NAB-Emotion

Emotions are states elicited by rewarding or aversive stimuli (S+ or S-) and their omission(-) or termination(!).

These states comprise thoughts and physiological/behavioural responses to emotional (i.e. rewarding or aversive) stimuli.

The physiological/behavioural responses to emotional stimuli can unambiguously be measured in human and non-human animals.

These physiological/behavioural responses to aversive and positive stimuli have fundamental survival value and, therefore, have been relatively preserved throughout evolution and are very often very similar in different animals including humans.

With the similarities between species, we can study emotions in animals and generalise it.

E.g. using rats as a model system:

>Advantages-easy to breed and keep, well-established behavioural tests, brain large enough to apply selective manipulations to distinct brain structures and brain anatomy very well characterised.

>Disadvantage-difficulty in genetic manipulations->alternative=mouse

Hippocampus, amygdala & hypothalamus:

-Papez theory of emotion (1937)

-Kluver and Bucy's description of temporal lobe lesion effects in monkeys (1939)

-Maclean's limbic system theory (1949)

Prefrontal cortex:

-Case of Phineas Gage described by Harlow (1868)

-Nauta (1971): Frontal lobes and interoception

Meso-corticolimbic dopamine system:

-Olds and Milner (1954): Brain-stimulation induced reward

-Wise et al. (1978): Neuroleptic-induced anhedonia