The first time I remember experiencing the strange phenomena of blindsight was about 6 years after my brain haemorrhage. My then boyfriend, now husband and I were driving to the beach for a weekend away from the city. I was in the passenger seat and he was on my right in the driver's seat. We were sharing a can of coke after just stopping to fill the car up at the petrol station. After passing the coke to him for his turn to have a drink I got caught up in a daydream while staring at the road ahead. All of a sudden, I heard him ask "how did you do that?". I was confused and asked, "how did I do what?", I had no idea what he was talking about. The conversation then continued, "you reached out and took the coke off me without even looking to your right! How did you know I was passing it back to you?". I was completely baffled! Firstly, I didn't remember doing this and secondly, I had no idea how I had seen that he was passing the coke back to me! We joked about my daydream and being in auto pilot mode and moved onto talking about something else.
I may have experienced blindsight before this, but I had never before registered being able to 'see' something in my right visual field, where I technically shouldn't be able to see anything due to not having a left occipital lobe (the part of the brain responsible for seeing information in your right visual field). Since this experience of 'seeing' the coke can didn't make any sense to me, I completely ignored it and promptly forgot about it. I finally recalled the incident another 10 years later after hearing a conference presentation where I was introduced to the phenomenon of blindsight. Blindsight is the ability to respond to visual stimuli that is not consciously seen due to injury or damage in the occipital lobes. In learning this, I realised that I had been experiencing blindsight for a long time, but had been completely ignoring it, as I thought I was just imagining it. I also thought people would think I was crazy if I tried to explain to them that I was 'seeing' without actually seeing.
I decided to see if I really did have blindsight and introduced myself to the presenter who had shared the information during his presentation. Some basic testing of getting me to look straight away and seeing if I could accurately point to a finger moving in my blind visual field (which I did around 90% of the time), confirmed that I mostly likely had a degree of blindsight. I was then given a short tutorial on how I could use this blindsight to my advantage and turn what was an unconscious visual function into a more conscious function, which would possibly allow me to see more in my right visual field. Delighted at the prospect of improving my visual fields after being told that it would never improve 17 years earlier, I was determined to give it a try and make it work. A home grown blindsight training programme was born!
The first step was to test my ability further. For this, I tried an activity that had been suggested to during my tutorial after the conference presentation. This involved standing still, looking straight ahead and nodding my head up and down (to allow for my visual system to use the unconscious process of seeing movement), while someone stood slightly to my right holding a piece of paper with a letter on it. To my amazement, I correctly guessed the letter 3 out of 4 times even though I didn't actually 'see' it. After that, I took every opportunity to further challenge my visual abilities. Whenever traveling in the front passenger seat of the car, I took every opportunity to try and detect the driver's movement while looking straight ahead. When going for walks, I tried to detect the exact moment cyclists, runners or other walkers passed me on my right side (I always had headphones in so couldn't hear them coming). But probably the most entertaining test was trying to detect our black cat sneaking up on me on my right side. She did this regularly (especially while I was watching TV), which earned her the nickname Slinky Malinki! When I 'saw' something on my right, I didn't actually see an image, the thought would just pop into my head - the cat is on my right, or there is someone there on my right. And every time I 'saw' something on my right without actually seeing it, I would yell out with excitement - I saw that! Which turned out to be quite confronting for the unsuspecting strangers I was so excited to see! I probably should take this opportunity to apologise to the lovely air hostess who I greeted by yelling 'I can see you!' when she appeared on my right side to ask if I wanted tea or coffee during a short flight to Wellington.
But no need to just take my word for it that I am seeing more in my right visual field - the proof is in the pudding so to speak. When I had my visual fields tested a couple of years after starting my home grown blindsight training programme, the results were startling and showed that I was indeed seeing more right visual field than when the test had been 5 years earlier - proving that it is possible to improve visual fields, even 20 years after the incident that caused the damage and the vision impairment.
For more information please see our page Homonymous Hemianopia (New Vision in Absent Visual Field) Paper.
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