Rethinking Memory in Typical and Atypical Development: New Perspectives from Cognitive Neuroscience

Abstract

Recent research provides evidence for new conceptualizations of memory, including the brain's drive to predict and anticipate future events based on past experiences, a narrowing gap between perceptual and mnemonic functions, and the importance of sleep-dependent memory consolidation. These new perspectives, which highlight the interactive nature of the brain bases of memory, are rarely applied to the study of memory in neurodevelopmental disorders. In the present work, I adopted some of these theoretical perspectives to rethink the study of memory in typical development and in neurodevelopmental disorders such as Down syndrome (Trisomy 21). Given that several studies have reported atypical patterns of brain connectivity in individuals with Down syndrome, this dissertation aims to assess the integrity of memory processing in this population by examining different levels of cross-regional communication measured at the neuropsychological level. I first provide evidence of impaired rapid interactions between the brain areas that mediate high-level influences on figure-ground perception and relatively unimpaired integration of neural inputs across local areas of visual cortex (Spanò, Peterson, Nadel, Rhoads, & Edgin, 2015; see Appendix A). In the second study, I demonstrate spared use of anticipatory scene representation, thought to rely on top-down information from the hippocampus and likely to support our understanding of the properties of the visual world (Spanò, Intraub, & Edgin, submitted; see Appendix B). Finally, the third study reveals impaired sleep-dependent memory consolidation of arbitrary object-label associations, symptomatic of a weak dialogue between prefrontal cortex and hippocampus (Spanò, Gómez, Demara, Alt, Cowen, & Edgin, in preparation; see Appendix C). Based on these findings, treatments for Down syndrome, and other developmental disorders affecting functional connectivity, should be aimed at establishing balanced neural communication and cross-regional connectivity early on in development.