Cortex最新文献

A case of brain injury with a transient syndrome of mainly disinhibited behaviour (Franz Binz) was the subject of the 1888 medical dissertation of Leonore Welt (∗1859 Chernivtsi, Ukraine; †1944 Geneva, Switzerland) which came to be discussed quite controversially. Although Binz was never fully forgotten, the similar "American crow-bar case" (Phineas Gage) attracted more interest. Welt's study, in contrast, provides not only well-illustrated neuropathological findings but also more detailed clinical data. Here, the clinical report and sections of its analysis are translated from the German original. Through comparison with similar cases, Welt proposed the straight gyrus (gyrus rectus) as the main area responsible. The transient nature of the behavioural alteration was taken as indicating a peculiar disease process at that location. She stressed that disinhibited behaviour suggests fronto-orbital lesions, but that the conclusion is not to be reversed. She had noted the absence of symptoms in the majority of similarly situated injuries: normal behaviour thus being no proof of an intact fronto-orbital region. Along with two sisters, Rosa Welt-Straus (1856-1938) and Sara Welt-Kakels (1860-1943), Leonore Gourfein-Welt was among the first females from then Austria to graduate in medicine - against considerable resistance. After her thesis work, she turned to practising ophthalmology in Geneva.

Barsalou (1999) proposes that conceptual knowledge is represented by mental simulations containing perceptual information derived from actual experiences. Although a substantial number of studies have provided evidence consistent with this view in native language comprehension, it remains unclear whether the non-native language comprehension processes also include mental simulations. The current study successfully replicates the shape match effect in sentence-picture verification (Zwaan et al., 2002) for non-native English language comprehenders, indicating native-like visual simulations. In addition, participants displayed better delayed recognition memory when the shape of the depicted objects matched the shape that was implied by the sentence than when it did not, suggesting that visual simulations were generated spontaneously in naturalistic non-native language comprehension. Additional correlational analyses revealed no relationship between English proficiency and the size of the match effect.

Traditional systems consolidation theories of memory suggest that the role of the hippocampus in maintaining memory representations diminishes over time, with learned information eventually becoming fully independent of the hippocampus. Knowledge of collocations in one's native (L1) language are acquired during development and are solidly acquired by adulthood. Remote semantic knowledge of collocations might therefore be expected to be resistant to hippocampal pathology. Patients with hippocampal damage and severe anterograde amnesia completed two tasks testing English collocation knowledge originally designed for use with English language learners. Patients with hippocampal damage demonstrated impairments in recognition of common English collocations, despite a lifetime of language experience (including postsecondary education) prior to sustaining this damage. These results suggest the hippocampus contributes to the long-term maintenance of linguistic representations and provides a challenge to traditional consolidation views of memory and an extension of newer theories to include a role for the hippocampus in maintaining semantic memory.

An individual's inability to control the movements of their own hand is known as the Anarchic Hand Syndrome. The hand may perform apparently purposeful actions but acts as if it has a will of its own. Although the syndrome was first described over a century ago, the nature of the condition remains, for the most part, obscure, in particular in terms of the definition of the main symptoms and the underlying neural networks. The present study compares the results from in-depth assessments, made at repeated intervals (2, 4 and 7 months from the lesion onset) of the anarchic hand symptoms in three patients suffering from various different forms of brain damage. An investigation of direct grey matter damage and structural connectivity allowed us to compare the grey matter lesions and white matter disconnections in the three patients. A "core" characteristic relating to anarchic hand symptoms was identified, involving, in particular, both apparently purposeful movements (i.e., magnetic apraxia, grasping, bimanual incoordination, disorders in manual dexterity and action sequencing) and non-purposeful movements (i.e., levitation, synkinesis and mirror movements). Furthermore, ideomotor apraxia may also be associated with this syndrome. No overlapping areas of grey matter lesions were found in the three patients. In contrast, a pattern of common white matter disconnections was found, which involves inter-hemispheric disconnections (via corpus callosum), the long intra-hemispheric tracts (via SLF, IFOF and Arcuate) and the descendent tracts (corticospinal tract). These results are discussed in terms of awareness of motor intention.

Background: This study aimed to evaluate the capacity of neuropsychological assessment to predict the regional brain metabolism in a cohort of patients with amnestic Alzheimer's disease (AD) and behavioral variant frontotemporal dementia (bvFTD) using Machine Learning algorithms.

Methods: We included 360 subjects, consisting of 186 patients with AD, 87 with bvFTD, and 87 cognitively healthy controls. All participants underwent a neuropsychological assessment using the Addenbrooke's Cognitive Examination and the Neuronorma battery, in addition to [¹⁸F]-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging. We trained Machine Learning algorithms, including artificial neural networks (ANN) and models that incorporate genetic algorithms (GAs), to predict the presence of regional hypometabolism in FDG-PET imaging based on cognitive testing results.

Results: The proposed models demonstrated the ability to predict hypometabolism trends with approximately 70% accuracy in key regions associated with AD and bvFTD. In addition, we showed that incorporating neuropsychological tests provided relevant information for predicting brain hypometabolism. The temporal lobe was the best-predicted region, followed by the parietal, frontal, and some areas in the occipital lobe. Diagnosis played a significant role in the estimation of hypometabolism, and several neuropsychological tests were identified as the most important predictors for different brain regions. In our experiments, classical Machine Learning models, such as support vector machines enhanced by a preliminary feature selection step using GAs outperformed ANNs.

Conclusions: A successful prediction of regional brain metabolism of patients with AD and bvFTD was achieved based on the results of neuropsychological examination and Machine Learning algorithms. These findings support the neurobiological validity of neuropsychological examination and the feasibility of a topographical diagnosis in patients with neurodegenerative disorders.

The applause sign (AS) is a recognized phenomenon observed in progressive supranuclear palsy (PSP) and other neurological conditions where individuals produce over three claps following a request to clap only thrice after a demonstration. In this study, we introduced a novel linguistic phenomenon termed the oral applause sign (OAS) associated with the AS. The OAS is characterized by increased repetition counts of Japanese repetitive onomatopoeic words, such as uttering "pata-pata-pata" instead of the expected "pata-pata." We identified this phenomenon in a patient with PSP exhibiting the AS and mild apraxia of speech. In addition, we developed the three-"pata" test, instructing the patient to say "pata" only thrice after demonstration without any semantic context, and reproduced the phenomenon of the additional increase of "pata" verbalization. The core feature of OAS is an inability to limit the count when repeating a small number of syllables continuously, similar to the inability to stop clapping. The shared features between the OAS and AS suggest potential overlapping mechanisms involving the dysfunction of the frontal lobe and subcortical structures and possibly, apraxia of speech. Considering that the OAS is triggered purely by repetition and unlikely to be affected by semantic content, it might be observable in Japanese and other languages. Longitudinal studies with larger cohorts across various neurodegenerative diseases and languages may elucidate the underlying mechanisms of the OAS and confirm its specificity to PSP, thus improving the generalizability and clinical relevance of the findings.

Effective social communication depends on the integration of emotional expressions coming from the face and the voice. Although there are consistent reports on how seeing and hearing emotion expressions can be automatically integrated, direct signatures of multisensory integration in the human brain remain elusive. Here we implemented a multi-input electroencephalographic (EEG) frequency tagging paradigm to investigate neural populations integrating facial and vocal fearful expressions. High-density EEG was acquired in participants attending to dynamic fearful facial and vocal expressions tagged at different frequencies (f_vis, f_aud). Beyond EEG activity at the specific unimodal facial and vocal emotion presentation frequencies, activity at intermodulation frequencies (IM) arising at the sums and differences of the harmonics of the stimulation frequencies (mf_vis ± nf_aud) were observed, suggesting non-linear integration of the visual and auditory emotion information into a unified representation. These IM provide evidence that common neural populations integrate signal from the two sensory streams. Importantly, IMs were absent in a control condition with mismatched facial and vocal emotion expressions. Our results provide direct evidence from non-invasive recordings in humans for common neural populations that integrate fearful facial and vocal emotional expressions.

It has been demonstrated that humans exhibit an attention bias towards the lower visual field (e.g., faster target detection for targets appearing below eye level). This bias has been interpreted as reflecting the visual motor demand in near space below eye level. In this study, we examined whether this spatial bias could be affected by participants' hand position at the time of testing. Specifically, if the hand position is held at eye level at the time of target detection, whether the bias toward the lower visual field would be reduced if the bias is directly related to the motor demand at the time of testing. Using a modified spatial cueing paradigm, in Experiment 1, we found a downward bias in reaction time measures and cueing effects in a target detection task. In Experiment 2, using the same stimulus used in Experiment 1, we compared attention performance when participants' dominant (right) hand was positioned close to the right side of the visual display with the conditions where their hand was in their laps. We revealed that despite an influence on the horizontal distribution of attention (lateral peri-hand effect), the downward bias in attention remained regardless of the hand position. This revealed that lateral peri-hand manipulation is insufficient to override the attention advantage for stimuli appearing in the lower visual field.