Expert Celebrities Lull Our Brains into Buying the Goods They Peddle

You switched on the TV and a commercial is playing. Maria Sharapova is in the midst of delivering a top spin to the corner of the opposite court. Clad in clothing with the distinctive swoosh logo as part of her multi-million dollar endorsement deal with sports giant NIKE, she smiles as the commercial ends with the wording - Just do it. 

The company is hoping that the next time you go shopping for tennis clothes; NIKE is where you go. 

Why do companies rush to sign endorsement contracts with the next big thing in sports and entertainment? What is it about celebrity endorsement that persuades us to buy a product? 

While researchers have long known that we are more likely to be persuaded by information coming from highly credible sources than low credibility sources, the underlying brain mechanisms remains unclear.

Using functional magnetic resonance imaging (fMRI), which allows researchers to derive a measurement of neural activity from blood flow in the brain, new research by Dutch scientists suggest that what makes these advertisements so compelling and successful is that merely seeing a celebrity expert paired with a product is sufficient to induce a stronger memory and positive attitude towards the product.

In the study, 24 female students (mean age 21.8 years) had their brains scanned while being shown pictures of celebrities and objects in a sequential manner. They were asked to indicate whether a given celebrity was linked with the subsequent object. For example, participants were shown a picture of former world number 1 tennis player Andre Agassi followed by a picture of a sports shoe and asked if there was a relationship between the two.

The next day after the brain scan, the participants were asked to rate the celebrities’ expertise with the object. Their attitudes and memory of the objects were also assessed and the researchers found that objects that were perceived to be presented by an expert celebrity were more memorable and also elicited a more favorable attitude.

Brain imaging data revealed that participants showed greater left-sided brain activity in areas associated with semantic processing when the celebrities were paired with objects that they were perceived to have expertise in than when they were paired with non-expertise objects.

The researchers argue that the greater left-sided brain activity meant that participants were engaging in deeper processing of the appropriately paired celebrities and objects which resulted in better subsequent memory for the objects.

Greater relative activity in the hippocampus and parahippocampal gyrus – brain areas that are known to be involved in memory also supported their claim that appropriate celebrity expertise – object pairs were driving the memory effects of these objects.

This finding thus suggests that we would remember a golf club better if Tiger Woods was swinging it in a commercial compared to seeing UK celebrity chef Jamie Oliver putting on the green.

But does remembering the objects better translate into actual dollars or are companies just wasting their money engaging celebrities to market their products? The study suggests that spending millions on celebrity endorsement is a sound investment.

Participants indicated that they were more likely to purchase the product when it had been paired with an appropriate celebrity expert. Greater celebrity expertise with the product also increased activity in the caudate nucleus – the brain area involved in trust and reward processing. 

Even though it is unclear whether male brains would show similar patterns at this juncture, the researchers touted the study as “the first steps towards a neuroscientific model of persuasion” and more research is expected to be on the way to improve our understanding of what makes us buy the things we buy.

So just remember, the next time you step into a NIKE store looking for that hot tennis skirt, it is unlikely to be just a happy accident.

Klucharev, V., Smidts, A., & Fernandez, G. (2008). Brain mechanisms of persuasion: how 'expert power' modulates memory and attitudes Social Cognitive and Affective Neuroscience, 3 (4), 353-366 DOI: 10.1093/scan/nsn022

On Evolutionary Explanations of Restrictive Eating Disorders, and the Value of Radical Ideas

Evolutionary theory posits that every psychological, behavioural and physical trait expressed by an organism was selected for by aiding the organism in its survival and/or reproduction, and therefore had a functional purpose for existing at some point in evolutionary time. A trait could never exist if the environment was not conducive for its expression (i.e. hinders the organism in survival or reproduction).

By this logic, it might therefore be reasonably assumed (however inconceivably) that there could have been some adaptive function for the existence of anorexia and bulimia at some point in our evolutionary history. They are annoyances in our modern world because there could be a mismatch between its usefulness in the ancestral past and the environment today.

There are at least five major evolutionary explanations for restrictive eating disorders, each with its own flaws, as outlined by Dr Igor Kardum and colleagues from the University of Rijeka in a 2008 paper reviewing evolutionary accounts of anorexia and bulimia, namely (1) the reproduction suppression hypothesis (Wasser & Barash, 1983), (2) the model of parental manipulation (Voland & Voland, 1989), (3) the sexual competition hypothesis (Abed, 1998), (4) the adapted to flee from famine hypothesis (Guisinger, 2003), and (5) the combined concepts of 'social attention holding power' and the 'need to belong' (Gatward, 2007).

The most palatable (and, thus, conventional and popular) idea tends to revolve around competition among females catalysed by the media (sexual competition hypothesis). It is the notion that in wealthier societies, to be able to resist food is seen as a mark of having high status, while in poorer societies, to be able to get food is conversely the indicator of high status; thus anorexia is more prevalent in modernised societies while relatively larger-sized females are exemplified as beautiful. This is propagated via media imagery.

I will not go into detail with all the ideas as it can get rather technical, but in particular I wanted to point out two radical ideas put forth that, while still works-in-progress, were really interesting and reflective of creative, convention-defying attempts to think of new ways to consider this issue.

In particular, I thought Voland and Voland's (1989) model of parental manipulation interestingly attempts to account for why eating disorders tended to happen more with wealthier, higher class individuals. This model draws on kin selection theory and asserts that anorexia may be adaptive (useful) insofar as it increases an anorexic's helping behaviour to her own kin's survival and reproduction while suppressing her own reproductive success (because anorexia leads to a decline in fertility). Non-evolutionary research in the 70s showed that members of anorexic families possessed mutually overprotective attitudes, and anorexic individuals tended to worry constantly about the well-being of their families. In the ancestral past when families were larger, anorexic female helpers could suppress their own reproduction and therefore divert their own resources towards helping collateral kin, leading to greater inclusive fitness (genes belonging to family members). This sets the precedent for some interesting speculations. The model of parental manipulation suggests that anorexia is actually somehow exacerbated by parental influence. Many studies report significant correlations between dominant and overprotective mothers and the probability of anorexic reactions of their daughters. Anorexia reduces a female's fertility and hinders her from bearing additional offspring. Additionally, when a daughter is overprotected and dominated by her mother, her ability to find a mate is also reduced. In wealthy families, males are the more valuable sex as they have the resources to attain more mates. By inducing anorexia (thereby restricting the reproduction of daughters and also reducing their food intake), especially for families in higher societal strata and class, parents can then concentrate investment potential towards sons, who in wealthier families have higher reproductive value.

The next radical idea is Gatward's (2007) combined concepts of 'social attention holding power' and 'the need to belong'. 'Social attention holding power' is defined as an individual's ability to hold attention and gain investment from other members of the group, and this concept is closely related to the degree to which a person feels in control. Naturally, higher status individuals hold more social attention in their group and feel more in control. The need for belonging to a group is a fundamental human need, as ancestors who did not belong to any group were unlikely to survive for long in the harsher environments of the past. Because survival depended on belonging to a group, people had to compete for resources and this competition could lead to exclusion, if one wasn't careful. Anorexia might therefore have been adaptive in the past to prevent competition for food and resources, as well as compete in a more nuanced manner for status (a reference to the more conventional sexual competition hypothesis outlined above), thereby promoting group harmony and reducing the likelihood that one might get expelled. I would personally go on to speculate that in our modern society (essentially functioning and subconsciously perceived as a really large group), nobody feels like the highest status female who doesn't need to conform to restrictive eating disorder, because there is an implicit assumption that the highest status female is the one they see artificially created by the media. So everyone else who feels subordinate will increase her tendency to engage in restrictive eating disorder, an adaptation brought on by the need to maintain the large group's social harmony.

These are certainly radical theories that need to withstand more empirical testing, but it is exciting to read them because they represent interesting attempts to get away from more conventional and acceptable ideas that do not necessarily get us very far, as evidenced by the fact that many extant theories on the causes of eating disorders still have ambiguities and gaps. Of course, there has to be a deal of initial plausibility, lacking which we would just think the idea is quack. But science is ultimately pushed by great thinkers with ground-breaking insights.

On a concluding note, the authors of the review paper highlight one consistent element found among all proposed evolutionary theories of restrictive eating disorders - response to threat. All the major evolutionary explanations can be reasoned as a form of response to threat (to survival and/or reproduction) that leads people (especially females) to develop symptoms of eating disorders. This independently corroborates research linking eating disorders with feelings of insecurity and need for control.



Abed, R. (1998). The sexual competition hypothesis for eating disorders British Journal of Medical Psychology, 71 (4), 525-547 DOI: 10.1111/j.2044-8341.1998.tb01007.x

Gatward N (2007). Anorexia nervosa: an evolutionary puzzle. European eating disorders review : the journal of the Eating Disorders Association, 15 (1), 1-12 PMID: 17676667

Guisinger S (2003). Adapted to flee famine: adding an evolutionary perspective on anorexia nervosa. Psychological review, 110 (4), 745-61 PMID: 14599241

Kardum, I., Gračanin, A., & Hudek-Knežević, J. (2008). Evolutionary explanations of eating disorders Psychological Topics, 17 (2), 247-263.

Voland, E., & Voland, R. (1989). Evolutionary biology and psychiatry: The case of anorexia nervosa Ethology and Sociobiology, 10, 223-240

Wasser, S., & Barash, D. (1983). Reproductive Suppression Among Female Mammals: Implications for Biomedicine and Sexual Selection Theory The Quarterly Review of Biology, 58 (4) DOI: 10.1086/413545

Sexual Strategies Underlie Religious Inclinations

The positively correlated associations between religiosity (of a Christian-centric nature) and low levels of promiscuity and high levels of abstinence and marriage-centricity are generally quite clear enough. We often see that religion seeks to suppress sexual promiscuity through its doctrines that promote a monogamous sexual reproductive strategy characterized by low promiscuity, exclusive heterosexuality and high premiums on marriage and fertility.

Intuitively, we might guess that our sexual inclinations owe to how much exposure we have towards our adopted religion. Thus, we might, quite reasonably, suppose that someone who regularly attends Sunday school and comes from a religiously devoted family with staunch practices in the home would more likely be shaped into a long-term mating, marriage-inclined and sexually abstinent person, than someone who does not observe those traditions and customs. Indeed, it was found that treating premarital sex as sinful creates incentives to marry earlier, and condemning abortion and birth control as sin makes people have children.

However, when we look at the US, which is considered the most religious nation compared to its other western counterparts, what is fascinating is that it is remarkably evenly divided - approximately 42% of adults never attend religious services, 18% attend intermittently, and 40% attend services regularly (information from the 2006 US General Social Survey).

This suggests that, while a country may adopt non-secular values to predominantly guide its affairs and inform its citizens, not everyone may agree or be inclined to go along with those values. In the case of the US, this divide is exemplified by the emergence of the Religious Right and the Liberal Left.

As evolutionary psychologist Kenrick (2011) colloquially and aptly states it, "the prototypical member of the Liberal Left ... may wait until at least the end of college before marrying and beginning to have children and then may delay even a few years longer to go to graduate school, law school or medical school. Because the human ability to resist sexual urges has a hard time outlasting all that postponement, these folks do not like the Religious Right's attempts to impose rules against premarital sex [or] tools of family planning. ... [The Liberal Left pose a problem for the Religious Right] because a large number of sexually loose young people playing the field threatens to disrupt the strict system that religious folks have set up to enforce and reinforce family bonds."

Working on that insight, Weeden, Cohen and Kenrick (2008) proposed the reproductive religiosity model - instead of religiosity affecting our mating strategy (whether we can be promiscuous short term maters, or should be committed, abstinent long term maters), it is instead our mating strategy that makes us calculate the costs and benefits of adopting a religion, or remaining devoted to our current religion. If I am unable to bear the cost of abstinence from premarital sex and I do not want to marry early, my exit strategy is to drop my impeding religion.

By analyzing data from two large sources - 21,131 respondents in the 2006 US General Social Survey and 902 undergraduate students who were probed about their family plans, sexual attitudes, religious attendance, and moral feelings about issues ranging from lying to stealing - it was found that the strongest predictors of religiosity were factors related to sexual and family values. While there were other typical variables that predicted for religiosity, such as being female, older, or a non-drinker, and being high in conscientiousness and low in sensation-seeking, statistically controlling for sexual and family value items made the links between these other typical variables with religiosity disappear. In other words, everything we might have assumed to be associated with religiosity can be boiled down to sexual and family values. The study by Weeden, Cohen and Kenrick (2008) thus provide evidence that, on average, whether we are religious or not in the first place depends on how promiscuous we want to be.

If that causal link is true, could it be possible to manipulate people's mating strategy and thus alter their religiosity, in the psychology laboratory no less?

A study by Li, Cohen, Weeden and Kenrick (2010) sought to test that idea. A cleverly deceptive cover story and elaborate experimental design was used, but in brief, participants were ultimately made to look at either desirable members of their own sex or desirable opposite sex members (such a priming method has been found to be effective in conjuring either a mating motivation state - when we check out attractive opposite sex persons - or a mating threat state - when we are made to look at attractive same sex persons). Participants were also made to fill out a survey on the pretext of finding out their attitudes; embedded in the survey were questions pertaining to religiosity.

The results showed that when the men looked at attractive ladies and when the women looked at attractive guys, there was no discernable effect of mating motivation on religiosity. Interestingly, the laboratory setting was unable to capture any desire to give up religion when participants were made to feel more motivated to mate. However, what was more interesting was that, instead, participants who looked at attractive members of one's own sex expressed greater belief in religion. Being primed with mating insecurity leads people to become more religious.

We see support here for the classic antagonism played out between the Religious Right and Liberal Left. Once again, Kenrick (2011) states it best, so he will be quoted here: "When you become aware that there are a lot of highly attractive mating competitors out there, it reduces the perceived benefits of playing a fast and loose mating strategy ... For women, a lot of attractive competitors means less attention from the attractive men who might provide good genes, and fewer fellows vying to support your offspring. For men, on the other hand, an abundance of especially handsome and available guys means that if you are playing the field, you may be playing with yourself for most of the game. Under circumstances of limited opportunities, any normal person - who does not look like a fashion model - could benefit from the religion-based supports for monogamy."

This is not to say that religious practices do not reduce sexual promiscuity - all other things equal between two people who are subjected to different levels of religious piety, we would expect the one who has been told that things like premarital sex are sinful would be less inclined to do the deed. However, these studies highlight another crucial direction in the causation, that sometimes people may choose how religious they want to be based on the perceived cost of carrying out sexual "transgressions" under the religion they are affiliated to. And at the heart of the differing values the Religious Right and the Liberal Left promote, each camp is sustainable because they encourage and reinforce different mating patterns; there is antagonism only because a clash of these value systems is highly disruptive to each side's foundations for their own reproductive status quo.



Weeden, J., Cohen, A., & Kenrick, D. (2008). Religious attendance as reproductive support Evolution and Human Behavior, 29 (5), 327-334 DOI: 10.1016/j.evolhumbehav.2008.03.004

Li YJ, Cohen AB, Weeden J, & Kenrick DT (2010). Mating Competitors Increase Religious Beliefs. Journal of experimental social psychology, 46 (2), 428-431 PMID: 20368752

We're back!

We're back! After a long hiatus as a resultant mish-mash of graduation, traveling and everything else in between, Psychothalamus is ready to churn out more interesting reads once again.

Before that, we thought it'd be nice to share with our readers what we've been up to and where we're headed.

Jose wasted no time hitting the road the moment his final finals ended. Within hours of his last examination paper, he was jetting off on his graduation trip from Singapore to Ho Chi Minh City. Over the course of some very crazy 45 days, Jose traveled from Ho Chi Minh City to Phnom Penh, Siem Reap, Bangkok, Vientiane, Vang Vieng, Nong Khai, Delhi, Agra, Jaipur, Kathmandu and Pokhara. The traveling didn't end there though; upon settling down back home, he was off again to Washington DC to attend the 2010 APS Conference, where he presented a poster on the findings of his Honours Thesis. Officially graduated, Jose will be spending the next year working on a few projects at the Behavioural Sciences Institute of Singapore Management University before applying for graduate studies.

To celebrate getting admitted into graduate school, QH travelled over 6000km by rail and road on his epic tour of China, spanning 28 days, visiting a grand total of ten UNESCO sites. He suffered a severe bout of Montezuma's revenge on the trip and came back with a 100RMB counterfeit currency in his wallet. He is now trying to get himself fired up for the long road ahead as he prepares to pursue a PhD in cognitive neuroscience in the fall of 2011.

Shawn did not have all that much money to travel, so he satisfied his travel cravings with a three-day trip to Japan, of which two days were spent in Akihabara, the otaku mecca of anime and videos. The rest of his time was filled up by compulsory physical training to maintain his fitness levels for the Singapore Army, and preparation for his PhD at the National University of Singapore Graduate School for Integrative Sciences and Engineering, where he will be combining his love for Neuroscience and Genetics.

A Professional Distaste for Administration?

Ever had to deal with difficult administrative personnel pressing you to adhere to some (@?$&#!!) company policy? Regardless of your own personal experiences, the euphemisms abound for administration (the powers that be, the higher ups, paper tigers, tai chi masters, etc) suggest that the administrative department is difficult, bureaucratic, meddling and restrictive. As a young employee joining a company, one of the first few things an attached mentor often shares in a "between you and me" moment is his or her gripe with administrative policy.

Administrators do have a crucial role to play in organisations. They set the boundaries and parameters within which organisation members are allowed to play. Administrators are often (either perceived as or truly) detached from the idealisms of the organisation, as their primary function is to regulate the workflow and processes of the organisation, in the hopes of ensuring that certain outcomes (often mundane ones) are achieved, such as neater procedures, safety, transparent accounts, etc. It therefore often makes sense to employ administrators who might not share the same essential pursuits of the other members of the organisation, so that a more objective and strict execution of implementations, policies, rules and regulations can result. Enforcing the red tape, so to speak.

How do people respond to difficult, strict and/or assertive administrators, particularly when those administrators are attempting to necessitate certain policies? According to a 2009 study done by Hekman (University of Wisconsin-Milwaukee) and Steensma, Bigley and Hereford (University of Washington), our likelihood of responding positively to administrative pressure (such as to adopt new work behaviour) depends on the degree to which we identify either with our profession or our organisation.

Formalising administrative pressure as Administrative Social Influence (ASI), the authors found that professional employees were most receptive to ASI to adopt new work behaviour when they strongly identified with the organisation and weakly identified with the profession. Conversely, ASI was counterproductive when professional employees identified strongly with the profession while identifying themselves weakly with the organisation.

The authors showed this by looking at a sample of about 200 primary care professionals from a large, non-profit health maintenance organisation. ASI was carried out to get the health professionals to adopt a new internet-mediated email-based technology called secure messaging, designed to reduce patient demand for office visits which in turn lowers expenses. Compliance with ASI was thus the measured dependent variable - whether the health professionals responded promptly (within 24 hours) to secure messages from their patients. The health professionals' organisational and professional identification was measured, and their identification was correlated with their tendency to follow through on the call to use secure messaging. Additionally, their perception towards ASI pressure was measured as well.

The results of their study showed that the more health professionals thought of themselves as part of an organisational team (strong organisational identification), the more they were likely to comply with new work behaviours solicited via ASI, and the less likely they were to perceive ASI as pressuring. The authors cite evidence that administrators are generally seen as "organisational guardians" (Freidson, 2001) and as "prototypical organisational members" (Golden et al., 2000), and when organisational identification is high, "professional employees’ sense of self is tied closely to a group that includes administrators. As a result [...] organizational identification leads professional employees to believe that organizational administrators are like them and on their side." On the other hand, people who identify strongly with their profession care very much about their professional responsibilities and tend to be skeptical of the interests and agenda of administrators who appear to care more about efficiency and profitability rather than high quality service. So, when health professionals have a greater sense of oneness with the nature of their profession rather than the bigger organisation they work within (strong professional identification), they were less likely to comply with new work behaviours solicited via ASI, and were also more likely to perceive ASI as meddling and demanding.

The authors thus conclude that ASI is effective only in limited contexts (i.e., only when one type of identification was relatively high while the other was relatively low). While the authors prudently keep away from commenting on their personal feelings towards "the powers that be", their study implies that organisations should consider encouraging greater social identification of their employees with the organisation if they want to increase employee compliance with new implementations. Might prove less of a problem with professional administrators...


Hekman, D., Steensma, H., Bigley, G., & Hereford, J. (2009). Effects of organizational and professional identification on the relationship between administrators’ social influence and professional employees’ adoption of new work behavior. Journal of Applied Psychology, 94 (5), 1325-1335 DOI: 10.1037/a0015315
Golden, B., Dukerich, J., & Fabian, F. (2000). The Interpretation And Resolution Of Resource Allocation Issues In Professional Organizations: A Critical Examination Of The Professional-Manager Dichotomy* Journal of Management Studies, 37 (8), 1157-1188 DOI: 10.1111/1467-6486.00220

Freidson, E. (2001). Professionalism: The third logic. Chicago: University
of Chicago Press.

Sacred Values as Heuristics

Can being faced with a decision involving morals be a good thing? Research has shown in the past that morally-laden decisions are perceived as difficult and unpleasant. Therefore, conventional wisdom suggests that people would react characteristically when faced with decision-making with moral considerations, such as avoiding being placed in a position to make moral decisions, or effortfully spending more time deliberating over difficult moral decisions.

However, perhaps there's more to it than meets the eye, and Hanselmann and Tanner from the University of Zurich think so. In a very concise study, Hanselmann and Tanner (2008) sought to show that the involvement of moral issues and values can, instead, actually facilitate our decision-making. By invoking what are known as sacred values (absolute and inviolable values), we may end up spending less time thinking about the dilemma simply because an option that has sacred value makes us think that it cannot be compromised.

Every dilemma or decision involves some extent of trade-off. The authors conceptualized three types of trade-offs for the study:

Taboo trade-off
a situation that pits a secular value (i.e. a value that does not hold moral worth) against a sacred value

Tragic trade-off
a situation that pits two sacred values against each other

Routine trade-off
a situation that pits two secular values against each other

One might thus think of a routine trade-off in the case of a typical job dilemma. Faced with employment in Company A vs Company B, one might consider trading off mundane items such as salary, distance or working environment. On the other hand, an extreme (though commonplace) example of a tragic trade-off would be to decide whether to save one's parent or an offspring instead in the event of a fire.

In the first experiment, 84 students from the University of Zurich were presented with three scenarios representing a taboo, tragic or routine trade-off. Each scenario provided a choice between two options. An example of a taboo trade-off scenario was as follows:

Imagine that you are the president of the local authority of a village that has been severely affected by a flood. The local authority is discussing whether to invest a considerable amount of the annual budget in improved flood protection measures. In this case, however, the village would have to forego a planned facelift for the village square. As president, you have to decide between the improvements in flood protection (option 1) and the facelift for the village square (option 2).

Participants were then asked to rate how they felt about the decision, such as how emotionally negative the decision was and how difficult it was to decide on an option. The following results were gathered:

As can be seen, the difficulty of decision-making was lowest when sacred values were pitted against secular values, showing that, although decision-making involving some degree of moral choice is still emotionally unpleasant, it can lead to easier decision-making. A second experiment, which was a more complex (with multiple traits to access decision difficulty and affectiveness) but fundamentally similar experiment, was conducted and the results were replicated.

Tetlock (2003) had assumed that the mere contemplation of trade-offs that involve sacred values elicits distress and disturbance. There could very well be an adaptive or functional purpose to our negative perception of moral choices which makes us acutely aware that compromising on sacred values can have adverse consequences. In a sense, we are psychologically 'punished' for even contemplating the trade-off of sacred values, so let alone act against our instinct to preserve sacred values. These findings thus suggest that reliance on sacred values may therefore work as a heuristic that we use to increase the efficiency of our decision-making.

Martin Hanselmann, & Carmen Tanner (2008). Taboos and conflicts in decision making: Sacred values, decision difficulty, and emotions Judgment and Decision Making, 3 (1)

Tetlock, P. (2003). Thinking the unthinkable: sacred values and taboo cognitions Trends in Cognitive Sciences, 7 (7), 320-324 DOI: 10.1016/S1364-6613(03)00135-9

Existential Neuroscience

Is it reasonable to fear death? If you agree with Lucretius, you will say no. In what is known as the Symmetry Argument, Lucretius contends that that the time before our existence is similar to the time of our future non-existence. And since we do not fear the time before we existed, it is not reasonable to fear our future non-existence i.e. death. (See Rosenbaum, 1989 for a more detailed exposition)

However, even if you concede to Lucretius’s argument, the fact remains that the awareness of our mortality generates a significant threat to our psychological well-being. A large corpus of research on terror management theory details how mortality saliency affects our self-esteem, worldview, among others.

In a recent fMRI study, Quilin and colleagues (2011) extends our knowledge on terror management theory by exploring the neural correlates of mortality salience. They were interested in the activity of the amygdala, rostral anterior cingulated gyrus (ACC), ventral tegmental & caudate nucleus (CN).

In this within-subjects experiment, thoughts of death were induced in the participants by requiring them to agree or disagree with a statement such as I am afraid of a painful death. Statements about dental pain were used in the control condition.

Results

The authors found higher activations in:

• Right amygdala
• Left ACC
• Right CN

They suggested that the activations in the amygdala and ACC may indicate ‘non-conscious, latent markers of threat aroused by mortality salience’ and that further investigations may reveal the role of the CN in regards to the defensive mechanisms that we employ against mortality threat.

This area seems promising to me and more research needs to be done to help us better understand how we deal with threats of mortality. It would also be interesting to look at how religious affiliations affect the way the brain deal with existential fears. If indeed 'mortality threats functions as a potential for anxiety rather than as experienced anxiety', what can neuroimaging techniques tell us about whether believing in a higher being help us deal with the potential or experienced anxiety resulting from mortality threats?



Quirin M, Loktyushin A, Arndt J, Küstermann E, Lo YY, Kuhl J, & Eggert L (2011). Existential neuroscience: a functional magnetic resonance imaging investigation of neural responses to reminders of one's mortality. Social cognitive and affective neuroscience PMID: 21266462

Rosenbaum, S. (1989). The Symmetry Argument: Lucretius Against the Fear of Death Philosophy and Phenomenological Research, 50 (2) DOI: 10.2307/2107964

Beauty-is-Good Stereotype in the Brain

Leo Tolstoy once said, “It is amazing how complete is the delusion that beauty is goodness.” And how complete is this delusion? In a recent study, Tsukiura & Cabeza (2011) provides an insight into this question by investigating the neural mechanism underlying the Beauty-is-Good stereotype. They were interested in the activity of the medial orbito frontal cortex (associated with positive stimuli, reward processing etc); the insular cortex (associated with negative stimuli, punishment processing etc) and the interaction between these two regions.

This fMRI study required participants to engage in 3 different tasks:

1. Face attractiveness rating (beauty judgment task)
2. Action goodness rating (moral judgment task)
3. Brightness rating (control condition)

The 3 tasks. Click to enlarge

Conforming to their hypothesis, the authors found that activity in the mOFC increased linearly as a function of both attractiveness and goodness rating. Activity in the insular cortex also decreased linearly as a function of both types of ratings. In both regions, the strong correlation between the activations caused by both judgments also supports the idea that similar neural regions are engaged when we are processing attractiveness and moral goodness.

Furthermore, the negative correlation between right mOFC and right insular cortex provides support for the “dual process hypothesis” of the Beauty is Good stereotype in that we display both a positive bias of attractiveness as being good and a negative bias against unattractiveness as being bad.

That is to say, the stereotype is driven by two opposing mechanism whereby we tend to think that an attractive person is more moral and an unattractive person is less moral, rather than a singular bias towards attractiveness or unattractiveness.

Click to enlarge

Our delusion that beauty is goodness then appears to have been built into how our brain processes both type of judgments and the completeness of this delusion may surprise even the great Leo Tolstoy.

Tsukiura T, & Cabeza R (2011). Shared brain activity for aesthetic and moral judgments: implications for the Beauty-is-Good stereotype. Social cognitive and affective neuroscience, 6 (1), 138-48 PMID: 20231177

When it's moving, it's hard to see it changing.

Change blindness is a phenomenon whereby people fail to detect sizable changes in a visual scene. This can occur even when they are actively trying to locate the change (Simons & Ambinder, 2005). If you are unaware of this phenomenon, you can go to UBC's psychology department where they have some interesting video examples.

In a new study, Suchow & Alvarez (2011) demonstrates a novel visual illusion whereby motion induces failure to detect change - or what they call 'silencing'. Look at the video embedded below. Initially, the dots are visibly changing in colour but once the rotation begins, the dots appear to stop changing or at least appear to change at a slower rate. Additional video demonstrations looking at brightness, size and shape can be found here.

Motion silences awareness of color changes from Jordan Suchow on Vimeo.

They found that the faster the rotation, the slower the dots appear to change (i.e. stronger silencing).

Click to enlarge

In an additional set of experiments, they further determined that motion on the retina and not motion in space is responsible for silencing. Pretty nifty visual illusion huh.

*We are glad to have our first post based on a reader article submission and welcome additional submissions. Spread the word!

Suchow JW, & Alvarez GA (2011). Motion Silences Awareness of Visual Change. Current biology : CB PMID: 21215632
Simons, D., & Ambinder, M. (2005). Change Blindness. Theory and Consequences Current Directions in Psychological Science, 14 (1), 44-48 DOI: 10.1111/j.0963-7214.2005.00332.x

Birth Order Influences the Formation of Long-Term Relationships

134 years since Francis Galton opened the birth order effects debate by observing that first-born sons and only sons were over-represented among English scientists, controversy has shrouded the issue such that we haven't quite gotten past whether birth order effects exist or not, let alone properly consider what they are or how they work.

Some scholars assert that the lack of conclusive evidence is due to methodological biases that may allow the researcher to find the result that he or she is looking for. So, in that sense, a researcher who seeks to confirm that the birth order effect exists may find it just as well as a researcher who seeks to disconfirm it might.

In Birth Order Effects in the Formation of Long-Term Relationships, Hartshorne, Salem-Hartshorne and Hartshorne seek to probe the birth effect in a manner that is as methodologically neutral as possible by simply determining if there are any correlations between the sharing of birth order and the likelihood of long-term relationship formation. Their results provide new research material that weighs in favour of the presence of birth order effects, though what drives this effect is still speculative.

By drawing on a sample of 900 US undergraduate students, the researchers found that people are more likely to form and be in long-term relationships, both friendly and romantic, if they share the same birth order than would be expected by chance. For instance, if I were a first-born child, the likelihood of me being close friends with another first-born child is higher than the likelihood of me being close friends with another second- or third-born child. This tendency was also found for romantic partners.

A second and similar web-based study was conducted which gathered responses from American participants (1,911) as well as participants from other parts of the world (713). Similar results were garnered. There was no significant difference detected between American and non-American respondents, suggesting that birth order effects on long-term relationships are not culturally variant.

The researchers also controlled for socioeconomic status and size of family, which is a progressive extension from other earlier studies. This eliminates the confounds of number of siblings one has and the socioeconomic class one belongs to, which can potentially influence one's development because it is a commonly known social phenomenon that wealthier and upper class families tend to have less offspring.

The authors surmise that birth order underlies personality traits and having the same birth order results in greater compatibility between personality types, leading to the formation of closer bonds in both friendships and romantic relationships.

Joshua K. Hartshorne, Nancy Salem-Hartshorne, and Timothy S. Hartshorne (2009). Birth Order Effects in the Formation of Long-Term Relationship Journal of Individual Psychology, 65 (2)

Detecting facial emotions: Women vs Men

Do women really recognize facial emotion better than men? Existing literature on the subject remains contradictory with some studies showing a female advantage (albeit with small effect sizes) and others failing to find any gender differences. Hoffman and colleagues (2010) suggest that expression intensity is an important factor mediating gender differences in recognizing emotions and that while women do recognize facial emotions better than men, this advantage only exists for subtle emotional facial expressions.

Using a facial expression morphing tool (FEMT), they manipulated the intensity of the emotional facial expression for their stimuli. Looking at the 40% intensity, I must say that it is in fact pretty hard for me to identify.

click to enlarge

Conforming to their hypothesis, they found that women indeed only recognize subtle emotional expression better than men but not when full-blown emotions are displayed. Decreased emotional intensity negatively affected the judgments of male participants more than that of female participants.  

But of course accurately detecting facial emotions is just the first part of the equation, whether you deal with it adequately is another thing altogether - especially when they are subtle. 

Hoffmann H, Kessler H, Eppel T, Rukavina S, & Traue HC (2010). Expression intensity, gender and facial emotion recognition: Women recognize only subtle facial emotions better than men. Acta psychologica, 135 (3), 278-83 PMID: 20728864

Early Life Experience and Neurodegeneration

Although some studies have found that early life environmental factors can affect our vulnerability to neurodegenerative diseases such as Alzheimer’s disease in later life, the underlying neuronal mechanisms of such vulnerability are not well understood. By looking at post mortem rhesus monkey brains, Merrill et al. (2011) finds an association between early life experience and subsequent risk of exhibiting neurodegeneration in later life.

In the study, β-amyloid plaque density and synaptophysin immunoreactivity in the brains of the rhesus monkeys that had lived in standard sized cages VS small cages (29% smaller than standard cages) for the first 15 years were compared. Young monkeys were also used as a basis for comparison.

β-amyloid plaque density

β-amyloid deposition has been established as the central cause of Alzheimer’s disease (Hardy & Allsop, 1991). The researchers found that monkeys that were housed in small cages had higher β-amyloid plaque density and amyloid load in the superior temporal gyrus compared to monkeys that were housed in standard sized cages. Young monkeys had no detectable amyloid deposition and were not graphed.

click to enlarge

However, I think the β-amyloid density results should be taken with a pinch of salt. Although the authors did mention that there is considerable individual variation - which parallels data in human studies, the effects seemed to be heavily driven by the monkey which had almost 140 plaques per mm square. Also, there were only 5 monkeys in the small cage condition and 3 of them appear to have comparable β-amyloid density levels. The authors also did not include individual data for the superior temporal gyrus amyloid load graph but the large error bar again suggests significant individual variations.

Synaptophysin Immunoreactivity

Monkeys reared in small cages also showed a reduction in synaptophysin immunoreactivity - a presynaptic marker, in the superior temporal gyrus. This indicates a decrease in synaptic density and activity which has been linked with cognitive impairment in Alzheimer's disease.

All said, the value of the study lies in their finding “early life experience is associated with degenerative change in the non-diseased aged brain” (emphasis theirs). Therefore, even in normal aging, our early life experiences can affect the rate of neural degeneration. Remind me to get a bigger crib for my child in the future.


Merrill DA, Masliah E, Roberts JA, McKay H, Kordower JH, Mufson EJ, & Tuszynski MH (2011). Association of early experience with neurodegeneration in aged primates. Neurobiology of aging, 32 (1), 151-6 PMID: 19321231

Effects of sleep on Remembering to Remember

Prospective memory is a class of memory that is unique in that it involves the future rather than the present or the past. Various examples of prospective memory include remembering to buy a pet monkey, or remembering to break up with your girlfriend or remembering to do that blasted thesis that you have been putting off for the umpteenth time. Hence, some researchers have called it the act of "remembering to remember" (Winograd, 1988). Although prospective memory is quite important for daily functioning and goal fulfilment, research on it has been quite sparse in comparison to other forms of memory. One big question remains: how do we remember to remember? Do we devote some resources to maintain this intention? Or is it maintained without anything being devoted to it?

You know you want it.

One theory of prospective memory suggests that prospective memory can be both effortful and automatic. One way in which prospective memory can be automatic is when cues in our environment alert us to something we have to do. Kvavilashvili and Fisher (2007) has found that individuals often encounter cues related to a goal (eg, seeing a monkey in the magazine, receiving a text message from the girlfriend) and these cues spontaneously remind participants of their goal. Another way in which prospective memory is maintained is through conscious retrieval. Other researchers have also found that prospective memory surprisingly is better after 15 minutes than 3 minutes, one interpretation being that participants consciously retrieve and rehearse the goal prior to and up to the point when they are going to execute it (Hicks, Marsh & Cook, 2005).

One question that arises from these findings is that, what happens when we sleep on something? During sleep it appears that both automatic and effortful mechanisms are absent; we don't consciously retrieve and rehearse goals, and we aren't exposed to cues from the external environment. In such a case we might expect that prospective memory would weaken. However, given that a huge amount of literature has also shown that sleep improves memory, we might expect that sleep would improve prospective memory. These contradictory hypotheses form the basis for Scullin and McDaniel's study, "Remembering to execute a Goal: Sleep on it!" (2010)

The researchers had participants do a series of tasks (too lengthy to cover), while remembering to do a particular action at a particular time ("press the Q key when you see the word table or horse"). In one set of participants, this target came after a short delay (20 minutes) while in the long delay condition, participants were told to come back after 12 hours for another series of experiments and the target came there. The other crucial manipulation was time of day, the experiment for one set of participants was started in the morning, and the other set at night. The study was between groups, so participants were spread out across 4 conditions.

1. Short Morning Delay

2. Short Evening Delay

3. Wake Delay (from morning to night, during which time the participant was awake)

4. Sleep Delay (from night to morning, during which time the participant was sleeping)

What the researchers found was that sleeping improved the ability to remember to do something, as compared to being awake. In some of the tests, the performance was almost as good as if one was tested after 20 minutes. One important possible confound in this experiment was that the sleep and awake conditions also differed not just in amount of sleep but also when the experiment was conducted. The authors eliminated this confound by comparing performance for prospective memory during the day and night after a short delay and found that time of day had little effect.

So the results are inconsistent with the idea that sleep might undermine prospective memory by preventing conscious retrieval or exposure to environmental stimuli. It seems like prospective memory might not rely heavily on these 2 processes, as suggested by some proponents of the theory above. The implication being that if you need to remember to do something, you might as well sleep on it.

But how does sleep improve prospective memory? The authors suggest that sleep increases associative binding and that it amplifies weak goals or links. In this case, it seems like prospective memory might not be very much different from other types of memory. However the authors find that sleep improves prospective memory for only certain types of tasks, thus raising new avenues for research into different kinds of prospective memory and how they are affected by different variables.

One problem which I found in this paper was that the participants were engaging in quite an unnatural prospective memory task, in which case environmental cues present during the awake phase would not help the participant in remembering to do the task. On the other hand, in the real world, such environmental cues would be present and abundant (like seeing your thesis supervisor). So in that sense, the authors can't make the claim that sleeping improves prospective memory more than staying awake and being exposed to constant pictures of monkeys.

Another interesting idea that this paper raises is the implication of sleep on prospective memory in old people. It has been found that prospective memory is one memory that is especially impaired and gets worse with old age (they keep forgetting to get the groceries for instance). Old people also get less sleep, especially sleep of the slow wave kind. Coincidence? :)


Scullin MK, & McDaniel MA (2010). Remembering to execute a goal: sleep on it! Psychological science : a journal of the American Psychological Society / APS, 21 (7), 1028-35 PMID: 20519489

Jealousy, Turning Saints into the Sea?

"Not so long ago jealousy was considered a pointless, archaic institution in need of reform. But like other denials of human nature from the 1960s, this bromide has not aged well. ... The rock musician who wrote 'If you love somebody set them free' also wrote 'Every breath you take, I'll be watching you.'"

- Steven Pinker, on David Buss's The Dangerous Passion


Have you ever felt threatened in the presence of others you perceive to be superior to you? I recall one time when I was a teaching assistant in an introductory psychology course and, in the middle of a discussion about how jealousy is experienced when your partner interacts with someone else who appears to have higher mate value than you, an eager student asked, “Professor, but how do you know if that person has a higher mate value than you?” To which the professor smiled and cheekily said, “Oh, you just know.”

To humour the bemused student, the professor gave some scenarios. If you’re a guy, just imagine this. Some other socially dominant male is talking to your girlfriend or wife, and he’s trying to make her laugh. Worse, she actually laughs along and looks like she’s having a very comfortable and enjoyable time. If you’re a lady, imagine the reverse – your boyfriend or husband has met a younger and physically attractive woman, and now he’s the one trying to make her laugh, and she’s playing along and being very reciprocative. That creeping feeling of alarm bells and jealousy becomes just a tad more resonant.

In the dating and mating game, what exactly are those social cues that get us to be on our guard, to experience inferiority and to feel threatened? Gutierres, Kenrick and Partch (1999), researchers looking at the issue through an evolutionary perspective, explored the oft-cited mating preferences of men for physical attractiveness and women for status and social dominance, and elucidated interesting sex differences in contrast effects.

The researchers gathered data from 91 undergraduate females and 99 undergraduate males and primed the men with either physically attractive men or socially dominant men while, on the other hand, priming the women with either physically attractive women or socially dominant women. Exposure to physically attractive men or women was done by showing participants photographs of people, while exposure to socially dominant men or women was done by getting participants to read a descriptive profile of a person with high dominance.

Interestingly, their study found that men’s self-assessments of desirability were adversely affected by exposure to highly socially dominant men and were relatively unaffected by exposure to physically attractive men. Conversely, women’s self-reports of their mate value were more affected by the physical attractiveness than by the social dominance of the women to whom they were exposed. This demonstrated that humans are sensitive to the selective mate preferences of the opposite gender. If we consistently fail to match up to the quality of our rivals, this can have an effect on how we perceive our own desirability!

More recently, another set of experiments conducted by Maner, Gailliot, Rouby and Miller (2007) also looked at how our state of mind affects the level of attention we give to stimulus objects in our environment.

A total of three studies were done on undergraduate students to explore how this interacts in the scene of human mating. It was found that when participants were primed with feelings of romantic and sexual arousal, a ‘mate-search’ psychological mechanism was activated which resulted in greater attentional adhesion* towards attractive members of the opposite sex. On the contrary, when participants were evoked with feelings of jealousy (imagining a scenario that perhaps closely resembles the one that the professor had painted), a ‘mate-guard’ state of mind was primed which led to greater attentional adhesion to attractive same-sex targets.

So is jealousy simply a manifestation of insecurity? Perhaps the answer is both yes and no. Yes, because it does seem apparent that the mind is designed to experience jealousy when the environment provides feedback on where you stand. If there are many people of the same sex as you in the room who are far more attractive, that’s good reason to feel insecure especially when being evaluated by members of the opposite sex. But jealousy isn’t only just a manifestation of insecurity because it serves an important adaptive function – to alert us to the potential dangers of losing your mate, telling us to be aware of snakes and wolves in the environment, and getting us to turn on our A-game where necessary. As David Buss writes in The Dangerous Passion, jealousy is as necessary as love and sex.

* Attentional adhesion refers to how readily a person tends to a particular stimulus. In most documented cases, this is determined by measuring participants' reaction time taken to respond to stimulus.


Maner JK, Gailliot MT, Rouby DA, & Miller SL (2007). Can't take my eyes off you: Attentional adhesion to mates and rivals. Journal of personality and social psychology, 93 (3), 389-401 PMID: 17723055

Gutierres, S., Kenrick, D., & Partch, J. (1999). Beauty, Dominance, and the Mating Game: Contrast Effects in Self-Assessment Reflect Gender Differences in Mate Selection Personality and Social Psychology Bulletin, 25 (9), 1126-1134 DOI: 10.1177/01461672992512006

Buss, D. M. (2000). The Dangerous Passion: Why Jealousy Is As Necessary As Love and Sex. New York: Free Press.

Racial Differences in the Concept of Beauty

Are average composite faces the most attractive faces or are highly attractive faces markedly different from average faces? Rhee & Lee (2010) agrees with Perrett & Yoshikawa (1994) that the most attractive face is actually the average of attractive faces and that an average face; while attractive, is not the most attractive.

They also argue that previous concepts of beauty such as the divine proportion (golden ratio) are not a good measure of beauty across different races and should not be used as an overarching universal indicator of beauty. Between different races, there appears to be different characteristics that are deemed beautiful. They merged some of the most attractive female faces of African, Caucasian, Chinese and Japanese people respectively, to create the images below.

They also mentioned some of the defining characteristics of beauty for the different races.

• African: Narrow nose, smaller and more acute eyes, smaller upper lip, slender chin compared to the average African face.
• Caucasian: Somewhat masculine, narrow palpebral (eyelids) height, angulated and squared mandible (lower jaw), protruding cheek and fuller lips compared to the average Caucasian face.
• Chinese: Narrow cheek, slim and thin face, lantern jaw.
• Japanese: relatively longer face, slightly slanted eyes, sharp chin and chubby cheeks.
  

Unfortunately, they did not conduct any experimental study to compare attractiveness ratings of such faces versus other faces that are considered beautiful based on traditional morphometrics. It would also have been interesting to look at how the male composite faces would look like. 

Rhee SC, & Lee SH (2010). Attractive Composite Faces of Different Races. Aesthetic plastic surgery PMID: 20953953

Perrett DI, May KA, & Yoshikawa S (1994). Facial shape and judgements of female attractiveness. Nature, 368 (6468), 239-42 PMID: 8145822

The link between coffee and acute ischemic stroke onset

Do you drink coffee on a regular basis? I do. And what does drinking coffee have to do with acute ischemic stroke (caused by disruption of blood supply to part of the brain)? In a study published in Neurology, Mostofsky and colleagues investigated the relationship between drinking caffeinated coffee and the risk of acute ischemic stroke in the next hour.

Using a case-crossover design, each subject served as his/her own control. All the subjects were patients with a confirmed diagnosis of ischemic stroke. Coffee consumption information one hour before the onset of stroke symptoms was compared with their frequency of coffee consumption in the previous year.

They found that drinking coffee doubles your risk of ischemic stroke onset in the next hour compared to drinking other caffeinated drinks such as tea or cola; which may be due to lower concentrations of caffeine in those drinks.

When they looked at the frequency of caffeinated coffee intake in the previous week, they found that only people who were drinking ≤1 cup of coffee per day had increased risk for ischemic stroke in the following hour.

The take-home message?

• Drinking coffee temporarily increases one’s risk of ischemic stroke – especially so for infrequent drinkers (≤1 cup of coffee per day).

Well, I don’t think I’m willing to forsake my coffee just yet so I’m going to have 2 cups a day instead of my usual 1 a day.


Mostofsky E, Schlaug G, Mukamal KJ, Rosamond WD, & Mittleman MA (2010). Coffee and acute ischemic stroke onset: The Stroke Onset Study. Neurology PMID: 20881275