Tag Archives: learning

What Do Preschoolers Learn from Fantastical Picture Books?

April 16, 2014 By in Science Tags: , , , , 5 Comments

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One of the new picture books making the bedtime rounds at our house is How Do Dinosaurs Say Goodnight?, which describes and depicts dinosaurs doing such un-dinosaurly things as tucking themselves into bed or kissing their human mothers good night. The book is whimsical, gorgeously illustrated, and includes a scientific angle, as the genus names of the dinosaurs are included in the pictures. I’m always careful to read these genus names aloud as we look at each picture. But is this book actually teaching my daughter anything about dinosaurs? And does the misinformation get in the way of her learning these facts? A new study suggests that it might.

Picture books that anthropomorphize animals – and even inanimate objects – are the norm rather than the exception. These books are whimsical and fanciful. They depict worlds like our own but different in magical ways that delight children and adults alike. Perhaps these books are more engaging for young children, fostering lifelong reading habits. Perhaps they stimulate a child’s blossoming imagination. Perhaps – although I would argue that the true story of our diverse, teeming planet is more remarkable than talking teddy bears or hippos in swimsuits.

Look at it this way: everything we do is meant to prepare our children for life in this complex and befuddling world. Why, then, do we feed them so much distorted, inaccurate information? How are they supposed to know what is real and what is fantasy? How is my daughter supposed to know that the three-horned dinosaur was called Triceratops but that it never coexisted with humans nor stomped on its hind legs to protest bedtime?

Researchers in Boston and Toronto looked into this issue and recently published their findings in Frontiers in Psychology. The scientists created picture books based on three animals species that are relatively unknown among North American children: cavies, oxpeckers, and handfish. Their study consisted of two separate experiments. For the first experiment, all of the books featured factual illustrations of the animals, but for each animal the authors made one version of the book with realistic text and one version with text that depicted the animals as human-like. Here are two examples:

Lonely cavy seeks companionship and good conversation.

Lonely cavy seeks companionship and good conversation.

Realistic
When the mother cavy wakes up, she usually eats lots of grass and other plants.
Then the mother cavy feeds her baby cavies.
Mother cavy also licks the babies’ fur to keep them clean.
Mother cavy and her babies spend the rest of the day lying in the sun.
At night, they sleep in a small cave.
After they go to sleep, mother cavy’s big ears help her hear noises around her.

Anthropomorphic
“Yum, those grass and plants are delicious!” Mother cavy thinks as she eats her breakfast.
“I will feed some to my baby cavies too!” she says.
The baby cavies love to play in the grass! But they’ve gotten all dirty! “Time for your bath,” Mother cavy says.
Mother cavy and her babies like to spend the afternoon sunbathing.
At night, Mother cavy tucks her babies in to bed in a small cave. “Mom, I’m scared!” says the baby cavy.
“Don’t be afraid,” she says. “I’ll listen for noises with my big ears and keep us safe.”

Children ages 3 to 5 years old were randomly assigned to read the books with either the factual or fantasy text. After children read one of these books with an experimenter, a second experimenter showed them a picture of the real animal described the story and asked the kids questions about it. Do cavies eat grass? Do cavies talk? Some of these questions tested the factual information kids took away from the picture book, while others tested how much the children anthropomorphized the animal. The children who read the books with talking animals were more likely to say those animals really talk than were children who read the versions with factual text. Still, the two groups were roughly equal in the factual information they retained about the animals.

Oxpeckers ready for adventure.

Oxpeckers ready for adventure.

For the second experiment, the researchers again made two versions of picture books for each animal. This time, both versions showed the animals dressed in clothes, sitting at tables, or engaged in other human activities. As before, the researchers made two versions of each book: one with factual text and one that anthropomorphized the animals. The children who read the fully anthropomorphized picture books tended to believe that the animals really engage in human behaviors like speech. These kids also answered fewer factual questions about the animals correctly (compared with the children who read factual text paired with the fantastical pictures).

These findings have two major implications. First, picture books that anthropomorphize animals seem to actually teach children that animals think and behave like humans. In one sense you might say this is good, as it could discourage animal cruelty and abuse. But in another sense, it’s highly unproductive. At the very best, children will have to unlearn all of this nonsense. At worst, they will carry some of this misinformation about the natural world throughout life – probably not as a belief in talking animals, but in the assumptions they make about the thoughts, feelings, and intentions of other species.

The other takeaway is that the whimsical aspects of a picture book may be sabotaging your child’s learning of the real information in these stories, particularly when the illustrations and text both reflect fantasy.  Since children can’t conclusively tell fact from fiction, some may be discounting all information from highly fanciful stories – including incredible-yet-true facts like the chameleon’s mercurial skin tone or the transformation of caterpillar into butterfly. As the authors write in their paper: “if the goal of the picture book interaction is to teach children information about the world, it is best to use books that depict the world in a realistic rather than fantastical manner.” Of course that takes enthusiasm out of the equation. What kid would sit for hours watching videos of real trains when he or she could watch Thomas? Human narrative adds interest, but it also seems to muddle up real learning, at least in preschoolers.

I hate to build an argument against imaginative, fanciful picture books. What am I, Scrooge? But while I love imagination, I don’t love misinformation – particularly scientific misinformation. And while I love magic, I don’t love magical thinking or flawed reasoning about the natural world. I’m not saying you should throw away your copy of Goodnight Moon and all things Sandra Boynton – just keep in mind that wee ones don’t always know real from fanciful or facetious. Talk about these concepts with them. Buy some nonfiction picture books with accurate information about animals and keep them in the lineup. And know that, for all your efforts, they may come away believing that trains talk and bunnies knit . . . at least for now.

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Photo credits:  Mother and child by KatLevPhoto, cropped for use here; cavy by Brent Moore; oxpeckers by Steve Garvie. All used via Creative Commons license

Ganea, P., Canfield, C., Simons Ghafari, K., & Chou, T. (2014). Do cavies talk? The effect of anthropomorphic picture books on children’s knowledge about animals Frontiers in Psychology, 5 DOI: 10.3389/fpsyg.2014.00283

The Slippery Question of Control in OCD

March 27, 2014 By in Mental Illness, Minds, Science Tags: , , , , 4 Comments

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It’s nice to believe that you have control over your environment and your fate – that is until something bad happens that you’d rather not be responsible for. In today’s complex and interconnected world, it can be hard to figure out who or what causes various events to happen and to what degree you had a hand in shaping their outcomes. Yet in order to function, everyone has to create mental representations of causation and control. What happens when I press this button? Did my glib comment upset my friends? If I belch on the first date, will it scare her off?

People often believe they have more control over outcomes (particularly positive outcomes) than they actually do. Psychologists discovered this illusion of control in controlled experiments, but you can witness the same principle in many a living room now that March Madness is upon us. Of course, wearing your lucky underwear or sitting in your go-to La-Z-Boy isn’t going to help your team win the game, and the very idea that it might shows how easily one’s sense of personal control can become inflated. Decades ago, researchers discovered that the illusion of control is not universal. People suffering from depression tend not to fall for this illusion. That fact, along with similar findings from depression, gave rise to the term depressive realism. Two recent studies now suggest that patients with obsessive-compulsive disorder (OCD) may also represent contingency and estimate personal control differently from the norm.

OCD is something of a paradox when it comes to the concept of control. The illness has two characteristic features: obsessions based on fears or regrets that occupy a sufferer’s thoughts and make him or her anxious, and compulsions, or repetitive and unnecessary actions that may or may not relieve the anxiety. For decades, psychiatrists and psychologists have theorized that control lies at the heart of this cycle. Here’s how the NIMH website on OCD describes it (emphasis is mine):

The frequent upsetting thoughts are called obsessions. To try to control them, a person will feel an overwhelming urge to repeat certain rituals or behaviors called compulsions. People with OCD can’t control these obsessions and compulsions. Most of the time, the rituals end up controlling them.

In short, their obsessions cause them distress and they perform compulsions in an effort to regain some sense of control over their thoughts, fears, and anxieties. Yet in some cases, compulsions (like sports fans’ superstitions) seem to indicate an inflated sense of personal control. Based on this conventional model of OCD, you might predict that people with the illness will either underestimate or overestimate their personal control over events. So which did the studies find? In a word: both.

The latest study, which appeared this month in Frontiers in Psychology, used a classic experimental design to study the illusion of control. The authors tested 26 people with OCD and 26 comparison subjects. The subjects were shown an image of an unlit light bulb and told that their goal was to illuminate the light bulb as often as possible. On each trial, they could choose to either press or not press the space bar. After they made their decision, the light bulb either did or did not light up. Their job was to estimate, based on their trial-by-trial experimentation, how much control they had over the light bulb. Here’s the catch: the subjects had absolutely no control over the light bulb, which lit up or remained dark according to a fixed sequence.*

After 40 trials, subjects were asked to rate the degree of control they thought they had over the illumination of the light bulb, ranging from 0 (no control) to 100 (complete control). Estimates of control were consistently higher for the comparison subjects than for the subjects with OCD. In other words, the people with OCD believed they had less control – and since they actually had no control, that means that they were also more accurate than the comparison subjects. As the paper points out, this is a limitation of the study: it can’t tell us whether patients are generally prone to underestimating their control over events or if they’re simply more accurate that comparison subjects. To do that, it would need to have included situations in which subjects actually did have some degree of control over the outcomes.

Why wasn’t the light bulb study designed to distinguish between these alternatives? Because the authors were expecting the opposite result. They had designed their experiment to follow up on a 2008 study that found a heightened illusion of control among people with OCD. The earlier study used a different test. They showed subjects either neutral pictures of household items or disturbing pictures of distorted faces. The experimenters encouraged the subjects to try to control the presentation of images by pressing buttons on a keyboard and asked them to estimate their control over the images three times during the session. However, just like in the light bulb study, the presentation of the images was fixed in advance and could not be affected by the subjects’ button presses.

How can two studies of estimated control in OCD have opposite results? It seems that the devil is in the details. Prior studies with tasks like these have shown that healthy subjects’ control estimates depend on details like the frequency of the preferred outcome and whether the experimenter is physically in the room during testing.  Mental illness throws additional uncertainty into the mix. For example, the disturbing face images in the 2008 study might have made the subjects with OCD anxious, which could have triggered a different cognitive pattern. Still, both findings suggest that control estimation is abnormal for people with OCD, possibly in complex and situation-dependent ways.

These and other studies indicate that decision-making and representations of causality in OCD are altered in interesting and important ways. A better understanding of these differences could help us understand the illness and, in the process, might even shed light on the minor rituals and superstitions that are common to us all. Sadly, like a lucky pair of underwear, it probably won’t help your team get to the Final Four.

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Photo by Olga Reznik on Flickr, used via Creative Commons license

*The experiment also manipulated reinforcement (how often the light bulb lit up) and valence (whether the lit bulb earned them money or the unlit bulb cost them money) across different testing sections, but I don’t go into that here because the manipulations didn’t affect the results.

Gillan CM, Morein-Zamir S, Durieux AM, Fineberg NA, Sahakian BJ, & Robbins TW (2014). Obsessive-compulsive disorder patients have a reduced sense of control on the illusion of control task. Frontiers in Psychology, 5 PMID: 24659974

Perfect Pitch Redux

January 8, 2014 By in Brains, Mental Illness, Science Tags: , , , , , Leave a comment

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I can just hear the advertisement now.

Do you have perfect pitch? Would you like to? Then Depakote might be right for you . . .

Perfect pitch is the ability to name or produce a musical note without a reference note. While most children presumably have the capacity to learn perfect pitch, only one in about ten thousand adults can actually do it. That’s because children must receive extensive musical training as youngsters to develop it. Most adults with perfect pitch began studying music at six years of age or younger. By the time children turn nine, their window to learn perfect pitch has already closed. They may yet blossom into wonderful musicians but they will never be able to count perfect pitch among their talents.

Or might they after all?

Well no, probably not. But a new study, published in Frontiers in Systems Neuroscience, has opened the door to such questions. Its authors tested how young men learned to name notes when they were on or off of a drug called valproate (brand name: Depakote). Valproate is widely used to treat epilepsy and bipolar disorder. It’s part of a class of drugs called histone-deacetylase, or HDAC, inhibitors that fiddle with how DNA is stored and alter how genes are read out and translated into proteins.

The intricacies of how HDAC inhibitors affect gene expression and how those changes reduce seizures and mania are still up in the air. But while some scientists have been working those details out, others have been noticing that HDAC inhibitors help old mice learn new tricks. These drugs allow adult mice to adapt to visual and auditory changes in ways that are only otherwise possible for juvenile mice. In other words, HDAC inhibitors allowed mice to learn things beyond the typical window, or critical period, in which the brain is capable of that specific type of learning.

Judit Gervain, Allan Young, and the other authors of the current study set out to test whether HDAC inhibitors can reopen a learning window in humans as well. They randomly assigned their young male subjects to take valproate for either the first or the second half of the study. (Although I usually get my hackles up about the exclusion of female participants from biomedical studies, I understand their reason for doing so in this case. Valproate can cause severe birth defects. By testing men, the authors could be one hundred percent certain that their participants weren’t pregnant.) The subjects took valproate for one half of the study and a placebo for the other half . . . and of course they weren’t told which was which.

During the first half of the study, they trained twenty-four participants to learn six pitch classes. Instead of teaching them the formal names of these pitches in the twelve-tone musical system, they assigned proper names to each one (e.g., Eric, Rachel, or Francine), indicating that each is the name of a person who only plays one pitch class. The participants received this training online for up to ten minutes daily for seven days. During the second half of the study, eighteen of the same subjects underwent the same training with six new pitch classes and names. At the end of each seven-day training session, they heard the six pitch classes one at a time and, for each, answered the question: “Who played that note?”

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Study results showing better performance at naming tones for participants on valproate in the first half of the experiment. From: Gervain et al, 2013

The results? There was a whopping effect of treatment on performance in the first half of the study. The young men on valproate did significantly better than the men on placebo. That’s pretty cool and amazing. It is particularly impressive and surprising because the participants received very little training. The online training summed to a mere seventy minutes and some of the participants didn’t even complete all seven of the ten-minute sessions.

As cool as the main finding is, there are some odd aspects to the study. As you can see from the figure, the second half of the experiment (after the treatments were switched) doesn’t show the same result as the first. Here, participants on valproate perform no differently from those on placebo. The authors suggest that the training in the first half of the experiment interfered with learning in the second half – a plausible explanation (and one they might have predicted in advance). Still, at this point we can’t tell if we are looking at a case of proactive interference or a failure to replicate results. Only time and future experiments will tell.

There were two other odd aspects of the study that caught my eye. The authors used synthesized piano tones instead of pure tones because the former has additional cues like timbre that help people without perfect pitch complete the task. They also taught the participants to associate each note with the name of the person who supposedly plays it rather than the name of the actual note or some abstract stand-in identifier. Both choices make it easier for the participants to perform well on the task but call into question how similar the participants’ learning is to the specific phenomenon of perfect pitch. Perhaps the subjects on valproate in the first half of the experiment were relying on different cues (e.g., timbre instead of frequency). Likewise, associating proper names of people with notes may help subjects learn precisely because it recruits social processes and networks that people with perfect pitch don’t use for the task. If these social processes don’t have a critical period like perfect pitch judgment does, well then valproate might be boosting a very different kind of learning.

As the authors themselves point out, this small study is merely a “proof-of-concept,” albeit a dramatic one. It is not meant to be the final word on the subject. Still, I am curious to see where this leads. Might valproate’s success with seizures and mania have something to do with its ability to trigger new learning? And if HDAC inhibitors do alter the brain’s ability to learn skills that are typically crystallized by adulthood, how has that affected the millions of adults who have been taking these drugs for years? Yet again, only time and science will tell.

I, for one, will be waiting to hear what they have to say.

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Photo credit: Brandon Giesbrecht on Flickr, used via Creative Commons license

Gervain J, Vines BW, Chen LM, Seo RJ, Hensch TK, Werker JF, & Young AH (2013). Valproate reopens critical-period learning of absolute pitch. Frontiers in Systems Neuroscience, 7 PMID: 24348349

Feeling Invisible Light

February 21, 2013 By in Brains, Minds, Science Tags: , , , , , Leave a comment

7401773382_19963f6a8b_cIn my last post, I wrote about whether we can imagine experiencing a sense that we don’t possess (such as a trout’s sense of magnetic fields). Since then a study has come out that adds a new twist to our little thought experiment. And for that we can thank six trailblazing rats in North Carolina.

Like us, rats see only a sliver of the full electromagnetic spectrum. They can perceive red light with wavelengths as long as about 650 nanometers, but radiation with longer wavelengths (known as infrared, or IR, radiation) is invisible to them. Or it was before a group of researchers at Duke began their experiment. They first trained the rats to indicate with a nose poke where they saw a visible light turned on. Then the researchers mounted an IR detector to each rat’s head and surgically implanted tiny electrodes into the part of its brain that processes tactile sensations from its whiskers.

After these sci-fi surgeries, each rat was trained to do the same light detection task again – only this time it had to detect infrared instead of visible light. Whenever the IR detectors on the animal’s head picked up IR radiation, the electrodes stimulated the tactile whisker-responsive area of its brain. So while the rat’s eyes could not detect the IR lights, a part of its brain was still receiving information about them.

Could they do the new task? Not very well at first. But within a month, these adult rats learned to do the IR detection task quite well. They even developed new strategies to accomplish their new task; as these videos show, they learned to sweep their heads back and forth to detect and localize the infrared sources.

Overall, this study shows us that the adult brain is capable of acquiring a new or expanded sense. But it doesn’t tell us how the rats experienced this new sense. Two details from the study suggest that the rats experienced IR radiation as a tactile sensation. First, the post-surgical rats scratched at their faces when first exposed to IR radiation, just as they might if they initially interpreted the IR-related brain activity as something brushing against their whiskers. Second, when the scientists studied the activity of the touch neurons receiving IR-linked stimulation after extensive IR training, they found that the majority responded to both touch and infrared light. At least to some degree, the senses of touch and of infrared vision were integrated within the individual neurons themselves.

In my last post, I found that I was only able to imagine magnetosensation by analogy to my sense of touch. Using some fancy technology, the scientists at Duke were able to turn this exercise in imagination into a reality. The rats were truly able to experience a new sense by piggybacking on an existing sense. The findings demonstrate the remarkable plasticity of the adult brain – a comforting thought as we all barrel toward our later years – but they also provide us with a glimpse of future possibilities. Someday we might be able to follow up on our thought experiment with an actual experiment. With a little brain surgery, we may someday be able to ‘see’ infrared or ultraviolet light. Or we might just hook ourselves up to a magnificent compass and have a taste (or feel or smell or sight or sound) of magnetosensation after all.

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Photo credit: Novartis AG

ResearchBlogging.org

Thomson EE, Carra R, & Nicolelis MA (2013). Perceiving invisible light through a somatosensory cortical prosthesis. Nature communications, 4 PMID: 23403583

Tooling Around

September 16, 2012 By in Brains, Kids Tags: , , , , , 2 Comments

tools1There was a time when my daughter used her hands exclusively to shovel things into her mouth. Not so anymore. For the last few months, she has been hard at work banging objects together. This simple action is setting the stage for some pretty cool neural development. She is learning to use tools.

Of course it doesn’t look too impressive right now. She might bang a ball with a block and then switch and strike the block with the ball. In one recent playtime she tore a cardboard flap out of her board book and examined it, trying different grips and holding it from different angles as she watched how it cut the air. Then, brandishing her precious flap, she went to work. She wielded it with a scooping motion to lift other flaps in the book, and later, to turn the book pages themselves. After that, she descended on her toy box with the flap. She used it to wipe her blanket, poke her stuffed animal, and finally scrape its face like she was giving it a close shave.

Although my daughter’s fun with flaps may seem aimless, it had an important purpose. Through experimentation and observation, she was learning how two objects can interact and how such interactions are affected by object shape, configuration, and pliability. Such details are so well known to adults that we forget there was anything to learn. But consider how often we use objects against one another. We hammer nails, rake leaves, and staple pages. When using scissors, we must apply different levels of force to cut through paper versus cardboard or fabric. When lifting a pan with a potholder, we must adjust our grip depending on the weight of the pan and whether we are lifting it by the base, side, or handle. We must know the subtle differences between holding a sponge to wash a glass and using a towel to dry it, and we must do each deftly enough that our glassware comes out clean and intact at the end.

There are also countless tools we create on the fly every day. When you use a magazine to nudge your cell phone within reach or flip a light switch with a book because your hands are full, you are devising novel tools to fit your momentary needs. To do this, our brains must store extensive knowledge about the properties of household objects. Through experimentation, like the kind my daughter is doing, we learned to predict how objects will interact and to capitalize on those predictions.

So far I’ve described the value of tools in terms of what they can do: push, pull, gather, polish, lift, etc. But there is another side to tool use that may play a role in my daughter’s little experiments: sensory information gleaned through the tool. As I watched her probe one object with another, I was reminded of research described in Sandra and Matthew Blakeslee’s book The Body Has a Mind of Its Own. The book discussed neurons in the parietal cortex that are tuned to the sight or feel of objects near a particular body part. For example, cells representing your right hand would fire if something touched your right hand, if you saw an object near your right hand, or both. Neuroscientists have discovered that experience using a tool can change the properties of these cells in monkeys (and therefore likely in us as well). They found that if monkeys used a rake to gather goodies otherwise beyond their reach, the parietal neurons that had responded to objects around the hand now fired for items located anywhere along both the hand and the rake it held. In a sense, object manipulation can temporarily extend certain neural body representations to include the tools we wield. The Blakeslees suggest that this may be how a blind person learns to perceive the contour of items encountered at the tip of his cane. In effect, the cane and the hand are one.

For now, our house is filled with smashing, scraping, banging and bending as our baby descends on toys and her parents’ belongings alike. In the midst of such havoc, it’s good to know that the destruction is part of a crucial learning process. And someday, once it slows down, I can buy her a new board book with all the flaps intact.

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Photo credit: zzpza

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