Amygdala Flashcards
Classical Fear Conditioning Experiments and lesions
If amygdala removed, rat no longer freezes when any stimuli is presented.
Fear conditioning in humans
Colours (CS) and electric shock (US). Laber et al (1998). Amygdala activated (plus all usual conditioning responses)
John Le Doux’s 2 systems of memory
1996
sensory input - thalamus - (neocortex) - amygdala - emotion. Thalamic route: (thalamic cortical route). Quick: slow.
Emotional memory system - amygdala - responsible for unconscious fear conditioning and appraisal(!) of emotional situations.
Conscious declarative memory - addition of hippocampus and neocortex to the route- memories that are appropriate for the situation are retrieved.
Good guy, bad guy experiment
Tranel and Damasio (1993): brain lesioned patient with complete lesion of left and right amygdala; unable to learn new episodes or faces - emotional memory still functional - amygdala is not necessary for emotional learning.
(Le Doux’s model)
Activation in the amygdala and positive emotions
- drug craving - Childress et al (1999) - pictures of cocaine during rehabilitation.
- sexual arousal - Beauregard et al (2001) - pornography in laboratory.
Non emotional functions of the amygdala
Schaefer et al (2006): classical cognitive task performance was predicted by the activation in the amygdala.
It is possible that the task is seen as a challenge and therefore participant brings in emotion, and am. adds more metabolic resources to the brain systems.
Hypothesis (tentative): am. plays role in preparation of organism when it is facing challenging, goal-relevant situations (both physical and mental). Amydala plays a modulation role, as is linked to a series of brain systems.
Meta Analysis showing each emotion activates more than 1 brain structure and that the same brain structures can be activated for multiple emotions
Phan et al (2002)
