Summary In this study, a representative group of Mongolian adults was tested for hepatitis B virus ( HBV ) and hepatitis C virus ( HCV ). Screening was conducted at 17 different locations on a randomly sampled group, representing the Mongolian adult population. A total of 1158 adults, 500 (43.1%) men and 659 (56.9%) women were included. The prevalence estimates of HBV and HCV amongst the general Mongolian adult population were found to be 11.1%±1% ( SE ) and 8.5%±0.7% or 207 418 and 160 228 cases, respectively. For HCV , the majority of cases are concentrated in older age groups with a prevalence of 25.8% amongst those aged 50 years and above, whilst the prevalence of HBV does not vary significantly amongst age groups. For both, HBV and HCV , the data indicate a higher risk of infection and a higher mortality because of the hepatitis amongst men than amongst women. This study represents the first nationwide estimate of the prevalence of HBV in Mongolia and also considered the first for HCV since 2005 and confirm the position of Mongolia as one of the hot‐spots of chronic hepatitis infection in the world with about 19.4% of the adult population being infected with either HBV or HCV .

In 2007 Kutzbach and colleagues published an interesting finding: they had found a markedly higher rate of attention-deficit hyperactivity disorder (ADHD) among children and adults with albinism in comparison to the general population. In a study of 75 children and 44 adults with albinism, the authors identified 17 children and 3 adults as having ADHD. This indicates a prevalence rate of 22.7% in the children and 6.8% in the adults in this population— a 1.9to 5.5-fold and a 1.5-fold increase when compared to the 4% to 12% and 4.4% prevalence rates in the general school-aged and adult population, respectively. Screening for ADHD symptoms was conducted using standard diagnostic practice. The authors did not find any relationship between presence of ADHD and type of albinism or visual acuity, which is nearly always severely impaired in persons with albinism. Kutzbach et al concluded that ADHD might represent an ‘‘additional abnormality of the central nervous system neuronal circuitry in albinism.’’ In this correspondence, we wish to point out why an ‘‘additional abnormality of the CNS neuronal circuitry in albinism’’ is unlikely to be present and that the most probable cause of the inattentive/hyperactive behavior in the children and adults studied is not ADHD. ADHD is a childhood behavioral disorder that is characterized by symptoms of inattention and hyperactivity/impulsivity that are inappropriate for the child’s developmental level and cause impairment of the child’s ability to function within his/ her environment. Evidence suggests that ADHD is an inherited neurological disorder, involving dysregulation of the catecholamine neurotransmitter system and frontal-subcortical circuits. A wealth of evidence also suggests that children with ADHD display significant neuropsychological deficits, particularly in relation to the executive functions. Despite evidence for neurologic dysfunction and neuropsychological impairment in ADHD, there is as yet no definitive biologic, neurologic, or neuropsychological test to identify ADHD. Diagnosis of ADHD rests solely upon identification of behavioral symptoms. For example, according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (which was used by Kutzbach and colleagues and which uses diagnostic criteria very similar to those employed in the current Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition), children must display at least 6 of 9 symptoms of inattention and at least 6 of 9 symptoms of hyperactivity/impulsivity in order to be diagnosed with ADHD Combined Type. The practice of diagnosing ADHD using behavioral criteria has long been recognized as being problematic. The reason for this is that symptoms of inattention and hyperactivity can occur for a variety of reasons other than what can be referred to as ‘‘true ADHD’’ or a genetic condition involving dysfunction of frontal-subcortical circuits and neurotransmitter function. For example, in one review of the causes of symptoms of inattention and hyperactivity, 38 possible causes of such symptoms were identified, including low self-esteem, frustration, anxiety, difficulties with psychosocial relationships, educational deficits, immature language development, and food allergies. Attention and behavior difficulties are ubiquitous in clinical practice, with many children with other disorders often displaying inattentive and hyperactive/impulsive symptoms. Because diagnosis of ADHD rests solely on behavioral criteria, it is very difficult to tell whether a child displaying inattentive and hyperactive/impulsive behavior has ‘‘true ADHD’’ or is displaying this behavior due to another underlying condition or difficulty coping with some factor in his/her life or environment. Kutzbach and colleagues’ findings may be a case in point. Although we do not doubt that the children with albinism in this study displayed significantly higher levels of inattentive and hyperactive behavior, we query whether these behaviors are indicative of an increased prevalence of ADHD among persons with albinism. Albinism is a condition that brings with it its own stresses. Although these are thus far poorly documented in the scientific literature, numerous accounts on online media describe the difficulties that persons with albinism face in terms of living with a different physical appearance, which can lead to difficulty integrating with their peers, and in coping with significantly reduced visual acuity. Given that inattentive and hyperactive behavior can arise for a variety of causes other than ADHD, it is possible that children with albinism display such symptoms because of the pressures of living with albinism. It appears more parsimonious to consider such potential causes before concluding in favor of an increased prevalence of ADHD among these children. Kutzbach et al seem to base their assumption that a difference of the central nervous system neural circuitry exists in

Objectives: Past research has largely neglected to investigate mild adverse effects (MAEs) to transcranial magnetic stimulation (TMS), including headache and nausea. Here we explored the relationship between MAEs, participant characteristics (age and gender) and protocol parameters, including mode of application, coil geometry, stimulated brain region, TMS frequency, TMS intensity, and active vs. sham stimulation.Methods: Data from 1270 standard post-monitoring forms was obtained from 113 healthy participants. Analyses aimed to identify the risk factors associated with MAE reports and specific symptoms.Results: The overall rate of MAEs across TMS sessions was similar to 5%, with similar to 78% of symptoms occurring post-session. Initial TMS sessions were followed by a higher MAE incidence rate relative to later testing sessions. No associations between participant characteristics, TMS frequency, or intensity were observed.Conclusions: TMS-related MAEs are relatively common and may be exacerbated by initial expectations or anxieties of participants. A significant proportion of MAEs may reflect reporting of coincidental phenomena that are unrelated to TMS. Recommendations for future safety studies are proposed and monitoring documentation is provided. Significance: Our findings illustrate the importance of standardized monitoring of MAEs. Such research aids our understanding of how MAEs arise and may lead to interventions for reducing their incidence. (C) 2012 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

In humans, each hemisphere comprises an overlay of two visuotopic maps of the contralateral visual field, one from each eye. Is the capacity of the visual cortex limited to these two maps or are plastic mechanisms available to host more maps? We determined the cortical organization of the visual field maps in a rare individual with chiasma hypoplasia, where visual cortex plasticity is challenged to accommodate three hemifield maps. Using high-resolution fMRI at 7T and diffusion-weighted MRI at 3T, we found three hemiretinal inputs, instead of the normal two, to converge onto the left hemisphere. fMRI-based population receptive field mapping of the left V1–V3 at 3T revealed three superimposed hemifield representations in the left visual cortex, i.e. two representations of opposing visual hemifields from the left eye and one right hemifield representation from the right eye. We conclude that developmental plasticity including the re-wiring of local intra- and cortico-cortical connections is pivotal to support the coexistence and functioning of three hemifield maps within one hemisphere.

In the past decade neuroscience has witnessed major advances in the field of multisensory interactions. A large body of research has revealed several new types of cross-sensory interactions. In addition, multisensory interactions have been reported at temporal and spatial system levels previously thought of as strictly unimodal. We review the findings that have led to the current broad consensus that most, if not all, higher, as well as lower level neural processes are in some form multisensory. We continue by outlining the progress that has been made in identifying the functional significance of different types of interactions, for example, in subserving stimulus binding and enhancement of perceptual certainty. Finally, we provide a critical introduction to cutting edge methods from bayes optimal integration to multivoxel pattern analysis as applied to multisensory research at different system levels.

Perception and response selection are core processes in the generation of overt behavior. Selective attention is known to facilitate behavioral performance by altering perceptual processes. It remains unclear, however, whether selective attention can aid the resolution of response conflict, and if so, at what stage of processing this takes place. In two experiments, an endogenous cuing task was combined with a flanker task to assess the interaction of selective attention with response selection. The results of Experiment 1 show that cuing reduces the flanker-congruency effect when the cue and flanker are presented in close temporal proximity to each other. The results of Experiment 2 demonstrate that pre- but not post-cuing the target reduced the congruency effect, showing that selective attention can affect performance, but is ineffective once stimulus processing has proceeded to response selection. Our results provide evidence that selective attention can aid the resolution of response conflict by altering early perceptual processing stages.

Presenting visual stimuli in physical 3D space during fMRI experiments carries significant technical challenges. Certain types of multisensory visuotactile experiments and visuomotor tasks require presentation of visual stimuli in peripersonal space, which cannot be accommodated by ordinary projection screens or binocular goggles. However, light points produced by a group of LEDs can be transmitted through fibre-optic cables and positioned anywhere inside the MRI scanner. Here we describe the design and implementation of a microcontroller-based programmable digital device for controlling fibre-optically transmitted LED lights from a PC. The main feature of this device is the ability to independently control the colour, brightness, and timing of each LED. Moreover, the device was designed in a modular and extensible way, which enables easy adaptation for various experimental paradigms. The device was tested and RI compatible devices validated in three fMRI experiments involving basic visual perception, a simple colour discrimination task, and a blocked multisensory visuo-tactile task. The results revealed significant lateralized activation in occipital cortex of all participants, a reliable response in ventral occipital areas to colour stimuli elicited by the device, and strong activations in multisensory brain regions in the multisensory task. Overall, these findings confirm the suitability of this device for presenting complex fibre-optic visual and cross-modal stimuli inside the scanner.

Presenting visual stimuli in physical 3D space during fMRI experiments carries significant technical challenges. Certain types of multisensory visuotactile experiments and visuomotor tasks require presentation of visual stimuli in peripersonal space, which cannot be accommodated by ordinary projection screens or binocular goggles. However, light points produced by a group of LEDs can be transmitted through fibre-optic cables and positioned anywhere inside the MRI scanner. Here we describe the design and implementation of a microcontroller-based programmable digital device for controlling fibre-optically transmitted LED lights from a PC. The main feature of this device is the ability to independently control the colour, brightness, and timing of each LED. Moreover, the device was designed in a modular and extensible way, which enables easy adaptation for various experimental paradigms. The device was tested and validated in three fMRI experiments involving basic visual perception, a simple colour discrimination task, and a blocked multisensory visuo-tactile task. The results revealed significant lateralized activation in occipital cortex of all participants, a reliable response in ventral occipital areas to colour stimuli elicited by the device, and strong activations in multisensory brain regions in the multisensory task. Overall, these findings confirm the suitability of this device for presenting complex fibre-optic visual and cross-modal stimuli inside the scanner.

Attentional interference between tasks performed in parallel is known to have strong and often undesired effects. As yet, however, the mechanisms by which interference operates remain elusive. A better knowledge of these processes may facilitate our understanding of the effects of attention on human performance and the debilitating consequences that disruptions to attention can have. According to the load theory of cognitive control, processing of task-irrelevant stimuli is increased by attending in parallel to a relevant task with high cognitive demands. This is due to the relevant task engaging cognitive control resources that are, hence, unavailable to inhibit the processing of task-irrelevant stimuli. However, it has also been demonstrated that a variety of types of load (perceptual and emotional) can result in a reduction of the processing of task-irrelevant stimuli, suggesting a uniform effect of increased load irrespective of the type of load. In the present study, we concurrently presented a relevant auditory matching task [n-back working memory (WM)] of low or high cognitive load (1-back or 2-back WM) and task-irrelevant images at one of three object visibility levels (0%, 50%, or 100%). fMRI activation during the processing of the task-irrelevant visual stimuli was measured in the lateral occipital cortex and found to be reduced under high, compared to low, WM load. In combination with previous findings, this result is suggestive of a more generalized load theory, whereby cognitive load, as well as other types of load (e.g., perceptual), can result in a reduction of the processing of task-irrelevant stimuli, in line with a uniform effect of increased load irrespective of the type of load.

According to perceptual load theory, processing of task-irrelevant stimuli is limited by the perceptual load of a parallel attended task if both the task and the irrelevant stimuli are presented to the same sensory modality. However, it remains a matter of debate whether the same principles apply to cross-sensory perceptual load and, more generally, what form cross-sensory attentional modulation in early perceptual areas takes in humans. Here we addressed these questions using functional magnetic resonance imaging. Participants undertook an auditory one-back working memory task of low or high perceptual load, while concurrently viewing task-irrelevant images at one of three object visibility levels. The processing of the visual and auditory stimuli was measured in the lateral occipital cortex (LOC) and auditory cortex (AC), respectively. Cross-sensory interference with sensory processing was observed in both the LOC and AC, in accordance with previous results of unisensory perceptual load studies. The present neuroimaging results therefore warrant the extension of perceptual load theory from a unisensory to a cross-sensory context: a validation of this cross-sensory interference effect through behavioural measures would consolidate the findings.

The investigation of imitation, which consists of observation and later reproduction of voluntary actions, promises insights into the complex processes of human actions. Although several aspects concerning the component neural processes necessary for action execution are known, our current understanding of the neural networks underlying these remains sparse. The present study applies independent component analysis (ICA) to functional magnetic resonance imaging (fMRI) data acquired during imitation of abstract gestures and object-related actions. This enables identification of neural networks underlying the production of these imitations. The explorative approach of ICA is complemented by an analysis of time courses from the maxima of each component. Four independent networks were active during delayed imitation. These can be assigned to the aspects of (1) action perception, (2) motor preparation and action execution, (3) encoding and retrieval into and from working memory, as well as (4) the dynamic integration of object affordances into the action. At least two of these networks participate in action preparation, one contains areas involved with motor working memory and one includes areas which are connected to the true action execution. The fourth network only shows activity shortly before an object-related action is imitated. This indicates a late integration of object affordances into the movement as the time course of activity in this network pertains to action rather than perception of the object.

Background Existing brain imaging studies, investigating sexual arousal via the presentation of erotic pictures or film excerpts, have mainly used blocked designs with long stimulus presentation times. Methods To clarify how experimental functional magnetic resonance imaging (fMRI) design affects stimulus-induced brain activity, we compared brief event-related presentation of erotic vs. neutral stimuli with blocked presentation in 10 male volunteers. Results Brain activation differed depending on design type in only 10% of the voxels showing task related brain activity. Differences between blocked and event-related stimulus presentation were found in occipitotemporal and temporal regions (Brodmann Area (BA) 19, 37, 48), parietal areas (BA 7, 40) and areas in the frontal lobe (BA 6, 44). Conclusion Our results suggest that event-related designs might be a potential alternative when the core interest is the detection of networks associated with immediate processing of erotic stimuli. Additionally, blocked, compared to event-related, stimulus presentation allows the emergence and detection of non-specific secondary processes, such as sustained attention, motor imagery and inhibition of sexual arousal.