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Presaccadic EEG activity predicts visual saliency in free-viewing contour integration

While viewing a scene, the eyes are attracted to salient stimuli. We set out to identify the brain signals controlling this process. In a contour integration task, in which participants searched for a collinear contour in a field of randomly oriented Gabor elements, a previously established model was applied to calculate a visual saliency value for each fixation location. We studied brain activity

Multi-Electrode Alpha tACS During Varying Background Tasks Fails to Modulate Subsequent Alpha Power

Transcranial alternating-current stimulation (tACS) for entraining alpha activity holds potential for influencing mental function, both in laboratory and clinical settings. While initial results of alpha entrainment are promising, questions remain regarding its translational potential-namely if tACS alpha entrainment is sufficiently robust to context and to what extent it can be upscaled to multi-

EEG frequency tagging reveals higher order intermodulation components as neural markers of learned holistic shape representations

Shape perception is intrinsically holistic: combinations of features give rise to configurations with emergent properties that are different from the sum of the parts. The current study investigated neural markers of holistic shape representations learned by means of categorization training. We used the EEG frequency tagging technique, where two parts of a shape stimulus were 'tagged' by modifying

Large-Scale Traveling Waves in EEG Activity Following Eye Movement

In spontaneous, stimulus-evoked, and eye-movement evoked EEG, the oscillatory signal shows large scale, dynamically organized patterns of phase. We investigated eye-movement evoked patterns in free-viewing conditions. Participants viewed photographs of natural scenes in anticipation of a memory test. From 200 ms intervals following saccades, we estimated the EEG phase gradient over the entire scal

Task modulates functional connectivity networks in free viewing behavior

In free visual exploration, eye-movement is immediately followed by dynamic reconfiguration of brain functional connectivity. We studied the task-dependency of this process in a combined visual search-change detection experiment. Participants viewed two (nearly) same displays in succession. First time they had to find and remember multiple targets among distractors, so the ongoing task involved me

EEG frequency tagging dissociates between neural processing of motion synchrony and human quality of multiple point-light dancers

Do we perceive a group of dancers moving in synchrony differently from a group of drones flying in-sync? The brain has dedicated networks for perception of coherent motion and interacting human bodies. However, it is unclear to what extent the underlying neural mechanisms overlap. Here we delineate these mechanisms by independently manipulating the degree of motion synchrony and the humanoid quali

Intermittent regime of brain activity at the early, bias-guided stage of perceptual learning

Perceptual learning improves visual performance. Among the plausible mechanisms of learning, reduction of perceptual bias has been studied the least. Perceptual bias may compensate for lack of stimulus information, but excessive reliance on bias diminishes visual discriminability. We investigated the time course of bias in a perceptual grouping task and studied the associated cortical dynamics in

Combining EEG and eye movement recording in free viewing : Pitfalls and possibilities

Co-registration of EEG and eye movement has promise for investigating perceptual processes in free viewing conditions, provided certain methodological challenges can be addressed. Most of these arise from the self-paced character of eye movements in free viewing conditions. Successive eye movements occur within short time intervals. Their evoked activity is likely to distort the EEG signal during

Global Neuromagnetic Cortical Fields Have Non-Zero Velocity

Globally coherent patterns of phase can be obscured by analysis techniques that aggregate brain activity measures across-trials, whether prior to source localization or for estimating inter-areal coherence. We analyzed, at single-trial level, whole head MEG recorded during an observer-triggered apparent motion task. Episodes of globally coherent activity occurred in the delta, theta, alpha and bet

Fixation duration surpasses pupil size as a measure of memory load in free viewing

Oculomotor behavior reveals, not only the acquisition of visual information at fixation, but also the accumulation of information in memory across subsequent fixations. Two candidate measures were considered as indicators of such dynamic visual memory load: fixation duration and pupil size. While recording these measures, we displayed an arrangement of 3, 4 or 5 targets among distractors. Both occ

SMIM1 absence is associated with reduced energy expenditure and excess weight

BACKGROUND: Obesity rates have nearly tripled in the past 50 years, and by 2030 more than 1 billion individuals worldwide are projected to be obese. This creates a significant economic strain due to the associated non-communicable diseases. The root cause is an energy expenditure imbalance, owing to an interplay of lifestyle, environmental, and genetic factors. Obesity has a polygenic genetic arch

Spatial variation of ground level ozone and the relation between ozone and NO2/NOx in two Swedish cities

Background Ozone is a pollutant known to cause adverse effects on human health. It is formed by reactions between nitrogen oxides (NOx) and hydrocarbons under the influence of sunlight. In urban areas ozone is consumed oxidating nitrogen oxide (NO) to nitrogen dioxide (NO2). Despite the potential to cause adverse health effects, the local spatial distribution of ozone and the relationship between

Pain prevalence and pain relief in end-of-life care - a national registry study

BACKGROUND: Despite pain control being a top priority in end-of-life care, pain continues to be a troublesome symptom and comprehensive data on pain prevalence and pain relief in patients with different diagnoses are scarce.METHODS: The Swedish Register of Palliative Care (SRPC) was used to retrieve data from 2011 to 2022 about pain during the last week of life. Data were collected regarding occur

Differentiation of clinical characteristics, mortality, healthcare utilization and costs among four subgroups in a population with heart failure

Heart failure (HF) is associated with high mortality, decreased quality of life, and places a heavy burden on healthcare resources. Numerous HF patients are diagnosed without a conclusive echocardiogram and are lacking appropriate pharmacotherapy. The majority of HF studies in Sweden are based on hospital registries that may not represent the entirety of the HF patient population. This thesis exam

Health impact assessment of road traffic noise exposure – A case study of a pre- and post-densification scenario

BACKGROUND AND AIM: In many places worldwide there is an ongoing urbanization, often achieved through densification. An increased number of inhabitants in an area often leads to both increased traffic and placement of new buildings closer to roads, and thus increased population exposure to road traffic noise. The aim of the study was to estimate and compare the health impacts of road traffic noise