Visuospatial Planning Research Articles

Methylphenidate Ameliorates Behavioural and Neurobiological Deficits in Executive Function for Patients with Chronic Traumatic Brain Injury

(1) Background: Traumatic brain injury (TBI) often results in cognitive impairments, including in visuospatial planning and executive function. Methylphenidate (MPh) demonstrates potential improvements in several cognitive domains in patients with TBI. The Tower of London (TOL) is a visuospatial planning task used to assess executive function. (2) Methods: Volunteers with a history of TBI (n = 16) participated in a randomised, double-blinded, placebo-controlled, fMRI study to investigate the neurobiological correlates of visuospatial planning and executive function, on and off MPh. (3) Results: Healthy controls (HCs) (n = 18) and patients on placebo (TBI-placebo) differed significantly in reaction time (p < 0.0005) and accuracy (p < 0.0001) when considering all task loads, but especially for high cognitive loads for reaction time (p < 0.001) and accuracy (p < 0.005). Across all task loads, TBI-MPh were more accurate than TBI-placebo (p < 0.05) but remained less accurate than HCs (p < 0.005). TBI-placebo substantially improved in accuracy with MPh administration (TBI-MPh) to a level statistically comparable to HCs at low (p = 0.443) and high (p = 0.175) cognitive loads. Further, individual patients that performed slower on placebo at low cognitive loads were faster with MPh (p < 0.05), while individual patients that performed less accurately on placebo were more accurate with MPh at both high and low cognitive loads (p < 0.005). TBI-placebo showed reduced activity in the bilateral inferior frontal gyri (IFG) and insulae versus HCs. MPh normalised these regional differences. MPh enhanced within-network connectivity (between parietal, striatal, insula, and cerebellar regions) and enhanced beyond-network connectivity (between parietal, thalamic, and cerebellar regions). Finally, individual changes in cerebellar-thalamic (p < 0.005) and cerebellar-parietal (p < 0.05) connectivity with MPh related to individual changes in accuracy with MPh. (4) Conclusions: This work highlights behavioural and neurofunctional differences between HCs and patients with chronic TBI, and that adverse differences may benefit from MPh treatment.

How the Spreading and Intensity of Interictal Epileptic Activity Are Associated with Visuo-Spatial Skills in Children with Self-Limited Focal Epilepsy with Centro-Temporal Spikes.

This paper investigates brain-behaviour associations between interictal epileptic discharges and cognitive performance in a population of children with self-limited focal epilepsy with centro-temporal spikes (SeLECTS). Sixteen patients with SeLECTS underwent an extensive neuropsychological assessment, including verbal short-term and episodic memory, non-verbal short-term memory, attentional abilities and executive function. Two quantitative EEG indices were analysed, i.e., the Spike Wave Index (SWI) and the Spike Wave Frequency (SWF), and one qualitative EEG index, i.e., the EEG score, was used to evaluate the spreading of focal SW to other parts of the brain. We investigated associations between EEG indices and neuropsychological performance with non-parametric Spearman correlation analyses, including correction for multiple comparisons. The results showed a significant negative correlation between (i) the awake EEG score and the Block Tapping Test, a visuo-spatial short-term memory task, and (ii) the sleep SWI and the Tower of London, a visuo-spatial planning task (pcorr < 0.05). These findings suggest that, in addition to the usual quantitative EEG indices, the EEG analysis should include the qualitative EEG score evaluating the spreading of focal SW to other parts of the brain and that neuropsychological assessment should include visuo-spatial skills.

A Visuospatial Planning Task Coupled with Eye-Tracker and Electroencephalogram Systems.

The planning process, characterized by the capability to formulate an organized plan to reach a goal, is essential for human goal-directed behavior. Since planning is compromised in several neuropsychiatric disorders, the implementation of proper clinical and experimental tests to examine planning is critical. Due to the nature of the deployment of planning, in which several cognitive domains participate, the assessment of planning and the design of behavioral paradigms coupled with neuroimaging methods are current challenges in cognitive neuroscience. A planning task was evaluated in combination with an electroencephalogram (EEG) system and eye movement recordings in 27 healthy adult participants. Planning can be separated into two stages: a mental planning stage in which a sequence of steps is internally represented and an execution stage in which motor action is used to achieve a previously planned goal. Our protocol included a planning task and a control task. The planning task involved solving 36 maze trials, each representing a zoo map. The task had four periods: i) planning, where the subjects were instructed to plan a path to visit the locations of four animals according to a set of rules; ii) maintenance, where the subjects had to retain the planned path in their working memory; iii) execution, where the subjects used eye movements to trace the previously planned path as indicated by the eye-tracker system; and iv) response, where the subjects reported the order of the visited animals. The control task had a similar structure, but the cognitive planning component was removed by modifying the task goal. The spatial and temporal patterns of the EEG revealed that planning induces a gradual and lasting rise in frontal-midline theta activity (FMθ) over time. The source of this activity was identified within the prefrontal cortex by source analyses. Our results suggested that the experimental paradigm combining EEG and eye-tracker systems was optimal for evaluating cognitive planning.

Long-term effects of Cushing’s Disease on visuospatial planning and executive functioning

IntroductionPatients with remitted Cushing’s Disease (CD) often present persisting impairments in executive and cognitive functioning domains. Little research has been conducted regarding the functional neural correlates of an important executive functioning skill, namely the ability to plan, in these patients.ObjectivesTo examine visuospatial planning related brain activity in remitted CD patients and matched controls using functional magnetic resonance imaging (fMRI).MethodsfMRI scans were made using a 3-Telsa scanner while remitted CD patients (n=21) and age-, gender-, and education matched healthy controls (HCs; n=21) completed a parametric Tower of London (ToL) task. Psychological and cognitive functioning were assessed using validated questionnaires. Clinical severity was assessed retrospectively using the Cushing’s syndrome Severity Index (CSI).ResultsCD Patients were on average 45.1 (SD=7.1) years old, 81% female, and in remission for mean 10.68 (SD=7.69) years. No differences were found in number of correct trials, response times per ToL trial, or in the region of interest analyses. Exploratory wholebrain analyses found that CD patients showed more activation in several brain regions associated with higher cognitive processes on 2-, 3-, and 5-step trials compared to HCs. Over-recruitment of the right parietal operculum cortex in the patients was significantly negatively associated with the prior active disease state on the CSI (r=-0.519, p=0.02).ConclusionsThe increased brain activation during the ToL in remitted CD patients versus controls signals over-recruitment of certain brain areas involved in higher cognitive processes. CD may thus result in long-lasting, subtle scarring effects during demanding executive functioning tasks, despite remission.DisclosureNo significant relationships.

Gaze behaviour: A window into distinct cognitive processes revealed by the Tower of London test

The analysis of gaze behaviour during complex tasks provides a promising non-invasive method to examine how specific eye movement patterns relate to various aspects of cognition and action. Notably, the association between aspects of gaze behaviour and subsequent goal-directed action during high-level visuospatial problem solving remains elusive. Therefore, the current study comprehensively examined gaze behaviour using traditional and entropy-based gaze analyses in healthy adults (N = 27) while they performed the Freiburg version of the Tower of London task. Results demonstrated that both gaze analyses provided crucial temporal and spatial information related to planning, solution elaboration and execution. Specifically, gaze biases toward task-relevant areas (i.e., the work space) and an increase in gaze complexity (i.e., gaze transition entropy) during optimal performance reflected changes in cognitive demands as task difficulty increased. A comparison between optimal and non-optimal performance revealed sub-optimal gaze patterns that occurred in the early stages of planning, which were taken to reflect poor information extraction from the task environment and impaired maintenance of information in visuospatial working memory. Gaze behaviour during movement execution indicated an increased need to extract and process information from the goal space. Consequently, movement execution time increased in order to reverse erroneous movements and re-sequence the problem solution. Taken together, the traditional and entropy-based gaze analyses applied in the present study provide a promising approach to identify eye movement patterns that support neurocognitive performance on tasks relying on visuospatial planning and problem solving.

Presurgical cognitive status in patients with low-grade glioma and epilepsy: Testing the effects of seizures, antiseizure medications, and tumor localization.

BackgroundLow‐grade gliomas (LGGs) are frequently associated with epilepsy. There are few studies addressing the impact of seizures, antiseizure medications (ASMs), and lesion localization on presurgery cognitive functioning.MethodsWe tested the relation between the above‐mentioned variables in a continuous series of 73 young patients (mean age 38.3 years ± 11.7) affected by LGGs and epilepsy. The anatomical areas, involved in this sample, were the left insula with surrounding cortical and subcortical areas, the right precentral gyrus/rolandic operculum, and the white matter and cortical regions beneath.ResultsPatients’ presurgery cognitive status was within the normal range, with borderline performance for some tasks. We tested whether lower scores were related with lesion or with epilepsy‐related factors. Multiple regression identified variables that predict test scores. The Token test score was predicted by a model (p = .0078) containing the DT2T1 MRI, corrected for seizure features. Object naming performance was predicted by a model (p = .0113) containing the localization, the DT2T1 MRI, corrected for sex, EEG, and onset. Verbal fluency score was predicted by a model (p = .0056) containing the localization and the DT2T1 MRI, corrected for AEDs and EEG. Working memory score was predicted by a model (p = .0117) containing Engel class, the DT2T1 MRI, corrected for sex. Clock drawing score was predicted by a model (p < .0001) containing the Engel class, AEDs, and EEG. TMT A score was predicted by a model (p = .0022) containing localization, corrected for EEG. TMT B‐A score was predicted by a model (p = .0373) containing localization. Voxel Lesion Symptom Mapping analyses carried out on patients’ lesion volumes confirmed that patients’ level of performance correlated with lesion‐related variables.ConclusionThis preliminary study indicates that the presurgical level of performance for language tasks and for cognitive flexibility and shifting is mainly predicted by lesion‐related variables, working memory by both lesion and epilepsy‐related variables. Epilepsy clinical and instrumental characteristics predicted performance for visuospatial planning.

Planning in amnestic mild cognitive impairment: an fMRI study.

The memory impairment that is characteristic of amnestic mild cognitive impairment (aMCI) is often accompanied by difficulties in executive functioning, including planning. Though planning deficits in aMCI are well documented, their neural correlates are largely unknown, and have not yet been investigated with functional magnetic resonance imaging (fMRI). The aim of this study was to: (1) identify differences in brain activity and connectivity during planning between people with aMCI and cognitively healthy older adults, and (2) find whether planning-related activity and connectivity are associated with cognitive performance and symptoms of apathy. Twenty-five people with aMCI and 15 cognitively healthy older adults performed a visuospatial planning task (Tower of London; ToL) during fMRI. Task-related brain activation, spatial maps of task-related independent components, and seed-to-voxel functional connectivity were compared between the two groups and regressed against measures of executive functions (Trail Making Test difference score, TMT B-A; Digit Symbol Substitution Test, DSST), delayed recall (Rey Auditory Verbal Learning Test), and apathy (Apathy Evaluation Scale). People with aMCI scored lower on task-switching (TMT B-A), working memory (DSST), and planning (ToL). During planning, people with aMCI had less activation in the bilateral anterior calcarine sulcus/cuneus, the bilateral temporal cortices, the left precentral gyrus, the thalamus, and the right cerebellum. Across all participants, higher planning-related activity in the supplementary motor area, the retrosplenial cortex and surrounding areas, and the right temporal cortex was related to better delayed recall. There were no between-group differences in functional connectivity, nor were there any associations between connectivity and cognition. We also did not find any associations between brain activity or connectivity and apathy. Impaired planning in people with aMCI appears to be accompanied by lower activation in a diffuse cortico-thalamic network. Across all participants, higher planning-related activity in parieto-occipital, temporal, and frontal areas was related to better memory performance. The results point to the relevance of planning deficits for understanding aMCI and extend its clinical and neurobiological signature.

Neural correlates of executive functions in people with amnestic mild cognitive impairment

AbstractBackgroundPeople with amnestic mild cognitive impairment (aMCI) often experience difficulties in cognitive domains other than memory, including executive functioning. Though these deficits are well documented, their neural correlates remain unknown. The aim of this study was to: (1) identify differences in brain activity and connectivity during planning in people with aMCI and cognitively healthy older adults, and (2) find whether planning‐related activity and connectivity are associated with cognitive performance.MethodTwenty‐five people with aMCI (67.6 ± 5.2 y, 6 F, 3 left‐handed) and 15 cognitively healthy older adults (66.4 ± 4.3 y, 5 F, all right‐handed) performed a visuospatial planning task (Tower of London; ToL) during functional magnetic resonance imaging (fMRI). Task‐related brain activation and connectivity were compared between the two groups and regressed against measures of executive functions (Digit Symbol Substitution Test, DSST; Trail Making Test difference score, TMT B‐A) and delayed recall (Rey Auditory Verbal Learning). All fMRI analyses were controlled for scores on the Geriatric Depression Scale, the Apathy Evaluation Scale, the DSST, and the TMT B‐A, and corrected for multiple comparisons at cluster‐level.ResultAs expected, people with aMCI had significantly poorer delayed recall than cognitively healthy older adults (F = 15.8, p &lt; 0.0001). They also scored worse on the DSST (F = 5.5, p = 0.025) and the TMT B‐A (U = 77.5, p = 0.012), and were less accurate on the ToL task (F = 10.7, p = 0.002).During planning, people with aMCI had less activation in two clusters, both located in the precentral gyrus (p = 0.013 and p = 0.047). Across all participants, better performance on the DSST was associated with stronger anti‐correlation between a seed in the left middle frontal gyrus and a cluster in bilateral frontal poles (p = 0.012).ConclusionImpaired planning in people with aMCI appears to be underpinned by less activation in areas associated with sequence planning and visuospatial attention. Interestingly, more negative connectivity between the left middle frontal gyrus and frontal areas involved in working memory and task flexibility was associated with better performance on a task of executive functions.

Impaired meaning-based cognitive skills are specifically associated with poorer subjective quality of life in schizophrenia

Cognitive impairment is characteristic of schizophrenia but the nature and severity often differ between patients and the relationship with subjective quality of life (sQOL) is inconsistent. This study sought to better characterise the cognition-sQOL relationship in schizophrenia by 1) examining associations between factor analysis-derived cognitive domains and sQOL, 2) investigating if these domains independently predicted sQOL, and 3) exploring if clinical, demographic and functional variables moderated any significant relationships. 47 schizophrenia/schizoaffective disorder patients and 48 healthy controls were assessed. QOL was measured using the Lehman’s QOL Interview. Composite scores were created to represent objective QOL and sQOL, and factor analysis was used to determine cognitive domains from 14 cognitive tasks. Three cognitive domains were derived: visuospatial planning, verbal linguistic and inhibition switching. Tasks comprising the verbal linguistic cognitive domain were significantly associated with and predicted sQOL. Moderation analyses revealed that the direction of this relationship differed between patients and healthy controls, and may be moderated by positive symptom severity in patients. In conclusion, meaning-based (e.g. verbal-linguistic) cognitive abilities may be most closely related to sQOL in schizophrenia. Symptomatology may also impact this relationship, with worsening sQOL among those with more intact verbal-linguistic processing and persistent positive symptoms. These patients may therefore be at greater risk for poor sQOL, but may be more motivated and capable of engaging in and benefiting from offered psychosocial interventions.

Neural correlates of visuospatial dysfunction in Parkinson's Disease: A multimodal biomarker study

Background: In Parkinson's Disease (PD), abnormal visuospatial planning, which may affect the exploration of space, and impairments in visuospatial processing may result in systematic perceptual biases hampering motor function.

S237. MODERATORS AND RELATIONSHIPS OF COGNITION AND SUBJECTIVE QUALITY OF LIFE IN SCHIZOPHRENIA

BackgroundThe relationship between cognitive impairments and subjective quality of life (sQOL) in schizophrenia remains indeterminate, relative to studies of objective QOL (oQOL), despite much previous work. This study sought to better characterise the cognition-sQOL relationship in schizophrenia by 1) examining associations between factor analysis-derived cognitive domains and sQOL, 2) investigating if these domains predicted sQOL over other demographic and clinical variables, and 3) exploring if clinical, demographic and functional variables moderated the significant relationships.Methods47 schizophrenia/schizoaffective disorder patients (age: M=43.72, SD=11.35) and 48 healthy controls (age: M=39.82, SD=13.89) were assessed. QOL was measured using the Lehman’s QOL Interview. Composite scores were created to represent oQOL and sQOL, and factor analysis (principal axis factoring with varimax rotation) assessed for latent domains within 14 cognitive tasks. Symptomatology was assessed using the PANSS and MADRS. Pearson’s correlations and a stepwise linear regression were conducted to examine the associations between cognition and sQOL before the moderation analyses.ResultsThree cognitive domains were derived: visuospatial planning, verbal linguistic and inhibition switching. Only tasks comprising the verbal linguistic cognitive domain were significantly associated with, and predicted, sQOL (p<.05). Moderation analyses revealed that the direction of this relationship differed between patients and healthy controls (p<.05), and was moderated in patients only by positive symptom severity (p<.05).DiscussionThe relationship between cognition and sQOL in schizophrenia is determined by, and more associated with, meaning-based cognitions. It is affected by symptomatology, notably positive symptoms, which lead to worsening sQOL among those with more intact verbal linguistic processing.

Travel Planning Ability in Right Brain-Damaged Patients: Two Case Reports.

Planning ability is fundamental for goal-directed spatial navigation. Preliminary findings from patients and healthy individuals suggest that travel planning (TP)—namely, navigational planning—can be considered a distinct process from visuospatial planning (VP) ability. To shed light on this distinction, two right brain-damaged patients without hemineglect were compared with a control group on two tasks aimed at testing VP (i.e., Tower of London-16, ToL-16) and TP (i.e., Minefield Task, MFT). The former requires planning the moves to reach the right configuration of three colored beads on three pegs, whereas the latter was opportunely developed to assess TP in the navigational environment when obstacles are present. Specifically, the MFT requires participants to plan a route on a large carpet avoiding some hidden obstacles previously observed. Patient 1 showed lesions encompassing the temporoparietal region and the insula; she performed poorer than the control group on the ToL-16 but showed no deficit on the MFT. Conversely, Patient 2 showed lesions mainly located in the occipitoparietal network of spatial navigation; she performed worse than the control group on the MFT but not on the ToL-16. In both cases performances satisfied the criteria for a classical dissociation, meeting criteria for a double dissociation. These results support the idea that TP is a distinct ability and that it is dissociated from VP skills.

Junior-Real Time neuropsychological testing (j-RTNT) for a young patient undergoing awake craniotomy

We developed a junior-real-time neuropsychological testing (j-RTNT) and used it during surgery of a right fronto-insular dysembryoplastic neuroepithelial tumor causing seizures in a 16 years old female. The j-RTNT included tasks from the battery NEPSY-II.Pre-surgery evaluation detected a below average performance in visuo-spatial planning, inhibition, visual attention, planning and borderline performance in speeded naming.The j-RTNT allows detecting sudden decreases that could be caused by resection. During surgery, ECoG was characterized by slow sharp activity and spikes on the electrodes exploring the right fronto-polar region. After the resection, spikes were not detected anymore.Immediate post-surgery performance resulted within the normal range, remained below average in visuo-spatial planning, and improved in inhibition, switching and in speeded naming.Follow-up revealed cognitive recovery. Neurological assessment was unremarkable and the patient was seizure free. No epileptic activity could be observed on follow-up EEG.fMRI data showed that in the follow-up vs. pre-surgery there was a higher recruitment of the right superior frontal gyrus, a region involved in the cognitive execution and cognitive control networks.The j-RTNT is feasible with young patients, goes beyond the testing of limited functions, assessing multiple times during resection several different functions to better monitoring the effects of resection.

Meningioma can lead to pre-operative cognitive alterations even if localized in sensorimotor areas: A multimodal MRI-neuropsychological study in a series of 46 patients

Brain tumors are generally associated with cognitive changes. Little is known about cognition in patients with meningioma – a lesion that usually shifts and compresses the brain parenchyma with a low probability of infiltrate it. We investigated the cognitive functioning in a consecutive series of 46 patients with a meningioma in the sensorimotor area in the left (LH, N = 27) or in the right (RH, N = 19) hemisphere.All the patients underwent a pre-operative neuropsychological assessment and structural MRI.Clinical symptoms varied between LH and RH meningioma patients. Impaired performance was seen in naming (19.23% noun and 35% verb naming), short-term (18.18%) and working (14.24%) memory in the LH group, and in visuo-spatial tasks (25% neglect, 21.42% visuospatial planning) in the RH group.Both groups were impaired on a sensorimotor mental imagery task (LH, 66.66% of the LH 70% of the RH meningioma patients), while only the RH meningioma group was impaired on the visuo-spatial mental imagery task. The lesion MRI maximum overlap occurred in the postcentral and paracentral lobules. Edema was maximally localized on the left superior longitudinal fasciculus and the superior part of the right superior corona radiata. We found that only the meningioma mass, and not the edema, is a predictive variable in determining patients’ performance.Patients with meningioma could present with cognitive alterations at pre-surgical evaluation even if the meningioma occurs in sensorimotor areas. In the present series, a large meningioma vs. a large edema is more relevant for cognitive performance.

Differential involvement of left and right frontoparietal areas in visuospatial planning: An rTMS study

The planning process consists of pre-determining an ordered series of actions to accomplish a goal. Previous research showed that the left prefrontal cortex (PFC) is likely to create the strategy for a plan, while the right PFC could be relevant for its update. These roles for the two PFCs need to be ascertained for visuospatial planning, whether communalities or differences exist with other planning tasks. Moreover, the contribution of the posterior parietal cortex (PPC) to planning still lacks evidence. Online repetitive transcranial magnetic stimulation (1 Hz) was used, and 32 participants were involved in the visuospatial planning task in a within-subject design to inhibit either the frontal or the parietal cortex of either the left or the right hemisphere. The goal consisted of evaluating the contribution of these cortical regions, also controlling for gender, in a computerized version of the travelling salesman problem (TSP), the “Maps” task. The results showed that all the stimulated sites produced significant differences in their involvement, reflected in several parameters (such as initial planning and execution times, strategies and heuristics used), with respect to the control group. The roles for the two PFCs were generally confirmed in all measures except path length, while the contribution of the PPC emerged throughout the measures related to the ongoing execution. We concluded that the results obtained with the TSP paradigm were consistent with results obtained using other tasks used to study the planning process (such as the Tower of London) for the evaluation of PFC contribution. In addition, we showed that the contribution of the PPC to the planning process has probably been underestimated.

Intact Visuospatial Cognition in Amblyopia: Results From the Gutenberg Health Study.

To determine whether amblyopia interferes with cognitive functions requiring visuospatial processing, measured by the Tower of London (ToL) test. The current study was based on a sub-cohort from the population-based Gutenberg Health Study and included 1,569 participants aged 35 to 44 years. Amblyopia was defined as a visual acuity of 0.63 or worse (worse eye) in the presence of an amblyogenic factor; prevalence was 5%. There were three groups: participants with amblyopia (n = 78), participants with a visual acuity of 0.63 or worse (worse eye) without amblyopia (n = 65), and participants with a visual acuity of better than 0.63 (worse eye) (n = 1,426). Visuospatial planning ability was measured by the ToL test (touch-screen version), and the performance score ranged from 0 to 24, depending on the number of correctly solved problems. The authors used linear regression models to investigate the association between amblyopia and ToL test scores, adjusting for age, sex, and socioeconomic status. The mean ± standard deviation of ToL test performance was 15.31 ± 3.29 in participants with a visual acuity of better than 0.63, 14.56 ± 3.76 in the amblyopic group, and 15.14 ± 3.65 in participants with a visual acuity of 0.63 or worse without amblyopia. In a linear regression model, sex, and socioeconomic status significantly predicted planning performance (P <.0001), whereas amblyopic status did not (P = .20). Amblyopia may affect visuospatial perception, but no such relationships could be found for higher cognitive functions that strongly depend on visuospatial processing. Thus, in adulthood, individuals with amblyopia are unaffected in their visuospatial cognitive abilities, as required by the ToL test. [J Pediatr Ophthalmol Strabismus. 2019;56(6):397-401.].

The Relationship Between Language and Planning in Children With Language Impairment.

Purpose This study examined the relationship between language and planning, a higher order executive function skill, in children with specific language impairment (SLI) and typically developing (TD) children. We hypothesized differences between groups in planning performance and in the role of verbal mediation during planning. Method Thirty-one children with SLI and 50 TD age-matched peers (8-12 years) participated in the study. We assessed language ability via a standardized language measure and planning via a dual-task Tower of London paradigm with 3 conditions: no secondary task (baseline), articulatory suppression secondary task (disrupted verbal mediation), and motor suppression secondary task (control for secondary task demand). Results We found similar overall accuracy between children with SLI and TD peers on the Tower of London. Children with SLI executed trials more slowly at baseline than TD peers but not under articulatory suppression, and children with SLI spent less time planning than TD children at baseline and under articulatory suppression. There was a significant interaction among group, language ability, and planning time under articulatory suppression. Children with SLI who had relatively better language ability spent less time planning than children with SLI who had poorer language ability when verbal mediation was disrupted. This pattern was reversed for TD children. Conclusions This study provides evidence for a relationship between language and planning, yet this relationship differed between children with SLI compared to TD peers. Findings suggest that children with SLI use nonlinguistic perceptual strategies to a greater degree than verbal strategies on visuospatial planning tasks and that intervention might address strategy use for planning.

Cognitive variability in bipolar I disorder: A cluster-analytic approach informed by resting-state data

BackgroundWhile the presence of cognitive performance deficits in bipolar disorder I (BD-I) is well established, there is no consensus about which cognitive abilities are affected. Heterogeneous phenotypes displayed in BD-I further suggest the existence of subgroups among the disorder. The present study sought to identify different cognitive profiles among BD-I patients as well as potentially underlying neuronal network changes. Methods54 euthymic BD-I patients underwent cognitive testing and resting state neuroimaging. Hierarchical cluster-analysis was performed on executive function scores of bipolar patients. The derived clusters were compared against 54 age-, gender- and IQ-matched healthy controls (HC) to facilitate the interpretation of results. Further, resting state network properties were compared to identify differences probably underlying cognitive profiles. ResultsA three-cluster solution emerged. Cluster 1 (n = 22) was characterized by deficits in cognitive flexibility and motor inhibition, cluster 2 (n = 12) displayed impulsive decision-making, while cluster 3 (n = 20) showed good visuospatial planning. Weaker connections in cluster 1 compared to cluster 2 were found between regions activated during tasks cluster 1 showed deficits on. Cluster 3 had a higher modularity than cluster 2, which correlated positively with problem solving performance and risk-taking in this cluster. ConclusionObtained clusters showed distinct cognitive profiles, characterized by deficits and strengths, most of which remained precluded in a general comparison. Weaker interregional connections and separated subnetworks might underly behavioral deficits and strengths, respectively. The findings help explain the phenotypic heterogeneity observed in BD-I.This article is part of the Special Issue entitled ‘Current status of the neurobiology of aggression and impulsivity’.

Neurocognitive and behavioural performance of healthy volunteers receiving an increasing analgesic-range infusion of ketamine.

The acute and delayed effect of analgesic-range doses of ketamine on neurocognitive and behavioural outcomes is understudied. Using a non-controlled open-labelled design, three (1-h duration) increasing intravenous (IV) ketamine infusions comprising (i) 30mg bolus of ketamine + 8mg/h IV infusion, (ii) 12mg/h IV infusion and (iii) 20mg/h infusion were administered to 20 participants (15 male, 5 female, mean age = 30.8years). Whole-blood ketamine and norketamine concentrations were determined at each treatment step and post-infusion. The Cambridge Neuropsychological Test Automated Battery (CANTAB) was used to assess reaction/movement time (RTI, Simple and 5-Choice), visuospatial working memory (SWM), spatial planning (SOC) and subjective effects (visual analogue scale; VAS) during treatment and at post-treatment. Significant main effects were reported for time (dose) on CANTAB RTI 5-Choice reaction (F(4,18) = 3.41, p = 0.029) and movement time (F(4,18) = 4.42, p = 0.011), SWM (F(4,18) = 4.19, p =0.014) and SOC (F(4,18) = 4.13, p = 0.015), but not RTI Simple reaction or movement time. Post hoc analyses revealed dose-dependent effects for both RTI 5-Choice reaction and movement time (all p < 0.05). Post-treatment performance on all neurocognitive and behavioural tasks returned to baseline levels. Regression analyses revealed a weak positive linear association between SWM 'strategy' score (R2 = 0.103, p < 0.001), all performance-based CANTAB VAS items (R2 range 0.005-0.137, all p < 0.05) and ketamine blood concentrations. The open-label, non-controlled trial design somewhat precludes the ability to adequately account for random treatment effects. Notwithstanding, these results suggest that analgesic doses of ketamine produce acute, selective, dose-dependent deficits in higher-order neurocognitive and behavioural domains.

Default Mode Network Engagement Beyond Self-Referential Internal Mentation.

The default mode network (DMN) is typically associated with off-task internal mentation, or with goal-oriented tasks that require self-referential processing such as autobiographical planning. However, recent reports suggest a broader involvement of the DMN in higher cognition. In line with this view, we report global connectivity changes that are centered on the main DMN hubs of precuneus and posterior cingulate cortex during a functional magnetic resonance imaging-based visuospatial version of the Tower of London planning task. Importantly, functional connectivity of these regions with the left caudate shows a significant relationship with faster reaction time to correct responses only during the high-demand planning condition, thus offering further evidence for the DMN's engagement during visuospatial planning. The results of this study not only provide robust evidence against the widely held notion of DMN disengagement during goal-oriented, attention-demanding, externally directed tasks but also support its involvement in a broader cognitive context with a memory-related role that extends beyond self-referential, internally directed mentation.