Today it is my pleasure to welcome author Michael Tranter, PhD and his popular science book A Million Things To Ask A Neuroscientist
A Million Things To Ask A Neuroscientist answers some of the most asked questions about the brain, making the science fun and accessible to everyone. Inside, you will journey through some of the most interesting and strange things that our brain does every single day.
Have you always wanted to know just what a memory actually is, or why we dream? What is our consciousness? Why do some people seem to ‘click’ with others? And can our brain really multi-task?
How can you be blind but still see?
(The brain is amazing, that’s how!)
Dr. Tranter’s book looks amazing to me, but I was curious what single piece of information about the brain he thought people would find to be the most surprising. I got the chance to ask him that questions and here is his … well … amazing answer.
At the back of the brain we have the occipital lobe. This region receives images from our eyes and optic nerves and decides what we are seeing before sending that information to other parts of our brain to determine how to react. So, if we see an adorable fluffy dog, the light reflected from that dog travels to our retina at the back of our eye, along the optic nerve and to the occipital lobe, where it is processed. Other areas then interpret the meaning and decide what the emotional response should be, resulting in a very excited ‘Aww, a cute puppy – I like this, I feel happy!’
However, damage to the occipital lobe, for example, through trauma, a brain tumour or a stroke, can result in the images of the cute puppy arriving at the visual areas safely, but not being processed or transmitted to other areas of our brain, and hence, we become blind. This is a little different to instances where the eyes or optic nerve don’t function. This additional blindness is termed cortical blindness – essentially, blindness in the brain. You may be asking why I am talking about cute puppies and blindness. Well, because in some people with cortical blindness, even though they can’t see particular objects, their subconscious brain still perceives them. This means a person can interact with something even if they don’t actually see it. Let’s use another example. Say you want to walk across the room to the doorway, but there is a chair in your path. Under normal circumstances, you would see the chair and walk around it. A person with blindsight would also walk across the room and avoid the chair, yet they would not actively see that there is a chair in the room. They simply avoid it but do not fully understand why.
This strange phenomenon was first documented in the 1974 research by Lawrence Weiskrantz and has since been recorded in all manner of situations. A person may catch a ball in mid-air without ever seeing it, for example, but perhaps the most interesting study shows how it is possible to identify facial emotions and even mirror those same emotions in your own face, without ever being consciously aware of seeing any facial expressions.
Blindsight has been rigorously tested in many experimental settings, and as such, neuroscientists think they have an explanation. Firstly, the fact that some people with cortical blindness experience the phenomenon of blindsight may be because the superior colliculus – an area of the brain important in visual orientation – is preserved. Although we don’t yet fully appreciate the full function of the superior colliculus, we do know that this area receives information about what we see and converts it into signals that initiate an appropriate movement. To help explain this, imagine sitting down and watching a racing car drive past. Our eyes and head would instinctively follow the car as we track its movements. This is the responsibility of the superior colliculus, to instinctively monitor the environment and decide how to move our body.
The current hypothesis for blindsight states that as the brain senses damage to the occipital lobe, it starts to rewire itself to bypass the visual areas. The person may never entirely regain normal vision, but they may still be capable of living a normal life. Some neuroscientists suggest that this is a process by which the brain reverts back to a more basic form of vision, and one that is seen in animals who naturally lack the advanced visual areas of a human brain.
So, there you have it. That is how you can be blind, but your brain can still see, pretty amazing right?
About the Author
Dr Mike Tranter is from the North of England and studied how drugs work in our body, but it wasn’t long before he found his true calling as a neuroscientist. After a PhD in neuroscience, he spent years in research labs all over the world, studying how the brain works. Although, it is his prominent rise as a science communicator, opening up the world of neuroscience to everybody, that he enjoys the most.
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Yes, there is a giveaway
The author will be awarding a $20 Amazon/BN gift card to a randomly drawn winner via rafflecopter during the tour.
This post is part of a tour sponsored by Goddess Fish. Check out all the other tour stops. If you drop by each of these and comment, you will greatly increase your chances of winning.
My Favorite Excerpt
Have you ever been standing at the top of a tall building or cliff edge and had a sudden but brief urge to jump? You have no real thought of actually doing it, and you are not depressed, suicidal, or otherwise distressed, but that urge appears nonetheless. As it turns out, neuroscience has a name for such an occurrence, high places phenomenon, sometimes termed the call to the void, and it is actually very normal and common. There are also reports of impulses to jump in front of a train, stick a hand in a fire, or turn a steering wheel into traffic. Thankfully, the person generally doesn’t follow through, and although most accounts of this phenomenon are anecdotal, there is one team of scientists in Florida, USA, who decided to take another look. The research team asked 431 students about such episodes in their personal lives, and a surprising 55% acknowledged that they have experienced them at some stage in their lives.
Science has revealed to us that high place phenomenon is possibly the result of a split-second delay between two opposing brain signals. One signal is based on our survival instinct that notices danger and tells us that we should avoid it, such as falling from a great height, or a train hitting us in the face. Another signal coming from our more logical brain tells us that we are relatively safe where we are, and there is no real threat to our survival. The resulting signals are interpreted by our brain – now somewhat confused, for it to relay this rather bizarre message and we experience the high place phenomenon. So, if you ever have a sudden impulse to jump off the top of Mount Everest, just remember that it is normal, but please don’t do it anyway.
Personal note from your blogging host: this has happened to me many times and I was so glad to read that it is a normal phenomenon! Wow. This may be the most useful excerpt I’ve ever posted!
Michael Tranter, PhD — we appreciate your sharing your book A Million Things To Ask A Neuroscientist with us! Best of luck with sales, and with all of your future writing.