Neonatal spectral EEG is prognostic of cognitive abilities at school age in premature infants without overt brain damage.

Prematurity is a prototype of biological risk that could affect the late neurocognitive outcome; however, the condition itself remains a non-specific marker. This longitudinal 6-year study aimed to evaluate the prognostic role of neonatal spectral EEG in premature infants without neurological complications. The study cohort was 26 children born 23-34 gestational ages; all neonates underwent multichannel EEG recordings at 35 weeks post-conception. EEG data were transformed into the frequency domain and divided into delta (0.5-4 Hz), theta (5-7 Hz), alpha (8-13 Hz), and beta (14-20 Hz) frequency bands. At 6 years, a neuropsychological and behavioral evaluation was performed. Correlations between spectral bands and neuropsychological assessments were performed with a conservative and robust Bayesian correlation model using weakly informative priors. The correlation of neuropsychological tasks to spectral frequency bands highlighted a significant association with visual and auditory attention tests. The performance on the same tests appears to be mainly impaired.Conclusions: We found that spectral EEG frequencies are independent predictors of performance in attention tasks. We hypothesized that spectral EEG might reflect early circuitries' imbalance in the reticular ascending system and cumulative effect on ongoing development, pointing to the importance of early prognostic instruments. What is Known: • Prematurity is a non-specific marker of late neurocognitive risk. • Precise prognostic instruments are lacking, mostly in patients with low-grade conditions. What is New: • Longitudinal long-term studies are scarce but crucial for the inferential attributive process. • Spectral EEG frequencies are independent predictors of performance in attention tasks.

Intentional binding as a marker of agency across the lifespan.

The feeling of control over actions and their external effects is known as Sense of Agency (SoAg). People usually have a distinctive SoAg for events caused by their own actions. However, if the agent is a child or an older person, this feeling of being responsible for the consequences of an action may differ from what an adult would feel. The idea would be that children and elderly may have a reduced SoAg since their frontal lobes are developing or have started to loose their efficiency. The aim of this study was to elucidate whether the SoAg changes across lifespan, using the Intentional Binding (i.e., the temporal attraction between a voluntary action and its sensory consequence) as implicit measure. Data show that children and elderly are characterized by a reduced SoAg as compared to adults. These findings provide a fundamental step in the characterization of SoAg dynamics throughout individuals' lifetime.

Spatiotemporal neurodynamics underlying internally and externally driven temporal prediction: a high spatial resolution ERP study.

Temporal prediction (TP) is a flexible and dynamic cognitive ability. Depending on the internal or external nature of information exploited to generate TP, distinct cognitive and brain mechanisms are engaged with the same final goal of reducing uncertainty about the future. In this study, we investigated the specific brain mechanisms involved in internally and externally driven TP. To this end, we employed an experimental paradigm purposely designed to elicit and compare externally and internally driven TP and a combined approach based on the application of a distributed source reconstruction modeling on a high spatial resolution electrophysiological data array. Specific spatiotemporal ERP signatures were identified, with significant modulation of contingent negative variation and frontal late sustained positivity in external and internal TP contexts, respectively. These different electrophysiological patterns were supported by the engagement of distinct neural networks, including a left sensorimotor and a prefrontal circuit for externally and internally driven TP, respectively.

Neural underpinnings of the 'agent brain': new evidence from transcranial direct current stimulation.

Intentional binding (IB) refers to the temporal compression between a voluntary action and its sensory effect, and it is considered an implicit measure of sense of agency (SoA), that is, the capacity to control one's own actions. IB has been thoroughly studied from a behavioural point of view but only few studies have investigated its neural underpinnings, always using the same two paradigms. Although providing evidence that the supplementary motor complex is involved, findings are still too scarce to draw definitive conclusions. The aim of the present study was to establish a causal relationship between the pre-supplementary motor area (pre-SMA), known for its key role in action planning and initiation, and IB by means of transcranial direct current stimulation (tDCS). Participants underwent anodal, cathodal and sham control stimulations during three separate sessions (Experiment I). Subsequently, they underwent the same stimulation protocol (Experiment II) using as control a region potentially involved in the processing of the sensory effects of voluntary action (i.e., the right primary auditory cortex for the auditory effects of action). A significant reduction in IB was found only after stimulation of the pre-SMA, which supports the causal contribution of this prefrontal area in the perceived linkage between action and its effects. As SoA could be disrupted in many psychiatric and neurological diseases, these results have direct clinical relevance as tDCS could be successfully used in this domain in virtue of the promising advantages it offers for rehabilitation.

Female gender doubles executive dysfunction risk in ALS: a case-control study in 165 patients.

BACKGROUND: Cognitive impairment, mainly characterised by executive dysfunction, occurs in about half of cases in amyotrophic lateral sclerosis (ALS). There is evidence that gender influences some clinical features of the disease, but its influence on the cognitive spectrum is unknown. Our objective was to investigate the impact of gender on cognitive profiles of patients with ALS. METHODS: A retrospective study based on an exhaustive neuropsychological battery was performed in a group of 165 (70 females, 95 males) sporadic, non-demented patients with ALS compared with 134 healthy control participants. This assessment primarily focused on executive, memory and language functions. RESULTS: 47 (29%) patients revealed impairment in executive function and 30 (18%) patients revealed cognitive non-executive impairment. Independent from mood tone and clinical variables, a significantly greater executive impairment was determined in female patients than in male patients and control participants. The relative risk for ALS females having impairment in executive function compared with male patients was 2.6 (95% CI 1.6 to 4.4; p=0.0003). ALS females scored lower in Phonemic Fluency, Trial Making, and Wisconsin Card Sorting test. CONCLUSIONS: Results highlight a significant vulnerability of ALS female patients to develop cognitive dysfunctions peculiar to the disease, independently of bulbar onset. The explicative hypotheses of the data are focused on two interpretative lines not mutually exclusive: the role of gonadal hormones and gender-related brain asymmetry pre-existing to the disease. These findings, never reported before in the literature, can have important implications for models of ALS pathogenesis and for future clinical trial designs.

Time-on-task in children with ADHD: an ex-Gaussian analysis.

Although it is widely known that high intra-individual variability (IIV) is a key characteristic of attention deficit/hyperactivity disorder (ADHD), a detailed exploration of the IIV pattern during the time course of a cognitive task has never been carried out. In this study, 30 children with ADHD and 30 controls, were administered the Conners' Continuous Performance Task (CPT-II). The across-block individual performance of the groups was analyzed using an ex-Gaussian approach, which enabled a clearer understanding of how individual response times (RTs) fluctuate during a task in comparison with conventional measures of central tendency. While the conventional measures showed a significant group effect on mean RTs but similar RT trends across blocks between the two groups, the ex-Gaussian results revealed no actual differences between the two groups in the normally distributed component of mean RTs (mu). In contrast to the control group, the children with ADHD showed a steep increase in the exponentially distributed component of RTs (tau) across blocks, thereby indicating that extremely long RTs progressively increased soon after the beginning of the task. Taken together, the results demonstrated that sustained attention deficit in ADHD can be detected by analyzing the IIV in the first few task blocks.

Young adults and multisensory time perception: Visual and auditory pathways in comparison.

The brain continuously encodes information about time, but how sensorial channels interact to achieve a stable representation of such ubiquitous information still needs to be determined. According to recent research, children show a potential interference in multisensory conditions, leading to a trade-off between two senses (sight and audition) when considering time-perception tasks. This study aimed to examine how healthy young adults behave when performing a time-perception task. In Experiment 1, we tested the effects of temporary sensory deprivation on both visual and auditory senses in a group of young adults. In Experiment 2, we compared the temporal performances of young adults in the auditory modality with those of two samples of children (sighted and sighted but blindfolded) selected from a previous study. Statistically significant results emerged when comparing the two pathways: young adults overestimated and showed a higher sensitivity to time in the auditory modality compared to the visual modality. Restricting visual and auditory input did not affect their time sensitivity. Moreover, children were more accurate at estimating time than young adults after a transient visual deprivation. This implies that as we mature, sensory deprivation does not constitute a benefit to time perception, and supports the hypothesis of a calibration process between senses with age. However, more research is needed to determine how this calibration process affects the developmental trajectories of time perception.

[Mini Mental State Examination and Brief neuropsychological Examination as neuropsychological screening tools]. / L'uso del Mini Mental State Examination e dell'Esame Neuropsicologico Breve come strumenti di screening neuropsicologico.

INTRODUCTION: An adequate neuropsychological evaluation is essential today to obtain a correct diagnosis in most neurological and geriatric areas. For these purposes, a number of screening and evaluation tools are in use to aid the neuropsychologist for diagnosis of cognitive disorder and for assessing the type of the disease. OBJECTIVE: The present research compares two neuropsychological tools, commonly used in the daily practice: the "Mini Mental State Examination" and the "Brief Neuropsychological Examination". METHOD: This study explores the neuropsychological profile of 56 post-stroke patients in rehabilitation phase. Patients were divided in three groups, in order to the stroke brain area: left, right and multinfarctual. RESULTS: No significant difference in the three pathological groups were observed, in the mean MMSE-score. On the opposite, ENB demonstrated higher sensitivity and specificity in discrimination between pathological groups, but only on the descriptive level: for example, right-stroke patients performed worse in visuo-spatial tests while left-stroke patients had lower performance in verbal memory tests. CONCLUSIONS: Our results showed an inadequacy of neuropsychological screening evaluation in post-stroke patients: both Mini Mental State Examination and the Brief Neuropsychological Examination appear to be inadequate to underline specific cognitive deficits in patients with different brain lesions; therefore it is important to consider the tools adequacy and the time-after-stroke when doing neuropsychological evaluation.

Long-Term Outcomes after Neonatal Hypoxic-Ischemic Encephalopathy in the Era of Therapeutic Hypothermia: A Longitudinal, Prospective, Multicenter Case-Control Study in Children without Overt Brain Damage.

BACKGROUND: Data on long-term outcomes in the era before therapeutic hypothermia (TH) showed a higher incidence of cognitive problems. Since the introduction of TH, data on its results are limited. METHODS: Our sample population consisted of 40 children with a history of hypoxic-ischemic encephalopathy (HIE) treated with TH, with an average age of 6.25 years (range 5.5, 7.33), 24 (60%) males; and 33 peers with an average age of 8.8 years (6.08, 9.41), 17 (51%) males. Long-term follow-up data belong to two centers in Padova and Torino. We measured general intelligence (WPPSI-III or WISC-IV) and neuropsychological functioning (language, attention, memory, executive functions, social skills, visual motor abilities). We also administered questionnaires to their parents on the children's psychopathological profiles and parental stress. RESULTS: We found differences between groups in several cognitive and neuropsychological domains: intelligence, visuomotor skills, executive functions, and attention. Interestingly, IQ test results effectively differentiated between the groups (HIE vs. controls). Furthermore, the incidence of psychopathology appears to be significantly higher in children with HIE (35%) than in control peers (12%). CONCLUSIONS: Our study supports previous findings on a higher incidence of neuropsychological, cognitive, and psychopathological sequelae after HIE treated with TH. As hypothesized, TH does not appear to ameliorate the outcome after neonatal HIE in those children who survive without major sequelae.

Resting-state functional brain connectivity predicts cognitive performance: An exploratory study on a time-based prospective memory task.

Resting-state functional brain connectivity (rsFC) is in wide use for the investigation of a variety of cognitive neuroscience phenomena. In the first phase of this study, we explored the changes in EEG-reconstructed rsFC in young vs. older adults, in the both the open-eyes (OE) and the closed-eyes (CE) conditions. The results showed significant differences in several rsFC network metrics in the two age groups, confirming and detailing established knowledge that aging modulates brain functional organisation. In the study's second phase we investigated the role of rsFC architecture on cognitive performance through a time-based Prospective Memory task involving participants who monitored the passage of time to perform a specific action at an appropriate time in the future. Regression models revealed that the monitoring strategy (i.e. the number of clock checks) can be predicted by rsFC graph metric, specifically, eccentricity and betweenness in the OE condition, and assortativity in the CE condition. These results show for the first time how metrics qualifying functional brain connectivity at rest can account for the differences in the way individuals strategically handle cognitive loads in the Prospective Memory domain.

Ketonemia and Glycemia Affect Appetite Levels and Executive Functions in Overweight Females During Two Ketogenic Diets.

OBJECTIVE: This study sought to investigate how glycemia and ketonemia variations during two ketogenic diet protocols affect appetite, executive functions, and mood in young women with overweight. METHODS: Fifty healthy young females with overweight were randomly assigned to (1) a ketogenic diet without any restriction on energy intake, (2) a commercial energy-restricted ketogenic Mediterranean diet, and (3) an energy-restricted Mediterranean diet for 10 days. A visual analogue scale was used to test appetite, and one mood test and two cognitive tasks (working memory and inhibition control) were performed. Moreover, body composition, fasting blood glucose, and ß-hydroxybutyrate (BHB) were measured. RESULTS: A positive correlation was found between glycemia and appetite (P = 0.019), unfullness score (P = 0.001), and desire to eat (P = 0.030) (pre- and postdiet levels). Postdiet BHB levels showed a positive correlation with fullness score (P = 0.002) and a negative correlation with appetite (P = 0.022) and desire to eat (P = 0.009). A positive correlation was found between prediet levels of glycemia and reaction times in the go-trials of the executive function test (P = 0.018). Postdiet BHB level showed a negative correlation with the accuracy of the no-go trials (P = 0.027). CONCLUSIONS: Ketogenic diets, compared with a Mediterranean diet, have a greater effect in terms of appetite reduction but might affect inhibition functions.

Diagnosis and Treatment of Developmental Dyslexia and Specific Learning Disabilities: Primum Non Nocere.

Specific learning disabilities (SLDs) are increasingly being addressed by researchers, schools, and institutions, as shown by the increasing number of publications, guidelines, and incidence statistics. Although SLDs are becoming a major topic in education with the final goal of inclusive schools, consistent drawbacks may emerge, resulting in disadvantages instead of benefits for some children. Overdiagnosis and unnecessary interventions may harm children's neurodevelopment and families' quality of life more than previously thought. In this commentary, we discuss recent understandings, their practical and educational applications, and some considerations of the effects of these choices on children.

Comparison of temporal judgments in sighted and visually impaired children.

AIM: We studied visually impaired and blind children to investigate the effects of visual damage on time perception. METHODS: Sixty-three children (11 blind, 16 visually impaired, 20 sighted and 16 sighted but blindfolded) performed a temporal bisection task, which consisted of judging different temporal intervals presented in the auditory modality. RESULTS: The visually impaired children showed lower constant error than sighted children but higher variability (Weber ratio). The blindfolded children had a temporal estimation comparable to the clinical groups and time sensitivity comparable to the controls. CONCLUSION: These findings are interpreted in the light of inter-modality interference, assuming that the coexistence of both sensory modalities, present only in controls, leads to a trade-off between the two senses with an indirect contribution of sight, which does not happen either in the clinical groups or in the blindfolded children, despite the single sensory task.

Selective activation of the superior frontal gyrus in task-switching: an event-related fNIRS study.

In the task-switching paradigm, reaction time is longer and accuracy is worse in switch trials relative to repetition trials. This so-called switch cost has been ascribed to the engagement of control processes required to alternate between distinct stimulus-response mapping rules. Neuroimaging studies have reported an enhanced activation of the human lateral prefrontal cortex and the superior frontal gyrus during the task-switching paradigm. Whether neural activation in these regions is dissociable and associated with separable cognitive components of task switching has been a matter of recent debate. We used multi-channel near-infrared spectroscopy (fNIRS) to measure brain cortical activity in a task-switching paradigm designed to avoid task differences, order predictability, and frequency effects. The results showed a generalized bilateral activation of the lateral prefrontal cortex and the superior frontal gyrus in both switch trials and repetition trials. To isolate the activity selectively associated with the task-switch, the overall activity recorded during repetition trials was subtracted from the activity recorded during switch trials. Following subtraction, the remaining activity was entirely confined to the left portion of the superior frontal gyrus. The present results suggest that factors associated with load and maintenance of distinct stimulus-response mapping rules in working memory are likely contributors to the activation of the lateral prefrontal cortex, whereas only activity in the left superior frontal gyrus can be linked unequivocally to switching between distinct cognitive tasks.

Neuropsychological tools to predict conversion from amnestic mild cognitive impairment to dementia. The TREDEM Registry.

Most of the studies about conversion from Mild cognitive impairment (MCI) to dementia have focused on amnestic MCI (aMCI) which is considered a preclinical phase of Alzheimer's disease. The aim of the present study was to identify neuropsychological tools that would best predict conversion from aMCI to dementia. Fifty-five aMCI subjects on the Treviso Dementia Registry were investigated. They underwent a neuropsychological evaluation during their first assessment and again at follow-up. Cox proportional-hazard regression models were created to measure the association between the dependent variable (dementia diagnosis or MCI status maintenance) and the neuropsychological test scores at baseline. The sample (28 women and 27 men; mean age 76.82 ± 5.88 years; education 7.62 ± 3.99 years) was observed for an average time of 2.17 ± 1.25 years. A Cox backward stepwise regression showed that the Rey Auditory Verbal Learning Test, Delayed Recall (p = .041) and Semantic Verbal Fluency tests (p = .031) appear to be useful in predicting conversion to dementia.

Superior parietal cortex and the attention to delayed intention: An rTMS study.

Prospective memory (PM) is the ability to remember to carry out an intention when the appropriate cue occurs. This study aimed to investigate whether the superior parietal cortex is causally involved in PM and, if so, what is its functional role. We applied repetitive transcranial magnetic stimulation (rTMS) to the left and right superior parietal cortex, and we evaluated the TMS effects on two different PM tasks that required to direct the attention towards either the external stimuli ('Monitoring-load' task) or the intention in memory ('Retrospective-load' task). rTMS of left parietal cortex produced a facilitation of PM performance in both tasks. This was coupled by slower responses to the ongoing activity, for left and right parietal stimulation, but selectively in the 'Retrospective-load' condition. The present results suggest that superior parietal cortex is causally involved in biasing top-down attentional resources between the external, ongoing stimuli and the internal, PM intentions. The possible physiological mechanisms underlying the TMS-related improvement in PM performance are discussed.

Effects of cue focality on the neural mechanisms of prospective memory: A meta-analysis of neuroimaging studies.

Remembering to execute pre-defined intentions at the appropriate time in the future is typically referred to as Prospective Memory (PM). Studies of PM showed that distinct cognitive processes underlie the execution of delayed intentions depending on whether the cue associated with such intentions is focal to ongoing activity processing or not (i.e., cue focality). The present activation likelihood estimation (ALE) meta-analysis revealed several differences in brain activity as a function of focality of the PM cue. The retrieval of intention is supported mainly by left anterior prefrontal cortex (Brodmann Area, BA 10) in nonfocal tasks, and by cerebellum and ventral parietal regions in focal tasks. Furthermore, the precuneus showed increased activation during the maintenance phase of intentions compared to the retrieval phase in nonfocal tasks, whereas the inferior parietal lobule showed increased activation during the retrieval of intention compared to maintenance phase in the focal tasks. Finally, the retrieval of intention relies more on the activity in anterior cingulate cortex for nonfocal tasks, and on posterior cingulate cortex for focal tasks. Such focality-related pattern of activations suggests that prospective remembering is mediated mainly by top-down and stimulus-independent processes in nonfocal tasks, whereas by more automatic, bottom-up, processes in focal tasks.

Neural bases of prospective memory: a meta-analysis and the "Attention to Delayed Intention" (AtoDI) model.

Remembering to realize delayed intentions is a multi-phase process, labelled as prospective memory (PM), and involves a plurality of neural networks. The present study utilized the activation likelihood estimation method of meta-analysis to provide a complete overview of the brain regions that are consistently activated in each PM phase. We formulated the 'Attention to Delayed Intention' (AtoDI) model to explain the neural dissociation found between intention maintenance and retrieval phases. The dorsal frontoparietal network is involved mainly in the maintenance phase and seems to mediate the strategic monitoring processes, such as the allocation of top-down attention both towards external stimuli, to monitor for the occurrence of the PM cues, and to internal memory contents, to maintain the intention active in memory. The ventral frontoparietal network is recruited in the retrieval phase and might subserve the bottom-up attention captured externally by the PM cues and, internally, by the intention stored in memory. Together with other brain regions (i.e., insula and posterior cingulate cortex), the ventral frontoparietal network would support the spontaneous retrieval processes. The functional contribution of the anterior prefrontal cortex is discussed extensively for each PM phase.

It's a Matter of Mind! Cognitive Functioning Predicts the Athletic Performance in Ultra-Marathon Runners.

The present study was aimed at exploring the influence of cognitive processes on performance in ultra-marathon runners, providing an overview of the cognitive aspects that characterize outstanding runners. Thirty runners were administered a battery of computerized tests right before their participation in an ultra-marathon. Then, they were split according to the race rank into two groups (i.e., faster runners and slower runners) and their cognitive performance was compared. Faster runners outperformed slower runners in trials requiring motor inhibition and were more effective at performing two tasks together, successfully suppressing the activation of the information for one of the tasks when was not relevant. Furthermore, slower runners took longer to remember to execute pre-defined actions associated with emotional stimuli when such stimuli were presented. These findings suggest that cognitive factors play a key role in running an ultra-marathon. Indeed, if compared with slower runners, faster runners seem to have a better inhibitory control, showing superior ability not only to inhibit motor response but also to suppress processing of irrelevant information. Their cognitive performance also appears to be less influenced by emotional stimuli. This research opens new directions towards understanding which kinds of cognitive and emotional factors can discriminate talented runners from less outstanding runners.

Early markers of neural dysfunction and compensation: a model from minimal hepatic encephalopathy.

OBJECTIVE: The Inhibitory Control Task (ICT) was used to detect minimal hepatic encephalopathy (MHE). ICT assesses attention, working memory and inhibition by evaluating performance in detect, go and nogo trials, respectively. The event-related potentials (ERPs) elicited by the ICT provide insight into neural mechanisms underlying the cognitive alterations associated with MHE. METHODS: The performance and the ERPs elicited by ICT were measured in 31 patients with cirrhosis (13 with and 18 without MHE) and in 17 controls. The latency and amplitude of the N2, P3a, P3b and nogo-P3 were compared among the groups. RESULTS: Patients with MHE performed worse in all ICT trials compared to patients without MHE and controls. Cirrhotic patients, both with and without MHE, displayed a reduction in P3a amplitude, selectively in the detect trials. Patients without MHE exhibited greater N2 and nogo-P3 amplitudes compared to patients with MHE and controls. CONCLUSIONS: Both patients with and without MHE displayed neural alterations reflecting attentional deficits (i.e., P3a attenuation). However, patients without MHE coped with such dysfunctions by recruiting compensatory neural mechanisms, as suggested by the enhancement of the nogo-P3 and N2 amplitudes coupled with a normal ICT performance. SIGNIFICANCE: The study suggests how initial brain dysfunction might be compensated for by recruitment of additional neurocognitive resources.