Event Related Potentials in Infants and Adults

The major objective of this research is to better understand the response of the brain to
significant stimulation in early and later development. The proposed work is designed to
examine infants', children's, and adults' (especially mothers') responses to salient features
of the external environment. To do so, the present research studies the biological bases and
behavioral significance of natural preferences and information processing. The primary
research strategy to be used consists of analyzing behavioral and brain responses to visual
patterns. In a laboratory procedure, subjects will explore patterns and their brain
electrical activity will be measured simultaneously with an electronic analysis system. In
specific, five experiments of visual attention in human infants, and 1 experiment in adults
are proposed. In the first experiment with infants, babies are hypothesized to look longer at
more saturated colors; in a second experiment, babies are hypothesized to look longer at
gratings aligned along the vertical and horizontal orthogonals than along the obliques.
Because saturated colors and orthogonal stimulation elicit greater activity in visual system
neurons and greater amplitude evoked potentials than desaturated colors or oblique
stimulation, respectively, these two experiments explore the hypothesis that the simple
visual stimuli to which infants preferably attend are those that are particularly appropriate
in stimulating the geniculostriate or primary visual system. In the third experiment, we plan
to trace the ontogeny of the mature brain response to whole patterns as opposed to parts of
patterns. In a fourth experiment, we intend to compare region-specific activity when the
surface features of a familiarized visual target change to that when its location changes. In
the fifth experiment, we examine individual differences in the power metrics associated with
attention to visual stimuli in relation to individual differences in their corresponding
behavior coded by observers. In an experiment with children and adults we will explore brain
responses and their localization in to pictures of familiar and unfamiliar faces.

- INCLUSION CRITERIA:

Participants will be selected for inclusion in this study and each to follow on the basis
of age, gestational status (i.e., full-term vs. pre-term birth), visual normality, and
general health status. Once the recruitment letters have been mailed, a brief screening
interview will be conducted with all parents who call to express an interest in
participating. These parents will be asked about their infants birth date, expected due
date, and any diagnoses of severe perinatal complications, visual abnormalities, and
congenital developmental disorders. Infants with a gestational age of less than 36 weeks,
and/or those with histories of severe perinatal complications, visual abnormalities, or a
family history of color-vision deficiency will not be recruited for participation. Equal
numbers of males and females will be recruited to participate.