Functions of limbic system are:
1. Role in emotion:
Different emotions produce different sets of behaviors. Emotional expressions during rage, sex drive, affection and pleasure are all different. Amygdala stimulation is known to induce fear and anxiety behavior in human beings.
2. Sexual behaviour:
Sexual activity has different components namely sex drive (urge to copulate), sex behavior and act of copulation. Sex behavior is due to both neural and endocrine components.
3. Reward and punishment:
Lateral hypothalamus, septum, median forebrain bundle, etc., are reward areas. If an electrode placed in any one of these regions in an animal and if animal is placed in a specially designed box namely Skinner’s box, the animal repetitively presses the pedal to have sensation of pleasure.
This is because stimulation of reward area brings about a sensation of pleasure. On the other hand, if electrode is placed in punishment area, stimulation of this area leads to punishment.
4. Motivation:
It appears that conditions which result in stimulation of reward areas produce motivation to do a job.
Kluver-Bucy Syndrome:
Bilateral temporal lobotomy leads to:
a. Placidity
b. Hypersexuality
c. Hyperorality
d. Viusal agnosia
e. Omniphagia
Placidity:
The animal loses sense of fear and start interacting with any creature without usual fear or aggressive reaction.
Hypersexuality:
Sexual drive is increased and tries to copulate with an animal of same sex or opposite sex and at times even with inanimate objects.
Hyperorality:
Tries to put anything and everything into mouth and thereby tries to examine anything and everything.
Visual agnosia:
Even though visual pathway is very much functional, animal may dash against an object since analysis of visual impulses has been totally lost.
Omniphagia:
Eats anything and everything.