Category Archives: Neuroscience

Your-Brain-On-Drugs

Your brain on your brain on

Researchers at the University of Parody today published new findings on the effects of unimaginative neuroscience article titles on anxiety, depression, and the desire to throw shoes at your computer screen.

The research was inspired by the fact that every single time — EVERY SINGLE TIME — a study involving brain imaging is conducted on a new topic, articles pop up all over the internet with “Your Brain On” headlines. “Your Brain on Love.” “Your Brain on Literature.” “Your Brain on… whatever.”

Researchers split participants into two groups. The first was presented with a series of “Your Brain On” neuroscience article headlines, while the control group was repeatedly beaten with a stick.

Compared to the “Beatings” group, the “Headlines” group reported increased anxiety, depression and decreased will to live, however, this may be because the control group was told they had better report high scores or else the beatings would continue at considerably higher intensity.

The paper ends by indicating that science journalists should drop this article structure immediately in the name of all that is holy and righteous, and also that watching the following is advisable to all readers and writers of neuroscience.

Bill Hicks, “Your brain on drugs.” (not safe for work)

P.S. The source of the problem:

mind-body-problem

Where is my mind? Is the materialistic model of reality incorrect?

My belief about the nature of reality is that the only “thing” that exists is matter. That is, there is no soul, no heaven and no hell. Effects aren’t caused without an interaction with different pieces of matter, and consciousness exists within the confines of the physical head that gives rise to it.

However, although I used to be extremely firm in this position, now I am less sure, because of one question. I don’t know how to answer this from a materialist perspective. Maybe there’s just a really simple answer that I’m missing, but I’ve spoken to many people on this and no one has given it to me. Maybe you can. So here’s the question.

Where is the cat?

“HAHAHA puny humans you will never find me. (Photo by Tambako the Jaguar

I can make a picture of a cat in my head; I can close my mind and think of it. So I’m perceiving this image of a cat.

Where is the image? Where is the cat?

I first heard this question (well, I added the cat part myself) in a lecture on the mind/body problem, and my initial answer is that the cat is simply a 1:1 correlate of certain neurological activity in the brain. That is, if you open up my head you won’t see a picture of a cat, but you’d see something that’s the equivalent of it, sort of like the dots and dashes of Morse code are not English characters, but they are equivalents of them. From a materialistic perspective, you’d theoretically be able to interpret the activity in my brain through some technology, and recreate the image of the cat that I am picturing on a screen.

In fact, we’re past theorising on this, as a famous experiment last year that was widely reported as “Mind Reading” in the media demonstrated. Here’s what they did:

1) Measured brain activity as someone watched a load of YouTube videos
2) Linked up the brain imaging data with the image on the screen, creating a sort of database whereby such-and-such brain activity relates to, say, a red object in the middle of the screen, such-and-such relates to certain shape moving to the left, and so on. I’m probably over-simplifying, but that’s the gist.
3) Get the same person to watch a new set of YouTube videos, again while in the scanner measuring brain activity.
4) Use the database created in step 2 to predict what the person was seeing in step 3.

Here’s how the reconstructions compared to the original videos:

It’s important to note that the brain may not code imagined images in the same way as those you see with your own eyes, and also that each person’s brain will likely code the image of the cat in different ways (hence the need for steps 1 and 2), but, since all of the activity of the mind is thought to have a direct neural correlate, the principle is the same.

So when I was asked “where” my mental image of the cat is, that’s why I responded in this way — the image is located in the brain – it’s just in a different format.

But really, I’m not satisfied with that answer. Because in my mind I can see (well maybe not see, but certainly perceive) the cat; not the equivalent neural ‘code’, but the actual cat. I know where the neural code is, but I don’t know where the cat is.

I can’t think how the materialistic model can explain where the cat is. Doesn’t this mean then that there’s more to reality than the purely materialistic? That the materialistic model is incomplete? What am I missing?

To use a computer analogy, the words you are reading now (hello!) are represented in a chip in a computer as a string of 0’s and 1’s. That’s like the neural code in your brain. But the actual words are represented on the screen in front of your eyes. What’s the equivalent of the screen in the case of the cat? Where is it?

I’m actually asking this to you – do you know where the cat is? Am I making a simple mistake? Please leave a comment and help me out!

Where is reality?

That’s probably enough for one day, but just to take this one step further; we know that what we see is not the world. The image we see is a mental construction of the world, and psychology has identified numerous examples of how we each see the world a little differently. An obvious example is colour-blindedness. Since the brain is constructing the world we see around us, and if we assume that the neural code and the image are different things… where is reality?

Ref:

Nishimoto S, Vu AT, Naselaris T, Benjamini Y, Yu B, & Gallant JL (2011). Reconstructing visual experiences from brain activity evoked by natural movies. Current biology : CB, 21 (19), 1641-6 PMID: 21945275

The neuroscience of laughter – 5 minute mini-lecture by Sophie Scott

Here’s a short and interesting introduction to the topic of laughter by UCL professor Sophie Scott. It’s interesting that laughter seems to have an evolutionary heritage that goes way way back, since other animals appear to do it too, but more interesting to me is what goes on in the brain when we hear laughter, and how the brain seems to prepare for it. I’ll let you watch the video to get the rest, it’s only five minutes and time well spent if the title catches your interest at all.

There you have it. If you hear of any “rat-tickler” jobs going, let me know.

tv

Neuroplasticity and Television

Here’s an interesting thought for you. We could go into this more deeply, and maybe we will in the future, but just for the moment, ponder this. If you do anything regularly and consistently, the brain will change, actually change physically, anatomically, in structure. For example, in violinists the part of the brain linked to the left hand is bigger. Because violinists practice so much, the brain adapts to allow them to do this activity better, more efficiently. The neurological implications of consistent, regular repetition of violin playing are massive – neurons thicken, allowing more electricity and therefore stronger signals to pass through them, and more connections are made between neurons; all with the end result of making the violinist better at playing the violin.

How much time do you spend watching television? What are the neurological implications of this? What is the end result of the synaptical connections being made, day after day? What is it making you better at?

PET_scan

Meditation is associated with changes in the physical structure of the brain

In this post, I mentioned some interesting studies where neuroscientists put Buddhist monks into brain scanners, trying to find out what effect meditation has on the brain. They found some interesting results in terms of brain activity. If you throw neuroplasticity into the mix too, you’d expect some structural differences too. A study led by Sara Lazar looked into just that.

I’ve mentioned my thoughts on neuroscience and positive psychology previously. My key point is that, since neuroplasticity is a given these days, it’s not all that impressive to demonstrate changes in the brain as a result of consistent practice of a given activity. But that doesn’t mean it’s not an important study to do. The key questions are: what changes, how much, and does this fit in with other results and theory?

Twenty experienced meditators (had been one at least one retreat, practice 4 hours a week on average), were compared to a matched control group (by age, sex, race, and years of education). So note here that we don’t have random assignment, but we’ve got the next best thing if we want to study experienced meditators right now.

What happened?

Cortical thickness was compared between the two groups. Over the whole brain, there was no difference, meaning the changes were limited to a specific area. The areas were related to somatosensory, auditory, and interoceptive processing. If you want the specific brain regions, here they are:

  • A region of the right anterior insula
  • The right middle and superior frontal sulci (Brodmann areas 9 and 10, roughly)
  • The left superior temporal gyrus (auditory cortex)
  • A small region in the central sulcus

Also, normal age-related decreases in Brodmann areas 9/10 were seen in the control group but not the meditation group. In other words, meditation potentially helps prevent age-related deterioration in the brain!

Of course, this is a correlation study, and when two things are measured at the same time, it’s impossible to say what is the cause and what is the effect. Maybe people with enhanced cortical thickness tend to be drawn to meditation, rather than the other way around? It’s certainly possible, but as the authors note, if that were true you might expect greater cortical thickness overall, which wasn’t found here.

Meditation gives a double-whammy when it comes to making structural changes in the brain. Firstly, there is the control of attention during a consistent practice schedule. Secondly, the relaxed state of the body appears to facilitate cortical plasticity, at least in the auditory areas according to one study. This is comparable to the idea that sleep aids learning, study breaks aid recall, and so on.

That the structural changes were consistent with the brain areas associated with the techniques being practised, and that these changes may stave off age-related cortical decline, is encouraging. Presumably, different types of mental exercise would have effects on the brain areas related to them, and you could devise a routine aimed at the faculties you expect you’ll most need in your old age.

Ref:

Lazar SW, Kerr C, Wasserman RH, Gray JR, Greve D, Treadway MT, McGarvey M, Quinn BT, Dusek JA, Benson H, Rauch SL, Moore CI, Fischl B. Meditation experience is associated with increased cortical thickness. NeuroReport, 2005; 16: 1893-1897.