MENTAL ROTATION IN HUMAN INFANTS
Mental rotation is the process by which people imagine how an object would look after it has been rotated into a different orientation in space; taking other people’s perspectives and learning to find one’s way around a new environment are skills that likely depend on this ability. My current research on the development of mental rotation in infancy is seeking to reveal if the sex differences in this ability that are found in adulthood also exist in infancy, before extensive social experiences have contributed differentially to the ways in which boys and girls think. This work will shed light on the development of this vital skill, and could ultimately facilitate formulation of diagnostics and treatments for developmental disorders like dyslexia (characterized by perceptual deficits that lead to errors involving reversals of symmetrical letters like “b” and “d”), and other conditions associated with abnormal spatial cognition.
EVALUATION OF INFANT ATTENTION USING EEG
My research on infant attention uses an EEG (electroencephalogram) system to study the development of attention in infancy; the goal is to determine if electrical activity in infants’ brains can be used to reveal if they are paying attention to a visual display. These studies explore the relationship between the amplitude of the so-called “steady state visual evoked potential” (also known as SSVEP) and the frequency at which a checkerboard stimulus is seen flickering. Among the goals of this work is to explore if SSVEPs are subject to habituation (i.e., the process that occurs when an infant gets bored of looking at a familiar stimulus) and to examine the possibility that SSVEPs can reveal so-called “covert” attention, in which infants are actually attending to a stimulus that they are not looking at. We also hope to gather data that will allow evaluation of my hypothesis that infants can mentally rotate 2-dimensional representations of 3-dimensional objects; this study would investigate if male and female infants differ in their SSVEP-revealed mental rotation abilities, as they do in their behaviorally-revealed mental rotation abilities.
CATEGORIZATION OF INFANT-DIRECTED SPEECH
In almost all of the world’s cultures, adults speak to infants in a distinctive tone of voice, and infants are known to prefer such infant-directed (ID) speech to normal adult-directed speech. My research on ID speech is designed to explore how pre-verbal infants categorize ID utterances, and to ascertain how infants’ categories of ID speech change with development. These data are important because they address the possibility that ID utterances give infants access to information about a speaker’s affect and intentions; evidence about when infants first categorize ID speech in adult-like ways will indicate when they finally possess perceptual processing skills required to understand ID speech. Such data should elucidate the timing and nature of the developmental events that lie on the pathway normal infants follow to genuine communicative competence. These data will also help to portray the normative development of ID speech categorization, and so will be useful in identifying infants at risk for later development of communicative dysfunction.