Archive for June 2008
Past, Present, and Promise (Video 1)
Past, Present, and Promise is the first program in the DISCOVERING PSYCHOLOGY series. It provides an introduction to and overview of psychology, from its origins in the nineteenth century to current study of the brain’s biochemistry. You’ll explore the development of psychology in general and some of the paths scientists take to determine relationships among the mind, the brain, and behavior.
Psychology is defined as the scientific study of the behavior of individuals and their mental processes. Like many sciences, psychology has evolved with technology, giving doctors and researchers new tools to measure human behavior and analyze its causes.
In this program, Dr. Mahzarin Banaji from Yale University uses the Implicit Association Test (IAT) to measure how quickly positive or negative values are associated with white or black faces. Her subjects are shown a series of words and pictures and instructed to respond immediately by pushing a button to indicate their most automatic, reflex-like reactions. For example, they may be told to press a button in their right hand if the automatic association is good and to press a button in their left hand if the association is bad. The speed with which the subjects respond is an important element of the experiment because these quick, unconscious connections can reveal biases that differ from conscious beliefs.
The IAT results are matched against functional Magnetic Resonance Imaging (fMRI) data to track activity in the amygdala, the region of the brain that responds to fearful or negative images. By correlating data on the buttons subjects pushed with fMRI information about activity in the amygdala, Dr. Banaji and her colleagues have found some interesting results. The majority of the white American respondents showed an unconscious association of white with good and black with bad, while the African American respondents showed mixed results. Half more quickly associated black with good, and the other half associated white with good.
Tracking brain activity in controlled experiments reveals not only the region of the brain at work, but also the power of images and messages in our culture on the subconscious human psyche, bringing psychologists one step closer to understanding human behavior. Read the rest of this entry »
The Human Brain
Your brain can be considered the most complex organ in your body and the centerpiece of your nervous system. Although your brain works as a unified whole, neuroscientists can identify areas within it that perform specific functions. Your brain is organized into three interconnected layers: the central core, limbic system, and cerebral cortex, all of which contain structures that regulate everyday life. Explore the human brain and its role in regulating your life. |
History of Psychology
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Understanding Research (Video 2)
Understanding Research is the second program in the DISCOVERING PSYCHOLOGY series. This program examines how we know what we know. You’ll explore the scientific method, the distinction between fact and theory, and the different ways in which data are collected and applied, both in labs and in real-world settings.
Research often begins with a question. Traditionally, answers have been found in lab experiments, surveys, test groups, and interviews.
This program provides an example of research in a field setting. Psychologist Dr. Christina Maslach of the University of California at Berkeley studies job burnout, what causes it, and what can be done to prevent it. Instead of using traditional lab settings, Dr. Maslach conducts her research where the burnout is happening, in the workplace, using a real-world setting as a lab.
By taking this “fly-on-the-wall” approach, Dr. Maslach studies stress as it occurs, relying on subjects’ live experiences rather than just their memories or perceptions of past experiences. In this case, she has developed a scale to measure job burnout and a scale to measure the health of the workplace environment. Scientific methods to ensure accuracy are part of her approach. She collects data from carefully controlled measurements and observations, and the research process is methodical. The experiment can then be reproduced and the data tested by other researchers. By sharing data through publishing results, psychologists provide new understandings and new tools, as well as fodder for new questions and debates.
Through this consistent, long-term work, Dr. Maslach’s research has shed light not only on individual employees’ behavior, but also on the behavior of an entire organization. The application of this research helps individuals develop mechanisms for coping with stress, and assists organizations in evaluating the health and effectiveness of the workplace.
The Behaving Brain (Video 3)
The Behaving Brain is the third program in the DISCOVERING PSYCHOLOGY series. This program looks at the structure and composition of the human brain: how neurons function, how information is collected and transmitted, and how chemical reactions relate to thought and behavior.
The human brain is an extraordinarily complex organ made up of different regions and parts, each with its own function. Chemical molecules and electrical impulses constantly flow between regions of the brain, sending signals and messages to other parts of the brain and body. Much like an orchestra, brain functioning depends on many individual parts working together.
One example highlighted in this program is the brain’s role in our ability to remember. Psychologist Dr. Mieke Verfaellie studies the causes and effects of amnesia at the Memory Disorders Research Center in Boston. Her research draws on evidence of damage to the hippocampal region of the brain, the area responsible for laying down new memories.
Contrary to popular opinion, amnesia doesn’t result in the loss of all memory or identity. Amnesia affects our short-term, or anteograde memory, and our ability to learn and retain new information. What’s interesting and often surprising in amnesia cases is that other regions of the brain continue to function normally, such as long-term memory. But damage to even one area, such as short-term memory, can dramatically affect our ability to navigate through daily life.
Neuroscientists are learning from abnormal brain functioning, such as amnesia, to identify normal brain patterns. For instance, the interplay of brain regions and their role in thoughts, understanding, and behavior are now better understood.
For a more detailed breakdown of the human brain, go to the Brain Exploration feature of this site.
Dr. Verfaellie contributed to an article about memory distortions in amnesic patients, published in MIT’s Journal of Cognitive Neuroscience, “When True Recognition Suppresses False Recognition: Evidence from Amnesic Patients.” http://mitpress.mit.edu/journals/JOCN/jcn10602.pdf.
The Responsive Brain (Video 4)
T
he Responsive Brain is the fourth program in the DISCOVERING PSYCHOLOGY series. This program explores how the brain alters its structure and functioning in response to social situations. You’ll learn about the impact of different stimuli on human and animal brains, from the effect of human touch on premature babies to the effect of social status on the health of baboons.
Dr. Russell Fernald is a neuroethologist at Stanford University. Neuroethology integrates brain science with the study of behavior in natural habitats. The goal is to illustrate the interaction among brain, behavior, and environment. Dr. Fernald’s long-term work focuses on the African cichlid fish and how its social system regulates not only brain structures, but also bodily functions.
When a male cichlid fish recognizes an opportunity to become the dominant male, his body turns bright colors. The male fish then chases and attacks other male cichlid fish in an attempt to dominate and defend his territory. The physiological color change results from a response in the hypothalamus in the brain. In the cichlid fish, the signaling peptide cells grow eight times larger, sending the brain eight times the signal. The result is an enlargement of the fish gonads, physiologically preparing the fish to spawn with females.
When the cichlid fish loses control of the territory, he loses his bright coloring. Some fish, however, will then go into hiding, turn on the color signals of dominance, and pretend that they are still dominant for a period lasting up to three weeks.
The human brain also contains the hypothalamus. Neuroethologists hypothesize that behavioral responses parallel to those cichlid fish take place in humans, beginning at puberty. Dr. Fernald’s research illustrates one example of how animal and human brains receive and translate signals from the social environment, resulting in physiological change.
The Developing Child (Video 5)
The Developing Child is the fifth program in the DISCOVERING PSYCHOLOGY series. This program introduces examples of cognitive, perceptual, and behavioral development in children. You’ll explore the roles of heredity and environment in child development, and children’s incremental understanding of such phenomena as object permanence, symbolic reasoning, and perception of visual depth.
One of the most distinctive human characteristics is the ability to understand and use symbols. We have a variety of symbol systems in our everyday lives. We use language, we read, we use pictures, and we understand computer programs. We’re not born with this ability, so what I’m studying are the earliest forms of symbolic reasoning that a child understands, and when that cognitive ability to reason develops.
Specifically, I’m concerned with a child’s understanding of a scale model, a symbol, that represents a larger space. When the child sees the scale model of a miniature playroom, does the child understand that this little playroom represents a bigger room? And when does a child acquire symbolic understanding? The interesting feature of this research is that we see an abrupt change between ages two-and-a-half and three in a child’s ability to understand scale models. When we experiment with scale models of playrooms, the two-and-a-half-year-old doesn’t understand the relationship between the symbolic room and the actual room, and instead treats it as a separate object. The three-year-old, on the other hand, understands immediately that the model is a symbol for an actual room.
In becoming symbolic creatures, we learn to think abstractly. At age three, children acquire the ability to think about things in two different ways at the same time: as both an object and a symbol for something else. Acquiring symbolic understanding is an important milestone in the cognitive development that helps us figure out how the world operates. Later in life, for example, we use it to read maps and understand languages.
This research helps us appreciate the complexity of human thought in young children. The clearer our knowledge of what children know, the better we can work with them as educators and as parents. Read the rest of this entry »
Language Development (Video 6)
Language Development is the sixth program in the DISCOVERING PSYCHOLOGY series. This program outlines the development of language in children. It highlights linguist Noam Chomsky’s theories about the human brain’s predisposition to understand language, and then profiles three scientists working on aspects of psycholinguistics.
One of our main concerns as psycholinguists is figuring out the strategies that children use to discover the grammar of their languages. If you ask ordinary parents how their child learned to talk, they would probably say, “He just imitated. What’s the problem?” Well, one problem is that if you listen to what children say, they often say things they couldn’t have imitated. So a child might say something like “I breaked the glass” or “I falled down.”
Adults don’t say things like “breaked” and “falled,” but children do. These errors are to us the best evidence that the child is doing something creative. The child is in fact working out the structure of the grammar. When you hear a child saying things like “breaked” and “falled,” this means that the child has worked out the pattern for forming the past tense in English. English doesn’t always follow that pattern, but the child has discovered a pattern.
All through the years of language learning, the child is struggling between two opposite problems. On the one hand, he or she wants to adapt language, a particular language, to the natural patterns of thought. On the other hand, the child has to accommodate to the particular grammar of that language. The result, of course, is our adult linguistic capabilities. But along the way, if you look carefully, you can see the interplay between these two factors.
Language is perhaps the most complex cognitive product we have. It’s something that all human beings acquire within the first few years of life, regardless of the circumstances in which they grow up, and to a great extent regardless even of their intelligence. Language reflects something about the basic nature of the human mind. The fact that language is universally so patterned, and that it universally follows such stages of development in its acquisition by children, raises deep questions about the organization of knowledge.
Sensation and Perception (Video 7)
Sensation and Perception is the seventh program in the DISCOVERING PSYCHOLOGY series. This program unravels the complex process of how we see. You’ll learn about visual illusions and what causes them, the biology of perception, the visual pathway, and how the human brain processes information during perception.
Dr. David Hubel explains how cellular structures in the nervous system create the visual pathway between eyesight and brain processing.
In order to understand what we mean by pathway, you need to understand that cells are clustered in the nervous system. They’re aggregated into groups the size of a grain of rice or a marble. One region is connected to another by cables.
So in the case of the visual pathway, you start with the retina where rods and cones are connected by cells. The output is the optic nerve, which contains a million fibers. They end up in one of two regions in the brain, and they connect to other regions, or to the many regions in the cortex. This whole trail is the pathway.
Our studies of single cells tell us that the pathway consists of at least three separate sub-pathways, each with a specific role: one is concerned with color, a second, with form, and a third with movement and depth. If we record any individual cell, depending on the channel, the cell will only respond to one of these three areas.
I want to see how individual cells work when we perceive. We’ve only studied a couple of the visual areas intensely, and there seem to be 18 to 24 different visual areas in the occipital lobe at the back of the brain. Most of our work is on the primary visual cortex, just the first of these areas. It’s exceedingly complex, but we’ll know more about all of the sensory pathways in the brain with more research and experimenting.