Posterior parietal cortex

Through the application of machine learning algorithms to neuroimaging data the brain age methodology was shown to provide a useful individual-level biological age prediction and identify key brain regions responsible for the prediction. In this study, we present the methodology of constructing a rhesus macaque brain age model using a machine learning algorithm and discuss the key predictive brain regions in comparison to the human brain, to shed light on cross-species primate similarities and differences. Structural information of the brain (e...

When performing movements in rapid succession, the brain needs to coordinate ongoing execution with the preparation of an upcoming action. Here we identify the processes and brain areas involved in this ability of online preparation. Human participants (both male and female) performed pairs of single-finger presses or three-finger chords in rapid succession while 7T fMRI was recorded. In the overlap condition, they could prepare the second movement during the first response, in the non-overlap condition only after the first response was completed...

The lateral intraparietal area (LIP) plays a crucial role in target selection and attention in primates, but the laminar microcircuitry of this region is largely unknown. To address this, we used ultra-high density laminar electrophysiology with Neuropixels probes to record neural activity in the posterior parietal cortex (PPC) of two adult marmosets while they performed a simple visual target selection task. Our results reveal neural correlates of visual target selection in the marmoset, similar to those observed in macaques and humans, with distinct timing and profiles of activity across cell types and cortical layers...

The impact of action video games on reading performance has been already demonstrated in individuals with and without neurodevelopmental disorders. The combination of action video games and posterior parietal cortex neuromodulation by a transcranial random noise stimulation could enhance brain plasticity, improving attentional control and reading skills also in adults with developmental dyslexia. In a double blind randomized controlled trial, 20 young adult nonaction video game players with developmental dyslexia were trained for 15 h with action video games...

PURPOSE: To examine hemodynamic and functional connectivity alterations and their association with neurocognitive and mental health indices in patients with chronic mild traumatic brain injury (mTBI). METHODS: Resting-state functional MRI (rs-fMRI) and neuropsychological assessment of 37 patients with chronic mTBI were performed. Intrinsic connectivity contrast (ICC) and time-shift analysis (TSA) of the rs-fMRI data allowed the assessment of regional hemodynamic and functional connectivity disturbances and their coupling (or uncoupling)...

BACKGROUND: Post-stroke lateropulsion is prevalent and has been associated with varied lesion locations, but existing imaging studies are limited by small participant cohorts. Evidence to guide lateropulsion rehabilitation is also limited. Improved understanding of lesion localization associated with lateropulsion post-stroke may inform more targeted intervention approaches. OBJECTIVES: This study investigated the associations between stroke neuroimaging data and presence of lateropulsion at inpatient rehabilitation admission...

Objective: To investigate the abnormal changes of intrinsic neural time scale (INT) in male smoking addicts based on whole brain resting state functional magnetic resonance imaging (rs-fMRI). Methods: A case-control study. The clinical data and whole brain rs-fMRI data of 139 male subjects, aged (34.1±8.8) years, recruited through the online platform from January 2019 to December 2021 were retrospectively analyzed. According to the existence of smoking addiction, they were divided into smoking addiction group ( n =83) and healthy control group ( n =56)...

Many studies infer the role of neurons by asking what information can be decoded from their activity or by observing the consequences of perturbing their activity. An alternative approach is to consider information flow between neurons. We applied this approach to the parietal reach region (PRR) and the lateral intraparietal area (LIP) in posterior parietal cortex. Two complementary methods imply that across a range of reaching tasks, information flows primarily from PRR to LIP. This indicates that during a coordinated reach task, LIP has minimal influence on PRR and rules out the idea that LIP forms a general purpose spatial processing hub for action and cognition...

BACKGROUND: Unawareness is a behavioral condition characterized by a lack of self-awareness of objective memory decline. In the context of Alzheimer's Disease (AD), unawareness may develop in predementia stages and contributes to disease severity and progression. Here, we use in-vivo multi-modal neuroimaging to profile the brain phenotype of individuals presenting altered self-awareness of memory during aging. METHODS: Amyloid- and tau-PET (N = 335) and resting-state functional MRI (N = 713) imaging data of individuals from the Anti-Amyloid Treatment in Asymptomatic Alzheimer's Disease (A4)/Longitudinal Evaluation of Amyloid Risk and Neurodegeneration (LEARN) Study were used in this research...

This systematic review presented a comprehensive survey of studies that applied transcranial magnetic stimulation and transcranial electrical stimulation to parietal and nonparietal areas to examine the neural basis of symbolic arithmetic processing. All findings were compiled with regard to the three assumptions of the triple-code model (TCM) of number processing. Thirty-seven eligible manuscripts were identified for review (33 with healthy participants and 4 with patients). Their results are broadly consistent with the first assumption of the TCM that intraparietal sulcus both hold a magnitude code and engage in operations requiring numerical manipulations such as subtraction...

BACKGROUND: This study aimed to assess abnormalities in the insular cortex of individuals suffering from migraines and examine their associations with pain duration, medication usage, and clinical symptoms. METHODS: We analyzed radiological data from 38 migraine patients who had undergone 3D iso T1-weighted brain MRI at our university hospital between 2019 and 2023. Structured questionnaires were used to collect information on participants' age, migraine type, disease duration, clinical symptoms, and medication use...

Neurons that generate persistent activity in the primate dorsolateral prefrontal and posterior parietal cortex have been shown to be predictive of behavior in working memory tasks, though subtle differences between them have been observed in how information is represented. The role of different neuron types in each of these areas has not been investigated at depth. We thus compared the activity of neurons classified as narrow-spiking, putative interneurons, and broad-spiking, putative pyramidal neurons, recorded from the dorsolateral prefrontal and posterior parietal cortex of male monkeys, to analyze their role in the maintenance of working memory...

INTRODUCTION: Posterior cortical atrophy (PCA) is a neurodegenerative syndrome characterized by progressive impairment in visuospatial and perceptual function linked to atrophy of the occipito-parietal cortex. Besides the salient visual impairment, several studies have documented subtle changes in language may also be present. Sentence repetition is a highly constrained linguistic task involving multiple linguistic and cognitive processes and have been shown to be impaired in other AD spectrum disorders, with little consensus on its relevance in PCA...

Maintaining vigilance is essential for many everyday tasks, but over time, our ability to sustain it inevitably decreases, potentially entailing severe consequences. High-definition transcranial direct current stimulation (HD-tDCS) has proven to be useful for studying and improving vigilance. This study explores if/how cognitive load affects the mitigatory effects of HD-tDCS on the vigilance decrement. Participants (N = 120) completed a modified ANTI-Vea task (single or dual load) while receiving either sham or anodal HD-tDCS over the right posterior parietal cortex (rPPC)...

The brain-derived neurotrophic factor (BDNF) mediates the plasticity associated with memory processing, and compensatorily increases after acute sleep deprivation (SD). However, whether the altered spontaneous brain activity mediates the association between BDNF and working memory in SD remains unknown. Here, we aimed to probe the mediating role of the spontaneous brain activity between plasma BDNF and WM function in SD. A total of 30 healthy subjects with regular sleep were enrolled in this study. Resting-sate functional magnetic resonance imaging (fMRI) scans and the peripheral blood were collected before and after 24 h SD...

BACKGROUND: Gait disturbance is common in older adults with vascular diseases. However, how carotid atherosclerosis affects gait remains poorly understood. The objectives were to investigate the associations between carotid intima-media thickness and specific gait performances and explore the potential role of brain structure in mediating these associations. METHODS: A cross-sectional analysis of data from the Taizhou Imaging Study was conducted, including 707 individuals who underwent both gait and carotid ultrasound examinations...

UNLABELLED: Egocentric distance and real-world size are important cues for object perception and action. Nevertheless, most studies of human vision rely on two-dimensional pictorial stimuli that convey ambiguous distance and size information. Here, we use fMRI to test whether pictures are represented differently in the human brain from real, tangible objects that convey unambiguous distance and size cues. Participants directly viewed stimuli in two display formats (real objects and matched printed pictures of those objects) presented at different egocentric distances (near and far)...

Spatial trajectory planning and execution in a social context play a vital role in our daily lives. To study this process, participants completed a goal-directed task involving either observing a sequence of preferred goals and self-planning a trajectory (Self Sequencing) or observing and reproducing the entire trajectory taken by others (Other Sequencing). The results indicated that in the observation phase, witnessing entire trajectories created by others (Other Sequencing) recruited cerebellar mentalizing areas (Crus 2 and 1) and cortical mentalizing areas in the precuneus, ventral and dorsal medial prefrontal cortex and temporo-parietal junction more than merely observing several goals (Self Sequencing)...

Alcohol use disorder is associated with overvaluation of alcohol relative to other rewards, in part due to dynamic increases in value in response to alcohol-related cues. In a neuroeconomic framework, alcohol cues increase behavioral economic demand for alcohol, but the neural correlates these cue effects are unknown. This functional magnetic resonance imaging study combined a neuroeconomic alcohol purchase task with an alcohol cue exposure in 72 heavy drinkers with established sensitivity to alcohol cues (51 % female; mean age=33...

The posterior parietal cortex (PPC) integrates multisensory and motor-related information for generating and updating body representations and movement plans. We used retrograde transneuronal transfer of rabies virus combined with a conventional tracer in macaque monkeys to identify direct and disynaptic pathways to the arm-related rostral medial intraparietal area (MIP), the ventral lateral intraparietal area (LIPv), belonging to the parietal eye field, and the pursuit-related lateral subdivision of the medial superior temporal area (MSTl)...