1,721,043 research outputs found
Effects of strategies on mental rotation and hemispheric lateralization: neuropsychological evidence
No full textWe can predict how an object would look if we were to see it from different viewpoints by imagining its rotation. This essential human ability, called mental rotation (MR), guides individuals' actions by constantly updating their environmental consequences. It is, however, still under debate whether the way in which our brain accomplishes this operation is determined by the type of stimulus or rather by a mental strategy. Here we present neuropsychological evidence sustaining the view that what matters is the type of strategy adopted in MR. Thus, independently of the type of stimulus, patients with left hemisphere lesions showed a selective deficit in MR as a consequence of their manual activity, whereas patients with right hemisphere lesions were found impaired in MR by means of a visual strategy. We conclude that MR is achieved by recruiting different strategies, implicitly triggered or prompted at will, each sustained by a unilateral brain network
Language brain representation in bilinguals with different age of appropriation and proficiency of the second language: A meta-analysis of functional imaging studies
Full text linkLanguage representation in the bilingual brain is the result of many factors, of which age of appropriation (AoA) and proficiency of the second language (L2) are probably the most studied. Many studies indeed compare early and late bilinguals, although it is not yet clear what the role of the so-called critical period in L2 appropriation is. In this study, we carried out coordinate-based meta-analyses to address this issue and to inspect the role of proficiency in addition to that of AoA. After the preliminary inspection of the early (also very early) and late bilinguals’ language networks, we explored the specific activations associated with each language and compared them within and between the groups. Results confirmed that the L2 language brain representation was wider than that associated with L1. This was observed regardless of AoA, although differences were more relevant in the late bilinguals’ group. In particular, L2 entailed a greater enrollment of the brain areas devoted to the executive functions, and this was also observed in proficient bilinguals. The early bilinguals displayed many activation clusters as well, which also included the areas involved in cognitive control. Interestingly, these regions activated even in L1 of both early and late bilingual groups, although less consistently. Overall, these findings suggest that bilinguals in general are constantly subjected to cognitive effort to monitor and regulate the language use, although early AoA and high proficiency are likely to reduce this
Dissociation between the mental rotation of visual images and motor images in unilateral brain-damaged patients
No full textEffects of Linguistic Distance on Second Language Brain Activations in Bilinguals: An Exploratory Coordinate-Based Meta-Analysis
Full text linkIn this quantitative meta-analysis, we used the activation likelihood estimation (ALE) approach to address the effects of linguistic distance between first (L1) and second (L2) languages on language-related brain activations. In particular, we investigated how L2-related networks may change in response to linguistic distance from L1. Thus, we examined L2 brain activations in two groups of participants with English as L2 and either (i) a European language (European group, n = 13 studies) or (ii) Chinese (Chinese group, n = 18 studies) as L1. We further explored the modulatory effect of age of appropriation (AoA) and proficiency of L2. We found that, irrespective of L1-L2 distance—and to an extent—irrespective of L2 proficiency, L2 recruits brain areas supporting higher-order cognitive functions (e.g., cognitive control), although with group-specific differences (e.g., the insula region in the European group and the frontal cortex in the Chinese group). The Chinese group also selectively activated the parietal lobe, but this did not occur in the subgroup with high L2 proficiency. These preliminary results highlight the relevance of linguistic distance and call for future research to generalize findings to other language pairs and shed further light on the interaction between linguistic distance, AoA, and proficiency of L2
Causal Role of the Sensorimotor Cortex in Action Simulation: Neuropsychological Evidence
No full textInterest in sensorimotor cortex involvement in higher cognitive functions has recently been revived, although whether the cortex actually contributes to the simulation of body part movements has not yet been established. Neurosurgical patients with selective lesions to the hand sensorimotor representation offer a unique opportunity to demonstrate that the sensorimotor cortex plays a causal role in hand action simulations. Patients with damage to hand representation showed a selective deficit in simulating hand movements compared with object movements (Experiment 1). This deficit extended to objects when the patients imagined moving them with their own hands while maintaining the ability to visualize them rotating in space (Experiment 2). The data provide conclusive evidence for a causal role of the sensorimotor cortex in the continuous update of sensorimotor representations while individuals mentally simulate motor acts
Introducing the special topic The when and why of sensorimotor processes in conceptual knowledge and abstract concepts
Full text linkAttention to the other’s body sensations modulates the ventromedial prefrontal cortex
Full text linkTheory of Mind (ToM) is involved in experiencing the mental states and/or emotions of others. A further distinction can be drawn
between emotion and perception/sensation. We investigated the mechanisms engaged when participants’ attention is driven toward
specific states. Accordingly, 21 right-handed healthy individuals performed a modified ToM task in which they reflected about someone’s
emotion or someone’s body sensation, while they were in a functional magnetic resonance imaging scanner. The analysis of brain
activity evoked by this task suggests that the two conditions engage a widespread common network previously found involved in
affective ToM (temporo-parietal junction (TPJ), parietal cortex, dorso-lateral prefrontal cortex (DLPFC), medial- prefrontal cortex (MPFC),
Insula). Critically, the key brain result is that body sensation implicates selectively ventromedial prefrontal cortex (VMPFC). The current
findings suggest that only paying attention to the other’s body sensations modulates a self-related representation (VMPFC)
Brain mapping. a novel intraoperative neuropsychological approach
No full textOBJECTIVE Awake surgery and mapping are performed in patients with low-grade tumors infiltrating functional brain areas for which the greater the resection, the longer the patient survival. However, the extent of resection is subject to preservation of cognitive functions, and in the absence of proper feedback during mapping, the surgeon may be less prone to perform an extensive resection. The object of this study was to perform real-time continuous assessment of cognitive function during the resection of tumor tissue that could infiltrate eloquent tissue. METHODS The authors evaluated the use of new, complex real-time neuropsychological testing (RTNT) in a series of 92 patients. They reported normal scoring and decrements in patient performance as well as reversible intraoperative neuropsychological dysfunctions in tasks (for example, naming) associated with different cognitive abilities. RESULTS RTNT allowed one to obtain a more defined neuropsychological picture of the impact of surgery. The influence of this monitoring on surgical strategy was expressed as the mean extent of resection: 95% (range 73%-100%). At 1 week postsurgery, the neuropsychological scores were very similar to those detected with RTNT, revealing the validity of the RTNT technique as a predictive tool. At the follow-up, the majority of neuropsychological scores were still > 70%, indicating a decrease of < 30%. CONCLUSIONS RTNT enables continuous enriched intraoperative feedback, allowing the surgeon to increase the extent of resection. In sharp contrast to classic mapping techniques, RTNT allows testing of several cognitive functions for one brain area under surgery
Continuous Real-Time Neuropsychological Testing during Resection Phase in Left and Right Prefrontal Brain Tumors
No full textBackground: Executive functions are multi-component and are based on large-scale brain networks. For patients undergoing brain surgery in the prefrontal cortex, resection in the anterior prefrontal sites is assisted by continuous monitoring of their performance on several tasks measuring components of executive functions. In this study, we did not test patients during direct cortical stimulation, but during resection itself. We chose tests routinely used to assess executive functions and included them in a protocol for left (LH) and right (RH) hemisphere prefrontal resections. This protocol is meant to be used during real-time neuropsychological testing (RTNT)-an already established monitoring technique. Methods: We retrospectively reviewed a consecutive series of 29 adult patients with glioma in the superior and middle frontal areas who performed the RTNT sequence throughout the resection phase. The testing protocol comprised 10 tests for LH frontal resections and 9 tests for RH frontal resections. Results: RH patients showed a median performance on RTNT with significantly lower scores for visuo-spatial attention and emotion processing (95% Confidence Interval Lower bound of 66.55 and 82.57, respectively, chi 2 (7) = 32.8, p 0.05, n.s.; LH patients: chi 2 (5) = 3.35, p > 0.05, n.s.). Mean extent of resection was 95.33% +/- 9.72 for the RH group and 94.64% +/- 6.74 for the LH group. Patients showed good performance post- vs. pre-surgery. The greater difference in the number of LH patients scoring within the normal range was found for the symbol-digit modality test (83.3% to 62%), Stroop test (100% to 77%) and short-term memory (84.61% to 72.72%) and working memory (92.3% to 63.63%). For RH patients, the main changes were observed on the clock drawing test (100% to 77.7%) and cognitive estimation (100% to 72.7%). Conclusions: Frontal RTNT offers continuous and reliable feedback on the patients' cognitive status during resection in frontal areas
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