In this post, I attempt to present two major metaphysical accounts of space by Kant and Leibniz, then present some recent findings from cognitive neuroscience about the neural basis of spatial cognition in an attempt to understand more about the nature of space and the possible connection of philosophical theories to empirical observations.

Immanuel Kant’s account of space in his Prolegomena serves as a cornerstone for his thought and comes about in a discussion of the transcendental principles of mathematics that precedes remarks on the possibility of natural science and metaphysics. Kant begins his inquiry concerning the possibility of ‘pure’ mathematics with an appeal to the nature of mathematical knowledge, asserting that it rests upon no empirical basis, and thus is a purely synthetic product of pure reason (§6). He also argues that mathematical knowledge (pure mathematics) has the unique feature of first exhibiting its concepts in a priori intuition which in turn makes judgments in mathematics ‘intuitive’ (§7.281). For Kant, intuition is prior to our sensibility and the activity of reason since the former does not grasp ‘things in themselves,’ but rather only the things that can be perceived by the senses. Thus, what we can perceive is based on the form of our a priori intuition (§9). As such, we are only able to intuit and perceive things in the world within the framework naturally provided by the capabilities and character (literally the under–standing) of our understanding. Kant then takes our intuitions of space (and time) as concepts integral to pure mathematics and as necessary components of our intuition (§10.91).

Kant develops that geometry is based on this pure intuition of space (and arithmetic on that of time) and advances that even after removing all sensations and empirical intuitions, the intuitions of space and time remain, proving them as the a priori intuitions that precede any form of empirical experience or sensation (ibid.103). Thus, our experience of space and the means by which we do geometry is a component of our intuition for Kant and does not require the existence of direct objects of experience. Rather, our awareness of things as they appear in space is woven into our intuition and is a basic characteristic of our experience. Kant goes on to describe space as the “form of outer intuition of our sensibility” in that it is the thing in which we perceive things, i.e. that it is a transcendental condition for sensation (§13.317). By this, we arrive at our understanding of the arrangements of objects in the world not by an empirical encounter, but by the form of our intuition. Therefore, Kant’s account makes geometry an intuitive practice that utilizes a basic component of our pure a priori intuition as opposed to our rational activity. In support, Kant offers that we determine a geometrical concept, e.g. congruency, not through concepts formed by reason, but through relations that are apparent as a result of our pure intuition (ibid.325).

Kant’s theory stands in stark contrast to that of Leibniz, whose account of space is intelligible through arguments in his Discourse on Metaphysics and Monadology. In the former Leibniz foreshadows the concept of the monad in arguing, “each singular substance expresses the universe in its own way,” which develops that the constituent, most fundamental components of reality itself are unique and infinite in number and contain all things present, past and possible (DM.9). In the latter work, Leibniz reiterates that each monad must be different from each other because no two monads can be identical, further establishing the notion of an infinite number of infinite substances that make up the universe (M8-9). Accordingly, objects in the world are made up of monads, which are self contained and distinct from one another. Based on Leibniz’s theory, we arrive at a higher order reality in which everything is separate, distinct and self-contained and therefore, space comes about as a consequence of the existence of objects. That is, when we perceive Leibnizian space, we perceive a thing produced as a result of the existence of two other separate objects.

Leibniz’s account of space also has implications for geometry. By his theory, our perceptions of congruent things for example, become a comparison of two objects made in perception and understood actively by reason. Evidence for this can be found in Leibniz’s arguments concerning physics and causality. Leibniz believes that God constructed the world (with monads) and everything in it in the best possible way (M1,3). As such, the universe carries a predetermined and pre-established order of cause and effect (M6,7) and Leibniz argues that we come to understand nature by finding causes from effects by the use of reason (DM19). Therefore, geometry becomes a rational activity when viewed from a Leibnizian perspective because it is an investigation of that which exists. For Leibniz, we must necessarily invoke our understanding of the nature of objects in the world to do geometry, and this conflicts with the intuitive nature that Kant ascribes to geometry. For Kant, our knowledge (or ‘cognition’) of space is a result of the form of our intuition that comes before sensibility, which makes our understanding of geometry intuitive. For Leibniz, space exists only because discrete objects exist in the world and our understanding of geometry comes from rational manipulations of those objects. Nevertheless, both Kant and Leibniz provide accounts for space that necessarily involve an a priori component rather than perception alone.

Cognitive neuroscientists are now suggesting that spatial cognition is a complex interaction of multiple brain circuits in parallel that make use of both allocentric and egocentric processing of the external world. A pivotally important concept in understanding spatial cognition has been the investigation of representation in the brain. “Representation” is a term that has been used in philosophy for centuries, and science is now using the term to refer to the neural picture of the external world as observed by our brain monitoring and imaging technology. The investigation of representation in the brain essentially involves solving the puzzle of how the world itself is represented physically in the brain. With respect to spatial cognition, the discovery of grid cells in 2005 suggests that a euclidean space is encoded in the brain itself by neurons, and that activation and deactivation of grid cells plays a major role in representing the spatiality of the external world to the perceiver. The discovery of grid cells also suggested a mechanism for the perception of one’s own location that is continually updated by input from the external world, suggesting that, similar to visual perception, the representation of space in the brain itself is an active phenomenon that varies just as much as the visual field.

Most, if not all, of the work on spatial perception and grid cells is performed on rats and conclusions made are inductively applied to humans, which makes us doubt how accurately these mechanisms can apply to the human brain. I say this because while many other studies of physiological phenomena in rats or mice (e.g. those on the cardiovascular and immune systems) may be stronger due to the increased homology to humans present in those systems. In other words, I think that the human and the mouse/rat brain differ quite significantly, perhaps more so than other organs and that this reduces the strength of our inductive conclusions. However, interesting studies are now being performed on humans which place a subject in a virtual maze through a computer program and measure brain activity through noninvasive methods such as functional MRI (fMRI). Many recent studies are pointing to the hippocampus as a major player in way finding and general navigation through virtual mazes, which suggests that our spatial perception is an evolutionarily refined phenomenon, but also one that is fundamental to our basic neural make up. Interestingly, the neural phenomena change when scientists investigate spatial cognition relative to landmarks (i.e. objects) as compared to studies in simple maze navigation. In these object-centric experiments, subjects navigated mazes and were cued with objects present in the virtual environment that they had to collect and place in a distinct virtual location, either at a specific landmark or in a general bounded area. Brain scans in these studies showed both hippocampal and striatal activation during the performed tasks, with hippocampal activity associated with the boundary task and striatal activity associated with the landmark task. Further, separate studies in rats performing similar spatial boundary tasks reveal that the activation of hippocampal “place cells” fire in boundary-space tasks, which scientists think are creating a matched representation of distances and angles relative to the boundaries in the visual field. Results from striatal activation are still unclear and are being more closely investigated. It has also been suggested that the hippocampal and striatal circuits act in parallel rather than in series or in combination. This makes sense given that spatial cognition may involve both boundary and landmark elements, as when we have to hammer a nail into a specific location or plug something into a power outlet.

Relating the philosophy and neuroscience presented in this post, it seems that both Kantian and Leibnizian conceptions of space are compatible with neuroscientific findings about spatial cognition. Kant’s theory applies to the current understanding of hippocampal, boundary influenced tasks in that both suggest a holistic conception of space – that is, space can be understood as object independent. On the other hand, Leibnizian conceptions of space and the landmark results suggest a more object-dependent framework for spatial cognition. As spatial cognition and perception are our most direct means to accessing and interacting with the external world, both scientists and philosophers of the future ought to work together on this enormously complex problem in an effort to postulate how spatial phenomena as presented to us by the mind relate to neural phenomena in the brain. Perhaps then we will move closer to filling the explanatory gap between the mind and brain.

Prolegomena – Kant
Discourse on Metaphysics – Leibniz
The Monadology – Leibniz
Spatial Cognition and the Brain – Neil Burgess

Philosophy of Mind came into its most compelling forms during the age of modern philosophy beginning with René Descartes. Perhaps infamously, Descartes claimed that mind and body are two distinct substances – philosophical jargon for what exists without the aid of any other thing. For Descartes, the world was clearly and distinctly physical in one sense and entirely mental in another. This seems perplexing, and Descartes did concede that the mind and body were closely intertwined and appeared to act with respect to one another, but his arguments clearly press that they are not causally connected in any way. These notions of dualism seem nearly preposterous with the advent of modern science, but were nonetheless important in developing our thought about the mind in the modern era.

Dualism gave rise to other interesting, yet now strongly refuted movements. One of these was idealism, or the doctrine argued famously by George Berkeley that states that all that exists are either ‘ideas’ or minds that perceive them. In this sense, an idea is defined as that which is perceived, inclusive of information imprinted on the senses, passions and operations of the mind, and conceptions formed by imagination and memory. Importantly, Berkeley argues that these ideas exist ‘in the mind’ exclusively: that is, they are purely mental and all things are simply combinations and aggregations of ideas. These immaterial ‘ideas’ then, are the only objects of human knowledge under idealism, and this theory denies the existence of physical objects entirely! The notion seems preposterous, but there is a very interesting argument found within idealism that can throw our conception of perception for quite the proverbial loop.

One of the main arguments against idealism is the apparent true existence of material objects in the external world. Modern science has allowed us to know with a degree of certainty that we exist in a world that contains physical entities separate from our mental space. Bertrand Russsel, a physicalist, famously made such arguments for the existence of the material world. He coined the term ‘sense data’ to refer to that which we perceive from objects in the environment, e.g. the light rays reflecting off of them. In his thinking, this sense data is caused by an actual material object in the external world, thus endorsing the existence of physical objects. This certainly seems more plausible than idealism given our current level of understanding about the physical world. However, the idealist refute of physicalism draws on an idea called perceptual relativity that is interesting in itself and worth knowing about.

A simple philosophical approach to perception.

Perceptual relativity works similarly to the theory of relativity from physics, but applies it to perceptual content, and it is with this crafty syllogism that an idealist can argue that nothing really exists outside our own minds and ideas. If the idealist accepts that the objects perceived are ideas that exist only within the mind of the perceiver and those things are made up of more ideas which also only exist in the mind of the perceiver, it follows that each perceiver apprehends a different object entirely, rather than a different affection of the same object as a consequence of having different points of view. In other words, each person looking at a common object perceives an entirely unique object, just as if they were looking at two completely different things, e.g. a house and a boat. This seems absurd, but it is nonetheless effective for arguing the physical world out of existence. Taking ideas as exclusively mental phenomena, it remains logically valid to argue that each person perceives a different idea when looking at the same object in that different angles or in different levels of light and shadow make the object of each person’s perception unique to them alone.

Your may see squares A and B as different shades of grey. Look again - they are identical.

While the argument from perceptual relativity is interesting, it remains completely absurd in our modern context. Given that we can forcefully argue for the existence of the material world down to the level of molecules, atoms and subatomic particles that (perhaps) move faster than the speed of light, the idealist well seems to have run dry. It seems evident, if not universally true, that there is an external world filled with a variety of physical objects that exist in a space outside our minds. We may have thoughts of said objects and file them into our minds, but it by no means follows from this that an object solely exists in our minds and is not like the ideas of others about the same object. However, the flip side of this comfortable position would make an assertion about material objects themselves. What are they really made of? On a deep level, they are simply electricity – energetically favorable collisions of packets of energy that are perceived by our sense organs and constructed into a nice, organized stream of consciousness by our brains. To get even loftier, we’ve developed quite a system to differentiate all the different types of electricity out there by giving them names like tree, book or cheeseburger. These are really just ideas about the various clouds of electricity we interact with every day, so how far from idealism have we really come? Are our ideas about voltage simply existing within our own minds as a function of the information our brain is wiling to let us perceive?

What do you see?

References:

Treatise Concerning Human Knowledge – George Berkeley

The Problems Of Philosophy – Bertrand Russell

Sebastian Seung is a professor of computational neuroscience and physics at MIT. His research in the neuroscience field involves “connectomes,” or the map of connections between and among neurons. The endeavor of investigating and mapping connectomes began in the 1980s and jumped off with the elucidation of the complete connectome of the worm C. elegans in 1986. While C. elegans has about 300 neurons, humans have about 10 billion neurons and ten times that number of connections. These connections can grow and change with and from neural activity and experience, combining to permutations exponentially greater that those of DNA and its four bases. Seung proposes that we “are our connectomes” rather than our genomes, implying that our thoughts, experiences, emotions, and consciousness itself may have a purely neural basis. To refrain from any more spoilers, he artfully expands and explains his hypothesis in the above TED talk that it is surely worth viewing. For a greater philosophical inquiry inspired by his ideas, is our matter all that matters?

Can you hear me now? For years, it has been popular doctrine that cell phone use is bad for our brains, but we glue our phones to our ears anyway. Cell phones emit radio frequency-modulated electromagnetic fields (RF-EMFs) that are questioned for their potential danger when the brain is exposed to them. The oscillatory frequencies of RF-EMFs correspond to those measured in neural tissue, and thus could interfere with neural activity. The amount of electromagnetic radiation given off by our communication devices is small, but is radiation all the same. Radiation exposure is dangerous for any kind of cell in our body, and can penetrate cells and damage DNA either by crashing into the molecule directly or causing damage indirectly by forming free radicals from water that can have cancer-causing effects.

Now, a study that empirically investigates the effects of cell phones on the brain with acute cell phone exposure with PET imaging from the National Institute on Drug Abuse has been published in the Journal of the American Medical Association (JAMA). The study investigates if acute cell phone exposure affected activity in the brain by measuring glucose metabolism via PET in subjects with two cell phones affixed to their ears. Readings were obtained with one cell phone antenna activated for 50 minutes (the “on” condition) and with both off (the “off” condition) for control and comparison purposes. Subjects were exposed to either condition and imaging of their brains was analyzed, revealing that whole-brain effects were not significant, but there was significant activation in areas of the brain in the immediate vicinity of the cell phone, justifying our concerns with cell phone radiation. Brain mapping (below) shows the strength of the electric field provided by the affixed cell phone mapped against the brain itself. Magnitude was markedly increased near the antenna, increasing significantly closer to the phone and reaching maximum strength near the lower temporal lobe.

PET scans (below) of the control condition (cell phone off) versus the experimental condition (cell phone on) at the level of the orbitofrontal cortex. Clear increase in glucose metabolism was demonstrated in the right orbitofrontal cortex and the lower right superior frontal gyrus. These brain regions are associated with decision-making and sensory-aided self awareness, respectively. Additional statistical analysis showed that glucose metabolism is positively correlated with the strength of the electric field exposed to the brain. The researchers interpret the spikes in activity as increases in neuronal activation, providing scientific evidence that our cell phones are affecting our brains.

Although no justified claims can be made between this study’s observed brain activity increase and brain cancer of other pathology, the results show that cell phones do have an observable effect on our brains. The authors suggest that further study is needed to elucidate the mechanism by which electric fields stimulate increased brain activity, and that the link between electric fields and neuronal excitation must be corroborated. The researchers are not sure of the implications of this observed increase in neural activation, positive or negative, but research must be continued in this area so we can learn how our technology is affecting our brains. The areas affected included those for decision making and sensory awareness, but it is unclear how activation of such areas can effect behavior or thought. Do cell phones make us impulsive? Do they make us hyper-sensitized or unaware of our other surroundings? What can you do? If this study has alarmed you, one of those headsets would work wonders – just be prepared to look like you’re talking to yourself on the street!

Effects of Cell Phone Radiofrequency Signal Exposure on Brain Glucose Metabolism – JAMA

Parkinson’s disease is one of the most infamous neurological disorders known to medicine and has afflicted many, including Muhammed Ali and Michael J. Fox.  Described by it’s characteristic tremors and shaking, the disease induces loss of control of motor function as a result of neuronal death in dopamine-releasing (dopaminergic) neurons in a midbrain structure called the substantia nigra. In the pathology of Parkinson’s Disease, this localized population of dopaminergic neurons start to die, while other neurons in the substantia nigra and other local dopaminergic neurons remain healthy and functional. This has puzzled researchers extensively, but a recent letter to Nature provides some breakthroughs in understanding what is happening in these degenerative neurons.

Muhammed Ali and Michael J. Fox are two celebrities battling Parkinson's Disease.

Recent research into Parkinson’s suggests that the problems are localized to the mitochondria of the suspect neurons, leading to the conclusion that the disease is related to problems with metabolism. The mitochondria are the machines of cell metabolism and the stage for the Kreb’s Cycle and the Electron Transport Chain (ETC), which are the two major energy producing processes of the cell. The metabolism occurring in the mitochondria produces large amounts of adenosine triphosphate (ATP) which is used as energy currency in all cells of the body, and also lead to the production of water to be used elsewhere by the cell. Oxidative stress in the water producing portion of the metabolic pathway can lead to the production of oxygen free radicals, which are highly reactive as a result of a single free electron (free radicals have implications in other degenerative disorders and cancer). Scientists now suspect that these free radicals are contributing to the neurodegenerative consequences of Parkinson’s Disease.

Neuroimaging study showing the decreased neuronal activity in Parkinson's Disease.

In the Nature study, scientists tagged the mitochondria of the Parkinson’s suspect neurons with fluorescent protein that would allow them to observe oxidation states of the cells in rats. They found that Parkinson’s cells were in fact under a high level of oxidative stress and showed stress patterns at regular intervals, concluding that the cells function rhythmically when releasing dopamine. This rhythmic function is associated with ATP driven increases of calcium levels in the neurons, and the study suggests that this rhythmic calcium fluctuation is the instigator of the oxidative stress associated with Parkinson’s disease. In further experimentation, the researchers blocked these calcium influxes with drugs, which led to a decrease in Parkinson’s-like oxidative stress  in mouse models of early-onset Parkinson’s disease. These drugs are known to be tolerated by humans well, and provide a legitimate option for medicinal therapy in the disease.

Oxidant stress evoked by pacemaking in dopaminergic neurons is attenuated by DJ-1 – Nature 2010

Crossing the gap at the wrong time can be devastating.

In the 1700s, David Hume proposed what has now become known widely as the Is-Ought Problem. He calls for caution in making statements about morality or what “ought” to be based on extrapolations of what “is” and that what ought to be does not necessarily follow from what is. The problem aptly applies to neuroscientists like Saxe whose research make strong suggestions about the neural basis of existence and attempts to bridge the is-ought gap. All of this research is establishing a large library of what “is” concerning the brain, but it also suggests that metaphysical concepts such as morality and meta-ethics can be reduced to neurological connections and connectivity. Hume stresses that while what is and what ought to be are important revelations in and of themselves, what ought to be need not follow from what is. Neuroscience must understand this separation as its advances begin to encroach on many of philosophy’s already well-established concepts.

Brain activity is only one component of our consciousness.

What I’m saying here is that modern neuroscience must use caution in making conclusions about human nature. Empirical evidence can certainly be used to help understand more abstract ideas, but the evidence and the ideas must remain seperate with respect to causality. Making discoveries about brain function and the empirical science behind things like emotion or judgment is a valiant and respectable scientific investigation. However, this pursuit must be kept separate and distinct from the pursuit of understanding how we ought to be or act. Our moral thought is something more abstract and multidimensional than connections between neurons and sequential acton potentials. While investigation of the science of the mind is important, it should not seek to explain our existence nor try to answer philosophy’s greatest problems with calculations and empirical data.

For reference:

The Is-Ought Problem – David Hume via Wikipedia

Theory of Mind TED Talk – Rebecca Saxe (MIT)

David Hume, Meta-Ethics – Wikipedia

The Big Bang Theory is a commonly accepted scientific theory of creation

Now, neuroscience has something to say about this “God experience.” Michael Persinger, a cognitive scientist at Laurentian University in Canada believes that God lives within our own brains, implying that these mystical experiences may be contrived. He has developed a neuroethological apparatus deemed the “God Helmet” that seems to induce the feeling of another being’s presence to it’s wearer. The device is modeled off of a snowboarding helmet and contains metal coils that cover the whole brain with a magnetic field when fully powered up. The subject puts on the helmet and then sits in a dark, comfortable room with eye coverings as the coils are activated. In the experiments, magnetic activity above the right temporal lobe elicits the most intense feeling of presence of other beings to the wearer. Persinger reports that 80% of the helmet’s wearers experience presence of another being, or the so-called “God sense.” The idea here is that the brain itself is creating the feeling of divine presence without the presence of the divine. Given Persinger’s results, neuroscience says that we may have created our creator, and that the divine is nothing but a function of our own brain activity. Maybe those that claim to have danced with the divine simply have above normal temporal lobe activity. This research also sheds light on the more familiar feeling that someone is “watching you,” which is essentially the same feeling of presence.

A subject in a God Helmet experiment

It is safe to say that we may never know if our creator resides inside our own minds, in another inaccessible dimension or walks among us. Until then, we can only investigate our own existence as a function of what we can observe or from what we can infer about information we have already obtained. For a more in depth exploration of the creator question, check out Discovery Channel’s “Through The Wormole” narrated by Morgan Freeman (just follow the consecutive parts!).

An article about Persinger’s God Helmet

The “Through the Wormhole” segment on Persinger’s work

Wikipedia articles on the God Helmet and Persinger

Vision is one of the most impressive functions of the human brain. It interprets nothing but electromagnetic waves and paints a glorious picture of our daily existence from the scattered chaotic sea of intertwining light waves that we call home. Many see their vision deteriorate and the world blur as time goes on and these problems can be corrected by optometry, but blindness comes on like a relentless infidel for more than two million people worldwide in the form of retinitis pigmentosa (RP). RP is a heritible genetic disorder that leads to degeneration and loss of function in the retina’s photoreceptor cells, and can lead to full blindness in a matter of years. There is no cure or treatment for RP, but new research may change that very soon.

TOP: Macroscopic human eye (left) and rod and cone cell arrangement on the retina (right). BOTTOM: Normal human retina (left) and human retina with retinitis pigmentosa (right)/(Source: Medical-Look.com)

Vision starts in the photoreceptor when light activates rhodopsin, a G-protein coupled receptor pigment consisting of light sensitive opsin and retinal. Light triggers a conformational change in retinal that kick starts a G-coupled visual cascade and the flow of visual information to the brain. In retinitis pigmentosa, rhodopsins in the photoreceptors become insensitive to light starting in the rod cells, and blindness sets in gradually. Rod cells are used in low light and deteriorate first, leading to night blindness, and dysfunction in cone cells used for color vision and acuity sets in until full blindness plagues the individual. Fortunately, a team of French scientists has investigated this degradation and has found a way to combat it by reactivating the photoreceptor cells through genetics. Their study was featured in the July 23rd issue of Science.

Artificially colored micrograph image of retinal rods (yellow-green) and cones (blue). (Credit: Science Photo Library @ sciencephoto.com)

The scientists isolated an achaebacterial rhodopsin analog called halorhodopsin that functions in the yellow and green wavelength range. They then introduced a halorhodopsin encoding gene into retinitis pigmentosa model mice via a viral vector and also created a control group. In their experiments, it was found that both slow and fast degrading retinal cells in the experimental mice regained their light sensitivity in response to integration of halorhodopsin into their insensitive photoreceptor cells. Electrical responses were recorded from ganglion cells (the third tier cell in the visual cascade) and healthy photoreceptor spikes were observed in response to light stimulation. Most importantly, lateral inhibition (the mechanism by which the brain discriminates edges of objects) was fully preserved, while mono-directional movement was retained. Halorhodopsin mice also performed significantly better than the control RP mice in a battery of visually guided tasks, demonstrating that their photoreceptors had been successfully resensitized by halorhodopsin integration. The scientists also tested the resensitizing ability of halorhodopsin on cultured human retinal cells. They were successful in integrating halorhodopsin into human cells via viral vectors, but could not conduct any clinical trials. However, photoreceptors expressing halorhodopsin demonstrated photocurrents and photovoltages that would be adequate to restore human vision.

Theoretical device that allows a halorhodopsin treated patient to see by projecting patterned light onto the eyes derived from camera input. (Credit: Y. Greenman/Science)

This opens the door to treatment of retinitis pigmentosa in the genes – the same place where it starts. Although halorhodopsin therapy will not fully restore all wavelengths in human vision, it can still serve as a tool to bring restore vision in the blind through optical devices. For example, an RP patient could be treated with halorhodopsin gene thearpy, then outfitted with a device that images the visual field and translates it into halorhodopsin recognizable wavelengths. This light mosaic is then projected onto the patient’s eyes and the can “see” what is in front of them. The supplied image of the device is from a perspective article in the beginning of the current issue of Science.

View the full text Science article here (HTML) or here (PDF) and the perspective piece about the article here. Be sure to discuss in the comments!

Sources:

Seeing the Light of Day - Science (Perspective)

Genetic Reactivation of Cone Photoreceptors Restores Responses in Retinitis Pigmentosa - Science (Research Article)

Researchers at the Norwegian University of Science and Technology are conducting research that creates a causal link between motor and learning disabilities and dysfunction in visual perception. For example, people who cannot quickly learn a simple motor task such as catching a ball may have difficulty because the cells in their eyes are not perceiving the stimulus properly. The same rings true in individuals with dyslexia – their eyes may not be correctly processing the visual stimuli of words on the page.

Learning disability has long puzzled victims, observers and scientists.

The ocular cells in contest here are deemed “magno cells” and detect rapid movements in our visual field, creating the movie-like perception we experience on a daily basis. Without these, life would look like a disconnected string of frames – much like a comic book. In a test conducted by the researchers, it was found that individuals with difficulty in mathematics also showed difficulty in tracking the randomized movement of a dot on a screen with their eyes, elucidating a link between eye function efficiency, detection of rapid changes in the environment and learning ability.

In a greater context, this finding may have implications in special education and may change the mindset of those working with individuals with additional learning needs. With this new information, learning disability can be combated from the angle of visual field perception. Techniques aiming to strengthen visual perception and eye efficiency (such as eye movement and tracking exercises) could act as a therapy for learning or motor disability previously thought to be localized in the brain itself.

Source: Science Daily via The Norwegian University of Science and Technology

With finals around the corner, the stress factor on campus is bound to rise in the next few weeks. Individual students have their own way of coping with stress, such as TV, video games, music, power naps at Mugar Library (the cubbies are quite comfortable) or a marathon visit to FitRec. Regardless of the method, all aim to reduce the anxiety of coming exams.

Stress also has a neurophysiological effect that decreases rates of neuroplasticity (the ability for the brain to “rewire” itself) in the hippocampus – an area believed to be a center of learning and memory. Additionally, new research suggests that there is a genetic basis for stress effects on the brain connected to a protein called brain derived neurotrophic factor (BDNF). In a joint study conducted by Rockefeller University and Weill Cornell Medical College researchers, it was found that mice with inadequate BDNF expression had brains that looked similar to those of mice exposed to chronic stress over a long period of time. These mice were not exposed to chronic stress, yet they still showed decreased rates of neuroplasticity in the hippocampus – a characteristic of stressed brains.

It seems that stress is a product of our environment as well as our genes. At this point, research on BDNF is just beginning. However, this research might open doors to the treatment of chronic stress disorders on the genetic and physiological level without the use of controversial psychotropic drugs.

Read the full article over at Science Daily for the whole scoop.

Gene That Changes the Brain’s Response to Stress Identified

via Science Daily