Egocentric and allocentric spatial memory in healthy aging: performance on real-world tasks

Although normal aging has been related to several cognitive difficulties, other processes have been studied less, such as spatial memory. Our aim was to compare egocentric and allocentric memory in an elderly population using ecological tasks. Twenty-eight cognitively unimpaired participants performed Egocentric and Allocentric Spatial Memory Tasks, as well as Spatial Span from CANTAB, Benton's Judge of Line Orientation test (JoLO), and Montreal Cognitive Assessment test (MoCA). The results revealed that younger participants showed better performance than older participants on both the Egocentric and Allocentric Spatial Memory Tasks, although only the Egocentric test was able to discriminate between younger, middle, and older elderly participants. Learning effect was found in Allocentric Spatial Memory Task in younger and older groups, but not in the middle group. Allocentric and egocentric performance was not related to other visuospatial neuropsychological scores and gender did not influence performance in any task. Egocentric and Allocentric Spatial Memory Tasks may be useful tools in early screening for cognitive decline, as they are able to detect age differences in the cognitive unimpaired elderly population.

Small-scale environmental enrichment and exercise enhance learning and spatial memory of Carassius auratus, and increase cell proliferation in the telencephalon: an exploratory study

Carassius auratus is a teleost fish that has been largely used in behavioral studies. However, little is known about potential environmental influences on its performance of learning and memory tasks. Here, we investigated this question in C. auratus, and searched for potential correlation between exercise and visuospatial enrichment with the total number of telencephalic glia and neurons. To that end, males and females were housed for 183 days in either an enriched (EE) or impoverished environment (IE) aquarium. EE contained toys, natural plants, and a 12-hour/day water stream for voluntary exercise, whereas the IE had none of the above. A third plus-maze aquarium was used for spatial and object recognition tests. Different visual clues in 2 of its 4 arms were used to guide fish to reach the criteria to complete the task. The test consisted of 30 sessions and was concluded when each animal performed three consecutive correct choices or seven alternated, each ten trials. Learning rates revealed significant differences between EE and IE fish. The optical fractionator was used to estimate the total number of telencephalic cells that were stained with cresyl violet. On average, the total number of cells in the subjects from EE was higher than those from subjects maintained in IE (P=0.0202). We suggest that environmental enrichment significantly influenced goldfish spatial learning and memory abilities, and this may be associated with an increase in the total number of telencephalic cells.

Relationship between visuospatial episodic memory, processing speed and executive function: are they stable over a lifespan? / As relações entre memória episódica visual-espacial, velocidade de processamento e funções executivas são estáveis ao longo do ciclo vital?

ABSTRACT The present study evaluated the association between episodic memory, executive function and processing speed in a sample with different age ranges. We tested the hypothesis that processing speed, executive function and memory are more strongly associated during childhood and old age. We evaluated 571 participants, aged six to 92 years, divided into four age groups: children/adolescents, young adults, middle-aged adults and older adults. Correlation analyses suggested that the shared variance between the processing speed and memory is strong in childhood but weak across other age ranges. Executive function, however, had a stronger association both in childhood and in old age, when compared with the intermediate stages. We conclude that the effects of processing speed and executive function on memory are not stable across human development. These functions may be compensatory mechanisms for memory functioning in childhood and old age.

RESUMO O presente estudo avalia a associação entre velocidade de processamento, funções executivas e memória em uma amostra de diferentes faixas etárias. O estudo testa a hipótese de que a velocidade de processamento, as funções executivas e a memória apresentam associação mais forte na infância e na velhice. Avaliamos 571 participantes, com idade entre seis e 92 anos, divididos em quatro grupos etários: crianças/adolescentes, adultos jovens, adultos de meia-idade e idosos. Análises de correlação sugerem que a variância compartilhada entre velocidade de processamento e memória é forte na infância e fraca nas demais idades. Já as funções executivas apresentaram associação forte com a memória tanto na infância quanto na velhice, quando comparadas aos estágios intermediários. Concluímos que os efeitos da atenção sobre a memória variam em função da idade do participante. Essas funções podem ser mecanismos compensatórios para a memória ao longo do desenvolvimento.

The influence of enriched environment on spatial memory in Swiss mice of different ages / A influência do ambiente enriquecido na memória espacial de camundongos Swiss em diferentes faixas etárias

The objective of this study was to evaluate the influence of enriched environment on spatial memory acquisition in mice of three different age groups. Weanling, young, and young adult female Swiss mice were housed in a standard control or enriched environment for 50 days, and their spatial memory was tested with the Morris Water Maze. We did not observe an experimental effect for spatial memory acquisition, and there was neither an effect of time of analysis nor an interaction between experimental group and time of analysis. Regarding effects of experimental group and training day in relation to latency in finding the hidden platform, we did find an effect in the experimental young adult mice group (p = 0.027), but there was no interaction between these factors in all three groups. Based on these findings environmental enrichment did not enhance spatial memory acquisition in female Swiss mice in the tested age groups.

O objetivo deste estudo foi avaliar a influência do ambiente enriquecido na aquisição da memória espacial de camundongos em três diferentes faixas etárias. Camundongos fêmeas Swiss recém-desmamados, jovens e adultos jovens foram alojados em ambiente controle ou em ambiente enriquecido durante 50 dias, e sua memória espacial foi testada por meio do Labirinto Aquático de Morris. Não houve efeito do grupo experimental na aquisição de memória espacial, do momento de análise, tampouco da interação entre o grupo experimental e o momento de análise. Quanto aos efeitos do grupo experimental e do dia de treino em relação à latência para encontrar a plataforma escondida, houve efeito do grupo experimental apenas para o grupo experimental adulto jovem (p = 0,027), com menor latência do grupo controle, porém sem interação entre esses fatores para todos os grupos. O enriquecimento ambiental não interferiu na aquisição de memória espacial de camundongos fêmeas Swiss nas faixas etárias analisadas.