Sunday, August 29, 2010

How to improve your cognitive function

In an era of ever increasing lifespan, a recent study estimated that there would be 81.1 million people with dementia by 2040 (Ferri et. al., 2005). The prevalence and incidence of dementia has also been documented to increase with increasing age (Fratiglioni, Ronchi & Agüero-Torres, 1999).



Abraham Lincoln in his infinite wisdom, once said: “In the end, it's not the years in your life that count. It's the life in your years”. So what can we do to enhance our cognitive functions as we age?

The link between exercising and cognitive health is an area of intense research but some questions remains unanswered. What component of cognitive functioning does exercise improves and how much does the quantity of exercise affect any subsequent increase in cognitive functions? Masley, Roetzheim & Gualtieri (2009) provides some answers.

Participants were classified into 3 conditions for a 10 week intervention programme.
  • Control (0 – 2 days/week of aerobic activity)
  • Moderate (3 – 4 days/week of aerobic activity)
  • Intense (5 – 7 days/week of aerobic activity)
They were administered with a set of computerized battery tests that examined their performance on 5 domains – memory, psychomotor speed, information processing time, attention and cognitive flexibility. After a 10 week exercise programme intervention, they were required to complete the test again and their pre and post treatments scores were compared.

Results:

  • After controlling for demographic factors such as age, gender and education, only cognitive flexibility (a measure of executive function) improved significantly.
  • There was a positive relationship between amount of exercise and improvements in cognitive function. The more you exercise, the larger the increase in executive function.

So what are you waiting for? Go get yourself some aerobic exercise (preferably in a natural environment) because interaction with a natural environment as opposed to an urban environment has also been shown to improve cognitive functions. (Berman, Jonides  & Kaplan, 2008)

ResearchBlogging.org
Masley S, Roetzheim R, & Gualtieri T (2009). Aerobic exercise enhances cognitive flexibility. Journal of clinical psychology in medical settings, 16 (2), 186-93 PMID: 19330430

Berman, M., Jonides, J., & Kaplan, S. (2008). The Cognitive Benefits of Interacting With Nature Psychological Science, 19 (12), 1207-1212 DOI: 10.1111/j.1467-9280.2008.02225.x

Ferri, C., Prince, M., Brayne, C., Brodaty, H., Fratiglioni, L., Ganguli, M., Hall, K., Hasegawa, K., Hendrie, H., & Huang, Y. (2006). Global prevalence of dementia: a Delphi consensus study The Lancet, 366 (9503), 2112-2117 DOI: 10.1016/S0140-6736(05)67889-0

Fratiglioni, L., De Ronchi, D., & Ag??ero Torres, H. (1999). Worldwide Prevalence and Incidence of Dementia Drugs & Aging, 15 (5), 365-375 DOI: 10.2165/00002512-199915050-00004

Tuesday, August 17, 2010

Becoming a Better Person: The Good, the Bad, and the Past


When we think of ourselves as being morally good or morally bad, what goes on in our brains? What moral memories does our mind gather to affirm that we are one or the other, and how are these memories influenced by cognitive biases?

In some ways, we are already aware of some cognitive biases in the way we remember events. For example, we know of an "emotional bias" where emotional memories are remembered more vividly, are typically easier to retrieve and seem more familiar, even when the actual memories are not typically accurate. There also appears to be a"positivity bias" in that positive memories tend to be more vivid then negative ones and are less easily forgotten.


Not much research has been done on moral memories and given that moral memories are often emotional ones (cheating on a partner for instance, or helping someone and receiving their gratitude in turn), similar cognitive biases might exist. In this study, the authors hypothesize that we would remember ourselves doing good deeds more recently, a sort of "temporal bias".

The authors collected 700 autobiographical moral memories and characterized them on 3 categories of good versus bad. They also measured how long ago these events took place and collected data on possible contributing factors like gender, IQ, personality, etc. They then compared the mean age of the morally good memories to the morally bad memories and found that the morally good memories were always more recent.



What could drive these findings? The authors list 3 distinct and fascinating possibilities.

1) People actively reconstruct their memories to render their most recent acts, the acts to which one is most accountable, in a more positive light and relegate bad deeds to the distant past where one can come up with a host of reasons like "I was young" or "I didn't know better". This would be a real "temporal bias".

2) Perhaps bad decisions are more emotionally arousing and hence are remembered better (refer to "emotional bias" above) and their memories, older.

3) There is some real difference in the way people act when they are younger and when they older, so they remember their older self as being more morally good while their younger self as being morally bad. This would be a non-psychological explanation for the phenomena examined above.

While I think the study does indeed have several flaws that makes it hard to disentangle the possibilities, the idea it raises is quite exceptional. The way I interpret it is that, for the most part, we always strive to be better people, but we can never forget the wrongs that we have done. The solution that the brain seems to have evolved, if the authors are correct, is to relegate the ugly deeds to the past, and push the good to the present.

ResearchBlogging.orgEscobedo, J., & Adolphs, R. (2010). Becoming a better person: Temporal remoteness biases autobiographical memories for moral events. Emotion, 10 (4), 511-518 DOI: 10.1037/a0018723

Saturday, August 14, 2010

Cognitive Inferences and Optical Illusions

Ever wondered what allows us to be so perceptive about the world around us that it's almost taken for granted? Or why it is so difficult to create a robot with human-like perception, intelligence and understanding?

The discovery that the brain forms assumptions about the world in order to facilitate our lives has been one of the most illuminating insights from psychology and neuroscience.

Assumptions, or cognitive inferences, are what separates humans from robots. One very salient instance of this is our ability to see a man and his shadow against a wall, and not perceive that there is actually another physical object next to the man. Robots need to be programmed an infinite number of rules to overcome just this problem which our brain easily solves by utilizing assumptions that have been formed based on our experiences and through learning

One very interesting way of teasing out these assumptions is by means of optical illusions. Optical illusions fool us because they violate our assumptions about what we see. A really good one I'd recommend is this illusion by Edward H. Adelson.





What is special about this, you might ask? Well, Tile A and Tile B are objectively the same colour.
Look again. It might be hard to believe at first, but it really is!

And to prove it (I couldn't believe it myself initially), I did the following. I created a brownish-green oval, copied it so that there are exactly two same coloured ovals, and shifted them into the tiles.



Amazingly, the two ovals appear different accordingly.

To shortcut the process above, here's probably what's going on.



The bar in the middle is really a uniformly grey bar.

What's happening is that our mind cannot divorce the effect of shadows from our perception. As long as the picture shows the green cylinder casting a shadow, the 'shadow assumption' module of our brains gets activated and the things in relation to it will be affected. A robot should typically see Tiles A and B to be the same.

Our assumptions fill in the gaps so that our perception of the world becomes seamless and efficient (and it doesn't feel like we're constantly bombarded with stimuli).

ResearchBlogging.org
Adelson, E. (1993). Perceptual organization and the judgment of brightness Science, 262 (5142), 2042-2044 DOI: 10.1126/science.8266102

Adelson, E. (2001). On seeing stuff: The perception of materials by humans and machinesHuman Vision and Electronic Imaging VI, Bernice E. Rogowitz; Thrasyvoulos N. Pappas, Editors, pp.1-12

Saturday, August 7, 2010

What should you spend on to maximize your happiness?

When it comes to spending our money, we instinctively think that we will derive the most happiness by spending it on ourselves, regardless of whether it is to pay that pesky bill, or buy ourselves a nifty new gadget or that gorgeous handbag that we have been eyeing for ages. But is spending money on ourselves really the best way to boost our happiness, or is there something more to it? Dunn, Aknin & Norton (2008) provide some unexpected insights.

The researchers hypothesized that, compared to spending money on ourselves, spending money on others will actually make us happier. 632 Americans were asked to rate their happiness, indicate their annual income and also estimate how they spend their money in a month, which was subsequently categorized into Personal Spending & Prosocial Spending.

Results:

  • Personal Spending (Bills & expenses, Gifts for themselves) was not a significant predictor of happiness.
  • Prosocial Spending (Gifts for others, Donations to charity) was a significant predictor of happiness.
The authors proceeded to extend their study to investigate whether people who received a windfall would be happier if they had spent it on themselves or on others. The windfall here refers to a profit-sharing bonus for 16 employees in a company. They were asked to rate their happiness 1 month before (Time 1) getting the bonus and after 6-8 weeks (Time 2). Participants were then asked to estimate how they spent the bonus, which was also subsequently categorized into Personal Spending & Prosocial Spending.

Results:

  • Personal Spending (Bills & expenses, Rent or mortgage, Buying something for themselves) was not a significant predictor of happiness at Time 2.
  • Prosocial Spending (Buying something for someone else, Donating to charity, Other) was a significant predictor of happiness at Time 2.
  • They also found that how the participants spend the bonus was more important than the size of the bonus.
In order to establish a causal relation using an experimental methodology, the researchers gave participants either $5 or $20 and were instructed to either spend it on themselves (Personal Spending) or to spend it on others (Prosocial Spending).

Results:

  • Participants who were in the Prosocial Spending condition reported greater happiness than participants who were in the Personal Spending condition.
  • The size of the money ($5 or $20) did not have a significant effect on happiness.
So how can we make use of these findings to maximize our happiness by deciding on what we should spend on?

In sum:

  • Allocate some of our spending on others (Gifts, donations etc.).
  • The sum does not have to be big, even an amount of $5 when spent in a prosocial manner can result in significantly higher happiness levels.
  • We can make ourselves happier than a person with a bigger bonus by simply tweaking how we spend our cash.
ResearchBlogging.org
Dunn, E., Aknin, L., & Norton, M. (2008). Spending Money on Others Promotes Happiness Science, 319 (5870), 1687-1688 DOI: 10.1126/science.1150952

Saturday, July 24, 2010

How to maxmize your happiness from a vacation.

I am sure that most, if not all of us would agree that going on a vacation makes us happy. But are we really happier than people who are not going for a holiday? And if we are indeed happier, how long do these effects persist and how does the length of our vacation and amount of holiday stress impact our happiness levels? These are some of the questions that Nawijn, Marchand, Veenhoven & Vingerhoets (2010) attempt to answer.

Their main findings are listed below.
  1. Pre-trip happiness: Vacationers (n=974) displayed significantly higher degrees of happiness than non-vacationers (n-556)
  2. Post-trip happiness: Vacationers were generally not significantly happier than non-vacationers. Only vacationers who rated their holidays as very relaxed (as opposed to relaxed, neutral, stressful or very stressful) had significantly higher degrees of happiness for the first 2 weeks after the vacation.
  3. Length of vacation was not associated with post-trip happiness.
*Note: The vacation began between week 27 and week 35.

So what do these findings tell us about how we should plan our vacations?

For starters, the planning and anticipation of the upcoming vacation makes us much happier folks than those who are not looking forward to a vacation.

The second finding, in line with the set point theory of happiness, indicates that once we are back from a vacation, our happiness returns rapidly back to baseline levels. Only the 'very relaxed' vacationers get an additional 2 weeks boost of happiness. So if you want that extended endorphins kick, make sure that you are really relaxed during the vacation.

The last finding, together with the first two findings, suggests that in order to derive the most happiness out of your vacation, it would be better to take multiple short trips rather than a long trip. Since the length of the vacation is not associated with happiness, you'll get the most bang for your buck by enjoying the pre-trip happiness generated from planning and anticipating multiple trips.

In sum:
  1. Enjoy the planning process
  2. Do your best to make your trip very relaxing (a trip that is just 'relaxed' doesn't quite cut it)
  3. Multiple short trips are better than one long trip
ResearchBlogging.org
Nawijn, J., Marchand, M., Veenhoven, R., & Vingerhoets, A. (2010). Vacationers Happier, but Most not Happier After a Holiday Applied Research in Quality of Life, 5 (1), 35-47 DOI: 10.1007/s11482-009-9091-9

Friday, July 16, 2010

Boost your Guitar Hero skills 101 - SLEEP! Really?

We have been told that feeling well-rested while studying and reviewing your work just before bedtime enhances your memory for what you have studied. But when it comes to the role of sleep in motor memory, the answer is less clear. A recent research abstract presented at the 24th annual meeting of the Associated Professional Sleep Societies LLC by Dr Kevin Peters from Trent University suggests that sleep enhances our performance in complex motor learning tasks, as measured by an larger increase in accuracy levels obtained in playing guitar hero in the sleep condition compared to the wake condition.

However, an earlier paper by Cai & Rickard (2009) suggests that after controlling for circadian (time of day) and homeostatic (time since sleep) confounds, participants in the sleep conditions did not display any benefits in a motor sequence task.

The participants in their research were categorized into 3 conditions - a wake group, a 1 night sleep post-training group and a 2 night sleep post-training group. Participants were tasked to tap a number sequence, 4-1-3-2-4 repeatedly and reaction times (RTs) were measured. All participants trained at about 9.30am and were tested on 5.30pm on the day itself or on Day 2 and Day 3 depending on which conditions they were in.

Comparing difference scores of their RTs for the 3 different groups revealed no significant differences between them. If sleeping does indeed improve motor memory, we would expect a significant reduction in RTs for the sleep groups compared to the wake group. Therefore, it appears that after controlling for circadian and homeostatic factors, sleeping after training does not improve motor sequence performance.



Unfortunately, I do not have access to the exact methodology and results of Peter's study to verify if the concerns about the relevant confounds raised by Cai & Rickard (2009) are adequately addressed. Therefore, as far as I'm concerned, the jury is still out on the specific benefits (if any) conferred to motor memory by sleep. But I must say that Peter's design holds much promise (he certainly won't have any trouble finding willing and good subjects).

Well, regardless of whether sleeping helps you perfect that golf swing or ramp up your skill level on guitar hero, it’s still a good idea to get a good night's rest to ward off the negative effects associated with sleep deprivation in other domains of our lives. Afterall, according to a study by Falleti, Maruff, Collie, Darby & McStephen (2003), driving after being awake for 24hrs is like driving with a blood alcohol concentration of 0.05%. Not quite enough to get you arrested but probably more than enough to make you think twice about pulling that all-nighter.


ResearchBlogging.org
Cai, D., & Rickard, T. (2009). Reconsidering the role of sleep for motor memory. Behavioral Neuroscience, 123 (6), 1153-1157 DOI: 10.1037/a0017672

Falleti MG, Maruff P, Collie A, Darby DG, & McStephen M (2003). Qualitative similarities in cognitive impairment associated with 24 h of sustained wakefulness and a blood alcohol concentration of 0.05%. Journal of sleep research, 12 (4), 265-74 PMID: 14633237

Wednesday, July 7, 2010

Is Money the Arbitrator of the Fine Line Between Self-Interest and Community Spirit?

Does money serve as a great incentive and motivator or does it serve to undermine relationships? At the heart of the debate for society, this is akin to the perennial capitalism vis-à-vis communism conflict. And perhaps the truth is that they are both right.

Vohs, Mead & Goode's (2006) nine experimental studies, which culminated into an illuminating piece of work titled The Psychological Consequences of Money, found that both characteristics of money - a great incentive or an underminer of relationships - emerge from the same underlying process: money makes people feel self-sufficient and therefore behave accordingly.

In Experiment 1, participants were assigned randomly to three conditions. In two conditions, participants were reminded of money (Play Money and Money Prime) while in the control condition, participants were not reminded of money. In each condition, participants were instructed to unscramble jumbled up words to form sensible sentences, and therein lay the prime. In the Money Prime condition, the scrambled text contained concepts of money. In the Play Money and Control conditions, the scrambled texts were neutral, but participants in the Play Money condition were exposed to Monopoly money in their peripheral visual field.

Next, participants were given a challenging but solvable problem to work on. As the experimenter left the room, he offered that he was able to provide assistance if the participant wanted. How long the participants persisted before asking for help became the dependent variable to be measured.

It was observed that participants who were reminded of money (both Play Money and Money Prime) worked on the problem longer than control participants before requesting for help. The difference between the two money conditions (Play Money vs Money Prime) was insignificant.





Experiment 2 was a modification of Experiment 1 such that the constructs being measured were an abundance of money (High Money) against restricted amount of money (Low Money). Participants then had to read aloud an essay in front of a video camera. The video camera was used in place of an experimenter so as to remove the potential confound that might result from status differences between the experimenter and the student.

Participants in the High Money condition read about growing up with abundant financial resources, while participants in the Low Money condition read about growing up with meagre financial resources. Participants were then, like in Experiment 1, unknowingly tested on how long they would take to solve an unsolvable puzzle before requesting help.

Once more, participants in the High Money condition worked significantly longer than participants in the Low Money condition before asking for help. This experiment also confirmed that the effects of money did not depend on relative status differences between the participant and the experimenter/helper.



Given the findings thus far and the overall hypothesis, the authors predicted that people who value self-sufficiency would be less helpful than others because they will tend to expect others to be self-sufficient as well. The authors do not elaborate on this aspect, but a few reasons why this is a reasonable stipulation include:

  • the tendency for people to project their own personalities onto others in order to form more efficient judgments and anticipate behaviours of others,

  • the fact that schemas associated with ourselves are more accessible and thus more easily activated, and

  • the possibility that we have evolved psychological mechanisms to assume that when we are rich, the environment allows for it because we are in a resource-rich area, and we are more likely to be dealing with other rich people residing in our local environment.

Thus, in Experiments 3, 4 and 6 (all involving different sets of randomly selected subjects), the authors sought to test whether participants primed with money would be less helpful relative to control participants.

Using the word descrambling methodology from Experiment 1 to manipulate the priming for both money and neutral conditions, the DV - willingness to provide assistance - was then measured. Experiment 3 tested participants on their tendency to help out in a future task (willingness to help code the data sheets of the current experiment), while Experiment 4 tested their helpfulness on an immediate helping situation (willingness to help a fellow 'latecomer' participant, who was really a confederate, figure out the experiment's instructions). Experiment 6 assessed how willing participants were in donating their participation payment to a university student fund.

It was found that participants in the money condition volunteered to help code fewer data sheets (Experiment 3), spent half as much time providing help to the latecomer on the instructions (Experiment 4) and donated less money (Experiment 6) than participants in the control condition.

In Experiment 5, participants were made to play Monopoly with a confederate. After a few rounds, the game was cleared except for differing amounts of play money. Participants in the High Money condition were left with $4000 (participants will be aware that this is a large sum of Monopoly money having been sensitized to the game), while participants in the Low Money condition were left with $200. Control condition participants were left with no money. For High Money and Low Money participants, the money was kept in conscious sight for the second step of the experiment. At this step, High Money participants were asked to imagine a wealthy future while Low Money participants were asked to imagine a financially insecure future. Control participants were asked to imagine their plans for the next day.

This was followed by a staged accident where a new confederate, who was both blind to the condition the participants were in and carrying a lot of things, walks across the laboratory and drops his pencils (27 in total) in front of the participant. The number of pencils picked up by the participant became the measure of helpfulness.

Participants in the High Money condition helped gather significantly fewer pencils than participants in the Low Money and Control conditions. Helpfulness did not differ between the Low Money group and the Control group.

To ascertain self-sufficiency as the construct that is really being tested, the final three experiments tested the effects of money on social intimacy, desire to engage in leisure activities alone and preference to work alone.

In Experiment 7 involving screensavers, participants were randomly assigned to either the Money condition, Fish condition or No Screensaver condition. All participants were made to fill in questionnaires while sitting in front of an idle computer screen. After a few minutes, one of three screensaver types would appear - one depicting various denominations of currency floating underwater, one with fishes swimming underwater, and one with just a blank screen.

After some degree of exposure to the screensaver, participants were told they would get acquainted with another participant in the same experiment, but the experimenter would require some assistance to arrange the chairs for the session. Participants primed with the Money screensaver placed the two chairs for him or herself and the potential acquaintant farther apart compared to participants in both the Fish group and the No Screensaver group.

Participants primed with money appeared to place more social distance between themselves and others.

Experiment 8 tested whether money-primed participants would prefer being alone even when choosing leisure activities that are potentially of a social nature. The priming manipulation was similar to Experiment 7, except that instead of screensavers being used, participants were now facing posters. The Money condition participants faced a poster showing various denominations of currency, while the two control groups faced a poster showing either a seascape or a flower garden.

Participants were next given a nine-item questionnaire that asked them to choose between two leisure activities per question. Within each item, one option was an experience only one person could enjoy while the other option was for two or more people. Money-primed participants chose more individually-focused leisure activities than participants from the control groups.

Money primes thus appear to lead people to become less social.

Experiment 9 provided a more rigorous test of the self-sufficiency hypothesis by directly assessing social preferences. Participants were put through the screensaver primes from Experiment 7 before being asked whether they preferred to work alone or with others. Once more, participants desired to work less with a peer when exposed to money primes.

The nine experiments provide support for the proposed argument that money activates psychological mechanisms that bring about a state of self-sufficiency. It might even appear somewhat surprising that such minor tweaks in environmental and social conditions towards a heightened sensation of financial resources might induce a person to be more independent and socially insensitive.

As the authors sum up well, "The self-sufficient pattern helps explain why people view money as both the greatest good and evil. As countries and cultures developed, money may have allowed people to acquire goods and services that enabled the pursuit of cherished goals, which in turn diminished reliance on friends and family. In this way, money enhanced individualism but diminished communal motivations, an effect that is still apparent in people’s responses to money today."

So ultimately, perhaps whether you believe money is inherently good or evil might begin with what inclinations you have towards social dynamics and morals to begin with.

ResearchBlogging.org
Vohs, K., Mead, N., & Goode, M. (2006). The Psychological Consequences of Money Science, 314 (5802), 1154-1156 DOI: 10.1126/science.1132491