Shape seems to be the most important factor in babies' deciphering of the boundaries between two objects, according to a study by Amy Needham, assistant professor of psychology, Duke University, Durham, N.C. She discovered that four-month-olds rely more on shape than color or pattern to figure out that objects placed side by side were separate, rather than a single unit. This suggests a continuity in the way infants and adults analyze objects they see, since shape is a critical element of adults' perception of the distinction between objects.
Because infants begin their learning process long before they are able to indicate their curiosity about their surroundings verbally or even by reaching for something, researchers use "looking time" as a measure of interest or analysis. "The kind [of measure] we use is based on the assumption that babies look at things longer if they're puzzled by what,they see or if it violates some kind of expectation that they have about the world than if what they see is pretty much in line with what they expect," Needham explains.
In the study, researchers tracked the looking time of 48 babies as they were shown one of three different displays, each consisting of two objects placed against each other. In the first, the objects were similar in shape (rectangular on the bottom and rounded on the top, or roughly loaf shaped), color, and pattern. In the second, they were the same color and pattern, but different shapes--one loaf and one rectangle. Objects in the third display were the same shape, but different colors and patterns. …