Professor Allan Snyder is one of the most creative and cool scientists I know. Recognized for discoveries in the fields of biology, communications, optical physics and neuroscience, he received the world's "foremost prize in communication and information technology", the Marconi International Prize, in 2001 - a prize previously bestowed on the inventor of the internet and the founders of google. His discoveries in brain science are hailed in the journal Nature as "breaking a 19th century mindset", and are declared "a breakthrough that could lead to a revolution in the way we understand the functioning of the human brain" by the New York Times. Snyder is currently the Director of the Centre for the Mind at the University of Sydney.
Snyder believes a 'thinking cap' might one day be possible, which would enable us to remove our ordinary filters of perception, and thereby improve memory, reduce prejudice, and make us more creative. Here I have a conversation with the award winning scientist who is inventing ways to access nonconscious savant-like skills, to enhance creative thinking, and to unravel the ingredients of extraordinary success.
S. You have argued that savant skills are latent in all of us. Could you please elaborate why you think this is true?
A. My hypothesis is that savants have privileged access to lower level, less-processed information, before it is packaged into holistic concepts and meaningful labels. Due to a failure in top-down inhibition, they can tap into information that exists in all of our brains, but is normally beyond conscious awareness.
Several lines of evidence point to this interpretation. Savant skills appear to be universal - they don't seem to vary according to what's valued in a particular society. Across different cultures, savant skills are restricted to the same domains: art, music, calendar calculating, arithmetic, and mechanical/spatial skills. The skills can emerge without training, and they're not qualitatively improved by practice. In fact, savants generally don't have insight into how they perform their skill.
Compellingly, this applies (for example) even for savant skills that emerge later in life, as a result of damage to the left temporal lobes, through frontotemporal dementia, stroke, or physical injury. Patients can suddenly and spontaneously demonstrate skills for which they previously had no interest, ability or talent. This suggests that the basis for these skills was there all along, albeit beyond conscious awareness.
S. Why do you think rTMS improves a person's savant-like abilities?
A. We use low-frequency repetitive transcranial magnetic stimulation (rTMS) to inhibit the anterior temporal lobe, a region important for semantic processing, conceptual knowledge, labels and categories. In normal people, conceptual regions dominate over those that process literal detail. In effect, we attempt to inhibit (or reverse) this natural state of inhibition, to shift the balance in favour of greater access to literal detail.
Our approach is consistent with evidence that savant syndrome is often associated with left brain dysfunction or inhibition, together with right brain compensation, leading to a predilection for literal, non-symbolic skills. Or, as Oliver Sacks put it, normally, abstract and verbal powers are associated with the left or dominant cerebral hemisphere and perceptual skills with the right. We attempt to temporarily induce disinhibition of the right hemisphere in normal people.
Obscuring the meaning of something allows us to become more aware of the details that comprise it. By way of example, Betty Edwards, in her book Drawing on the Right Side of the Brain, developed techniques for improving drawing skills, including turning the object to be drawn upside down - the object's meaning is removed, improving attention to its details.
S. How successful have you been in inducing savant-like skills in normal individuals? If savant-like skills are latent in all of us, why don't your methods work on all of your participants? Could it be that there are individual differences in these abilities, regardless of whether they are initially hidden or not?
A. Our success in inducing savant-like skills in normal individuals using low-frequency rTMS has been moderate. Not everyone responds. There's a number of possibilities for why not all individuals show the same marked improvement. It's possible that individual differences in how detail-orientated people are to start with account for some of the variability. Some people may be closer to the precipice than others.
We're confident that savant skills latent in us all, but unfortunately there are technical issues and limitations - stimulation is less effective in people with thick hair or skulls :), and its effectiveness depends on the orientation of the brain's sulci (or grooves), as well as the amount of myelination (neural conductivity). And, TMS has relatively poor spatial resolution, making it hard to target a specific location or neural network. So, for all these reasons, it's likely that we stimulate the 'sweet spot' (or network) in some people more successfully than in others.
But, despite these complications, we believe that reliably getting any 'pig to fly' (so to speak) provides proof of principle, so we're encouraged. And, it's worth noting that our recent work using transcranial direct current stimulation (tDCS) is showing a more powerful effect.
S. Is it possible that the act of having the participants read the same sentence both times increases the chance that they will pick up the repeating word despite the fact they've received magnetic stimulation?
A. Yes indeed - that's why we compare the effects of stimulation with performance under sham stimulation (placebo). But, a famous neurologist of my acquaintance (guess who?) was once driven to distraction by my insistence that he repeatedly read one of the sentences - he failed to spot the duplicated word, even after many, many readings. It just goes to show how powerful our conceptual mind is. We tend to see what we know!
S. Are there any trade-offs to using your methods? Are there any abilities temporarily impaired when you stimulate the left anterior temporal lobe (LATL)? What potential negative consequences do you think could come as a result of turning on an area of the brain at the expense of disengaging another?
A. We haven't observed any trade-offs. But, we don't give our participants an exhaustive battery of tests - we can't, since the effect of brain stimulation wears off too quickly.
In theory, we'd predict that a person would become less conceptual, which might be reflected in a variety of ways. Consistent with this, Gorana Pobric and Matthew Lambon Ralph at the University of Manchester found that rTMS inhibition of the left anterior temporal lobe (LATL) produced difficulty in distinguishing concepts, particularly specific-level ones (e.g. golden retriever, more so than dog).
S. Why are savant skills suppressed in normal individuals?
Professor Allan Snyder is one of the most creative and cool scientists I know. Recognized for discoveries in the fields of biology, communications, optical physics and neuroscience, he received the world's "foremost prize in communication and information technology", the Marconi International Prize, in 2001 - a prize previously bestowed on the inventor of the internet and the founders of google. His discoveries in brain science are hailed in the journal Nature as "breaking a 19th century mindset", and are declared "a breakthrough that could lead to a revolution in the way we understand the functioning of the human brain" by the New York Times. Snyder is currently the Director of the Centre for the Mind at the University of Sydney.
A. We use low-frequency repetitive transcranial magnetic stimulation (rTMS) to inhibit the anterior temporal lobe, a region important for semantic processing, conceptual knowledge, labels and categories. In normal people, conceptual regions dominate over those that process literal detail. In effect, we attempt to inhibit (or reverse) this natural state of inhibition, to shift the balance in favour of greater access to literal detail.
