Kelly A. Snyder
Assistant Professor, Developmental and DCN

My research examines the functional neurobiology and development of learning and memory in infants and young children. We are particularly interested in the functional development of the hippocampal memory system supporting declarative (explicit) memory, and the roles that attention, motivation, and emotion play in early learning. In my laboratory, we combine behavioral methods (e.g., eye tracking, preferential-looking methods) and high-density event-related potentials (ERPs) to study early learning and memory. The long-term goal of this work is to understand how the brain systems involved in learning (e.g., attention, motivation, memory) become organized during development, the role that experience may play in shaping these systems, and how the development of functional interactions between different neural subsystems affects cognitive development.

One program of research investigates the functional neurobiology underlying visual preferences for novelty. Novelty preferences (longer fixations on new stimuli than on previously presented stimuli) are widely used to assess memory in non-verbal populations like human infants and experimental animals, yet important questions remain about the nature of the processes that underlie them. My research in this area examines whether novelty preferences reflect a form of declarative memory mediated by the hippocampal memory system, or a form of biased competition in visual selective attention mediated by repetition suppression in visual perceptual areas. Drawing from animal models and adult neuroimaging work, we are using high-density ERPs and EEG (e.g., gamma oscillations) to investigate the neural mechanisms underlying infant memory in habituation and novelty detection paradigms.

Dual-process theories of recognition memory hold that the recognition of previously encountered items can be based on conscious recollection of past events and/or assessments of familiarity. Familiarity is conceived as a fast, relatively automatic process that relates to the experience of having previously encountered someone or something in the absence of memory for the specific context (e.g., where, when) in which the previous encounter occurred. Recollection, on the other hand, is thought to be a slower, more effortful process that involves conscious access to contextual information about a previous encounter. In addition to these functional distinctions, recollection and familiarity are also thought to be dissociable at the neural level, with recollection depending primarily on the hippocampus and familiarity depending more on parahippocampal structures and cortical processing mechanisms. We are investigating the development of recollection and familiarity using ERPs and non-verbal behavioral tasks known to dissociate these processes in adults and experimental animals.

Relational memory refers to memory for the relations (or arbitrary associations) among individual items, such as the spatial relationships among objects in a scene or the arbitrary associations between a name and a face, and is thought to depend critically on the hippocampus. We are investigating the development of relational memory in infants using ERPs and assessments of eye movements that infants naturally make while passively viewing scenes.

A final program of research investigates the interaction between affective and cognitive processes during development. Specifically, we are interested in whether objects in the environment to which an infant attaches emotional significance may be attended to and processed differently than objects that hold no particular significance. We are using high-density ERPs to investigate affective modulation of visual processing and its subsequent influence on visual attention and memory.

Recent, Representative Publications

Snyder, K.A., Blank, M.P., & Marsolek, C.J. (in press). What form of memory underlies novelty preferences? Psychonomic Bulletin & Review.

Snyder, K.A., & Torrence, C.M. (in press). Habituation and Novelty. In M.M. Haith & J.B. Benson (Eds.), Encyclopedia of Infant and Early Childhood Development. Elsevier: Oxford.

Pennington, B.F., Snyder, K.A., & Roberts, R.J. (in press). Developmental Cognitive Neuroscience: Origins, Issues, and Prospects. Developmental Review.

Snyder, K.A. (2007). Neural mechanisms underlying memory and attention in preferential-looking tasks. In L.M. Oakes & P.J. Bauer (Eds.), Short- and long-term memory in infancy and early childhood: Taking the first steps toward remembering. Oxford Press.

Davis, E.P., Bruce, J., Snyder, K.A., & Nelson, C.A. (2003). The X-trials: Neural correlates of an inhibitory control task in children and adults. Journal of Cognitive Neuroscience, 15(3), 432-443.

Snyder, K.A., Webb, S.J., & Nelson, C.A. (2002). Theoretical and methodological implications of variability in infant brain response during a recognition memory paradigm. Infant behavior & development, 25, 466-494.

Director
Developmental Cognitive Neuroscience Lab