The tool effect is lower in older adults with or without cognitive impairments than in young adults.

Grabbing a phone from a table or stepping over an obstacle on the ground are daily activities that require the brain to take account of both object and the body's parameters. Research has shown that a person's estimated maximum reach is temporarily overestimated after using a tool, even when the tool is no longer in hand. This tool effect reflects the high plasticity of the perceptual-motor system (e.g., body schema updating)-at least in young individuals. The objective of the present study was to determine whether the tool effect is smaller in older adults. Forty-four young adults, 37 older adults without cognitive impairment and 30 older adults with cognitive impairment took part in the experiment. The task consisted in visually estimating the ability to reach (using the index finger) a target positioned at different locations on a table, both before and after using a rake. We observed a strong after-effect of tool use in the young adults only. Conversely, a tool effect was similarly absent in the older adults without and with cognitive impairment. Moreover, even before the tool was used, the maximum reach was overestimated in each of the three groups, although the overestimation was greatest in the two groups of older adults. In summary, we showed that the tool effect, observed in young adults, was absent in older adults; this finding suggests that with advancing age, the perceptual-motor system is less able to adapt to novel sensorimotor contexts. This lack of adaptation might explain (at least in part) the overestimation of motor skills often reported in the elderly.

[Assessment of verbal episodic memory by a new memory test with self-initiated items (MAI test)]. / Évaluation de la mémoire épisodique des personnes âgées : normalisation d'une nouvelle épreuve de mémoire avec items auto-initiés (MAI).

The assessment of episodic memory is a critical aspect of psychometric assessment in elderly people, particularly for the diagnosis of dementia. However, evaluation of episodic memory in these subjects is not easy in subjects with non-native language, different culture, visual impairment or fatigability. To overcome these difficulties, a rapid assessment of episodic memory, the Auto-initiated memory test (MAI test) has been developed. The goal of our research is to validate and standardize this test. To achieve the standards, we included 84 non-demented older participants (74.24±6.9 years). Moreover, we included 171 older participants with cognitive impairment and 33 older participants with Mild cognitive impairment. The results showed that the MAI test (phase 2 of the test) has good psychometric properties in MCI patients (sensitivity=76%, specificity=100%). Thus it appears to be an useful screening tool for detection of pre-dementia in subjects who are not able to pass usual standard tests of episodic memory.

[Force platforms, a technological innovation]. / Les plates-formes de force, une innovation technologique.

Falls in the elderly constitute a public health issue due to the seriousness of the physical and psychological consequences as well as the resulting financial cost. Static posturography with the help of a force platform helps to guide therapeutic decisions and to rehabilitate patients who have fallen.