1. A Cognitive Neuroscience
Perspective

2. - Antonio Damasio: Neuroscientist who created the “somatic marker hypothesis” which has gained
traction recently in the fields of affective and cognitive neuroscience
- He also happens to be an author whose books on neuroscience and cognition have won him
numerous prizes in the literary community.

3. Common examples of decision making in our daily lives include:
- which house to buy
- which stock to invest in
- which food to eat
However, derangements in the decision-making process leads to
some of the more severe psychiatric illnesses such as
schizophrenia, mania, OCD, and drug addiction (to name a few)

4. -- The study’s author, Bechera, worked initially with Antonio
Damasio in creating the somatic marker hypothesis.
-- So if decisions are not completely based off of logic and reason,
what else guides the decision making process?

5. -Damasio hypothesized that the primary dysfunction of patients
with vmPFC damage was an inability to use emotions to aid in
decision making, particularly in three realms:
-(1) Personal
-(2) Financial
-(3)Moral
-- This is the fundamental tenet of the somatic marker hypothesis,
that emotions play a role in guiding decisions, especially in
situations in which the outcome are uncertain.

7. -According to the theory, emotions are constituted by changes in
the body. These bodily states are elicited during the decision-
making process and function to “mark” certain options as
advantageous and other ones as disadvantageous.
-- Further experimentation with amygdala damaged patients elicited
similar results to the vmPFC patients, but differed in one
characteristic way: The amygdala patients had impaired skin
conductance responses (SCR) compared to the vmPFC patients
when performing the Iowa Gambling Task, which indicated the
amygdala subjects had an impairment in registering the emotional
impact of rewards and punishments.

9. - The amygdala elicits emotional/bodily states in response to receiving
rewards and punishments.
- Through a learning process, these states become linked to mental
representations of the specific behaviors that brought them about.
- During decision making, the patient will deliberate these behaviors as
options for the future.
- As each option is brought into their mind, the somatic state that was
triggered by that past behavior is reenacted by the vmPFC.
- There are two ways in which emotional/bodily states are represented in
the brain:
1) Mapping at the cortical levels (such as within the insular cortex) which
give rise to “gut feelings”
2) Mapping of bodily states at the subcortical level, which is non-
conscious (like in the mesolimbic dopamine [DA] system).

11. - The insular cortex has been shown to be involved in engaging in
certain types of decision making.
- - Activity in the insular cortex is higher during high-risk decisions than
it is during low-risk decisions.
- - An fMRI study found that the insular cortex is activated when
subjects evaluate the fairness of offers of money from another
subject.
- - This study found that the level of activity in the insular cortex
predicts the likelihood of rejecting an unfair offer.
- - This suggests the insular cortex plays a role in assessing risk and
guiding behavior based on the anticipation of emotional
consequences.
- - The Somatic-Marker Hypothesis attributes this function to the
mapping of visceral states within the insular cortex, which give rise to
“gut feelings”.

12. - The mesolimbic dopamine (DA) system is hypothesized by the
somatic-marker theory to play a role in the unconscious biasing of
action.
- - Recent research has shown that the activity of single neurons
within the mesolimbic DA system is increased by primary reinforcers
but only when these are delivered in an unpredictable fashion.
- - Researchers have shown that activity within the mesolimbic DA
system signals an error between actual and predicted reward and
that such a signal can bias behavior in the direction of behaviors that
are likely to lead to rewards in the future (consistent with the role of
the mesolimbic DA system in the somatic-marker hypothesis.

13. - Recent research has used fMRI to examine the neural systems that
enable moral decisions. Structures included in this moral circuitry
include the vmPFC.
- - vmPFC activation is greater when the moral decision involves
negative consequences for another person, compared to when it
involves no negative consequences for another person.
- - This suggests that moral decision-making engage emotions,
especially when one has to take into account the well-being of
others.
- - The somatic-marker framework has been applied to understanding
drug addiction as well. Substance abusers show real-life decision-
making impairments that are similar to those of patients with vmPFC
damage.
- - In fact, drug addicts and vmPFC patients perform uniformly on the
Iowa Gambling Task, suggesting that addiction may be partially
caused by dysfunction in the vmPFC.

14. - Research still needs to be conducted to parse the mesolimbic DA
system and the insular cortex, and how they influence both conscious
gut feelings and non-conscious biasing of behavior.
- - Further research is being conducted on the role of the mesolimbic DA
system in decision making (see Robbins, 2000).
- - Studies have shown how drug therapies can be used to treat the
decision-making impairments associated with certain mental illnesses.
Panksepp extensively talks about DA levels, and how excessive DA
levels lead to schizophrenia.
- - The somatic-marker hypothesis provides a basis for understanding
how the capacity to make decisions in the moral, social, and financial
realms, are related to basic motivational and homeostatic processes
shared by all mammals. This theory serves as a launching point for
understanding not only decision making, but also a variety of goal
directed processes in which affect and motivation are integrated with the
planning of complex action.

15. - Panksepp’s SEEKING system is essentially a DA system very similar
to the system Antonio Damasio describes.
- - For Panksepp, the extended lateral hypothalamus (LH) is the
system he describes as reacting to homeostatic imbalances,
although Naqvi and Damasio describe more.
- - Both articles focus primarily on the role of the DA systems:
Panksepp describes the DA pathway as coursing through the
ventrolateral regions of the diencephalon (areas of the brain called
the medial forebrain bundle of the lateral hypothalamus [LH]) which
contain many neurochemically specific tracts. One major set of
pathways, the ascending DA circuits, outlines the sites from which
this psychobehavioral state can be most easily evoked with localized
brain stimulation.

16. - Panksepp describes his own version of Damasio’s somatic marker
hypothesis as: “the transient external cues associated with life
sustaining events may be the ones that gradually develop
conditioned neural routes back to the appetitive system. In other
words, the SEEKING system is initially activated by the unconditional
distal incentive cues of rewards, such as smells and sights;
eventually, through learning, neutral cues can come to arouse and
channel activity in this system through a reinforcement process that
is linked to the inhibition of approach in some presently unknown
manner.”
- - The SEEKING system and the somatic-marker hypothesis share
most of the same neural circuits, including the: mesolimbic DA
system (consisting of many smaller structure), mesocortical from the
ventral tegmental area (VTA), and nucleus accumbens.

17. - However, Panksepp detailed other systems that may play a role
such as: DA antagonists which have no role in blocking ESB rat-
sniffing, which is beyond DA control.
- - This means that other neurotransmitters or chemicals must be
involved, and it is believed that the glutamatergic circuits that provide
regulatory control over neuronal bursting activity within the DA
system may be responsible.
- It has been proven that DA is released from the ventral striatum
(i.e., nucleus accumbens), but comparable DA release is not evident
in the dorsal striatum (caudate nucleus) which receives DA
projections mainly from the more lateral nigrostriatal system from the
A9 DA neurons (neurons and pathway responsible for voluntary
movement).

18. - For Panksepp, the homeostatic detectors were located in the medial
strata of the hypothalamus, whereas Naqvi and Damasio add the
vmPFC as the emotional homeostatic control mechanism.
- - Panksepp calls the homeostatic neurons “interoreceptive neurons”
and claims they are the vital resources in promoting the arousability
of the SEEKING system.
- - Both agree that DA from the VTA are responsive to “incentive
stimuli” and are anticipatory in nature.
- - Naqvi et al. (2006) indirectly describes how Damasio created his
theory based off the earlier research of Olds & Milner (1954), who
recorded action potentials from neurons during anticipatory
situations.

19. ANTONIO DAMASIO JAAK PANKSEPP