Thursday, July 31, 2014

Logarithms Celebrate Their 400th Birthday

You may find this hard to believe, but there are people still alive today who once did their mathematical calculations by sliding sticks back and forth. No keypads, no batteries, no LEDs. Just sticks. Yes, it sounds like a device from the Stone Age, but as late as the 1970s scientists and engineers commonly used such a stick-sliding device, known as a slide rule, to perform multiplication and division and other tasks like extracting square roots. Working versions of these instruments still are on display in museums today. But as primitive as they sound, slide rules could not have been invented in the Stone Age or even in ancient Greece. They owe their existence to a much later mathematical development that is celebrating its 400th anniversary this year: the invention of logarithms. more

Wednesday, July 30, 2014

The Gene That Turns Worms Into Pavlov’s Dogs

Like Pavlov’s dogs, most organisms can learn to associate two events that usually occur together. Now, a team of researchers says they have identified a gene that enables such learning. The scientists, at the University of Tokyo, found that worms could learn to avoid unpleasant situations as long as a specific insulin receptor remained intact. Roundworms were exposed to different concentrations of salt; some received food during the initial exposure, others did not. Later, when exposed to various concentrations of salt again, the roundworms that had been fed during the first stage gravitated toward their initial salt concentrations, while those that had been starved avoided them. But the results changed when the researchers repeated the experiment using worms with a defect in a particular receptor for insulin, a protein crucial to metabolism. Those worms could not learn to avoid the salt concentrations associated with starvation. more

Thursday, July 24, 2014

Monetary Reward Speeds Up Voluntary Saccades

Past studies have shown that reward contingency is critical for sensorimotor learning, and reward expectation speeds up saccades in animals. Whether monetary reward speeds up saccades in human remains unknown. Here we addressed this issue by employing a conditional saccade task, in which human subjects performed a series of non-reflexive, visually-guided horizontal saccades. The subjects were (or were not) financially compensated for making a saccade in response to a centrally-displayed visual congruent (or incongruent) stimulus. Reward modulation of saccadic velocities was quantified independently of the amplitude-velocity coupling. We found that reward expectation significantly sped up voluntary saccades up to 30°/s, and the reward modulation was consistent across tests. These findings suggest that monetary reward speeds up saccades in human in a fashion analogous to how juice reward sped up saccades in monkeys. We further noticed that the idiosyncratic nasal-temporal velocity asymmetry was highly consistent regardless of test order, and its magnitude was not correlated with the magnitude of reward modulation. This suggests that reward modulation and the intrinsic velocity asymmetry may be governed by separate mechanisms that regulate saccade generation. more

Tuesday, July 22, 2014

A Troublesome Inheritance: Genes, Race, and Human History

In his new book, A Troublesome Inheritance: Genes, Race, and Human History, science writer Nicholas Wade claims that race is real—that Darwinian natural selection has resulted in a number of biologically separate human populations characterized by distinct, genetically determined social behaviors. He asserts that many of these differences have emerged over the last 10,000 years and that they explain much of human history. He writes that recent science has “established that human evolution has been recent, copious, and regional” and uses this framework to account for regional variations in economic power and cultural pursuits. As soon as it appeared, Wade’s book touched off a firestorm of controversy—as he surely knew it would...Early reviews of Wade’s book show a familiar division: Anthropologists mostly take a critical view, whereas psychologists and economists generally like the book...So is Wade right? Are there human races? Is the variation seen between different cultures and locations best explained by genetic differences between human populations? And have anthropologists been turning a blind eye to the evidence in front of them? There is no shortage of scientific information, and it gives a clear answer: no. more

Friday, July 18, 2014

Crack Down on Scientific Fraudsters

Ong-Pyou Han needed impressive lab results to help his team at Iowa State University move forward with its work on an AIDS vaccine — and to continue receiving millions of dollars in federal grants. So Dr. Han did what many scientists are probably tempted to do, but don’t: He faked the tests, spiking rabbit blood with human proteins to make it appear that the animals were responding to the vaccine to fight H.I.V. The reason you’re reading about this story, and not about the glowing success of the therapy, is that Dr. Han was caught... Even though research misconduct is far from rare, Dr. Han’s case was unusual in that he had to resign. Criminal charges against scientists who commit fraud are even more uncommon. In fact, according to a study published last year, “most investigators who engage in wrongdoing, even serious wrongdoing, continue to conduct research at their institutions.” As part of our reporting, we’ve written about multiple academic researchers who have been found guilty of misconduct and then have gone on to work at pharmaceutical giants. more

Thursday, July 17, 2014

Operant Conditioning of Spinal Reflexes: From Basic Science to Clinical Therapy

New appreciation of the adaptive capabilities of the nervous system, recent recognition that most spinal cord injuries are incomplete, and progress in enabling regeneration are generating growing interest in novel rehabilitation therapies. Here we review the 35-year evolution of one promising new approach, operant conditioning of spinal reflexes. This work began in the late 1970’s as basic science; its purpose was to develop and exploit a uniquely accessible model for studying the acquisition and maintenance of a simple behavior in the mammalian central nervous system (CNS). The model was developed first in monkeys and then in rats, mice, and humans. Studies with it showed that the ostensibly simple behavior (i.e., a larger or smaller reflex) rests on a complex hierarchy of brain and spinal cord plasticity; and current investigations are delineating this plasticity and its interactions with the plasticity that supports other behaviors. In the last decade, the possible therapeutic uses of reflex conditioning have come under study, first in rats and then in humans. The initial results are very exciting, and they are spurring further studies. At the same time, the original basic science purpose and the new clinical purpose are enabling and illuminating each other in unexpected ways. The long course and current state of this work illustrate the practical importance of basic research and the valuable synergy that can develop between basic science questions and clinical needs. more

Tuesday, July 15, 2014

Scientists’ Grasp of Confidence Intervals Doesn’t Inspire Confidence

Sometimes it’s hard to have confidence in science. So many results from published scientific studies turn out to be wrong. Part of the problem is that science has trouble quantifying just how confident in a result you should be. Confidence intervals are supposed to help with that. They’re like the margin of error in public opinion polls. If candidate A is ahead of candidate B by 2 percentage points, and the margin of error is 4 percentage points, then you know it’s not a good bet to put all your money on A. The difference between the two is not “statistically significant.” Traditionally, science has expressed statistical significance with P values, P standing for the probability that the result you observe is a fluke. P values have all sorts of problems...Consequently many experts have advised using confidence intervals instead, and their use is becoming increasingly common. While there are some advantages in that, it is sadly the case that confidence intervals are also not what they are commonly represented to be. more

Monday, July 14, 2014

EveryMove Leaps Past Traditional Fitness Tracking To Deliver A Network Of Positive Reinforcement

EveryMove, the world’s first fitness tracking network, today unveiled a fresh new mobile app and website to deliver even more benefits for living an active lifestyle. Since its launch in 2012, EveryMove has demonstrated that unifying an individual’s fitness data gives them influence across a broad network of partners that want to reward and recognize an active lifestyle. “It doesn’t matter how consumers track their activity or what activities they prefer. What we care about is that they are getting consistent feedback from a personalized network that recognizes progress,” says Russell Benaroya, CEO of EveryMove. “EveryMove has created the one network where friends, employers, health plans, and brands can rally around each individual in a fun and engaging way to turn fitness into real-life tangible benefits.” more

Wednesday, July 09, 2014

A Shocking Way to Keep Fit: Band Gives You an Electric Jolt If You Don’t Exercise Enough

It is the wristband that could literally jolt you in action--by giving its wearer an electric shock if they don't reach their fitness goals or hit their work deadline. Called Pavlok, it uses the idea of positive reinforcement to try and change a user's behavior. Its makers hope it could go on sale this year - and be far more effective than current tracking bands...Negative reinforcement "really does make people pay attention," he said. According to the firm's website,"Pavlok offers a simple, wearable device that helps consumers form better habits." Using psychologically proven and user tested algorithms, the Pavlok wristband enforces users’ commitments to fitness, productivity, and more — even if that means 'sparking' their commitment by delivering a mild (but jolting) electric shock." more

The Push to Screen Statistics in Papers

The journal Science is adding an extra round of statistical checks to its peer-review process, editor-in-chief Marcia McNutt announced today. The policy follows similar efforts from other journals, after widespread concern that basic mistakes in data analysis are contributing to the irreproducibility of many published research findings. “Readers must have confidence in the conclusions published in our journal,” writes McNutt in an editorial today. Working with the American Statistical Association, the journal has appointed seven experts to a statistics board of reviewing editors (SBoRE). Manuscript will be flagged up for additional scrutiny by the journal’s internal editors, or by its existing Board of Reviewing Editors (more than 100 scientists whom the journal regularly consults on papers) or by outside peer reviewers. The SBoRE panel will then find external statisticians to review these manuscripts. more

Tuesday, July 08, 2014

Habituation, Sensitization, and Pavlovian Conditioning

In this brief review, I argue that the impact of a stimulus on behavioral control increase as the distance of the stimulus to the body decreases. Habituation, i.e., decrement in response intensity repetition of the triggering stimulus, is the default state for sensory processing, and the likelihood of habituation is higher for distal stimuli. Sensitization, i.e., increment in response intensity upon stimulus repetition, occurs in a state dependent manner for proximal stimuli that make direct contact with the body. In Pavlovian conditioning paradigms, the unconditioned stimulus (US) is always a more proximal stimulus than the conditioned stimulus (CS). The mechanisms of associative and non-associative learning are not independent. CS−US pairings lead to formation of associations if sensitizing modulation from a proximal US prevents the habituation for a distal anticipatory CS. more

Monday, July 07, 2014

Operant Conditioning: Why YouTube Beats Facebook in Fan Engagement

Recently I wrote about engagement rates in brand communities on YouTube versus Facebook; the data I gathered suggests that Facebook communities may be larger, but YouTube engagement runs far deeper. The question is why? I think the answer lies in some of the fundamental principles of behavioral psychology. The top performing YouTube creators are masters of building communities—and have spent the last few years building them from the ground up. And whether they’re consciously aware of it or not, the creators with the largest followings leverage one of the fundamental concepts in behavioral psychology: operant conditioning. more

Thursday, July 03, 2014

Smarter Than You Think: Fish Can Remember Where They Were Fed 12 Days Later

It is popularly believed that fish have a memory span of only 30 seconds. Canadian scientists, however, have demonstrated that this is far from true – in fact, fish can remember context and associations up to twelve days later. The researchers studied African Cichlids (Labidochromis caeruleus), a popular aquarium species. These fish demonstrate many complex behaviours, including aggression, causing the scientists to predict that they could be capable of advanced memory tasks. Each fish was trained to enter a particular zone of the aquarium to receive a food reward, with each training session lasting twenty minutes. After three training days, the fish were given a twelve day rest period. The fish were then reintroduced into their training arena and their movements recorded with motion-tracking software. It was found that the cichlids showed a distinct preference for the area associated with the food reward, suggesting that they recalled the previous training experiences. Furthermore, the fish were able to reverse this association after further training sessions where the food reward was associated with a different stimulus. more

Tuesday, July 01, 2014

Why We Aren’t The Parents We Know We Could Be

Most parents I know suffer from occasional — or constant — eruptions of parental self-judgment: moments when they feel they fall short of being the parents they could be. There’s a gap between what they know about effective parenting (in the abstract) and what actually happens in everyday practice — in the car, in the supermarket, in the living room...Of course, there are all sorts of reasons why “knowing better” doesn’t always translate into “doing better”: we’re busy and exhausted, we’re lazy and set in our ways. Plus, it isn’t always obvious when and how the abstract applies to the concrete. But it turns out that one of the most important lessons from psychology about how to change children’s behavior is also the key to why knowledge of better parenting is rarely enough to make us better parents. The lesson is this: to encourage a behavior, you need to generate the best conditions for it to arise and then reinforce the heck out of it. Merely knowing what you should do is often insufficient to reliably bring the behavior about and merely knowing doesn’t offer much in the way of reinforcement. more