Psychology graduate students are involved in a host of innovative research projects addressing many aspects of the human brain, body and behavior. Here are some brief profiles of student researchers-how they got started and where their research is going.
For years, researchers have assumed that people can recognize only a handful of "basic" emotions-fear, anger, disgust, happiness, sadness and surprise-based purely on nonverbal facial expressions or body language. But recently, University of British Columbia early-career psychologist Jessica Tracy, PhD, has found evidence of another emotion expression-pride. And she's found that children as young as 4 years old can recognize when adults look proud.
"There's no reason to assume that more complex emotions don't have a specific nonverbal expression, especially if you don't limit it to just the face" says Tracy, who completed the research while a graduate student in social psychology at the University of California, Davis.
She and her colleagues showed 50 children-ages 3 to 7-three pictures: one of a person who looked happy, one of a person who looked surprised and one of a person who looked proud. The pride picture was based on an earlier study Tracy and her colleagues conducted, in which they defined the characteristic proud expression-a small smile, chest expanded, shoulders pulled back and head slightly tilted.
Tracy and her colleagues asked the children to point to the picture in which the person looked proud. They found that the children could identify the correct picture 59 percent of the time-much greater than the 33 percent expected by chance.
The researchers then looked more specifically at each age group. They found that 3-year-old children couldn't identify the pride expression at a rate greater than chance, but 4-year-olds could find it 65 percent of the time.
The research was published in September in the APA journal Emotion (Vol. 5, No. 3, pages 251-257). Tracy and her colleagues have also just finished an as-yet-unpublished cross-cultural study in which they demonstrate that adults in Burkina-Faso recognize the same pride expression as adults in the United States.
A LIAR'S BRAIN LOOKS DIFFERENT
The brains of chronically deceitful people look different from those of trustworthy folk, according to research by third-year University of Southern California graduate student Yaling Yang. She's found that liars have a higher ratio of white matter to gray matter than nonliars have. Gray matter is made up of nerve cell bodies, while white matter contains the connections between those cell bodies.
Yang and her colleagues used the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) and other psychological measures to separate her participants into three groups: 21 normal control participants, 12 participants who had a history of lying and 16 control participants who showed signs of antisocial personality disorder but no history of lying. Then, the researchers used functional magnetic resonance imaging (fMRI) to examine all the participants' prefrontal cortices.
They found that the liars had 22.2 percent more white matter than the normal controls and 25.7 percent more than the antisocial controls. That finding makes sense, Yang says, because, developmentally, white matter is linked to the ability to deceive.
"Kids start to learn to deceive other people at about age 3 and by age 10 they can be pretty good at lying-like adults," she explains. "And those ages, from 3 to 10, are exactly the ages that the white matter in the brain increases by about 60 percent."
Also, she says, children with autism don't see this same increase-the white matter in their brains increases by only about 10 percent during that time. And autistic children lack the ability to understand what other people are thinking-a skill crucial to lying.
Yang's study was published in September in the British Journal of Psychiatry (Vol. 187, No. 4, pages 320-325). Now, she and her colleagues are trying to home in on the particular area of the prefrontal cortex involved in lying. They're running a similar study but separating the prefrontal area into four sections. Yang says that she expects to see the most differences in the orbitofrontal and ventral lateral areas because those areas have been linked to moral judgment and impulsivity control.
HOW CHILDREN LEARN LANGUAGE
If you've ever listened to someone speak a foreign language, you've probably noticed that not only can't you understand what they're saying, you can't even tell where one word ends and another begins. The whole language is just a jumble of sounds.
Young children who are learning their native language face the same issue, says Katherine Graf-Estes, a fifth-year developmental psychology graduate student at the University of Wisconsin-Madison.
Graf-Estes is examining how babies and young children learn to separate out one word from another, how they learn the meanings of words and how the two are linked.
"In the real world, babies are bombarded with words around them all the time," she says. "And it seems like they're actually pretty good at figuring out where the individual words are."
To examine this further, she and her colleagues tested 17-month-old children. They played the children a two-and-a-half minute recording of an artificial language, with words like "teemay" and "doughboo." Then, they showed the children two made-up shapes on a screen, and played a recording of two of the artificial words in order to get the children to associate a word with each shape.
Finally, they showed the children the shapes for a second time, and either played the correct name-the one the shape had been labeled with before-or an incorrect name. If the children had learned the artificial words, Graf-Estes explained, they would be surprised by the incorrect name and would look at that object longer.
The researchers found that children who had listened to the two-and-a-half minute recording later learned the labels for the new objects better than children who hadn't heard the recording-suggesting that they managed to parse out individual words while they listened.
"This seems to be tapping into a really basic ability to find regularities and co-occurances in language," Graf-Estes says. "I expect that in adults learning a language it would work the same way."
People with nonverbal learning disorder have a hard time with visual tasks. Although they have average or above-average intelligence, they find it difficult to work with shapes, copy drawings and do other visual and spatial tasks. Now, research by recent developmental psychology graduate Carmen Rasmussen, PhD, suggests that children with this disability may also find it particularly difficult to remember and recognize faces.
"We know that nonverbal learning disability is characterized by deficits in visuospatial abilities," Rasmussen says. "But how memory is affected hasn't been studied very much."
This disability itself is not yet well understood, according to Rasmussen. In the DSM-IV, it falls under the general learning disabilities category. Some researchers think that it may be related to autism spectrum disorders like Asperger's syndrome.
Rasmussen, who is now a research associate in the pediatrics department at the University of Alberta, tested 14 elementary school children with nonverbal learning disability. She and her colleagues showed the children patterns of dots and pictures of faces, then showed them the same patterns or pictures a few minutes later-along with pictures they hadn't seen before-to see if they could recognize them. The researchers found that most of the children could remember the dot patterns fairly easily, but couldn't remember the faces.
That might be because the children were actually using verbal strategies to remember the dots, Rasmussen explains-doing things like telling themselves the dots looked like a square or a circle. However, verbal strategies wouldn't work for something as complex as a person's face.
Rasmussen, who finished her doctorate last summer, completed her study while a graduate student at the University of Alberta in Edmonton. The study was published in the August issue of the journal Learning Disabilities Research and Practice (Vol. 20, No. 3, pages 137-141). Now, she and her colleagues are working on a follow-up study that will examine whether children with nonverbal learning disability use verbal strategies to remember other pictures. They're testing whether these children find it harder to remember a picture when the name of the object pictured is longer and more complex-for example, whether the children find it harder to remember a picture of a kangaroo than one of a cat.