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.

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

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.


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

Link between Sexual Motivation State and Dopamine Release in the mPOA?

Is an increase in dopamine release in the medial preoptic area (mPOA) specifically related to male physical arousal and sexual behavior or does it have a bigger role in sexual motivation?

Kleitz-Nelson, Dominguez, Cornil & Ball (2010) investigated this question by using the Japanese quail (Coturnix japonica). The male quail does not an have an intromittent organ and therefore does not require an erection to successfully copulate. The researchers collected and measured the dopamine content from extracellular samples from the adult male quails’ mPOA every six minutes before, during and after exposure to a female quail.

What they found was that for male quails that copulated, their levels of extracellular dopamine increased dramatically past baseline levels (BL1-3) when the female quail was introduced (F1-F6) and decreased after the female quail was removed (POST1-POST6). Non-copulators did not exhibit an increase in extracellular dopamine levels.

In addition, for copulators, the researchers did not find any changes in extracellular dopamine levels between sampling periods during which the quails either engaged in the actual mating behavior or not. That is to say, during the sampling period, regardless of whether the male quail was engaging in coitus or not, their levels of extracellular dopamine levels showed increased levels as long as they are in the presence of the female.

The authors thus concluded that the rise in extracellular dopamine in the mPOA is not only involved in erection and ejaculation, as the copulators had high levels of extracellular dopamine regardless of whether they were actually engaging in mating behavior at that moment. And given that the quails do not require an erection for copulation to occur, the evidence suggests strongly that extracellular dopamine in the mPOA is specifically associated with sexual motivation and not just physical arousal.


Kleitz-Nelson, H., Dominguez, J., Cornil, C., & Ball, G. (2010). Is sexual motivational state linked to dopamine release in the medial preoptic area? Behavioral Neuroscience, 124 (2), 300-304 DOI: 10.1037/a0018767

Sorry honey, I just had to buy that dress! - When cognitive overload undermines our self-regulatory ability.

Counterintuitively, people who exercise self control in some way, such as dieting or trying not to look at or think about something, might end up buying things more impulsively instead if given the opportunity.

Vohs & Faber (2007) explain in their study, Spent Resources: Self-Regulatory Resource Availability Affects Impulse Buying, that opportunities for impulse purchasing have increased with the proliferation of ATMs, shopping on the Internet, and shop-at-home television programs. Depletion of cognitive self-regulatory resources coupled with ever-increasing avenues for impulse buying might just be the answer.

In one experiment, 35 undergraduate participants were made to watch a video of a woman talking on the pretext that they were going to judge her personality later. To suppress one group's attentional resources, irrelevant words were flashed at the bottom of the screen and participants were told to ignore the irrelevant words and focus instead on the woman. Another group was given no such instruction to divert their attention away from the words, and thus served as the control group. After the video, participants were told that they were taking part in a marketing study to determine the prices that students would pay for various products.

It was found that participants who had their attention manipulated assigned significantly higher prices to the products than participants in the control group.

In the second experiment, 73 undergraduates participated by first completing the trait Buying Impulsiveness Scale (BIS), a scale developed by Rook and Fisher (1995) which measures generalized urges to spend impulsively. This was followed by a thought suppression exercise where participants were induced with the thought of a 'white bear', an interesting experimental technique developed by Wegner in 1989 that has been proven to drain considerable cognitive resources. Participants were told to write down their thoughts for the next few minutes. Participants in the Thought Suppression condition were told that they should try and avoid thinking of a white bear and if they did think of a white bear, they should place a check mark on their paper and then resume recording their thoughts. Participants in the No Suppression condition could think of anything they wanted, including white bears.

After this, participants were told that they were going to be involved in a study about introducing new products at the university bookstore. Participants would be given $10 for their participation in the study, after which they could either leave with the money, or they could make a purchase with the items that were available as part of the bookstore's product study.

It was found that spontaneous buying behaviour is once more predicted by mental resource depletion, as students who did not have to suppress their thoughts were more likely to keep the $10 and leave. Additionally, an interaction effect between dispositional buying impulsiveness (as determined by the BIS) and the self-regulatory resource condition was found. As the authors assert, "Among people who are prone to buying impulsively, temporary lapses in self-control ability signal a strong possibility that impulsive, unplanned, and perhaps unwanted spending may occur."

In the last experiment of the study, 40 undergraduate subjects took a variant of the second experiment to determine that the results were not confounded by other cognitive or affective traits, such as the desirability of the items being purchased.

This study extends the research on impulse buying, which has come a long way since the 1980s where people were simply labeled as either impulsive or nonimpulsive purchasers, effectively indicating that there is an interaction between both dispositional and environmental influences that determines impulse-buying. In other words, personality and social factors both play a part. The authors conclude: "Self-regulatory resource availability would be an important element in determining when and why people engage in impulsive spending." Without enough self-regulatory resources, people will be less able to overcome urges and substitute desirable behaviours with undesired ones. Thus, temporary reductions in the capacity to self-regulate leads to stronger impulsive buying tendencies.

From this research, it appears that people in modern contexts do not stand confidently in the ability to control their temptations, as contemporary city-living inundates our senses with a twin barrage of cognitive overload as well as opportunities to spend.


Vohs, K., & Faber, R. (2007). Spent Resources: Self‐Regulatory Resource Availability Affects Impulse Buying Journal of Consumer Research, 33 (4), 537-547 DOI: 10.1086/510228

Sorry, what's your name again? - How stress impairs our social memory.

Ever felt that someone hasn't been paying attention to what you were saying in previous conversations because he/she forgets biographic information about you that you had mentioned countless times? Well, it turns out that it might just be that they're stressed out by something else.

In their paper, Stress Impairs Retrieval of Socially Relevant Information, Merz, Wolf & Hennig (2010) investigated the hypothesis that parts of our social memory (memory about names, birth dates, parts of other people’s life) fail because of stress.

15 women and 14 men were recruited to take part in an experiment whereby they were randomized into either the Stress or Control conditions. All participants started the experiment by memorizing two biographical notes (one from each gender) which includes photos, home towns and parts of their life stories.

Stress was then induced on the participants in the stress condition by instructing them that they would have to give a public speech 10 minutes later. Cortisol levels in saliva samples collected during 5 different time intervals during the whole experiment were used to quantify their stress levels.

All participants were then tested on the biographical notes that they learnt at the beginning of the experiment. Participants were tested on recognition (selecting the correct answer out of 5 choices), correction (marking the incorrect answer out of 5 choices) and reproduction (answering semi-open ended questions). Global Memory indicates the average of the three tests.

The authors found that participants in the stress condition had significantly lower recognition, reproduction and global memory scores than participants in the control condition.

Mean cortisol response during memory retrieval of responders (participants who show stress induced cortisol increase) also had a significant negative correlation with the recognition task and global memory score.

The authors conclude that acute stress reduces our ability to retrieve socially relevant information and that there was an association between these stress-induced retrieval deficiencies and cortisol response to the stressor.

So, cut that person some slack when he/she forgets something about you; it might just be the cortisol, or even the pressure you're inducing on the person to remember stuff about you!


Merz, C., Wolf, O., & Hennig, J. (2010). Stress impairs retrieval of socially relevant information. Behavioral Neuroscience, 124 (2), 288-293 DOI: 10.1037/a0018942