Switching from reaching to navigation: differential cognitive strategies for spatial memory in children and adults

Abstract

Navigational and reaching spaces are known to involve different cognitive strategies and brain networks, whose development in humans is still debated. In fact, high-level spatial processing, including allocentric location encoding, is already available to very young children, but navigational strategies are not mature until late childhood. The Magic Carpet (MC) is a new electronic device translating the traditional Corsi Block-tapping Test (CBT) to navigational space. In this study, the MC and the CBT were used to assess spatial memory for navigation and for reaching, respectively. Our hypothesis was that school-age children would not treat MC stimuli as navigational paths, assimilating them to reaching sequences. Ninety-one healthy children aged 6 to 11 years and 18 adults were enrolled. Overall short-term memory performance (span) on both tests, effects of sequence geometry, and error patterns according to a new classification were studied. Span increased with age on both tests, but relatively more in navigational than in reaching space, particularly in males. Sequence geometry specifically influenced navigation, not reaching. The number of body rotations along the path affected MC performance in children more than in adults, and in women more than in men. Error patterns indicated that navigational sequences were increasingly retained as global paths across development, in contrast to separately stored reaching locations. A sequence of spatial locations can be coded as a navigational path only if a cognitive switch from a reaching mode to a navigation mode occurs. This implies the integration of egocentric and allocentric reference frames, of visual and idiothetic cues, and access to long-term memory. This switch is not yet fulfilled at school age due to immature executive functions.

Cognitive strategies for locomotor navigation in normal development and cerebral palsy

“…In fact, several strategies and brain networks can be used to solve a task like the Magic Carpet. As previously shown, the Magic Carpet fosters a switch from ego‐ to allocentric spatial encoding, but it can also be solved, although less efficiently, by egocentric updating. These strategies rely on different brain networks, the former centred on hippocampal and prefrontal areas, the latter on posterior parietal and premotor cortices .…”

“…Control data were obtained from a sample of 91 typically developing children aged 5 to 12 years, as described elsewhere . From that sample, a subset was extracted by age‐ and sex‐matching them with children with CP, then randomly selecting one matched child per patient.…”

“…Thus, a larger non‐matched comparison group consisting of all 91 typically developing children and a smaller group of 17 age‐ and sex‐matched children were obtained. The larger non‐matched comparison group was retained to provide a double statistical check, because a major part of the variability found in typical development is known to be due to neither age nor sex …”

“…CBT performance is linearly related to age in typical development and is impaired in CP . Recently, a computerized navigational version of the CBT, the Magic Carpet test, has been developed from the manual Walking Corsi test, and used to study navigation development . The present study aims to extend the investigation to children with CP.…”

Anticipatory control and spatial cognition in locomotion and navigation through typical development and in cerebral palsy

“…An increasing ability to switch from ego-to allocentric encoding is postulated as the reason for these developmental changes, since it would allow to retrieve the global path rather than single locations. 27 The table Corsi and Magic Carpet tasks have been proposed to children with CP. The effects of congenital brain lesions were studied in a sample of 22 children with unilateral and bilateral spastic CP aged 5 to 14 years.…”