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Uncertainty in Multiclass Classification

Dr. Rishabh Pathak
1. What is Uncertainty in Classification? Uncertainty refers to the model’s confidence or doubt in its predictions. Quantifying uncertainty is important to understand how reliable each prediction is. In multiclass classification , uncertainty estimates provide probabilities over multiple classes, reflecting how sure the model is about each possible class. 2. Methods to Estimate Uncertainty in Multiclass Classification Most multiclass classifiers provide methods such as: predict_proba: Returns a probability distribution across all classes. decision_function: Returns scores or margins for each class (sometimes called raw or uncalibrated confidence scores). The probability distribution from predict_proba captures the uncertainty by assigning a probability to each class. 3. Shape and Interpretation of predict_proba in Multiclass Output shape: (n_samples, n_classes) Each row corresponds to the probabilities of ...
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Polymicrogyria is an Organization Disorder Associated with Many Small Folds.

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Dr. Rishabh Pathak

Polymicrogyria is a developmental malformation of the human brain characterized by an excessive number of small folds. Here are key points regarding polymicrogyria as an organization disorder associated with many small folds:


1. Definition: Polymicrogyria is a cortical malformation characterized by an increased number of small and abnormally formed gyri (folds) on the surface of the brain. These numerous small folds give the cortex a "micropolygyric" appearance, in contrast to the typical larger gyri seen in a healthy brain.


2.     Neuronal Organization: Polymicrogyria is considered an organization disorder because it involves disturbances in the normal organization of the cortical layers and neuronal connectivity. The increased cellular necrosis and disrupted neuronal connectivity in polymicrogyria lead to a thinned cortex with an excessive number of small irregular folds, affecting the structural integrity and functional connectivity of the brain regions.


3.     Clinical Features: Individuals with polymicrogyria may present with a range of neurological symptoms, including developmental delay, intellectual disability, seizures, motor impairments, and speech and language difficulties. The clinical manifestations can vary depending on the extent and location of the polymicrogyric changes in the brain.


4.     Genetic and Acquired Causes: Polymicrogyria can have both genetic and acquired causes. Genetic mutations in various genes have been associated with polymicrogyria, affecting processes critical for brain development. Acquired factors such as prenatal insults, infections, or vascular disruptions can also contribute to the development of polymicrogyria.


5. Diagnostic Evaluation: Diagnosis of polymicrogyria typically involves neuroimaging studies, such as MRI, which can reveal the characteristic small and irregular gyri on the brain surface. Genetic testing may be considered to identify underlying genetic factors contributing to polymicrogyria in some cases. The pattern and distribution of polymicrogyric changes can help differentiate it from other cortical malformations.


6. Management and Prognosis: Management of polymicrogyria focuses on addressing the individual's specific symptoms and needs. Treatment may include antiepileptic medications for seizure control, early intervention services for developmental support, physical and occupational therapy, and other supportive measures. The prognosis for individuals with polymicrogyria varies depending on the extent of brain involvement and associated complications.


In summary, polymicrogyria is an organization disorder characterized by an excessive number of small folds on the brain surface, resulting from disruptions in neuronal organization and connectivity during brain development. Understanding the genetic, clinical, and diagnostic aspects of polymicrogyria is essential for accurate diagnosis, management, and support for individuals affected by this cortical malformation.

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