Posts tagged learning

The best way to learn is to teach. Now a classroom robot that helps Japanese children learn English has put that old maxim to the test.

(Image: Sinopix/Rex Features)

Shizuko Matsuzoe and Fumihide Tanaka at the University of Tsukuba, Japan, set up an experiment to find out how different levels of competence in a robot teacher affected children’s success in learning English words for shapes.

They observed how 19 children aged between 4 and 8 interacted with a humanoid Nao robot in a learning game in which each child had to draw the shape that corresponded to an English word such as ‘circle’, ‘square’, ‘crescent’, or ‘heart’.

The researchers operated the robot from a room next to the classroom so that it appeared weak and feeble, and the children were encouraged to take on the role of carers. The robot could then either act as an instructor, drawing the correct shape for the child, or make mistakes and act as if it didn’t know the answer.

When the robot got a shape wrong, the child could teach the robot how to draw it correctly by guiding its hand. The robot then either “learned” the English word for that shape or continued to make mistakes.

Robot learner aids learning

Matsuzoe and Tanaka found that the children did best when the robot appeared to learn from them. This also made the children more likely to want to continue learning with the robot. The researchers will present their results at Ro-Man - an international symposium on robot and human interactive communication - in September.

"Anything that gets a person more actively engaged and motivated is going to be beneficial to the learning process," says Andrea Thomaz , director of the Socially Intelligent Machines lab at the Georgia Institute of Technology in Atlanta. "So needing to teach the robot is a great way of doing that."

The idea of students learning by teaching also agrees with a lot of research in human social learning, she says. The process of teaching a robot is akin to what happens in peer-to-peer learning, where students teach each other or work in groups to learn concepts – common activities in most classrooms.

Source: NewScientist

26 August 2012 by Mo Costandi

Subjects trained to sniff pleasant smells while asleep retain the conditioning when they wake up.

It sounds like every student’s dream: research published today in Nature Neuroscience shows that we can learn entirely new information while we snooze.

TIPS/Photoshot

Anat Arzi of the Weizmann Institute of Science in Rehovot, Israel, and her colleagues used a simple form of learning called classical conditioning to teach 55 healthy participants to associate odours with sounds as they slept.

They repeatedly exposed the sleeping participants to pleasant odours, such as deodorant and shampoo, and unpleasant odours such as rotting fish and meat, and played a specific sound to accompany each scent.

It is well known that sleep has an important role in strengthening existing memories, and this conditioning was already known to alter sniffing behaviour in people who are awake. The subjects sniff strongly when they hear a tone associated with a pleasant smell, but only weakly in response to a tone associated with an unpleasant one.

But the latest research shows that the sleep conditioning persists even after they wake up, causing them to sniff strongly or weakly on hearing the relevant tone — even if there was no odour. The participants were completely unaware that they had learned the relationship between smells and sounds. The effect was seen regardless of when the conditioning was done during the sleep cycle. However, the sniffing responses were slightly more pronounced in those participants who learned the association during the rapid eye movement (REM) stage, which typically occurs during the second half of a night’s sleep.

Pillow power

Arzi thinks that we could probably learn more complex information while we sleep. “This does not imply that you can place your homework under the pillow and know it in the morning,” she says. “There will be clear limits on what we can learn in sleep, but I speculate that they will be beyond what we have demonstrated.”

In 2009, Tristan Bekinschtein, a neuroscientist at the UK Medical Research Council’s Cognition and Brain Sciences Unit in Cambridge, and his colleagues reported that some patients who are minimally conscious or in a vegetative state can be classically conditioned to blink in response to air puffed into their eyes. Conditioned responses such as these could eventually help clinicians to diagnose these neurological conditions, and to predict which patients might subsequently recover. “It remains to be seen if the neural networks involved in sleep learning are similar to the ones recruited during wakefulness,” says Bekinschtein.

The findings by Arzi and her colleagues might also be useful for these purposes, and could lead to ‘sleep therapies’ that help to alter behaviour in conditions such as phobia.

“We are now trying to implement helpful behavioural modification through sleep-learning,” says Arzi. “We also want to investigate the brain mechanisms involved, and the type of learning we use in other states of altered consciousness, such as vegetative state and coma.”

Source: Nature

ScienceDaily (Aug. 21, 2012) — Working with units of material so small that it would take 50,000 to make up one drop, scientists are developing the profiles of the contents of individual brain cells in a search for the root causes of chronic pain, memory loss and other maladies that affect millions of people.

They described the latest results of this one-by-one exploration of cells or “neurons” from among the millions present in an animal brain at the 244^th National Meeting & Exposition of the American Chemical Society (ACS), the world’s largest scientific society. The meeting, expected to attract almost 14,000 scientists and others from around the world, continues in Philadelphia through Thursday, with 8,600 presentations on new discoveries in science and other topics.

Jonathan Sweedler, Ph.D., a pioneer in the field, explained in a talk at the meeting that knowledge of the chemistry occurring in individual brain cells would provide the deepest possible insights into the causes of certain diseases and could point toward new ways of diagnosis and treatment. Until recently, however, scientists have not had the technology to perform such neuron-by-neuron research.

"Most of our current knowledge about the brain comes from studies in which scientists have been forced to analyze the contents of multiple nerve cells, and, in effect, average the results," Sweedler said. He is with the University of Illinois at Urbana-Champaign and also serves as editor-in-chief of Analytical Chemistry, which is among ACS’ more than 40 peer-reviewed scientific journals. “That approach masks the sometimes-dramatic differences that can exist even between nerve cells that are shoulder-to-shoulder together. Suppose that only a few cells in that population are changing, perhaps as a disease begins to take root or starts to progress or a memory forms and solidifies. Then we would miss those critical changes by averaging the data.”

However, scientists have found it difficult to analyze the minute amounts of material inside single brain cells. Those amounts are in the so-called “nanoliter” range, units so small that it would take 355 billion nanoliters to fill a 12-ounce soft-drink can. Sweedler’s group spent much of the past decade developing the technology to analyze the chemicals found in individual cells — a huge feat with a potentially big pay-off. “We are using our new approaches to understand what happens in learning and memory in the healthy brain, and we want to better understand how long-lasting, chronic pain develops,” he said.

The 85 billion neurons in the brain are highly interconnected, forming an intricate communications network that makes the complexity of the Internet pale in comparison. The neural net’s chemical signaling agents and electrical currents orchestrate a person’s personality, thoughts, consciousness and memories. These connections are different from person to person and change over the course of a lifetime, depending on one’s experiences. Even now, no one fully understands how these processes happen.

To get a handle on these complex workings, Sweedler’s team and others have zeroed in on small sections of the central nervous system ― the brain and spinal cord ― using stand-ins for humans such as sea slugs and laboratory rats. Sweedler’s new methods enable scientists to actually select areas of the nervous system, spread out the individual neurons onto a glass surface, and one-by-one analyze the proteins and other substances inside each cell.

One major goal is to see how the chemical make-up of nerve cells changes during pain and other disorders. Pain from disease or injuries, for instance, is a huge global challenge, responsible for 40 million medical appointments annually in the United States alone.

Sweedler reported that some of the results are surprising, including tests on cells in an area of the nervous system involved in the sensation of pain. Analysis of the minute amounts of material inside the cells showed that the vast majority of cells undergo no detectable change after a painful event. The chemical imprint of pain occurs in only a few cells. Finding out why could point scientists toward ways of blocking those changes and in doing so, could lead to better ways of treating pain.

Source: Science Daily

ScienceDaily (Aug. 15, 2012) — Long-term methadone treatment can cause changes in the brain, according to recent studies from the Norwegian Institute of Public Health. The results show that treatment may affect the nerve cells in the brain. The studies follow on from previous studies where methadone was seen to affect cognitive functioning, such as learning and memory.

Since it is difficult to perform controlled studies of methadone patients and unethical to attempt in healthy volunteers, rats were used in the studies. Previous research has shown that methadone can affect cognitive functioning in both humans and experimental animals.

Sharp decrease in key signaling molecule

Rats were given a daily dose of methadone for three weeks. Once treatment was completed, brain areas which are central for learning and memory were removed and examined for possible neurobiological changes or damage.

In one study, on the day after the last exposure to methadone, there was a significant reduction (around 70 per cent) in the level of a signal molecule which is important in learning and memory, in both the hippocampus and in the frontal area of the brain. This reduction supports findings from a previous study (Andersen et al., 2011) where impaired attention in rats was found at the same time. At this time, methadone is no longer present in the brain. This indicates that methadone can lead to cellular changes that affect cognitive functioning after the drug has left the body, which may be cause for concern.

No effect on cell generation

The second study, a joint project with Southwestern University in Texas, investigated whether methadone affects the formation of nerve cells in the hippocampus. Previous research has shown that new nerve cells are generated in the hippocampus in both adult humans and rats, and that this formation is probably important for learning and memory. Furthermore, it has been shown that other opiates such as morphine and heroin can inhibit this formation. It was therefore reasonable to assume that methadone, which is also an opiate, would have the same effect.

However, the researchers did not find any change in the generation of new nerve cells after long-term methadone treatment. If the same is true in humans, this is probably more positive for methadone patients than continuing with heroin. However, the researchers do not know what effect methadone has on nerve cells that have previously been exposed to heroin.

Large gaps in knowledge

Since the mid-1960s, methadone has been used to treat heroin addiction. This is considered to be a successful treatment but, despite extensive and prolonged use, little is known about possible side effects. There are large knowledge gaps in this field.

Our studies show that prolonged methadone treatment can affect the nerve cells, and thus behaviour, but the results are not always as expected. Many more pre-clinical and clinical studies are needed to understand methadone’s effect on the brain, how this can result in altered cognitive function, and, if so, how long these changes last. Knowledge of this is important — both for the individual methadone patient and the outcome of treatment.

Source: Science Daily

ScienceDaily (Aug. 8, 2012) — Stressed and non-stressed people use different brain regions and different strategies when learning. This has been reported by the cognitive psychologists PD Dr. Lars Schwabe and Professor Oliver Wolf from the Ruhr-Universität Bochum in the Journal of Neuroscience. Non-stressed individuals applied a deliberate learning strategy, while stressed subjects relied more on their gut feeling. “These results demonstrate for the first time that stress has an influence on which of the different memory systems the brain turns on,” said Lars Schwabe.

The experiment: Stress due to ice-water

The data from 59 subjects were included in the study. Half of the participants had to immerse one hand into ice-cold water for three minutes under video surveillance. This stressed the subjects, as hormone assays showed. The other participants had to immerse one of their hands just in warm water. Then both the stressed and non-stressed individuals completed the so-called weather prediction task. The subjects looked at playing cards with different symbols and learned to predict which combinations of cards announced rain and which sunshine. Each combination of cards was associated with a certain probability of good or bad weather. People apply differently complex strategies in order to master the task. During the weather prediction task, the researchers recorded the brain activity with MRI.

Two routes to success

Both stressed and non-stressed subjects learned to predict the weather according to the symbols. Non-stressed participants focused on individual symbols and not on combinations of symbols. They consciously pursued a simple strategy. The MRI data showed that they activated a brain region in the medial temporal lobe — the hippocampus, which is important for long-term memory. Stressed subjects, on the other hand, applied a more complex strategy. They made their decisions based on the combination of symbols. They did this, however, subconsciously, i.e. they were not able to formulate their strategy in words. The result of the brain scans was also accordingly: In the case of the stressed volunteers the so-called striatum in the mid-brain was activated — a brain region that is responsible for more unconscious learning. “Stress interferes with conscious, purposeful learning, which is dependent upon the hippocampus,” concluded Lars Schwabe. “So that makes the brain use other resources. In the case of stress, the striatum controls behaviour — which saves the learning achievement.”

Source: Science Daily