Moral Judgment Mind Control

A man steals candy from a baby. Whether or not the baby cries, most would argue that the man acted immorally. It seems that humans have an innate ability to judge if an act is moral or not, regardless of the act’s outcome or consequences.

How we judge whether actions are moral or not is a subject that some people attribute to human spirituality, while others simply chalk it up to the mysterious inner workings of the human mind. A study recently published in the Proceedings of the National Academy of Sciences by Dr. Liane Young and colleagues from the Massachusetts Institute of Technology may just bring us one step closer to understanding how the brain controls our moral judgments.

When judging the morality of another person’s actions, we usually analyze the person’s intent. For example, if the man who stole candy from the baby did so to protect the baby from a closely swarming bee, his actions might be considered permissible. This conclusion requires our ability to infer the mental state of another person. Dr. Young hypothesized that an area of the brain involved in mental state reasoning, called the right temporoparietal junction (RTPJ), would be required for making moral judgments.

To test this hypothesis, Young’s group disrupted the RTPJ using transcranial magnetic stimulation (TMS), a noninvasive technique that uses focused magnetic fields to disrupt neural activity in a specific area of the brain. Volunteers were then asked to make moral judgments about fictitious scenes.

The experiment included four scenarios. Each scenario consisted of either a neutral act or negative act combined with a neutral outcome or negative outcome. When the volunteers received TMS on a control area of the brain (in other words, the RTPJ was functioning), most of the participants indicated that a negative act was less permissive, whether or not the outcome was neutral or negative. However, when the RTPJ was disrupted, the volunteers indicated that the negative act was more permissible if the outcome was neutral. 

This suggests that with the RTPJ disrupted the volunteers based their judgments on the outcome, rather than the act itself.

In the man and baby scenario, this study implies that a disrupted RTPJ would lead a person to conclude that stealing candy from a baby is permissible as long as the baby doesn’t cry.

The Bottom Line: The right temporoparietal junction of our brains helps correlate intentions and outcomes when making decisions about the permissiveness (morality) of another person’s activities.

So, cultural exposures aside, it’s interesting to think about friends who seem more comfortable with—what some might consider—immoral acts, as long as there isn’t a bad outcome…

Reference: Proc Natl Acad Sci U S A. 2010 Apr 13;107(15):6753-8. doi:10.1073/pnas.0914826107

Yet another amazing feat by the human brain

Every day the human brain commits vast amounts of information to memory. No single man-made machine can match the immense storage capacity contained within the brain’s approximate 100-billion neurons. How our most complex organ sifts through a steady stream of sensory input—deciding what is important versus what is trivial—is an area of intense scientific investigation.

In a study recently published in the journal Plos Genetics, scientists report that memory formation is enhanced by attention-demanding tasks. A group from the University of Washington, led by Dr. Jeffrey Y. Lin, presents a set of experiments that test participants’ memory during image recall.

In each experiment, participants are shown a series of urban and rural scenes and asked to correctly indicate if an image has been presented in the set of pictures. A fifty-percent correct answer rate, or that which could be achieved by simple guessing, would indicate little to no memory is formed. In the first experiment, Lin reports that participants are correct fifty-one percent of the time, indicating a lack of memory formation. However, in a subsequent test, Lin’s team pairs the scenery images with a black or white letter and asks participants to remember which letter is white. Surprisingly, even though the participants are not specifically asked to memorize the scenery in the images, the participants are able to correctly recall the scene with the white letter sixty-seven percent of the time, indicating a statistically significant result.

This finding suggests that the act of performing an attention-demanding task causes the brain to enhance the memory of what surrounds the target of focus (i.e. the urban and rural scenes surrounding the letter). Lin’s team finds a similar result when the scenery images are paired with two auditory tones, with participants correctly remembering the image paired with the target tone almost sixty-five percent of the time.

To verify that memory is enhanced by the focused task, and not by the presentation of a novel stimulus, (in this case a newly colored letter), participants are shown the images with letters again, but are told not to take note of the white letter. In this case, no memory enhancement is observed, suggesting that the attention-demanding task itself enhances memory.

The Bottom Line: The brain can automatically perceive and encode visual stimuli in attention-demanding settings, suggesting that our brains are wired to involuntarily remember more about our environment when we are presented with a situation that requires focused attention.

Reference: Lin JY, Pype AD, Murray SO, Boynton GM. (2010). Enhanced Memory for Scenes Presented at Behaviorally Relevant Points in Time. PLoS Biol. Mar 16;8(3):e1000337

Plos Biology is an open-access journal. This research article can be downloaded at:
http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1000337

Moving cross-country

Sorry for the lack of posts this past week. I'm in the middle of a cross-country move and will write another science blog again shortly! Check back soon!

A fish a day keeps the doctor away

Is it true that there can be too much of a good thing? In the case of inflammation, the answer is certainly YES. Inflammation can be seen as the familiar red puffiness around a healing wound or the unseen swelling of an injured organ. Inflammation is the result of the immune system responding to dangerous pathogens, such as bacteria or parasites. Without it, our bodies would fail to heal wounds and fight off infections. When inflammation goes unchecked, however, serious tissue damage can result. Imagine a scraped knee. A little soap and water can do a lot to prevent infection, while non-stop scrubbing of the wound will eventually do more harm than good. Inflammation is a similar scenario, only at the molecular level. Artherosclerosis, rheumatoid arthritis, fibromyalgia, shoulder tendinitis, inflammatory bowel disease, to name just a few, are all associated with inflammation.

The human immune system is a compilation of cells that circulate around the body to recognize, attack, and eliminate foreign invaders. The lining of cells, known as the membrane, contains fats and proteins that regulate immune system activity. During microorganism invasion, these fats and proteins in the membrane help the immune system soldiers navigate through our organs towards the microscopic enemy. The immediate immune response to foreign matter is known as acute inflammation. To prevent unwanted chronic inflammation, different proteins in the cell’s membrane will stop the immune system from continued combat.

To date, quite a few groups have reported an association between dietary omega-3 fatty acids and decreased inflammatory related diseases. From these studies, omega-3 fatty acids were given the all-important name “anti-inflamatory” agents. This is turn prompted many health agencies and doctors to recommend increased intake of omega-3 fatty acids. No one actually understood, however, why omega-3 fatty acids prevented inflammation (Am I the only one who finds blind recommendations a little scary?)! How many pills and supplements do you take without understanding what they do in your body? Sadly, those who recommended them in the first place might not understand either.

Not to worry, Samantha P. Tull from the University of Birmingham in the United Kingdom recently reported a possible link between EPA, the type of omega-3 fatty acid found in fish, and anti-inflammation. Tull’s team studied endothelial cells, the type of cell that lines the inside of blood vessels and the very layer that separates the immune system from our organs. Additionally, Tull examined the neutrophil, a front-line soldier activated in an immune system response.

Tull’s group exposed endothelial cells to EPA and found that membranes readily incorporated the new fatty acid. Upon close observation, Tull found that endothelial cells that were not exposed to EPA allowed neutrophil passage through the cell layer, while EPA-treated endothelial cells opposed neutrophil passage. Additional experiments showed that EPA acts in the membrane to block proteins that are used to help neutrophils migrate through the endothelial cells.

Tull’s data supports the idea that omega-3 fatty acids serve as anti-inflamatory agents. One might hypothesize that this essential nutrient treats inflammatory-related diseases by stopping neutrophil migration from the blood stream into inflamed tissues. Without migration of neutrophils through blood vessels into organs, the inflammation process cannot be sustained and eventually subsides.

Although Tull’s study is convincing, her experiments were performed in a petri dish. To validate her interpretation of the data, a look at the effect of omega-3 fatty acids in a mammalian model, such as mouse or rat, is warranted. Regardless, it is quite satisfying to have a potential explanation as to why omega-3 fatty acids are anti-inflammatory.

The bottom Line: EPA, a type of omega-3 fatty acid found in fish, potentially acts as an anti-inflammatory agent by stopping excess migration of cells from the immune system into our organs. Perhaps I’ll have fish for dinner tonight!


Reference: Tull SP, Yates CM, Maskrey BH, O'Donnell VB, Madden J, et al. 2009 Omega-3 Fatty Acids and Inflammation: Novel Interactions Reveal a New Step in Neutrophil Recruitment. PLoS Biol 7(8): e1000177. doi:10.1371/journal.pbio.1000177