Aging and the number sense: preserved basic non-symbolic numerical processing and enhanced basic symbolic processing

Abstract

Aging often leads to general cognitive decline in domains such as memory and attention. The effect of aging on numerical cognition, particularly on foundational numerical skills known as the number sense, is not well-known. Early research focused on the effect of aging on arithmetic. Recent studies have begun to investigate the impact of healthy aging on basic numerical skills, but focused on non-symbolic quantity discrimination alone. Moreover, contradictory findings have emerged. The current study aimed to further investigate the impact of aging on basic non-symbolic and symbolic numerical skills. A group of 25 younger (18–25) and 25 older adults (60–77) participated in non-symbolic and symbolic numerical comparison tasks. Mathematical and spelling abilities were also measured. Results showed that aging had no effect on foundational non-symbolic numerical skills, as both groups performed similarly [RTs, accuracy and Weber fractions (w)]. All participants showed decreased non-symbolic acuity (accuracy and w) in trials requiring inhibition. However, aging appears to be associated with a greater decline in discrimination speed in such trials. Furthermore, aging seems to have a positive impact on mathematical ability and basic symbolic numerical processing, as older participants attained significantly higher mathematical achievement scores, and performed significantly better on the symbolic comparison task than younger participants. The findings suggest that aging and its lifetime exposure to numbers may lead to better mathematical achievement and stronger basic symbolic numerical skills. Our results further support the observation that basic non-symbolic numerical skills are resilient to aging, but that aging may exacerbate poorer performance on trials requiring inhibitory processes. These findings lend further support to the notion that preserved basic numerical skills in aging may reflect the preservation of an innate, primitive, and embedded number sense.

The measurement of approximate number system acuity across the lifespan is compromised by congruency effects

“…The current study therefore highlights the necessity for researchers to seriously consider the influence of convex hull on numerosity discrimination when exploring its relationship with maths achievement (Clayton et al, 2015;Gilmore et al, 2016). Moreover, the results raise questions regarding previous conclusions of declined ANS acuity in ageing (Halberda et al, 2012), and whether dot-size congruency can fully account for these effects (Cappelletti et al, 2014;Norris et al, 2015). Future research must investigate whether ANS acuity is declined in ageing when convex hull is systematically controlled:…”

Dot Display Affects Approximate Number System Acuity and Relationships with Mathematical Achievement and Inhibitory Control

“…Although the mathematical achievement task used in the current study has been applied in similar research [ 9 , 38 ], our mathematical achievement index and those of other studies may benefit from the inclusion of further mathematical problems (e.g. division).…”

“…A timed, paper-based calculation task provided a mathematical achievement index for each participant [ 38 ]. The task consisted of addition, subtraction, and multiplication questions, in which participants were asked to answer as many questions as possible by writing their answers after each arithmetical problem.…”

The Relationship between Cognitive Reserve and Math Abilities

“…Moreover, the only deficit found, poor numerosity discrimination, was likely to reflect an older persons impoverished inhibitory processes rather than an authentic numerical impairment. Norris et al ( 2015 ) even showed a positive impact of age in both basic symbolic numerical processing and mathematical abilities.…”