Cognitive Neuroscience: Rewired or Crosswired Brains?

A new study of congenitally blind participants has provided important insights into the neuronal mechanisms of brain reorganization after injury, with implications for our knowledge of other cross-modal phenomena, such as synaesthesia, and for the generation of qualia.     

Do Older Professional Musicians Have Cognitive Advantages?

The current study investigates whether long-term music training and practice are associated with enhancement of general cognitive abilities in late middle-aged to older adults. Professional musicians and non-musicians who were matched on age, education, vocabulary, and general health were compared on a near-transfer task involving auditory processing and on far-transfer tasks that measured spatial span and aspects of cognitive control. Musicians outperformed non-musicians on the near-transfer task, on most but not all of the far-transfer tasks, and on a composite measure of cognitive control. The results suggest that sustained music training or involvement is associated with improved aspects of cognitive functioning in older adults.     

Cognitive ecology: a field of substance?

In 1993, Les Real invented the label 'cognitive ecology'. This label was intended for work that brought cognitive science and behavioural ecology together. Real's article stressed the importance of such an approach to the understanding of behaviour. At the end of a decade in which more interdisciplinary work on behaviour has been seen than for many years, it is time to assess whether cognitive ecology is a label describing an active field.     

Prevalence of Cognitive Impairment in Recently Diagnosed Type 2 Diabetes Patients: Are Chronic Inflammatory Diseases Responsible for Cognitive Decline?

ObjectiveTo estimate the prevalence of cognitive impairment (CI) among patients recently diagnosed with type 2 diabetes (RDD) and to identify any relationships between CI and RDD comorbidities. Methods: One thousand seven hundred twelve patients with RDD participated in a cross-sectional study. The patients’ sociodemographic and clinical data were registered.ResultsThe sample population had an average age of 51 ± 11 years, and 63.26% of the patients were female. CI was diagnosed in 38 patients (2.2%) and was more common among both females (2.8% vs. 1.3%, p = 0.063) and the elderly (0% at an age ≤ 30 years vs. 10.4% at an age > 70 years, p = 0.0001). Rheumatoid arthritis (present in 15.8% vs. absent in 2.1%) and asthma (13% vs. 2.1%) correlated significantly with CI based on the results of our logistic regression analysis.ConclusionAge, female gender, rheumatoid arthritis and asthma are risk factors for CI in the setting of RDD.     

Cognitive Aging: Recapturing the Excitation of Youth?

The electrical excitability of cortical neurons changes significantly during normal ageing. A recent study found that targeted deletion of a gene encoding a potassium channel-modifier subunit can restore to aged mice, not only normal neuronal firing, but also normal learning and synaptic plasticity.     

Gastrodin Attenuates Cognitive Deficits Induced by 3,3′-Iminodipropionitrile

3,3′-Iminodipropionitrile (IDPN), one of the nitrile derivatives, can induce persistent neurotoxicity, and therefore cause dyskinesia and cognitive impairments. Gastrodin, a main bioactive ingredient of Gastrodia elata Blume, is shown to greatly improve cognitive function. The aim of this study was to further determine whether administration of gastrodin can ameliorate IDPN-induced cognitive deficits in the Morris water maze (MWM) and novel object recognition (NOR) task, and to explore the underlying mechanisms. Results showed that exposure to IDPN (100 mg/kg/day, for 8 days) significantly impaired spatial and object recognition memory and that repeated treatment with gastrodin (150 mg/kg/day, for 6 weeks) could effectively alleviate the IDPN-induced cognitive impairments as indicated by increased spatial memory and discrimination ratio in the MWM and NOR tests. Gastrodin treatment also reverted IDPN-induced decreases of γ-aminobutyric acid (GABA) levels and increases of a2 GABA_A receptor protein expression in the prefrontal cortex and hippocampus of IDPN-treated rats. These results suggest that gastrodin treatment may provide a novel pharmacological strategy for IDPN-induced cognitive deficits, which was mediated, at least in part, by normalizing the GABAergic system.

     

Cognitive predictors of balance in Parkinson’s disease

Postural instability is one of the most incapacitating symptoms of Parkinson’s disease (PD) and appears to be related to cognitive deficits. This study aims to determine the cognitive factors that can predict deficits in static and dynamic balance in individuals with PD. A sociodemographic questionnaire characterized 52 individuals with PD for this work. The Trail Making Test, Rule Shift Cards Test, and Digit Span Test assessed the executive functions. The static balance was assessed using a plantar pressure platform, and dynamic balance was based on the Timed Up and Go Test. The results were statistically analysed using SPSS Statistics software through linear regression analysis. The results show that a statistically significant model based on cognitive outcomes was able to explain the variance of motor variables. Also, the explanatory value of the model tended to increase with the addition of individual and clinical variables, although the resulting model was not statistically significant The model explained 25–29% of the variability of the Timed Up and Go Test, while for the anteroposterior displacement it was 23–34%, and for the mediolateral displacement it was 24–39%. From the findings, we conclude that the cognitive performance, especially the executive functions, is a predictor of balance deficit in individuals with PD.     

Cognitive Ability: Does Working Memory Training Enhance Intelligence?

Recent experiments in both humans and mice suggest that working memory training improves general cognitive ability. While the prospect of enhancing human and animal intelligence is enticing, several questions remain.     

Il1-β Involvement in Cognitive Impairment after Sepsis

Sepsis is defined as the host's reaction to infection and characterised by a systemic inflammatory response with important clinical implications. Central nervous system dysfunction secondary to sepsis is associated with local generation of pro- and anti-inflammatory cytokines, impaired cerebral microcirculation, an imbalance of neurotransmitters, apoptosis and cognitive impairment. It's known that the IL-1β is one of the first cytokines to be altered. Thus, the objective of this study was to evaluate the role of IL-1β in cognitive parameters in brain tissue through the use of an IL-1β (IL-1ra) receptor antagonist up to 10 days and to assess blood–brain barrier permeability, cytokine levels, oxidative parameters and energetic metabolism up to 24 h, after sepsis induction. To this aim, we used sham-operated Wistar rats or submitted to the cecal ligation and perforation (CLP) procedure. Immediately after, the animals received one dose of 10 μg of IL-1ra. After 24 h, the rats were killed and were evaluated for biochemical parameters in the pre-frontal cortex, hippocampus and striatum. After 10 days, the animals were submitted to the habituation to the open field and step-down inhibitory avoidance task. We observed that the use of IL-1ra reverted the increase of blood–brain barrier permeability in the pre-frontal cortex, hippocampus and striatum; the increase of IL-1β, IL1-6 and TNF-α levels in the pre-frontal cortex and striatum; the decrease of complex I activity in the pre-frontal, hippocampus and striatum; the increase of oxidative parameters in pre-frontal cortex, hippocampus and striatum; and cognitive impairment. In conclusion, the results observed in this study reinforce the role of acute brain inflammatory response, in particular, the IL1β response, in the cognitive impairment associated with sepsis.     

Diabetes and Cognitive Decline: Are Steroids the Missing Link?

Although elevated cortisol levels may be found in diabetes, cortisol's role in diabetes-associated cognitive impairment is unclear. A recent study (Stranahan et al., 2008) shows that reducing glucocorticoid levels in rodent diabetes models prevents cognitive deficits and enhances neurogenesis and synaptic plasticity. The clinical relevance of these intriguing findings remains undetermined.     

Behavior Matters—Cognitive Predictors of Survival in Amyotrophic Lateral Sclerosis

Background

It is difficult to longitudinally characterize cognitive impairment in amyotrophic lateral sclerosis (ALS) due to motor deficits, and existing instruments aren’t comparable with assessments in other dementias.

Methods

The ALS Brief Cognitive Assessment (ALS-BCA) was validated in 70 subjects (37 with ALS) who also underwent detailed neuropsychological analysis. Cognitive predictors for poor survival were then analyzed in a longitudinal cohort of 171 ALS patients.

Results

The ALS-BCA was highly sensitive (90%) and specific (85%) for ALS-dementia (ALS-D). ALS-D patients had shorter overall survival, primarily due to the poor survival among ALS-D patients with disinhibited or apathetic behaviors after adjusting for demographic variables, ALS site of onset, medications, and supportive measures. ALS-D without behavioral changes was not a predictor of poor survival.

Conclusion

ALS-D can present with or without prominent behavioral changes. Cognitive screening in ALS patients should focus on behavioral changes for prognosis, while non-behavioral cognitive impairments may impact quality of life without impacting survival.     

Does Cognitive Function Increase over Time in the Healthy Elderly?

Background

In dementia screening, most studies have focused on early cognitive impairment by comparing patients suffering from mild dementia or mild cognitive impairment with normal subjects. Few studies have focused on modifications over time of the cognitive function in the healthy elderly. The objective of the present study was to analyze the cognitive function changes of two different samples, born > 15 years apart.

Method

A first sample of 204 cognitively normal participants was recruited in the memory clinic of Broca hospital between 1991 and 1997. A second sample of 177 cognitively normal participants was recruited in 2008–2009 in the same institution. Both samples were from the same districts of Paris and were assessed with the same neuropsychological test battery. Mean cognitive test scores were compared between 1991 and 2008 samples, between < 80 years old and ≥ 80 years old in 1991 and 2008 samples, and finally between subjects < 80 year old of 1991 sample and subjects ≥ 80 years old of the 2008 sample. Means were compared with T-tests stratified on gender, age-groups and educational level.

Results

Cognitive scores were significantly higher in the 2008 sample. Participants < 80 years old outperformed those ≥ 80 in both samples. However, participants < 80 years old in 1991 sample and subjects ≥ 80 in the 2008 sample, born on average in 1923, performed mostly identically.

Conclusion

This study showed a significant increase of cognitive scores over time. Further, contemporary octogenarians in the later sample performed like septuagenarians in the former sample. These findings might be consistent with the increase in life expectancy and life span in good health. The study highlights the necessity to take into account factors which may contaminate and artificially inflate the age-related differences in favor of younger to the older adults.     

Cognitive mechanisms of risky choice: is there an evaluation cost?

We contrast two classes of choice processes, those assuming time-consuming comparisons and those where stimuli for each option act independently, competing for expression by cross censorship. The Sequential Choice Model (SCM) belongs in the latter category, and has received empirical support in several procedures involving deterministic alternatives. Here we test this model in risky choices. In two treatments, each with five conditions, European starlings (Sturnus vulgaris) faced choices between options with unpredictable outcomes and risk-free alternatives. In the delay treatment the five conditions involved choices between a variable option offering two equiprobable delays to reward and a fixed option with delay differing between conditions. The amount treatment was structurally similar, but amount of reward rather than delay was manipulated. As assumed (and required) by the SCM, latency to respond in no-choice trials reflected each option's richness with respect to the background alternatives, and, crucially, preferences in simultaneous choices were predictable from latencies to each option in forced trials. However, we did not detect reliable differences in response times between forced and choice trials, neither the lengthening expected from evaluation models nor the shortening expected from the SCM.     

Directed Network Motifs in Alzheimer’s Disease and Mild Cognitive Impairment

Directed network motifs are the building blocks of complex networks, such as human brain networks, and capture deep connectivity information that is not contained in standard network measures. In this paper we present the first application of directed network motifs in vivo to human brain networks, utilizing recently developed directed progression networks which are built upon rates of cortical thickness changes between brain regions. This is in contrast to previous studies which have relied on simulations and in vitro analysis of non-human brains. We show that frequencies of specific directed network motifs can be used to distinguish between patients with Alzheimer’s disease (AD) and normal control (NC) subjects. Especially interesting from a clinical standpoint, these motif frequencies can also distinguish between subjects with mild cognitive impairment who remained stable over three years (MCI) and those who converted to AD (CONV). Furthermore, we find that the entropy of the distribution of directed network motifs increased from MCI to CONV to AD, implying that the distribution of pathology is more structured in MCI but becomes less so as it progresses to CONV and further to AD. Thus, directed network motifs frequencies and distributional properties provide new insights into the progression of Alzheimer’s disease as well as new imaging markers for distinguishing between normal controls, stable mild cognitive impairment, MCI converters and Alzheimer’s disease.     

Cognitive brain–Computer interface and probable aspects of its practical application

A new type of brain-computer interface was elaborated. It considers a variety of brain activity parameters to determine the type of mental operation being performed at the moment. The corresponding algorithm previously developed in the lab was modified for real-time application. The possibility of interface application for cognitive skills training was investigated. In the proposed paradigm, as soon as the EEG spectral pattern was adequate for the current task, some clue to the solution was presented. As we supposed, such positive biofeedback should facilitate memorization of the current brain state. After just one learning session, the differences in EEG spectra, corresponding to two types of tasks, were concentrated in more narrow frequency ranges. It indicates a decrease in mental effort. Moreover, the majority of subjects succeeded in solving the tasks faster, which is evidence of increased efficiency. The developed interface could be used for the new type of training, based on objective features of brain activity.