Cognitive Plasticity Research Articles

Exploration and spatial cognition show long-term repeatability but no heritability in the Aegean wall lizard

Recently, biologists have become increasingly interested in cognitive variation among individuals and how it relates to differences in fitness. However, very few studies so far have studied the long-term repeatability and heritability of cognitive performance in wild animals. This is nevertheless crucial information to fully understand the potential ecological and evolutionary impact of individual variation in cognitive performance. In 2019, we assessed exploration, problem solving and spatial and reversal learning in 66 Aegean wall lizards, Podarcis erhardii , then released them in seminatural enclosures consisting of either simple or complex habitat. One year later, we recaptured and retested the surviving lizards and their offspring to estimate the long-term repeatability and heritability of these behavioural and cognitive characteristics. We found that exploration and spatial learning were moderately repeatable, but reversal learning only marginally and learning flexibility and problem solving not at all. Reversal learning ability declined over time in lizards kept in simple habitat, but not in those kept in complex habitats – suggesting habitat-dependent cognitive plasticity. To our knowledge, this is the first study demonstrating (long-term) consistency in cognitive traits within a nonavian reptile. The combination of modest repeatability and low heritability does suggest that, within our study species, personality and cognitive variation among individuals and populations is mostly moulded by environmental effects. • We tested repeatability and heritability of exploration and cognition in lizards. • Only exploration and spatial learning were moderately repeatable between years. • Reversal learning was marginally repeatable. • Lizards showed habitat-dependent changes in their reversal learning abilities. • Heritability estimates were low and nonsignificant.

Prehabilitative resistance exercise reduces neuroinflammation and improves mitochondrial health in aged mice with perioperative neurocognitive disorders

BackgroundPostoperative neurocognitive dysfunction remains a significant problem in vulnerable groups such as the elderly. While experimental data regarding its possible pathogenic mechanisms accumulate, therapeutic options for this disorder are limited. In this study, we evaluated the neuroprotective effect of a period of preconditioning resistant training on aged mice undergoing abdominal surgery. Further, we examined the underlying mechanisms from the perspective of neuroinflammatory state and synaptic plasticity in the hippocampus.Methods18-month-old C57BL/6N mice were trained for 5 weeks using a ladder-climbing protocol with progressively increasing weight loading. Preoperative baseline body parameters, cognitive performance and neuroinflammatory states were assessed and compared between sedentary and trained groups of 9-month-old and 18-month-old mice. To access the neuroprotective effect of resistance training on postoperative aged mice, both sedentary and trained mice were subjected to a laparotomy under 3% sevoflurane anesthesia. Cognitive performance on postoperative day 14, hippocampal neuroinflammation, mitochondrial dysfunction and synaptic plasticity were examined and compared during groups.Results18-month-old mice have increased body weight, higher peripheral and central inflammatory status, reduction in muscle strength and cognitive performance compared with middle-aged 9-month-old mice, which were improved by resistance exercise. In the laparotomy group, prehabilitative resistant exercise improved cognitive performance and synaptic plasticity, reduced inflammatory factors and glial cells activation after surgery. Furthermore, resistance exercise activated hippocampal PGC-1α/BDNF/Akt/GSK-3β signaling and improved mitochondrial biogenesis, as well as ameliorated mitochondrial dynamics in postoperative-aged mice.ConclusionsResistance exercise reduced risk factors for perioperative neurocognitive disorders such as increased body weight, elevated inflammatory markers, and pre-existing cognitive impairment. Accordantly, preoperative resistance exercise improved surgery-induced adverse effects including cognitive impairment, synaptic deficit and neuroinflammation, possibly by facilitate mitochondrial health through the PGC1-a/BDNF pathway.

Cognitive function in female patients with chronic functional constipation

IntroductionChronic functional gastro-intestinal disorders can affect cognitive functioning of patients (1). Wong et al (2) showed attentional and executive function impairment, Aizawa et al. (3) found impairment of cognitive plasticity and activity of frontal and temporal arias of brain during performing tests in these patients.ObjectivesAssessing of cognitive functioning of the female patients with chronic functional constipation.Methods42 Rome IV adult female patients with chronic functional constipation and 26 adult normative female volunteers were tested with Brief Assessment of Cognition in Schizophrenia (BACS).ResultsBoth groups were comparable by age (patients’ group 29,5±6,1, volunteers’ group 28,5±9,6, ns) In both groups subjects demonstrated normal level of cognitive functioning but the scores of the patients were closer to the lower level than the scores of the volunteers. The difference was significant in composite scores and in several other scores (Tab.1). Table1.BACSPatients (n=42)Volunteers (n=26)p-levelVerbal Memory49,5± 10,658,8± 7,10,0002Work memory48,2±10,151,7±8,4nsMotor token51,3±10,559,8±10,40,003Verbal fluency52,1±11,556,5±9,9nsSymbol coding45,1±8,454,8±12,70,015Tower of London (planning)50,2±10,757,6±10,20,015Composite scores49,1 ±10,159,9 ±7,40,0001ConclusionsThe findings of the study once more indicate some link between gastrointestinal dysfunction and cognitive functioning. Even these slight decrease in some aspects of cognition from normal population could have negative impact on everyday functioning. The origin of this link is still under question.DisclosureNo significant relationships.

Impact of Combined Bifrontal Transcranial Direct- Current Stimulation and Conflict Processing Training on Tinnitus: a Protocol for Single-Blind Randomized Controlled Trial

Background and Aim: The deficit in cognitive functions and central executive function is one of the popular hypotheses on the underlying cause of tinnitus. These factors are not only the complications of tinnitus but are also involved in the generation of it. In this study, bifrontal transcranial Direct Current Stimulation (tDCS) and conflict processing will be used in the form of auditory Stroop training to improve cognitive performance and inhibition control for tinnitus management.
 Methods: This study will be carried out on 34 chronic tinnitus patients. The initial evaluations include the tinnitus psychoacoustic evaluations, determination of the tinnitus handicap through tinnitus handicap inventory, and examining the annoyance and loudness of tinnitus through the visual analog scale after which the participants will be investigated in two groups. The first group will receive sessions of tDCS followed by six sessions of conflict processing training. The second group will first receive tDCS in the form of sham, to be followed by six sessions of auditory Stroop. The evaluations will be repeated after each intervention.
 Discussion: Studies have shown that successive sessions of conflict processing training can enhance cognitive plasticity and inhibition function. As conflict processing training has not been addressed as rehabilitation training in the people suffering from tinnitus, these processes will be designed in four tasks as rehabilitation exercises in Farsi language and applied along with tDCS to the people with chronic tinnitus to decrease and control tinnitus by improving cognitive and inhibition control.
 Trial registration: Iranian Registry of Clinical Trials (IRCT20120215009014N366) on Sep 17th, 2020.
 Keywords: Tinnitus; conflict processing; Stroop training; inhibition

Static and Dynamic Assessment of Intelligence in ADHD Subtypes.

There is a debate about the measure of IQ in children with ADHD. Some studies report that, compared to static assessment procedures, dynamic assessment of intelligence can better measure cognitive modifiability and plasticity. The present study was designed to examine children belonging to different ADHD subtypes (inattentive, hyperactive/impulsive, and combined) in terms of both static (WISC scores) and dynamic measures (Modifiability index). Thirty-four children (12 ADHD-I, 10 ADHD-H, and 12 ADHD-C) were compared to a sample of 27 typically developing children. Results indicate that only the inattentive and the combined subtypes, compared with the normative sample, show lower IQ scores. The ADHD-I group presents generally low WISC scores and ADHD-H presents generally high WISC scores. Moreover, the ADHD-C group shows a low static score and a high dynamic score, indicating a wide breadth of Vygotskian children’s zone of proximal development. Static and dynamic measurements together can indeed be considered a comprehensive examination of intelligence levels in ADHD children and may be essential in predicting learning capacities.

Neddylation-dependent protein degradation is a nexus between synaptic insulin resistance, neuroinflammation and Alzheimer\u2019s disease

BackgroundThe metabolic syndrome is a consequence of modern lifestyle that causes synaptic insulin resistance and cognitive deficits and that in interaction with a high amyloid load is an important risk factor for Alzheimer's disease. It has been proposed that neuroinflammation might be an intervening variable, but the underlying mechanisms are currently unknown.MethodsWe utilized primary neurons to induce synaptic insulin resistance as well as a mouse model of high-risk aging that includes a high amyloid load, neuroinflammation, and diet-induced obesity to test hypotheses on underlying mechanisms.ResultsWe found that neddylation and subsequent activation of cullin-RING ligase complexes induced synaptic insulin resistance through ubiquitylation and degradation of the insulin-receptor substrate IRS1 that organizes synaptic insulin signaling. Accordingly, inhibition of neddylation preserved synaptic insulin signaling and rescued memory deficits in mice with a high amyloid load, which were fed with a 'western diet'.ConclusionsCollectively, the data suggest that neddylation and degradation of the insulin-receptor substrate is a nodal point that links high amyloid load, neuroinflammation, and synaptic insulin resistance to cognitive decline and impaired synaptic plasticity in high-risk aging.

Cognitive Phenotypic Plasticity: Environmental Enrichment Affects Learning but Not Executive Functions in a Teleost Fish, Poecilia reticulata.

Simple SummaryEnvironmental enrichment is extremely important for an individual’s neural, cognitive and behavioral development. Emerging animal models, such as teleost fish, may contribute to our understanding of enrichment-driven cognitive plasticity. We studied the cognitive consequences of living in enriched conditions in Poecilia reticulata. In particular, we compared subjects raised alone in a barren aquarium versus subjects exposed to enriched aquaria (with conspecifics, natural substrate, plants, and live prey) in three different cognitive tasks to measure learning, inhibitory control, and cognitive flexibility. Our results showed that guppies from the enriched aquaria learned a color discrimination faster compared to the subject raised in barren conditions. However, in the two remaining cognitive tasks, we found no effect from the treatment, suggesting that enrichment does not affect inhibitory control and cognitive flexibility. This study reveals that enrichment-driven plasticity affects only specific cognitive abilities.Many aspects of animal cognition are plastically adjusted in response to the environment through individual experience. A remarkable example of this cognitive phenotypic plasticity is often observed when comparing individuals raised in a barren environment to individuals raised in an enriched environment. Evidence of enrichment-driven cognitive plasticity in teleost fish continues to grow, but it remains restricted to a few cognitive traits. The purpose of this study was to investigate how environmental enrichment affects multiple cognitive traits (learning, cognitive flexibility, and inhibitory control) in the guppy, Poecilia reticulata. To reach this goal, we exposed new-born guppies to different treatments: an enrichment environment with social companions, natural substrate, vegetation, and live prey or a barren environment with none of the above. After a month of treatment, we tested the subjects in a battery of three cognitive tasks. Guppies from the enriched environment learned a color discrimination faster compared to guppies from the environment with no enrichments. We observed no difference between guppies of the two treatments in the cognitive flexibility task, requiring selection of a previously unrewarded stimulus, nor in the inhibitory control task, requiring the inhibition of the attack response toward live prey. Overall, the results indicated that environmental enrichment had an influence on guppies’ learning ability, but not on the remaining cognitive functions investigated.

Mechanisms underlying training-induced cognitive change

The prospect of enhancing cognition through behavioural training interventions, for example, the repetitive practice of cognitive tasks or metacognitive strategy instruction, has seen a surge in popularity over the past 20 years. Although overwhelming evidence demonstrates that such training interventions increase performance in the trained tasks, controversy remains over whether these benefits transfer to other tasks and abilities beyond the trained context. In this Review, we provide an overview of the effectiveness of cognitive training to induce transfer to untrained tasks, with a particular focus on the theoretical mechanisms that have been proposed to underlie training and transfer effects. We highlight that there is relatively little evidence that training enhances cognitive capacity, that is, the overall cognitive resources available to an individual. By contrast, substantial evidence supports training-induced improvements in cognitive efficiency, that is, optimized performance within existing cognitive capacity limits. We conclude that shifting research towards identifying the cognitive mechanisms underlying gains in cognitive efficiency offers a fruitful avenue for developing effective cognitive training interventions. However, to advance our understanding of human cognition and cognitive plasticity we must strive to develop and refine theories that generate testable hypotheses.

Evidence for cognitive plasticity during pregnancy via enhanced learning and memory

ABSTRACT Human and animal neuroscience studies support the view that plastic shifts occur in the brain during pregnancy that support the emergence of new maternal behaviours. The idea of adaptive plasticity in pregnancy is at odds with the notion of “baby brain”, in which pregnant women describe the onset of forgetfulness. While inconsistent evidence for memory deficits during pregnancy has been reported, few studies have investigated spatial associative memory (which is consistently enhanced in studies of pregnant rodents). Moreover, most studies assess domain-general stimuli, which might miss adaptations specific to parent-relevant stimuli. In the present study, we examined the retention of spatial associative memory for parenting-relevant and non-parenting-relevant stimuli across 4-weeks in a sample of women in their third trimester of pregnancy, and compared their performance to a sample of never pregnant women. We demonstrated that relative to never pregnant women, pregnant women exhibited enhanced long-term retention of object-scene-location associations (spatial associative memory), as well as better initial learning about parenting-relevant, relative to non-parenting-relevant, stimuli. Thus, similar to studies in rodents, cognitive improvements were seen during pregnancy in humans, and those improvements were specific to the domain of spatial associative retention, and in the recognition of stimuli relevant to parenting.

P.0698 Minocycline treatment increases cognitive performance and neural plasticity in a preclinical model of depression

P.0698 Minocycline treatment increases cognitive performance and neural plasticity in a preclinical model of depression

Improvements in Cognitive Performance With Computerized Training in Older People With and Without Cognitive Impairment: Synergistic Effects of Skills-Focused and Cognitive-Focused Strategies

ObjectivesBoth cognitively impaired (CI) and nonimpaired (NC) older people have challenges in performing everyday tasks. Previous skills training efforts in NC individuals have led to improvements in both functional skills and cognitive functioning. We evaluated the cognitive benefits of combining computerized cognitive training (CCT) with a computer-based functional skills assessment and training (CFSAT) program in a sample of CI and NC older adults. DesignRandomized parallel clinical trial with two treatment conditions: up to 24 sessions of CFSAT training alone or CFSAT plus speed focused CCT. ParticipantsNC (n = 62) and CI (n = 55) older adults, ranging in age from 60–86 years (M = 73.12), primarily female (90%), and ethnically diverse (21% Hispanic, 52% African American). Participants were divided based on Montreal Cognitive Assessment scores and cognitive complaints. SettingThree different community centers in Miami, FL. MeasurementsThe Brief Assessment of Cognition, app version, was used to measure cognitive performance across six different cognitive domains before and after training. ResultsAll six cognitive domains improved from baseline. Multivariate analyses found the effects of the combined CFSAT and CCT to be superior. The interaction of training condition and cognitive status was not statistically significant, indicating no global impact of cognitive status on improvements in cognition across training conditions. ConclusionsCFSAT training was associated with cognitive benefits, particularly in CI participants. The combined intervention led to greater improvements. Consistent with results of previous studies, there is considerable evidence of cognitive plasticity in older adults, including those with CI.

THE EFFECT OF ATTENTION PROCESS TRAINING (APT-II) ON COGNITIVE AND DAILY LIFE FUNCTIONING IN PATIENTS WITH A MILD COGNITIVE IMPAIRMENT: A RANDOMIZED CONTROLLED TRIAL

Introduction. Older adults with mild cognitive impairment (MCI) are at increased risk of developing dementia even if they do not meet the criteria for dementia. Executive control of working memory, which is implicated in divided attention, is often impaired in this population, and such impairment is a strong predictor of dementia. Slowing the development of dementia by enhancing cognitive and brain plasticity represents a current and future challenge for clinicians and researchers. Cognitive rehabilitation allows patients to compensate for cognitive deficits with the ultimate goal of reducing the impact of such deficits on everyday life. We aim to examine the effectiveness and generalization of an attention and working memory training program (Attention Process Training or APT-II) in improving cognitive and everyday functioning in patients with MCI by means of a single-blind, randomized controlled trial. Methods. Twenty-two MCI patients will be randomly assigned to either a "Cognitive Training with APT-II" group or a "Standard Care" group. Initially, patients will be administered a battery of standardized neuropsychological tests to ensure that they meet MCI criteria. The intervention will consist of a cognitive training program (APT-II) and will last 8 weeks (two sessions per week). One of the strengths of APT-II training is that it emphasizes the transfer of cognitive gains from training sessions to everyday life. To evaluate the treatment's effectiveness in improving cognitive and daily life functioning, cognitive and functional outcomes will be assessed just before, immediately after, 3 months after, and 6 months after the intervention program. A divided attention memory task performed in virtual reality will also be administered to evaluate the effects of APT-II training on the management of attentional resources in a relatively ecological situation. Perspective. If our results indicate an improvement in the cognitive and daily life performance of older adults with MCI, this non-invasive, low-cost technique may deserve increased consideration as a therapeutic intervention to delay or reverse cognitive decline an diminish the risk of developing dementia in this population. Trial registration. ClinicalTrials.gov, ID: NCT04606953, Registered on 28 October 2020. Keywords. Working memory training (WMT), Mild cognitive impairment (MCI), Dementia, Cognitive rehabilitation, Attention

Resting state EEG network modularity predicts literacy skills in L1 Chinese but not in L2 English

EEG network modularity, as a proxy for cognitive plasticity, has been proposed to be a more reliable neural marker than power and coherence in predicting learning outcomes. The present study examined the associations between resting state EEG network modularity and both L1 Chinese and L2 English literacy skills among 90 Hong Kong first to fifth graders. The modularity indices of different frequency bands were highly correlated with one another. An exploratory factor analysis, performed to extract a general modularity index, explained 77.1% of the total variance. The modularity index was positively associated with Chinese word reading, Chinese phonological awareness, Chinese morphological awareness, and Chinese reading comprehension but was not significantly correlated with English word reading or English morphological awareness. Findings suggest that resting state EEG network modularity is likely to serve as a reasonable, reliable, and cost-effective neural marker of the development of first language but not second language literacy skills.

Restoring miR-132 expression rescues adult hippocampal neurogenesis and memory deficits in Alzheimer's disease.

Neural stem cells residing in the hippocampal neurogenic niche sustain lifelong neurogenesis in the adult brain. Adult hippocampal neurogenesis (AHN) is functionally linked to mnemonic and cognitive plasticity in humans and rodents. In Alzheimer's disease (AD), the process of generating new neurons at the hippocampal neurogenic niche is impeded, yet the mechanisms involved are unknown. Here we identify miR-132, one of the most consistently downregulated microRNAs in AD, as a potent regulator of AHN, exerting cell-autonomous proneurogenic effects in adult neural stem cells and their progeny. Using distinct AD mouse models, cultured human primary and established neural stem cells, and human patient material, we demonstrate that AHN is directly affected by AD pathology. miR-132 replacement in adult mouse AD hippocampus restores AHN and relevant memory deficits. Our findings corroborate the significance of AHN in mouse models of AD and reveal the possible therapeutic potential of targeting miR-132 in neurodegeneration.

Cognitive plasticity induced by gaze-control technology: Gaze-typing improves performance in the antisaccade task

The last twenty years have seen the development of gaze-controlled computer interfaces for augmentative communication and other assistive technology applications. In many applications, the user needs to look at symbols on a virtual on-screen keyboard and maintain gaze to make a selection. Executive control is essential to learning to use gaze-control, affecting the uptake of the technology. Specifically, the user of a gaze-controlled interface must suppress looking for its own sake, the so-called “Midas touch” problem. In a pre-registered study (https://osf.io/2mak4), we tested whether gaze-typing performance depends on executive control and whether learning-dependent plasticity leads to improved executive control as measured using the antisaccade task. Forty-two university students were recruited as participants. After five 30-min training sessions, we found shorter antisaccade latencies in a gaze-control compared to a mouse-control group, and similar error-rates. Subjective workload ratings were also similar across groups, indicating the task in both groups was matched for difficulty. These findings suggest that executive control contributes to gaze-typing performance and leads to learning-induced plasticity.

Managing ECT related cognitive side effects: An individual approach

Electroconvulsive brain stimulation may represent the strongest manipulation available to study brain plasticity in humans. Brain plasticity induced by electroconvulsive brain stimulation, profoundly improves disturbed emotion and motivation in patients with depression. Electroconvulsive therapy (ECT) is a highly effective and safe treatment for psychiatric disorders like severe depression. However, there is ongoing concern about the negative impact of ECT on brain function and cognition that is, surprisingly, only seen in a part of the treated patients. After 80 years of research on ECT, virtually nothing is known about the mechanisms underlying these strong individual differences in cognitive changes induced by ECT. A first step would be to better quantify the pattern and severity of the adverse cognitive outcomes in order to better distinguish patients that suffer from adverse cognitive outcomes from those that do not or even improve. By better distinguishing of these subgroups, a second step towards understanding can be taken: to identify the factors that predict adverse cognitive outcomes. Our research aims to advance understanding of the mechanisms of cognitive plasticity and reveal the pre-treatment profiles that render a patient cognitive vulnerable or resilient.DisclosureNo significant relationships.

Cross-Modal Transfer Following Auditory Task-Switching Training in Old Adults.

Maintaining and coordinating multiple task-sets is difficult and leads to costs, however task-switching training can reduce these deficits. A recent study in young adults demonstrated that this training effect occurs at an amodal processing level. Old age is associated with reduced cognitive plasticity and further increases the performance costs when mixing multiple tasks. Thus, cognitive aging might be a limiting factor for inducing cross-modal training effects in a task-switching environment. We trained participants, aged 62–83 years, with an auditory task-switching paradigm over four sessions (2880 total trials), to investigate whether training-related reductions in task-switching costs would also manifest in an untrained visual modality version of the task. Two control groups trained with single tasks (active control) or not trained (passive control) allowed us to identify improvements specific to task-switching training. To make statistical evaluations of any age differences in training and cross-modal transfer, the data from the Kattner cohort were incorporated into the present analysis. Despite the tendency for older adults to respond more cautiously, task-switching training specifically led to a mixing cost reduction in both trained and untrained modalities, the magnitude of which was statistically similar regardless of age. In line with a growing body of research, we failed to observe any far transfer effects in measures of inhibition, working memory or fluid intelligence. Overall, we conclude that any apparent cognitive limitations associated with aging do not prevent cognitive control processes which support set-shifting from improving at an amodal level.

Post-training stimulation of the right dorsolateral prefrontal cortex impairs working memory training performance.

Research investigating transcranial direct current stimulation (tDCS) to enhance cognitive training augments both our understanding of its long-term effects on cognitive plasticity as well as potential applications to strengthen cognitive interventions. Previous work has demonstrated enhancement of working memory training while applying concurrent tDCS to the dorsolateral prefrontal cortex (DLPFC). However, the optimal stimulation parameters are still unknown. For example, the timing of tDCS delivery has been shown to be an influential variable that can interact with task learning. In the present study, we used tDCS to target the right DLPFC while participants trained on a visuospatial working memory task. We sought to compare the relative efficacy of online stimulation delivered during training to offline stimulation delivered either immediately before or afterwards. We were unable to replicate previously demonstrated benefits of online stimulation; however, we did find evidence that offline stimulation delivered after training can actually be detrimental to training performance relative to sham. We interpret our results in light of evidence suggesting a role of the right DLPFC in promoting memory interference, and conclude that while tDCS may be a promising tool to influence the results of cognitive training, more research and an abundance of caution are needed before fully endorsing its use for cognitive enhancement. This work suggests that effects can vary substantially in magnitude and direction between studies, and may be heavily dependent on a variety of intervention protocol parameters such as the timing and location of stimulation delivery, about which our understanding is still nascent.

Predicting Working Memory Training Responsiveness in Parkinson’s Disease: Both “System Hardware” and Room for Improvement Are Needed

Background. Patients with Parkinson’s disease (PD) are highly vulnerable to develop cognitive dysfunctions, and the mitigating potential of early cognitive training (CT) is increasingly recognized. Predictors of CT responsiveness, which could help to tailor interventions individually, have rarely been studied in PD. This study aimed to examine individual characteristics of patients with PD associated with responsiveness to targeted working memory training (WMT). Methods. Data of 75 patients with PD (age: 63.99 ± 9.74 years, 93% Hoehn & Yahr stage 2) without cognitive dysfunctions from a randomized controlled trial were analyzed using structural equation modeling. Latent change score models with and without covariates were estimated and compared between the WMT group (n = 37), who participated in a 5-week adaptive WMT, and a waiting list control group (n = 38). Results. Latent change score models yielded adequate model fit (χ2-test p > .05, SRMR ≤ .08, CFI ≥ .95). For the near-transfer working memory composite, lower baseline performance, younger age, higher education, and higher fluid intelligence were found to significantly predict higher latent change scores in the WMT group, but not in the control group. For the far-transfer executive function composite, higher self-efficacy expectancy tended to significantly predict larger latent change scores. Conclusions. The identified associations between individual characteristics and WMT responsiveness indicate that there has to be room for improvement (e.g., lower baseline performance) and also sufficient “hardware” (e.g., younger age, higher intelligence) to benefit in training-related cognitive plasticity. Our findings are discussed within the compensation versus magnification account. They need to be replicated by methodological high-quality research applying advanced statistical methods with larger samples.

Selective Inhibition of Mirror Invariance for Letters Consolidated by Sleep Doubles Reading Fluency

Mirror invariance is a visual mechanism that enables a prompt recognition of mirror images. This visual capacity emerges early in human development, is useful to recognize objects, faces, and places from both left and right perspectives, and is also present in primates, pigeons, and cephalopods. Notwithstanding, the same visual mechanism has been suspected to be the source of a specific difficulty for a relatively recent human invention-reading-by creating confusion between mirror letters (e.g., b-d in the Latin alphabet). Using an ecologically valid school-based design, we show here that mirror invariance represents indeed a major leash for reading fluency acquisition in first graders. Our causal approach, which specifically targeted mirror invariance inhibition for letters, in a synergic combination with post-training sleep to increase learning consolidation, revealed unprecedented improvement in reading fluency, which became two-times faster. This gain was obtained with as little as 7.5h of multisensory-motor training to distinguish mirror letters, such as "b" versus "d." The magnitude, automaticity, and duration of this mirror discrimination learning were greatly enhanced by sleep, which keeps the gains perfectly intact even after 4months. The results were consistently replicated in three randomized controlled trials. They not only reveal an extreme case of cognitive plasticity in humans (i.e., the inhibition in just 3weeks of a ∼25-million-year-old visual mechanism), that allows adaptation to a cultural activity (reading), but at the same time also show a simple and cost-effective way to unleash the reading fluency potential of millions of children worldwide.