Attracting Abundance

The Law

Two Doors to Success

Happiness - VIII

The first clue that the neural connections for sustainable happiness might be different from the short term elicitation of positive emotions came from studies with depressed patients. It was investigated whether depressed patients show the typical pattern of activation in response to positive stimuli and the results were compared with a control group on non-depressed patients. (Heller et al, 2009, Proceedings of National Academy of Sciences, 106(52), 22445 - 50). Robust difference in activation in reward-related brain regions were not found between the depressed people and the control group. However when the data was further analyzed for the capacity of brain to sustain activation in the nucleus accumbens over time, robust differences were observed between the depressed people and non-depressed people. The non-depressed group retained activation in the nucleus accumbens while the depressed group did not. The difference became sharper as repeated activations were done. As mentioned earlier the nucleus accumbens is a cluster of neurons (nerve cells) in the ventral striatum that is commonly associated with positive effect and reward. Moreover, when connectivity between the nucleus accumbens and other brain regions was examined, it was connectivity between the nucleus accumbens and the middle frontal gyrus, ( a region that has been associated with regulation and goal-directed behavior) that showed sustained activation among the non-depressed group but dropped off with increased trial in the non-depressed group.

(Note: a gyrus is a ridge on the cerebral cortex. It is generally surrounded by one or more suici (depressions or furrows). Gyri and sulci create the folded appearance of the brain in humans and other mammals).

This study provided the first strong experimental evidence that the ability to maintain positive emotion over time, are associated with sustained activation in the ventral striatum and with sustained connectivity between regions of prefrontal cortex and the ventral striatum. Depressed people differ from non-depressed people on these metrics.

In a recent study involving a large community sample (see http://wwww.midus.side.edu). relation between individual differences in sustained activity in the ventral striatum and psychological well-being was experimentally examined. It was observed that individuals with higher level of psychological wee-being on Ryff Composite Measure of well being.

(Note: Well-being is a dynamic concept that includes subjective, social, and psychological dimensions as well as health-related behaviors. The Ryff Composite Measure of Well-Being is a theoretically grounded instrument that specifically focuses on measuring multiple facets of psychological well-being. These facets include the following:

• self-acceptance
• the establishment of quality ties to other
• a sense of autonomy in thought and action
• the ability to manage complex environments to suit personal needs and values
• the pursuit of meaningful goals and a sense of purpose in life




Dorsolateral Prefrontal Cortex

• continued growth and development as a person)

In addition, similar pattern was also observed in dorsolateral pre-frontal cortex, a region involved in working memory and attention, but also active when a person is regulating his or her emotion.

This activity in these two areas was then correlated with cortisol output, which we know to be a measure of body's response to stress signals. It was seen that the individuals with greater sustained activation in ventral striatum and dorsolateral preforntal cortex had lower levels of cortisol which implies a less intense activation of body's stress response system. These findings indicate that the findings on depressed individuals can be generalized to even healthy individuals which is that sustained activation across time in response to positive incentives in the ventral striatum and dorsolateral prefrontal cortex predicts psychological well being , a form of sustained happiness, that may not directly depend upon external circumstances.

Studies have been done on assessing the duration of positive and negative effects using peripheral physiological measures. (Jackson et al, 2003, Psychlogical Science, 14(6), 612 - 17). Using measures of facial electro-myography (fEMG), facial expression behavior that follows the onset of emotional signal can be used to probe the extent to which positive and negative effects persist beyond the eliciting signal. Short lived responses to positive signal would indicate lower level of well being and should be impacted by stressful life experience. In one study on 116 participants (see http://www.midus.wise.edu) it was observed that individuals exposed to prolonged marital stress exhibited short-lived responses to positive stimuli. And also the individuals with short-lived responses to positive stimuli show lower level of well being compared to those who exhibit prolonged activity to positive stimuli. These finding suggest that some of the key chronic obstacles such as marital stress may undermine well being by specifically diminishing the capacity to sustain positive effects.

In a novel study (Telzer et al, 2014, Proceedings of National Academy of Sciences, 108(27), 15244 - 64) on adolescents over a period of 2 years, brain activity was assessed with fMRI in response to two separate tasks that putatively engaged hedonic and eudaimonic emotions respectively. The study revealed that the ventral striatum activation in response to eudaimonic tasks (a family donation task that involved personal loss in the service of overll family gain) predicted longitudinal decrease in depressive symptoms while response to hedonic reward task did not. Hence the context in which the ventral striatum activation is observed is significant and determines the network with which it associates.

Namaste

Prabir