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JoVE Science Education

A video library dedicated to teaching the practice and theory of scientific experiments through engaging and easy-to-understand visual demonstrations.

Education

Habituation: Studying Infants Before They Can Talk

Source: Laboratories of Nicholaus Noles, Judith Danovitch, and Cara Cashon&#8212;University of Louisville
Infants are one of the purest sources of information about human thinking and learning, because they&#8217;ve had very few life experiences. Thus, researchers are interested in gathering data from infants, but as participants in experimental research, they are a challenging group to study. Unlike older children and adults, young infants are unable to reliably speak, understand speech, or even move and control their own bodies. Eating, sleeping, and looking around are the only activities babies can perform reliably. Given these limitations, researchers have developed clever techniques for exploring infants&#8217; thoughts. One of the most popular methods makes use of a characteristic of attention called habituation.
Like adults, infants prefer to pay attention to new and interesting things. If they are left in the same environment, over time they become accustomed to their surroundings and pay less attention to them. This process is called habituation. However, the moment something new happens, infants are waiting and ready to pay attention again. This reengagement of attention following habituation is referred to as dishabituation. Scientists can use these characteristic changes in attention as a tool for studying the thinking and learning of young infants. This method involves initially presenting stimuli to infants until they are habituated, and then presenting them with different kinds of stimuli to see if they dishabituate, i.e., notice a change. By carefully choosing the stimuli shown to the infants, researchers can learn a great deal about how infants think and learn.
This experiment demonstrates how habituation can be used to study infant shape discrimination.

Source: Laboratories of Nicholaus Noles, Judith Danovitch, and Cara Cashon&#8212;University of Louisville
Infants are one of the purest sources of ...

Using Your Head: Measuring Infants' Rational Imitation of Actions

Source: Laboratories of Judith Danovitch and Nicholaus Noles&#8212;University of Louisville
One of the main challenges of infancy is to learn how to achieve one&#8217;s goals in the world, whether they are to pick up a toy or to express desires to another person, and one of the most powerful tools in this learning process is imitation. However, imitation is not always as simple as copying other people&#8217;s actions; it is also necessary to realize that goals and intentions guide behavior. The world is a complicated place, and the actions that babies imitate are not perfectly presented. For example, consider a baby watching their father drinking from a plastic water bottle. As he picks up the bottle, he accidentally drops it on the floor. He picks it up and dusts it off, before turning the cap and taking a drink. If the baby wants to drink from the bottle on their own, they have to decode this complex set of events and determine which actions are related to their goal. Do they have to drop it and dust it off, or can they simply turn the cap and take a drink?
One way to solve this problem is to view many examples of the same behavior, but some behaviors are rare or different each time they are performed. Thus, it is beneficial for infants to think more about the person they are imitating and less about the specific situation they are observing. If infants assume that others are rational and have goals they are efficiently pursuing, then they can observe a complex event and separate the goal-oriented actions from actions that are incidental or unrelated to their goals. Analyzing the reasons underlying a person&#8217;s behavior allows infants to decide whether it makes sense to imitate that person&#8217;s exact actions or to do things in a simpler or more effective way.
This experiment demonstrates how to measure infant&#8217;s rational imitation of an actor using the methods developed by Meltzoff1 and Gergely, Bekkering, and Kiraly.2

Using Your Head: Measuring Infants&#039; Rational Imitation of Actions

Source: Laboratories of Judith Danovitch and Nicholaus Noles&#8212;University of Louisville
One of the main challenges of infancy is to learn how to ...

The Rouge Test: Searching for a Sense of Self

Source: Laboratories of Nicholaus Noles and Judith Danovitch&#8212;University of Louisville
Humans are different from other animals in many ways, but one of the abilities that sets humans apart is their advanced ability to understand other people and simulate their thoughts and feelings, even when the thoughts and feelings do not align with their own. In scientific terms, these abilities are referred to as theory of mind, and this understanding is necessary for activities like giving compliments, working in groups, asking for favors, and telling white lies.
Humans are not born with a fully developed theory of mind. An individual&#8217;s understanding that they are separate from other people and that they have different desires and knowledge requires an established sense of self. Thus, developing self-recognition and self-awareness are some of the initial steps on the path to developing a mature theory of mind. Studying a child&#8217;s emerging sense of self is complicated, because children&#8217;s conceptual development exceeds their mastery of language. To solve this problem, researchers borrowed methods used to detect self-recognition in animals and applied them to young children. Thus, with a mirror and a bit of make-up, the rouge task was born. 
This video demonstrates how researchers assess self-awareness in children at different ages.

Source: Laboratories of Nicholaus Noles and Judith Danovitch&#8212;University of Louisville
Humans are different from other animals in many ways, but one ...

Numerical Cognition: More or Less

Source: Laboratories of Nicholaus Noles and Judith Danovitch&#8212;University of Louisville
One of the goals of the modern education system is to teach children mathematical literacy. They are taught to add, subtract, multiply, and divide, and this base knowledge is used to support learning about geometry, algebra, calculus, physics, and statistics. School-aged children usually acquire these skills in formal educational settings, but the foundation of mathematical understanding is developed much earlier in life.
As infants, humans begin to form the rough representations that allow them to make judgments about number, and perhaps the first numerical concept that humans develop is the idea of less versus more. However, probing these concepts can be challenging, because even if babies have some understanding of number, they have very few ways of showing off what they know. What they can do is crawl, eat, cry, and sleep. Thus, researchers developed a task using this limited set of responses to investigate whether babies can mentally represent number.
This experiment demonstrates how researchers can creatively use food to study concepts of numerical cognition in infants using the method by Feigenson, Carey, and Hauser.1

Investigating Numerical Cognition More/Less in Infants

Source: Laboratories of Nicholaus Noles and Judith Danovitch&#8212;University of Louisville
One of the goals of the modern education system is to teach ...

Mutual Exclusivity: How Children Learn the Meanings of Words

Source: Laboratories of Nicholaus Noles and Judith Danovitch&#8212;University of Louisville
Humans are different from other animals in many ways, but perhaps the most important differentiating factor is their ability to use language. Other animals can communicate and even understand and use language in limited ways, but trying to teach human language to a chimp or a dog takes a great deal of time and effort. In contrast, young humans acquire their native language easily, and they learn linguistic rules without explicit instruction, which is an accomplishment that even the smartest animals cannot match.&#160;
One advantage young humans have over animals is that the human brain is especially adapted to learn new words. With only a few exposures, young children can learn new words and remember them. Perhaps more impressively, children can use what they already know to guide their future learning. For example, children treat objects as if they have only one label. So, if a child has learned the word hammer, they won&#8217;t assume an unfamiliar tool has the same name. This is the principle of mutual exclusivity.1-2
This video demonstrates children&#8217;s ability to use mutual exclusivity to match words to objects in their environment.

Source: Laboratories of Nicholaus Noles and Judith Danovitch&#8212;University of Louisville
Humans are different from other animals in many ways, but ...

How Children Solve Problems Using Causal Reasoning

Source: Laboratories of Judith Danovitch and Nicholaus Noles&#8212;University of Louisville
Imagine a young child hears an adult say, &#8220;I want to watch the news,&#8221; then watches the adult press a button on the remote control. A moment later, the television screen turns on. The next day, the child wants to turn on the television screen to watch cartoons. How does the child know what to do? Is it enough to say, &#8220;I want to watch cartoons,&#8221; or is pushing the button on the remote control necessary, too? Solving this problem requires children to use the information they observed (i.e., the adult&#8217;s behaviors) to come up with a solution. In their daily lives, children encounter many situations where they need to decode cause-and-effect from complex or ambiguous observations in order to accomplish a goal.
In order to examine children&#8217;s capacity for causal reasoning, psychologists set up tasks using causal scenarios to observe how children draw conclusions and test new hypotheses about the relationships between different types of objects. In these tasks, children are shown interactions involving individual objects or sets of objects. Then, they are asked to identify and use the links between the causes and the effects to solve a problem.
This video demonstrates how to measure children&#8217;s causal reasoning about novel objects based on the methods developed by Gopnik and Sobel1 and Gopnik, Sobel, Schulz, and Glymour.2

Source: Laboratories of Judith Danovitch and Nicholaus Noles&#8212;University of Louisville
Imagine a young child hears an adult say, &#8220;I want to ...

Metacognitive Development: How Children Estimate Their Memory

Source: Laboratories of Judith Danovitch and Nicholaus Noles&#8212;University of Louisville
Human memory is fallible, and people often cannot accurately recall what they have seen or heard. Adults are aware of their limited memory capacity, so they use strategies, such as rehearsal and mnemonic devices, to improve their recall of important information. Because adults understand the limits of memory, they know it makes more sense to write down the items on their shopping list rather than to try to remember the items when they get to the store. This ability to think about one&#8217;s own memory is called metamemory. Metamemory is one component of a broader set of cognitive processes that allow humans to think about their own knowledge and thinking, which is called metacognition.
Although young children understand that people have thoughts and a limited amount of knowledge, they often have trouble acknowledging the limits of their own knowledge and cognitive skills. Children&#8217;s ability to accurately estimate their own memory capacity and abilities improves over the elementary school years. One common way of measuring metamemory and its development is by giving children an opportunity to predict how well they can remember something, and then observing how well their prediction matches their actual recall.
This experiment demonstrates how to measure children&#8217;s metamemory based on the methods developed by Shin, Bjorklund, and Beck.1

Source: Laboratories of Judith Danovitch and Nicholaus Noles&#8212;University of Louisville
Human memory is fallible, and people often cannot accurately ...

Executive Function and the Dimensional Change Card Sort Task

Source: Laboratories of Nicholaus Noles and Judith Danovitch&#8212;University of Louisville
Infants are born with amazing cognitive resources at their disposal, but they don&#8217;t know how to use them effectively. In order to harness the power of their brains, humans must develop high-level cognitive processes that manage basic brain functions. These processes make up what psychologists refer to as executive function. Executive function is a key factor in many self-regulatory behaviors, including forming plans to solve problems, negotiating between desires and actions, and directing attention. For example, a child must use several executive processes to stop playing with toys and start cleaning their room. These processes include inhibition (to stop what they&#8217;re doing), planning (to determine what actions need to be performed to clean the room), and attentional control (to stay on task until the cleaning is done). A breakdown of executive function during any of these steps would lead to the room remaining dirty.
Developing executive function is one of the key challenges faced by children as they mature. Some elements of executive function can only be mastered with practice, and brain areas linked to executive function, specifically the prefrontal cortex, develop slowly throughout development, continuing to grow and organize until an individual reaches their twenties. Early demonstrations of executive function have been linked to self-control and behavioral outcomes in children, as well as successes later in life. Relatedly, executive function is impaired in children diagnosed with attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorders.
This experiment demonstrates how to assess executive function in children using the Dimensional Change Card Sort Task, developed by Dr. Philip Zelazo and colleagues.1

Dimensional Change Card Sort Task and Executive Function in Children

Source: Laboratories of Nicholaus Noles and Judith Danovitch&#8212;University of Louisville
Infants are born with amazing cognitive resources at their ...

Categories and Inductive Inferences

Source: Laboratories of Nicholaus Noles and Judith Danovitch&#8212;University of Louisville
It might be possible for the human brain to keep track of each individual person, place, or thing encountered, but that would be a very inefficient use of time and cognitive resources. Instead, humans develop categories. Categories are mental representations of real things that can be used for a variety of purposes. For example, individuals can use the perceptual features of animals to place them into a given category. So, upon seeing a furry, four-legged, tail-wagging, barking animal, a person can determine that it is a dog. This is one of many examples where people use perceptual similarity to fit new experiences into their existing mental representations.
However, category membership is much more than skin deep, especially for representations of animals. Frank Keil demonstrated this by using a simple, yet powerful technique that focused on the differences between natural kinds and artifacts. Natural kinds include animals and other living things, while artifacts consist largely of nonliving things, such as tables or gold bricks. In his study, Keil told children stories about natural kinds and artifacts that underwent transformations causing them to cross categorical boundaries. For example, he described a step-by-step process by which a raccoon was transformed into a creature that resembled a skunk in every way. At the end of the story, the raccoon was black with a white stripe, and it had implanted glands that made it smell like a skunk, too. He asked the children to determine whether the resulting animal was a raccoon or a skunk. He used a similar method to describe the transformation of a tire-an artifact-into a shoe. Children&#39;s responses revealed interesting developmental changes into how people think about artifacts and natural kinds.
This video demonstrates Frank Keil&#39;s transformation study.1

How Children Categorize Objects and Make Inductive Inferences

Source: Laboratories of Nicholaus Noles and Judith Danovitch&#8212;University of Louisville
It might be possible for the human brain to keep track of each ...

The Costs and Benefits of Natural Pedagogy

Source: Laboratories of Nicholaus Noles, Judith Danovitch, and Asheley Landrum&#8212;University of Louisville
Children have many tools they use over the course of development to learn from adults. Perhaps the earliest tool is imitation, simply copying what they see an adult do or say. However, children actually learn much more effectively than one might expect if they were only imitating. This is because, when it comes to learning and teaching, children and adults have a special relationship. Children treat adults as if they are helpful and knowledgeable teachers, and adults teach children information in a manner that is usually efficient and effective. Through these interactions, children can learn much better than if they were simply using trial-and-error or copying adults exactly. This way of interacting is referred to as natural pedagogy, and it is one of the reasons that young humans are gifted learners.
One of the most impressive aspects of natural pedagogy is that no one teaches adults how to be good teachers, and children treat adults as teachers without having to be trained to do so. However, natural pedagogy also entails costs. Children are curious and intrinsically motivated to explore, so children do some of their best learning when given opportunities to learn and explore on their own. Thus, the result of natural pedagogy is that children learn information taught to them very effectively, but explicit teaching restricts their curious, exploratory behaviors. There is a tradeoff between efficient learning and self-driven exploration.
This video demonstrates the method by which Elizabeth Bonawitz, Patrick Shafto, and colleagues1 showed the effects of natural pedagogy on young learners.

Investigating the Benefits and Limitations of Natural Pedagogy

Source: Laboratories of Nicholaus Noles, Judith Danovitch, and Asheley Landrum&#8212;University of Louisville
Children have many tools they use over the ...

Piaget's Conservation Task and the Influence of Task Demands

Source: Laboratories of Judith Danovitch and Nicholaus Noles&#8212;University of Louisville
Jean Piaget was a pioneer in the field of developmental psychology, and his theory of cognitive development is one of the most well-known psychological theories. At the heart of Piaget&#8217;s theory is the idea that children&#8217;s ways of thinking change over the course of childhood. Piaget provided evidence for these changes by comparing how children of different ages responded to questions and problems that he designed.
Piaget believed that at age 5, children lack mental operators or logical rules, which underlie the ability to reason about relationships between sets of properties. This characteristic defined what he called the preoperational stage of cognitive development. One of Piaget&#8217;s classic measures of children&#8217;s ability to use mental operations is his conservation task. In this task, children are shown two identical objects or sets of objects. Children are first shown that the objects are the same on one key property (number, size, volume, etc.). Then, one of the objects is modified so it appears different than the other one (e.g., it is now longer, wider, or taller), but the key property remains the same. Following this transformation, children are asked to judge if the two objects or sets of objects are now the same or different with respect to the original key property.
Piaget reported that children in the preoperational stage (approximately ages 2-7) typically judged the objects to be different after the transformation, even though the key property had not changed. He attributed children&#8217;s incorrect responses to their excessive focus on the change, rather than on the fact that the key property remained the same. However, over the years, researchers have argued that Piaget&#8217;s conservation task is an invalid measure of children&#8217;s reasoning skills. These critics have suggested that children&#8217;s poor performance is due to task demands, such as assumptions about the experimenter&#8217;s goals and expectations when the question about the key property is repeated.
This video demonstrates how to conduct Piaget&#8217;s classic conservation task,1&#8211;2 and how a small modification in the task design can dramatically change children&#8217;s accuracy (based on the methods developed by McGarrigle and Donaldson3).

Piaget&#039;s Conservation Task and the Influence of Task Demands

Source: Laboratories of Judith Danovitch and Nicholaus Noles&#8212;University of Louisville
Jean Piaget was a pioneer in the field of developmental ...

Children's Reliance on Artist Intentions When Identifying Pictures

Source: Laboratories of Judith Danovitch and Nicholaus Noles&#8212;University of Louisville
Children are not the best artists. Sometimes it&#8217;s easy to pick out the characteristic triangular head, whiskers, and tail of a cat, but children often describe elaborate scenarios that they depict as a beautifully unrecognizable mess. Thus, given children&#8217;s questionable artistic talent, how do they know what their drawings, and the drawings of others, represent? One way children identify pictures is by relying on resemblance. If it looks like a cat, then it&#8217;s a cat. However, some pictures do not clearly resemble any real object. In this situation, children must use other means to figure out what the picture represents, including their understanding of what the person who created the picture intended it to represent.
By their first birthday, children are sensitive to the intentions of other people. They know that people&#8217;s actions are driven by their goals, and they can infer a person&#8217;s intentions even if the goal-directed action is not successful (e.g., they understand a person struggling to turn a lid intends to open a jar, even if they never see them succeed in opening it). By about age 3, children can use this understanding of intention to guide their interpretation of drawings and other pictorial representations. They apply this understanding both to identifying their own drawings, and to interpreting drawings created by another person.
This experiment demonstrates how to measure children&#8217;s use of intention to interpret otherwise ambiguous pictures based on the methods developed by Bloom and Markson.1

Children&#039;s Reliance on Artist Intentions When Identifying Pictures

Source: Laboratories of Judith Danovitch and Nicholaus Noles&#8212;University of Louisville
Children are not the best artists. Sometimes it&#8217;s easy ...

Measuring Children's Trust in Testimony

Source: Laboratories of Judith Danovitch and Nicholaus Noles&#8212;University of Louisville
How does a person learn about the world around them? One way is through direct observation and exploration. However, not every piece of information can be observed firsthand. Instead, a person must often rely on other people as information sources. This is particularly true for children who have so many questions about the world around them, yet have limited means of accessing the answers. Thus, children must rely on other people to provide answers to their questions.
There is a popular viewpoint that children are gullible and that they believe everything they hear. However, recent research has shown this is not the case. Children as young as age 3 evaluate what other people say and show selective trust in other people&#8217;s testimony. Children pay attention to and use their knowledge about an individual&#8217;s prior behavior and characteristics to judge whether that individual is a trustworthy informational source. &#160;
This video demonstrates how to measure children&#8217;s trust in testimony based on methods developed by Birch, Vauthier, and Bloom1 and Koenig, Clement, and Harris.2&#160;

Measuring Children&#039;s Trust in Testimony

Source: Laboratories of Judith Danovitch and Nicholaus Noles&#8212;University of Louisville
How does a person learn about the world around them? One way ...

Are You Smart or Hardworking? How Praise Influences Children's Motivation

Source: Laboratories of Judith Danovitch and Nicholaus Noles&#8212;University of Louisville
Imagine teaching two children how to skate. It is a hard task for both of them, and they fall down frequently. After falling down for the first time, one child says that skating is too hard and wants to go home. The other child seems to enjoy the challenge and eagerly gets back up after falling down each time. Why do the children have such different attitudes about the same task? One reason may be that they have different mindsets or beliefs about the nature of their ability.
According to psychologist Carol Dweck, some people have a fixed mindset, and some people have a growth mindset. People with a fixed mindset believe that intelligence or abilities are fixed and cannot change. When these people face a challenge, like learning how to skate, they tend to believe that if a new skill does not come easily, then they are simply no good at it. They do not see their skills as capable of changing, and thus they decide that it&#8217;s useless to continue trying. People with a growth mindset have the opposite attitude. They believe that abilities can be developed through hard work, and they continue trying to improve even if they do not initially succeed.
How do these different mindsets develop? One factor that influences children&#8217;s persistence and motivation to succeed is the way their success is described by other people. Specifically, the kind of praise children receive from adults, such as parents and teachers, can have a powerful effect on their subsequent motivation to perform a challenging task.
This video demonstrates how to measure the effect of praise on children&#8217;s motivation based on the methods developed by Mueller and Dweck.1

Investigating How Praises Influence Children&#039;s Motivation

Source: Laboratories of Judith Danovitch and Nicholaus Noles&#8212;University of Louisville
Imagine teaching two children how to skate. It is a hard task ...

Memory Development: Demonstrating How Repeated Questioning Leads to False Memories

Source: Laboratories of Judith Danovitch and Nicholaus Noles&#8212;University of Louisville
A person is defined as a unique individual based on the people and events they encounter in their lives. Thus, creating, storing, and recalling memories are essential elements of the human experience. However, memory, as adults experience it, takes time to develop. Although young children can learn facts and remember details of their lives from moment-to-moment and day-to-day, they do not create autobiographical memories or detailed memories of events that happen in their lives until age 3 or older.
Even after age 3, children&#8217;s memories differ from those of adults in important ways. Children are less effective at evaluating their own memories than adults, which makes it difficult for them to determine, for example, whether or not their memories are accurate. False memories are a problem for both children and adults, as it is quite easy to create a false memory with a poorly-worded question or a story repeated over and over. However, young children are more susceptible to creating false memories than either older children or adults.
This video demonstrates children&#8217;s vulnerability to false memories using a method developed by Steven Ceci and his collaborators.1-2

Demonstrating How Repeated Questioning Leads to False Memories

Source: Laboratories of Judith Danovitch and Nicholaus Noles&#8212;University of Louisville
A person is defined as a unique individual based on the people ...

Science Education - Psychology

Developmental Psychology