Vilayanur Ramachandran

Review: Vilayanur Ramachandran: ‘The Emerging Mind’ (BBC Reith Lectures 2003)

Originating as it does from the lectures, the body of text is very concise and accessible. The lectures are supplemented by many equally entertaining pages of notes of varying degrees of digression. They look particularly at specific neurological pathologies (e.g. the usual suspects like synaesthesia, blindsight plus more obscure ones like Capgras, anosognosia) to tease out clues as to what is going on inside normal brains. It is thus more about the workings of the brain and less about consciousness (whether arising via `emergence’ or any other means). Particularly interesting are his speculations on art as virtual reality simulation and on the evolution of language from synaesthesia. See BBC for lecture transcripts and audio. Particular points originating from the lectures will be posted around this blog.

 

Glossary

A list of psychological/neurological conditions (a growing list – originating but not exclusively from ‘The Emerging Mind’) with (often highly conjectural) association to locations within the brain:

  • Prosopagnosia (p. 7) Face blindness. Damage to fusiform gyrus (temporal, both sides).
  • Capgras syndrome (p. 7) Recognition but no emotion: ‘you look like my mother but you are not my mother’. Link from visual centres to amygdala
  • Synaesthesia (pp. 20, 70-94) cross-wiring between number and colour areas in fusiform gyrus. Distinction between number symbol (e.g. ‘6’ rather than ‘VI’) and concept of number (abstract ordinality, December is yellow).
  • abstract idea of numbers: guess angular gyrus (p. 80)
  • Pain asymbolia (p. 23) No pain (respond instead with laughter). Link from cortex (temporal?) to limbic system and/or anterior cingulate.
  • Blindsight (p. 32) ‘I can’t see it even though I can still point to it’ Damage to visual cortex but not to superion colliculus.
  • ‘Neglect’ (p. 37) Opposie of blindsight. No awareness of left side of the world, unless someone directs attention to it. Right parietal lobe.
  • Anasognosia (p. 41-43) ‘Denial’. Paralysed left side by stroke damage but they deny it. Left hemisphere’s coping mechanism is to smooth over discrepancies. Right parietal.
  • Autism (p. 125) Deficient ‘theory of others’ minds’. Deficient mirror neurons.
  • hysterical paralysis (p. 100) Trying to move but nothing happens. Anterior cingulate and orbito-frontal cortex (linked to limbic centres) vetoing motor cortex.
  • Cotard’s syndrome (p. 106) ‘I am dead’. Nothing has any emotional significance.
  • Derealization/depersonalization (p. 107). mini-Cotard: feel like a zombie. Coping mechanism – shut down/detach emotions.
  • epilepsy (p. 109) derealization during seizure.
  • schizophrenia (p. 109) cannot distinguish between own internally-generated images and perceptions evoked by real things outside.
  • stimulation of right parietal cortex causes an out-of-body experience (p. 114)
  • akinetic mutism (p. 119) Awake but no desire to talk/think/choose/act. Anterior cingulate.
  • Wernicke’s aphasia (p. 174) No comprehension of language.
  • Broca’s aphasia (p. 174) Difficulty with grammatical function concepts e.g. if/then.
  • Anton’s syndrome (p. 128) Blind due to cortical damage but denies it.
  • ideomotor apraxis (p. 129) Unable to conjure up internal image. Responds to ‘comb hair’ by hitting head with hand. Left supramarginal gyrus.
  • patients with frontal lobe damage (p. 130) are unable to reflect on the consequences of their actions. No withholding (no ‘free won’t’).

Page numbers refer to ‘The Emerging Mind’ which has a glossary but no index (search the online Reith Lecture instead?).

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