Proustian neuroscience

Paul Raven @ 29-03-2011

In defiance of the title, I’ll keep this brief. (Yeah, I know, I know; some days I even crack myself up.)

A bit of advice I’ve heard a lot with relation to creative writing – moreso with poetry than fiction, but far from exclusively so – is the deployment of “the telling detail”to create versimilitude. You know the way a writer drops one or two close detailed observations into a scene, and they somehow make it all the more real, easy to visualise? (Like the Mastercard sticker of the shard of glass that pins someone to the back wall of a shop, f’rinstance, which I read in a story a few days back and just can’t get out of my head.)

Well, it turns out that may be tapping into a way that our brains store interrelated information. Like the way sometimes you forget a major facet of some event you experienced – say, the important speech given by someone at a conference – but you can remember some irrelevant little detail, like the way their blouse clashed with their Powerpoint slides? There’s a neuroscientific mechanism for that. (Maybe.) [via BigThink]

In response to external stimuli, dendritic spines in the cerebral cortex undergo structural remodeling, getting larger in response to repeated activity within the brain. This remodeling is thought to underlie learning and memory.

The MIT researchers found that a memory of a seemingly irrelevant detail — the kind of detail that would normally be relegated to a short-term memory — may accompany a long-term memory if two synapses on a single dendritic arbor are stimulated within an hour and a half of each other.

“A synapse that received a weak stimulation, the kind that would normally accompany a short-term memory, will express a correlate of a long-term memory if two synapses on a single dendritic branch were involved in a similar time frame,” Govindarajan said.

This occurs because the weakly stimulated synapse can steal or hitchhike on a set of proteins synthesised at or near the strongly stimulated synapse. These proteins are necessary for the enlargement of a dendritic spine that allows the establishment of a long-term memory.

“Not all irrelevant information is recalled, because some of it did not stimulate the synapses of the dendritic branch that happens to contain the strongly stimulated synapse,” Israely said.