Early Preferential Responses to Fear Stimuli in Human Right Dorsal Visual Stream--A Meg Study.

Emotional expressions of others are salient biological stimuli that automatically capture attention and prepare us for action. We investigated the early cortical dynamics of automatic visual discrimination of fearful body expressions by monitoring cortical activity using magnetoencephalography. We show that right parietal cortex distinguishes between fearful and neutral bodies as early as 80-ms after stimulus onset, providing the first evidence for a fast emotion-attention-action link through human dorsal visual stream.

Different cortical dynamics in face and body perception: an MEG study.

Evidence from functional neuroimaging indicates that visual perception of human faces and bodies is carried out by distributed networks of face and body-sensitive areas in the occipito-temporal cortex. However, the dynamics of activity in these areas, needed to understand their respective functional roles, are still largely unknown. We monitored brain activity with millisecond time resolution by recording magnetoencephalographic (MEG) responses while participants viewed photographs of faces, bodies, and control stimuli.

Standing up for the body. Recent progress in uncovering the networks involved in the perception of bodies and bodily expressions.

Recent studies of monkeys and humans have identified several brain regions that respond to bodies. Researchers have so far mainly addressed the same questions about bodies and bodily expressions that are already familiar from three decades of face and facial expression studies. Our present goal is to review behavioral, electrophysiological and neurofunctional studies on whole body and bodily expression perception against the background of what is known about face perception.

Thalamic lesions in a genetic rat model of absence epilepsy: dissociation between spike-wave discharges and sleep spindles.

Recent findings have challenged the traditional view that the thalamus is the primary driving source of generalized spike-wave discharges (SWDs) characteristic for absence seizures, and indicate a leading role for the cortex instead. In light of this we investigated the effects of thalamic lesions on SWDs and sleep spindles in the WAG/Rij rat, a genetic model of absence epilepsy. EEG was recorded from neocortex and thalamus in freely moving rats, both before and after unilateral thalamic ibotenic acid lesions.

Early category-specific cortical activation revealed by visual stimulus inversion.

Visual categorization may already start within the first 100-ms after stimulus onset, in contrast with the long-held view that during this early stage all complex stimuli are processed equally and that category-specific cortical activation occurs only at later stages. The neural basis of this proposed early stage of high-level analysis is however poorly understood. To address this question we used magnetoencephalography and anatomically-constrained distributed source modeling to monitor brain activity with millisecond-resolution while subjects performed an orientation task on the upright and upside-down presented images of three different stimulus categories: faces, houses and bodies.

Beyond the face: exploring rapid influences of context on face processing.

Humans optimize behavior by deriving context-based expectations. Contextual data that are important for survival are extracted rapidly, using coarse information, adaptive decision strategies, and dedicated neural infrastructure. In the field of object perception, the influence of a surrounding context has been a major research theme, and it has generated a large literature.

Rapid perceptual integration of facial expression and emotional body language.

In our natural world, a face is usually encountered not as an isolated object but as an integrated part of a whole body. The face and the body both normally contribute in conveying the emotional state of the individual. Here we show that observers judging a facial expression are strongly influenced by emotional body language.

Cortical focus drives widespread corticothalamic networks during spontaneous absence seizures in rats.

Absence seizures are the most pure form of generalized epilepsy. They are characterized in the electroencephalogram by widespread bilaterally synchronous spike-wave discharges (SWDs), which are the reflections of highly synchronized oscillations in thalamocortical networks. To reveal network mechanisms responsible for the initiation and generalization of the discharges, we studied the interrelationships between multisite cortical and thalamic field potentials recorded during spontaneous SWDs in the freely moving WAG/Rij rat, a genetic model of absence epilepsy.