Perceptual Development

According to our textbook, the study of perceptual development has been significant because it has been a key battleground in the dispute about nature versus nurture- though theorists who study perceptual development refer instead to the contrast between nativism and empiricism. Nativism is the view that most perceptual abilities are inborn. Empiricism argues that these skills are learned. This issue has been so central in studies of perception that researchers have focused almost all their attention on young infants; only by observing infants can they observe that organism when it is relatively uninfluenced by specific experience.

Sensory Skills
When the developmentalists study sensory skills, they are wanting to know what information the sensory organs receive. The common theme running through all of what we have read about sensory skills in chapter five is that newborns and young infants have far more sensory capacity than physicians or psychologists thought even as recently as a few decades ago. Perhaps because babies’ motor skills are so obviously poor, we assumed that their sensory skills were poor.

In a nutshell there are 5 main sensory skills: seeing, hearing, smelling, tasting, and touching. Several years ago, most medical textbooks stated that newborn infants were blind. Now we know that the newborn has poorer visual skills than older children but is definitely not blind. In adults, the usual standard for visual acuity is 20/20. At birth, an infant’s visual acuity is in the rain from 20/200 to 20/400, but it improves rapidly during the first year as a result of all the swift changes occurring in the brain described in a previous chapter, including myelination, dendritic development, and pruning. Most infants reach the level of 20/20 vision by about 6 months of age. As we learned in a previous chapter before, babies can hear long before they are born. However, like vision, hearing improves considerably in the early months of life. Although children’s hearing improves up to adolescence, newborns’ auditory acuity is actually better than their visual acuity.

Only with high-pitched sounds is their auditory acuity less than that of an adult. Babies’ senses of smell and taste have been studied much less than other senses. As in adults, the two senses are intricately related. Your taste sensitivity is also significantly reduced. Smell is registered in the mucous membrane of the nose. Taste is detected by the taste buds on the tongue, which register four basic tastes. They are sweet, sour, bitter, salty. Newborns appear to respond differentially to the four basic tastes. The infant’s senses of touch and motion might be the best developed of all senses. Motion perception is clearly presented even in the youngest infants, although a considerable degree of fine-tuning takes place over the first year of life.

Perceptual Skills
According to our textbook, in studies of perceptual skills, developmentalists are asking what the individual does with the sensory information. Researchers have found that very young infants are able to make remarkably fine discriminations among sounds, sights, and physical sensations, and they pay attention to and respond to patterns, not just to individual events. One important question to ask about visual perception is whether the infant perceives his environment in the same way as older children and adults. Developmentalists believe that infants’ patterns of looking at objects tell a great deal about what they are trying to gain from visual information.

According to our textbook, one of the perceptual skills that has been most studied in depth perception. You need this ability any time you reach for something or decide whether you have room to make a left turn before an oncoming car gets to you. An infant needs to be able to judge depth in order to perform all kinds of simple tasks. In the first 2 months, a baby’s visual attention is guided by a search for meaningful patterns. Babies scan the world around them. Early studies showed that babies as young as 1 month old can discriminated between speech sounds such as pa and ba. Studies have also shown that using conditioning head-turning responses by perhaps 6 months of age, babies can discriminate between two-syllable words.