TY  - JOUR
A1  - Reike, Dennis
A1  - Schwarz, Wolfgang
T1  - Aging effects on symbolic number comparison
BT  - no deceleration of numerical information retrieval but more conservative decision-making
JF  - Psychology and aging
N2  - Whereas many cognitive tasks show pronounced aging effects, even in healthy older adults, other tasks seem more resilient to aging. A small number of recent studies suggests that number comparison is possibly one of the abilities that remain unaltered across the life span. We investigated the ability to compare single-digit numbers in young (19-39 years; n = 39) and healthy older (65-79 years; n = 39) adults in considerable detail, analyzing accuracy as well as mean and variance of their response time, together with several other well-established hallmarks of numerical comparison. Using a recent comprehensive process model that parsimoniously accounts quantitatively for many aspects of number comparison (Reike & Schwarz, 2016), we address two fundamental problems in the comparison of older to young adults in numerical comparison tasks: (a) to adequately correct speed measures for different levels of accuracy (older participants were significantly more accurate than young participants), and (b) to distinguish between general sensory and motor slowing on the one hand, as opposed to a specific age-related decline in the efficiency to retrieve and compare numerical magnitude representations. Our results represent strong evidence that healthy older adults compare magnitudes as efficiently as young adults, when the measure of efficiency is uncontaminated by strategic speed-accuracy trade-offs and by sensory and motor stages that are not related to numerical comparison per se. At the same time, older adults aim at a significantly higher accuracy level (risk aversion), which necessarily prolongs processing time, and they also show the well-documented general decline in sensory and/or motor functions.
KW  - numerical comparison
KW  - cognitive aging effects
KW  - numerical distance effect
KW  - random walk model
KW  - speed-accuracy trade-off
Y1  - 2019
U6  - https://doi.org/10.1037/pag0000272
SN  - 0882-7974
SN  - 1939-1498
VL  - 34
IS  - 1
SP  - 4
EP  - 16
PB  - American Psychological Association
CY  - Washington
ER  - 
TY  - JOUR
A1  - Reike, Dennis
A1  - Schwarz, Wolfgang
T1  - One Model Fits All: Explaining Many Aspects of Number Comparison Within a Single Coherent Model-A Random Walk Account
JF  - Journal of experimental psychology : Learning, memory, and cognition
N2  - The time required to determine the larger of 2 digits decreases with their numerical distance, and, for a given distance, increases with their magnitude (Moyer & Landauer, 1967). One detailed quantitative framework to account for these effects is provided by random walk models. These chronometric models describe how number-related noisy partial evidence is accumulated over time; they assume that the drift rate of this stochastic process varies lawfully with the numerical magnitude of the digits presented. In a complete paired number comparison design we obtained saccadic choice responses of 43 participants, and analyzed mean saccadic latency, error rate, and the standard deviation of saccadic latency for each of the 72 digit pairs; we also obtained mean error latency for each numerical distance. Using only a small set of meaningfully interpretable parameters, we describe a variant of random walk models that accounts in considerable quantitative detail for many facets of our data, including previously untested aspects of latency standard deviation and error latencies. However, different from standard assumptions often made in random walk models, this account required that the distributions of step sizes of the induced random walks are asymmetric. We discuss how our findings can help in interpreting complex findings (e.g., conflicting speed vs. accuracy trends) in applied studies which use number comparison as a well-established diagnostic tool. Finally, we also describe a novel effect in number comparison, the decrease of saccadic response amplitude with numerical distance, and suggest an interpretation using the conceptual framework of random walk models.
KW  - numerical distance effect
KW  - random walk models
KW  - error latency
KW  - saccadic latency
KW  - saccadic amplitude
Y1  - 2016
U6  - https://doi.org/10.1037/xlm0000287
SN  - 0278-7393
SN  - 1939-1285
VL  - 42
SP  - 1957
EP  - 1971
PB  - American Psychological Association
CY  - Washington
ER  -