Part of getting onto a good masters or Ph.D programme means having real-life experience. As only a second year undergraduate that can sometimes seem like an age away, but time really does fly by. In order to get some experience in research I transcribed videos for a developmental researcher at my department. Even though my job was pretty menial in the whole scale of things, writing down all the speech and movements of infants really made me appreciate something substantial; infants are very hard to understand and observe. Their intentions, their desires and even just their knowledge can be difficult to interpret. As such, psychologists use a set of methods to study infant perception, intentions, desires and capabilities.
This post will deal with studying infant perception.
1. A researcher presents two stimuli to an infant simultaneously
2. The researcher monitors the infant’s eye movement. Researchers use various techniques for this, one being the ASL Model 504.
3. If the infant looks more at one stimulus than the other, it is inferred that the infant prefers that stimulus over the other.
If accurate, measures of the eye movements can be made, this technique is quite simple and effective. The infants preference can be inferred because of habituation, a fancy word for boredom.
Habituation and dishabituation are another method used to study infant perception and preference. After looking at a stimulus for a certain amount of time, we become bored of it. Just like after awhile we stop feeling the clothes on our body. Our brain gets bored with the touch sensation, and so eventually it stops informing us of it. On this basis, psychologists infer that babies will stop looking at a stimulus if they gets bored of it. If a stimulus is then presented with a new stimulus, it is likely he or she will prefer looking at the new stimulus that the infant has not seen before. If the infant does prefer the new stimulus, we can infer that the infant is capable of discriminating between the two stimuli. Discrimination between two stimuli allows researchers to detect the stage of perceptual development of infant has reached.
Classical and operational conditioning are terms you should be familiar with have you ever taken an introductory psychology course. Conditioning with infants consists of the same learning system. Fortunately, infant studies usually just involve rewarding the infant with pleasant sounds or images, usually of or from their mother.
1. Infant is given a dummy or pacifier
2. Researcher waits for the infant to begin sucking on it at their usual rate
3. If the infant begins sucking at a faster rate than usual they are rewarded with the sound of their mothers voice
4. The infant will soon learn that as long as her or she continues sucking at the increased rate, they will hear their mother’s voice
5. After awhile, habituation sets in as the baby loses interest in the sound and their sucking rate decreases
6. The researcher then proceeds to introduce a new sound
7. If the infant is capable of discriminating the new sounds, they will begin to suck more again to her this new sound
All of these various tests of perception, as mentioned above are used to measure the development of infants.