Excepts from ″Explaining and inducing savant skills: privileged access to lower level, less-processed information″ by Allan Snyder, available here
There are now several accounts of artificially induced savant-like skills, in drawing, proofreading, numerosity and false memory reduction, all by inhibiting the LATL with repetitive transcranial magnetic stimulation (rTMS; Snyder et al. 2003, 2006; Young et al. 2004; Gallate et al. 2009).
(i) Why does becoming more literal enhance numerosity?
We argue that the estimation of number by normal people is performed on information after it has been processed into meaningful patterns. The meaning we unconsciously assign to these patterns interferes with our accuracy of estimation, whereas savants, by virtue of being literal, have less interference.
This insight has an important generalization. The healthy brain makes hypotheses in order to extract meaning from the sensory input, hypotheses derived from prior experience (Gregory 1970, 2004; Snyder & Barlow 1988; Snyder et al. 2004). So judgements in general are likely to be performed on this hypothesized content, not on the actual raw sensory input. This suggests the possibility of artificially reducing certain types of false memories and prejudice by making a person more literal, as well as enhancing creativity (Snyder et al. 2004).
The majority of savants are autistic. Why not all? Autistic spectrum disorders encompass a hugely diverse population. However, it may well be that autistic savants represent autism in its purest form, uncontaminated by learned algorithms and other disorders that are frequently associated with autism. In other words, autistic savants typify an idealized, pure autism, most closely identified with Kanner’s (1943) infantile autism—a mind in a protracted state of infancy (Snyder et al. 2004), a preconceptual mind that thinks in detail, rather than through concepts. This oversimplifying caricature goes some way to explain why all autistic people are not savants.
But, creativity would seem to require that we, at least momentarily, free ourselves of previous interpretations. Such literalness is a consequence of privileged access and thus gives insights into the so-called autistic genius (Snyder 2004) as well as hints to artificially enhance creativity (Snyder et al. 2004).
The classical portrait of autism is that of rigid insistence on sameness, rote memory and significant learning disabilities. Even autistic savants are the antithesis of creative, being largely imitative: ‘there are no savant geniuses about… Their mental limitations disallow and preclude an awareness of innovative developments’. (Hermelin 2001, p. 177).
The fact that genius might fall within the autistic spectrum challenges our deepest notions of creativity. Are there radically different routes to creativity: normal and autistic? The autistic mind builds from the parts to the whole—a strategy ideally suited to working within a closed system of specified rules. By contrast, the ‘healthy’ mind appears to make unexpected connections between seemingly disparate systems, inventing entire new systems rather than finding novelty within a previously prescribed space
Perceptual experience is influenced both by incoming
sensory information and prior knowledge about the
world, a concept recently formalised within Bayesian
decision theory. We propose that Bayesian models can
be applied to autism – a neurodevelopmental condition
with atypicalities in sensation and perception – to
pinpoint fundamental differences in perceptual mechanisms.
We suggest specifically that attenuated Bayesian
priors – ‘hypo-priors’ – may be responsible for the
unique perceptual experience of autistic people, leading
to a tendency to perceive the world more accurately
rather than modulated by prior experience. In this account,
we consider how hypo-priors might explain key
features of autism – the broad range of sensory and
other non-social atypicalities – in addition to the
phenomenological differences in autistic perception.
Excepts from ″Explaining and inducing savant skills: privileged access to lower level, less-processed information″ by Allan Snyder, available here
Closely related: When the world becomes ‘too real’: a Bayesian explanation of autistic perception