[Effect of aging on real route memorization: the role of working memory and episodic memory]. / Effet du vieillissement sur la mémorisation d'itinéraires réels : l'importance de la mémoire de travail et de la mémoire épisodique.

This research investigates the role of different memory components in the age-related decline of new route learning. Few studies have considered real route learning, for which the situation can be more complex, and the richness greater than with simple mazes. In this experiment, the memory of a route in a real city has been assessed considering visual scene recognition, directions recognition, and temporal order memorization. Thirty young adults (m=25 years old) and 30 older adults (m=70 years old) have watched the video of the route twice before performing the three recognition tasks. Various cognitive abilities (episodic memory, verbal and visuo-spatial working memory, short-term binding, inhibition, flexibility, and mental rotation ability) have then been assessed through different neuropsychological tests. The results demonstrate that older adults have poorer performance than younger in the three route learning tasks: visual scene recognition task, direction recognition task, and temporal order recognition task. Moreover, mediation analyses indicate that episodic memory performance partly explains the effect of aging on visual scene recognition, while working memory capacity performance (measured with Corsi's block test, digit span test, and multimodal span test) partly explains the effect of aging on direction recognition. Spatial memory involved in real navigation and route learning is thus impaired in normal aging, which is partly due to the decline of episodic and working memory components.

Ocular pursuit and visual memory of moving shapes.

This paper deals with visual memory of moving shapes. During a visual recognition task, shapes moved on a computer screen, at a constant speed, and in a direction that was either similar, orthogonal or opposite to the direction of motion during learning. Results showed that correct response rate varies according to oculomotor factors: (1) the motor skill of ocular pursuit during learning and (2) the compatibility between motor control of ocular pursuits during learning and recognition. These data suggest that recognition of a moving shape is linked to recognition of ocular pursuits that subjects had previously repeated during shape learning. Possible neural substrates underlying this sensorimotor integration are discussed. More generally, these data shed light on the role of eye movements in visual memory organization.

Mental rotation and simulation of a reaching and grasping manual movement.

This paper deals with the kind of manual movement subjects mentally simulate when solving a left-right judgment task that requires rotating images of hands. 50 female students were asked to judge the laterality of drawings of rotated hands presented successively to the right and left visual hemifields by clicking on a mouse using either the right or left hand. Reaction times and accuracy of judgment were recorded. Analysis showed performances varied with the rotation angle at which the stimulus was presented, indicating that the subjects mentally simulated a rotation process. An interaction occurred between the visually presented hand and the responding hand, which suggests that the mental rotation process involved the simulation of a hand movement. Performance improved when the drawing of a hand was presented in the 'palm-up' position, and to the visual hemifield opposite with respect to the hand the subject moved mentally. The latter two findings suggest that the subjects performed a simulated reaching and grasping movement rather than a simulated positioning movement.