Where is the amygdala?

• • Researchers have explored the brain to find differences in structure and function that could be linked to ASD
  • The amygdala stands out as it plays a key role in controlling behaviours affected by ASD
• Structure + functions of the amygdala

  • A cluster of 13 nuclei in the medial temporal lobe of the brain
  • There are two amygdalae - one in each hemisphere of the brain
  • Strongly linked to regions like hypothalamus, prefrontal cortex + hippocampus
  • Amygdala functioning strongly influences the entire brains activity + impacts behaviours related to motivation, emotions + social interactions
• Amygdala developments in ASD

  • In children with ASD, the amygdala develops differently
  • At age 2, children with ASD experience larger than usual increase in amygdala volume, about 6 to 9% more than atypical children (Nordahl et al 2012)
  • By the time they are adults amygdala volume is same as others without ASD
  • ASD children - growth happens earlier which may lead to irregularities in how amygdala's neural organisation works
• Amygdala dysfunction theory of ASD

  • Crucial part of what Brothers (1990) calls the 'socials brain' in humans, as it heavily influences our social behaviour
  • Baron-Cohen et al (2000) suggested that as the amygdala has strong connections with frontal cortex, which is responsible for decision-making, problem-solving + understanding social cues, it's abnormal development during childhood could be a major factor in the main social + behavioural difficulties observed in ASD
  • These challenges affect how people with ASD interact with others + process social information
• Case of SM

  • Adolphs et al (1998) studied on extraordinary individual known as patient SM to scientists + the 'woman who knows no fear' to the media
  • She has Urbach-Wiethe disease, a rare genetic condition causing hardening of specific brain structures including both amygdalas
  • Despite this condition SM's IQ, memory + cognitive functions are normal
  • She understands + identifies positive emotions like happiness but struggles with fear