1993-schneider.pdf: “Chess Expertise and Memory for Chess Positions in Children and Adults”, Wolfgang Schneider, Hans Gruber, Andreas Gold, Klaus Opwis (1993-12-01):
This paper presents a replication and extension of Chi′s (1978) classic study on chess expertise [“Knowledge structures and memory development”]. A major outcome of Chi′s research was that although adult novices had a better memory span than child experts, the children showed better memory for chess positions than the adults. The major goal of this study was to explore the effects of the following task characteristics on memory performance: (1) Familiarity with the constellation of chess pieces (i.e., meaningful versus random positions) and (2) familiarity with both the geometrical structure of the board and the form and color of chess pieces. The tasks presented to the four groups of subjects (i.e., child experts and novices, adult experts and novices) included memory for meaningful and random chess positions as well as memory for the location of wooden pieces of different forms on a board geometrically structured by circles, triangles, rhombuses, etc. (control task 1). Further, a digit span memory task was given (control task 2). The major assumption was that the superiority of experts should be greatest for the meaningful chess positions, somewhat reduced but still statistically-significant for the random positions, and nonsignificant for the board control task. Only age effects were expected for the digit span task. The results conformed to this pattern, showing that each type of knowledge contributed to the experts′ superior memory span for chess positions.
2009-karbach.pdf: “How useful is executive control training? Age differences in near and far transfer of task-switching training”, Julia Karbach, Jutta Kray (2009-10-14):
Although executive functions can be improved by training, little is known about the extent to which these training-related benefits can be transferred to other tasks, or whether this transfer can be modulated by the type of training. This study investigated lifespan changes in near transfer of task-switching training to structurally similar tasks and its modulation by verbal self-instructions and variable training, as well as far transfer to structurally dissimilar ‘executive’ tasks and fluid intelligence. Three age groups (8–10; 18–26; 62–76 years of age) were examined in a pretest-training-posttest design. We found near transfer of task-switching training in all age groups, especially in children and older adults. Near transfer was enhanced in adults and impaired in children when training tasks were variable. We also found substantial far transfer to other executive tasks and fluid intelligence in all age groups, pointing to the transfer of relatively general executive control abilities after training.
2009-rodriguezjimenez.pdf: “Differential dorsolateral prefrontal cortex activation during a verbal n-back task according to sensory modality”, Roberto Rodriguez-Jimenez, Cesar Avila, Cristina Garcia-Navarro, Alexandra Bagney, Ana Martinez de Aragon, Noelia Ventura-Campos, Isabel Martinez-Gras, Cristina Forn, Guillermo Ponce, Gabriel Rubio, Miguel Angel Jimenez-Arriero, Tomas Palomo (2009-12-14):
Functional neuroimaging studies carried out on healthy volunteers while performing different n-back tasks have shown a common pattern of bilateral frontoparietal activation, especially of the dorsolateral prefrontal cortex (DLPFC). Our objective was to use functional magnetic resonance imaging (fMRI) to compare the pattern of brain activation while performing two similar n-back tasks which differed in their presentation modality. Thirteen healthy volunteers completed a verbal 2-back task presenting auditory stimuli, and a similar 2-back task presenting visual stimuli. A conjunction analysis showed bilateral activation of frontoparietal areas including the DLPFC. The left DLPFC and the superior temporal gyrus showed a greater activation in the auditory than in the visual condition, whereas posterior brain regions and the anterior cingulate showed a greater activation during the visual than during the auditory task. Thus, brain areas involved in the visual and auditory versions of the n-back task showed an important overlap between them, reflecting the supramodal characteristics of working memory. However, the differences found between the two modalities should be considered in order to select the most appropriate task for future clinical studies. [Keywords: fMRI, Working memory, n-back task, Auditory, Visual, DLPFC]
2016-foroughi.pdf: “Placebo effects in cognitive training”, Cyrus K. Foroughi, Samuel S. Monfort, Martin Paczynski, Patrick E. McKnight, P. M. Greenwood (2016-07-05):
Placebo effects pose problems for some intervention studies, particularly those with no clearly identified mechanism. Cognitive training falls into that category, and yet the role of placebos in cognitive interventions has not yet been critically evaluated. Here, we show clear evidence of placebo effects after a brief cognitive training routine that led to substantial fluid intelligence gains. Our goal is to emphasize the importance of ruling out alternative explanations before attributing the effect to interventions. Based on our findings, we recommend that researchers account for placebo effects before claiming treatment effects.
Although a large body of research shows that general cognitive ability is heritable and stable in young adults, there is recent evidence that fluid intelligence can be heightened with cognitive training. Many researchers, however, have questioned the methodology of the cognitive-training studies reporting improvements in fluid intelligence: specifically, the role of placebo effects. W
e designed a procedure to intentionally induce a placebo effect via overt recruitment in an effort to evaluate the role of placebo effects in fluid intelligence gains from cognitive training. Individuals who self-selected into the placebo group by responding to a suggestive flyer showed improvements after a single, 1-h session of cognitive training that equates to a 5-point to 10-point increase on a standard IQ test. Controls responding to a non-suggestive flyer showed no improvement.
These findings provide an alternative explanation for effects observed in the cognitive-training literature and the brain-training industry, revealing the need to account for confounds in future research.
…We also observed differences between groups for scores on the Theories of Intelligence scale, which measures beliefs regarding the malleability of intelligence (34). The participants in the placebo group reported substantially higher scores on this index compared with controls [B = 14.96, SE = 1.93, t(48) = 7.75, p < 0.0001, d = 2.15], indicating a greater confidence that intelligence is malleable. These findings indicate that our manipulation via recruitment flyer produced statistically-significantly different groups with regard to expectancy. We did not detect differences in Need for Cognition scores (41) [B = 0.56, SE = 5.67, t(48) = 0.10, p = 0.922] (Figure 3). Together, these results support the interpretation that participants self-selected into groups based on differing expectations.
2020-ma.pdf: “Training and transfer effects of long-term memory retrieval training”, Xiaofeng Ma, Haobao Zhang, Xin Zhao, Aibao Zhou (2020-08-30):
Long-term memory retrieval ability and working memory can share attention control ability. Based on cognitive plasticity, a hypothesis that cognitive training could improve long-term memory retrieval efficiency and that this could transfer to retrieval involving working memory was proposed. 60 undergraduates were randomly assigned to a group of training and an active control group; all the participants completed the same tasks in the same order before and after the training, the tasks included a long-term memory retrieval access task, a intelligence test, a switching task, a working memory updating task, a response inhibition task and an interference control task. The statistics results indicate that cognitive training can improve long-term memory retrieval efficiency and has a transfer effect on working memory updating, interference control and switching ability, but not on response inhibition or intelligence. This reveal the plasticity of long-term memory retrieval and its influence on working memory.
2020-stojanoski.pdf: “Brain training habits are not associated with generalized benefits to cognition: An online study of over 1000 'brain trainers'”, Bobby Stojanoski, Conor J. Wild, Michael E. Battista, Emily S. Nichols, Adrian M. Owen (2020-09-24):
The foundational tenet of brain training is that general cognitive functioning can be enhanced by completing computerized games, a notion that is both intuitive and appealing. Moreover, there is strong incentive to improve our cognitive abilities, so much so that it has driven a billion-dollar industry. However, whether brain training can really produce these desired outcomes continues to be debated. This is, in part, because the literature is replete with studies that use ill-defined criteria for establishing transferable improvements to cognition, often using single training and outcome measures with small samples. To overcome these limitations, we conducted a large-scale online study to examine whether practices and beliefs about brain training are associated with better cognition. We recruited a diverse sample of over 1000 participants, who had been using an assortment of brain training programs for up to 5 years. Cognition was assessed using multiple tests that measure attention, reasoning, working memory and planning. We found no association between any measure of cognitive functioning and whether participants were currently ‘brain training’ or not, even for the most committed brain trainers. Duration of brain training also showed no relationship with any cognitive performance measure. This result was the same regardless of participant age, which brain training program they used, or whether they expected brain training to work. Our results pose a substantial challenge for ‘brain training’ programs that purport to improve general cognitive functioning among the general population.