Neural dynamics of attentional resource allocation in early visual cortex: emotional scenes produce competitive interactions.

Salient emotional visual cues receive prioritized processing in human visual cortex. To what extent emotional facilitation relies on preattentional stimulus processing preceding semantic analysis remains controversial. Making use of steady-state visual evoke potentials frequency-tagged to meaningful complex emotional scenes and their scrambled versions, presented in a 4-Hz rapid serial visual presentation fashion, the current study tested temporal dynamics of semantic and emotional cue processing.

Distinct patterns of spatial attentional modulation of steady-state visual evoked magnetic fields (SSVEFs) in subdivisions of the human early visual cortex.

In recent years, steady-state visual evoked potentials (SSVEPs) became an increasingly valuable tool to investigate neural dynamics of competitive attentional interactions and brain-computer interfaces. This is due to their good signal-to-noise ratio, allowing for single-trial analysis, and their ongoing oscillating nature that enables to analyze temporal dynamics of facilitation and suppression. Given the popularity of SSVEPs, it is surprising that only a few studies looked at the cortical sources of these responses.

Conditioned up and down modulations of short latency gamma band oscillations in visual cortex during fear learning in humans.

Over the course of evolution, the human brain has been shaped to prioritize cues that signal potential danger. Thereby, the brain does not only favor species-specific prepared stimulus sets such as snakes or spiders but can learn associations between new cues and aversive outcomes. One important mechanism to achieve this is associated with learning induced plasticity changes in sensory cortex that optimizes the representation of motivationally relevant sensory stimuli.

A Model of the Early Visual System Based on Parallel Spike-Sequence Detection, Showing Orientation Selectivity.

Since the first half of the twentieth century, numerous studies have been conducted on how the visual cortex encodes basic image features. One of the hallmarks of basic feature extraction is the phenomenon of orientation selectivity, of which the underlying neuronal-level computational mechanisms remain partially unclear despite being intensively investigated. In this work we present a reduced visual system model (RVSM) of the first level of scene analysis, involving the retina, the lateral geniculate nucleus and the primary visual cortex (V1), showing orientation selectivity.

Threat imminence modulates neural gain in attention and motor relevant brain circuits in humans.

Different levels of threat imminence elicit distinct computational strategies reflecting how the organism interacts with its environment in order to guarantee survival. Thereby, parasympathetically driven orienting and inhibition of on-going behavior in post-encounter situations and defense reactions in circa-strike conditions associated with sympathetically driven action preparation are typically observed across species. Here, we show that healthy humans are characterized by markedly variable individual orienting or defense response tendencies as indexed by differential heart rate (HR) changes during the passive viewing of unpleasant pictures.