Over the past several decades, empirical and theoretical work has focused on the question of whether it is possible to purposefully improve cognitive functioning through behavioral interventions. Accordingly, a field is emerging around cognitive training, be it through executive function training, video game play, music training, aerobic exercise, or mindfulness meditation. One concern that has been raised regarding the results of this field centers on the potential impact of participants' expectations. Suggestions have been raised that participants may, at least in some cases, show improvements in performance because they expect to improve, rather than because of any mechanisms inherent in the behavioral interventions per se. The present paper discusses the latest views on expectations and the new methodological challenges they raise when considering the effectiveness of behavioral interventions on human behavior, and in particular cognition. Keywords Expectations . Cognitive training . Placebo . Associative learning . Bayesian combination There is currently a great deal of interest in the possibility that human cognitive function can be purposefully improved via dedicated long-term behavioral training (Strobach and Karbach 2016). Indeed, the past few decades have seen an explosion of work examining the potential for behavioral training to positively impact a host of cognitive functions, including fluid intelligence (Au et al. 2015), working memory (Nutley and Söderqvist 2017), spatial thinking (Uttal et al. 2013a), executive function (Titz and Karbach 2014), and selective attention (Parsons et al. 2016).Like all nascent scientific domains, much of the research to date has focused on basic science questions. Such investigations include, for instance, examinations of the core mechanisms underlying cognitive change and how these could be deliberately manipulated to produce intended outcomes (Bavelier et al. 2010;Deveau et al. 2015). Yet, the obvious real-world significance of successful cognitive enhancement has also prompted a substantial amount of work probing possible avenues for translation. Many distinct populations of individuals could potentially realize significant benefits from effective means of cognitive enhancement, especially those showing deficits in cognitive functioning for reasons related to various disorders, damage, disease, and/or age-related degradation (Biagianti and Vinogradov 2013;Mahncke et al. 2006;Ross et al. 2017). Even among those individuals within the normal range of cognitive functioning, cognitive enhancement could be advantageous in a host of real-world situations, from law enforcement, to piloting, to athletics, to academic pursuits (McKinley et al. 2011;Rosser et al. 2007;Uttal et al. 2013a;Uttal et al. 2013b).While the results of numerous individual studies and metaanalyses have provided reason for optimism that cognitive functions can be enhanced via some forms of behavioral training, significant debate in the field still persists (Green et al.Daphné Bavelier and C. Shawn Gree...

Purpose To describe two new stereoacuity tests: the eRDS v6 stereotest, a global dynamic random dot stereogram (dRDS) test, and the Vivid Vision Stereo Test version 2 (VV), a local or “contour” stereotest for virtual reality (VR) headsets; and to evaluate the tests’ reliability, validity compared to a dRDS standard, and learning effects. Methods Sixty-four subjects passed a battery of stereotests, including perceiving depth from RDS. Validity was evaluated relative to a tablet-based dRDS reference test, ASTEROID. Reliability and learning effects were assessed over six sessions. Results eRDS v6 was effective at measuring small thresholds (<10 arcsec) and had a moderate correlation (0.48) with ASTEROID. Across the six sessions, test-retest reliability was good, varying from 0.84 to 0.91, but learning occurred across the first three sessions. VV did not measure stereoacuities below 15 arcsec. It had a weak correlation with ASTEROID (0.27), and test-retest reliability was poor to moderate, varying from 0.35 to 0.74; however, no learning occurred between sessions. Conclusions eRDS v6 is precise and reliable but shows learning effects. If repeated three times at baseline, this test is well suited as an outcome measure for testing interventions. VV is less precise, but it is easy and rapid and shows no learning. It may be useful for testing interventions in patients who have no global stereopsis. Translational Relevance eRDS v6 is well suited as an outcome measure to evaluate treatments that improve adult stereodepth perception. VV can be considered for screening patient with compromised stereovision.