Yesterday, I experienced for the first time one of the "joys" that even the most savvy bloggers cannot escape: after spending a good 20 minutes writing a new blog and uploading some great pics, my internet browser gives me an error and all is lost in cyberspace.
Now that I've had an evening to regroup and unleash my anger upon innocent animals (just kidding!!!), I'm going to try and recreate my piece of mind from yeasterday. I thought it would be useful to share some of the work I have been doing while studying and working towards my master's degree at York University (since it's also kind of the reason I started this blog). Basically, my labmates and I have been interested in looking at the interactions of our different sensory systems (specifically vision + touch) and how they combine information to form a coherent percpetion of the world around us. Even more interesting, though, is when we interrupt one of these sensory inputs (i.e., blocking vision with a black contact lens)- what we have found is that subjects report wierd sensory perceptions, charatcerised as numbness, tingling, heaviness, sagging or drooping of the eyelid of the blocked eye, that- within seconds of putting in the contact lens, and which disappear completely within seconds of removing the contact lens.
Why would vision affect touch? Well, there are parts of our brain that are responsible for combining these separate 'streams' of information, which is just as important as perceiving each of these modalities separately. Think about this example: have you ever watched a movie or tv show where the sound and picture are not synchronised? Even if the sound is delayed (or advanced) by mere milliseconds, our human brain compter machine is incredibly good at picking up these minute 'asynchronies' or 'inconguities', and also at trying to make sense of why they occur. We know that movies and tv employ moving pictures and audio tracks that are layered to play simultaneously to play a moving, talking image. So we are also able to cognitively make sense of why they may be 'off'. Similarly, when only one eye suddenly experiences a loss of vision, but we can still see normally with our other eye, our brains try to make sense of the sudden binocular disparity. We hypothesize that the unusual facial sensations (or paresthesias if you're a fancy-pants) that result from insertion of our black contact lens are due to complex processes in brain regions that combine visual and touch information: when one of these incoming 'streams' (vision) is suddenly cut off, these regions send signals down the other stream (touch) to signal that something must be blocking our vision. Because contact lenses don't provide tactile feedback on our faces like a hand or eye patch would but sit rather comfortably or unnoticeably on our corneas, our brains need to account for this sudden blindness, and attribute it to a malfunction of the facial structures surrounding the freshly-blind eye, resulting in 'illusory', 'induced', or 'self-generated' paresthesias.
There are lots of example of cool sensory illusions like this that involve vision and touch, as well as many that involve other sensory streams, and I'll likely post some examples in the future. For now, here's a look at my findings as presented recently at the Society for Neuroscience conference I attended in San Diego, California, along with some lab pics. So now that I can make people's faces numb, if only I could make my boyfriend's hands numb so he would put down the Playstation controller and call me instead of playing Black Ops.....
p.
Now that I've had an evening to regroup and unleash my anger upon innocent animals (just kidding!!!), I'm going to try and recreate my piece of mind from yeasterday. I thought it would be useful to share some of the work I have been doing while studying and working towards my master's degree at York University (since it's also kind of the reason I started this blog). Basically, my labmates and I have been interested in looking at the interactions of our different sensory systems (specifically vision + touch) and how they combine information to form a coherent percpetion of the world around us. Even more interesting, though, is when we interrupt one of these sensory inputs (i.e., blocking vision with a black contact lens)- what we have found is that subjects report wierd sensory perceptions, charatcerised as numbness, tingling, heaviness, sagging or drooping of the eyelid of the blocked eye, that- within seconds of putting in the contact lens, and which disappear completely within seconds of removing the contact lens.
Why would vision affect touch? Well, there are parts of our brain that are responsible for combining these separate 'streams' of information, which is just as important as perceiving each of these modalities separately. Think about this example: have you ever watched a movie or tv show where the sound and picture are not synchronised? Even if the sound is delayed (or advanced) by mere milliseconds, our human brain compter machine is incredibly good at picking up these minute 'asynchronies' or 'inconguities', and also at trying to make sense of why they occur. We know that movies and tv employ moving pictures and audio tracks that are layered to play simultaneously to play a moving, talking image. So we are also able to cognitively make sense of why they may be 'off'. Similarly, when only one eye suddenly experiences a loss of vision, but we can still see normally with our other eye, our brains try to make sense of the sudden binocular disparity. We hypothesize that the unusual facial sensations (or paresthesias if you're a fancy-pants) that result from insertion of our black contact lens are due to complex processes in brain regions that combine visual and touch information: when one of these incoming 'streams' (vision) is suddenly cut off, these regions send signals down the other stream (touch) to signal that something must be blocking our vision. Because contact lenses don't provide tactile feedback on our faces like a hand or eye patch would but sit rather comfortably or unnoticeably on our corneas, our brains need to account for this sudden blindness, and attribute it to a malfunction of the facial structures surrounding the freshly-blind eye, resulting in 'illusory', 'induced', or 'self-generated' paresthesias.
There are lots of example of cool sensory illusions like this that involve vision and touch, as well as many that involve other sensory streams, and I'll likely post some examples in the future. For now, here's a look at my findings as presented recently at the Society for Neuroscience conference I attended in San Diego, California, along with some lab pics. So now that I can make people's faces numb, if only I could make my boyfriend's hands numb so he would put down the Playstation controller and call me instead of playing Black Ops.....
p.
Di Noto, PM, & DeSouza, JFX. (2010). A multisensory visuotactile illusion induced by monocular occlusion with a black contact lens: tactile thresholds. Abstracts Society for Neuroscience: 579.1/RR3.
Outdoor lunches in November rock!
With other members of the York U Neuroscience Graduate Diploma Program, putting on for our city on the dancefloor.
