The Odd–Even Effect in Sudoku Puzzles: Effects of Working Memory, Aging, and Experience

Abstract

The odd–even effect in numerical processing has been explained as the easier processing of even numbers compared with odd numbers. We investigated this effect in Sudoku puzzles, a reasoning problem that uses numbers but does not require arithmetic operations. Specifically, we asked whether the odd–even effect occurred with Sudoku puzzles and whether individual differences in working memory (WM), aging, and experience with Sudoku modulated this effect. We manipulated the presence of odd and even numbers in Sudoku puzzles, measured WM with the Wisconsin Card Sorting Test and backward digit span task, tested older and younger adults, and collected Sudoku experience frequency. Performance on Sudoku was more accurate for even puzzles than odd ones. Younger, experienced, and higher-WM participants were more accurate on Sudoku, but these individual difference variables did not interact with the odd–even effect. Odd numbers may impose more cognitive load than even numbers, but future research is needed to examine how age, experience, or WM may influence the odd–even effect.

The relationship between the frequency of number‐puzzle use and baseline cognitive function in a large online sample of adults aged 50 and over

“…However, the frequency association was less linear.The analysis identified benefit across several cognitive domains including episodic memory, spatial working memory, attention, processing speed, and executive function. This correlates with previous studies, which have also indicated associations with working memory, problem solving, and attention [7][8][9][10]. Combined, the literature appears to suggest a global cognitive impact, which is not restricted to a specific cognitive domain.…”

“…005, d = 0.07 and 0.09). This correlates with previous studies, which have also indicated associations with working memory, problem solving, and attention [7][8][9][10]. Analysis of data from the four PCTB measures showed consistent superior performance, with effect sizes ranging from d = 0.17 to d = 0.47.…”

“…The evolution of the internet and its place in society has opened doors for different types of cognitive training and brain-stimulating activities, which are available to individuals online 24 hours a day. [7][8][9] Paulraj et al investigated the relationship between regular use of puzzles and performance on the Wisconsin Card-Sorting Test (WCST) in healthy adults, showing that regular sudoku and/or crossword use was associated with better executive function. This complies with the simple concept of "use it or lose it," which suggests that the brain must continue to be used in a way that it is stimulated and challenged throughout life.…”

“…The value of number-puzzle use in older adults who later develop dementia has previously been shown in studies in which older adults who regularly complete puzzles perform at a higher level on cognitive tasks compared with those who do not, 6 and a number of additional studies have reported benefit to working memory, attention, and accuracy in cognitive tests. [7][8][9] Paulraj et al investigated the relationship between regular use of puzzles and performance on the Wisconsin Card-Sorting Test (WCST) in healthy adults, showing that regular sudoku and/or crossword use was associated with better executive function. 10 Overall higher frequency puzzle users were able to complete more task categories, which suggests superior cognitive function and problemsolving skills.…”

Associations between cognitively stimulating leisure activities, cognitive function and age‐related cognitive decline

“…Few studies have examined the cognitive demands associated with completing Sudoku puzzles or its potential protective factor as a cognitively stimulating activity for delaying cognitive decline. A comparable study did, however, report an association between accuracy on Sudoku puzzles and working memory, as measured by the Wisconsin Card Sorting Test and Backwards Digit Span Task (Chang and Gibson, ). Authors of a further study suggest that deactivation in the posterior cingulate cortex and precuneus found during Sudoku completion is likely due to reallocation of cognitive resources required during the task including for working memory, preparatory attention, target detection and monitoring of response accuracy (Jin et al ., ).…”