Machado 2008

Question 1

Machado 2008, method

Answer 1

Bilateral lesions to amygdala, hippocampus, or orbitofrontal cortex in rhesus macaques.
Human Intruder Paradigm
Examined behavioral reactivity (e.g. Tooth grinding, tension, cage aggression, etc.)
Also evaluated impact of each lesion on circulating cortisol and testosterone levels

Question 2

Machado 2008 results hippocampus

Answer 2

Hippocampal lesions:
decreased tooth grinding
increased tension

Question 3

Machado 2008 results Amygdala

Answer 3

Amygdala lesions:
reduced freq/duration of defensive freezing,
increased tension-related behavior
blunted cortisol reactivity during SOCIAL ISOLATION

Question 4

Machado 2008 results OFC

Answer 4

OFC lesions:
reduced intruder-directed defensive behaviors (cage aggression, tooth grinding)
Decreased freezing
Blunted cortisol reactivity during social isolation