Make Them Learn: With Carrot or Stick?

Feedback is essential for learning. Not only does the feedback need to ensure that learning was achieved (as in testing), but feedback also needs to reinforce the motivation to learn. The age-old questions arises: do we use the carrot or the stick? Which works best, negative or positive reinforcement? Most people have an opinion, but now we have scientific studies of the question. And the answer is, it depends.

For example, three studies showed that adults correct their behavior better in response to negative feedback rather than positive feedback, whereas 8- to 11-year old children respond just the opposite. A follow-up study by Anna van Duijvenvoorde and colleagues in the Netherlands used MRI scans to examine how the brain changes with age and how that relates to feedback-based learning. The subjects were divided into three age groups, 8-9, 11-13, and 18-25. Each subject performed the same learning task and were given positive and negative feedback to improve their performance. After each trial, subjects were shown on a screen an “X” or a “+” to tell them they were wrong or right.

Regardless of the nature of the feedback, young adults learned bdetter than the children. For all three age groups, learning was more effective with positive feedback. Moreover, the decreased learning from negative feedback was conspicuously greater in the youngest age group, while in the young adults, the effect of feedback type was negligible.

Not surprisingly, there were brain scan indicators of differing response to type of feedback. With age, both types of feedback produced a shift toward recruiting more activity in the dorsolateral prefrontal cortex. This part of the cortex was more active after negative feed back in adults but after positive feedback in the 8-9 year-old children. The prefrontal cortex activity was about the same for negative and positive feedback in the 11-13 year olds, suggesting that this is a transition stage in development of learning style and capability.

Take home message? Positive feedback usually works best in young children (that is, after all, how they train seals). Negative feedback works just about as well as positive feedback in young adults. One more point: with the exception of language acquisition, young children are not the superior learners that many people believe.

Source: van Duijvenvoorde, A. C. K. 2008. Evaluating the negative or valuing the positive? Neural mechanisms supporting feedback-based learning across development. J. Neuroscience. 28 (38) 9495-9503.

Negative Emotions and Memory

I have a big section in my memory book on the interference with memory formation caused by negative emotions. I have seen first hand how emotional crises cause the grades of college students to plummet. Whenever a good student suddenly starts making poor grades, I know this student has recently had an emotional trauma. Common problems for college students include trouble making friends, boy/girl problems, parent divorce, homesickness, financial worries―grades invariably suffer.

Recently, I had a reader of this blog challenge my position, pointing out that the most severe form of negative emotions, post-traumatic stress (PTSD), has as its main problem the inability to forget the events that triggered the PTSD. My reader is of course correct. But so also is all the evidence that negative emotions interfere with memory. How do I reconcile these incompatible views?

What is so well-remembered in PTSD are the traumatic events that caused the negative emotions. That is not the same as saying that PTSD patients have exceptional ability to remember other things or learn new things. I contend that their memory for new learning is impaired because of their distressed emotional state. The reason they remember the PTSD events so well is because they rehearse them so often.

All intense situations, even happy ones, tend to be well-remembered because of the intensity of the stimuli and the fact that such situations are repeatedly rehearsed. Rehearsal usually occurs immediately, because of the intensity of stimulation, and is repeated frequently, because the situation had such a big emotional impact. It is not so much the positive or negative aspect of the situation that matters for memory formation, but rather the timing and frequency of rehearsal.

Why do negative emotions interfere with new learning? I haven’t seen formal studies of this question, but what I know about memory allows some useful speculation. First, feelings such as worry, fear, depression, loneliness, and the like, have devastating effects on motivation. Under such conditions, nobody feels much like taking on challenges. Negative feelings also make it hard to pay attention to anything else besides what is causing the emotional distress. Attentiveness is pre-requisite for forming memories of new learning. Negative feelings lead to persistent negative thoughts, and thinking about one thing while trying to memorize another just doesn’t work. Negative feelings also erode confidence and sense of well being, both of which are essential for optimal memory ability. Why confidence and sense of well being are important is unclear, but I suspect they motivate a person to do what it takes to achieve personal goals. In the case of memory ability, it is easier for an up-beat person to take on learning challenges and to do the right things for promoting memory formation.

Internet Is Better for the Brain than Books?

A new brain imaging study showed that going online stimulated larger parts of the brain than the relatively passive activity of reading a novel or non-fiction book.

The science writer, Richard Alleyenne, of the lay article claims that this proves that Internet browsing is better for brain development than reading books. The scientists involved in the research seem to agree. Here are quotes from the article:

It was so stimulating that the authors of the study believe it could actually help people maintain healthier brains into their old age. The study results are encouraging, that emerging computerised technologies may have physiological effects and potential benefits for middle-aged and older adults," said principal investigator Dr Gary Small, a professor at the Semel Institute for Neuroscience and Human Behavior at University of California. Internet searching engages complicated brain activity, which may help exercise and improve brain function." The study, the first of its kind to assess the impact of internet searching on brain performance, is published in the American Journal of Geriatric Psychiatry.

Well, before you tell schools to throw away the textbooks and let the kids browse away, you should know this: when a brain lights up in many places, it means the brain does not know how to deal with all the stimuli. It has not mobilized or focused its neural circuitry to deal with the stimuli efficiently and effectively. In most imaging studies I have read, when a brain knows how to cope with a task, FEWER areas light up. In other words, a brain works best when it can focus its resources. If you want your kids to grow up scatterbrained, put them on the Web. If you want them to develop longer attention spans and improve critical thinking skills, have them read good books. Their brain will thank you.