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The best ideas in science—or in anything else, for that matter—are often the simplest. And another of their characteristics is that they often apply quite generally, and make sense of lots of different findings. The previous post highlighted the way in which critical hormones fit the diametric model of the mind and provide it with an unexpected biochemical basis that fills an important gap between DNA and behaviour. Now a recent paper on hemispheric interaction and individual differences in metaphor comprehension does much the same where neural networks are concerned (authors' diagram above). The study argues the case for a continuum of different mental states
that constrains creative language including metaphor processing. This semantic continuum ranges from a mental lexicon state with extremely low connectivity (resulting in more ordered, rigid organization) to a mental lexicon state with extremely high connectivity (resulting in more random, chaotic organization). In between lies a family of lexicon network states with varying connectivity structure…
These researchers also note the well-established finding that autistics symptomatically have difficulties with ambiguity, metaphor, and irony and that their cognitive style tends to be literal, rule-based, and what I would call mechanistic. As such, they also point out that autistics are therefore on the left, rigid side of the continuum above.
The authors extend their model to include, not only networking as illustrated at the top, but differences between the right hemisphere (RH) of the brain and the left (LH). They argue that on one extreme, persons with autism “exhibit rigidity of thought and have difficulties in processing novel conceptual combinations (novel metaphors) accompanied with reduced RH involvement (…); on the other extreme, persons with schizophrenia exhibiting loose associations, seem to have a different pattern of hemispheric involvement, including increased RH involvement.” In general,
This difference implies different hemispheric mechanisms for metaphorical and literal language. When people comprehend literal language, the LH is strongly involved because the meaning is dominant, focal, and contextually relevant. However when people process metaphorical language, specifically novel metaphors; the RH plays a more important role because the figurative meaning of metaphors requires activations of loosely related concepts in a broader semantic field.
The authors add that “At the micro-anatomical level, LH neurons have smaller input fields than RH neurons in language related brain areas. This difference in input fields may be related to more specific, fine, neural processing in the LH compared to less specific, coarser processing in the RH (…).”
Seeing autism and psychosis such as schizophrenia at the opposite ends of a continuum is the distinctive and most original feature of the diametric model of mental illness which proposes that the autism/psychosis spectrum is in fact one of mentalism (aka theory of mind/people/social skills: the things people do well but computers find very hard to do). Autistic spectrum disorders are symptomatically hypo-mentalistic (meaning deficient in mentalism) as opposed to psychotic spectrum disorders, which are symptomatically hyper-mentalistic (meaning that they exhibit pathologically sensitive mentalism). For example, while autistics tend to be insensitive to others' direction of gaze, paranoid psychotics can be morbidly over-aware of it in the form of delusions of being watched or spied on.
And more to the point where metaphoric language is concerned, while autistics typically take such expressions too literally, manic depressive tendencies have been found to be highly correlated with poetic talent, as I pointed out in a recent post. Manic-depression/ bipolar disorder features exaggerated swings of mood that normally inform a person about their own state of mind (as in "I'm not in the mood"). So it is perhaps not surprising that this particular form of intra-psychic hyper-mentalism is found in so many creative artists who are gifted with being able to express their feelings. And of course, where the medium of expression is words, metaphoric complexity—bordering on chaos in some writers—is to be expected.
According to this dualistic model of cognition, mentalistic cognition varies inversely with mechanistic cognition (understood as machine-like, rule-following cognition: all the things that computers are good at). Mentalistic cognition tends to be contextual, holistic, top-down, centrally coherent and globally connected. Mechanistic thinking, on the other hand, is non-contextual, reductionistic, bottom-up, and non-centrally coherent, with enhanced local but reduced global connectivity. Indeed, according to diametric model of savantism diagrammed below, the surprising implication is that there must be psychotic savants with equal and opposite cognitive configurations to the well-known autistic savants, as I suggested in an earlier post and exemplified in one particularly striking case in a later one.
Another of the implications of the diametric model of the mind is that normality must correspond to a central, balanced condition: enough mentalism to understand other people’s behavior but not so much as to make you paranoid or so little as to make you autistic. So perhaps it is not surprising to find these authors making much the same point: “Thus, emotional well-being is considered a balance of systems that integrate with each other and mental illness can be defined as a shift from a state of integration either to a rigid extreme or to a chaotic extreme.”
Imitation may be the sincerest form of flattery, but an even more sincere form (in science at least) is to find researchers unaware of a new paradigm nevertheless independently rediscovering it in their own investigations. This is exactly what the authors of this paper have done in terms of the diametric model. And if the history of science is anything to go by, it cannot be long before such disconnected and disorganized discoveries are brought together under the over-arching paradigm of the imprinted brain theory, of which the diametric model is a fundamental part.
(With thanks to Bernard Crespi for bringing this paper to my attention.)
Previous posts on related issues:
Brain Imaging Reveals the Diametric Mind
Startling Autistic Findings Confirm Diametric Predictions
Rethinking Autism and Schizotypy: New Findings
