Manipulating spatial frequency to understand global and local information processing in 7-month-old infants
It has been shown that infants build representations of their visual world by forming relations among its parts. However little is known about how they select the parts to relate. One possibility is that while constructing their visual world part by part they are also decomposing it, using finer and finer parts. One way to test this theory is to simply control the parts infants see. This easiest way to do this is to filter real life objects of their high and low spatial frequencies. High spatial frequencies provide information about the smaller parts where as low spatial frequencies provide information about the larger ones. By removing high or low spatial frequency we can control the coarseness of their representation and ultimately determine the level at which they function best. The present study examined infants’ ability to use high and low spatial frequencies to discriminate between objects. Infants were habituated and tested using a combination of high and low spatial frequency images. Only infants experiencing a consistent spatial frequency across habituation and test were able to discriminate between objects. Infants were also better at discriminating between objects containing high spatial frequencies. In a second study designed to be more true to life, infants were habituated to broadband images and tested using high or low spatial frequencies. This time infants did not discriminate between objects but they did look longer at low spatial frequency information than at the high. From these findings we can conclude that infants use both high and low spatial frequency information when discriminating objects, and that in certain cases one frequency may become more important than the other. The spatial frequency they use may be dependent on the context of the task. Numerous studies have shown that adults prioritize high and low spatial frequency information depending on how fast they want to process the object, the amount of detail they require, and whether they used high or low spatial frequency information during previous experiences. Infants may be similar. At times they may emphasize low spatial frequency information and the big picture. At other times they may emphasize high spatial frequency information and the detail. More studies examining how infants select information for processing are necessary and spatial frequency will likely to be an important tool in the investigation.