Perception is the process by which we obtain and process information received through our senses 24 hours a day. From birth, infants are starting to develop perceptual abilities, and this development seems to reach a peak at 3 months. Vision is considered the most important of the five sensory modalities and a great deal of perceptual research focuses on it, just as this essay does. It is the purpose of this essay to show that infants demonstrate preferences in what they look at, seeming to prefer what is easily perceived or moderately different from what they normally 'expect'.

Detection in changes in brightness develops at a very early age, the pupils of newborns contracting in the presence of bright light and dilating in dim light (Pratt, 1954). And discrimination starts to occur as early as one week when babies choose to look more at lights of intermediate brightness than dim ones (Hershenson, 1964). We can expect, therefore, that a 3 month old child's sensitivity would be pronounced. For example, by only 2 months, infants can distinguish a white bar that only differs in luminance by 5% from a solid white background (Peeples & Teller, 1975).

Color sensitivity also develops rapidly. New born and two month old infants also have well developed color vision in general (Peeples & Teller, 1975; Schalker, 1975; Oster, 1975; Teller, Peeples and Sekel, 1978) but have trouble perceiving blue (review by Banks & Salapatek, 1983). Three month old infants have an adult level of color perception (Adams, 1987) and perhaps possess the physiological requirements for trichromatic vision, they even recognize variations in hue (Bornstein, Kessen and Weiskopf, 1976; Catherwood, Crassini and Freiberg, 1989). However, their preference is for colors of red and yellow as they are easier to perceive than an adults preference for blues and greens (Adams, 1987).

Visual acuity is the ability to perceive fine detail in the environment, and is often recalled in association with the Snellen eye chart, which provides a rating of acuity according to what the average person can see from a distance of 20 feet. That is, 20/20 vision would be considered normal, 40/20 exceptional and 20/60 poor. Infants cannot use eye charts and so are tested using increasingly fine striped patterns in the hope that a point will be reached at which acuity is lost. At three months visual acuity is estimated at 6/60 (Dobson and Teller, 1978).

Contrast sensitivity can be described as the smallest amount of contrast between image and background needed before a difference is detected. There is reason to believe that the development of both acuity and contrast sensitivity is related to the rapid development of the visual system, in particular the changes in the cells of the retina at 3 months and beyond (Banks & Bennett, 1988). Indeed, there is evidence that this development is related to physical maturation (Dobson et al., 1980; Miranda, 1970). Details still have to be large and clearly contrasted, although not to the degree of the neonate. Contrast sensitivity and visual acuity do not reach an adult level until approximately one year.

Research by Fantz (1961, 1963) using an apparatus called a looking chamber, refined the preference technique as we know it, giving remarkable insight into the preferences of infants when presented with two different visual stimuli and how they recognize patterns. He discovered that a face like pattern was preferred to any other rounded shape or pattern and further studies revealed that a schematically normal face was preferred over a scrambled one (Dannemiller & Stephens, 1988; Kagan, 1971). 3 month olds can also distinguish between a normal face and a face in which light and dark have been transferred, as in a photo negative (Dannemiller & Stephens, 1988). This is due to an increase in internal scanning at 3 months. Examples of infants preferring particular images are evident in the way a 3-month-old infant will recognize its mothers face and prefer it over others (Barrera & Maurer, 1981) or will look longer at faces that adults rate as attractive rather than unattractive faces (Langlois et al., 1987; Samuels & Ewy, 1985). An interesting factor is the development of a social responsiveness indicated by the infants preference for particular faces over others.

Scanning of internal features also aids in the infants perception of form and configuration at 3 months. Perception of form seems to indicate that the Gestalt principles for perception are innate (Aslin, 1987; Bornstein, Ferdinandsen & Gross, 1981; Van Giffen & Haith, 1984) and although some debate surrounds this theory I would tend to agree. A 3-month-old infant will focus on slight variations in form such as a missing portion of a circle (Van Giffen & Haith, 1984). Studies in which diamonds, squares and dots were arranged in different arrays (Vurpillot, Ruel and Castrec, 1977; Milewski, 1979) that resulted in the infant perceiving the overall form demonstrating similarity.

Perception of 3 dimensional form (depth and distance) is limited for the 3-month-old infant unless the object or form (moderately complex) is rotated on its axis or moving (Cook, Birch and Griffith, 1986; Kellman & Short, 1987; Owsley, 1983). Depth perception is often analysed using the "Visual Cliff" (Gibson & Walk, 1960) and the childs reaction at crawling age, and earlier by monitoring heart rate (Campos, Langer & Krowitz, 1970) when exposed to the 'deep' end under solid glass. Both exposures involve some movement. Overall, the infant has developed only kinetic depth cues rather than stationary ones.

It seems that the 3-month-old infant prefers bold and colorful patterns and objects of moderate complexity which are in motion. I have shown that preferences are guided by what the infant has the ability to see well.

References

Sigelman, C.K. & Shaffer, D.R. (1995). Lifespan human development (2nd ed.). Pacific Grove: Brooks/Cole. (Chapter 6).
Hayes, N. (1988). A first course in psychology (2nd ed.). Surrey: Thomas Nelson and Sons Ltd. (Chapter 12).
Ihsen, E. (1995). Study Guide: Human Development B. Chapter1: Perceptual development.
Myers, D.G. (1995). Psychology (4th ed.). New York: Worth Publishers. (Chapters 5 + 6)
Rosenblith, J.F. (1992). In the beginning. Development from conception to age two (2nd edn.). Newbury Park, CA: Sage.(pp. 251-293, 355-364).