Inhibitory Task Research Articles

Measuring Implicit Biases About Disability: A Scoping Review

Implicit biases about disability contribute to discriminatory behaviors and explicit attitudes toward people with disability, an issue that is of significant importance for rehabilitation researchers. The current study reviewed existing measures of implicit disability biases published between 2000 and April 2022. The search was conducted among seven databases, five major rehabilitation counseling journals, and relevant references in the retrieved articles. A total of 66 studies were identified and reviewed. Results showed that the implicit association test (IAT) was the most frequently used measure of implicit disability biases. A few studies used priming tasks, inhibition tasks, and other tasks based on rating scales to measure implicit disability biases. The strengths and limitations of the measures are discussed, and recommendations for rehabilitation practitioners, educators, and researchers are provided.

B - 03 Inhibitory Control and Saccadic Eye Movement in Adults with Attention-Deficit Hyperactivity Disorder: an Eye-Tracking Analysis.

The objective of this study was to investigate oculomotor differences between adults with and without attention-deficit hyperactivity disorder (ADHD) during a computerized response inhibition task, utilizing eye-tracking technology. Twenty-nine adults with ADHD and 35 controls (ages 18-32) were recruited from Sona Systems and the Learning Center at a university. Participants completed 120 randomized trials of the flanker task while their eye movements were monitored. Saccadic eye movement was investigated, while reaction time and performance errors were recorded from the flanker task. Participants with ADHD were required to refrain from taking stimulant medication the day of the experiment. A linear mixed-effects regression model was fitted. Having ADHD resulted in significantly slower response times, t(57) = 2.73, p < 0.005, 95% CI [0.04, 0.27], but not significantly more errors than control participants on the flanker task. There were no significant differences in the number of saccades between groups. Further analysis demonstrated that adults with ADHD had a significantly higher number of saccades as the number of trials increased, t(7019) = 3.69, p < 0.001, 95% CI [0.00105, 0.00314]. Slower reaction time in adults with ADHD during the flanker task indicates slower processing, but this did not affect their accuracy. While no differences were found in the number of saccades between groups, higher saccades as trial number increased in adults with ADHD suggests possible fatigue contributing to oculomotor differences. Further research is necessary to investigate potential gaze differences during a task that necessitates increased saccadic eye movement.

A - 67 Does Cognitive Set-Shifting in Multilinguals Serve as a Protective Factor against Depressive Rumination?

The purpose of this study is to assess whether multilinguals' advantage in cognitive flexibility serves as a protective factor against ruminative tendencies common in depressed mood. We compared monolinguals and multilinguals in a backward inhibition task during negative and neutral moods. It was hypothesized that monolinguals compared with multilinguals would perform worse on inhibition trials compared to control when induced into a negative mood. 96 undergraduates from Queens College, a population with high linguistic diversity, were recruited from Psychology 101 courses. Participants were monolingual (n = 47) or multilingual (2+ languages; n = 49). Participants responded to questions about their language and social background before undergoing mood induction to either neutral or negative (sad) affective states. They then completed a computerized cognitive set-shifting task measuring reaction time (RT) and accuracy. A two-way ANOVA was conducted examining the effect of mood condition and mono/multilingualism status on RT and accuracy on the set-switching task for backward inhibition trials. There was a statistically significant interaction between the effects of mood condition and mono/multilingualism on RT, F(1, 92) =6.062, p = 0.002, such that multilinguals had a higher RT compared to monolinguals when induced into a negative mood. The main effects of mono/multilingualism and mood condition were not statistically significant. Difference in accuracy between groups was not statistically significant. Contrary to our hypothesis, bilinguals took longer to respond than monolinguals in a sad mood, specifically for lag inhibition trials. Additional research is needed to determine how sociocultural factors may explain multilinguals' slowed response in a negative mood.

The suppression task and first‐order predicate calculus

AbstractThe suppression task challenges classical logic. Classical logic is monotonic. However, in the suppression task, an inference with the form of modus ponendo ponens is inhibited by adding a new premise. Several explanations have been given to account for this fact. The present paper indicates three of them as examples: that of the theory of mental models, that based on logic programming and closed world assumption, and that referring to Carnap's concept of state‐descriptions. Besides, the paper offers one more explanation linked to Carnap's idea of reduction. It proposes sentences akin to a reduction sentence, a pair reduction, and a bilateral reduction sentence. Those sentences are related to the initial conditional in the suppression task. This proposal tries to stay within first‐order predicate logic.

Locus Coeruleus Integrity Is Linked to Response Inhibition Deficits in Parkinson's Disease and Progressive Supranuclear Palsy.

Parkinson's disease (PD) and progressive supranuclear palsy (PSP) both impair response inhibition, exacerbating impulsivity. Inhibitory control deficits vary across individuals and are linked with worse prognosis, and lack improvement on dopaminergic therapy. Motor and cognitive control are associated with noradrenergic innervation of the cortex, arising from the locus coeruleus (LC) noradrenergic system. Here we test the hypothesis that structural variation of the LC explains response inhibition deficits in PSP and PD. Twenty-four people with idiopathic PD, 14 with PSP-Richardson's syndrome, and 24 age- and sex-matched controls undertook a stop-signal task and ultrahigh field 7T magnetization-transfer-weighted imaging of the LC. Parameters of "race models" of go- versus stop-decisions were estimated using hierarchical Bayesian methods to quantify the cognitive processes of response inhibition. We tested the multivariate relationship between LC integrity and model parameters using partial least squares. Both disorders impaired response inhibition at the group level. PSP caused a distinct pattern of abnormalities in inhibitory control with a paradoxically reduced threshold for go responses, but longer nondecision times, and more lapses of attention. The variation in response inhibition correlated with the variability of LC integrity across participants in both clinical groups. Structural imaging of the LC, coupled with behavioral modeling in parkinsonian disorders, confirms that LC integrity is associated with response inhibition and LC degeneration contributes to neurobehavioral changes. The noradrenergic system is therefore a promising target to treat impulsivity in these conditions. The optimization of noradrenergic treatment is likely to benefit from stratification according to LC integrity.SIGNIFICANCE STATEMENT Response inhibition deficits contribute to clinical symptoms and poor outcomes in people with Parkinson's disease and progressive supranuclear palsy. We used cognitive modeling of performance of a response inhibition task to identify disease-specific mechanisms of abnormal inhibitory control. Response inhibition in both patient groups was associated with the integrity of the noradrenergic locus coeruleus, which we measured in vivo using ultra-high field MRI. We propose that the imaging biomarker of locus coeruleus integrity provides a trans-diagnostic tool to explain individual differences in response inhibition ability beyond the classic nosological borders and diagnostic criteria. Our data suggest a potential new stratified treatment approach for Parkinson's disease and progressive supranuclear palsy.

Inhibition and Heart Rate Variability in Experimentally Induced Pain.

Pain is a complex experience that requires executive functions (EFs) to be processed. The autonomic outcome of the neural networks involved in the cognitive evaluation of pain is reflected by heart rate variability (HRV), an index of self-regulation abilities. Although some results suggest a relationship between HRV, EFs, and pain, studies focusing on this three-way relationship are still scarce. This study aims to investigate the relationship between pain, cognitive, and autonomic mechanisms, hypothesizing an association between resting HRV and both cognitive and motor inhibition as indices of executive functioning. This relationship was investigated after an experimental-induced pain. Seventy-six young adults were exposed to the Cold Pressure Arm Warp to induce experimental pain. HRV was collected, and cognitive tasks were administered to assess executive performance. The results showed that (1) HRV indices significantly increased during pain stimulation, (2) cognitive inhibition was positively correlated with vagal indices and with pain parameters, (3) both inhibition tasks significantly predicted pain threshold while the performance on the Stroop Task predicted pain tolerance. Results suggest a three-way relationship. Further research would focus on the role of HRV and cognitive strategies in pain management in chronic pain conditions.

Prefrontal oxygenation varies as a function of response inhibition performance in healthy participants but not in youth with non-suicidal self-injury.

Non-suicidal self-injury (NSSI), a highly prevalent symptom in adolescence, has been associated with impulsivity. Behavioral measures of response inhibition in combination with the recording of brain activity potentially improve the understanding of the etiology of the behavior. We therefore investigated prefrontal cortex (PFC) oxygenation during a response inhibition task using functional near-infrared spectroscopy (fNIRS) in n=152 adolescents with NSSI and n=47 healthy controls. We compared groups regarding behavioral performance and PFC oxygenation and tested whether the association between task performance and PFC oxygenation differed between groups. PFC oxygenation was slightly higher in adolescents with NSSI than in controls. Further, there was evidence for a group by performance interaction: In healthy controls, higher oxygenated hemoglobin was associated with better task performance, which was not the case in the NSSI group. We did not find evidence of associations between PFC oxygenation and clinical measures. Our study provides preliminary evidence of altered brain functional correlates of response inhibition in adolescents with NSSI potentially reflecting deficient top-down regulation of limbic regions through prefrontal regions. Due to methodological limitations of the current study, findings must be interpreted with caution and future studies should optimize task designs for fNIRS processing.

Actions versus Words: Exploring the contributions of working memory and motoric coding in children's instruction following using a dual-task paradigm.

Previous research in adults has showed that physical performance (i.e., enactment) of instructions at recall leads to better memory compared to verbal recall and that this effect does not rely solely on Working Memory resources. The current study aimed to replicate this finding in children. A group of 32 children encoded simple instructions verbally while engaging in a series of distractor tasks (articulatory suppression, backwards counting and a motor suppression task). Participants recalled information verbally or physically through enactment. The findings showed that although distractors impaired performance compared to a control condition (no distractor task), the enactment advantage remained intact in all conditions. These findings show that children's memory is superior when they perform, rather than when they verbally repeat instructions and crucially it is suggested that this effect does not rely solely on Working Memory resources.

Emotional self-body odors do not influence the access to visual awareness by emotional faces.

A growing body of research suggests that emotional chemosignals in others' body odor (BO), particularly those sampled during fearful states, enhance emotional face perception in conscious and preconscious stages. For instance, emotional faces access visual awareness faster when presented with others' fear BOs. However, the effect of these emotional signals in self-BO, that is, one's own BO, is still neglected in the literature. In the present work, we sought to determine whether emotional self-BOs modify the access to visual awareness of emotional faces. Thirty-eight women underwent a breaking-Continuous Flash Suppression task in which they were asked to detect fearful, happy, and neutral faces, as quickly and accurately as possible, while being exposed to their fear, happiness, and neutral self-BOs. Self-BOs were previously collected and later delivered via an olfactometer, using an event-related design. Results showed a main effect of emotional faces, with happy faces being detected significantly faster than fearful and neutral faces. However, our hypothesis that fear self-BOs would lead to faster emotional face detection was not confirmed, as no effect of emotional self-BOs was found-this was confirmed with Bayesian analysis. Although caution is warranted when interpreting these results, our findings suggest that emotional face perception is not modulated by emotional self-BOs, contrasting with the literature on others' BOs. Further research is needed to understand the role of self-BOs in visual processing and emotion perception.

Related neural networks underlie suppression of emotion, memory, motor processes as identified by data-driven analysis

BackgroundGoal-directed behavior benefits from self-regulation of cognitive and affective processes, such as emotional reactivity, memory retrieval, and prepotent motor response. Dysfunction in self-regulation is a common characteristic of many psychiatric disorders, such as PTSD and ADHD. This study sought to determine whether common intrinsic connectivity networks (ICNs; e.g. default mode network) are involved in the regulation of emotion, motor, and memory processes, and if a data-driven approach using independent component analysis (ICA) would successfully identify such ICNs that contribute to inhibitory regulation.MethodsEighteen participants underwent neuroimaging while completing an emotion regulation (ER) task, a memory suppression (Think/No-Think; TNT) task, and a motor inhibition (Stop Signal; SS) task. ICA (CONN; MATLAB) was conducted on the neuroimaging data from each task and corresponding components were selected across tasks based on interrelated patterns of activation. Subsequently, ICNs were correlated with behavioral performance variables from each task.ResultsICA indicated a common medial prefrontal network, striatal network, and frontoparietal executive control network, as well as downregulation in task-specific ROIs.ConclusionsThese results illustrate that common ICNs were exhibited across three distinct inhibitory regulation tasks, as successfully identified through a data-driven approach (ICA).

Elevated representational similarity of voluntary action and inhibition in Tourette syndrome.

Many people with Tourette syndrome are able to volitionally suppress tics, under certain circumstances. To understand better the neural mechanisms that underlie this ability, we used functional magnetic resonance neuroimaging to track regional brain activity during performance of an intentional inhibition task. On some trials, Tourette syndrome and comparison participants internally chose to make or withhold a motor action (a button press), while on other trials, they followed 'Go' and 'NoGo' instructions to make or withhold the same action. Using representational similarity analysis, a functional magnetic resonance neuroimaging multivariate pattern analysis technique, we assessed how Tourette syndrome and comparison participants differed in neural activity when choosing to make or to withhold an action, relative to externally cued responses on Go and NoGo trials. Analyses were pre-registered, and the data and code are publicly available. We considered similarity of action representations within regions implicated as critical to motor action release or inhibition and to symptom expression in Tourette syndrome, namely the pre-supplementary motor area, inferior frontal gyrus, insula, caudate nucleus and primary motor cortex. Strikingly, in the Tourette syndrome compared to the comparison group, neural activity within the pre-supplementary motor area displayed greater representational similarity across all action types. Within the pre-supplementary motor area, there was lower response-specific differentiation of activity relating to action and inhibition plans and to internally chosen and externally cued actions, implicating the region as a functional nexus in the symptomatology of Tourette syndrome. Correspondingly, patients with Tourette syndrome may experience volitional tic suppression as an effortful and tiring process because, at the top of the putative motor decision hierarchy, activity within the population of neurons facilitating action is overly similar to activity within the population of neurons promoting inhibition. However, not all pre-supplementary motor area group differences survived correction for multiple comparisons. Group differences in representational similarity were also present in the primary motor cortex. Here, representations of internally chosen and externally cued inhibition were more differentiated in the Tourette syndrome group than in the comparison group, potentially a consequence of a weaker voluntary capacity earlier in the motor hierarchy to suppress actions proactively. Tic severity and premonitory sensations correlated with primary motor cortex and caudate nucleus representational similarity, but these effects did not survive correction for multiple comparisons. In summary, more rigid pre-supplementary motor area neural coding across action categories may constitute a central feature of Tourette syndrome, which can account for patients' experience of 'unvoluntary' tics and effortful tic suppression.

Combined Unplugged and Educational Robotics Training to Promote Computational Thinking and Cognitive Abilities in Preschoolers

Computational thinking (CT) learning activities are increasingly integrated in early-stage school curricula in several countries. Tools used to teach CT in early school years include unplugged coding—i.e., programming without computing devices—and educational robotics (ER)—i.e., giving instructions to a digitally controlled mechanical robot to perform specific actions in a physical environment. Past studies have shown that training coding skills through ER enhances first graders’ executive functions (EFs). Little is known, however, about the effects of ER interventions, alone or combined with un-plugged activities, on preschoolers’ CT and EF skills. In a cluster-randomized controlled trial, we assessed whether improvements in preschoolers’ coding skills, following interventions based on combinations of unplugged coding and ER, transfer to plugged (computer-based) coding abilities and to EFs such as planning, response inhibition, and visuo-spatial skills. Forty-seven preschoolers from four class groups, with no prior exposure to coding, were randomly assigned to an experimental (unplugged coding and ER, two classes) or control (standard school activities, two classes) instructional groups. Four coding tasks, one standardized planning task (Tower of London test), one standardized response inhibition task (NEPSY-II inhibition subtest), and one visuo-spatial standardized task (Primary Mental Ability subtest) were used to assess children’s skills at the pretest (before the intervention) and posttest (after the intervention). To measure retention, the same skills were also assessed for 22 children from the experimental group 3 months from the posttest (follow up). The paper discusses the results of this experimental intervention. The results show significant positive effects of the instructional program on children’s computer-based coding skills and cognitive abilities, particularly visuo-spatial skills. Between pretest and posttest, children in the experimental group improved in coding, z = 3.84, p = 0.000, r = 0.87, and in visuo-spatial skills, z = 3.09, p = 0.002, r = 0.69. The waiting list control group showed improvements in coding skills only after the intervention, at the assessment point T3, z = 2.99, p = 0.003, r = 0.71. These findings show that practice with tangible and unplugged coding during the last year of preschool not only significantly improves children’s skills to solve computer-based coding problems (near-transfer effect), but it may also have some far-transfer effects on cognitive functions, such as visuo-spatial skills.

The impact of vestibular function on cognitive–motor interference: a case–control study on dual-tasking in persons with bilateral vestibulopathy and normal hearing

Bilateral vestibulopathy (BV) is a chronic vestibular disorder, characterized by bilaterally absent or significantly impaired vestibular function. Symptoms typically include, but are not limited to, unsteadiness and movement-induced blurred vision (oscillopsia). This prospective case–control study aimed to elucidate the impact of BV on cognitive and motor performance and on cognitive–motor interference. Cognitive and motor performance, as well as cognitive–motor interference were measured in persons with BV and normal hearing using the 2BALANCE dual-task protocol. The experimental group was matched to a healthy control group based on age, sex, and educational level. The 2BALANCE protocol comprises cognitive tests assessing visuospatial memory, mental rotation, visual and auditory response inhibition, visual and auditory working memory, and processing speed. The cognitive tests were performed in single-task condition (while seated), and in dual-task condition (during a static and a dynamic motor task). The static motor task consisted of balancing on a force platform with foam pad. The dynamic motor task consisted of walking at a self-selected speed. These motor tasks were also performed in single-task condition. A generalized estimating equations model was used to investigate group differences for all cognitive and motor outcome measures. The estimated marginal means, as well as the odds ratios (OR), and their 95% confidence intervals (CI) were calculated. For the backward digit recall test, a baseline measurement was performed and analyzed using a student-t test. A total of 22 patients with BV and normal hearing and 22 healthy control subjects were assessed [mean age (SD), BV = 53.66 (13.35) and HC = 53.21 (13.35), 68% male]. The BV group had poorer mental rotation skills in single-task condition, compared to the control group [odds ratio (OR) = 2.30, confidence interval (CI) = 1.12–4.73, P = 0.024]. Similarly, auditory and visual working memory were also poorer in the BV group in single-task condition (P = 0.028 and P = 0.003, respectively). The BV group also performed poorer on the mental rotation task and the visual response inhibition task in dual-task condition (OR = 2.96, CI = 1.57–5.59, P < 0.001 and OR = 1.08, CI = 1.01–1.16, P = 0.032, respectively). Additionally, an interaction effect, indicating increased cognitive–motor interference in the BV group, was observed for mental rotation, response inhibition, and auditory working memory (P = 0.003 to 0.028). All static motor outcome parameters indicated more postural sway in the BV group compared to the control group for all test conditions (P < 0.001 to 0.026). No group differences were noted for the dynamic motor task. These findings suggest a link between vestibular function and cognitive performance, as well as a greater interference between cognitive and motor performance in BV, compared to healthy controls.

Post-traumatic stress disorder (PTSD), cognitive control, and perceived seizure control in patients with epilepsy: An exploratory study

Epilepsy is often linked to various psychiatric symptoms, with anxiety, depression, and interictal dysphoric disorders being the most prevalent. Few studies have investigated posttraumatic stress disorder (PTSD) in epilepsy, but they suggest a notable prevalence of PTSD. PTSD is known to be associated with cognitive impairments, particularly memory and executive functions.Our proposed exploratory study aims to investigate executive attentional control and emotional inhibition in patients with drug-resistant epilepsy (DRE) who exhibit PTSD symptoms compared with a healthy control group. Additionally, some PWE can manage their seizures using emotional and cognitive strategies, we find it relevant to explore the connection between their regulation abilities, cognitive control performance, and PTSD symptoms.We included 54 PWE and 60 healthy participants. They completed anxiety and depression scales as well as two questionnaires assessing PTSD symptoms and a questionnaire that measured the perceived self-control of seizures. We measured executive control using an executive control task (Attention Network Test, ANT) and an emotional Go/No-Go task. We found a positive correlation between PTSD scores (PDS-5) and performance at the ANT task. In contrast, in the emotional inhibition (Go/No-Go) task, behavioral inhibition errors were positively correlated with PTSD scores, specifically with hypervigilance symptoms in PTSD+ patients. There was a positive correlation between response reaction times in an aversive condition and PTSD scores: the more severe the PTSD symptoms, the faster the PWE identified stimuli in the angry face condition of the Go/No-Go task. Regarding perceived seizure control, we found correlations between alertness and PTSD symptoms associated with seizure anticipation during the inter- and peri-ictal periods. Patients with PTSD symptoms reported better seizure control.Our findings suggest that epilepsy patients with PTSD experience cognitive changes such as heightened executive attentional control, weakened emotional inhibition, and improved seizure control perception.

Electrophysiological variability during tests of executive functioning: A comparison of athletes with and without concussion and sedentary control participants

Objective Sport participation may benefit executive functioning (EF), but EF can also be adversely affected by concussion, which can occur during sport participation. Neural variability is an emerging proxy of brain health that indexes the brain’s range of possible responses to incoming stimuli (i.e., dynamic range) and interconnectedness, but has yet to be characterized following concussion among athletes. This study examined whether neural variability was enhanced by athletic participation and attenuated by concussion. Method Seventy-seven participants (18–25 years-old) were classified as sedentary controls (n = 33), athletes with positive concussion history (n = 21), or athletes without concussion (n = 23). Participants completed tests of attention switching, response inhibition, and updating working memory while undergoing electroencephalography recordings to index neural variability. Results Compared to sedentary controls and athletes without concussion, athletes with concussion exhibited a restricted whole-brain dynamic range of neural variability when completing a test of inhibitory control. There were no group differences observed for either the switching or working memory tasks. Conclusions A history of concussion was related to reduced dynamic range of neural activity during a task of response inhibition in young adult athletes. Neural variability may have value for evaluating brain health following concussion.

Linking resting state metabolite concentrations in the dorsal anterior cingulate cortex to response inhibition in OCD, a combined fMRI-MRS study

IntroductionObsessive-compulsive disorder (OCD) has been associated with abnormal brain activation in regions related to response inhibition, such as the dorsal anterior cingulate cortex (dACC), as well as dysregulation of the glutamate system. We studied how the neurometabolites glutamate and glutamine (Glx) in the dACC are related to task performance and task-related brain activation during a response inhibition task in OCD patients and healthy controls (HC). MethodsWe combined resting-state magnetic resonance spectroscopy (1H-MRS) in the dACC and functional MRI (fMRI) during the Stop Signal Task (SST), using data from two sites (43 OCD patients and 41 HC). For fMRI data, region of interest (ROI) and whole brain analyses were performed during successful inhibition and error processing. Subsequently, the relation between baseline Glx concentrations, task-related activation, functional connectivity, and task performance was tested using correlational analyses. ResultsIn HC, Glx concentration in dACC showed a positive correlation with inhibition-related activation in the right thalamus (based on ROI analyses) and the brain stem (based on whole brain analyses). No relation between Glx and task-related activation was observed in patients with OCD. SST performance was not different between groups and was not associated with dACC Glx concentrations. LimitationsAlthough we attempted to link neurometabolite levels and brain activation, the non-simultaneous acquisition of 1H-MRS with fMRI made it difficult to interpret the results. ConclusionsWe conclude that dACC Glx is associated with inhibition-related activation and network function in HC, but not in OCD, suggesting altered inhibition processing in OCD.

Irrelevant emotional expressions interfered with response inhibition: the role of contrast emotions

ABSTRACT Irrelevant emotional faces would facilitate or inhibit response inhibition, depending on how these faces are paired with different emotional faces. In previous studies, angry faces were either paired with neutral, happy, or fearful faces in the response inhibition task, potentially leading to mixed results. This is the first study where all four irrelevant emotional faces (happy, angry, fearful, and neutral) were used simultaneously and presented in the same block as a stop-signal in the stop-signal paradigm. Participants were required to respond to the go signals. Occasionally, a stop-signal with irrelevant facial expressions was presented, where participants were required to withhold their motor response. All stop signals with irrelevant emotional facial expressions in comparison to neutral facial expressions interfered with the response inhibition process. Our results extend previous findings by suggesting that approach and avoidance reactions to facial expressions depend on the contrasting emotions presented in the task.

Divergent auditory activation in relation to inhibition task performance in children and adults.

Adults and children show remarkable differences in cortical auditory activation which, in children, have shown relevance for cognitive performance, specifically inhibitory control. However, it has not been tested whether these differences translate to functional differences in response inhibition between adults and children. We recorded auditory responses of adults and school-aged children (6-14 years) using combined magneto- and electroencephalography (M/EEG) during passive listening conditions and an auditory Go/No-go task. The associations between auditory cortical responses and inhibition performance measures diverge between adults and children; while in children the brain-behavior associations are not significant, or stronger responses are beneficial, adults show negative associations between auditory cortical responses and inhibitory performance. Furthermore, we found differences in brain responses between adults and children; the late (~200 ms post stimulation) adult peak activation shifts from auditory to frontomedial areas. In contrast, children show prolonged obligatory responses in the auditory cortex. Together this likely translates to a functional difference between adults and children in the cortical resources for performance consistency in auditory-based cognitive tasks.

The impact of sensation seeking personality trait on acute alcohol-induced disinhibition

BackgroundAcute alcohol-related behavioral disinhibition has been well studied. But whether individual differences in the personality trait sensation seeking affect alcohol-induced behavioral disinhibition remains uncertain. MethodsThe present study used functional near-infrared spectroscopy (fNIRS) technique and a response inhibition task (i.e., Go/No-Go) to determine the impact of the sensation seeking trait on the relationship between acute alcohol administration and inhibitory control capacity, and further investigate the neural mechanisms underlying this behavioral effect. Twenty-five high-sensation seekers and twenty-six low-sensation seekers were enrolled in this study. These participants attended two sessions: once for alcohol intake (0.5g/kg) and once for placebo intake (0g/kg). ResultsOur results showed that high-sensation seekers relative to low-sensation seekers showed a significant decrease in inhibition accuracy under alcohol versus the placebo condition. Moreover, reduced prefrontal activity following acute alcohol consumption was more pronounced in high-sensation seekers compared with low-sensation seekers. ConclusionsThese findings showed that alcohol-induced behavioral disinhibition was affected by the personality trait sensation seeking and that recruitment of the prefrontal cortex contributed to the observed behavioral effect.

Hierarchical coupling control of cable-driven multi-loop crane for underactuated positioning

For the low-cost anti-swing retrofit of existing offshore heavy cranes, a (2-UPPU/UPU)UP multi-loop configuration with six cable-driven prismatic pairs and a UP underactuated pendulum is introduced. Each UPPU branch contains a fast-moving prismatic pair and a slow-moving one. A configuration tracking method utilizing three slow cable motions in 2-UPPU/UPU is proposed by motion compensation technology. A multi-loop underactuated end positioning scheme is given to achieve the cargo's horizontal positioning in inertia frame, i.e., two fast cable motions in 2-UPPU are used to drive four states comprising their tracking trajectories and two cargo swings, which frees the wave compensation and swing suppression task from crane joints and retains the original crane system. A hierarchical coupling controller with a special coupling relation matrix is designed, where the matrix-based sub-controller fusion technique provides a standardized design approach with distinct physical meaning for the application of hierarchical methodology in underactuated multi-loop systems. The stability analysis by Lyapunov method reveals multiple coupling relation matrices matching stability conditions, giving birth to five attractive coupling control modes. Simulations and experiments are conducted to compare and verify performance.