Open AccessFeature PaperArticle
When Irrational Biases Are Smart: A Fuzzy-Trace Theory of Complex Decision Making
J. Intell. 2018, 6(2), 29; https://doi.org/10.3390/jintelligence6020029 -
Abstract
I take a decision-making approach to consider ways of addressing the “unresolved and dramatic problems in the world”. Traditional approaches to good decision-making are reviewed. These approaches reduce complex decisions to tradeoffs between magnitudes of probabilities, and outcomes in which the quantity and
[...] Read more.
I take a decision-making approach to consider ways of addressing the “unresolved and dramatic problems in the world”. Traditional approaches to good decision-making are reviewed. These approaches reduce complex decisions to tradeoffs between magnitudes of probabilities, and outcomes in which the quantity and precision of information are key to making good decisions. I discuss a contrasting framework, called “fuzzy-trace theory”, which emphasizes understanding the simple gist of options and applying core social and moral values. Importantly, the tendency to rely on meaningful but simple gist increases from childhood to adulthood (or, in adulthood, as people gain experience in a domain), so that specific irrational biases grow with knowledge and experience. As predicted theoretically, these violations of rationality in the traditional sense are associated empirically with healthier and more adaptive outcomes. Thus, interventions that help decision makers understand the essential gist of their options and how it connects to core values are practical approaches to reducing “unresolved and dramatic problems in the world” one decision at a time. Full article
Open AccessFeature PaperArticle
Relationships between Personality and Cognitive Ability: A Facet-Level Analysis
J. Intell. 2018, 6(2), 28; https://doi.org/10.3390/jintelligence6020028 -
Abstract
A growing body of research supports the notion that cognitive abilities and personality are systematically related. However, this research has focused largely on global personality dimensions and single—often equally global—markers of cognitive ability. The present study offers a more fine-grained perspective. Specifically, it
[...] Read more.
A growing body of research supports the notion that cognitive abilities and personality are systematically related. However, this research has focused largely on global personality dimensions and single—often equally global—markers of cognitive ability. The present study offers a more fine-grained perspective. Specifically, it is one of the first studies to comprehensively investigate the associations between both fluid and crystallized intelligence with Big Five personality domains as well as their facets. Based on a heterogeneous sample of the adult population in Germany (N = 365), our study yielded three key findings. First, personality was more strongly related to crystallized intelligence than to fluid intelligence. This applied both to the total variance explained and to the effect sizes of most of the Big Five domains and facets. Second, facets explained a larger share of variance in both crystallized and fluid intelligence than did domains. Third, the associations of different facets of the same domain with cognitive ability differed, often quite markedly. These differential associations may substantially reduce—or even suppress—the domain-level associations. Our findings clearly attest to the added value of a facet-level perspective on the personality–cognitive ability interface. We discuss how such a fine-grained perspective can further theoretical understanding and enhance prediction. Full article
Figures

Figure 1

Open AccessFeature PaperArticle
Personality and Intelligence Interact in the Prediction of Academic Achievement
J. Intell. 2018, 6(2), 27; https://doi.org/10.3390/jintelligence6020027 -
Abstract
Personality predicts academic achievement above and beyond intelligence. However, studies investigating the possible interaction effects between personality and intelligence when predicting academic achievement are scarce, as is the separate investigation of broad personality factors versus narrow personality facets in this context. Two studies
[...] Read more.
Personality predicts academic achievement above and beyond intelligence. However, studies investigating the possible interaction effects between personality and intelligence when predicting academic achievement are scarce, as is the separate investigation of broad personality factors versus narrow personality facets in this context. Two studies with 11th grade students (Study 1: N = 421; Study 2: N = 243) were conducted to close this research gap. The students completed the Intelligence-Structure-Test 2000 R measuring general reasoning ability, and a well-established personality inventory based on the Five Factor Model. Academic achievement was operationalized via Grade Point Average. Using hierarchical regression and moderation analyses, Study 1 revealed that Conscientiousness interacted with intelligence when predicting academic achievement: there was a stronger association between intelligence and academic achievement when students scored higher on the Conscientiousness scale. Study 2 confirmed the findings from Study 1 and also found a moderation effect of Neuroticism (stronger association between intelligence and academic achievement with lower values on the Neuroticism scale). Analyses at the facet level revealed much more differentiated results than did analyses at the domain level, suggesting that investigating personality facets should be preferred over investigating personality domains when predicting academic achievement. Full article
Figures

Figure 1

Open AccessFeature PaperReview
Low Correlations between Intelligence and Big Five Personality Traits: Need to Broaden the Domain of Personality
J. Intell. 2018, 6(2), 26; https://doi.org/10.3390/jintelligence6020026 -
Abstract
The correlations between the measures of cognitive abilities and personality traits are known to be low. Our data based on the popular Big Five model of intelligence show that the highest correlations (up to r = 0.30) tend to occur with the Openness
[...] Read more.
The correlations between the measures of cognitive abilities and personality traits are known to be low. Our data based on the popular Big Five model of intelligence show that the highest correlations (up to r = 0.30) tend to occur with the Openness to Experience. Some recent developments in the studies of intelligence (e.g., emotional intelligence, complex problem solving and economic games) indicate that this link may become stronger in future. Furthermore, our studies of the processes in the “no-man’s-land” between intelligence and personality suggest that the non-cognitive constructs are correlated with both. These include the measures of social conservatism and self-beliefs. Importantly, the Big Five measures do not tap into either the dark traits associated with social conservatism or self-beliefs that are known to be good predictors of academic achievement. This paper argues that the personality domain should be broadened to include new constructs that have not been captured by the lexical approach employed in the development of the Big Five model. Furthermore, since the measures of confidence have the highest correlation with cognitive performance, we suggest that the trait of confidence may be a driver that leads to the separation of fluid and crystallized intelligence during development. Full article
Open AccessFeature PaperCommentary
How to Think Rationally about World Problems
J. Intell. 2018, 6(2), 25; https://doi.org/10.3390/jintelligence6020025 -
Abstract
I agree with the target essay that psychology has something to offer in helping to address societal problems. Intelligence has helped meliorate some social problems throughout history, including the period of time that is covered by the Flynn effect, but I agree with
[...] Read more.
I agree with the target essay that psychology has something to offer in helping to address societal problems. Intelligence has helped meliorate some social problems throughout history, including the period of time that is covered by the Flynn effect, but I agree with Sternberg that other psychological characteristics may be contributing as well, particularly increases in rationality. I also believe that increasing human rationality could have a variety of positive societal affects at levels somewhat smaller in grain size than the societal problems that Sternberg focuses on. Some of the societal problems that Sternberg lists, however, I do not think would be remedied by increases in rationality, intelligence, or wisdom, because remedy might be the wrong word in the context of these issues. Issues such as how much inequality of income to tolerate, how much pollution to tolerate, and how much we should sacrifice economic growth for potential future changes in global temperature represent issues of clashing values, not the inability to process information, nor the lack of information, nor the failure to show wisdom. Full article
Open AccessFeature PaperArticle
A Tempest in A Ladle: The Debate about the Roles of General and Specific Abilities in Predicting Important Outcomes
J. Intell. 2018, 6(2), 24; https://doi.org/10.3390/jintelligence6020024 -
Abstract
The debate about the roles of general and specific abilities in predicting important outcomes is a tempest in a ladle because we cannot measure abilities without also measuring skills. Skills always develop through exposure, are specific rather than general, and are executed using
[...] Read more.
The debate about the roles of general and specific abilities in predicting important outcomes is a tempest in a ladle because we cannot measure abilities without also measuring skills. Skills always develop through exposure, are specific rather than general, and are executed using different strategies by different people, thus tapping into varied specific abilities. Relative predictive validities of measurement formats depend on the purpose: the more general and long-term the purpose, the better the more general measure. The more specific and immediate the purpose, the better the closely related specific measure. Full article
Open AccessArticle
Individual Mental Abiities vs. the World’s Problems
J. Intell. 2018, 6(2), 23; https://doi.org/10.3390/jintelligence6020023 -
Abstract
The major problems in the world today are problems of government or the lack of it. Thus, the relevant parts of intelligence are those that make for good citizenship, such as supporting the best candidates and policies. I argue that dispositions, as well
[...] Read more.
The major problems in the world today are problems of government or the lack of it. Thus, the relevant parts of intelligence are those that make for good citizenship, such as supporting the best candidates and policies. I argue that dispositions, as well as capacities, are part of intelligence, and that some dispositions are the ones most crucial for citizenship, particularly the disposition to engage in actively open-minded thinking (AOT) and to apply it as a standard for the evaluation of the qualifications of authorities and leaders. AOT is a general prescriptive theory that applies to all thinking. It affects the aptness of conclusions and the accuracy of confidence judgments, and it reduces overconfidence when extreme confidence is not warranted. AOT may be affected by different factors from those that affect other components of intelligence and thus may undergo different changes over time. Whatever has happened in the past, we need more of it now. Full article
Open AccessFeature PaperPerspective
The Strengths of Wisdom Provide Unique Contributions to Improved Leadership, Sustainability, Inequality, Gross National Happiness, and Civic Discourse in the Face of Contemporary World Problems
J. Intell. 2018, 6(2), 22; https://doi.org/10.3390/jintelligence6020022 -
Abstract
We present evidence for the strengths of the intellectual virtues that philosophers and behavioral scientists characterize as key cognitive elements of wisdom. Wisdom has been of centuries-long interest for philosophical scholarship, but relative to intelligence largely neglected in public discourse on educational science,
[...] Read more.
We present evidence for the strengths of the intellectual virtues that philosophers and behavioral scientists characterize as key cognitive elements of wisdom. Wisdom has been of centuries-long interest for philosophical scholarship, but relative to intelligence largely neglected in public discourse on educational science, public policy, and societal well-being. Wise reasoning characteristics include intellectual humility, recognition of uncertainty, consideration of diverse viewpoints, and an attempt to integrate these viewpoints. Emerging scholarship on these features of wisdom suggest that they uniquely contribute to societal well-being, improve leadership, shed light on societal inequality, promote cooperation in Public Goods Games and reduce political polarization and intergroup-hostility. We review empirical evidence about macro-cultural, ecological, situational, and person-level processes facilitating and inhibiting wisdom in daily life. Based on this evidence, we speculate about ways to foster wisdom in education, organizations, and institutions. Full article
Figures

Figure 1

Open AccessFeature PaperArticle
Creativity as a Stepping Stone toward a Brighter Future
J. Intell. 2018, 6(2), 21; https://doi.org/10.3390/jintelligence6020021 -
Abstract
If IQs continue to rise over generation, why has the world been unable to solve basic recurrent problems? This paper argues that creativity, which is overlooked in IQ tests and showing no signs of a similar increase, may be part of the reason
[...] Read more.
If IQs continue to rise over generation, why has the world been unable to solve basic recurrent problems? This paper argues that creativity, which is overlooked in IQ tests and showing no signs of a similar increase, may be part of the reason of why the Flynn Effect has not led to a better world. Creativity’s predictive power for traditional positive outcomes, such as school or work performance, is significant but slight. However, there are other ways that creativity can help to make a better world. Two exemplar ways that are discussed in this paper are how creativity can (a) help people lead happier and more meaningful lives and (b) focus a spotlight on talented members of underrepresented groups who are overlooked by traditional measures. Both of these directions can lead to a world that is better equipped to solve larger issues. Full article
Open AccessArticle
Evaluating an Automated Number Series Item Generator Using Linear Logistic Test Models
J. Intell. 2018, 6(2), 20; https://doi.org/10.3390/jintelligence6020020 -
Abstract
This study investigates the item properties of a newly developed Automatic Number Series Item Generator (ANSIG). The foundation of the ANSIG is based on five hypothesised cognitive operators. Thirteen item models were developed using the numGen R package and eleven were evaluated in
[...] Read more.
This study investigates the item properties of a newly developed Automatic Number Series Item Generator (ANSIG). The foundation of the ANSIG is based on five hypothesised cognitive operators. Thirteen item models were developed using the numGen R package and eleven were evaluated in this study. The 16-item ICAR (International Cognitive Ability Resource1) short form ability test was used to evaluate construct validity. The Rasch Model and two Linear Logistic Test Model(s) (LLTM) were employed to estimate and predict the item parameters. Results indicate that a single factor determines the performance on tests composed of items generated by the ANSIG. Under the LLTM approach, all the cognitive operators were significant predictors of item difficulty. Moderate to high correlations were evident between the number series items and the ICAR test scores, with high correlation found for the ICAR Letter-Numeric-Series type items, suggesting adequate nomothetic span. Extended cognitive research is, nevertheless, essential for the automatic generation of an item pool with predictable psychometric properties. Full article
Figures

Figure 1

Open AccessArticle
Social-Demographic Indicators, Cognitive Ability, Personality Traits, and Region as Independent Predictors of Income: Findings from the UK Household Longitudinal Study (UKHLS)
J. Intell. 2018, 6(2), 19; https://doi.org/10.3390/jintelligence6020019 -
Abstract
This paper reports on a longitudinal study of over 12,000 people based on the UK Household Longitudinal Study data. We were interested in their monthly income (as the criterion variable) as it related to their gender, age, education, occupation, personality, intelligence, and region
[...] Read more.
This paper reports on a longitudinal study of over 12,000 people based on the UK Household Longitudinal Study data. We were interested in their monthly income (as the criterion variable) as it related to their gender, age, education, occupation, personality, intelligence, and region where they lived (as the predictor variables). Correlations showed that, after occupation and education, gender and cognitive ability (particularly numeric ability) were the strongest correlates of income. Hierarchical regressions showed that age and gender accounted for 9% of the variance, intelligence and personality added another 5%, and education and occupation added a further 15%, while region added a further 1%. All four models were statistically significant (p < 0.001). The study suggests that, in future research of this kind on the personal correlates of income, social-demographic, psychological, and regional factors all need to be considered. Limitations are acknowledged. Full article
Open AccessCommentary
Intellectual Brilliance and Presidential Performance: Why Pure Intelligence (or Openness) Doesn’t Suffice
J. Intell. 2018, 6(2), 18; https://doi.org/10.3390/jintelligence6020018 -
Abstract
In recent years it has become popular on the internet to debate the IQ of the incumbent president of the United States. Yet, these controversies (and hoaxes) presume that IQ has some relevance to understanding the president’s actual performance as the nation’s leader.
[...] Read more.
In recent years it has become popular on the internet to debate the IQ of the incumbent president of the United States. Yet, these controversies (and hoaxes) presume that IQ has some relevance to understanding the president’s actual performance as the nation’s leader. This assumption is examined by reviewing the empirical research on the intelligence–performance association in political leadership, with a special focus on U.S. presidents. The review starts by discussing at-a-distance assessment techniques, a method that has yielded reliable and valid measures of IQ, Intellectual Brilliance, and Openness to Experience; three correlated even if separable concepts. The discussion then turns to the reliable and valid measurement of presidential performance—or “greatness”—via successive surveys of hundreds of experts. These two lines of research then converged on the emergence of a six-predictor equation, in which Intellectual Brilliance plays a major role, to the exclusion of both IQ and Openness. The greatest presidents are those who feature wide interests, and who are artistic, inventive, curious, intelligent, sophisticated, complicated, insightful, wise, and idealistic (but who are far from being either dull or commonplace). These are the personal traits we should look for in the person who occupies the nation’s highest office if we seek someone most likely to solve the urgent problems of today and tomorrow. Full article
Open AccessEditorial
On the Importance of Intraindividual Variability in Cognitive Development
J. Intell. 2018, 6(2), 17; https://doi.org/10.3390/jintelligence6020017 -
Abstract
Developmental cognitive psychology (as well as cognitive psychology in general) has a long-standing tradition to ignore all variations other than age, as if individual variations were only measurement error or noise[...] Full article
Open AccessArticle
Intra-Individual Variability from a Lifespan Perspective: A Comparison of Latency and Accuracy Measures
J. Intell. 2018, 6(1), 16; https://doi.org/10.3390/jintelligence6010016 -
Abstract
Within-task variability across trials (intra-individual variability (IIV)) has been mainly studied using latency measures but rarely with accuracy measures. The aim of the Geneva Variability Study was to examine IIV in both latency and accuracy measures of cognitive performance across the lifespan, administering
[...] Read more.
Within-task variability across trials (intra-individual variability (IIV)) has been mainly studied using latency measures but rarely with accuracy measures. The aim of the Geneva Variability Study was to examine IIV in both latency and accuracy measures of cognitive performance across the lifespan, administering the same tasks to children, younger adults, and older adults. Six processing speed tasks (Response Time (RT) tasks, 8 conditions) and two working memory tasks scored in terms of the number of correct responses (Working Memory (WM)—verbal and visuo-spatial, 6 conditions), as well as control tasks, were administered to over 500 individuals distributed across the three age periods. The main questions were whether age differences in IIV would vary throughout the lifespan according (i) to the type of measure used (RTs vs. accuracy); and (ii) to task complexity. The objective of this paper was to present the general experimental design and to provide an essentially descriptive picture of the results. For all experimental tasks, IIV was estimated using intra-individual standard deviation (iSDr), controlling for the individual level (mean) of performance and for potential practice effects. As concerns RTs, and in conformity with a majority of the literature, younger adults were less variable than both children and older adults, and the young children were often the most variable. In contrast, IIV in the WM accuracy scores pointed to different age trends—age effects were either not observed or, when found, they indicated that younger adults were the more variable group. Overall, the findings suggest that IIV provides complementary information to that based on a mean performance, and that the relation of IIV to cognitive development depends on the type of measure used. Full article
Open AccessArticle
Cognitive Development Is a Reconstruction Process that May Follow Different Pathways: The Case of Number
J. Intell. 2018, 6(1), 15; https://doi.org/10.3390/jintelligence6010015 -
Abstract
Some cognitive functions shared by humans and certain animals were acquired early in the course of phylogeny and, in humans, are operational in their primitive form shortly after birth. This is the case for the quantification of discrete objects. The further phylogenetic evolution
[...] Read more.
Some cognitive functions shared by humans and certain animals were acquired early in the course of phylogeny and, in humans, are operational in their primitive form shortly after birth. This is the case for the quantification of discrete objects. The further phylogenetic evolution of the human brain allows such functions to be reconstructed in a much more sophisticated way during child development. Certain functional characteristics of the brain (plasticity, multiple cognitive processes involved in the same response, interactions, and substitution relationships between those processes) provide degrees of freedom that open up the possibility of different pathways of reconstruction. The within- and between-individual variability of these developmental pathways offers an original window on the dynamics of development. Here, I will illustrate this theoretical approach to cognitive development—which can be called “reconstructivist” and “pluralistic”—using children’s construction of number as an example. Full article
Open AccessArticle
A Solution to the Measurement Problem in the Idiographic Approach Using Computer Adaptive Practicing
J. Intell. 2018, 6(1), 14; https://doi.org/10.3390/jintelligence6010014 -
Abstract
Molenaar’s manifesto on psychology as idiographic science (Molenaar, 2004) brought the N=1 times series perspective firmly to the attention of developmental scientists. The rich intraindividual variation in complex developmental processes requires the study of these processes at the level of the
[...] Read more.
Molenaar’s manifesto on psychology as idiographic science (Molenaar, 2004) brought the N=1 times series perspective firmly to the attention of developmental scientists. The rich intraindividual variation in complex developmental processes requires the study of these processes at the level of the individual. Yet, the idiographic approach is all but easy in practical research. One major limitation is the collection of short interval times series of high quality data on developmental processes. In this paper, we present a novel measurement approach to this problem. We developed an online practice and monitoring system which is now used by thousands of Dutch primary school children on a daily or weekly basis, providing a new window on cognitive development. We will introduce the origin of this new instrument, called Math Garden, explain its setup, and present and discuss ways to analyze children’s individual developmental pathways. Full article
Figures

Figure 1

Open AccessArticle
Intraindividual Variability in Inhibition and Prospective Memory in Healthy Older Adults: Insights from Response Regularity and Rapidity
J. Intell. 2018, 6(1), 13; https://doi.org/10.3390/jintelligence6010013 -
Abstract
Successful prospective memory (PM) performance relies on executive functions, including inhibition. However, PM and inhibition are usually assessed in separate tasks, and analytically the focus is either on group differences or at most on interindividual differences. Conjoint measures of PM and inhibition performance
[...] Read more.
Successful prospective memory (PM) performance relies on executive functions, including inhibition. However, PM and inhibition are usually assessed in separate tasks, and analytically the focus is either on group differences or at most on interindividual differences. Conjoint measures of PM and inhibition performance that take into account intraindividual variability (IIV) are thus missing. In the present study, we assessed healthy older adults’ level of performance and IIV in both inhibition and PM using a classical Go/NoGo task. We also created a prospective Go/NoGo version that embeds a PM component into the task. Using dynamic structural equation modeling, we assessed the joint effects of mean level (μ), an indicator of amplitude of fluctuations in IIV (or net IIV; intraindividual standard deviation, iSD), and an indicator of time dependency in IIV (the autoregressive parameter ϕ) in reaction times (RTs) on inhibition and PM performance. Results indicate that higher inhibition failure, but not IIV, predicted PM errors, corroborating the current literature on the involvement of prepotent response inhibition in PM processes. In turn, fastest RT latency (μ) and increased net IIV (iSD) were consistently associated with prepotent response inhibition failure, while coherence in RT pattern (ϕ) was beneficial to inhibition performance when the task was novel. Time-dependent IIV (ϕ) appears to reflect an adaptive exploration of strategies to attain optimal performance, whereas increased net IIV (iSD) may indicate inefficient sustained cognitive processes when performance is high. We discuss trade-off processes between competing tasks. Full article
Figures

Figure 1

Open AccessArticle
Intraindividual Variability across Neuropsychological Tests: Dispersion and Disengaged Lifestyle Increase Risk for Alzheimer’s Disease
J. Intell. 2018, 6(1), 12; https://doi.org/10.3390/jintelligence6010012 -
Abstract
Objective: Increased intraindividual variability (IIV) in function has been linked to various age-related outcomes including cognitive decline and dementia. Most studies have operationalized IIV as fluctuations across trials (e.g., response latencies) for a single task, with comparatively few studies examining variability across
[...] Read more.
Objective: Increased intraindividual variability (IIV) in function has been linked to various age-related outcomes including cognitive decline and dementia. Most studies have operationalized IIV as fluctuations across trials (e.g., response latencies) for a single task, with comparatively few studies examining variability across multiple tasks for a given individual. In the present study, we derive a multivariable operationalization of dispersion across a broad profile of neuropsychological measures and use this index along with degree of engaged lifestyle to predict risk of cognitive impairment. Participants and Methods: Participants (n = 60) were community-dwelling older adults aged 65+ years (M = 74.1, SD = 6.5) participating in a cross-sectional investigation of risk factors for amnestic mild cognitive impairment (a-MCI) and probable Alzheimer’s Disease (AD). Participants were classified into three subgroups based on test performance and clinical judgement. Healthy controls (n = 30) scored better than −1 SD relative to existing norms on all classification measures, in the absence of memory complaints or functional impairments. The a-MCI group (n = 23) had self- or informant-reported memory complaints and scored 1 SD or more below the mean for at least one memory task while scoring better than 1 SD below the mean for all other cognitive domains, in the absence of functional impairments. The AD group (n = 7) scored at least 2 SD below the mean for two cognitive domains (including memory) with impairments in functioning. Measures spanned a range of cognitive domains (episodic memory, executive function, language), with the derived dispersion estimates reflecting variability across an individual’s neuropsychological profile relative to the group average. Further, an Activities Lifestyle Questionnaire, indexing social, cognitive, and physical behaviors, was administered to assess the protective benefits of engaged lifestyle. Results: Multinomial logistic regression models examined the risk of being classified as a-MCI or AD as a function of increased dispersion, (dis)engaged lifestyle, and their interaction. Greater dispersion was associated with an increased likelihood of being classified with AD, with protective engaged-lifestyle benefits apparent for a-MCI individuals only. Conclusion: As a measure of IIV, dispersion across neuropsychological profiles holds promise for the detection of cognitive impairment. Full article
Figures

Figure 1a

Open AccessArticle
Enhancing Intelligence: From the Group to the Individual
J. Intell. 2018, 6(1), 11; https://doi.org/10.3390/jintelligence6010011 -
Abstract
Research aimed at testing whether short-term training programs can enhance intelligence is mainly concentrated on behavior. Expected positive effects are found sometimes, but the evidence is far from conclusive. It is assumed that training must evoke changes in the brain for observing genuine
[...] Read more.
Research aimed at testing whether short-term training programs can enhance intelligence is mainly concentrated on behavior. Expected positive effects are found sometimes, but the evidence is far from conclusive. It is assumed that training must evoke changes in the brain for observing genuine improvements in behavior. However, behavioral and brain data are seldom combined in the same study. Here we present one example of this latter type of research summarizing, discussing, and integrating already published results. The training program was based on the adaptive dual n-back task, and participants completed a comprehensive battery measuring fluid and crystallized ability, along with working memory and attention control, before and after training. They were also submitted to MRI scanning at baseline and post-training. Behavioral results revealed positive effects for visuospatial processing across cognitive domains. Brain imaging data were analyzed by longitudinal voxel-based morphometry, tensor-based morphometry, surface-based morphometry, and structural connectivity. The integration of these multimodal brain results provides clues about those observed in behavior. Our findings, along with previous research and current technological advances, are considered from the perspective that we now live in ideal times for (a) moving from the group to the individual and (b) developing personalized training programs. Full article
Figures

Figure 1

Open AccessArticle
Individual Differences in Developmental Change: Quantifying the Amplitude and Heterogeneity in Cognitive Change across Old Age
J. Intell. 2018, 6(1), 10; https://doi.org/10.3390/jintelligence6010010 -
Abstract
It is well known that cognitive decline in older adults is of smaller amplitude in longitudinal than in cross-sectional studies. Yet, the measure of interest rests generally with aggregated group data. A focus on individual developmental trajectories is rare, mainly because it is
[...] Read more.
It is well known that cognitive decline in older adults is of smaller amplitude in longitudinal than in cross-sectional studies. Yet, the measure of interest rests generally with aggregated group data. A focus on individual developmental trajectories is rare, mainly because it is difficult to assess intraindividual change reliably. Individual differences in developmental trajectories may differ quantitatively (e.g., larger or smaller decline) or qualitatively (e.g., decline vs improvement), as well as in the degree of heterogeneity of change across different cognitive domains or different tasks. The present paper aims at exploring, within the Geneva Variability Study, individual change across several cognitive domains in 92 older adults (aged 59–89 years at baseline) over a maximum of seven years and a half. Two novel, complementary methods were used to explore change in cognitive performance while remaining entirely at the intra-individual level. A bootstrap based confidence interval was estimated, for each participant and for each experimental condition, making it possible to define three patterns: stability, increase or decrease in performance. Within-person ANOVAs were also conducted for each individual on all the tasks. Those two methods allowed quantifying the direction, the amplitude and the heterogeneity of change for each individual. Results show that trajectories differed widely among individuals and that decline is far from being the rule. Full article
Figures

Figure 1