scholarly journals Distinct cerebellar regions for body motion discrimination

2019 ◽  
Author(s):  
Chiara Ferrari ◽  
Andrea Ciricugno ◽  
Lorella Battelli ◽  
Emily D Grossman ◽  
Zaira Cattaneo
Keyword(s):  
Visual Processing ◽  
Biological Motion ◽  
Stimulus Onset ◽  
Control Site ◽  
Body Motion ◽  
Cerebellar Hemisphere ◽  
Motion Discrimination ◽  
Adaptive Social Behavior ◽  
Left Cerebellar Hemisphere ◽  
Crus I

Abstract Visual processing of human movements is critical for adaptive social behavior. Cerebellar activations have been observed during biological motion discrimination in prior neuroimaging studies, and cerebellar lesions may be detrimental for this task. However, whether the cerebellum plays a causal role in biological motion discrimination has never been tested. Here, we addressed this issue in three different experiments by interfering with the posterior cerebellar lobe using transcranial magnetic stimulation (TMS) during a biological discrimination task. In Experiments 1 and 2, we found that TMS delivered at onset of the visual stimuli over the vermis (vermal lobule VI), but not over the left cerebellar hemisphere (left lobule VI/Crus I), interfered with participants’ ability to distinguish biological from scrambled motion compared to stimulation of a control site (vertex). Interestingly, when stimulation was delivered at a later time point (300 ms after stimulus onset), participants performed worse when TMS was delivered over the left cerebellar hemisphere compared to the vermis and the vertex (Experiment 3). Our data show that the posterior cerebellum is causally involved in biological motion discrimination and suggest that different sectors of the posterior cerebellar lobe may contribute to the task at different time points.

Spontaneous Catheter Separation from the Implanted Venous Port and Its Migration to the Venous Heart: Clinical Case

2018 ◽  
Vol 5 (2) ◽  
pp. 127-132 ◽  
Author(s):  
Lyudmila V. Olkhova ◽  
Vladimir E. Popov
Keyword(s):  
Clinical Case ◽  
Care Delivery ◽  
Venous Access ◽  
Cerebellar Hemisphere ◽  
Clinical State ◽  
Venous Port ◽  
Silicone Catheter ◽  
Oncological Diseases ◽  
Left Cerebellar Hemisphere ◽  
Port Systems

Background. Currently, vascular access is one of the most important aspects in specific and accompanying treatment of cancer patients regardless of their age and sex. Partially implanted venous catheters previously described by Hickman were widely applied all over the world. The introduction of completely implanted venous port-systems revolutionized health care delivery and improved the quality of life in patients with oncological diseases. A fully implanted venous port consists of a silicone catheter which distal tip is connected to a port tank implanted subcutaneously. Such a design allows providing safe and multiple adequate vascular accesses regardless of the patient’s clinical state.Case Report. We present a clinical case of a 10-year-old patient diagnosed with medulloblastoma of the cerebellopontine angle and the left cerebellar hemisphere. The case described spontaneous detachment of an implanted venous port catheter and its migration to the venous heart in a patient who underwent chemotherapy by venous access provided through implantation of the venous port.Conclusion. Our clinical case demonstrated a rare and potentially extremely dangerous noninfectious complication associated with the use of venous port-systems. Implanted systems require washing 1–2 times per month with heparinized solutions or solutions containing taurolidine when they are not used. Periodic chest radiographs can reveal integrity alterations of the system. Any implanted system should be removed when it is not used, or it should be monitored on a regular basis.

scholarly journals The Neurophysiology of Backward Visual Masking: Information Analysis

1999 ◽  
Vol 11 (3) ◽  
pp. 300-311 ◽  
Author(s):  
Edmund T. Rolls ◽  
Martin J. Tovée ◽  
Stefano Panzeri
Keyword(s):  
Visual Processing ◽  
Visual Information ◽  
Computational Models ◽  
Direct Evidence ◽  
Visual Masking ◽  
Neuronal Response ◽  
Short Soas ◽  
Stimulus Onset ◽  
Backward Masking ◽  
Neuronal Responses

Backward masking can potentially provide evidence of the time needed for visual processing, a fundamental constraint that must be incorporated into computational models of vision. Although backward masking has been extensively used psychophysically, there is little direct evidence for the effects of visual masking on neuronal responses. To investigate the effects of a backward masking paradigm on the responses of neurons in the temporal visual cortex, we have shown that the response of the neurons is interrupted by the mask. Under conditions when humans can just identify the stimulus, with stimulus onset asynchronies (SOA) of 20 msec, neurons in macaques respond to their best stimulus for approximately 30 msec. We now quantify the information that is available from the responses of single neurons under backward masking conditions when two to six faces were shown. We show that the information available is greatly decreased as the mask is brought closer to the stimulus. The decrease is more marked than the decrease in firing rate because it is the selective part of the firing that is especially attenuated by the mask, not the spontaneous firing, and also because the neuronal response is more variable at short SOAs. However, even at the shortest SOA of 20 msec, the information available is on average 0.1 bits. This compares to 0.3 bits with only the 16-msec target stimulus shown and a typical value for such neurons of 0.4 to 0.5 bits with a 500-msec stimulus. The results thus show that considerable information is available from neuronal responses even under backward masking conditions that allow the neurons to have their main response in 30 msec. This provides evidence for how rapid the processing of visual information is in a cortical area and provides a fundamental constraint for understanding how cortical information processing operates.

scholarly journals The Rapid Extraction of Gist—Early Neural Correlates of High-level Visual Processing

2012 ◽  
Vol 24 (2) ◽  
pp. 521-529 ◽  
Author(s):  
Frank Oppermann ◽  
Uwe Hassler ◽  
Jörg D. Jescheniak ◽  
Thomas Gruber
Keyword(s):  
Visual Processing ◽  
Time Course ◽  
Occipital Cortex ◽  
Stimulus Onset ◽  
Gamma Band ◽  
Oscillatory Activity ◽  
Rapid Extraction ◽  
The Right ◽  
High Level ◽  
Individual Objects

The human cognitive system is highly efficient in extracting information from our visual environment. This efficiency is based on acquired knowledge that guides our attention toward relevant events and promotes the recognition of individual objects as they appear in visual scenes. The experience-based representation of such knowledge contains not only information about the individual objects but also about relations between them, such as the typical context in which individual objects co-occur. The present EEG study aimed at exploring the availability of such relational knowledge in the time course of visual scene processing, using oscillatory evoked gamma-band responses as a neural correlate for a currently activated cortical stimulus representation. Participants decided whether two simultaneously presented objects were conceptually coherent (e.g., mouse–cheese) or not (e.g., crown–mushroom). We obtained increased evoked gamma-band responses for coherent scenes compared with incoherent scenes beginning as early as 70 msec after stimulus onset within a distributed cortical network, including the right temporal, the right frontal, and the bilateral occipital cortex. This finding provides empirical evidence for the functional importance of evoked oscillatory activity in high-level vision beyond the visual cortex and, thus, gives new insights into the functional relevance of neuronal interactions. It also indicates the very early availability of experience-based knowledge that might be regarded as a fundamental mechanism for the rapid extraction of the gist of a scene.

Utility of indocyanine green in the detection of radiologically silent hemangioblastomas: case report

2021 ◽  
pp. 1-7
Author(s):  
Alice Senta Ryba ◽  
Juan Sales-Llopis ◽  
Stefan Wolfsberger ◽  
Aki Laakso ◽  
Roy Thomas Daniel ◽  
...  
Keyword(s):  
Indocyanine Green ◽  
Histological Analysis ◽  
Complete Resection ◽  
Fluorescent Imaging ◽  
Cerebellar Hemisphere ◽  
Potential Applications ◽  
Left Cerebellar Hemisphere ◽  
Future Treatments ◽  
Cerebellar Mass ◽  
Suboccipital Approach

Hemangioblastomas (HBs) are rare, benign, hypervascularized tumors. Fluorescent imaging with indocyanine green (ICG) can visualize tumor angioarchitecture. The authors report a case of multiple HBs involving two radiologically silent lesions only detected intraoperatively by ICG fluorescence. A 26-year-old woman presented with a cystic cerebellar mass on the tentorial surface of the left cerebellar hemisphere on MRI. A left paramedian suboccipital approach was performed to remove the mural nodule with the aid of ICG injection. The first injection, applied just prior to removing the nodule, highlighted the tumor and vessels. After resection, two new lesions, invisible on the preoperative MRI, surprisingly enhanced on fluorescent imaging 35 minutes after the ICG bolus. Both silent lesions were removed. Histological analysis of all three lesions revealed they were positive for HB. The main goal of this report is to hypothesize possible explanations about the mechanism that led to the behavior of the two silent lesions. Intraoperative ICG videoangiography was useful to understand the 3D angioarchitecture and HB flow patterns to perform a safe and complete resection in this case. Understanding the HB ultrastructure and pathophysiological mechanisms, in conjunction with the properties of ICG, may expand potential applications for their diagnosis and future treatments.

scholarly journals Responses of Anterior Superior Temporal Polysensory (STPa) Neurons to “Biological Motion” Stimuli

1994 ◽  
Vol 6 (2) ◽  
pp. 99-116 ◽  
Author(s):  
M. W. Oram ◽  
D. I. Perrett
Keyword(s):  
Biological Motion ◽  
Temporal Cortex ◽  
The Body ◽  
Body Motion ◽  
Whole Body ◽  
Global Pattern ◽  
Lighting Conditions ◽  
Specific Direction ◽  
Direction Of Movement ◽  
Light Stimuli

Cells have been found in the superior temporal polysensory area (STPa) of the macaque temporal cortex that are selectively responsive to the sight of particular whole body movements (e.g., walking) under normal lighting. These cells typically discriminate the direction of walking and the view of the body (e.g., left profile walking left). We investigated the extent to which these cells are responsive under “biological motion” conditions where the form of the body is defined only by the movement of light patches attached to the points of limb articulation. One-third of the cells (25/72) selective for the form and motion of walking bodies showed sensitivity to the moving light displays. Seven of these cells showed only partial sensitivity to form from motion, in so far as the cells responded more to moving light displays than to moving controls but failed to discriminate body view. These seven cells exhibited directional selectivity. Eighteen cells showed statistical discrimination for both direction of movement and body view under biological motion conditions. Most of these cells showed reduced responses to the impoverished moving light stimuli compared to full light conditions. The 18 cells were thus sensitive to detailed form information (body view) from the pattern of articulating motion. Cellular processing of the global pattern of articulation was indicated by the observations that none of these cells were found sensitive to movement of individual limbs and that jumbling the pattern of moving limbs reduced response magnitude. A further 10 cells were tested for sensitivity to moving light displays of whole body actions other than walking. Of these cells 5/10 showed selectivity for form displayed by biological motion stimuli that paralleled the selectivity under normal lighting conditions. The cell responses thus provide direct evidence for neural mechanisms computing form from nonrigid motion. The selectivity of the cells was for body view, specific direction, and specific type of body motion presented by moving light displays and is not predicted by many current computational approaches to the extraction of form from motion.

Dominant SCN2A Mutation Causes Familial Episodic Ataxia and Impairment of Speech Development

2018 ◽  
Vol 49 (06) ◽  
pp. 379-384 ◽  
Author(s):  
Kerstin Becker ◽  
Peter Herkenrath ◽  
Christoph Düchting ◽  
Friederike Körber ◽  
Pablo Landgraf ◽  
...  
Keyword(s):  
Autosomal Dominant ◽  
Index Patient ◽  
Speech Development ◽  
Episodic Ataxia ◽  
Cerebellar Hemisphere ◽  
First Episode ◽  
Whole Exome ◽  
Neurologic Disorders ◽  
Left Cerebellar Hemisphere ◽  
Impaired Speech

AbstractMutations in SCN2A are associated with a heterogeneous clinical spectrum including epilepsy and autism. Here, we have identified a peculiar phenotype associated with vaccination related exacerbations of ataxia. We report the first family with three individuals affected by SCN2A-associated episodic ataxia (EA) with impaired speech development. The index patient manifested his first episode of subacute cerebellar ataxia at the age of 12 months, 3 weeks after vaccinations for measles, mumps, rubella, and varicella. Cranial magnetic resonance imaging showed a lesion of the left cerebellar hemisphere, which was first considered as a potential cause of the ataxia. The patient fully recovered within 3 weeks, but developed three very similar episodes of transient ataxia within the following 24 months. Whole exome sequencing of the index patient revealed a heterozygous autosomal-dominant mutation in SCN2A (NM_021007, c.4949T > C; p.L1650P), which was confirmed in the likewise affected mother, and was then also identified in the younger brother who developed the first episode of ataxia. We hereby extend the recently described spectrum of SCN2A-associated neurologic disorders, emphasizing that SCN2A mutations should also be considered in familial cases of EA. Coincidental imaging findings or other associated events such as immunizations should not protract genetic investigations.

Focal motor seizures with secondary generalization arising in the cerebellum

2002 ◽  
Vol 97 (1) ◽  
pp. 190-196 ◽  
Author(s):  
Ali H. Mesiwala ◽  
John D. Kuratani ◽  
Anthony M. Avellino ◽  
Theodore S. Roberts ◽  
Marcio A. Sotero ◽  
...  
Keyword(s):  
Single Photon ◽  
Photon Emission ◽  
Cerebellar Hemisphere ◽  
Dysplastic Lesion ◽  
Content Type ◽  
Depth Electrodes ◽  
Left Cerebellar Hemisphere ◽  
Eeg Recordings ◽  
Cerebellar Mass ◽  
Secondary Generalization

✓ The issue of whether seizures can arise in the cerebellum remains controversial. The authors present the first known case of focal subcortical epilepsy with secondary generalization thought to arise from a dysplastic lesion within the cerebellum. A newborn infant presented with daily episodes of left eye blinking, stereotyped extremity movements, postural arching, and intermittent altered consciousness lasting less than 1 minute. These episodes began on his 1st day of life and progressively increased in frequency to more than 100 events per day. Antiepileptic medications had no effect, and interictal and ictal scalp electroencephalography (EEG) recordings demonstrated bilateral electrical abnormalities. Magnetic resonance imaging revealed a mass in the left cerebellar hemisphere, and ictal and interictal single-photon emission computerized tomography revealed a focal perfusion abnormality in the region of the cerebellar mass. The patient subsequently underwent intraoperative EEG monitoring with cortical scalp electrodes and cerebellar depth electrodes. Intraoperative EEG recordings revealed focal seizure discharges that arose in the region of the cerebellar mass and influenced electrographic activity in both cerebral hemispheres. Resection of this mass and the left cerebellar hemisphere led to complete resolution of the patient's seizures and normalization of the scalp EEG readings. Neuropathological findings in this mass were consistent with ganglioglioma. A review of the literature on the cerebellar origins of epilepsy is included.

scholarly journals Visual processing and attention rather than face and emotion processing play a distinct role in ASD: an EEG study

2019 ◽  
Author(s):  
Adyasha Tejaswi Khuntia ◽  
Rechu Divakar ◽  
Fabio Apicella ◽  
Filippo Muratori ◽  
Koel Das
Keyword(s):  
Visual Processing ◽  
Emotion Processing ◽  
Autism Spectrum ◽  
Stimulus Onset ◽  
Perceptual Task ◽  
Typically Developing ◽  
Multivariate Pattern Analysis ◽  
Social Reciprocity ◽  
Multivariate Pattern

AbstractAutism Spectrum Disorder results in deficit in social interaction, non-verbal communication and social reciprocity. Cognitive tasks pertaining to emotion processing are often preferred to distinguish the ASD children from the typically developing ones. We analysed the role of face and emotion processing in ASD and explored the feasibility of using EEG as a neural marker for detecting ASD. Subjects performed a visual perceptual task with face and nonface stimuli. Successful ASD detection was possible as early as 50 ms. post stimulus onset. Alpha and Beta oscillations seem to best identify autistic individuals. Multivariate pattern analysis and source localization studies points to the role of early visual processing and attention rather than emotion and face processing in detecting autism.

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