Exploring the bases of hippocampal- and prefrontal-based memory : the effect of age and disease

Abstract

Memory formation largely depends on normal function of the temporal lobes (particularly the hippocampal complex) and the prefrontal cortex. The relationship between these two regions and the degree to which each region is engaged during different memory tasks is still unclear. Evidence from animal studies suggests abnormal hippocampal functioning in hypothyroidism (Alzoubi, Gerges, & Alkadhi, 2005), and abnormal prefrontal functioning in aging (Allain et al., 2005). This study investigates the nature of the relationship between memory tasks that have been associated with hippocampal and prefrontal cortex (PFC) regions, and examines how this relationship changes when either region is damaged; the hippocampus as a result of hypothyroidism, and the prefrontal cortex as a result of aging. It is hypothesised that specific defects in memory tasks associated with the hippocampus will be observed in hypothyroid patients, while specific deficits in memory tasks associated with both prefrontal- and hippocampal regions will be observed in healthy older adults.