Mental health stigma remains a major global problem associated with low self-esteem, social withdrawal, and poor health-seeking behavior in individuals. However, limited published evidence details these challenges in Liberia. Knowledge of public perceptions toward mental illness and key trends in the associations between knowledge of mental, neurological, and substance use disorders (MNSs) and stigma is crucial to designing evidence-based mental health policies and supporting service delivery.
View Article and Find Full Text PDFOlder adults exposed to enriched environments (EEs) maintain relatively higher levels of cognitive function, even in the face of compromised markers of brain health. Response speed (RS) is often used as a simple proxy to measure the preservation of global cognitive function in older adults. However, it is unknown which specific selection, decision, and/or motor processes provide the most specific indices of neurocognitive health.
View Article and Find Full Text PDFCOVID-19 forced third-level students to transition to online learning (OL). Many students encountered issues with OL, such as accessibility. However, the relationship between OL issues and mental health during this time remains poorly understood.
View Article and Find Full Text PDFObjectives: Lack of knowledge and discriminatory attitudes and behaviours towards individuals with mental disorders is a worldwide problem but may be particularly damaging for young people. This pilot study examined knowledge, attitudes and behaviours towards schizophrenia, bipolar disorder and autism within a large sample of adults in Ireland, a country with the youngest population in Europe, in order to better understand public views on these groups.
Methods: In a correlational, cross-sectional design, 307 adults in Ireland over the age of 18 completed a questionnaire over Google Forms examining knowledge, attitudes and behaviours towards schizophrenia, bipolar disorder and autism.
Current models of perceptual decision-making assume that choices are made after evidence in favor of an alternative accumulates to a given threshold. This process has recently been revealed in human EEG recordings, but an unresolved issue is how these neural mechanisms are modulated by competing, yet task-irrelevant, stimuli. In this study, we tested 20 healthy participants on a motion direction discrimination task.
View Article and Find Full Text PDFBackground: Economic cost estimates have the potential to provide a valuable alternative perspective on the COVID-19 burden. We estimate the premature mortality productivity costs associated with COVID-19 across Europe.
Methods: We calculated excess deaths between the date the cumulative total of COVID-19 deaths reached 10 in a country to 15th May 2020 for nine countries (Belgium, France, Germany, Italy, The Netherlands, Portugal, Spain, Sweden and Switzerland).
Animal neurophysiological studies have identified neural signals within dorsal frontoparietal areas that trace a perceptual decision by accumulating sensory evidence over time and trigger action upon reaching a threshold. Although analogous accumulation-to-bound signals are identifiable on extracranial human electroencephalography, their cortical origins remain unknown. Here neural metrics of human evidence accumulation, predictive of the speed of perceptual reports, were isolated using electroencephalography and related to dorsal frontoparietal network (dFPN) connectivity using diffusion and resting-state functional magnetic resonance imaging.
View Article and Find Full Text PDFThe computations and neural processes underpinning decision making have primarily been investigated using highly simplified tasks in which stimulus onsets cue observers to start accumulating choice-relevant information. Yet, in daily life we are rarely afforded the luxury of knowing precisely when choice-relevant information will appear. Here, we examined neural indices of decision formation while subjects discriminated subtle stimulus feature changes whose timing relative to stimulus onset ('foreperiod') was uncertain.
View Article and Find Full Text PDFRecent behavioral modeling and pupillometry studies suggest that neuromodulatory arousal systems play a role in regulating decision formation but neurophysiological support for these observations is lacking. We employed a randomized, double-blinded, placebo-controlled, crossover design to probe the impact of pharmacological enhancement of catecholamine levels on perceptual decision-making. Catecholamine levels were manipulated using the clinically relevant drugs methylphenidate and atomoxetine, and their effects were compared with those of citalopram and placebo.
View Article and Find Full Text PDFThe timing and accuracy of perceptual decision-making is exquisitely sensitive to fluctuations in arousal. Although extensive research has highlighted the role of various neural processing stages in forming decisions, our understanding of how arousal impacts these processes remains limited. Here we isolated electrophysiological signatures of decision-making alongside signals reflecting target selection, attentional engagement and motor output and examined their modulation as a function of tonic and phasic arousal, indexed by baseline and task-evoked pupil diameter, respectively.
View Article and Find Full Text PDFDespite their small size, microsaccades can impede stimulus detections if executed at inopportune times. Although it has been shown that microsaccades evoke both inhibitory and excitatory responses across different visual regions, their impact on the higher-level neural decision processes that bridge sensory responses to action selection has yet to be examined. Here, we show that when human observers monitor stimuli for subtle feature changes, the occurrence of microsaccades long after (up to 800 ms) change onset predicts slower reaction times and this is accounted for by momentary suppression of neural signals at each key stage of decision formation: visual evidence encoding, evidence accumulation, and motor preparation.
View Article and Find Full Text PDFObjective: Brain-computer interfaces (BCI) use measures of brain activity to convey a user's intent without the need for muscle movement. Hybrid designs, which use multiple measures of brain activity, have been shown to increase the accuracy of BCIs, including those based on EEG signals reflecting covert attention. Our study examined whether incorporating a measure of the P3 response improved the performance of a previously reported attention-based BCI design that incorporates measures of steady-state visual evoked potentials (SSVEP) and alpha band modulations.
View Article and Find Full Text PDFHealthy subjects tend to exhibit a bias of visual attention whereby left hemifield stimuli are processed more quickly and accurately than stimuli appearing in the right hemifield. It has long been held that this phenomenon arises from the dominant role of the right cerebral hemisphere in regulating attention. However, methods that would enable more precise understanding of the mechanisms underpinning visuospatial bias have remained elusive.
View Article and Find Full Text PDFBrain networks subserving alertness in humans interact with those for spatial attention orienting. We employed blue-enriched light to directly manipulate alertness in healthy volunteers. We show for the first time that prior exposure to higher, relative to lower, intensities of blue-enriched light speeds response times to left, but not right, hemifield visual stimuli, via an asymmetric effect on right-hemisphere parieto-occipital α-power.
View Article and Find Full Text PDFComputational and neurophysiological research has highlighted neural processes that accumulate sensory evidence for perceptual decisions. These processes have been studied in the context of highly simplified perceptual discrimination paradigms in which the physical evidence appears at times and locations that are either entirely predictable or exogenously cued (e.g.
View Article and Find Full Text PDFAnnu Int Conf IEEE Eng Med Biol Soc
July 2016
In recent years it has been shown to be possible to create a Brain Computer Interface (BCI) using non-invasive electroencephalographic (EEG) measurements of covert visual spatial attention. For example, that both Steady-State Visual Evoked Potentials (SSVEP) and parieto-occipital alpha band activity have been shown to be sensitive to covert attention and this has been exploited to provide simple communication control without the need for any physical movement. In this study, potential improvements in the speed and accuracy of such a BCI are investigated by exploring the possibility of incorporating a P300 task into an SSVEP covert attention paradigm.
View Article and Find Full Text PDFNeurologically healthy individuals typically exhibit a subtle bias towards the left visual field during spatial judgments, known as "pseudoneglect". However, it has yet to be reliably established if the direction and magnitude of this lateral bias varies along the vertical plane. Here, participants were required to distribute their attention equally across a checkerboard array spanning the entire visual field in order to detect transient targets that appeared at unpredictable locations.
View Article and Find Full Text PDFHealthy subjects typically exhibit a subtle bias of visuospatial attention favouring left space that is commonly termed 'pseudoneglect'. This bias is attenuated, or shifted rightwards, with decreasing alertness over time, consistent with theoretical models proposing that pseudoneglect is a result of the right hemisphere׳s dominance in regulating attention. Although this 'time-on-task effect' for spatial bias is observed when averaging across whole samples of healthy participants, Benwell, C.
View Article and Find Full Text PDFAuditory selective attention is the ability to enhance the processing of a single sound source, while simultaneously suppressing the processing of other competing sound sources. Recent research has addressed a long-running debate by showing that endogenous attention produces effects on obligatory sensory responses to continuous and competing auditory stimuli. However, until now, this result has only been shown under conditions where the competing stimuli differed in both their frequency characteristics and, importantly, their spatial location.
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