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How Does The Brain Process Visual Information

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How Does The Brain Process Information

Visual Processing and the Visual Cortex

The human brain is a complicated, creative information-processing system. As technology advanced from primitive to modern, the metaphors used to describe the brain also advanced. Initially, it was compared to a wax tablet, then to a sheet of papyrus, then to a book, and most recently, to a computer. As you learn about the brain, keep in mind that the usefulness of these metaphors is limited and can lead to erroneous conclusions.

Information processing starts with input from the sensory organs, which transform physical stimuli such as touch, heat, sound waves, or photons of light into electrochemical signals. The sensory information is repeatedly transformed by the algorithms of the brain in both bottom-up and top-down processing. For example, when looking at a picture of a black box on a white background, bottom-up processing puts together very simple information such as color, orientation, and where the borders of the object are – where the color changes significantly over a short space – to decide that you are seeing a box. Top-down processing uses the decisions made at some steps of the bottom-up process to speed up your recognition of the box. Top-down processing in this example might help you identify the object as a black box rather than a box-shaped hole in the white background.

The Nose And Nasal Cavity

Olfactory sensitivity is directly proportional to spatial area in the nosespecifically the olfactory epithelium, which is where odorant reception occurs. The area in the nasal cavity near the septum is reserved for the olfactory mucous membrane, where olfactory receptor cells are located. This area is a dime-sized region called the olfactory mucosa. In humans, there are about 10 million olfactory cells, each of which has 350 different receptor types composing the mucous membrane. Each of the 350 receptor types is characteristic of only one odorant type. Each functions using cilia, small hair-like projections that contain olfactory receptor proteins. These proteins carry out the transduction of odorants into electrical signals for neural processing.

The Olfactory System: A cross-section of the olfactory system that labels all of the structures necessary to process odor information.

Olfactory transduction is a series of events in which odor molecules are detected by olfactory receptors. These chemical signals are transformed into electrical signals and sent to the brain, where they are perceived as smells.

Olfactory Nerve: The olfactory nerve connects the olfactory system to the central nervous system to allow processing of odor information.

Processing Of Face And Place Stimuli

Past models of visual processing have distinguished certain areas of the brain by the specific stimuli that they are most responsive to for example, the parahippocampal place area has been shown to have heightened activation when presented with buildings and place scenes , whereas the fusiform face area responds mostly strongly to faces and face-like stimuli .

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Neuroscience Is Deeply Humbling

I dont want people to read this and think we cant believe our eyes, or we cant incorporate evidence into our thinking. We can seek out verified sources of information. We can turn to expertise and also earnestly question it.

Instead, the illusions and the science behind them raise a question: How do we go about our lives knowing our experiences might be a bit wrong?

Theres no one answer. And its a problem were unlikely to solve individually. Id suggest that it should nudge us to be more intellectually humble and to cultivate a habit of seeking out perspectives that are not our own. We should be curious about our imperfections, as that curiosity may lead us closer to the truth. We can build cultures and institutions that celebrate humility and reduce the social cost for saying, I was wrong.

This isnt easy. Our psychology makes it hard. We have this naive realism that the way we see the world is the way that it really is, Balcetis told me last year. Naive realism is the feeling that our perception of the world reflects the truth.

But illusions remind us it does not. This is why illusions arent just science theyre provocative art. They force us to reinterpret our senses, and our sense of being in the world. They tell us about the true nature of how our brains work: The same neurological machinery that leads us to discover the truth can lead us to perceive illusions, and our brains dont always tell us the difference.

How The Eyes Communicate With The Brain

Deciphering how the brain encodes color and shape

When we decide to look at something, a brainstem structure called the pons is called into action. It controls eye movement, constantly telling our eye muscles to move toward the correct stimulus of light .

When light enters the eye through the pupil, it strikes in the retina called rods and cones. Rod cells are responsible forperipheral vision and night vision, while cone cells react to brighter light, color and fine details.

When light hits its corresponding rod or cone, the cell activates, firing a nerve impulse through the optic nerve the middle man between the eye and the brain.

This impulse travels across countless nerve endings and eventually ends up with our pal the occipital lobe, where its processed and perceived as a visible image. This is eyesight.

Since an image isnt much help without meaning, the occipital lobe sends this visual information to the hippocampus in the temporal lobe. Here its stored as a memory.

All of this happens within the tiniest fraction of a second, allowing us to perceive the world in essentially real time.

The human brain is an incredibly complex web of neurons and synapses. And the more we understand about its mind-boggling ability to process and make sense of random collections of light, the more we can appreciate the equally complex world around us.

STILL HAVE QUESTIONS ABOUT YOUR BRAIN AND VISION? Talk to an eye doctor near you to schedule an appointment.

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Better Retention And Comprehension With Visual Content

The use of visual content has a profound effect on our brains ability to learn and process new information. A combination of words and pictures has proven time and again to be a more effective teaching tool than words alone.

For example, as Ruth Colvin Clark and Richard E. Mayer write in their book, e-Learning and the Science of Instruction, accompanying text-based instructions with a graphic improved students performance on a test by a median amount of 89%. Whereas students had gotten less than 40% of answers correct after reading a text comprised of words alone, the number of correct answers improved to around 65% when words were combined with graphics.

Meanwhile, color can play a strong role in memory too. Scientists have observed a significant improvement in memory recognition when study participants are presented with color images vs. black-and-white images. While these studies didnt compare images to text, it can perhaps be concluded that color graphics might offer a similar improvement in memory over text, which is generally presented in black and white.

The so-called multimedia principle, which posits that people learn more deeply from words and graphics than from words alone, has become among the most well-established educational principles, and has been applied widely in educational spheres.

Visual Processing Isnt All One Way

This bottom-to-top processing of our visual world may seem the logical path, but it isnt the whole story. Such a ‘bottom-up‘ approach would be far too slow and laborious, but more importantly, it would render our visual world full of ambiguity and we would struggle to survive. Instead, our perception relies to a very large extent on our previous experience and other ‘top-down‘ mechanisms such as attention. QBI Professors Jason Mattingley and Stephen Williams are both studying how attention can alter visual processing, using cognitive and cellular approaches, respectively.

As an example of top-down processing, consider the image below:

Wuhazet – Henryk ychowski

Square A looks lighter, but is actually darker than square B. Clearly, our visual system is doing a terrible job at seeing reality. But that isnt its purpose. Instead, our brains are trying to make sense of what they are seeing, rather than seeking the truth.

In the case of the above image, we automatically see based on past experience light and dark squares arranged in a checkerboard fashion, with a centrally lit portion and a shadow cast around the edges. With all of this information, we interpret A as a light square in shadow, and B as a brightly lit dark square. It isnt reality, but it is the most likely explanation given all of our previous experience and the data at hand. This is how our visual system works, ultimately to help us understand the world and so promote our survival.

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Humans Process Visual Data Better

Organizations of all stripes, shapes and sizes are drowning in a tidal wave of data.

When you look at just how much big data has expanded, it can be alarming. For example, Google receives more than 2 million search queries every minute. On a larger scale, humans are currently generating an estimated 2.5 quintillion bytes of data every single day.

Heres one way to look at this stat: 90 percent of the worlds data has been created in the last two years alone. The rise of a multitude of sources from social media to the web to the expanded use of sensors is making it difficult for organizations to make sense of the data. When this occurs, it is nearly impossible to translate the information into something actionable that provides a tangible return-on-investment .

Thankfully, the rise of visual data displays or data visualization is helping to meet this need.

Visualization works from a human perspective because we respond to and process visual data better than any other type of data. In fact, the human brain processes images 60,000 times faster than text, and 90 percent of information transmitted to the brain is visual. Since we are visual by nature, we can use this skill to enhance data processing and organizational effectiveness.

Human beings are visual creatures. As such, the time is right for organizations to implement new solutions for leveraging data visualization and unlock their true potential to meet mission and business goals.

What Visual Perception Tells Us About Mind And Brain

How does the brain process visual information faster in those with VSS?
  • *Division of Biology/Computation and Neural Systems, California Institute of Technology, Pasadena, CA 91105 Department of Neuroscience, Brown University, Providence, RI 02192 and §Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
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      The Dorsal And Ventral Streams

      After the visual stimulus leaves the eyes, it is first processed through distinct points in the brain along the path to the occipital lobes. Then, that information exits the occipital lobes in white matter tract pathways called streams to other parts of the brain. The ventral stream is involved with object and visual identification and recognition. The dorsal stream is involved with processing the objects spatial location. In other words, the brain is figuring out what to do with the visual information it has received how to use it to recognize persons seen before map routes recognize symbols and letters and many other interpretations. These streams run through the temporal and parietal lobes, which is why sometimes surgery to these parts of the brain can affect visual processing as well.

      The dorsal stream guides your actions and helps you recognize where objects are in space. Also known as the parietal stream , the where stream, or the how stream, this pathway stretches from the primary visual cortex in the occipital lobe forward into the parietal lobe. It is interconnected with the parallel ventral stream which runs downward from V1 into the temporal lobe.

      The dorsal stream is primarily involved with the perception and interpretation of spatial relationships, accurate body image, and the learning of tasks involving coordination of the body in space. Damage or disruption to this stream can cause visual processing issues, including:

      Cortical Processing Of Visual Input

      From the thalamus, visual input travels to the visual cortex, located at the rear of our brains. The visual cortex is one of the most-studied parts of the mammalian brain, and it is here that the elementary building blocks of our vision detection of contrast, colour and movement are combined to produce our rich and complete visual perception.

      Most researchers believe that visual processing in the cortex occurs through two distinct ‘streams’ of information. One stream, sometimes called the What Pathway , is involved in recognising and identifying objects. The other stream, sometimes called the Where Pathway , concerns object movement and location, and so is important for visually guided behaviour.


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      Pathways Of Information In The Visual System

      Within the visual system, researchers seek to explain our seamless perception of a three-dimensional surround that contains color, movement, and shape, all assembled from the action of light on our two eyes. What takes place in the rest of the brain, beyond the 125 million rods and cones of each retina, to transmit nerve impulses and organize them into useful messages, recognizable forms, and meaningful scenes?

      A basic organizing principle of the visual system is that of a hierarchy of information: a relatively large number of specialized cells at each stage supply information to a smaller number of cells at the next stage, which in turn have their own specialized function. The retinal rods are most attuned to dim light, the cones to bright light . Both rods and cones transmit impulses to another layer of the retina, which sends signals through the third layer to the many neuronal fibers that make up the optic nerve.

      Each cell in the third layer that supplies the optic nerve already represents the confluence of signals from thousands of rods and cones over about 1 square millimeter of the retina. The square millimeter thus covered is called the receptive field of that cell. The optic nerve in turn supplies a large amount of pooled information to the lateral geniculate nucleus, which then relays signals to the primary visual cortex.

      The Brain And The Eye

      A Look at the Brain

      The eye works like a camera. The iris and the pupil control how much light to let into the back of the eye, much like the shutter of a camera. When it is very dark, our pupils get bigger, letting in more light when it is very bright our irises constrict, letting in very little light.

      The lens of the eye, like the lens of a camera, helps us to focus. But just as a camera uses mirrors and other mechanical devices to focus, we rely on eyeglasses and contact lenses to help us to see more clearly.

      The focus light rays are then directed to the back of the eye, on to the retina, which acts like the film in a camera. The cells in the retina absorb and convert the light to electrochemical impulses which are transferred along the optic nerve to the brain. The brain is instrumental in helping us see as it translates the image into something we can understand.

      The eye may be small, but it is one of the most amazing parts of your body. To better understand it, it helps to understand the different parts and what they do.

      ChoroidA layer with blood vessels that lines the back of the eye and is between the retina and the sclera .

      Ciliary BodyThe muscle structure behind the iris, which focuses the lens.

      CorneaThe very front of the eye that is clear to help focus light into the eye. Corrective laser surgery reshapes the cornea, changing the focus to increase sharpness and/or clarity.

      FoveaThe center of the macula which provides the sharp vision.

      ScleraThe white outer coating of the eyeball.

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      Seeing The Patterns In Visual Signals

      How does the brain coordinate such a flood of information from the eyes? This is a job for the cortexspecifically, the intermediate layers of the primary visual cortex. Signals from the optic nerve pass through the lateral geniculate to the intermediate layers of the cortex, where any given cell receives impulses from either the right or the left eye. Small groups of cells responsive to one eye or the other form a striped pattern in the cortex, which can be made visible by injecting one eye of an anesthetized animal with a radioactive amino acid, exposing it to light, and developing the emitted radiation as a photographic image. The stripes, like the cell groups that respond to a particular orientation of line, are about half a millimeter in diameter.

      Vision In The Brain: Is It True Or False That Vision Rules The Brain

      This post explores the scientific data behind often-quoted stats around visual thinking, visual learning, and the use of images in learning. Youll learn what we know about how much what we see impacts what we think.

      At ImageThink, we know firsthand the power that visuals have when it comes to boosting cognitive power. Since 2009, we have used graphic facilitation and live illustration to empower strategy sessions, clarify complexity, and spark creative problem solving for Fortune 50 companies the world over.

      But dont take our word for it. In this series of posts, were exploring the scientific data behind often-quoted stats regarding visual thinking, visual learning, and the power of images in cognitive development. You can read more about it

      A pretty strong case has been made for visuals as learning and teaching tools. Lets look at the actual makeup of our brain tissues and find out what percentage of the brain is used for vision.

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