Latent profile analysis of working memory capacity and thinking styles in adults and adolescents

This study of adults (n = 269) and adolescents (n = 308) applied latent profile analysis to preference for rational and/or experiential cognition, coupled with working memory capacity (WMC). A 4-profile solution comprising rationally dominant, experientially dominant, dual preference, and disengaged groups was retained for both adult and adolescent samples. Our solution indicated that high WMC was associated with both preference and ability to engage in rational processing. Profile membership significantly discriminated both adults and adolescents on several reasoning tasks and measures of cognitive biases. Overall our results indicate that cognitive processing styles and WMC can be combined to create a typology that distinguishes between four types of thinkers who significantly differ in their performance on reasoning tasks.     

Right-hemispheric cortical contributions to language ability in healthy adults

In this study we investigated the correlation between individual linguistic ability based on performance levels and their engagement of typical and atypical language areas in the brain. Eighteen healthy subjects between 21 and 64 years participated in language ability tests, and subsequent functional MRI scans measuring brain activity in response to a sentence completion and a word fluency task. Performance in both reading and high-level language tests correlated positively with increased right-hemispheric activation in the inferior frontal gyrus (specifically Brodmann area 47), the dorsolateral prefrontal cortex (DLPFC), and the medial temporal gyrus (Brodmann area 21). In contrast, we found a negative correlation between performance and left-hemispheric DLPFC activation.Our findings indicate that the right lateral frontal and right temporal regions positively modulate aspects of language ability.     

Training the brain: fact and fad in cognitive and behavioral remediation

Putatively safe and effective for improving cognitive performance in both health and disease, products purported to train the brain appeal to consumers and healthcare practitioners. In an increasingly health-centered society, these applications constitute a burgeoning commercial market. Sparse evidence coupled with lack of scientific rigor, however, leaves claims concerning the impact and duration of such brain training largely unsubstantiated. On the other hand, at least some scientific findings seem to support the effectiveness and sustainability of training for higher brain functions such as attention and working memory. In the present paper we provide a tectonic integration and synthesis of cognitive training approaches. Specifically, we sketch the relative merits and shortcomings of these programs, which often appeal to parents who must choose between side-effect-laden medication and other less conventional options. Here we examine how neuroplasticity allows the healthy as well the impaired to benefit from cognitive training programs. We evaluate the evidence and consider whether brain training can be a stand-alone treatment or an adjunct to pharmacotherapy, outline promising future prospects, and highlight what training outcomes are plausible in line with available data. Future research would determine whether the field of brain training realizes its potential to revolutionize education and rehabilitation or withers away engulfed in controversy.     

Brain activation during spatial updating and attentive tracking of moving targets

Keeping aware of the locations of objects while one is moving requires the updating of spatial representations. As long as the objects are visible, attentional tracking is sufficient, but knowing where objects out of view went in relation to one's own body involves an updating of spatial working memory. Here, multiple object tracking was employed to study spatial updating and its neural correlates. In a dynamic 3D-scene, targets moved among visually indistinguishable distractors. The targets and distractors either stayed visible during continuous viewpoint changes or they turned invisible. The parametric variation of tracking load revealed load-dependent activations of the intraparietal sulcus, the superior parietal lobule, and the lateral occipital cortex in response to the attentive tracking task. Viewpoint changes with invisible objects that demanded retention and updating produced load-dependent activation only in the precuneus in line with its presumed involvement in updating spatial working memory.     

Insights into spared memory capacity in amnestic MCI and Alzheimer's Disease via minimal interference

Impairment on standard tests of delayed recall is often already maximal in the aMCI stage of Alzheimer's Disease. Neuropathological work shows that the neural substrates of memory function continue to deteriorate throughout the progression of the disease, hinting that further changes in memory performance could be tracked by a more sensitive test of delayed recall. Recent work shows that retention in aMCI patients can be raised well above floor when the delay period is devoid of further material - 'Minimal Interference'. This memory enhancement is thought to be the result of improved memory consolidation. Here we used the minimal interference/interference paradigm (word list retention following 10 min of quiet resting vs. picture naming) in a group of 17 AD patients, 25 aMCI patients and 25 controls. We found (1) that retention can be improved significantly by minimal interference in patients with aMCI and patients with mild to moderate AD; (2) that the minimal interference paradigm is sensitive to decline in memory function with disease severity, even when performance on standard tests has reached floor; and (3) that this paradigm can differentiate well (80% sensitivity and 100% specificity) between aMCI patients who progress and do not progress to AD within 2 years. Our findings support the notion that the early memory dysfunction in AD is associated with an increased susceptibility to memory interference and are suggestive of a gradual decline in consolidation capacity with disease progression.     

Perspective-taking and depth of theory-of-mind reasoning in sequential-move games

Theory-of-mind (ToM) involves modeling an individual's mental states to plan one's action and to anticipate others' actions through recursive reasoning that may be myopic (with limited recursion) or predictive (with full recursion). ToM recursion was examined using a series of two-player, sequential-move matrix games with a maximum of three steps. Participants were assigned the role of Player I, controlling the initial and the last step, or of Player II, controlling the second step. Appropriate for the assigned role, participants either anticipated or planned Player II's strategy at the second step, and then determined Player I's optimal strategy at the first step. Participants more readily used predictive reasoning as Player II (i.e., planning one's own move) than as Player I (i.e., anticipating an opponent's move), although they did not differ when translating reasoning outcome about the second step to optimal action in the first step. Perspective-taking influenced likelihood of predictive reasoning, but it did not affect the rate at which participants acquired it during the experimental block. We conclude that the depth of ToM recursion (related to perspective-taking mechanisms) and rational application of belief-desire to action (instrumental rationality) constitute separate cognitive processes in ToM reasoning.     

Online recognition of music is influenced by relative and absolute pitch information

Three experiments explored online recognition in a nonspeech domain, using a novel experimental paradigm. Adults learned to associate abstract shapes with particular melodies, and at test they identified a played melody's associated shape. To implicitly measure recognition, visual fixations to the associated shape versus a distractor shape were measured as the melody played. Degree of similarity between associated melodies was varied to assess what types of pitch information adults use in recognition. Fixation and error data suggest that adults naturally recognize music, like language, incrementally, computing matches to representations before melody offset, despite the fact that music, unlike language, provides no pressure to execute recognition rapidly. Further, adults use both absolute and relative pitch information in recognition. The implicit nature of the dependent measure should permit use with a range of populations to evaluate postulated developmental and evolutionary changes in pitch encoding.     

The development of automatic and controlled inhibitory retrieval processes in true and false recall

In three experiments, we investigated the role of automatic and controlled inhibitory retrieval processes in true and false memory development in children and adults. Experiment 1 incorporated a directed forgetting task to examine controlled retrieval inhibition. Experiments 2 and 3 used a part-set cue and retrieval practice task to examine automatic retrieval inhibition. In the first experiment, the forget cue had no effect on false recall for adults but reduced false recall for children. In Experiments 2 and 3, both tasks caused retrieval impairments for true and false recall, and this occurred for all age groups. Implicit inhibition, which occurs outside of our conscious control, appears early in childhood. However, because young children do not process false memories as automatically as adults, explicit inhibition can reduce false memory output.     

Assessment of working memory components at 6years of age as predictors of reading achievements a year later

The ability of working memory skills (measured by tasks assessing all four working memory components), IQ, language, phonological awareness, literacy, rapid naming, and speed of processing at 6 years of age, before reading was taught, to predict reading abilities (decoding, reading comprehension, and reading time) a year later was examined in 97 children. Among all working memory components, phonological complex memory contributed most to predicting all three reading abilities. A capacity measure of phonological complex memory, based on passing a minimum threshold in those tasks, contributed to the explained variance of decoding and reading comprehension. Findings suggest that a minimal ability of phonological complex memory is necessary for children to attain a normal reading level. Adding assessment of phonological complex memory, before formal teaching of reading begins, to more common measures might better estimate children’s likelihood of future academic success.     

Understanding memory impairment with memory models and hierarchical Bayesian analysis

The study of human episodic memory is a topic that interests cognitive and mathematical psychologists as well as clinicians interested in the diagnosis and assessment of Alzheimer’s disease and related disorders (ADRD). In this paper, we use simple cognitive models for the recognition and recall tasks typically applied in clinical assessments of ADRD to study memory performance in ADRD patients. Our models make use of hierarchical Bayesian methods as a way to model individual differences in patient performance and to facilitate the modeling of performance changes that occur during multiple recall tasks. We show how the models are able to account for different aspects of patient performance, and also discuss some of the predictive capabilities of the model. We conclude with a discussion on the scope to improve on our results by discussing the link between memory theory in psychology and clinical practice.