In one eye and out the other
6th August 2012 - Ben Sweeney
Sometimes we take in every word we read; other times the brain is easily distracted. Ben Sweeney from our Charing Cross Road branch looks at what's going on in the brain when we're reading.
I just finished reading One Soldier's War In Chechnya by Arkady Babchenko on the weekend. It's equally mesmerizing and harrowing, and somehow more poignant when being read on the long bus journey to work. There were a couple of times I had to put the book down and take a breather. There were other times that it seemed to me that I was repressing horrors as I read them.
Do you ever get to the end of the page, or worse the chapter, and realise that precisely none of the words you've just read have registered? What's that about?
I was reading half a chapter, only for my awareness to kick in, and half a chapter of Babchenko's charming eloquence to disappear from memory. Frustrating doesn't even begin to cover the number of times it seemed to happen during this book. And I couldn't begin to explain it; it wasn't through lack of interest, I can assure you.
So, I wagged my chin a bit, and chins wagged back, and it seems that everyone has this problem. That's all good. I'm not alone. But, it's no answer either. So what's actually going on? I went out of my way to understand.
The reading process is very mechanical. As words and sentences build up a world and a direction through which to take you, the procedures your eyes and brain go through are almost robotic.
In recording reader's eye movements researchers have been able to determine that the eye moves systematically across every word, alternating between letter recognition and faster scanning periods. It can spend between 100 to 450 milliseconds on letter recognition. The much faster scanning periods, at about 30 ms a section, cover distances of about eight letters. About nine in ten of these faster sections are progressive, with the remaining one in ten jumping back in the text to material that's already been read.
Every adult who can read competently does this, often regardless of whether they comprehend what they are reading or not. This is because what you're actually doing is scanning a word or phrase, instantly recalling associations with the word or phrase, and storing it in your working memory, wherefrom it either seeps into your long-term memory or disappears in a puff of irrelevance. Great stuff. So why did Babchenko's enthralling stories fail to enthrall my long-term memory so many times?
Your working memory is a marvellous thing. It enables information from various regions of the brain to be manipulated at the same time. Observations have shown that the neurons that fire when you think about an object continue firing for a few seconds after you have finished observing the object. This is your working memory continuing to process the information, trying to decide the relevance of information in regards to whatever problem your working memory is trying to sort out.
Reading is a problem. There's so much to analyse: letters have to be translated into phonemes (which have their own relevance), letters have to be translated into words (which a lot of readers have to translate into sequences of phonemes) and instantly connoted, which have to be considered in whatever sequence they've been viewed in, and whether that sequence is a new or recognised string of words. After all of which your working memory then has to decide how it relates to the narrative that preceded it.
This echo of firing neurons that carries on after the words have been read allows the brain to make associations and connections. As the ideas overlap, the brain is able to form new pathways between neural networks, and the sentence you have read is moved into your brain's long-term storage. But, if your working memory is unable to make these ideas overlap, then you don't have much chance of remembering what you read.
So, while I was reading on the bus, my working memory was busy dealing with some other problem, and the act of reading is so mechanical that I didn't even realise that none of the words were settling in. So there it is, we do learn something new everyday - just sometimes not what we intended to.