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Archive for the ‘Neurology’ Category

I’ve read two of Daniel Dennett’s books, and while I enjoyed them at the time I find myself unable to remember what they were about, what their arguments were, or indeed any memorable passages. Maybe it’s just me, but I remember almost nothing from “Freedom Evolves”.

I’ve just watched one of Dennett’s TED talks, having been pointed there by 3quarksdaily. The title of the talk is “The Illusion of Consciousness”. Maybe I’m being thick, but I after 20 minutes I’m left with this question: what does any of this have to do with consciousness at all, let alone showing it to be an illusion? Before I move on, I should stress that I’m no kind of philosopher of mind or neuroscientist. I’m not even particularly well-read in the popular literature of these fields. Comments, please!

What I’m going to try to do today is to shake your confidence … that you know your own, inner-most mind, that you are, yourselves, authoritative about your own consciousness. …

Somehow we have to explain how, when you put together teams, armies, battalions, of hundreds of millions of little robotic unconscious cells … the result is colour, content, ideas, memories, history. And somehow all that concept [content?] of consciousness is accomplished by the busy activity of those hoards of neurons.

So we’re off to a good start. The hard problem of consciousness is to explain why certain collections of cells become conscious at all. Dennett particularly wants to question whether we really know our own conscious selves. Good. What is his method?

How many of you here, if some smart alec starts telling you how a particular magic trick is done, want to block your ears and say, “I don’t want to know. Don’t take the thrill of it away. I’d rather be mystified. Don’t tell me the answer.” A lot of people feel that way about consciousness, I’ve discovered. I’m sorry if I impose some clarity, some understanding on you. You better leave now if you don’t want to know these tricks.

Method: condescension. He’s going to smug those illusions right out of us.

The example is wrong. I don’t want you to tell me how a magic trick is done for the same reason I don’t want the stranger on the train to lean over and give me crossword answers. It’s a puzzle. The fun is thinking about it yourself. No one says “I don’t want the crossword answers. I just want the mystery of the empty squares.”

Note the implicit ad hominem. Anyone who disagrees with Dennett is weak-minded, a blissful ignoramus. Actually, those who criticised books such a Dennett’s “Consciousness Explained” usually complained that it failed to explain consciousness.

I’m not going to explain it all to you. … You know the sawing the lady in half trick? The philosopher says “I’m going to explain to you how that’s done. You see  – the magician doesn’t really saw the lady in half. He merely makes you think that he does.” How does he do that? “Oh, that’s not my department”.

This is all very amusing, and delivered with a twinkle in the eye. But the message of the metaphor is this: brace yourself for some bald assertion. I’ll tell you what follows from my assumptions, but don’t expect any evidence.

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I’ve hit something of a purple patch with books of late, so its time for some brief book reviews. Most of these will concern topics outside my area of expertise, and so I can’t offer anything like a rigorous critique.

My first book is “The Decisive Moment”, by Jonah Lehrer. I blasted through this book in a few evenings back at the hotel during a conference. It made very enjoyable reading. In particular, the author makes very good use of narrative – one is enticed into each chapter with a variety of case studies. Chapter six’s account of the serial killer John Wayne Gacy, for example, makes for compulsive reading.

The theme of the book that most resonated with me was the importance of emotion to rationality. Emotions are often thought of as irrational – we see this in expressions like “I let my emotions get the better of me” and the connotations of objectivity attached to the adjective “dispassionate”. I think this goes back at least to Plato. Lehrer, however, shows that emotions do have an important role to play in decision making. They allow for fast, unconscious decisions to be made and implemented. Those who due to brain injuries have seemingly lost the ability to form emotions find that even the smallest decisions – chicken or beef? – paralyse them like Buridan’s ass. Conscious thought can actually lead to worse decisions, as in the case of would-be jam experts (page 138). Those who simply tasted a selection of jams and reported which ones they liked best broadly agreed with the opinions of food experts. Those asked to analyse their impressions via written questionnaires suddenly preferred inferior jams. It’s a beautiful little parable, and Lehrer’s discussion of such examples is both nuanced and insightful.

The book is both practical and philosophical, ranging from how to make better decisions to the most contrived ethical conundrums. Experimental findings and anecdotes are weaved seamlessly. I read the book over a year ago, but looking back over it now makes me want to read it again.

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Here’s a great little contribution appearing in this week’s edition of our sister journal:

The ability to determine the structure of matter in three dimensions has profoundly advanced our understanding of nature… Here we present a 3D imaging modality, termed ankylography (derived from the Greek words ankylos meaning ‘curved’ and graphein meaning ‘writing’), which under certain circumstances enables complete 3D structure determination from a single exposure using a monochromatic incident beam.

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A few quotes to get you thinking …

Pat Pattison: Professor of Poetry and Lyric writing at the Berklee College of Music in Boston, author of “Writing Better Lyrics”:

The time to start [songwriting] is the first thing in the morning, even before coffee. Sit down and give it a full ten minutes – but no more.

Barry Green, in his book “The Inner Game Of Music”:

My fourteen-year-old cousin Dana … tells me that she plays piano best when she has just rolled out of bed in the morning or is exhausted at the end of the day … It seemed amazing to both of us that Dana was able to perform much better when she was barely awake … Other musicians, young and old, have told me that they perform best when they are relaxed, slightly ill [or] tired.

Songwriter Mike Read, in “The Secrets of Songwriting” by Susan Tucker; asked “Is there a certain time of the day you like to write?”:

… I have this little ritual. I love that smell of the first cup of coffee. I love the early morning … I love getting up early, at six o’clock.

It seems that we are most creative in the morning, when we haven’t woken up properly. Is there any scientific evidence to back up this anecdotal evidence?

On December 2, 2007, New Scientist ran an article titled “The Other You”. The article mentions the work of Colin Martindale of the University of Maine in Orono, which is now three decades old. He used an electroencephalogram (EEG) to monitor the brain activity of a creative mind.

He found that there were two distinct stages of brain activity. During the initial “inspiration” stage, the brain is remarkably quiet. Brain activity is dominated by alpha waves, indicating a very low cortical arousal. The second stage is called the “elaboration” stage, and is characterised by more activity, especially in the cortex. It is probably associated with the conscious analysis of ideas. People with the greatest difference in brain activity between these two stages were the most creative.

The point of interest to us is that brain activity during the inspiration stage is very similar to brain activity during dream sleep and relaxation. Jordan Peterson, of the University of Toronto, Canada, believes that creativity involves the overflow of subconscious information into consciousness. Thus, to tap the rich mental resources of the subconscious, it is best to catch your conscious mind while it is still half asleep.

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In music, there is a chord known as the “Jimi Hendrix chord”. For those who know about these things, it’s a dominant 7 #9 chord – e.g. C7#9 contains the notes C E G Bb D#. The dissonance between the E and the D# (the major and minor third in C respectively) creates the gritty, edgy, crunchy rock sound that Hendrix uses in Foxy Lady and Purple Haze.

There is a story, possibly an urban legend, that Purple Haze is so named because the Jimi Hendrix chord in its introduction made Hendrix see a purple haze. Other theories invoke copious amounts of LSD and marijuana, but it is the triggering of a purple haze that I want to focus on.

This phenomenon, of one sensory experience involuntarily triggering a second, usually unrelated sensory experience, is known as synesthesia. It is a neurological condition, and appears in a variety of forms. For example, some synesthetes (as they are called) associate letters and numbers with colours – for example, a black 5 written on a page is seen to be green; a 2 seen to be red.

At first glance, the condition doesn’t seem very interesting. Most people would connect the word ‘sunset’ with an orange-red colour for the following reason:

  • First, the word “sunset” connects with the concept of a sunset.
  • Next, the concept of a sunset connects with a mental picture of a sunset.
  • Finally, the mental picture of the sunset fills the mind with an orange-red glow.

The mind does all this in an instant, so that the word “sunset” and the colour “orange-red” link seamlessly.

We might postulate that synesthesia involves the same sort of connections, albeit a bit less obvious. For example, the number 2 could trigger a childhood memory of a refrigerator magnet ‘2’ that happened to be red. As time goes by, the connection between the number 2 and the colour red remains even when the fridge magnet is forgotten.

But synesthesia is more than simply association – the number 2 doesn’t just remind them of the colour red. When synesthetes see a black 2, they will tell you that it “really is red”. But is there any way to test how real this mental response is?

In 2001, Ramachandran and Hubbard performed the following ingenious experiment. (See the Wikipedia article on synesthesia for more details.) They presented synesthetes and non-synesthetes with displays composed of a number of 5s, with some 2s embedded among the 5s. These 2s could make up one of four shapes; square, diamond, rectangle or triangle – see the diagram below:

Subjects were asked to identify the hidden shape. If recognising the number triggered a concept that triggered a colour, then the colours wouldn’t appear until after the number was recognised. Thus, if synesthesia is just a subjective, mental connection, then it won’t help a synesthete to find the hidden 2’s.

The results were astounding. Non-synesthetes took about 20 seconds to find the shape; synesthetes took about a second.

How do you explain that? Seeing something that isn’t there is one thing, but having it improve your ability to discern shapes is something else. Its like having an imaginary friend who actually helps with the laundry. (This is why synesthesia isn’t usually classified as a neurological condition, because it is often advantageous to the “sufferer”.) Most explanations involve rejecting the linear processing of sense data we invoked previously. Some researchers have suggested that increased cross-talk between different regions of the brain that are specialized for different functions could explain it.

What if you could train your mind to use synesthesia? What if a piano student who struggles to read music could be taught to see each note on the page as a different colour? Could children be taught to see harmful objects as red and harmless ones as blue? What if you saw interesting blog posts as red, and boring ones as blue?

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