scholarly journals Learning to see in 3D with two eyes: the role of experience, plasticity and neurochemistry

2020 ◽  
Vol 42 (5) ◽  
pp. 12-17
Author(s):  
Betina Ip ◽  
Holly Bridge
Keyword(s):  
Cerebral Cortex ◽  
Binocular Vision ◽  
Early Experience ◽  
Fine Tuning ◽  
Computational Power ◽  
The World ◽  
Accurate Performance ◽  
The Brain ◽  
Binocular Depth

Humans, along with other predators, have forward-facing eyes which restrict the area of the world that can be seen when compared to animals with eyes on the side of the head. Why would we sacrifice this panoramic vision? The answer is the very precise ability that having two eyes with overlapping and slightly different viewpoints provides to determine fine differences in depth. While interpreting this type of ‘binocular depth’ appears effortless, the precise calculations necessary for perceiving binocular depth require significant computational power in the cerebral cortex and the fine tuning of neurochemical interactions. This processing occurs in the visual regions of the brain and must be honed through early experience for accurate performance. By considering each stage of binocular processing and the neurochemical interactions required for integrating signals from the two eyes, we can begin to understand how the inherent ability of the brain to learn might help us when binocular vision goes wrong.

The role of the brain

2017 ◽  
Author(s):  
Ray Guillery
Keyword(s):  
Nervous System ◽  
Cerebral Cortex ◽  
Clinical Condition ◽  
The Other ◽  
Neural Pathways ◽  
Sense Organs ◽  
The World ◽  
Motor Actions ◽  
The Brain

This chapter introduces two interpretations of how we know about the world. One, the standard, sensory-to-motor view, is that physical actions for sounds, lights, tastes, smells, and so on act on our sense organs to produce messages that are sent through the nervous system to the cerebral cortex, where the relevant structures of the world can be recognized and appropriate motor actions can be initiated. The other is an interactive sensorimotor view where the nervous system records our interactions with the world, abstracting our knowledge about the world from these interactions. These two opposing views have rarely been considered in terms of specific neural pathways or the messages that they carry; that is the plan for this book. Each view leads to different sets of interpretations of experiments and to different sets of research proposals. The final part of the chapter explores a well-studied and widely taught clinical condition that illustrates the confusions that can arise when the dual meaning of the driver messages to the thalamus is not recognized.

scholarly journals Imaging Implicit Morphological Processing: Evidence from Hebrew

2010 ◽  
Vol 22 (9) ◽  
pp. 1955-1969 ◽  
Author(s):  
Atira S. Bick ◽  
Ram Frost ◽  
Gadi Goelman
Keyword(s):  
Masked Priming ◽  
Statistical Correlation ◽  
Morphological Processing ◽  
Fine Tuning ◽  
Semantic Transparency ◽  
Lexical Structure ◽  
The Neural Networks ◽  
Distinct Aspect ◽  
The Brain

Is morphology a discrete and independent element of lexical structure or does it simply reflect a fine-tuning of the system to the statistical correlation that exists among orthographic and semantic properties of words? Hebrew provides a unique opportunity to examine morphological processing in the brain because of its rich morphological system. In an fMRI masked priming experiment, we investigated the neural networks involved in implicit morphological processing in Hebrew. In the lMFG and lIFG, activation was found to be significantly reduced when the primes were morphologically related to the targets. This effect was not influenced by the semantic transparency of the morphological prime, and was not found in the semantic or orthographic condition. Additional morphologically related decrease in activation was found in the lIPL, where activation was significantly modulated by semantic transparency. Our findings regarding implicit morphological processing suggest that morphology is an automatic and distinct aspect of visually processing words. These results also coincide with the behavioral data previously obtained demonstrating the central role of morphological processing in reading Hebrew.

COVID-19 Beyond the Lungs

2022 ◽  
pp. 109-126
Author(s):  
Omar El Hiba ◽  
Hicham Chatoui ◽  
Nadia Zouhairi ◽  
Lahoucine Bahi ◽  
Lhoussaine Ammouta ◽  
...  
Keyword(s):  
Experimental Data ◽  
Nervous System ◽  
Clinical Symptoms ◽  
Case Reports ◽  
The World ◽  
Acute Pneumonia ◽  
The Brain ◽  
Cardinal Feature ◽  
Shed Light

Since December 2019, the world has been shaken by the spread of a highly pathogen virus, causing severe acute respiratory syndrome (SARS-Cov2), which emerged in Wuhan, China. SARS-Cov2 is known to cause acute pneumonia: the cardinal feature of coronavirus disease 2019 (COVID-19). Clinical features of the disease include respiratory distress, loss of spontaneous breathing, and sometimes neurologic signs such as headache and nausea and anosmia, leading to suppose a possible involvement of the nervous system as a potential target of SARS-CoV2. The chapter will shed light on the recent clinical and experimental data sustaining the involvement of the nervous system in the pathophysiology of COVID-19, based on several case reports and experimental data reporting the possible transmission of SARS-CoV2 throughout the peripheral nerves to the brain cardiorespiratory centers. Thus, understanding the role of the nervous system in the course of clinical symptoms of COVID-19 is important in determining the appropriate therapeutic approach to combat the disease.

Understanding as Living

2019 ◽  
pp. 7-53
Author(s):  
James W. Jones
Keyword(s):  
Sensory Experience ◽  
Laboratory Research ◽  
Interactive System ◽  
The World ◽  
Human Understanding ◽  
Research Findings ◽  
Network Studies ◽  
The Brain ◽  
Religious Understanding

Drawing upon clinical psychoanalysis and laboratory research, this chapter develops an “embodied-relational” epistemology. The chapter reviews major research findings on the ways embodiment influences the cognitive processes by which we understand ourselves and the world. It also reviews current neuro-network studies whose findings imply the brain can be understood as a single, interactive system and not simply a collection of relatively autonomous domains. The emphasis here is on the brain’s complexity, integration, and a certain degree of openness. Sensory experience is understood as an active, not passive process, involving an intimate interconnection between self and world. The role of proprioception, as well as the five basic senses, is analyzed. The implications of such research findings for human understanding, and especially religious understanding, are elaborated.

scholarly journals Human Development XI: The Structure of the Cerebral Cortex. Are There Really Modules in the Brain?

2007 ◽  
Vol 7 ◽  
pp. 1922-1929 ◽  
Author(s):  
Tyge Dahl Hermansen ◽  
Søren Ventegodt ◽  
Isack Kandel
Keyword(s):  
Cerebral Cortex ◽  
Brain Activity ◽  
Sensory Cortex ◽  
Biological Information ◽  
Human Consciousness ◽  
Primary Sensory Cortex ◽  
Sensory Maps ◽  
The World ◽  
The Brain ◽  
The Universe

The structure of human consciousness is thought to be closely connected to the structure of cerebral cortex. One of the most appreciated concepts in this regard is the Szanthagothei model of a modular building of neo-cortex. The modules are believed to organize brain activity pretty much like a computer. We looked at examples in the literature and argue that there is no significant evidence that supports Szanthagothei's model. We discuss the use of the limited genetic information, the corticocortical afferents termination and the columns in primary sensory cortex as arguments for the existence of the cortex-module. Further, we discuss the results of experiments with Luminization Microscopy (LM) colouration of myalinized fibres, in which vertical bundles of afferent/efferent fibres that could support the cortex module are identified. We conclude that sensory maps seem not to be an expression for simple specific connectivity, but rather to be functional defined. We also conclude that evidence for the existence of the postulated module or column does not exist in the discussed material. This opens up for an important discussion of the brain as functionally directed by biological information (information-directed self-organisation), and for consciousness being closely linked to the structure of the universe at large. Consciousness is thus not a local phenomena limited to the brain, but a much more global phenomena connected to the wholeness of the world.

THE ROLE OF OESTROGENS IN SPONTANEOUS OVULATION: LOCATION OF SITE OF ACTION OF POSITIVE FEEDBACK OF OESTROGEN BY INTRACRANIAL IMPLANTATION OF THE ANTI-OESTROGEN I.C.I. 46474

1971 ◽  
Vol 50 (2) ◽  
pp. 321-327 ◽  
Author(s):  
J. G. BAINBRIDGE ◽  
A. P. LABHSETWAR
Keyword(s):  
Cerebral Cortex ◽  
Cocoa Butter ◽  
Median Eminence ◽  
Positive Feedback ◽  
Anterior Pituitary ◽  
Site Of Action ◽  
The Brain

SUMMARY In an attempt to locate the site(s) of action of the positive feedback of oestrogen for ovulation, a potent anti-oestrogen, I.C.I. 46474, was stereotaxically implanted into various parts of the brain or into the anterior pituitary. A dose of 5 μg of the anti-oestrogen when implanted into the cerebral cortex or injected subcutaneously on the morning of the day before pro-oestrus in 4-day cyclic rats was only marginally active in interfering with ovulation. By contrast, when the same amount was implanted into the median eminence region or the anterior pituitary, ovulation failed to occur in 80–100% of the rats (P < 0·05). Implantation of the cocoa butter vehicle alone into these regions interfered with ovulation in less than 35% of animals. Introduction of the anti-oestrogen into the anterior hypothalamic or mammillary region gave equivocal results. The data suggest that both the median eminence and the anterior pituitary contain receptors which can be blocked by the anti-oestrogen with resultant inhibition of ovulation. It is concluded that the positive feedback of oestrogen for ovulation is exerted both at the pituitary and the hypothalamic levels.

scholarly journals Cortical mechanisms of action selection: the affordance competition hypothesis

2007 ◽  
Vol 362 (1485) ◽  
pp. 1585-1599 ◽  
Author(s):  
Paul Cisek
Keyword(s):  
Cerebral Cortex ◽  
Action Plan ◽  
Sensory Information ◽  
Natural World ◽  
Mechanisms Of Action ◽  
Competition Hypothesis ◽  
The World ◽  
Neurophysiological Data ◽  
Single Response ◽  
The Brain

At every moment, the natural world presents animals with two fundamental pragmatic problems: selection between actions that are currently possible and specification of the parameters or metrics of those actions. It is commonly suggested that the brain addresses these by first constructing representations of the world on which to build knowledge and make a decision, and then by computing and executing an action plan. However, neurophysiological data argue against this serial viewpoint. In contrast, it is proposed here that the brain processes sensory information to specify, in parallel, several potential actions that are currently available. These potential actions compete against each other for further processing, while information is collected to bias this competition until a single response is selected. The hypothesis suggests that the dorsal visual system specifies actions which compete against each other within the fronto-parietal cortex, while a variety of biasing influences are provided by prefrontal regions and the basal ganglia. A computational model is described, which illustrates how this competition may take place in the cerebral cortex. Simulations of the model capture qualitative features of neurophysiological data and reproduce various behavioural phenomena.

scholarly journals Inflammation and Cognition in Depression: A Narrative Review

2021 ◽  
Vol 10 (24) ◽  
pp. 5859
Author(s):  
Katarzyna Wachowska ◽  
Piotr Gałecki
Keyword(s):  
Inflammatory Markers ◽  
Health Condition ◽  
Narrative Review ◽  
Brain Areas ◽  
Mediating Factors ◽  
Hormonal Imbalance ◽  
The World ◽  
Depressive Patients ◽  
The Brain

The authors aim to present a narrative review of research on the inflammatory aetiology of depression. Depression is a psychiatric disorder, constituting the most common reason of disability due to a health condition. It has been estimated that at least one in six people suffer from depression at some point of their lives. The aetiology of depression, although researched extensively all around the world, still remains unclear. Authors discuss the possible role of inflammation in depression, the neurodevelopmental theory of depression as well as associations between cognition and depression. Possible associations between memory dysfunction among depressive patients and inflammatory markers are included. The associations between the immune system, depression and cognition are observed. Possible mediating factors between these areas include personality traits, hormonal imbalance and functioning of the brain areas. The question as to what mediating factors are involved is still open to research.

scholarly journals Visual stability

2011 ◽  
Vol 366 (1564) ◽  
pp. 468-475 ◽  
Author(s):  
David Melcher
Keyword(s):  
Cognitive Neuroscience ◽  
State Of The Art ◽  
Brain Regions ◽  
Clinical Neurology ◽  
Visual Stability ◽  
Retinal Motion ◽  
Brain Circuits ◽  
The World ◽  
The Brain

Our vision remains stable even though the movements of our eyes, head and bodies create a motion pattern on the retina. One of the most important, yet basic, feats of the visual system is to correctly determine whether this retinal motion is owing to real movement in the world or rather our own self-movement. This problem has occupied many great thinkers, such as Descartes and Helmholtz, at least since the time of Alhazen. This theme issue brings together leading researchers from animal neurophysiology, clinical neurology, psychophysics and cognitive neuroscience to summarize the state of the art in the study of visual stability. Recently, there has been significant progress in understanding the limits of visual stability in humans and in identifying many of the brain circuits involved in maintaining a stable percept of the world. Clinical studies and new experimental methods, such as transcranial magnetic stimulation, now make it possible to test the causal role of different brain regions in creating visual stability and also allow us to measure the consequences when the mechanisms of visual stability break down.

On the Late Invention of the Stereoscope

Perception ◽  
1987 ◽  
Vol 16 (6) ◽  
pp. 785-818 ◽  
Author(s):  
Nicholas J Wade
Keyword(s):  
Binocular Vision ◽  
Space Perception ◽  
The Body ◽  
Visual Direction ◽  
The Third ◽  
Visual Distance ◽  
Third Dimension ◽  
Late Invention ◽  
The Brain ◽  
Binocular Depth

It was not until 1838, when Wheatstone published his account of the stereoscope, that stereoscopic depth perception entered into the body of binocular phenomena. It is argued that the stereoscope was not invented earlier because the phenomenon of stereopsis based on disparity had not been adequately described. This was the case despite the fact that there had been earlier descriptions of tasks that could be performed better with two eyes than with one; the perceptual deficits attendant upon the loss of one eye had been remarked upon; analyses of the projections to each eye were commonplace, and binocular disparities were accurately illustrated; moreover, binocular microscopes and telescopes had been made over a century earlier. Theories of binocular vision were generally confined to accounting for singleness of vision with two eyes, and the concepts employed to account for this were visible direction, corresponding retinal points, and union in the brain. The application of these concepts inhibited any consideration of disparities, other than for yielding diplopia. When perception of the third dimension was addressed by Berkeley at the beginning of the eighteenth century, it was in the context of monocular vision and binocular convergence. Thereafter visual direction became the province for binocular vision and it was analysed in terms of geometrical optics, whereas visual distance was examined in the context of learned associations between vision and touch. This artificial division was challenged initially with respect to visual direction and later with respect to stereopsis. An additional factor delaying the invention of the stereoscope was that experiments on binocular vision generally involved abnormal convergence on extended objects. Wheatstone's accidental observation of stereopsis was under artificial conditions in which disparity alone defined the binocular depth perceived. Once invented the stereoscope was enthusiastically embraced by students of vision. It is suggested that the ease with which retinal disparity could be manipulated in stereopairs has led to an exaggeration of its importance in space perception.

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