Boosting Serotonin Can Speed Learning

I’m sure this research has more implications than currently realized.

Serotonin is thought to mediate communications between neural cells and play an essential role in functional, and dysfunctional, cognition. For a long time, serotonin has been recognized as a major target of antidepressants (selective-serotonin-reuptake-inhibitor (SSRIs) that are used to treat various psychiatric conditions, such as depression, obsessive-compulsive-disorder and forms of anxiety. However, serotonin in humans, and other animals, is associated with a bewildering variety of aspects of cognition and decision-making, including punishment, reward and patience.

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In the experiments, mice were trained to choose one of the two targets to receive water rewards. Mice continually had to learn which of the targets was more rewarding, as the reward rates changed without warning. Crucially, sometimes serotonin release in the brain was temporarily boosted in mice with genetically modified serotonin neurons by a technique called optogenetics, allowing the effects of serotonin on learning to be assessed.

Iigaya built a computational account of mice behaviour based on reinforcement learning principles, which are widely used in machine-learning and AI. Iigaya found that the learning rate, i.e. how fast the modelled mice learn, was modulated by serotonin stimulation. He compared trials with and without stimulation of serotonin neurons, and observed that the learning rate was significantly faster when stimulation was delivered, meaning that boosting serotonin sped up learning in mice.

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The authors conclude: “Our results suggest that serotonin boosts [brain] plasticity by influencing the rate of learning. This resonates, for instance, with the fact that treatment with an SSRI can be more effective when combined with so-called cognitive behavioral therapy, which encourages the breaking of habits in patients.”

Substantial clinical research shows that SSRI treatment is often most effective if combined with cognitive-behavioural-therapy (CBT). The goal of CBT is to change maladaptive thinking and behaviour actively, through sessions that are designed for patients to (re)learn their way to think and behave. However, scientists have had limited understanding of how and why SSRI and CBT work together for treatments. The new findings point to a possible functional link between the two, with serotonin boosting the learning inherent to CBT, providing clues as to one of the roles that this neuromodulator plays in the treatment of psychiatric disorders.

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Brain’s Window for Easy Language Learning Open a Decade Longer Than Previously Thought

Various educational systems may now be changed as a result of this research.
In a study of nearly 700,000 English speakers, researchers from Boston College, MIT and Harvard have discovered the optimal years to learn a second language extend to the cusp of adulthood, the team reports today in the online edition of the journal Cognition.

It has long been known that children learn language more easily than adults, but determining exactly when that ability declines has been something of a mystery.

Benefitting from a massive study population and new research methods that allowed them to separate interconnected factors in language acquisition, the team reports that the window for language learning is open approximately a decade longer than previously thought — until the age of 17.4 years of age.

The new findings hold implications for neuroscience, linguistics, developmental psychology and public policy, according to the co-authors of the report, titled “A Critical Period for Second Language Acquisition: Evidence from 2/3 Million English Speakers.”

“What we’ve found gives us a dramatically different understanding about why children learn a new language more efficiently and completely than adults,” said Boston College Assistant Professor of Psychology Joshua K. Hartshorne, a co-author of the study with MIT Professor Joshua B. Tenenbaum and Harvard Professor Steven Pinker.

The findings are the first to estimate how long humans can learn grammar and how that ability changes with age. The ability extends to early adulthood before it begins to decline, the researchers found. This proved so for both “easy” and “difficult” syntaxes the team used in their study.

The findings define a clear “critical period for language acquisition” that lasts much longer than previously thought.

“Explaining this ‘critical period for language acquisition’ is crucial not only for understanding why humans, but not animals or machines, learn language, but also for research questions on neural development and plasticity, bilingual education, foreign language education, treatment of disorders that affect language, and early childhood stimulation,” Hartshorne said.

Tens of thousands of respondents from around the world took the survey through a quiz the researchers offered online through the site http://www.gameswithwords.org, Hartshorne said.

He added that earlier studies focused on how much language a seven-year-old could expect to eventually learn, rather than how quickly a seven-year-old learns language.

Too Much Time in Dimly Lit Rooms May Decrease Intelligence, Neuroscience Research Finds

There’s a lot that could be said about this and the structural effects from it.

Spending too much time in dimly lit rooms and offices may actually change the brain’s structure and hurt one’s ability to remember and learn, indicates groundbreaking research by Michigan State University neuroscientists.

The researchers studied the brains of Nile grass rats (which, like humans, are diurnal and sleep at night) after exposing them to dim and bright light for four weeks. The rodents exposed to dim light lost about 30 percent of capacity in the hippocampus, a critical brain region for learning and memory, and performed poorly on a spatial task they had trained on previously.

The rats exposed to bright light, on the other hand, showed significant improvement on the spatial task. Further, when the rodents that had been exposed to dim light were then exposed to bright light for four weeks (after a month-long break), their brain capacity — and performance on the task — recovered fully.

The study, funded by the National Institutes of Health, is the first to show that changes in environmental light, in a range normally experienced by humans, leads to structural changes in the brain. Americans, on average, spend about 90 percent of their time indoors, according to the Environmental Protection Agency.

“When we exposed the rats to dim light, mimicking the cloudy days of Midwestern winters or typical indoor lighting, the animals showed impairments in spatial learning,” said Antonio “Tony” Nunez, psychology professor and co-investigator on the study. “This is similar to when people can’t find their way back to their cars in a busy parking lot after spending a few hours in a shopping mall or movie theater.”

Nunez collaborated with Lily Yan, associate professor of psychology and principal investigator on the project, and Joel Soler, a doctoral graduate student in psychology. Soler is also lead author of a paper on the findings published in the journal Hippocampus.

Soler said sustained exposure to dim light led to significant reductions in a substance called brain derived neurotrophic factor — a peptide that helps maintain healthy connections and neurons in the hippocampus — and in dendritic spines, or the connections that allow neurons to “talk” to one another.

“Since there are fewer connections being made, this results in diminished learning and memory performance that is dependent upon the hippocampus,” Soler said.

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The project could have implications for the elderly and people with glaucoma, retinal degeneration or cognitive impairments.

“For people with eye disease who don’t receive much light, can we directly manipulate this group of neurons in the brain, bypassing the eye, and provide them with the same benefits of bright light exposure?” Yan said. “Another possibility is improving the cognitive function in the aging population and those with neurological disorders. Can we help them recover from the impairment or prevent further decline?”

Study: Video Game Players Have an Advantage in Learning

There could be some value to these results. Video games in moderation may be better than prescription drugs (which too often have negative side effects) at treating learning difficulties, for example.

Neuropsychologists of the Ruhr-Universität Bochum let video gamers compete against non-gamers in a learning competition. During the test, the video gamers performed significantly better and showed an increased brain activity in the brain areas that are relevant for learning. Prof Dr Boris Suchan, Sabrina Schenk and Robert Lech report their findings in the journal Behavioural Brain Research.

The weather prediction task

The research team studied 17 volunteers who — according to their own statement — played action-based games on the computer or a console for more than 15 hours a week. The control group consisted of 17 volunteers who didn’t play video games on a regular basis. Both teams did the so-called weather prediction task, a well-established test to investigate the learning of probabilities. The researchers simultaneously recorded the brain activity of the participants via magnetic resonance imaging.

The participants were shown a combination of three cue cards with different symbols. They should estimate whether the card combination predicted sun or rain and got a feedback if their choice was right or wrong right away. The volunteers gradually learned, on the basis of the feedback, which card combination stands for which weather prediction. The combinations were thereby linked to higher or lower probabilities for sun and rain. After completing the task, the study participants filled out a questionnaire to sample their acquired knowledge about the cue card combinations.

Video gamers better with high uncertainties

The gamers were notably better in combining the cue cards with the weather predictions than the control group. They fared even better with cue card combinations that had a high uncertainty such as a combination that predicted 60 percent rain and 40 percent sunshine.

The analysis of the questionnaire revealed that the gamers had acquired more knowledge about the meaning of the card combinations than the control group. “Our study shows that gamers are better in analysing a situation quickly, to generate new knowledge and to categorise facts — especially in situations with high uncertainties,” says first author Sabrina Schenk.

This kind of learning is linked to an increased activity in the hippocampus, a brain region that plays a key role in learning and memory. “We think that playing video games trains certain brain regions like the hippocampus,” says Schenk. “That is not only important for young people, but also for older people; this is because changes in the hippocampus can lead to a decrease in memory performance. Maybe we can treat that with video games in the future.”