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.
Recognizing resilience's roots
Many children with gay and lesbian parents face homophobia and discrimination, but study after study has shown them to be as psychologically healthy as children of heterosexual parents, notes Kate Kuvalanka, a fifth-year graduate student in the University of Maryland's family studies program. With a study supported by an American Psychological Foundation Wayne F. Placek research grant, Kuvalanka hopes to discover the roots of their resilience.
This fall, Kuvalanka will begin interviewing about 40 college-age participants who grew up with lesbian mothers. She will discover what sorts of stigma the participants experienced as teenagers and explore what coping methods they used when faced with homophobia.
"There is still much to learn about gay families, but I am predicting that strong social support among family and friends are going to be important for these kids," says Kuvalanka.
The earlier a person with schizophrenic symptoms gets treatment, the better the prognosis, says Rachel Loewy, a sixth-year clinical psychology graduate student at the University of California, Los Angeles (UCLA). But assessing people in the first stages of schizophrenia requires a lengthy in-person interview--a procedure that eats up staff time at hospitals and clinics, she says. So Loewy and her colleagues are developing a two-step screening process to use staff resources more efficiently.
Loewy is refining the first step of such a process: a questionnaire that clinicians can use to sift out those unlikely to develop schizophrenia. Her survey includes 92 questions lifted from questionnaires and diagnostic interviews, such as "sometimes I think that people can read my mind." But she hopes to cut the number of questions in half.
To make the questionnaire shorter and test its efficacy, Loewy will ask 500 people referred to the UCLA Center for Assessment and Prevention of Prodromal States to complete the survey before they head to the second step of the process, a traditional diagnostic interview. She will then compare the results of the survey with those of the interview. Finally, over a period of a year, Loewy will follow up with the patients to determine whether they developed full-blown schizophrenia.
Preliminary data suggests that Loewy's questionnaire correctly rejects five out of 10 participants who would not be identified as prepsychotic by the clinical interview--effectively freeing up 50 percent of staff time currently spent in clinical interviews.
Once she has finished collecting the data, Loewy will use a statistical technique known as item response theory to determine which questions can be eliminated without reducing the test's predictive ability.
Perfecting police lineups
When police ask an eyewitness to identify a suspect, they frequently use a lineup technique in which a photo of the suspect is presented among similar-looking people who are not suspected of committing the crime. However, research by Claremont Graduate University psychology student Aris Karagiorgakis suggests that this strategy can lead witnesses to falsely identify innocent suspects--a finding that echoes past research.
"I found that an innocent suspect is not protected by the method the police currently use," says Karagiorgakis. "This is bad news for the innocent."
Karagiorgakis reached this conclusion by presenting 192 undergraduate students with pictures of six guilty perpetrators, including one who he identified as "Chris the criminal." Two days later, he returned to the classes and presented two kinds of lineups:
Match to appearance (MTA) lineups, constructed of a guilty perpetrator such as Chris or an innocent suspect placed among others who resembled his picture. This is the kind of lineup most police departments use.
Match to description (MTD) lineups, constructed of a guilty perpetrator such as Chris or the innocent suspect and others who were similar not in appearance, but instead by written description. A previous group of students read written descriptions of Chris and the innocent suspect and then selected photos of men for the lineups based on the written description of the suspect.
The students picked the guilty perpetrator from both kinds of lineups equally well. However, when faced with an MTA-constructed lineup of only innocent men, the students tended to pick out the person upon whom the lineup was based--the innocent suspect--instead of figuring out that the guilty party wasn't present. In the MTD condition, students tended to correctly respond that the guilty man was not present.
Such results show that people can unconsciously infer whose likeness the lineup was built around, and that can lead to innocent suspects being falsely identified, says Karagiorgakis. He suspects the participants homed in on the face that had features in common with the other faces in the lineup--a phenomenon known as the "prototype effect."
Unfortunately, police departments generally use the MTA method for constructing lineups, notes Karagiorgakis, who works as a researcher with police in Westminster, Calif. But hopefully, as evidence against MTA accrues, departments may switch over to the MTD method, he says.
How frogs hear
Columbia University neurobiology and behavior graduate student Taffeta Elliott is studying the South African clawed frog because its well-developed auditory system parallels her interest in auditory perception. The amphibian relies almost entirely on sounds to communicate in its muddy environment, says Elliott. When the female frog is ready to mate, she changes her calling from her usual slow-rate of clicking to a faster one. In response, any male frog within hearing distance alerts the female to his presence with a call of his own.
With funding from the National Science Foundation and the National Institute on Deafness and Other Communication Disorders, Elliott is exploring how the male frogs discern between the fertility calls of the females and their usual slow-paced clicking.
To begin, she traced the path of sound from the auditory nerve to the animal's midbrain by using microelectrodes to record the firing of cells along the way. Early in the pathway, cells fire along with each click of the female's call, found Elliott. However, once the signal reached the animal's midbrain, some cells only fired during fast calls while others only fired for slow ones.
She next collected behavioral data from the animals--playing ambiguous female calls to male frogs in a tank. The male tended to respond to any call with more than 160 milliseconds between clicks as if it were the call of an ovulating female, which in the wild average 81 milliseconds between clicks. However, the frogs chose somewhat different boundaries on subsequent trials, suggesting they perceive a fuzzy border between fast and slow calls, says Elliott.
In addition to describing how frogs hear, such research could shed light on the human auditory system, says Elliott.
Knowing how the temporal patterns of sound are coded in the brain will help researchers understand many disorders of language, including dysphasia and dyslexia, she says.