Blue Light Stimulates Cognitive Brain Activity in Visually Blind Individuals

Light regulates multiple non-image-forming (or nonvisual) circadian, neuroendocrine, and neurobehavioral functions, via outputs from intrinsically photosensitive retinal ganglion cells (ipRGCs). Exposure to light directly enhances alertness and performance, so light is an important regulator of wakefulness and cognition. The roles of rods, cones, and ipRGCs in the impact of light on cognitive brain functions remain unclear, however. A small percentage of blind individuals retain non-image-forming photoreception and offer a unique opportunity to investigate light impacts in the absence of conscious vision, presumably through ipRGCs. Here, we show that three such patients were able to choose nonrandomly about the presence of light despite their complete lack of sight. Furthermore, 2 sec of blue light modified EEG activity when administered simultaneously to auditory stimulations. fMRI further showed that, during an auditory working memory task, less than a minute of blue light triggered the recruitment of supplemental prefrontal and thalamic brain regions involved in alertness and cognition regulation as well as key areas of the default mode network. These results, which have to be considered as a proof of concept, show that non-image-forming photoreception triggers some awareness for light and can have a more rapid impact on human cognition than previously understood, if brain processing is actively engaged. Furthermore, light stimulates higher cognitive brain activity, independently of vision, and engages supplemental brain areas to perform an ongoing cognitive process. To our knowledge, our results constitute the first indication that ipRGC signaling may rapidly affect fundamental cerebral organization, so that it could potentially participate to the regulation of numerous aspects of human brain function.

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Light modulates oscillatory alpha activity in the occipital cortex of totally visually blind individuals with intact non-visual photoreception

10.1101/175851 ◽

2017 ◽

Author(s):

Gilles Vandewalle ◽

Markus J. van Ackeren ◽

Véronique Daneault ◽

Joseph T. Hull ◽

Geneviève Albouy ◽

...

Keyword(s):

Ganglion Cells ◽

Brain Activity ◽

Occipital Cortex ◽

Mammalian Brain ◽

Visual Responses ◽

Visual Functions ◽

Pupil Constriction ◽

Major Shift ◽

Blind Individuals ◽

The Impact

The discovery of intrinsically photosensitive retinal ganglion cells (ipRGCs) marked a major shift in our understanding of how light is processed by the mammalian brain. These ipRGCs influence multiple functions not directly related to vision such as the synchronization of circadian rhythmicity, pupil constriction, the regulation of alertness and sleep, as well as the modulation of cognition. More recently, it was demonstrated that ipRGCs may also contribute to basic visual functions. The impact of ipRGCs on visual functions, independently of image forming photoreceptors, remains however difficult to isolate, particularly in humans. We previously showed that exposure to intense monochromatic blue light (465nm) induced awareness of light in a forced choice task in three rare totally visually blind individuals without detectable rod and cone function, but who retained non-visual responses to light, very likely via ipRGCs. The neural foundation of such light awareness in the absence of conscious vision is unknown, however. In this study, we characterized the brain activity of these three rare participants using electroencephalography (EEG), and demonstrate that unconsciously perceived light triggers an early and reliable transient desynchronization (i.e. decreased power) of the alpha EEG rhythm (8-14 Hz) over the occipital cortex. These results provide compelling insight into how ipRGC may contribute to transient changes in ongoing brain activity. They suggest that occipital alpha rhythm synchrony, which is typically linked to the visual system, is modulated by ipRGCs photoreception; a process that may contribute to the awareness of light in those blind individuals.

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Brain Activity-Based Metrics for Assessing Learning States in VR under Stress among Firefighters: An Explorative Machine Learning Approach in Neuroergonomics

Brain Sciences ◽

10.3390/brainsci11070885 ◽

2021 ◽

Vol 11 (7) ◽

pp. 885

Author(s):

Maher Abujelala ◽

Rohith Karthikeyan ◽

Oshin Tyagi ◽

Jing Du ◽

Ranjana K. Mehta

Keyword(s):

Machine Learning ◽

Environmental Conditions ◽

Brain Activity ◽

Memory Task ◽

Classification Problem ◽

Brain Regions ◽

Training Data ◽

Information Encoding ◽

Machine Learning Approach ◽

Encoding And Retrieval

The nature of firefighters` duties requires them to work for long periods under unfavorable conditions. To perform their jobs effectively, they are required to endure long hours of extensive, stressful training. Creating such training environments is very expensive and it is difficult to guarantee trainees’ safety. In this study, firefighters are trained in a virtual environment that includes virtual perturbations such as fires, alarms, and smoke. The objective of this paper is to use machine learning methods to discern encoding and retrieval states in firefighters during a visuospatial episodic memory task and explore which regions of the brain provide suitable signals to solve this classification problem. Our results show that the Random Forest algorithm could be used to distinguish between information encoding and retrieval using features extracted from fNIRS data. Our algorithm achieved an F-1 score of 0.844 and an accuracy of 79.10% if the training and testing data are obtained at similar environmental conditions. However, the algorithm’s performance dropped to an F-1 score of 0.723 and accuracy of 60.61% when evaluated on data collected under different environmental conditions than the training data. We also found that if the training and evaluation data were recorded under the same environmental conditions, the RPM, LDLPFC, RDLPFC were the most relevant brain regions under non-stressful, stressful, and a mix of stressful and non-stressful conditions, respectively.

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Level of Automation Forms a Key Aspect of Autonomy Design

Journal of Cognitive Engineering and Decision Making ◽

10.1177/1555343417723432 ◽

2017 ◽

Vol 12 (1) ◽

pp. 29-34 ◽

Cited By ~ 17

Author(s):

Mica R. Endsley

Keyword(s):

Situation Awareness ◽

Interface Design ◽

Human Performance ◽

Human Cognition ◽

Level Of Automation ◽

Out Of The Loop ◽

Wide Range ◽

Levels Of Automation ◽

And Performance ◽

The Impact

The concept of different levels of automation (LOAs) has been pervasive in the automation literature since its introduction by Sheridan and Verplanck. LOA taxonomies have been very useful in guiding understanding of how automation affects human cognition and performance, with several practical and theoretical benefits. Over the past several decades a wide body of research has been conducted on the impact of various LOAs on human performance, workload, and situation awareness (SA). LOA has a significant effect on operator SA and level of engagement that helps to ameliorate out-of-the-loop performance problems. Together with other aspects of system design, including adaptive automation, granularity of control, and automation interface design, LOA is a fundamental design characteristic that determines the ability of operators to provide effective oversight and interaction with system autonomy. LOA research provides a solid foundation for guiding the creation of effective human–automation interaction, which is critical for the wide range of autonomous and semiautonomous systems currently being developed across many industries.

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The Effect of Performance-Based Incentive Contracts on System 1 and System 2 Processing in Affective Decision Contexts: fMRI and Behavioral Evidence

The Accounting Review ◽

10.2308/accr-50852 ◽

2014 ◽

Vol 89 (6) ◽

pp. 1979-2010 ◽

Cited By ~ 41

Author(s):

Anne M. Farrell ◽

Joshua O. Goh ◽

Brian J. White

Keyword(s):

Brain Activity ◽

Brain Regions ◽

Emotional Reactions ◽

Data Availability ◽

System 2 ◽

Fixed Wage ◽

Behavioral Evidence ◽

And Performance ◽

Performance Based Contracts ◽

System 1

ABSTRACT Managers may rely on emotional reactions to a setting to the detriment of economic considerations (“System 1 processing”), resulting in decisions that are costly for firms. While economic theory prescribes performance-based incentives to align goals and induce effort, psychology theory suggests that the salience of emotions is difficult to overcome without also inducing more deliberate consideration of both emotional and economic factors (“System 2 processing”). We link these perspectives by investigating whether performance-based incentives mitigate the costly influence of emotion by inducing more System 2 processing. Using functional magnetic resonance imaging and traditional experiments, we investigate managers' brain activity and choices under fixed wage and performance-based contracts. Under both, brain regions associated with System 1 processing are more active when emotion is present. Relative to fixed wage contracts, performance-based contracts induce System 2 processing in emotional contexts beyond that observed absent emotion, and decrease the proportion of economically costly choices. Data Availability: Contact the authors.

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Functional neuroimaging of psychiatric disorders: exploring hidden behaviour

Psychological Medicine ◽

10.1017/s0033291704002430 ◽

2004 ◽

Vol 34 (4) ◽

pp. 577-581 ◽

Cited By ~ 9

Author(s):

P. C. FLETCHER

Keyword(s):

Functional Neuroimaging ◽

Brain Activity ◽

Cognitive Strategies ◽

Healthy Person ◽

Brain Regions ◽

Task Demands ◽

Unrealistic Expectation ◽

Positron Emission ◽

The Impact ◽

Function Mapping

From the outset, people have had high expectations of functional neuroimaging. Many will have been disappointed. After roughly a decade of widespread use, even an enthusiastic advocate must be diffident about the impact of the two most frequently used techniques – positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) – upon clinical psychiatry. Perhaps this disappointment arises from an unrealistic expectation of what these techniques are able to tell us about the workings of the normal and the disordered brain. Anyone who hoped for intricate and unambiguous region-to-function mapping was always going to be disappointed. This expectation presupposes, among other things, a thorough understanding of the cognitive functions that are to be mapped onto the brain regions. This understanding, however, while developing, is still rudimentary. Mapping disorder along comparable lines is even more complex since it demands two levels of understanding. The first is of the healthy region-to-function mapping, the second of the disordered region-to-function mapping, which immediately demands a consideration of the nature of the function in the disordered state. After all, someone with schizophrenia, when confronted with a psychological task, might tackle it in a very different way, in terms of the cognitive strategies used, from a healthy person confronted with the same task. The observation that brain activity differs across the two individuals would only be interpretable insofar as one thoroughly understood the processes that each individual invoked in response to the task demands.

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Activity flow underlying abnormalities in brain activations and cognition in schizophrenia

Science Advances ◽

10.1126/sciadv.abf2513 ◽

2021 ◽

Vol 7 (29) ◽

pp. eabf2513

Author(s):

Luke J. Hearne ◽

Ravi D. Mill ◽

Brian P. Keane ◽

Grega Repovš ◽

Alan Anticevic ◽

...

Keyword(s):

Cognitive Dysfunction ◽

Large Scale ◽

Brain Activity ◽

Memory Task ◽

Clinical Intervention ◽

Brain Regions ◽

Imaging Data ◽

Flow Mapping ◽

Flow Models ◽

Evoked Activity

Cognitive dysfunction is a core feature of many brain disorders, including schizophrenia (SZ), and has been linked to aberrant brain activations. However, it is unclear how these activation abnormalities emerge. We propose that aberrant flow of brain activity across functional connectivity (FC) pathways leads to altered activations that produce cognitive dysfunction in SZ. We tested this hypothesis using activity flow mapping, an approach that models the movement of task-related activity between brain regions as a function of FC. Using functional magnetic resonance imaging data from SZ individuals and healthy controls during a working memory task, we found that activity flow models accurately predict aberrant cognitive activations across multiple brain networks. Within the same framework, we simulated a connectivity-based clinical intervention, predicting specific treatments that normalized brain activations and behavior in patients. Our results suggest that dysfunctional task-evoked activity flow is a large-scale network mechanism contributing to cognitive dysfunction in SZ.

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Data-driven models reveal the organization of diverse cognitive functions in the brain

10.1101/614081 ◽

2019 ◽

Author(s):

Tomoya Nakai ◽

Shinji Nishimoto

Keyword(s):

Cognitive Processes ◽

Brain Activity ◽

Quantitative Model ◽

Task Type ◽

Hierarchical Organization ◽

Human Cognition ◽

Cognitive Tasks ◽

Cortical Organization ◽

Brain Functions ◽

Complete Representations

AbstractOur daily life is realized by the complex orchestrations of diverse brain functions including perception, decision, and action. One of the central issues in cognitive neuroscience is to reveal the complete representations underlying such diverse functions. Recent studies have revealed representations of natural perceptual experiences using encoding models1–5. However, there has been little attempt to build a quantitative model describing the cortical organization of multiple active, cognitive processes. Here, we measured brain activity using functional MRI while subjects performed over 100 cognitive tasks, and examined cortical representations with two voxel-wise encoding models6. A sparse task-type encoding model revealed a hierarchical organization of cognitive tasks, their representation in cognitive space, and their mapping onto the cortex. A cognitive factor encoding model utilizing continuous intermediate features by using metadata-based inferences7 predicted brain activation patterns for more than 80 % of the cerebral cortex and decoded more than 95 % of tasks, even under novel task conditions. This study demonstrates the usability of quantitative models of natural cognitive processes and provides a framework for the comprehensive cortical organization of human cognition.

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Chronic Exposure to Hypoxia Inhibits Myelinogenesis and Causes Motor Coordination Deficits in Adult Mice

Neuroscience Bulletin ◽

10.1007/s12264-021-00745-1 ◽

2021 ◽

Author(s):

Lin Chen ◽

Shu-Yu Ren ◽

Rui-Xue Li ◽

Kun Liu ◽

Jing-Fei Chen ◽

...

Keyword(s):

Motor Coordination ◽

Chronic Hypoxia ◽

Brain Regions ◽

Functional Deficits ◽

Brain Functions ◽

Highly Active ◽

Adult Mice ◽

Functional Consequences ◽

Underlying Mechanisms ◽

The Impact

AbstractExposure to chronic hypoxia is considered to be a risk factor for deficits in brain function in adults, but the underlying mechanisms remain largely unknown. Since active myelinogenesis persists in the adult central nervous system, here we aimed to investigate the impact of chronic hypoxia on myelination and the related functional consequences in adult mice. Using a transgenic approach to label newly-generated myelin sheaths (NG2-CreERTM; Tau-mGFP), we found that myelinogenesis was highly active in most brain regions, such as the motor cortex and corpus callosum. After exposure to hypoxia (10% oxygen) 12 h per day for 4 weeks, myelinogenesis was largely inhibited in the 4-month old brain and the mice displayed motor coordination deficits revealed by the beam-walking test. To determine the relationship between the inhibited myelination and functional impairment, we induced oligodendroglia-specific deletion of the transcription factor Olig2 by tamoxifen (NG2-CreERTM; Tau-mGFP; Olig2 fl/fl) in adult mice to mimic the decreased myelinogenesis caused by hypoxia. The deletion of Olig2 inhibited myelinogenesis and consequently impaired motor coordination, suggesting that myelinogenesis is required for motor function in adult mice. To understand whether enhancing myelination could protect brain functions against hypoxia, we treated hypoxic mice with the myelination-enhancing drug-clemastine, which resulted in enhanced myelogenesis and improved motor coordination. Taken together, our data indicate that chronic hypoxia inhibits myelinogenesis and causes functional deficits in the brain and that enhancing myelinogenesis protects brain functions against hypoxia-related deficits.

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Neuroscience Research on Human Visual Path Integration: Empirical Overview and Strategic Considerations

10.31234/osf.io/h6u3b ◽

2021 ◽

Author(s):

Jimmy Y. Zhong

Keyword(s):

Path Integration ◽

Hippocampal Formation ◽

Brain Activity ◽

Brain Regions ◽

Neural Basis ◽

Age Related ◽

Neuroscience Research ◽

Integration Strategies ◽

The Impact ◽

The Brain

Over the past two decades, many neuroimaging studies have attempted uncover the brain regions and networks involved in path integration and identify the underlying neurocognitive mechanisms. Although these studies made inroads into the neural basis of path integration, they have yet to offer a full disclosure of the functional specialization of the brain regions supporting path integration. In this paper, I reviewed notable neuroscientific studies on visual path integration in humans, identified the commonalities and discrepancies in their findings, and incorporated fresh insights from recent path integration studies. Specifically, this paper presented neuroscientific studies performed with virtual renditions of the triangle/path completion task and addressed whether or not the hippocampus is necessary for human path integration. Based on studies that showed evidence supporting and negating the involvement of the hippocampal formation in path integration, this paper introduces the proposal that the use of different path integration strategies may determine the extent to which the hippocampus and entorhinal cortex are engaged during path integration. To this end, recent studies that investigated the impact of different path integration strategies on behavioral performance and functional brain activity were discussed. Methodological concerns were raised with feasible recommendations for improving the experimental design of future strategy-related path integration studies, which can cover cognitive neuroscience research on age-related differences in the role of the hippocampal formation in path integration and Bayesian modelling of the interaction between landmark and self-motion cues. The practical value of investigating different path integration strategies was also discussed briefly from a biomedical perspective.

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The Impact of Sports-Related Concussions on the Language System

Annals of Behavioral Neuroscience ◽

10.18314/abne.v1i1.1222 ◽

2018 ◽

Vol 1 (1) ◽

pp. 36-46

Author(s):

Patrick S Ledwidge

Keyword(s):

Brain Activity ◽

Brain Regions ◽

Functional Brain Imaging ◽

Long Term Effects ◽

Brain Potentials ◽

Language System ◽

Induced Changes ◽

The Impact ◽

Language Network

Sports-related Concussions (SRC) and their potential long-term effects are a growing concern among athletes and their families. Research utilizing functional brain imaging/recording techniques (e.g., fMRI, ERP) seeks to explain how neurocognitive brain activity changes in the days and years following SRC. Although language deficits are documented following non-sports related concussion there remains a striking lack of research on how SRCs may influence the language system and their supporting neural mechanisms. Neuroimaging findings, however, demonstrate that SRCs alter structural and functional pathways within the frontotemporal language network. Brain regions included in this network generate language-related event-related brain potentials (ERPs), including the N400 and P600. ERPs have been used to demonstrate long-term neurocognitive alterations associated with concussion and may also provide objective and robust markers of SRC-induced changes to the language system.

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