The Neurobiology of Love, Lust, Anger, and Disgust

Displays subcortical activity in the VTA, caudate nucleus, and putamen.

Functions on dopaminergic-rich pathways, giving a similar brain activation as cocaine. Rewarding, positive and motivating.

In response to seeing someone you love, your VTA uses chemical messengers such as dopamine, serotonin, and oxytocin to send signals to the nucleus accumbens. The amygdala is deactivated, as well as the prefrontal cortex.

Companionate Love:

Less intense, feelings of calm, social comfort, and security. Animal studies have shown it to be associated with oxytocin and vasopressin in the nucleus accumbens and ventral pallidum.

Unconditional Love:

Shown pictures of someone with an intellectual disability revealed significant brain activity in the reward and dopaminergic system involved with reward, emotion, and social cognition (Insula, globus pallidus, caudate, VTA, and PGA).

Maternal Love:

Activity in the insula and ant. cingulate cortex. Also, activation in dopaminergic-rich areas.

A specific activation of PAG was observed in maternal (not passionate) love only. This may be because it contains a high density of vasopressin receptors, which are involved in maternal bonding.

Lust:

Dopamine, serotonin, and oxytocin all rush to the nucleus accumbens to initiate sexual wanting. Serotonin turns off sexual wanting, serotonin levels decrease after ejaculation. Sexual arousal activates the reward system: Ventral striatum, Nucleus accumbens, amygdala -> ant. cingulate cortex which initiates autonomic output -> orbitofrontal cortex - responds to the level of perceived arousal and genital swelling.

Anger/Disgust:

Feeling injured or offended with a desire to hurt or threaten the person who offended you. Can be a response to an event or taken out on other people when out of homeostasis.

Anger = violation of autonomy, disgust = violation of purity/divinity, contempt = violation of community standards.

Self-reporting anger: multidimensional anger inventory (includes frequency, duration, magnitude, mode of expression, hostile outlook, and range of anger-eliciting situations.) STAXI (assesses state anger, trait anger, and anger expression and measures how these components contribute to medical conditions.) Constructive anger-behavior verbal style scale (can predict blood pressure) Physiological changes to anger: angry faces, bigger body, deeper voice, eyes widen, lips tighten. Brain = Amygdala and lower levels of prefrontal (same in aggression inhibits)

Aggression:

If a goal is being blocked, people often become frustrated. If we're feeling very angry at the source of that frustration, we may become aggressive. Hostile = violent behaviors, Fear-induced: accompanied by fear and usually when escape is not possible; associated with previous unpleasant experiences. Maternal: Protection of young, a variant of dominant aggression. Intermale: fighting between males, includes elements of competitive, territorial, and sexual aggression. Territorial: behavior directed toward the defense of an area by an individual, the trait is developed in guard dogs that protect property from human intruders.

(Limbic system -> hypothalamus -> brainstem = motor movements)

Rage:

Medial amygdala -> medial hypothalamus -> PAG (leads to aggression)

PAG: helps us to know the next move, Insula: how are you doing internally

Low serotonin = increases aggression, high NE = high aggression, MAO-A- high = high aggression, substance P = high, testosterone leads to aggression.

Disgust:

Insula, hippocampus, ant and post cingulate, Thalamus, primary visual cortex. Lay: combination of disgust and fear, scientific: offense taken to a noxious object