donderdag 3 maart 2016

The danger of concussions

It is becoming increasingly clear that concussions have long term effects - and not only for boxers. The Economist (Bang to rights: Science is taking big steps toward understanding the impact of concussion) gives an overview. In recent years the underlying biology has started to become apparent. Mostly, this relates to the release of certain chemicals when axons, the filamentous connections between nerve cells, are damaged. Concussion is different from blunt-force trauma, such as that which results from getting hit on the head by a rapidly delivered cricket ball. Then, the injury is caused by directly transmitted shock from the impact. Concussion, by contrast, is caused by the internal movement and distortion of the brain as it bounces around inside the cranium after an impact. This bouncing, research has shown, stretches and deforms bundles of axons that connect different regions of the brain. The deformation shears some axons directly, releasing their protein contents, including tau, which with time can form abnormal tangles similar to those found in Alzheimer’s disease. It also causes abnormal inflows of sodium and calcium ions in unsevered but damaged axons. These, in turn, trigger a process which releases protein-breaking enzymes that destroy the axon, further disrupting the brain’s internal communications. Concussive injury also damages the blood-brain barrier. This is a system of tightly joined cells surrounding the capillaries that service the brain. Its purpose is to control what enters and leaves the central nervous system. One consequence of damaging it is to release into general circulation a brain protein called S100B. The body mounts an immune response against this protein, and the antibodies it generates can find their way back into the brain and harm healthy brain cells. Researchers propose that repeated damage could set the stage for a continuous autoimmune-type attack on the brain. But the long term effects are still unclear. There are efforts to develop a blood test with which you could measure the seriousness of a concussion - by measuring one of chemicals involved. Finally the harm caused by concussions with children is discussed: Yet it has been clear since a study published in 2012 by Andrew Mayer at the University of New Mexico in Albuquerque that subtle brain changes in children who have sustained a concussion persist for months after the injury, even when there are no longer any obvious symptoms. Work published last December by Charles Hillman of the University of Illinois found that children who had sustained a single sports-related concussion still had impaired brain function two years later. Ten-year-olds with a history of concussion performed worse on tests of working memory, attention and impulse control than did uninjured confrères. Among the children with a history of concussion, those who were injured earlier in life had larger deficits. This study was small (it involved 15 injured participants) but if subsequent research confirms it, that will be great cause for concern.

zaterdag 27 februari 2016

What makes teams successful

An interesting article ("What Google Learned From Its Quest to Build the Perfect Team") analyzes what makes teams successful. The article discusses research at Google on what makes teams successful. It starts with the conclusion that many things - like the composition of the group - don't seem to have influence. Then it turns to group norms. Here it becomes interesting. To accomplish this, the researchers recruited 699 people, divided them into small groups and gave each a series of assignments that required different kinds of cooperation. One assignment, for instance, asked participants to brainstorm possible uses for a brick. Some teams came up with dozens of clever uses; others kept describing the same ideas in different words. Another had the groups plan a shopping trip and gave each teammate a different list of groceries. The only way to maximize the group’s score was for each person to sacrifice an item they really wanted for something the team needed. Some groups easily divvied up the buying; others couldn’t fill their shopping carts because no one was willing to compromise. What interested the researchers most, however, was that teams that did well on one assignment usually did well on all the others. Conversely, teams that failed at one thing seemed to fail at everything. The researchers eventually concluded that what distinguished the ‘‘good’’ teams from the dysfunctional groups was how teammates treated one another. The right norms, in other words, could raise a group’s collective intelligence, whereas the wrong norms could hobble a team, even if, individually, all the members were exceptionally bright. They found some common themes in successful teams: - on the good teams, members spoke in roughly the same proportion, a phenomenon the researchers referred to as ‘‘equality in distribution of conversational turn-taking.’’ On some teams, everyone spoke during each task; on others, leadership shifted among teammates from assignment to assignment. But in each case, by the end of the day, everyone had spoken roughly the same amount. ‘‘As long as everyone got a chance to talk, the team did well,’’ Woolley said. ‘‘But if only one person or a small group spoke all the time, the collective intelligence declined.’’ - the good teams all had high ‘‘average social sensitivity’’ — a fancy way of saying they were skilled at intuiting how others felt based on their tone of voice, their expressions and other nonverbal cues. One of the easiest ways to gauge social sensitivity is to show someone photos of people’s eyes and ask him or her to describe what the people are thinking or feeling — an exam known as the Reading the Mind in the Eyes test. People on the more successful teams in Woolley’s experiment scored above average on the Reading the Mind in the Eyes test. They seemed to know when someone was feeling upset or left out. People on the ineffective teams, in contrast, scored below average. They seemed, as a group, to have less sensitivity toward their colleagues. -- There were other behaviors that seemed important as well — like making sure teams had clear goals and creating a culture of dependability. But Google’s data indicated that psychological safety, more than anything else, was critical to making a team work. Together these two concept are called "psychological safety", a group culture that the Harvard Business School professor Amy Edmondson defines as a ‘‘shared belief held by members of a team that the team is safe for interpersonal risk-taking.’’ Psychological safety is ‘‘a sense of confidence that the team will not embarrass, reject or punish someone for speaking up,’’ Edmondson wrote in a study published in 1999. ‘‘It describes a team climate characterized by interpersonal trust and mutual respect in which people are comfortable being themselves.’’

zondag 31 januari 2016

The social life of trees

According to a very popular book by Peter Wohlleben (Das geheime Leben der Baüme) trees have a social life too: the news — long known to biologists — that trees in the forest are social beings. They can count, learn and remember; nurse sick neighbors; warn each other of danger by sending electrical signals across a fungal network known as the “Wood Wide Web”; and, for reasons unknown, keep the ancient stumps of long-felled companions alive for centuries by feeding them a sugar solution through their roots. [] Reading up on the behavior of trees — a topic he learned little about in forestry school — he found that, in nature, trees operate less like individuals and more as communal beings. Working together in networks and sharing resources, they increase their resistance. By artificially spacing out trees, the plantation forests that make up most of Germany’s woods ensure that trees get more sunlight and grow faster. But, naturalists say, creating too much space between trees can disconnect them from their networks, stymieing some of their inborn resilience mechanisms. Intrigued, Mr. Wohlleben began investigating alternate approaches to forestry. Visiting a handful of private forests in Switzerland and Germany, he was impressed. “They had really thick, old trees,” he said. “They treated their forest much more lovingly, and the wood they produced was more valuable. In one forest, they said, when they wanted to buy a car, they cut two trees. For us, at the time, two trees would buy you a pizza.”

Another look at creativity

The NY Times has an article Scientists Move Closer to Understanding Schizophrenia’s Cause. They found a clear correlation between a gene connected to pruning brain cell connections and schizophrenia. This gene is far from the only cause, but the correlation is clear. It also explains why schizophrenia usually start in late adolescence or early adulthood when pruning is strongest. Now creativity is often correlated with schizophrenia. So it would be logical to assume that this might somehow be correlated with pruning too. One theory of creativity holds that creative people have so much links in their brain that other people don't have. That would suggest that they have less pruning. However, my view is that the main thing that discerns creative people is not more ideas but less filtering. In that context it looks like that all those extra links in less creative people serve as brakes that make that ideas are rejected at an early stage because some objection is found. Another article (How to Raise a Creative Child. Step One: Back Off) gave another clue about creativity - that training hampers our flexibility: First, can’t practice itself blind us to ways to improve our area of study? Research reveals that the more we practice, the more we become entrenched — trapped in familiar ways of thinking. Expert bridge players struggled more than novices to adapt when the rules were changed; expert accountants were worse than novices at applying a new tax law.