Marshall, Peter J.2025-07-212025-07-212025-05https://scholarshare.temple.edu/handle/20.500.12613/11152The emergence of prehension, the ability to reach out and grasp an object, marks the start of a shift in infant development by allowing the refined exploration of objects by hand. The onset of purposeful reaching in infancy begins a developmental cascade involving cognitive, motoric, social-emotional, and communicative abilities. Currently, there is a gap in the literature surrounding the development of preshaping, which is the skill of adapting the fingers during approach to grasp an object in a fluid motion. Preshaping can be studied by examining the emergence of the pincer grasp, where only the thumb and index finger are used and these digits are oriented to the object during the reach. We combine novel methodology in video data collection, kinematic analysis, and an electroencephalography (EEG) paradigm to map the development of preshaping from 6 to 14 months of age. Video data were collected biweekly at home by caregivers via a cell phone app. These data underwent kinematic analysis through a machine learning algorithm (HaMeR) to quantify finger movements. EEG data was collected at 14 months old from a tactile oddball paradigm. We found that infants are beginning to preshape their hand gradually from six months old, likely reflecting the integration of vision and touch. The EEG data suggested that by 14 months old, infants show functional groupings of fingers that are similar to that of an adult. Behaviorally coded grasping strategies, but not the change in the degree of preshaping as derived from kinematic data, predicted whether infants display two neural categories of their hand. These subtleties of the interplay between behavioral and neural development can inform our understanding of the relations between the body and brain and can potentially inform identification of motor differences and delays in childhood.95 pagesengIN COPYRIGHT- This Rights Statement can be used for an Item that is in copyright. Using this statement implies that the organization making this Item available has determined that the Item is in copyright and either is the rights-holder, has obtained permission from the rights-holder(s) to make their Work(s) available, or makes the Item available under an exception or limitation to copyright (including Fair Use) that entitles it to make the Item available.http://rightsstatements.org/vocab/InC/1.0/Developmental psychologyNeurosciencesBrain-bodyGraspingInfancyKinematicsPrehensionsMMNPsychologyText2025-06-16Campbell_temple_0225E_16045.pdf