That Neuroscience Guy - Neuroscience Bites-Neglect

Episode Date: February 2, 2023

Sometimes, after a stroke or head trauma, patients experience deficits in perception of things in one side of their vision. In today's Neuroscience Bite, we discuss the neuroscience behind neglect. 

Hi, my name is Olof Krogolson and I'm a neuroscientist at the University of Victoria. In my spare time, I'm that neuroscience guy. Welcome to another Neuroscience Byte. Today I'm going to talk quickly about neglect. It came up in one of my classes the other day and a student asked me about neglect. And when people hear about neglect, or as it's called, hemispatial neglect, I think you might take it the wrong way if you don't think about it in terms of neuroscience. I'm going to tell you a bit about how neglect actually can be spotted. I've got a friend who's a nurse, and she was saying that she had a patient and the patient was lying in bed and they sat him up and they brought him his dinner. And when she came back to check on his dinner,

she found that he'd only eaten the food on the right-hand side of his plate. He hadn't touched any of the food on the left-hand side of the plate. And she told me that, you know, with another patient, she'd found that the old lady had been given flowers, and she said to the old lady, you know, how do you like the flowers? And the old lady said, what flowers? I can't see any flowers. And interestingly enough, those flowers were on the left-hand side of the room. So what is neglect or hemispatial neglect? Well, sometimes after a stroke or brain trauma, people with damage to the right parietal cortex experience neglect. And neglect is an attentional phenomenon. It basically means that you sort of aren't paying attention to left visual space.

So if you take your nose and you sort of draw a line straight out, right visual space is to the right, obviously enough, and left visual space is to the left. And people with neglect, they can see what's on the left-hand side, but they just don't pay attention to it. So in the case of eating the food on the plate, they just don't eat the food on the left-hand side of the plate because they're just not paying attention to it. And they can pay attention to the food on the right-hand side of the plate. So they eat it. And same with the flour example that I used. They can see that the flour is in the left-hand side of the room, but they're just not paying attention to it. So they tend to ignore it. And that's neglect. Clinically, when you test for neglect, you can do some interesting things. And I'd encourage you to go on Google Images and search for this. And I'll do a

quick blog post about it and just put up some images. But if you ask someone with neglect to draw a clock, this is a classic thing to do. They might get the circle part right, but you'll find that they'll put the numbers from 12 all the way around just on the right-hand side of the clock. Or if you ask them to draw a house or a flower, they might only draw the right-hand side of the house or the flower. And another classic test is you give them what's called a line bisection test. And what that means is there's a bunch of horizontal lines on a page, and you ask them just to bisect or put a vertical line through every horizontal line. And what you find is people with neglect only bisect the lines on the right-hand side of the page. Now, neglect is a continuum.

Mild neglect might mean that you do attend to things in the left hemisphere, you just don't do it as often. do attend to things in the left hemisphere. You just don't do it as often. Whereas extreme neglect, which I'll talk about in the next bite next week, means you basically have an indifference to the left-hand side of space, which would be drawing half the clock or bisecting half the lines.

And just in terms of how these things occur, neglect is actually quite common post-stroke. It's something that you see a lot in the hospital, but most times it tends to go away over time. Anyway, that's a little bit on neglect, a little bite, if you will. Don't forget the website, thatneuroscienceguy.com, links to our Etsy store, support us on Patreon, send us ideas via Twitter. Thanks for those of you that do. You can follow me at thatneuroscienceguy and DM me. And of course, thank you for listening to

the podcast. Please subscribe. My name is Olof Kregolsen and I'm that neuroscience guy. I'll see you in a couple of days for another full episode of the podcast.