Dissociable Neural Information Dynamics of Perceptual Integration and Differentiation during Bistable Perception.

At any given moment, we experience a perceptual scene as a single whole and yet we may distinguish a variety of objects within it. This phenomenon instantiates two properties of conscious perception: integration and differentiation. Integration is the property of experiencing a collection of objects as a unitary percept and differentiation is the property of experiencing these objects as distinct from each other. Here, we evaluated the neural information dynamics underlying integration and differentiation of perceptual contents during bistable perception. Participants listened to a sequence of tones (auditory bistable stimuli) experienced either as a single stream (perceptual integration) or as two parallel streams (perceptual differentiation) of sounds. We computed neurophysiological indices of information integration and information differentiation with electroencephalographic and intracranial recordings. When perceptual alternations were endogenously driven, the integrated percept was associated with an increase in neural information integration and a decrease in neural differentiation across frontoparietal regions, whereas the opposite pattern was observed for the differentiated percept. However, when perception was exogenously driven by a change in the sound stream (no bistability), neural oscillatory power distinguished between percepts but information measures did not. We demonstrate that perceptual integration and differentiation can be mapped to theoretically motivated neural information signatures, suggesting a direct relationship between phenomenology and neurophysiology.

Time to Face Language: Embodied Mechanisms Underpin the Inception of Face-Related Meanings in the Human Brain.

In construing meaning, the brain recruits multimodal (conceptual) systems and embodied (modality-specific) mechanisms. Yet, no consensus exists on how crucial the latter are for the inception of semantic distinctions. To address this issue, we combined electroencephalographic (EEG) and intracranial EEG (iEEG) to examine when nouns denoting facial body parts (FBPs) and nonFBPs are discriminated in face-processing and multimodal networks. First, FBP words increased N170 amplitude (a hallmark of early facial processing). Second, they triggered fast (~100 ms) activity boosts within the face-processing network, alongside later (~275 ms) effects in multimodal circuits. Third, iEEG recordings from face-processing hubs allowed decoding ~80% of items before 200 ms, while classification based on multimodal-network activity only surpassed ~70% after 250 ms. Finally, EEG and iEEG connectivity between both networks proved greater in early (0-200 ms) than later (200-400 ms) windows. Collectively, our findings indicate that, at least for some lexico-semantic categories, meaning is construed through fast reenactments of modality-specific experience.

Early detection of intentional harm in the human amygdala.

A decisive element of moral cognition is the detection of harm and its assessment as intentional or unintentional. Moral cognition engages brain networks supporting mentalizing, intentionality, empathic concern and evaluation. These networks rely on the amygdala as a critical hub, likely through frontotemporal connections indexing stimulus salience. We assessed inferences about perceived harm using a paradigm validated through functional magnetic resonance imaging, eye-tracking and electroencephalogram recordings. During the task, we measured local field potentials in three patients with depth electrodes (n = 115) placed in the amygdala and in several frontal, temporal, and parietal locations. Direct electrophysiological recordings demonstrate that intentional harm induces early activity in the amygdala (<200 ms), which--in turn--predicts intention attribution. The amygdala was the only site that systematically discriminated between critical conditions and predicted their classification of events as intentional. Moreover, connectivity analysis showed that intentional harm induced stronger frontotemporal information sharing at early stages. Results support the 'many roads' view of the amygdala and highlight its role in the rapid encoding of intention and salience--critical components of mentalizing and moral evaluation.

Auditory Feedback Differentially Modulates Behavioral and Neural Markers of Objective and Subjective Performance When Tapping to Your Heartbeat.

Interoception, the perception of our body internal signals, plays a key role in maintaining homeostasis and guiding our behavior. Sometimes, we become aware of our body signals and use them in planning and strategic thinking. Here, we show behavioral and neural dissociations between learning to follow one's own heartbeat and metacognitive awareness of one's performance, in a heartbeat-tapping task performed before and after auditory feedback. The electroencephalography amplitude of the heartbeat-evoked potential in interoceptive learners, that is, participants whose accuracy of tapping to their heartbeat improved after auditory feedback, was higher compared with non-learners. However, an increase in gamma phase synchrony (30-45 Hz) after the heartbeat auditory feedback was present only in those participants showing agreement between objective interoceptive performance and metacognitive awareness. Source localization in a group of participants and direct cortical recordings in a single patient identified a network hub for interoceptive learning in the insular cortex. In summary, interoceptive learning may be mediated by the right insular response to the heartbeat, whereas metacognitive awareness of learning may be mediated by widespread cortical synchronization patterns.

Consistent Gradient of Performance and Decoding of Stimulus Type and Valence From Local and Network Activity.

The individual differences approach focuses on the variation of behavioral and neural signatures across subjects. In this context, we searched for intracranial neural markers of performance in three individuals with distinct behavioral patterns (efficient, borderline, and inefficient) in a dual-valence task assessing facial and lexical emotion recognition. First, we performed a preliminary study to replicate well-established evoked responses in relevant brain regions. Then, we examined time series data and network connectivity, combined with multivariate pattern analyses and machine learning, to explore electrophysiological differences in resting-state versus task-related activity across subjects. Next, using the same methodological approach, we assessed the neural decoding of performance for different dimensions of the task. The classification of time series data mirrored the behavioral gradient across subjects for stimulus type but not for valence. However, network-based measures reflected the subjects' hierarchical profiles for both stimulus types and valence. Therefore, this measure serves as a sensitive marker for capturing distributed processes such as emotional valence discrimination, which relies on an extended set of regions. Network measures combined with classification methods may offer useful insights to study single subjects and understand inter-individual performance variability. Promisingly, this approach could eventually be extrapolated to other neuroscientific techniques.

An unaware agenda: interictal consciousness impairments in epileptic patients.

Consciousness impairments have been described as a cornerstone of epilepsy. Generalized seizures are usually characterized by a complete loss of consciousness, whereas focal seizures have more variable degrees of responsiveness. In addition to these impairments that occur during ictal episodes, alterations of consciousness have also been repeatedly observed between seizures (i.e. during interictal periods). In this opinion article, we review evidence supporting the novel hypothesis that epilepsy produces consciousness impairments which remain present interictally. Then, we discuss therapies aimed to reduce seizure frequency, which may modulate consciousness between epileptic seizures. We conclude with a consideration of relevant pathophysiological mechanisms. In particular, the thalamocortical network seems to be involved in both seizure generation and interictal consciousness impairments, which could inaugurate a promising translational agenda for epilepsy studies.

Attention, in and Out: Scalp-Level and Intracranial EEG Correlates of Interoception and Exteroception.

Interoception, the monitoring of visceral signals, is often presumed to engage attentional mechanisms specifically devoted to inner bodily sensing. In fact, most standardized interoceptive tasks require directing attention to internal signals. However, most studies in the field have failed to compare attentional modulations between internally- and externally-driven processes, thus probing blind to the specificity of the former. Here we address this issue through a multidimensional approach combining behavioral measures, analyses of event-related potentials and functional connectivity via high-density electroencephalography, and intracranial recordings. In Study 1, 50 healthy volunteers performed a heartbeat detection task as we recorded modulations of the heartbeat-evoked potential (HEP) in three conditions: exteroception, basal interoception (also termed interoceptive accuracy), and post-feedback interoception (sometimes called interoceptive learning). In Study 2, to evaluate whether key interoceptive areas (posterior insula, inferior frontal gyrus, amygdala, and somatosensory cortex) were differentially modulated by externally- and internally-driven processes, we analyzed human intracranial recordings with depth electrodes in these regions. This unique technique provides a very fine grained spatio-temporal resolution compared to other techniques, such as EEG or fMRI. We found that both interoceptive conditions in Study 1 yielded greater HEP amplitudes than the exteroceptive one. In addition, connectivity analysis showed that post-feedback interoception, relative to basal interoception, involved enhanced long-distance connections linking frontal and posterior regions. Moreover, results from Study 2 showed a differentiation between oscillations during basal interoception (broadband: 35-110 Hz) and exteroception (1-35 Hz) in the insula, the amygdala, the somatosensory cortex, and the inferior frontal gyrus. In sum, this work provides convergent evidence for the specificity and dynamics of attentional mechanisms involved in interoception.

Reconocimiento de emociones faciales en niños con trastorno por déficit de atención/hiperactividad / Facial emotion recognition in children with attention-deficit/hyperactivity disorder

INTRODUCCIÓN: En sujetos con trastorno por déficit de atención/hiperactividad (TDAH), se observan dificultades en las relaciones interpersonales que se atribuyen a una afectación en las habilidades de reconocimiento de emociones faciales. Los estudios realizados no siempre tuvieron presente la naturaleza del estímulo seleccionado en pediatría, lo cual es fundamental porque la familiaridad en los rostros, en cuanto a sus características fisonómicas, favorece el reconocimiento de las expresiones. OBJETIVO: Identificar el perfil de reconocimiento de emociones en sujetos pediátricos con TDAH, utilizando como estímulo fotos de niños y niñas. Sujetos y métodos: Estudio analítico de corte transversal de casos y controles. Se analizaron los resultados obtenidos de 54 participantes de 7-13 años divididos en dos grupos: 26 en el grupo control y 28 en el grupo con TDAH. Realizaron una evaluación con la escala de inteligencia de Wechsler para niños (WISC-V), el Conners Continuous Performance Test II (CPT-II) y el Child Affective Facial Expression set (CAFE). RESULTADOS: El grupo con TDAH mostró un rendimiento menor en el reconocimiento de emociones en general, con mayor dificultad en el reconocimiento de enojo, sorpresa y expresión neutral en particular. No se encontró una relación entre el reconocimiento de emociones y la edad, el sexo, el cociente intelectual total o las variables de atención del CPT-II. CONCLUSIONES: Los sujetos con TDAH presentan déficits en el reconocimiento de emociones, especialmente en el reconocimiento de enojo, sorpresa y expresión neutral, que podrían explicar las dificultades en la interacción y deberían tratarse dentro del marco terapéutico

INTRODUCTION: There are difficulties in relationships that are attributed to a commitment in facial emotions recognition skills in subjects with attention-deficit/hyperactivity disorder (ADHD). The studies carried out did not always take into account the nature of the stimulus selected in pediatrics, which is important because the familiarity in faces, in terms of their physiognomic characteristics, makes it easier the recognition of the expressions. AIM: To identify the profile of recognition of emotions in pediatric subjects with ADHD, using as a stimulus photos of boys and girls. Subjects and methods: Analytical cross-sectional study of cases and controls. We analyzed the results obtained from 54 participants between 7 and 13 years divided into two groups: 26 in control group and 28 in ADHD group. They conducted an assessment with the Wechsler Intelligence Scale for Children (WISC-V), Conners' Continuous Performance Test II (CPT-II), and Child Affective Facial Expression set (CAFE). RESULTS: The ADHD group showed a lower performance in recognition of emotions in general, with greater difficulty in the recognition of anger, surprise and neutral expression in particular. No relationship was found between the recognition of emotions and age, sex, total intelligence quotient or CPT-II care variables. CONCLUSIONS: The subjects with ADHD present deficits in the recognition of emotions, especially in the recognition of anger, surprise and neutral expression, which could explain the difficulties in the interaction and that should be treated within the therapeutic framework

Trastornos transitorios de la lectura asociados a descargas paroxísticas epileptiformes interictales en videocorticografía invasiva / Transient reading disorders associated with interictal epileptiform paroxysmal discharges in invasive videocorticography

Introducción. La epilepsia en la edad pediátrica se asocia frecuentemente a trastornos cognitivos. Distintos estudios correlacionaron la presencia de trastornos cognitivos transitorios con la presencia de descargas epilépticas interictales (DEI). Caso clínico. Mujer de 23 años, con epilepsia focal farmacorresistente evaluada con videoelectroencefalograma (video-EEG) invasivo en el contexto de cirugía de la epilepsia. Del video-EEG invasivo se seleccionaron 300 épocas de 10 s de duración, que se clasificaron en dos grupos. El grupo 1 evidenció DEI restringidas a la corteza del giro frontal medio, el giro temporal inferior y los giros occipitotemporales lateral y medial izquierdos (hemisferio dominante). En el grupo 2 se observaron DEI en el giro frontal superior y medio, el giro precentral y los giros temporales medio e inferior izquierdos. La paciente leyó el mismo texto durante las épocas seleccionadas. Se contabilizó el número de palabras leídas en cada época. Se evaluó la memoria de trabajo mediante la prueba de dígitos inversos. En el grupo 1, la media de palabras leídas fue de 10,2 (IC 95%: 10,04-10,35); en el grupo 2, de 2,3 (IC 95%: 2,12-2,27; t(146) = 94,55; p < 0,0001). En el grupo 1, la media de dígitos inversos fue de 4,05 (IC 95%: 3,81-4,30); en el grupo 2, de 2,67 (IC 95%: 2,48-2,86; t(33) = 10,34; p < 0,0001). Conclusión. El hallazgo permite inferir que la interferencia de las DEI en la corteza del giro frontal superior y medio, el giro precentral, y los giros temporales medio e inferior del hemisferio dominante provoca una disfunción de las redes neuronales implicadas en los mecanismos de la lectura

Introduction. Epilepsy in pediatric age are frequently associated with cognitive disorders. Different studies correlated the presence of transient cognitive disorders with the presence of interictal epileptiform discharges (IEDs). Case report. A 23-year-old woman with pharmacoresistant focal epilepsy was evaluated with invasive videoEEG in the context of epilepsy surgery. There were selected 300 periods of 10 seconds duration from the invasive videoEEG, which were classified into two groups. Group 1 showed IEDs restricted to the cortex of the middle frontal gyrus, inferior temporal gyrus, left lateral and medial occipitotemporal gyrus (dominant hemisphere). In group 2, IEDs was observed in the upper and middle frontal gyrus, precentral, the inferior and middle temporal left gyrus. The patient read the same text during the selected peirods. The number of words read in each period was counted. The working memory was evaluated by the inverse digit test. In group 1, the average number of words read was 10.2 (95% CI: 10.04-10.35); in group 2 it was 2.3 (95% CI: 2.12-2.27; t(146) = 94.55; p < 0.0001). In group 1, the average of inverse digits was 4.05 (95% CI: 3.81-4.30); in group 2 it was 2.67 (95% CI: 2.48-2.86; t(33) = 10.34; p < 0.0001). Conclusions. Our finding allows us to infer that the interference of IEDs in the cortex of the upper and middle frontal gyrus, precentral, middle and lower temporal gyrus of the dominant hemisphere, causes a dysfunction of neural networks involved in reading