Double dissociation of conditioning and declarative knowledge relative to the amygdala and hippocampus in humans

A patient with selective bilateral damage to the amygdala did not acquire conditioned autonomic responses to visual or auditory stimuli but did acquire the declarative facts about which visual or auditory stimuli were paired with the unconditioned stimulus. By contrast, a patient with selective bilateral damage to the hippocamous failed to acquire the facts but did acquire the conditioning. Finally, a patient with bilaterirdamage to both amygdala and hippocampal formation acquired neither the conditioning nor the facts. These findings demonstrate a double dissociation of conditioning and declarative knowledge relative to the human amygdala and hippocampus.
Studies in animals have established that the amygdala is critical for emotional conditioning (1), whereas several human and nonhuman primate studies have established that the hippocampus and surrounding regions are [...]