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Science Blog Questions
Last updated on February 06, 2011 at 02:10 PM
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Scientific Question and Answer Blog


This blog will answer scientific questions posed by readers. With the answer, a brief history or introduction of the scientific area will be discussed. Also, the answer will provide specific evidence, such as observations and experiments that support the answer. As a summary, it will also provide the possible implications of the scientific findings.


3. Question. Can the brain become overloaded prior to and affect the decision-making process?


Introduction. When I returned back to the United States after my Peace Corps stint, I met up with a close high school friend who was just returning from Vietnam. We met in San Francisco to reprogram ourselves to life in the United States. After our long absence abroad within poorer nations, we had become quite alien to the abundance in the United States. For example, while we roamed through a grocery store, we became stunned in silence while looking down the long aisle that literally offered hundreds of different cereals. As if a deer in the headlights, our brains were paralyzed into indecision and we couldn’t choose. Due to our lack of response, I began to think that the decision-making process could be over-loaded. Recent studies on the brain’;s decision-making process have indicated that I may have been correct.


History. The neuroanatomy of cultural or social decision-making process was initially discovered using observations of patients that had lost this skill or ability during localized damage within their brains. One original case that revealed the area of the brain involved in decision-making occurred in Vermont in 1848. Twenty-five year old railroad worker Phineas Gage was laying track when an accidental explosion blew a thin iron bar through the front of his head. Prior to this explosion, Gage was acknowledged by his workers as a, “;most efficient and capable”; railroad worker and manager. The explosion threw the rod through his cheek and the front part of his skull transporting a small piece of brain with it. He made an excellent physical recovery, but displayed a remarkable change in behavior. He was later “;fitful, irreverent and self-indulgent.”; He was incapable of planning and making day-to-day decisions and he ended up quite slovenly. His braincase was saved and was recently analyzed to assess the specific area that was lost. Through MRI digital analysis, this area was determined to be the ventromedial prefrontal cortex.


Evidence. Quite recently a group of MIT economists conducted an “auction with their business-school graduate students.” The same decision-making experiment was also done with executives and managers and very similar results and conclusions were obtained. Researchers auctioned a number of eclectic items to bid upon, including a fancy bottle of French wine, a cordless keyboard and a box of chocolate truffles. Prior to the auction, the subjects, who were to bid, were asked to write down the last two digits of their social security numbers (SS#). Afterwards they were asked if they’d pay that numerical value for each of the items to be auctioned. For example, if their last two SS# digits were 66, then they’;d have to decide if they’;d pay $66. Lastly, the students were asked to write down the maximum amount they were willing to pay for each of the items.


Students with the highest-ending final two SS numbers (80-99) made an average bid of 56 dollars, whereas students with the lowest-ending final two numbers (1-20) made an average bid of 16 dollars. Thus, on average, those with higher numbers made bids 300% higher than those with low final SS# digits. Students knew that this shouldn’;t influence their decision, but there was definitely an anchoring effect of their SS#’;s upon their bidding decisions.


Implications. A meaningless anchor did have an effect upon the business students’; subsequent bidding decisions. This anchoring effect tells us that prefrontal cortex of the brain is unable to dismiss irrelevant information when making decisions. With all the gossip, nonsense and mental fog that pose as information over the internet, T.V. and other media, it is not surprising that that this media may influence our decisions by anchoring or other subtle ways that we are not aware of.


References.


1. Ariely, D., Lowenstein, G. and D. Prelec. 2003. Coherent arbitrariness: Stable demand curves within stable preferences. Quarterly Journal of Economics 118: 73-105.


2. Damasio, H., Grabowski, T., Frank, R., Galaburda, A.M. and A.R. Damasio. 1994. The return of Phineas Gage: The skull of a famous patient yields clues about the brain. Science 264: 1102-1105.


1.  We keep hearing that exercise and eating right are good for both our mental and physical health. Is there scientific support for this?


Answer: Yes, recent studies indicate that both good nutrition and regular exercise are necessary for optimum mental and physical health.


History: I call this the Jack LaLanne Effect named after the exercise and nutritional guru from Southern California who advocated this combination during his T.V. exercise programs of the early 50s. During his tenth decade of life, he still does with his promotional advertisements for fruit pulverizers on shopping network.


Evidence: During the late 80s using a new technique (BrdU Immunocytochemistry), Fred Gage (at the University of California, San Diego) demonstrated that mammalian and adult human brain cells can undergo cell division and generate new nerve cells. Thus, new nerve cells can form in adults and this aids in later mental function. This was demonstrated, in particular, for hippocampal brain cells, which is the brain part needed for the formation of new memories. Later during 2005 to 2007, Dr. Gage's student Henriette van Praag demonstrated that both good nutrition and exercise enhance this brain cell division. Her studies strongly demonstrated that exercise facilitates cognition and memory (mental alertness), and ingestion of nutrients such as flavanols, omega-3-fatty acids and folate (folic acid) further facilitate the memory processes by reducing brain cell damage. I call this combination the Jack LaLanne effect, because he advocated exercise and these nutrients long before science demonstrated their real benefits.


2.  Does disturbed sleep promote obesity?


Answer: Yes, people who do not get enough hours of “deep sleep” do tend to gain weight.


History: One would think that the more you sleep, the greater your weight would be, because mammals (and humans) burn more calories during the waking or active hours. But recent studies indicate that humans require a number of solid, undisturbed sleep hours in order to properly regulate their day and night metabolism.


Evidence: There are two known hormones that regulate or control a person’;s appetite. High ghrelin levels will promote increased hunger and appetite. High leptin levels promote a sense of feeling full or satiation. Recent studies published in the May issue of Psychoneuroendocrinology demonstrated a significant elevation in ghrelin levels for known insomniacs (individuals with trouble sleeping). This hormone imbalance leads these insomniacs to have an increased appetite during the day, ultimately leading to weight gain over time.


Implications: It is well known that individuals over the age of fifty as well as first-year college students have more days with disturbed sleep patterns compared to their previous sleep situations. This is due to aging’s effect on sleep patterns and the first year student’;s adjustments to the new college life. These two groups also exhibit increased weight gain despite diet regimes and changes in exercise patterns. This weight gain “may” be primarily due to these changes in sleep patterns. Aside- obesity is a contributing factor in the deeply disturbing sleep pattern called sleep apnea, so once someone becomes excessively overweight; hunger becomes a vicious cycle due to changes in sleep patterns.

gerald.eagleson
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