MOTIVATION/EMOTION%20and%20the%20FRONTAL%20LOBES

1
MOTIVATION/EMOTION and the FRONTAL LOBES
left frontal lobe may be most involved in
processing positive emotions right 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
2
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
3
The Amygdala also projects to the Anterior
Cingulate cortex (ACC) of the frontal
lobes(sometimes referred to as the limbic lobe
)
4
The frontal lobes, esp.the medial prefrontal
cortex (mPFC.. further specificity considered in
later slides) also project to amygdala
5
Frontal lobes and the Amygdala

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

6
1. Cortex Dampens Subcortical Affect..SHAM RAGE

• sham rageoccurs 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
  by
• mild tactile or other non-noxious stimuli.

7
Evidence that the frontal lobes Regulate
Subcortical Affective impulses

• Phineas Gage-
• Emotional lability emotional outbursts
• irrationality
• (Deficits in emotional Impusle control)

8
Prefrontal lobotomy
The effects of this procedure varied considerably
9
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 ME influences of
  PFC)
• Apathy, indifference, loss of initiative, loss of
  libido (see ventromedial ACC)

10
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.

11
The Anterior Cingulate Cortex may be critical in
frontal generation of emotion
12
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

13
VON ECONOMO NEURONS and the ACC
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.
14
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.

15
Orbito-frontal cortex and Frontal Poles
16
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-
subjects choices were categorized in terms of
their anticipated and actual emotional impact.
Normal subjects reported emotional responses
consistent with counterfactual thinkingthey
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?
17
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.