The organization of memory for familiar songs

Investigated the organizing principles in memory for familiar songs in 2 experiments. It was hypothesized that individuals do not store and remember each song in isolation. Rather, there exists a rich system of relationships among tunes that can be revealed through similarity rating studies and memory tasks. One initial assumption was the division of relations among tunes into musical (e.g., tempo, rhythm) and nonmusical similarity. In Exp I, 20 undergraduates were asked to sort 60 familiar tunes into groups according to both musical and nonmusical criteria. Clustering analyses showed clear patterns of nonmusical similarity but few instances of musical similarity. Exp II, with 16 Ss, explored the psychological validity of the nonmusical relationships revealed in Exp I. A speeded verification task showed that songs similar to each other are confused more often than are distantly related songs. A free-recall task showed greater clustering for closely related songs than for distantly related ones. The relationship between these studies and studies of semantic memory is discussed. Also, the contribution of musical training and individual knowledge to the organization of the memory system is considered. (19 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)

Maternal and Postweaning High-Fat Diets Disturb Hippocampal Gene Expression, Learning, and Memory Function

We tested the hypothesis that excess saturated fat consumption during pregnancy, lactation, and/or postweaning alters the expression of genes mediating hippocampal synaptic efficacy and impairs spatial learning and memory in adulthood. Dams were fed control chow or a diet high in saturated fat before mating, during pregnancy, and into lactation. Offspring were weaned to either standard chow or a diet high in saturated fat. The Morris Water Maze was used to evaluate spatial learning and memory. Open field testing was used to evaluate motor activity. Hippocampal gene expression in adult males was measured using RT-PCR and ELISA. Offspring from high fat-fed dams took longer, swam farther, and faster to try and find the hidden platform during the 5-day learning period. Control offspring consuming standard chow spent the most time in memory quadrant during the probe test. Offspring from high fat-fed dams consuming excess saturated fat spent the least. The levels of mRNA and protein for brain-derived neurotrophic factor and activity-regulated cytoskeletal-associated protein were significantly decreased by maternal diet effects. Nerve growth factor mRNA and protein levels were significantly reduced in response to both maternal and postweaning high-fat diets. Expression levels for the N-methyl-D-aspartate receptor (NMDA) receptor subunit NR2B as well as synaptophysin were significantly decreased in response to both maternal and postweaning diets. Synaptotagmin was significantly increased in offspring from high fat-fed dams. These data support the hypothesis that exposure to excess saturated fat during hippocampal development is associated with complex patterns of gene expression and deficits in learning and memory.