The purpose of the study to is to examine whether in utero exposure to cocaine compromises cognitive and motivational processes underlying infants' reaching behavior. Data have already been collected on 99 infants using a paradigm developed by the PI to encourage infants' manipulation of seen or remembered objects. This is an ancillary study to the longitudinal, multi-center Maternal Lifestyles Study (MLS). Based on maternal history and meconium assay, 40 infants were identified as exposed in utero and 59 were nonexposed; 39% were preterm. During the procedure, sixteen trials were presented to the infant in which 4 objects emitting sounds moved clockwise into the infant's reaching space in the light and dark. Sessions were videotaped for later coding of reaching, attention, affect, motivation, localization, and recognition. The proposal requests resources to complete the behavioral coding as well as conduct kinematic analysis of infants' reaches. Kinematic measures describe the quality of the reaching process and are likely to reflect neuromotor deficits as well as cognitive and affective components of motor planning. This project has 6 specific aims that examine:
(Aim 1) the effects of cocaine exposure on the components of infants' reaching activity including attention/motivation, efficiency of the reaching outcome, auditory localization and object recognition;
(Aim 2) whether cocaine exposure affects infants' modulation of attention, affect or action during exploration of the environment;
(Aim 3) whether cocaine exposure affects the quality or efficiency of the reaching process as shown by kinematic parameters, e.g., smoothness, straightness, velocity, (Aim 4) if the effects of cocaine exposure persist when medical or lifestyle factors that co-occur with cocaine exposure including low birthweight, marijuana use, alcohol use, and low socioeconomic status are covaried;
(Aim 5) the construct and predictive validity of reaching measures using comparable variables from the MLS protocol including measures of motivation, attention, and action at 8 and 12 months;
(Aim 6) the interrelations of cocaine exposure, cognitive, and motor behavior in order to determine if reaching is mediated by infants' modulation of cognitive and affective processes and cocaine exposure. The unique paradigm used in this study allows fine grain analysis of the motor act within the larger context of attentional and motivational processes when the task is easy (in the light) and more difficult (in the dark). Positive results not only describe infants' exploratory behavior but also identify possible mediators and moderators for the effects of cocaine exposure. Results of this study increase the knowledge base of the effects of cocaine exposure on developmental processes and outcomes essential to cognitive development.
