Information Processing Deficits Research Articles

227 Reduced drift rate: a biomarker of impaired information processing in functional movement disorders

Recently the similarity of neuropsychiatric profiles across a range of functional syndromes has been high- lighted. This is suggestive of a common underlying mechanism with a theoretical deficit of information processing proposed. In this study, we took the temporal discrimination threshold, as a paradigm that can be used to model sensory processing in functional movement disorders. Our hypothesis was that we would be able to delineate markers of slowed information processing in this paradigm removed from the phenomenological presentation with a movement disorder. We recorded both response accuracy and reaction time in a two choice temporal resolution/discrimination task in 36 patients with functional movement disorders and 36 controls. We used a well-established model for decision-making (the drift diffusion model) to estimate mechanistic physiological dimensions of decision-making and sensory pro- cessing. This revealed pathologically reduced drift rate in the patient group, a parameter that quantifies the quality and rate of information accumulation within this sensory task (p=0.002). We discuss how the deficits we observed in patients with functional movement disorders are likely to stem from abnormal allocation of attention that impairs the quality of sensory information available. Within a predictive coding framework sensory information could be down-weighted in favour of predictions encoded by the prior. Our results therefore offer a parsimonious account for a range of experimental and clinical findings.asadnick@sgul.ac.uk

Precuneus connectivity and symptom severity in chronic depression✰

Although abnormal resting state connectivity within several brain networks has been repeatedly reported in depression, little is known about connectivity in patients with early onset chronic depression. We compared resting state connectivity in a homogenous sample of 32 unmedicated patients with early onset chronic depression and 40 healthy control participants in a seed-to-voxel-analysis. According to previous meta-analyses on resting state connectivity in depression, 12 regions implicated in default mode, limbic, frontoparietal and ventral attention networks were chosen as seeds. We also investigated associations between connectivity values and severity of depression. Patients with chronic depression exhibited stronger connectivity between precuneus and right pre-supplementary motor area than healthy control participants, possibly reflecting aberrant information processing and emotion regulation deficits in depression. Higher depression severity scores (Hamilton Rating Scale for Depression) were strongly and selectively associated with weaker connectivity between the precuneus and the subcallosal anterior cingulate. Our findings correspond to results obtained in studies including both episodic and chronic depression. This suggests that there may be no strong differences between subtypes of depression regarding the seeds analyzed here. To further clarify this issue, future studies should directly compare patients with different courses of depression.

The frequency-following response to assess the neural representation of spectral speech cues in older adults

Older adults often present difficulties understanding speech that cannot be explained by age-related changes in sound audibility. Psychoacoustic and electrophysiologic studies have linked these suprathreshold difficulties to age-related deficits in the auditory processing of temporal and spectral sound information. These studies suggest the existence of an age-related temporal processing deficit in the central auditory system, but the existence of such deficit in the spectral domain remains understudied. The FFR is an electrophysiological evoked response that assesses the ability of the neural auditory system to reproduce the spectral and temporal patterns of a sound. The main goal of this short review is to investigate if the FFR can identify and measure spectral processing deficits in the elderly compared to younger adults (for both, without hearing loss or competing noise). Furthermore, we want to determine what stimuli and analyses have been used in the literature to assess the neural encoding of spectral cues in older adults. Almost all reviewed articles showed an age-related decline in the auditory processing of spectral acoustic information. Even when using different speech and non-speech stimuli, studies reported an age-related decline at the fundamental frequency, at the first formant, and at other harmonic components using different metrics, such as the response's amplitude, inter-trial phase coherence, signal-to-response correlation, and signal-to-noise ratio. These results suggest that older adults may present age-related spectral processing difficulties, but further FFR studies are needed to clarify the effect of advancing age on the neural encoding of spectral speech cues. Spectral processing research on aging would benefit from using a broader variety of stimuli and from rigorously controlling for hearing thresholds even in the absence of disabling hearing loss. Advances in the understanding of the effect of age on FFR measures of spectral encoding could lead to the development of new clinical tools, with possible applications in the field of hearing aid fitting.

Prepulse inhibition deficits in inbred and outbred rats and between-strain differences in startle habituation do not depend on startle reactivity levels

The acoustic startle response and prepulse inhibition (PPI) of startle are measures related to information processing, which is impaired in schizophrenia. Some studies have provided inconclusive patterns of association between both measures in rodents. We assessed the influence of baseline startle response on PPI in large samples of Roman high-(RHA) and low-avoidance (RLA) rat strains and in genetically heterogeneous stock (HS) rats. Results show that RHAs exhibit a PPI deficit compared to RLA rats, which is present regardless of the startle response levels. HS rats were stratified in two sub-samples according to their high or low PPI (HS-highPPI or HS-lowPPI, respectively) scores, and then they were grouped by their differential baseline startle amplitude (high reactivity –HR- or low reactivity –LR-) within each sub-sample. Differences between high- and low-PPI-stratified HS rats remained regardless of their high or low startle amplitude scores. Thus, the impairments in %PPI found in both RHA and HS-LowPPI rats are present irrespective of the relatively high or low levels of startle amplitude in pulse-alone trials. Another objective of the present study was to evaluate whether habituation to the startling stimulus (i.e., pulse) depends on the initial baseline startle response. RLA rats habituated to the startling stimulus more effectively than RHAs regardless of their baseline startle responses. Conversely, there were no differences in startle habituation in the HS rats grouped by their extreme scores of baseline startle. Altogether, these findings suggest a deficit in information processing in RHA rats, which along with evidence indicating that this strain displays other attentional/cognitive impairments, strengthens the validity of the RHA strain as a putative model of schizophrenia-relevant features.

Common outcome, different pathways: Social information-processing deficits in autism spectrum disorder and attention-deficit/hyperactivity disorder

Common outcome, different pathways: Social information-processing deficits in autism spectrum disorder and attention-deficit/hyperactivity disorder

Common outcome, different pathways: Social information-processing deficits in autism spectrum disorder and attention-deficit/hyperactivity disorder.

Social functioning is a key domain of impairment in both autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). This review adopts the social information-processing model as the theoretical framework to compare and contrast the deficits of ASD and ADHD at each of the six steps of social information-processing. Both disorders show deficits at each step, but the nature and origins of the deficits are different. Thus, while both disorders exhibit a common outcome of social impairment, the exact pathways that each disorder traverses along the six steps of social information-processing are different. For ASD, there is a social knowledge/behaviour deficit arising from difficulties in social/emotional cue detection, encoding, and interpretation, leading to problems in joining and initiating social interaction. For ADHD, there is a performance deficit incurred by disruption arising from the ADHD symptoms of inattention and hyperactivity/impulsivity, while its acquisition capacity on social knowledge is relatively intact. The inattentive, intrusive, and impulsive behaviours of ADHD unsettle social interaction. Finally, this review proposes training targets for intervention along the six steps of the social information-processing model for ASD and ADHD, as well as areas for future research in further elucidating the social impairment of the two disorders.

RELATIONSHIP OF REFRACTION CLAIMS WITH STUDENT ACHIEVEMENT IN SMP NEGERI PADANG CITY

Vision problems related to the learning process include deficits in efficiency and processing of visual information that have the potential to interfere with a person's ability to learn. The purpose of this study was to determine the relationship between refractive errors and student achievement. This type of research is descriptive quantitative. The population in this study was 30 adolescents at SMP Negeri Padang City. The discussion is sorted according to the formulation of the problem. Based on the results of the study, it was found that 33.3% of the students had refractive errors myopia. In addition, there is a significant relationship between refractive errors and student achievement at SMP Negeri Padang City. Students who feel that their vision is blurry to see far away should immediately check their eyes and also have to be careful about the characteristics of myopia disorders and other refractive errors. It is recommended that students who have wrong reading habits pay more attention to their eye health so that unwanted things do not occur.

A remote cognitive behavioural therapy approach to treating hoarding disorder in an older adult

AbstractHoarding disorder (HD) is characterised by excessive acquisition and distress associated with discarding objects, resulting in significant clutter. At present, cognitive behavioural therapy (CBT) represents the strongest evidence base for treating HD, although some limitations exist. Little research has examined the effectiveness of remote-CBT interventions for HD in older adults. This case study focuses on Mary, an older female adult presenting with clinically significant hoarding behaviours which severely impact her daily functioning and quality of life. Assessment and intervention followed a structured CBT approach. Despite the complicating factor of COVID-19, Mary responded well to a remote-CBT intervention, with progress indicators suggesting modest improvements in personal, social and occupational functioning. These findings support the use of remote-CBT for HD in both reducing frequency and intensity of hoarding behaviours and improving wellbeing.Key learning aims(1)Hoarding disorder (HD) is a poorly understood disorder that can significantly impact an individual’s personal, social and occupational functioning.(2)According to a cognitive behavioural model, HD emanates from information-processing deficits, emotional attachment difficulties, behavioural avoidance and maladaptive beliefs about objects and the self (Frost and Hartl, 1996).(3)Observations from this case study suggest the acceptability and effectiveness of a remote cognitive behavioural therapy (CBT) intervention for HD, with outcomes appearing congruous with those produced by face-to-face intervention.(4)While research attests to the effectiveness of a CBT intervention for HD, an augmented account of the mechanisms through which these outcomes are achieved is required.

Аутоподобный тип адаптации, феноменология процесса развития и адаптации человека, имеющего расстройства аутистического спектра

Autism spectrum disorder (ASD) is one of the most common developmental disorders. It includes impaired socialization and communication, stereotypical behaviors, cognitive abnormalities, and a wide range of sensory features. While most experts now agree that the social impairments seen in ASD are caused by cognitive deficits, including deficits in cognitive processing of sensory information, there is yet no generally accepted theory to explain the causes of ASD and the nature of the relationship between the deficits in the sensory, cognitive, and social domains. This paper addresses the advances in understanding the sensory-cognitive traits defining an autistic perception, particularly at early age, and presents a model of autistic adaptation (AA) suggesting that social deficits, rigid behavioral patterns, and self-stimulation can be conceived as a consequence of a suboptimal adaptation strategy brought forth by a need to cope with sensory hypersensitivity and to make the outside world a less chaotic and more predictable place. As a result of this adaptation, most children with ASD at an early age (up to 1.5-2 years) form a system of protection against external sensory stimuli perceived as excessively intense at a subjective level; this protection system includes behavioral responses aimed at limiting incoming sensory information and increasing predictability of sensations received by actively searching for the more uniform and predictable external stimuli, avoiding social interaction, narrowing activity range, and following rigid behavior patterns. Special attention is paid to a well-documented tendency of children with ASD to use peripheral vision instead of central vision (lateral glances) and to refrain from behaviors aimed on integration of auditory and visual information; these sensory behaviors, though helpful in preventing sensory overflow, lead to an even more fragmented perception of an outside world characteristic for an autistic personality. Sensory self-stimulation (stimming) is also perceived as a specific adaptive mechanism that provides a child with ASD with predictable and controllable sensations and is aimed at reducing anxiety associated with the intense and unpredictable flow of external sensory information. Further attempts to better understand the specific behaviors and perceptual traits associated with autistic adaptation may lead to development of more effective intervention programs for children with ASD. A broad range of sensory integration therapies are sought that aim to establish new behavioral responses and perception strategies helping to integrate the sensory information, cope with sensory overflow, and enable us to explore the world in a more positive and efficient way.

Ошибки эпизодической вербальной памяти у больных шизофренией и в группе здоровых людей с разными профилями шизотипических черт

The aim of the study was to provide a fine grain analysis of errors generated on word list learning tasks by schizophrenia patients and healthy controls with different profiles of schizotypal traits, since it can shed light on the cognitive mechanisms of memory impairment in these cohorts. 511 patients (mean age 33.40±11.53 years; 57% women) and 307 healthy controls (mean age 25.20±7.64 years; 73% women) completed the Rey Auditory Verbal Learning Test (A. Rey, 1964). The healthy subjects were assigned to groups with low, high, positive and negative schizotypy based on the Schizotypal Personality Questionnaire adapted by A.G. Efremov and S.N. Enikolopov (2002). In patients, symptomatology was assessed with the Positive and Negative Syndrome Scale adapted by S.N. Mosolov (2001). We analyzed the number of extra-list intrusions, their perseverations, frequency and strength of the associations with stimuli, as well as phonetic intrusions, intrusions from interference trails, and false recognition of semantic and phonetic lures. The results showed that patients are characterized by an increase in the number of extra-list intrusions and their perseverations, proactive interference and recognition of semantic lures; similar trends regarding extra-list intrusions and false recognitions were observed in the high schizotypy group. The data can be interpreted in favor of the idea of impairment of reality monitoring and insufficient encoding of stimulus’s surface features as inherent deficits of information processing in schizophrenia.

Dendritic spine membrane proteome and its alterations in autistic spectrum disorder.

Dendritic spines are small protrusions stemming from the dendritic shaft that constitute the primary specialization for receiving and processing excitatory neurotransmission in brain synapses. The disruption of dendritic spine function in several neurological and neuropsychiatric diseases leads to severe information-processing deficits with impairments in neuronal connectivity and plasticity. Spine dysregulation is usually accompanied by morphological alterations to spine shape, size and/or number that may occur at early pathophysiological stages and not necessarily be reflected in clinical manifestations. Autism spectrum disorder (ASD) is one such group of diseases involving changes in neuronal connectivity and abnormal morphology of dendritic spines on postsynaptic neurons. These alterations at the subcellular level correlate with molecular changes in the spine proteome, with alterations in the copy number, topography, or in severe cases in the phenotype of the molecular components, predominantly of those proteins involved in spine recognition and adhesion, reflected in abnormally short lifetimes of the synapse and compensatory increases in synaptic connections. Since cholinergic neurotransmission participates in the regulation of cognitive function (attention, memory, learning processes, cognitive flexibility, social interactions) brain acetylcholine receptors are likely to play an important role in the dysfunctional synapses in ASD, either directly or indirectly via the modulatory functions exerted on other neurotransmitter receptor proteins and spine-resident proteins.

Clusters Across Multiple Domains of Health-Related Quality of Life Reveal Complex Patient Outcomes After Subarachnoid Hemorrhage.

Patients with subarachnoid hemorrhage were prospectively identified. Clinical data were prospectively recorded. Health-related quality of life was prospectively assessed at 3-month follow-up using the National Institutes of Health Patient Reported Outcomes Measurement Information System and neuro-quality of life in the domains of mobility, cognitive function, satisfaction with social roles, and depression. We used k-means clustering to analyze prospectively recorded health-related quality of life data, identifying clusters of complex patient outcomes. Decision tree analysis identified index hospital stay factors predictive of a patient having a particular complex patient outcome at follow-up. Academic medical center. One hundred three survivors of subarachnoid hemorrhage. None. We analyzed 103 patients, of whom 75 (72.8%) were female, and mean age was 53.6 ± 13.4 years. There were three complex patient outcomes: health-related quality of life greater than 1 sd better than the U.S. mean across all domains (n = 23, 22.3%), health-related quality of life greater than 1 sd worse than U.S. mean across all domains (n = 26, 25.2%), and satisfaction with social roles greater than 0.5 sd worse than U.S. mean with cognitive function, depression, and mobility scores near the U.S. mean (n = 54, 52.4%). In decision tree analysis, hospital disposition and Hunt and Hess Grade were associated with complex patient outcome. Complex patient outcomes across multiple domains of health-related quality of life at follow-up after subarachnoid hemorrhage are distinct and may be predictable.

Binocular Interactions in Glaucoma Patients With Nonoverlapping Visual Field Defects: Contrast Summation, Rivalry, and Phase Combination.

PurposeIn glaucoma, visual field defects in the left and right eye may be non-overlapping, resulting in an intact binocular visual field. In clinical management, these patients are often considered to have normal vision. However, visual performance also relies on binocular processing. The aim of this study was to evaluate binocular visual functions in glaucoma patients with intact binocular visual field, normal visual acuity, and stereoscopy.MethodsWe measured in 10 glaucoma patients and 12 age-similar controls: (1) monocular and binocular contrast sensitivity functions (CSF) using a modified quick CSF test to assess binocular contrast summation, (2) dominance during rivalry, and (3) contrast ratio at balance point with a binocular phase combination test. A mirror stereoscope was used to combine the left and right eye image (each 10° horizontally by 12° vertically) on a display.ResultsArea under the monocular and binocular CSF was lower in glaucoma compared to healthy (P < 0.001), but the binocular contrast summation ratio did not differ (P = 0.30). For rivalry, the percentage of time of mixed percept was 9% versus 18% (P = 0.056), the absolute difference of the percentage of time of dominance between the two eyes 19% versus 10% (P = 0.075), and the rivalry rate 8.2 versus 12.1 switches per minute (P = 0.017) for glaucoma and healthy, respectively. Median contrast ratio at balance point was 0.66 in glaucoma and 1.03 in controls (P = 0.011).ConclusionsBinocular visual information processing deficits can be found in glaucoma patients with intact binocular visual field, normal visual acuity, and stereoscopy.

Structure of Cognitive Functions in Monolingual Preschool Children With Typical Development and Children With Developmental Language Disorder.

Purpose Developmental language disorder (DLD) is defined by persistent difficulties with language, but a growing body of evidence suggests that it is also associated with domain-general and nonverbal information-processing deficits. However, the interconnections between cognitive functions, both nonverbal and language related, are still unclear. With the aim of gaining more comprehensive insight into the cognitive deficits related to DLD, we investigated and compared the cognitive structure of children with DLD and typically developing (TD) children. Method As a part of the Helsinki longitudinal SLI study, monolingual Finnish preschoolers (N = 154; TD group: n = 66, DLD group: n = 88) were assessed with 23 tasks measuring nonverbal and verbal reasoning, language processing, memory, visuomotor functions, attention, and social cognition. Exploratory factor analysis and structural equation modeling were performed to examine latent constructs and to test measurement invariance between the TD and DLD groups. Results Measurement invariance was not found across the TD and DLD groups. Best fitting structure for TD children included factors reflecting verbal abilities, processing speed/short-term memory, visuomotor functions, and visuoconstructive abilities/nonverbal reasoning. The DLD group's structure comprised nonverbal abilities, naming/expressive language, verbal comprehension, and verbal/declarative memory. Conclusions The findings suggest that the structure of cognitive functions differs in TD children and children with DLD already at preschool age. Nonverbal functions seem more unified, whereas verbal functions seem more varying in preschoolers with DLD compared to TD children. The results can be used in future research for prognosis of DLD and planning interventions.

Effects of methylphenidate on mismatch negativity and P3a amplitude of initially psychostimulant-naïve, adult ADHD patients.

Deficient information processing in ADHD theoretically results in sensory overload and may underlie the symptoms of the disorder. Mismatch negativity (MMN) and P3a amplitude reflect an individual's detection and subsequent change in attention to stimulus change in their environment. Our primary aim was to explore MMN and P3a amplitude in adult ADHD patients and to examine the effects of methylphenidate (MPH) on these measures. Forty initially psychostimulant-naïve, adult ADHD patients without comorbid ASD and 42 matched healthy controls (HC) were assessed with an MMN paradigm at baseline. Both groups were retested after 6 weeks, in which patients were treated with MPH. Neither significant group differences in MMN nor P3a amplitude were found at baseline. Although 6-week MPH treatment significantly reduced symptomatology and improved daily functioning of the patients, it did not significantly affect MMN amplitude; however, it did significantly reduce P3a amplitude compared to the HC. Furthermore, more severe ADHD symptoms were significantly associated with larger MMN amplitudes in the patients, both at baseline and follow-up. We found no evidence for early information processing deficits in patients with ADHD, as measured with MMN and P3a amplitude. Six-week treatment with MPH decreased P3a but not MMN amplitude, although more severe ADHD-symptoms were associated with larger MMN amplitudes in the patients. Given that P3a amplitude represents an important attentional process and that glutamate has been linked to both ADHD and MMN amplitude, future research should investigate augmenting MPH treatment of less responsive adults with ADHD with glutamatergic antagonists.

The viability of the frequency following response characteristics for use as biomarkers of cognitive therapeutics in schizophrenia

Deficits in early auditory information processing contribute to cognitive and psychosocial disability; this has prompted development of interventions that target low-level auditory processing, which may alleviate these disabilities. The frequency following response (FFR) is a constellation of event-related potential and frequency characteristics that reflect the processing of acoustic stimuli at the level of the brainstem and ascending portions of the auditory pathway. While FFR is a promising candidate biomarker of response to auditory-based cognitive training interventions, the psychometric properties of FFR in schizophrenia patients have not been studied. Here we assessed the psychometric reliability and magnitude of group differences across 18 different FFR parameters to determine which of these parameters demonstrate adequate internal consistency. Electroencephalography from 40 schizophrenia patients and 40 nonpsychiatric comparison subjects was recorded during rapid presentation of an auditory speech stimulus (6000 trials). Patients showed normal response amplitudes but longer latencies for most FFR peaks and lower signal-to-noise ratios (SNRs) than healthy subjects. Analysis of amplitude and latency estimates of peaks, however, indicated a need for a substantial increase in task length to obtain internal consistency estimates above 0.80. In contrast, excellent internal consistency (>0.95) was shown for FFR sustained responses. Only SNR scores reflecting the FFR sustained response yielded significant group differences and excellent internal consistency, suggesting that this measure is a viable candidate for use in clinical treatment studies. The present study highlights the use of internal consistency estimates to select FFR characteristics for use in future intervention studies interested in individual differences among patients.

Startle Habituation: A Tool for Assessing Information Processing Deficits in Zebrafish Model of Schizophrenia

Prepulse inhibition (PPI) and habituation of acoustic startle reflex have been extensively used to assess deficits in the sensorimotor functions of human patients and animal models of schizophrenia. These assays require expensive and sophisticated experimental setup for fine control of acoustic stimuli and sound attenuation. In this study, we investigate whether startle habituation assay based on mechanical (tap) stimuli can induce similar impairment in the habituation response in the schizophrenia model of larval zebrafish. For this purpose, a custom startle apparatus consisting of a 9 V push and pull solenoid and an Arduino Uno microcontroller was used to generate tap stimuli at desired intervals. Our results showed that tap stimuli at 1 Hz effectively evoked startle response in the control fishes which habituated after a few trials. The habituation response was significantly impaired in the MK801-induced schizophrenia model, similar to that elicited by acoustic startle stimuli in a previous study. We propose this simple and inexpensive method as an alternative tool for studying information processing and attention deficits in the pharmacological model of schizophrenia in zebrafish.

Performance of Patients with Relapsing-Remitting Multiple Sclerosis on the Wechsler Memory Scale-Fourth Edition (WMS-IV): Preliminary Clinical Findings

Historically, the Wechsler Memory Scales have been one of the most commonly used measures of memory in clinical neuropsychological evaluations. There are limited published reports, however, analyzing the performance of patients with multiple sclerosis (MS) on the Fourth Edition of the test. The aim of this investigation was to describe the utility of the Wechsler Memory Scale-Fourth Edition (WMS-IV) in detecting and characterizing the memory deficits associated with relapsing-remitting MS. Thirty-four outpatients with clinically definite relapsing-remitting MS were administered the WMS-IV and Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV). Means for age, education, and duration of MS diagnosis were 43.15, 14.88, and 8.41 years, respectively. Index scores did not differ significantly across the five WMS-IV domains. Comparison of actual WMS-IV indexes with those predicted by the WAIS-IV General Ability Index revealed that in every instance predicted index means were significantly higher than actual index means. Only 6 (17.6%) of 34 patients had all five actual and predicted index scores at comparable levels; whereas, 28 (82.4%) had ≥ 1 actual indexes significantly below the predicted level. Contrary to prior research using earlier versions of these measures, more patients demonstrated relatively reduced performances on the WMS-IV Visual Working Memory Index than on the WAIS-IV Processing Speed Index. Results support the use of the WMS-IV in evaluating learning and memory in individuals with MS. Findings also challenge the notion that the information processing deficits in MS are more reflective of reduced processing speed than impaired working memory.

PlexinA1 deficiency in BALB/cAJ mice leads to excessive self-grooming and reduced prepulse inhibition

PlexinA1 (PlxnA1) is a transmembrane receptor for semaphorins, a large family of proteins that act as axonal guidance cues during nervous system development. However, there are limited studies on PlxnA1 function in neurobehavior. The present study examined if PlxnA1 deficiency leads to behavioral abnormalities in BALB/cAJ mice. PlxnA1 knockout (KO) mice were generated by homologous recombination and compared to wild type (WT) littermates on a comprehensive battery of behavioral tests, including open field assessment of spontaneous ambulation, state anxiety, and grooming, home cage grooming, the wire hang test of muscle strength, motor coordination on the rotarod task, working memory on the Y maze alternation task, cued and contextual fear conditioning, anxiety on the elevated plus maze, sociability to intruders, and sensory processing as measured by prepulse inhibition (PPI). Measures of motor performance, working memory, fear memory, and sociability did not differ significantly between genotypes, while PlxnA1 KO mice displayed excessive self-grooming, impaired PPI, and slightly lower anxiety. These results suggest a crucial role for PlxnA1 in the development and function of brain regions controlling self-grooming and sensory gating. PlxnA1 KO mice may be a valuable model to investigate the repetitive behaviors and information processing deficits characteristic of many neurodevelopmental and psychiatric disorders.

Interval Timing in Pediatric Multiple Sclerosis: Impaired in the Subsecond Range but Unimpaired in the One-Second Range.

Background: For adult multiple sclerosis (MS) patients, impaired temporal processing of simultaneity/successiveness has been frequently reported although interval timing has been investigated in neither adult nor pediatric MS patients. We aim to extend previous research in two ways. First, we focus on interval timing (instead of simultaneity/successiveness) and differentiate between sensory-automatic processing of intervals in the subsecond range and cognitive processing of intervals in the one-second range. Second, we investigate whether impaired temporal information processing would also be observable in pediatric MS patients' interval timing in the subsecond and one-second ranges.Methods: Participants were 22 pediatric MS patients and 22 healthy controls, matched for age, gender, and psychometric intelligence as measured by the Culture Fair Test 20-R. They completed two auditory interval-timing tasks with stimuli in the subsecond and one-second ranges, respectively, as well as a frequency discrimination task.Results: Pediatric MS patients showed impaired interval timing in the subsecond range compared to healthy controls with a mean difference of the difference limen (DL) of 6.3 ms, 95% CI [1.7, 10.9 ms] and an effect size of Cohen's d = 0.830. The two groups did not differ significantly in interval timing in the one-second range (mean difference of the DL = 26.9 ms, 95% CI [−14.2, 67.9 ms], Cohen's d = 0.399) or in frequency discrimination (mean difference of the DL = 0.4 Hz, 95% CI [−1.1, 1.9 Hz], Cohen's d = 0.158).Conclusion: The results indicate that, in particular, the sensory-automatic processing of intervals in the subsecond range but not the cognitive processing of longer intervals is impaired in pediatric MS patients. This differential pattern of results is unlikely to be explained by general deficits of auditory information processing. A tentative explanation, to be tested in future studies, points to subcortical deficits in pediatric MS patients, which might also underlie deficits in speech and visuomotor coordination typically reported in pediatric MS patients.