In the early 1980s, psychologist Benjamin Libet conducted a relatively simple experiment that critically shaped the way we think about free-will. Participants sat facing a clock, keeping a finger on a button, and were instructed to lift the finger whenever they pleased, remembering the clock time corresponding to the time when they decided to move the finger. All the while, EEG was being recorded. Libet found that 300-500 msec before participants moved (and about 150 msec before reporting that they decided to move), that a strong negative signal was found in the EEG waveforms. If the brain "knows" you are going to move before you do, do you really have conscious control over your own behavior?
The Libet experiment has been replicated, if not uncontroversial among philosophers. However, a new paper in Psychological Science questions whether the readiness potential is an artifact of observing a moving clock.
In the new study, Jeff Miller and colleagues presented participants with two decision-making conditions: a clock condition, similar to that of Libet, and a condition without the clock. If the time between the decision and the movement is constant, then one can look at the EEG from the time to move, with or without the clock. The authors found that participants in the clock condition showed the readiness potential, but the participants in the no-clock condition did not, suggesting that the act of monitoring the clock modulated the EEG signal, not the preparation for making a decision.
I think that this study is innovative as we need new methods to study the time course of decision making. I do think it asks more questions than it answers, though. For example, there are differences between the clock and no-clock groups that go beyond the presence of a clock: being asked to keep a time in mind provides a load to working memory that the no-clock participants did not have.
Is it time to give up on Libet? I'm not so sure. Is it time to reconsider with new methods? Absolutely!
Miller J, Shepherdson P, & Trevena J (2010). Effects of Clock Monitoring on Electroencephalographic Activity: Is Unconscious Movement Initiation an Artifact of the Clock? Psychological science : a journal of the American Psychological Society / APS PMID: 21123855
Monday, January 3, 2011
Sunday, January 2, 2011
Sunday Soundbites: Happy New Year!
Is peer review better than chance? A new study says "maybe not".
Who is more likely to be prescribed a cognitive enhancer, me or my father? A new study in PLoS says it's Dad.
Confused about what is and is not a mental disorder according to the DSM-V? So are most experts, says NPR.
This is the smartest thing I've read about "neurobabble" all week.
The ever-excellent Dan Ariely has a post about money and cognitive heuristics.
Bora Zivkovic has an excellent article on the history of scientific discourse, and the links between scientific and journalistic writing.
Can Google's new Ngram toy show which science is fad and which is legit? Big Think says yes. I'm not so sure, but they have cool graphs.
People who believe in free will have better job performance, reviewed by Barking up the Wrong Tree.
Who is more likely to be prescribed a cognitive enhancer, me or my father? A new study in PLoS says it's Dad.
Confused about what is and is not a mental disorder according to the DSM-V? So are most experts, says NPR.
This is the smartest thing I've read about "neurobabble" all week.
The ever-excellent Dan Ariely has a post about money and cognitive heuristics.
Bora Zivkovic has an excellent article on the history of scientific discourse, and the links between scientific and journalistic writing.
Can Google's new Ngram toy show which science is fad and which is legit? Big Think says yes. I'm not so sure, but they have cool graphs.
People who believe in free will have better job performance, reviewed by Barking up the Wrong Tree.
Wednesday, December 29, 2010
Why brain-based lie detection is not ready for "prime time"
We are in a new and interesting legal world. Although to date, no US court cases have used brain-based lie detection techniques as evidence, several cases have sought such evidence and settled out of court. fMRI is the most frequent type of brain-based lie detection technology, with two companies, Cephos and No Lie MRI providing this service in the legal domain. There have also been attempts made to use EEG for deception detection. Notably, such a technique was used in part to prosecute a young woman for murder in India in 2008.
I am far from the first to point out that this technology is highly exploratory and not accurate enough to be used in the court of law. My goal here is to outline a good number of the reasons this is the case.
9. We do not know how accurate these techniques are. Although the two aforementioned companies boast lie detection accuracy rates of 90%+, these cannot be independently verified by an independent lab as the methods used by these companies are trade secrets. For example, there are few peer-reviewed studies of the putative EEG-based marker of deception, the P300, and most come from the lab that is commercially involved with a company trying to sell the technique as a product. Interestingly, an independent lab studying the effect of countermeasures on the technique found an 82% hit rate in controls (not the 99% accuracy claimed by the company), and this was reduced to 18% when countermeasures were used!
8. In the academic literature, where we do have access to methodology, we are limited to testing typical research participants: undergraduate psychology majors (although see this). For a lie detection method to be valid, it would need to be shown as accurate in a wide variety of populations, varying in age, education, drug use, etc. This population is not likely to be skilled in deception as a career criminal might, and it has been shown that the more often one lies, the easier it is to lie. Most fMRI-based lie detection techniques are based on the assumption that lying is hard to do, and thus requires the brain to use more energy. If frequent lying makes lying easy, then it could be the case that practiced liars don't have this pattern of brain activity.
Although a fair amount has been made lately about WEIRD subjects, participants in these studies are actually beyond WEIRD: they are almost exclusively right handed, and predominantly male.
7. Along this same line, the "lies" that are told in these studies rarely have an impact on the lives of the student participants. Occasionally, an extra reward is given if the participant is able to "trick" the system, but in the real world, with reputations and civil liberties at stake, one might imagine that one might do a better job at tricking the scanner. However, being instructed to lie about a low-stakes laboratory situation is not the same as the high-stress situations where this technology would be used in real-life. Occasionally, a study will try to ameliorate this situation by using a mock crime (such as a theft) as the deceptive stimuli. However, these are also of limited use as participants know that the situation is contrived.
6. Like traditional polygraph tests, it is possible to fool brain-based lie detection systems with countermeasures. Indeed, in an article in press at NeuroImage, Ganis and colleagues found that deliberate countermeasures on the part of their participants dropped deception detection from 100% to 30%. Most studies of fMRI lie detection have found more brain activation for lies than truth, suggesting that it is more difficult for participants to lie. However, is this still the case with well-rehearsed lies? What about subjects performing mental arithmetic during truth to fool the scanner?
5. A general lack of consistency in the findings in the academic literature. To date, there are ~25 published, peer-reviewed studies of deception and fMRI. Of these studies there are at least as many brain areas implicated in deception, including the anterior prefrontal area, ventromedial prefrontal area, dorsolateral prefrontal area, parahippocampal areas, anterior cingulate, left posterior cingulate, temporal and subcortical caudate, right precuneous, left cerebellum, insula, putamen, caudate, thalamus, and various regions of temporal cortex! Of course, we know better than to believe that there is some dedicated "lying region" of the brain, and given the diversity of deception tasks (everything from "lie about this playing card" to "lie about things you typically do during the day"), the diversity of regions is not surprising. However, the lack of replication is a cause for concern, particularly when we are applying science to issues of civil liberties.
4. An additional issue surrounds the fact that many of these studies are not properly balanced. In other words, participants are instructed to lie more or less often than they are instructed to tell the truth.
3. There is a large difference between group averages and finding deception within an individual. Knowing that on average, brain region X is significantly more active in a group of subjects during deception than during truth does not tell you than for subject 2 on trial 9 than deception was likely to occur due to the differences in activation. Of course, some studies are trying to study this level of analysis, but right now they are the majority.
2. Some things that we think that are not true are not necessarily lies. Most of us believe we are above-average drivers, and smarter and more attractive than most even when these beliefs are not true. Memories, even so-called "flash-bulb" memories are not fool proof.
1. Are all lies equivalent to the brain? Are lies about knowledge of a crime the same in the brain as white lies such as "no, honey those pants don't make you look fat" or lies of omission or self-deceiving lies?
I am far from the first to point out that this technology is highly exploratory and not accurate enough to be used in the court of law. My goal here is to outline a good number of the reasons this is the case.
9. We do not know how accurate these techniques are. Although the two aforementioned companies boast lie detection accuracy rates of 90%+, these cannot be independently verified by an independent lab as the methods used by these companies are trade secrets. For example, there are few peer-reviewed studies of the putative EEG-based marker of deception, the P300, and most come from the lab that is commercially involved with a company trying to sell the technique as a product. Interestingly, an independent lab studying the effect of countermeasures on the technique found an 82% hit rate in controls (not the 99% accuracy claimed by the company), and this was reduced to 18% when countermeasures were used!
8. In the academic literature, where we do have access to methodology, we are limited to testing typical research participants: undergraduate psychology majors (although see this). For a lie detection method to be valid, it would need to be shown as accurate in a wide variety of populations, varying in age, education, drug use, etc. This population is not likely to be skilled in deception as a career criminal might, and it has been shown that the more often one lies, the easier it is to lie. Most fMRI-based lie detection techniques are based on the assumption that lying is hard to do, and thus requires the brain to use more energy. If frequent lying makes lying easy, then it could be the case that practiced liars don't have this pattern of brain activity.
Although a fair amount has been made lately about WEIRD subjects, participants in these studies are actually beyond WEIRD: they are almost exclusively right handed, and predominantly male.
7. Along this same line, the "lies" that are told in these studies rarely have an impact on the lives of the student participants. Occasionally, an extra reward is given if the participant is able to "trick" the system, but in the real world, with reputations and civil liberties at stake, one might imagine that one might do a better job at tricking the scanner. However, being instructed to lie about a low-stakes laboratory situation is not the same as the high-stress situations where this technology would be used in real-life. Occasionally, a study will try to ameliorate this situation by using a mock crime (such as a theft) as the deceptive stimuli. However, these are also of limited use as participants know that the situation is contrived.
6. Like traditional polygraph tests, it is possible to fool brain-based lie detection systems with countermeasures. Indeed, in an article in press at NeuroImage, Ganis and colleagues found that deliberate countermeasures on the part of their participants dropped deception detection from 100% to 30%. Most studies of fMRI lie detection have found more brain activation for lies than truth, suggesting that it is more difficult for participants to lie. However, is this still the case with well-rehearsed lies? What about subjects performing mental arithmetic during truth to fool the scanner?
5. A general lack of consistency in the findings in the academic literature. To date, there are ~25 published, peer-reviewed studies of deception and fMRI. Of these studies there are at least as many brain areas implicated in deception, including the anterior prefrontal area, ventromedial prefrontal area, dorsolateral prefrontal area, parahippocampal areas, anterior cingulate, left posterior cingulate, temporal and subcortical caudate, right precuneous, left cerebellum, insula, putamen, caudate, thalamus, and various regions of temporal cortex! Of course, we know better than to believe that there is some dedicated "lying region" of the brain, and given the diversity of deception tasks (everything from "lie about this playing card" to "lie about things you typically do during the day"), the diversity of regions is not surprising. However, the lack of replication is a cause for concern, particularly when we are applying science to issues of civil liberties.
4. An additional issue surrounds the fact that many of these studies are not properly balanced. In other words, participants are instructed to lie more or less often than they are instructed to tell the truth.
3. There is a large difference between group averages and finding deception within an individual. Knowing that on average, brain region X is significantly more active in a group of subjects during deception than during truth does not tell you than for subject 2 on trial 9 than deception was likely to occur due to the differences in activation. Of course, some studies are trying to study this level of analysis, but right now they are the majority.
2. Some things that we think that are not true are not necessarily lies. Most of us believe we are above-average drivers, and smarter and more attractive than most even when these beliefs are not true. Memories, even so-called "flash-bulb" memories are not fool proof.
1. Are all lies equivalent to the brain? Are lies about knowledge of a crime the same in the brain as white lies such as "no, honey those pants don't make you look fat" or lies of omission or self-deceiving lies?
Sunday, December 26, 2010
My picks for the top studies of 2010
Presented in no particular order, here are the ten studies of 2010 that I found the most interesting. Enjoy!
1. A Wandering Mind is an Unhappy Mind
I wrote about this study here. Authors used an iPhone app to obtain "what are you doing?", "what are you thinking about?" and "how happy are you right now?" data. It turns out that we are thinking about something other than what we are doing about half of the time, and these are the times we are least happy.
2. Electrical Enhancement of Mathematical Ability.
I wrote about it here. The authors used transcranial direct-current stimulation as participants were learning an novel digit vocabulary. The stimulation (if done in the proper direction) facilitated this type of learning.
3. Ego Depletion only Happens if you Believe it will Happen.
I wrote about it here. Ego depletion is the idea that self-control is like a muscle, and if you use too much of it, you need to rest it like a muscle. The authors show here that people who believed in ego depletion had depleted continuous self-control, whereas people who believed that self-control was not a limited resource did not. Critically, giving people one of the two beliefs also changed behavior in the predicted direction.
4. Habit Formation in the Real World.
Have you heard that it takes 28 days to form a new habit? This is a very common notion, but is it true? The authors found that it can take up to 60 days for people to report a new behavior feeling automatic.
5. Vollenweider's Review of Psychadelic Drugs
Everything you ever wanted to know about psychedelics, but were afraid to ask. Good review of neurobiology of these drugs and their potential therapeutic uses in depression, OCD, anxiety, etc.
6. Eye Position Predicts what Number you have in Mind
When asked to generate "random" numbers, people have a hard time being truly random. In this study, people were asked to generate random numbers while their eye movements were monitored. It was found that the number a person generated could be predicted from the position of the eyes: in particular, that eyes in the lower left part of the visual field predicted small numbers and eyes in the upper right predicted large numbers.
7. Willful Modulation of Brain Activity in Disorders of Consciousness
Until this paper, there had been limited reports of patients in minimally conscious states able to perform mental imagery tasks as measured with fMRI. However, we also know that diagnosis of these states is prone to errors. How common is it for minimally conscious patients to be able to follow mental directions? 54 patients were tested, and it was found that only 5 could perform the tasks.
8. Putting Brain Training to the Test
Making software to "train your brain" into being smarter, more attentive, and less forgetful is a lucrative industry, but there was little evidence for or against this kind of training leading to cognitive enhancement. This massive study used over 11,000 participants and found that although participants got better at the tasks in the games, no improvement was found in non-trained real-world tasks. Save your money, folks.
9. Outcome Reporting Among Drug Trials
All clinical trials need to be registered through the NIH at clinicaltrials.gov. This policy was designed to prevent Big Pharma from running near-infinite numbers of trials on a drug, then only reporting ones with positive results. This study examines differences between studies funded by industry, by government and by private organizations. Industry-funded trials had 85% positive results, while government-funded trials had 50% positive results. Humph.
10. Prediction of Individual Brain Maturity
Human brains mature rather late and at different rates. The issue of brain maturity has been key to policy decisions about how to punish adolescent criminals and how to insure adolescent drivers. This study uses fMRI to show how mature an individual brain is.
Killingsworth MA, & Gilbert DT (2010). A wandering mind is an unhappy mind. Science (New York, N.Y.), 330 (6006) PMID: 21071660
Cohen Kadosh R, Soskic S, Iuculano T, Kanai R, & Walsh V (2010). Modulating neuronal activity produces specific and long-lasting changes in numerical competence. Current biology : CB, 20 (22), 2016-20 PMID: 21055945
Job V, Dweck CS, & Walton GM (2010). Ego depletion--is it all in your head?: implicit theories about willpower affect self-regulation. Psychological science : a journal of the American Psychological Society / APS, 21 (11), 1686-93 PMID: 20876879
Vollenweider FX, & Kometer M (2010). The neurobiology of psychedelic drugs: implications for the treatment of mood disorders. Nature reviews. Neuroscience, 11 (9), 642-51 PMID: 20717121
Loetscher, T., Bockisch, C., Nicholls, M., & Brugger, P. (2010). Eye position predicts what number you have in mind Current Biology, 20 (6) DOI: 10.1016/j.cub.2010.01.015
Monti, M., Vanhaudenhuyse, A., Coleman, M., Boly, M., Pickard, J., Tshibanda, L., Owen, A., & Laureys, S. (2010). Willful Modulation of Brain Activity in Disorders of Consciousness New England Journal of Medicine, 362 (7), 579-589 DOI: 10.1056/NEJMoa0905370
Owen, A., Hampshire, A., Grahn, J., Stenton, R., Dajani, S., Burns, A., Howard, R., & Ballard, C. (2010). Putting brain training to the test Nature, 465 (7299), 775-778 DOI: 10.1038/nature09042
Bourgeois FT, Murthy S, & Mandl KD (2010). Outcome reporting among drug trials registered in ClinicalTrials.gov. Annals of internal medicine, 153 (3), 158-66 PMID: 20679560
Dosenbach NU, Nardos B, Cohen AL, Fair DA, Power JD, Church JA, Nelson SM, Wig GS, Vogel AC, Lessov-Schlaggar CN, Barnes KA, Dubis JW, Feczko E, Coalson RS, Pruett JR Jr, Barch DM, Petersen SE, & Schlaggar BL (2010). Prediction of individual brain maturity using fMRI. Science (New York, N.Y.), 329 (5997), 1358-61 PMID: 20829489
1. A Wandering Mind is an Unhappy Mind
I wrote about this study here. Authors used an iPhone app to obtain "what are you doing?", "what are you thinking about?" and "how happy are you right now?" data. It turns out that we are thinking about something other than what we are doing about half of the time, and these are the times we are least happy.
2. Electrical Enhancement of Mathematical Ability.
I wrote about it here. The authors used transcranial direct-current stimulation as participants were learning an novel digit vocabulary. The stimulation (if done in the proper direction) facilitated this type of learning.
3. Ego Depletion only Happens if you Believe it will Happen.
I wrote about it here. Ego depletion is the idea that self-control is like a muscle, and if you use too much of it, you need to rest it like a muscle. The authors show here that people who believed in ego depletion had depleted continuous self-control, whereas people who believed that self-control was not a limited resource did not. Critically, giving people one of the two beliefs also changed behavior in the predicted direction.
4. Habit Formation in the Real World.
Have you heard that it takes 28 days to form a new habit? This is a very common notion, but is it true? The authors found that it can take up to 60 days for people to report a new behavior feeling automatic.
5. Vollenweider's Review of Psychadelic Drugs
Everything you ever wanted to know about psychedelics, but were afraid to ask. Good review of neurobiology of these drugs and their potential therapeutic uses in depression, OCD, anxiety, etc.
6. Eye Position Predicts what Number you have in Mind
When asked to generate "random" numbers, people have a hard time being truly random. In this study, people were asked to generate random numbers while their eye movements were monitored. It was found that the number a person generated could be predicted from the position of the eyes: in particular, that eyes in the lower left part of the visual field predicted small numbers and eyes in the upper right predicted large numbers.
7. Willful Modulation of Brain Activity in Disorders of Consciousness
Until this paper, there had been limited reports of patients in minimally conscious states able to perform mental imagery tasks as measured with fMRI. However, we also know that diagnosis of these states is prone to errors. How common is it for minimally conscious patients to be able to follow mental directions? 54 patients were tested, and it was found that only 5 could perform the tasks.
8. Putting Brain Training to the Test
Making software to "train your brain" into being smarter, more attentive, and less forgetful is a lucrative industry, but there was little evidence for or against this kind of training leading to cognitive enhancement. This massive study used over 11,000 participants and found that although participants got better at the tasks in the games, no improvement was found in non-trained real-world tasks. Save your money, folks.
9. Outcome Reporting Among Drug Trials
All clinical trials need to be registered through the NIH at clinicaltrials.gov. This policy was designed to prevent Big Pharma from running near-infinite numbers of trials on a drug, then only reporting ones with positive results. This study examines differences between studies funded by industry, by government and by private organizations. Industry-funded trials had 85% positive results, while government-funded trials had 50% positive results. Humph.
10. Prediction of Individual Brain Maturity
Human brains mature rather late and at different rates. The issue of brain maturity has been key to policy decisions about how to punish adolescent criminals and how to insure adolescent drivers. This study uses fMRI to show how mature an individual brain is.
Killingsworth MA, & Gilbert DT (2010). A wandering mind is an unhappy mind. Science (New York, N.Y.), 330 (6006) PMID: 21071660
Cohen Kadosh R, Soskic S, Iuculano T, Kanai R, & Walsh V (2010). Modulating neuronal activity produces specific and long-lasting changes in numerical competence. Current biology : CB, 20 (22), 2016-20 PMID: 21055945
Job V, Dweck CS, & Walton GM (2010). Ego depletion--is it all in your head?: implicit theories about willpower affect self-regulation. Psychological science : a journal of the American Psychological Society / APS, 21 (11), 1686-93 PMID: 20876879
Vollenweider FX, & Kometer M (2010). The neurobiology of psychedelic drugs: implications for the treatment of mood disorders. Nature reviews. Neuroscience, 11 (9), 642-51 PMID: 20717121
Loetscher, T., Bockisch, C., Nicholls, M., & Brugger, P. (2010). Eye position predicts what number you have in mind Current Biology, 20 (6) DOI: 10.1016/j.cub.2010.01.015
Monti, M., Vanhaudenhuyse, A., Coleman, M., Boly, M., Pickard, J., Tshibanda, L., Owen, A., & Laureys, S. (2010). Willful Modulation of Brain Activity in Disorders of Consciousness New England Journal of Medicine, 362 (7), 579-589 DOI: 10.1056/NEJMoa0905370
Owen, A., Hampshire, A., Grahn, J., Stenton, R., Dajani, S., Burns, A., Howard, R., & Ballard, C. (2010). Putting brain training to the test Nature, 465 (7299), 775-778 DOI: 10.1038/nature09042
Bourgeois FT, Murthy S, & Mandl KD (2010). Outcome reporting among drug trials registered in ClinicalTrials.gov. Annals of internal medicine, 153 (3), 158-66 PMID: 20679560
Dosenbach NU, Nardos B, Cohen AL, Fair DA, Power JD, Church JA, Nelson SM, Wig GS, Vogel AC, Lessov-Schlaggar CN, Barnes KA, Dubis JW, Feczko E, Coalson RS, Pruett JR Jr, Barch DM, Petersen SE, & Schlaggar BL (2010). Prediction of individual brain maturity using fMRI. Science (New York, N.Y.), 329 (5997), 1358-61 PMID: 20829489
Sunday soundbites: Happy Boxing Day!
YGERC6QPEMCG
Here is an article I wish I'd written: links between the disease semantic dementia and the insomniac memory loss in Gabriel Garcia Marquez' One Hundred Years of Solitude.
PLoS ONE publishes a study flying in the face of placebo theory showing that patients aware of placebo treatment still show a placebo effect. Study is here, and skeptical analysis found here and here.
Andrew Gelman has a great analysis of why summary plots don't show the whole story.
Nature shows the value of networking in science.
Counting calories? You can blame Lavoisier for first understanding the body as a combustion engine, according to Nature's history of nutrition information.
The journal Biology Letters published this paper by a group of 8th graders. It will be freely available online until the New Year.
How much are those Nature papers really worth? A new study examines citation rates of Nature and Psychological Review.
Bad Science has a great "Year in Nonsense" article for the cynical.
Have some fun doing recreational probability with Understanding Uncertainty.
The science of a good first impression, over at Pop Economics.
Here is an article I wish I'd written: links between the disease semantic dementia and the insomniac memory loss in Gabriel Garcia Marquez' One Hundred Years of Solitude.
PLoS ONE publishes a study flying in the face of placebo theory showing that patients aware of placebo treatment still show a placebo effect. Study is here, and skeptical analysis found here and here.
Andrew Gelman has a great analysis of why summary plots don't show the whole story.
Nature shows the value of networking in science.
Counting calories? You can blame Lavoisier for first understanding the body as a combustion engine, according to Nature's history of nutrition information.
The journal Biology Letters published this paper by a group of 8th graders. It will be freely available online until the New Year.
How much are those Nature papers really worth? A new study examines citation rates of Nature and Psychological Review.
Bad Science has a great "Year in Nonsense" article for the cynical.
Have some fun doing recreational probability with Understanding Uncertainty.
The science of a good first impression, over at Pop Economics.
Monday, December 20, 2010
Why no one bats .299 in late September
This paper shows that people strive for round-number goals, showing evidence from Major League baseball players, high school students taking the SAT, and from laboratory subjects answering hypothetical surveys of behavior.
As can be seen in the figure, baseball players are 4 times more likely to end the season with a 0.300 batting average than a 0.299 average! How does this happen? Players that are at 0.298 or 0.299 are more likely to have at-bats (rather than having a pinch hitter), they are slightly more likely to have hits at those at bats, and once a batter hits the magic 0.300 point, batters often take walks and sit out for pinch hitters.
The SAT takers were 10-20 percentage points more likely to re-take the test if they had an exam ending in -90 (e.g. 1190) than one ending in -00 (e.g. 1200).
Last, the authors gathered laboratory participants and asked them how they would react given certain situations. To give an example situation, imagine running laps around a track and you are getting tired. You have run either 28, 29, 30 or 31 laps (depending on what condition you are in). Do you want to run one more lap? They found that participants in the just under a round number condition (29 laps) were more likely to run one more, and participants in the just over the round number (31) were less likely to do one more.
Are these round number goals rational? In other words, is a baseball player more likely to get a lucrative contract with a 0.300 batting average than a 0.299? Do highly selective colleges have round number cut-offs for admissions? The authors examined data from university admissions that showed no discontinuities in the probability of admission as a function of SAT score, suggesting that such round number goals are not, in fact, rational.
Pope D, & Simonsohn U (2010). Round Numbers as Goals: Evidence From Baseball, SAT Takers, and the Lab. Psychological science : a journal of the American Psychological Society / APS PMID: 21148460
The SAT takers were 10-20 percentage points more likely to re-take the test if they had an exam ending in -90 (e.g. 1190) than one ending in -00 (e.g. 1200).
Are these round number goals rational? In other words, is a baseball player more likely to get a lucrative contract with a 0.300 batting average than a 0.299? Do highly selective colleges have round number cut-offs for admissions? The authors examined data from university admissions that showed no discontinuities in the probability of admission as a function of SAT score, suggesting that such round number goals are not, in fact, rational.
Pope D, & Simonsohn U (2010). Round Numbers as Goals: Evidence From Baseball, SAT Takers, and the Lab. Psychological science : a journal of the American Psychological Society / APS PMID: 21148460
Sunday, December 19, 2010
Sunday soundbites: Rocky Mountain High edition
Not neuro-related, but terrifying: 5% of Boston high school students report carrying guns to school, and think that more people carry guns than actually do.
Nature recognizes the role (they don't seem sure what kind, though) of blogs in scientific discourse.
The New York Times has a nice review of Antonio Damasio's new book The Self Comes to Mind.
Psychology Today has a top ten psychology studies of the year article.
In the spirit of top tens, ScienceNow also has a top ten stories of the year.
Nate Silver of the enviably-fantastic Five Thirty Eight, and himself an orthodox Bayesian, gives a Bayesian take on WikiLeaks' Jullian Assange.
Taking advantage of the open scanner hours now that people are leaving for winter break? Neuroskeptic has the prayer for you.
105 Major League Baseball players have theraputic exemptions for ADHD drugs.
Accelerometers on smart phones used to train prosthetic limbs.
Barking up the Wrong Tree presents an article showing that the Flynn effect (the phenomenon of population IQs rising over time) makes it difficult to have an objective standard for retardation when it comes to capital punishment cases.
Nature recognizes the role (they don't seem sure what kind, though) of blogs in scientific discourse.
The New York Times has a nice review of Antonio Damasio's new book The Self Comes to Mind.
Psychology Today has a top ten psychology studies of the year article.
In the spirit of top tens, ScienceNow also has a top ten stories of the year.
Nate Silver of the enviably-fantastic Five Thirty Eight, and himself an orthodox Bayesian, gives a Bayesian take on WikiLeaks' Jullian Assange.
Taking advantage of the open scanner hours now that people are leaving for winter break? Neuroskeptic has the prayer for you.
105 Major League Baseball players have theraputic exemptions for ADHD drugs.
Accelerometers on smart phones used to train prosthetic limbs.
Barking up the Wrong Tree presents an article showing that the Flynn effect (the phenomenon of population IQs rising over time) makes it difficult to have an objective standard for retardation when it comes to capital punishment cases.
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