments, followed by disgust, happiness and sadness. Moreover, fear, disgust and happiness were characterized by two time segments of significant activity, whereas sadness showed only one long-latency time segment of activity. Multidimensional scaling was used to assess the correspondence between neural temporal dynamics and the subjective experience elicited by the four emotions in a subsequent behavioral task. We found a high coherence between these two classes of data, indicating that psychological categories defining emotions have a close correspondence at the brain level in terms of neural temporal dynamics. Finally, we localized the brain regions of time-dependent activity for each emotion and time segment with the low-resolution brain electromagnetic tomography. Fear and disgust showed widely distributed activations, predominantly in the right hemisphere. Happiness activated a number of areas mostly in the left hemisphere, whereas sadness showed a limited number of active areas at late latency. The present findings indicate that the neural signature of basic emotions can emerge as the byproduct of dynamic spatiotemporal brain networks as investigated with millisecond-range resolution, rather than in time-independent areas involved uniquely in the processing one specific emotion