Dynamic modulation of the processing of unpredicted technical errors by the posterior cingulate and the default mode network.

The pervasive use of information technologies (IT) has tremendously benefited our daily lives. However, unpredicted technical breakdowns and errors can lead to the experience of stress, which has been termed technostress. It remains poorly understood how people dynamically respond to unpredicted system runtime errors occurring while interacting with the IT systems on a behavioral and neuronal level.

Vestibular and visual brain areas in the medial cortex of the human brain.

Self-motion perception involves an interaction between vestibular and visual brain regions. In the lateral brain, it includes the parietoinsular vestibular cortex and the posterior insular cortex. In the medial cortex, the cingulate sulcus visual (CSv) area is known to process visual-vestibular cues.

Evidence of target enhancement and distractor suppression in early visual areas.

Although the mechanisms of target enhancement and distractor suppression have been investigated along the visual processing hierarchy, there remains some unknown as to the role of perceptual load on the competition between different task-related information as attention deployment is manipulated. We present an fMRI spatial cueing paradigm, in which 32 participants had to attend to either a left or a right hemifield location and to indicate the orientation of the target Gabor that was presented simultaneously to a noise patch distractor. Critically, the target could appear at either the cued, valid location or at the uncued, invalid location; in the latter, the noise patch distractor appeared at the cued location.

Cortical Thickness Related to Compensatory Viewing Strategies in Patients With Macular Degeneration.

Retinal diseases like age-related macular degeneration (AMD) or hereditary juvenile macular dystrophies (JMD) lead to a loss of central vision. Many patients compensate for this loss with a pseudo fovea in the intact peripheral retina, the so-called "preferred retinal locus" (PRL). How extensive eccentric viewing associated with central vision loss (CVL) affects brain structures responsible for visual perception and visually guided eye movements remains unknown.

Structural Connectivity Patterns of Side Effects Induced by Subthalamic Deep Brain Stimulation for Parkinson's Disease.

Tractography based on diffusion-weighted magnetic resonance imaging (DWI) models the structural connectivity of the human brain. Deep brain stimulation (DBS) targeting the subthalamic nucleus is an effective treatment for advanced Parkinson's disease, but may induce adverse effects. This study investigated the relationship between structural connectivity patterns of DBS electrodes and stimulation-induced side effects.

Aging and central vision loss: Relationship between the cortical macro-structure and micro-structure.

Aging and central vision loss are associated with cortical atrophies, but little is known about the relationship between cortical thinning and the underlying cellular structure. We compared the macro- and micro-structure of the cortical gray and superficial white matter of 38 patients with juvenile (JMD) or age-related (AMD) macular degeneration and 38 healthy humans (19-84 years) by multimodal MRI including diffusion-tensor imaging (DTI). A factor analysis showed that cortical thickness, tissue-dependent measures, and DTI-based measures were sensitive to distinct components of brain structure.

Deep brain stimulation: Connectivity profile for bradykinesia alleviation.

Objective: Subthalamic deep brain stimulation may alleviate bradykinesia in Parkinson patients. Research suggests that this stimulation effect may be mediated by brain networks like the corticocerebellar loop. This study investigated the connectivity between stimulation sites and cortical and subcortical structures to identify connections for effective stimulation.

Microstructure of the superior temporal gyrus and hallucination proneness - a multi-compartment diffusion imaging study.

Previous studies reported that the volume of the left superior temporal gyrus (STG) is reduced in patients with schizophrenia and negatively correlated with hallucination severity. Moreover, diffusion-tensor imaging studies suggested a relationship between the brain microstructure in the STG of patients and auditory hallucinations. Hallucinations are also experienced in non-patient groups.

Neural bases of enhanced attentional control: Lessons from action video game players.

Objectives: The ability to resist distraction and focus on-task-relevant information while being responsive to changes in the environment is fundamental to goal-directed behavior. Such attentional control abilities are regulated by a constant interplay between previously characterized bottom-up and top-down attentional networks. Here we ask about the neural changes within these two attentional networks that may mediate enhanced attentional control.

White Matter Connectivity of the Visual-Vestibular Cortex Examined by Diffusion-Weighted Imaging.

The parieto-insular vestibular cortex (PIVC) and the posterior insular cortex (PIC) are key regions of the cortical vestibular network, both located in the midposterior section of the lateral sulcus. Little is known about the structural connectivity pattern of these areas. We used probabilistic fiber tracking based on diffusion-weighted magnetic resonance imaging (MRI) and compared the ipsilateral connectivity of PIVC and PIC.

Connectivity of the Cingulate Sulcus Visual Area (CSv) in the Human Cerebral Cortex.

The human cingulate sulcus visual area (CSv) responds selectively to visual and vestibular cues to self-motion. Although it is more selective for visual self-motion cues than any other brain region studied, it is not known whether CSv mediates perception of self-motion. An alternative hypothesis, based on its location, is that it provides sensory information to the motor system for use in guiding locomotion.

Label Distribution in Tissues of Wheat Seedlings Cultivated with Tritium-Labeled Leonardite Humic Acid.

Humic substances (HS) play important roles in the biotic-abiotic interactions of the root plant and soil contributing to plant adaptation to external environments. However, their mode of action on plants remains largely unknown. In this study the HS distribution in tissues of wheat seedlings was examined using tritium-labeled humic acid (HA) derived from leonardite (a variety of lignites) and microautoradiography (MAR).

Surface-Based Analyses of Anatomical Properties of the Visual Cortex in Macular Degeneration.

Introduction: Macular degeneration (MD) can cause a central visual field defect. In a previous study, we found volumetric reductions along the entire visual pathways of MD patients, possibly indicating degeneration of inactive neuronal tissue. This may have important implications.

Impact of spatial constraints during seed germination on the evolution of angiosperm cotyledons: a case study from tropical Hydatellaceae (Nymphaeales).

Premise Of The Study: A bipolar embryo with cotyledons is a characteristic feature that appeared early in the evolution of seed plants. Cotyledon number is an important character in angiosperm classification. We explore the links between functional aspects of seed germination and the number and location of the cotyledons, using as a model the early-divergent angiosperm family Hydatellaceae, in which seedlings are superficially monocot-like.

Combined diffusion-weighted and functional magnetic resonance imaging reveals a temporal-occipital network involved in auditory-visual object processing.

Functional magnetic resonance imaging (MRI) showed that the superior temporal and occipital cortex are involved in multisensory integration. Probabilistic fiber tracking based on diffusion-weighted MRI suggests that multisensory processing is supported by white matter connections between auditory cortex and the temporal and occipital lobe. Here, we present a combined functional MRI and probabilistic fiber tracking study that reveals multisensory processing mechanisms that remained undetected by either technique alone.

Nicotine facilitates memory consolidation in perceptual learning.

Perceptual learning is a special type of non-declarative learning that involves experience-dependent plasticity in sensory cortices. The cholinergic system is known to modulate declarative learning. In particular, reduced levels or efficacy of the neurotransmitter acetylcholine were found to facilitate declarative memory consolidation.

Spatial shifts of audio-visual interactions by perceptual learning are specific to the trained orientation and eye.

A large proportion of the human cortex is devoted to visual processing. Contrary to the traditional belief that multimodal integration takes place in multimodal processing areas separate from visual cortex, several studies have found that sounds may directly alter processing in visual brain areas. Furthermore, recent findings show that perceptual learning can change the perceptual mechanisms that relate auditory and visual senses.

Diffusion tensor imaging shows white matter tracts between human auditory and visual cortex.

Although it is known that sounds can affect visual perception, the neural correlates for crossmodal interactions are still disputed. Previous tracer studies in non-human primates revealed direct anatomical connections between auditory and visual brain areas. We examined the structural connectivity of the auditory cortex in normal humans by diffusion-weighted tensor magnetic resonance imaging and probabilistic tractography.

Multisensory perceptual learning reshapes both fast and slow mechanisms of crossmodal processing.

Previous research has shown that sounds facilitate perception of visual patterns appearing immediately after the sound but impair perception of patterns appearing after some delay. Here we examined the spatial gradient of the fast crossmodal facilitation effect and the slow inhibition effect in order to test whether they reflect separate mechanisms. We found that crossmodal facilitation is only observed at visual field locations overlapping with the sound, whereas crossmodal inhibition affects the whole hemifield.

3D surface perception from motion involves a temporal-parietal network.

Previous research has suggested that three-dimensional (3D) structure-from-motion (SFM) perception in humans involves several motion-sensitive occipital and parietal brain areas. By contrast, SFM perception in nonhuman primates seems to involve the temporal lobe including areas MT, MST and FST. The present functional magnetic resonance imaging study compared several motion-sensitive regions of interest including the superior temporal sulcus (STS) while human observers viewed horizontally moving dots that defined either a 3D corrugated surface or a 3D random volume.

Specificity of auditory-guided visual perceptual learning suggests crossmodal plasticity in early visual cortex.

Sounds modulate visual perception. Blind humans show altered brain activity in early visual cortex. However, it is still unclear whether crossmodal activity in visual cortex results from unspecific top-down feedback, a lack of visual input, or genuinely reflects crossmodal interactions at early sensory levels.

A motion illusion reveals mechanisms of perceptual stabilization.

Visual illusions are valuable tools for the scientific examination of the mechanisms underlying perception. In the peripheral drift illusion special drift patterns appear to move although they are static. During fixation small involuntary eye movements generate retinal image slips which need to be suppressed for stable perception.

Comparative ovule and megagametophyte development in Hydatellaceae and water lilies reveal a mosaic of features among the earliest angiosperms.

Background And Aims: The embryo sac, nucellus and integuments of the early-divergent angiosperms Hydatellaceae and other Nymphaeales are compared with those of other seed plants, in order to evaluate the evolutionary origin of these characters in the angiosperms.

Methods: Using light microscopy, ovule and embryo sac development are described in five (of 12) species of Trithuria, the sole genus of Hydatellaceae, and compared with those of Cabombaceae and Nymphaeaceae.

Key Results: The ovule of Trithuria is bitegmic and tenuinucellate, rather than bitegmic and crassinucellate as in most other Nymphaeales.