Even chicks may count from left to right: For the most part, humans represent numbers across a mental number line, with smaller numbers on the left and larger numbers on the right. Some have argued that this is due to culture rather than being innate. Rugani et al. , however, show that 3-day-old chicks share this representation of numbers, consistently seeking lower numbers to the left of a target and larger numbers to the right (see the Perspective by Brugger). These results suggest that there may be an innate spatial representation of numerical values that we share with other animals. Science , this issue p. 534 ; see also p. 477

Background. Memory decline is a prevalent aspect of aging but may also be the first sign of cognitive pathology. Virtual reality (VR) using immersion and interaction may provide new approaches to the treatment of memory deficits in elderly individuals. Objective. The authors implemented a VR training intervention to try to lessen cognitive decline and improve memory functions. Methods. The authors randomly assigned 36 elderly residents of a rest care facility (median age 80 years) who were impaired on the Verbal Story Recall Test either to the experimental group (EG) or the control group (CG). The EG underwent 6 months of VR memory training (VRMT) that involved auditory stimulation and VR experiences in path finding. The initial training phase lasted 3 months (3 auditory and 3 VR sessions every 2 weeks), and there was a booster training phase during the following 3 months (1 auditory and 1 VR session per week). The CG underwent equivalent face-to-face training sessions using music therapy. Both groups participated in social and creative and assisted-mobility activities. Neuropsychological and functional evaluations were performed at baseline, after the initial training phase, and after the booster training phase. Results.The EG showed significant improvements in memory tests, especially in long-term recall with an effect size of 0.7 and in several other aspects of cognition. In contrast, the CG showed progressive decline. Conclusions . The authors suggest that VRMT may improve memory function in elderly adults by enhancing focused attention.

The present study investigated the effects of left hemispatial neglect on two tasks activating the mental number line (MNL). Six patients with left neglect performed a mental number bisection task and a modified version of the Spatial Numerical Association of Response Codes (SNARC) task. Effects of left neglect were observed in the number bisection task, but not in the SNARC task. We argue that the dissociation between number bisection and SNARC resembles, in the representational space of the MNL, previously reported dissociations on neglect between explicit knowledge (assessed by direct tasks) and implicit knowledge (assessed by indirect tasks).