Linear Spatial-Numeric Associations Aid Memory for Single Numbers.

Memory for numbers improves with age. One source of this improvement may be learning linear spatial-numeric associations, but previous evidence for this hypothesis likely confounded memory span with quality of numerical magnitude representations and failed to distinguish spatial-numeric mappings from other numeric abilities, such as counting or number word-cardinality mapping. To obviate the influence of memory span on numerical memory, we examined 39 3- to 5-year-olds' ability to recall one spontaneously produced number (1-20) after a delay, and the relation between numeric recall (controlling for non-numeric recall) and quality of mapping between symbolic and non-symbolic quantities using number-line estimation, give-a-number estimation, and counting tasks. Consistent with previous reports, mapping of numerals to space, to discrete quantities, and to numbers in memory displayed a logarithmic-to-linear shift. Also, linearity of spatial-numeric mapping correlated strongly with multiple measures of numeric recall (percent correct and percent absolute error), even when controlling for age and non-numeric memory. Results suggest that linear spatial-numeric mappings may aid memory for number over and above children's other numeric skills.

Lifeguards: a forgotten aspect of drowning prevention.

An alarming number of drownings occur in lifeguarded swimming areas, where one might presume swimmers are protected from injury. One reason drownings occur in lifeguarded swimming areas is because lifeguard surveillance is a highly difficult task. Observational research suggests lifeguards are usually alert, but researchers also report egregious examples of inattention. We offer three strategies that have initial empirical support to reduce risk of drowning at lifeguarded swimming areas: (a) regular training to help lifeguards recognize they are vulnerable to drowning events and to raise their confidence; (b) regular practice via simulated emergency responses, and (c) addressing staff schedules so lifeguards can devote full attention to protecting swimmer safety while on duty.