MOTIVATION/EMOTION and the FRONTAL LOBES

left frontal lobe may be most involved in processing positive emotionsright frontal lobe involved with negative emotions

Remember that the thalamus projects to both the amygdala ….and to sensory cortex areas.. Where it is eventually processed by the frontal lobes

The amygdala also projects to the frontal lobes mainly to the “Prefrontal cortex” …the frontal cortical areas found anterior to the 2nd and primary motor areas

The Amygdala also projects to the Anterior Cingulate cortex (ACC) of the frontal lobes…

(sometimes referred to as the “limbic lobe” )

The frontal lobes, esp.the medial prefrontal cortex (mPFC.. further specificity considered

in later slides) also project to amygdala

Frontal lobes and the Amygdala

• What role does the pathway from the prefrontal cortex to the amygdala play in emotion and motivation??

1. Cortex Dampens Subcortical Affect…..SHAM RAGE

• sham rage—occurs following removal of the cerebral cortex from experimental animals..

• In Cats:– lashing of the tail, vigorous arching of the back, clawing and attempts to– bite, and autonomic responses. It is called sham rage because unlike– genuine rage ( or predatory aggression)

the rage occurs spontaneously or can be triggered bymild tactile or other non-noxious stimuli.

Evidence that the frontal lobes Regulate Subcortical Affective

impulses• Phineas Gage- • Emotional lability

emotional outbursts• irrationality

(Deficits in emotional Impusle control)

Prefrontal lobotomy

The effects of this procedure varied considerably

Perhaps due to differences in procedure- two general syndromes associated with frontal lobotomy (as well as naturally incurred frontal lobe damage)

-Pseudopsychopathy- (indicates loss of regulatory functions)

• Immature impulsive behavior, aggressive outbursts, Inappropriate jocular affect , Poor judgment and insight , coarse language, promiscuity, general loss of social skills, euphoria, Emotional lability, Distractibility (see orbito-frontal cortex)

Pseudodepression – (loss of M&E influences of PFC)

– Apathy, indifference, loss of initiative, loss of libido (see ventromedial ACC)

Other effects of Frontal Lobe Damage relating to affect and motivation

-difficulty formulating common rules and goals. if a rule or goal is given to the patient there is great difficulty in using it

to guide behavior. ..perhaps related to social motivations

• Actions are motivated by immediate gratification of simple impulses… Relates to circumstantiality

• dissociation between the discriminative and affective aspects of pain. When stuck with a pin, such a patient reports that it hurts, but it doesn't bother him.

The Anterior Cingulate Cortex may be critical in frontal generation of emotion

lesion of the ACC

• - patients described as apathetic and

unconcerned when significant events occur, such as making mistakes (Eslinger and Damasio, 1985 ; Rylander, 1947 )…like pseudodepression

When we interact with another person we create a mental model of how that persons thinks and feels. We are likely to have initial, quick intuitions about the person, which are then followed by slower, more reasoned judgments.

Both intuition and deliberation are influenced by emotional value judgments.

Von Economo neurons (VENs) are a recently evolved cell type which may be involved in the fast intuitive assessment of complex situations.

VENs emerge mainly after birth and increase in number until age 4 yrs.

VON ECONOMO NEURONS and the ACC

The Social Function of VENs?

• Social bonding ? – More active when subjects view an image of a loved one compared with that of an

acquaintance

• Certainty – active when subjects make decisions under a high degree of uncertainty.

• Pain?– Active when subjective experience of pain … which is powerfully magnified by uncertainty.

• also active when subjects experience guilt, embarrassment and engage in deception

• ACC also active in humor (Watson and Allman,• trust, empathy, and the discrimination• of the mental states of others

• All of these social emotions are influenced by the degree of uncertainty involved. •

Orbito-frontal cortex and Frontal Poles

Counterfactual processing -The consequence of a decision/behavior can lead to feelings such as: satisfaction, relief, or regret… evaluation of the potential outcomes of alternative decisions.

Testing the role of the orbito-frontal cortex in counterfactual reactions- a simple gambling task was used- subject’s choices were categorized in terms of their anticipated and actual emotional impact.

Normal subjects reported emotional responses consistent with counterfactual thinking;they chose to minimize future regret and learned from their emotional experience. (also associated with increased activity in the orbito-frontal regions)

Patients with orbitofrontal cortical lesions, however, did not report regret or anticipate negative consequences of their choices.

ORIBITO-FRONTAL CORTEX- counterfactualprocessing/ Regret?

Damage to the orbito-frontal cortex? May partially account for the pseudopsychopathic syndrome

• lack of originality and creativity• impairment of attention• difficulty initiating behavior; when they do engage in activity, they

may continue the activity without stopping. • They may only start activity when prompted by others

(“circumstantiality?”).

• “Like pseudopsychopathy”-Emotional disturbance most often results from lesion of the orbital frontal areas.

• superficial emotional expression like laughing, crying etc in situations inappropriate to the emotion. The patient usually has no awareness that their emotional response is incorrect or extreme.