Atypical cerebral lateralisation in adults with compensated developmental dyslexia demonstrated using functional transcranial Doppler ultrasound

Functional transcranial Doppler ultrasound (fTCD) is a relatively new and non-invasive technique that assesses cerebral lateralisation through measurements of blood flow velocity in the middle cerebral arteries. In this study fTCD was used to compare functional asymmetry during a word generation task between a group of 30 dyslexic adults and a group of 30 non-dyslexic individuals. In light of previous evidence of atypical laterality in dyslexia, a reduced leftward asymmetry was predicted and confirmed. We know from previous research that most people with atypical language lateralisation have normal language and literacy skills: nevertheless, our results confirm that language laterality is reduced in those with dyslexia. Theoretical explanations for this apparent conundrum are discussed.     

Rapid cerebral hemodynamic modulation during set shifting: Evidence of time-locked associations with cognitive control in females

Set shifting provokes specific alterations of cerebral hemodynamics in basal cerebral arteries. However, no gender differences have been reported. In the following functional transcranial Doppler study, we introduced cerebral hemodynamic modulation to the aspects of set shifting during Wisconsin Card Sorting Test (WCST). Twenty-one subjects underwent the WCST during insonation of the middle cerebral arteries. We examined gender effects on task performance and cerebral hemodynamic modulation. Further, we investigated the linkage between performance and cerebral hemodynamic modulation. In females, maximum positive modulation was restricted to the behaviorally relevant time point of set shifting, and there were time-locked associations between mental slowing during set shifting and rapid cerebral hemodynamic modulation exclusively in females. This study provides evidence of gender-related cerebral hemodynamic modulation during set shifting, and we detected time-locked brain–behavior relationship during cognitive control in females.     

Atypical speech lateralization in adults with developmental coordination disorder demonstrated using functional transcranial Doppler ultrasound

Research using clinical populations to explore the relationship between hemispheric speech lateralization and handedness has focused on individuals with speech and language disorders, such as dyslexia or specific language impairment (SLI). Such work reveals atypical patterns of cerebral lateralization and handedness in these groups compared to controls. There are few studies that examine this relationship in people with motor coordination impairments but without speech or reading deficits, which is a surprising omission given the prevalence of theories suggesting a common neural network underlying both functions. We use an emerging imaging technique in cognitive neuroscience; functional transcranial Doppler (fTCD) ultrasound, to assess whether individuals with developmental coordination disorder (DCD) display reduced left‐hemisphere lateralization for speech production compared to control participants. Twelve adult control participants and 12 adults with DCD, but no other developmental/cognitive impairments, performed a word‐generation task whilst undergoing fTCD imaging to establish a hemispheric lateralization index for speech production. All participants also completed an electronic peg‐moving task to determine hand skill. As predicted, the DCD group showed a significantly reduced left lateralization pattern for the speech production task compared to controls. Performance on the motor skill task showed a clear preference for the dominant hand across both groups; however, the DCD group mean movement times were significantly higher for the non‐dominant hand. This is the first study of its kind to assess hand skill and speech lateralization in DCD. The results reveal a reduced leftwards asymmetry for speech and a slower motor performance. This fits alongside previous work showing atypical cerebral lateralization in DCD for other cognitive processes (e.g., executive function and short‐term memory) and thus speaks to debates on theories of the links between motor control and language production.     

An exploratory analysis of the influence of personality and emotional factors on cerebral blood flow responses during painful stimulation in Fibromyalgia

This study explored the influence of certain personality traits (neuroticism, extraversion, psychoticism, alexithymia), emotional variables (depression, catastrophizing), and insomnia on cerebral blood flow (CBF ) responses to painful stimulation in fibromyalgia, using functional transcranial Doppler sonography. CBF velocities were recorded bilaterally in the anterior cerebral arteries (ACA ) and middle cerebral arteries (MCA ) of 24 fibromyalgia patients during exposure to two painful pressure conditions: (1) fixed pressure (2.4 kg) and (2) an individually calibrated pressure to produce an equal‐moderate subjective pain intensity in all participants (average, 3.5 kg). Psychological factors were assessed by means of questionnaires. Neuroticism, and the externally‐oriented thinking dimension of alexithymia were positively, and extraversion was inversely, associated with specific components of ACA and MCA CBF responses. Regarding catastrophizing and depression, correlations were positive for the fixed pressure condition and negative for the equal subjective intensity condition. The findings suggest that alterations in central nervous pain processing in fibromyalgia vary according to psychological factors. While most of the observed associations reflect a linear increase in nociceptive processing with the magnitude of negative cognitive and emotional states, the inverse associations for catastrophizing and depression during more intense painful stimulation may be ascribed to anti‐nociceptive effects due to activation of the defense reflex.     

Hydrocortisone infusion exerts dose- and sex-dependent effects on attention to emotional stimuli

Glucocorticoid administration has been shown to exert complex effects on cognitive and emotional processing. In the current study we investigated the effects of glucocorticoid administration on attention towards emotional words, using an Affective Go/No-go task on which healthy humans have shown an attentional bias towards positive as compared to negative words. Healthy volunteers received placebo and either low-dose (0.15 mg/kg) or high-dose (0.45 mg/kg) hydrocortisone intravenously during two separate visits in a double-blind, randomized design. Seventy-five minutes post-infusion, the subjects performed tests of attention (Rapid Visual Information Processing [RVIP]), spatial working memory (Spatial Span) and emotional processing (Affective Go/No-go task [AGNG]). On the attention task, performance was impaired under both hydrocortisone doses relative to placebo, though the effect on error rate was not significant after controlling for age; Spatial Span performance was unaffected by hydrocortisone administration. On the AGNG task, relative to the placebo condition the low-dose hydrocortisone infusion decreased response time to emotional words while high-dose hydrocortisone increased response time. In the females specifically, both high and low dose hydrocortisone administration attenuated the normal attentional bias toward positively valenced words. These data suggest that, in healthy women, the modulation of attention by the emotional salience of stimuli is influenced by glucocorticoid hormone concentrations.     

Forming Composites of Cognitive Ability and Alternative Measures to Predict Job Performance and Reduce Adverse Impact: Corrected Estimates and Realistic Expectations

Although there has been empirical attention paid to the criterion‐related validity of predictor composites, there has been much less attention paid to the standardized ethnic group differences associated with these composites. One important area of inquiry in predictor composite research is the influence of adding predictors to a test of general mental ability. The limited empirical literature on this practice is mixed, but the prevailing expectation is that there is likely to be higher validity and less adverse impact. Unfortunately, much of the previous work is limited by the presence of inaccurate validity and standardized ethnic group difference values. In this analysis we formed meta‐analytic matrices to more accurately estimate the validity and standardized ethnic group differences of several composites that combine a measure of cognitive ability with measures of conscientiousness, a structured interview, or biodata. While results were somewhat complex, we found that adding alternative predictors does not result in a situation in which validity automatically goes up and adverse impact potential automatically goes down. In fact, the reductions in adverse impact (if any) from adding “non‐cognitive” predictors were more modest than much of the literature suggests.     

Multi-tasking deteriorates trunk movement control during and after obstacle avoidance

Dynamic and cognitive multi-tasking might affect balance and walking negatively and increase risk of falling. Trunk movement control is critical for balance maintenance and fall-prevention. The impact of multi-tasking on trunk movement control has not been thoroughly studied. In a challenging dynamic multi-tasking condition such as walking and obstacle avoidance, presence of a cognitive task not only increases risk of tripping but also may increase risk of falling by deteriorating trunk control. Our objective was to investigate the impacts of a challenging dynamic and cognitive multi-tasking condition (walking + obstacle avoidance + cognitive task) on trunk kinematics and kinetics and compare those with other joints/segments. Trunk, pelvis, hip, knee, and ankle kinematics and kinetics of 12 young adults were compared between joints/segments and conditions. During walking and obstacle avoidance (dynamic multi-tasking), the trunk had the largest normalized increase in peak flexion angle and extension torque compared to walking, among the other joints/segments. The presence of a cognitive task during walking and obstacle avoidance (dynamic and cognitive multi-tasking) did not impact any of the joints/segments biomechanics except the trunk peak extension torque that was increased. Furthermore, trunk kinematics showed the largest residual differences (post-effects) in 3 cycles after obstacle avoidance compared to walking. The presence of a cognitive task (dynamic and cognitive multi-tasking) did not impact the post-effects of obstacle avoidance on any joints/segments except the trunk with its residual difference from normal walking further increased. These results suggest that a cognitive task deteriorates trunk control and interferes with the ability to regain normal trunk biomechanics after obstacle avoidance. In summary, the trunk requires the largest biomechanical adjustments in a challenging dynamic and cognitive multi-tasking condition where there is a risk of falling. Our study provides baseline results suggesting that trunk control demands more attention and is more negatively affected by dynamic and cognitive multi-tasking. Our results raise a concern for elderly population as their trunk control is already impaired and common daily multi-tasking could further deteriorate their trunk control and increase fall risk.     

Male and female guppies differ in speed but not in accuracy in visual discrimination learning

In many species, males and females have different reproductive roles and/or differ in their ecological niche. Since in these cases the two sexes often face different cognitive challenges, selection may promote some degree of cognitive differentiation, an issue that has received relatively little attention so far. We investigated the existence of sex differences in visual discrimination learning in the guppy, Poecilia reticulata, a fish species in which females show complex mate choice based on male colour pattern. We tested males and females for their ability to learn a discrimination between two different shapes (experiment 1) and between two identical figures with a different orientation (experiment 2). In experiment 3, guppies were required to select an object of the odd colour in a group of five objects. Colours changed daily, and therefore, the solution for this task was facilitated by concept learning. We found males’ and females’ accuracy practically overlapped in the three experiments, suggesting that the two sexes have similar discrimination learning abilities. Yet, males showed faster decision time than females without any evident speed–accuracy trade-off. This result indicates the existence of consistent between-sex differences in decision speed perhaps due to impulsivity rather than speed in information processing. Our results align with previous literature, indicating that sex differences in cognitive abilities are the exception rather than the rule, while sex differences in cognitive style, i.e. the way in which an individual faces a cognitive task, are much more common.     

The differences between cerebral dominance patterns in the speed and accuracy of information processing among university students

IntroductionThe subject of cerebral dominance has received great attention by researchers; however, there is a paucity of studies that have examined its relationship to information processing.ObjectiveThe current study aims to reveal the differences between the cerebral dominance patterns (left cerebral dominance, right cerebral dominance, integrated parallel cerebral dominance) in the speed and accuracy of information processing.MethodA sample of (182) volunteers university students, (mean age ± SD, 19.92 ± 2.76 years; range, 18–24 years; 68 male, 114 females). The Human Information processing survey was applied to the participants. Each subject was exposed to two elementary cognitive tasks (Stroop task and Eriksen flanker task). Each task included two experimental conditions: first, the congruent condition that reflects the automatic processing of information; second, the incongruent condition that reflects the controlled processing of information.ResultsThe results of the study revealed that there were no differences between the patterns of cerebral dominance in the speed and accuracy of information processing.ConclusionAlthough the relationship between cerebral dominance and information processing is not significant, we need more studies to examine this relationship in other samples and in other experimental conditions.     

超重女性对食物信息加工的注意偏向和记忆偏向

采用与食物图片相关的点探测任务和学习—再认范式考察超重女性对不同热量食物信息的注意偏向和记忆偏向。结果发现：(1) 超重女性对高热量食物信息存在注意警觉—注意脱离困难模式,对低热量食物信息仅表现为注意回避模式。(2) 超重组女性对高热量食物信息的再认正确率显著高于正常体重组,而对低热量食物信息的再认成绩组间差异不显著。研究结果证实了超重女性对高热量食物信息投入更多的认知资源,存在注意偏向和记忆偏向。     

Effects of age on attention level: changes in performance between the ages of 12 and 90

ABSTRACT

The purpose of the present study was to assess the changes in attention level among individuals between the ages of 12 and 90 years. A cross-sectional design was used, with each participant tested once by means of the Mathematics Continuous Performance Test (MATH-CPT). Participants were 496 males and females who were divided into eight age-groups, with each group spanning a period of ten years. Attention level was assessed through comparison with nine variables assessing attention. As people aged, significant reductions in the quality of performance emerged on the five main measures of the MATH-CPT: Two of the four sustained attention variables showed an improvement with age. The peak attention level was in the 30 to a 40-age range, after that, there was a constant decline in the level of attention. The study offers encouraging results with respect to the effect of aging on cognitive functioning and specifically sustained attention.     

Cerebral lateralization and general intelligence: gender differences in a transcranial Doppler study

The present study evaluated cerebral lateralization during Raven's progressive matrices (RPM) paradigm in female and male subjects. Bilateral simultaneous transcranial Doppler (TCD) ultrasound was used to measure mean blood flow velocities (MBFV) in the right and left middle cerebral arteries (MCAs) in 24 (15 females and 9 males) right-handed normal subjects. The female subjects used a left hemisphere strategy, while males used a right hemisphere strategy to successfully solve RPM tasks. This implies that general intelligence is associated with neural systems within one hemisphere that are accessible to a variety of cognitive processes.     

Performance in normal subjects on a novel battery of driving-related sensory-motor and cognitive tests

Currently, there is no international standard for the assessment of fitness to drive for cognitively or physically impaired persons. A computerized battery of driving-related sensory-motor and cognitive tests (SMCTests) has been developed, comprising tests of visuoperception, visuomotor ability, complex attention, visual search, decision making, impulse control, planning, and divided attention. Construct validity analysis was conducted in 60 normal, healthy subjects and showed that, overall, the novel cognitive tests assessed cognitive functions similar to a set of standard neuropsychological tests. The novel tests were found to have greater perceived face validity for predicting on-road driving ability than was found in the equivalent standard tests. Test—retest stability and reliability of SMCTests measures, as well as correlations between SMCTests and on-road driving, were determined in a subset of 12 subjects. The majority of test measures were stable and reliable across two sessions, and significant correlations were found between on-road driving scores and measures from ballistic movement, footbrake reaction, hand-control reaction, and complex attention. The substantial face validity, construct validity, stability, and reliability of SMCTests, together with the battery’s level of correlation with on-road driving in normal subjects, strengthen our confidence in the ability of SMCTests to detect and identify sensory-motor and cognitive deficits related to unsafe driving and increased risk of accidents.     

Effects of chewing on cognitive processing speed

In recent years, chewing has been discussed as producing effects of maintaining and sustaining cognitive performance. We have reported that chewing may improve or recover the process of working memory; however, the mechanisms underlying these phenomena are still to be elucidated. We investigated the effect of chewing on aspects of attention and cognitive processing speed, testing the hypothesis that this effect induces higher cognitive performance. Seventeen healthy adults (20–34 years old) were studied during attention task with blood oxygenation level-dependent functional (fMRI) at 3.0 T MRI. The attentional network test (ANT) within a single task fMRI containing two cue conditions (no cue and center cue) and two target conditions (congruent and incongruent) was conducted to examine the efficiency of alerting and executive control. Participants were instructed to press a button with the right or left thumb according to the direction of a centrally presented arrow. Each participant underwent two back-to-back ANT sessions with or without chewing gum, odorless and tasteless to remove any effect other than chewing. Behavioral results showed that mean reaction time was significantly decreased during chewing condition, regardless of speed-accuracy trade-off, although there were no significant changes in behavioral effects (both alerting and conflict effects). On the other hand, fMRI analysis revealed higher activations in the anterior cingulate cortex and left frontal gyrus for the executive network and motor-related regions for both attentional networks during chewing condition. These results suggested that chewing induced an increase in the arousal level and alertness in addition to an effect on motor control and, as a consequence, these effects could lead to improvements in cognitive performance.     

Writing as a meaningful activity

Writing processes have been studied extensively from the cognitive point of view, but little attention has been given to the affective aspects of this activity. In fact, writing experience seems to be relevant to a person not only because it is a complex cognitive activity, but also because it often has an affective characterization. The aim of the present study was to investigate writing as a meaningful activity, that is, to analyze the way in which pupils of different grade levels construe this activity. The study was divided into two phases: (a) interviews with pupils in order to select relevant elements (i.e., writing situations and contexts) and (b) subjects' elicitation of constructs and evaluation of elements. From the qualitative and quantitative analyses of the grids, a developmental trend emerged. Whereas the younger subjects frequently elicited constructs related to the affective dimension of writing, as age increased, the cognitive dimension became more evident.     

Heart work after errors: Behavioral adjustment following error commission involves cardiac effort

Posterror slowing (PES) is the observation that people respond slower on trials subsequent to error commissions than on trials subsequent to correct responses. Different accounts have been proposed to explain PES. On the one hand, it has been suggested that PES arises from an adaptive increase in cognitive control following error commission, thereby making people more cautious after making an error. On the other hand, PES has been attributed to an orienting response, indicating that attention is shifted toward the error. In the present study we tested these accounts by investigating the effects of error commission in both flanker and switch tasks on two task-evoked cardiac measures: the interbeat interval—that is, the interval between two consecutive R peaks—and the RZ interval—that is, the interval between the R peak and the Z point—as measured using electro- and impedance cardiography, respectively. These measures allowed us to measure cardiac deceleration (autonomic orienting) and cardiac effort mobilization, respectively. Our results revealed a shorter RZ interval during posterror trials, indicating increased effort mobilization following errors. In addition, we replicated earlier studies that have shown cardiac slowing during error trials. However, multilevel analyses showed that only the posterror decrease in RZ interval predicted posterror reaction times, whereas there was no positive relationship between error-related cardiac deceleration and posterror reaction times. Our results suggest that PES is related to increased cardiac effort, supporting a cognitive-control account of PES.     

Cognitive and neuropsychological outcomes: more than IQ scores

Improved survival in preterm infants has broadened interest in cognitive and neuropsychological outcomes. The incidence of major disabilities (moderate/severe mental retardation, neurosensory disorders, epilepsy, cerebral palsy) has remained consistent, but high prevalence/low severity dysfunctions (learning disabilities, ADHD, borderline mental retardation, specific neuropsychological deficits, behavioral disorders) have increased. The follow-up literature contains methodologic problems that make generalizations regarding outcome difficult, and these are discussed. Although mean IQs of former VLBW infants generally are in the low average range and are 3-9 points below normal birth weight peers, these scores mask subtle deficits in: visual-motor and visual-perceptual abilities, complex language functions, academics (reading, mathematics, spelling and writing), and attentional skills. There is an increased incidence of non-verbal learning disabilities, need for special educational assistance, and behavioral disorders in children born prematurely. Males have more problems, and there is a trend for worsening outcome over time, due to emergence of more subtle deficits in response to increased performance demands. In addition to IQ and achievement testing in follow-up, there should be evaluation of executive functions and attention, language, sensorimotor functions, visuospatial processes, memory and learning, and behavioral adjustment.     

Intelligence and neural efficiency: The influence of task content and sex on the brain–IQ relationship

In studying physiological correlates of human intelligence, new brain imaging techniques like positron emission tomography (PET) and electroencephalography (EEG) mapping methods focus on the level and topographical distribution of cortical activation. Actually, there is strong empirical evidence that more intelligent individuals display a more focused cortical activation during cognitive performance resulting in lower total brain activation than in less intelligent individuals (i.e., neural efficiency hypothesis). Former studies have used only single, homogeneous tasks and most of the studies have been performed using males. Therefore, here the influence of different task content and of sex on the relationship between intelligence and cortical activation has been tested. In a sample of 26 males and 25 females, we administered verbal, numerical, and figural versions of a well-known elementary cognitive task, the so-called Posner task. Our results suggest a comparatively low cortical activation in brighter as compared to less intelligent individuals but this expected neural efficiency pattern interacted with sex and task content: In the verbal Posner task, the females were more likely to produce cortical activation patterns in line with the neural efficiency hypothesis, whereas in the figural task, primarily the males displayed the expected inverse relationship between IQ and cortical activation.     

An assessment of the attention demands during random- and blocked-practice schedules

The reported study used the dual-task methodology to assess the attention demands associated with high and low contextual interference (CI) practice environments. Two specific issues were addressed. First, is there a difference in the attention demands during random and blocked schedules of practice? Second, what is the time course of any differential attention demands that emerge during random and blocked training? In order to address these questions two specific temporal loci were probed during practice: a pre-response interval and the inter-trial interval. It was assumed that the pre-response interval contained the reconstructive activity that is central to the reconstruction position. In contrast, the inter-trial interval has been interpreted in previous work to be the interval in which critical intra- and inter-item processing is performed during random practice. The data revealed a typical CI effect for the primary key-pressing task. Specifically , blocked-practice participants displayed superior performance during training but performed less well than the random-practice individuals at the time of retention. The poorer acquisition performance of the random practice participants was associated with higher cognitive demand during both the pre-response and the inter-trial intervals than that of individuals assigned to blocked practice. The greater attention demands for random-practice individuals are discussed with respect to processes that might occur in both the pre-response and the inter-trial intervals.