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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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Salt Bridge Artifacts

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Dr. Rishabh Pathak

Salt bridge artifacts are a type of artifact that can affect EEG recordings. 

1.     Description:

o Nature: Salt bridge artifacts occur when there is a merging of electrode locations through the formation of a salt bridge, leading to electrical disturbances in EEG signals.

o  Appearance: These artifacts manifest as flat, low-amplitude activity that can be channel-specific and may appear close to isoelectric, resembling a stable baseline.

o Waveform: Salt bridge artifacts differ from other artifacts by being lower in amplitude, lacking low-frequency oscillations, and often affecting only one channel.

oLocalization: The occurrence of salt bridge artifacts is specific to the channels that include the combined electrodes, reflecting the impact of the salt bridge on signal amplification.

2.   Causes:

oFormation: Salt bridge artifacts result from the smearing of electrode paste between electrodes, creating a salt bridge that merges electrode locations and alters electrical properties.

oEffect: The merging of electrode locations through salinity affects the impedance and signal characteristics, leading to the generation of salt bridge artifacts in EEG recordings.

3.   Differentiation:

oComparison with Perspiration Artifacts: Salt bridge artifacts share similarities with perspiration artifacts in terms of electrode merging but differ in amplitude, stability, and waveform characteristics.

oAmplitude and Stability: Salt bridge artifacts are characterized by lower amplitude and more stable activity compared to perspiration artifacts.

4.   Recognition:

oVisual Cue: The flat and low-amplitude activity in specific channels, along with the absence of low-frequency oscillations, serves as a visual cue for identifying salt bridge artifacts in EEG recordings.

oConfirmation: Observing the channel-specific nature and stable characteristics of the artifact can help confirm the presence of salt bridge artifacts in EEG data.

Understanding the characteristics and origins of salt bridge artifacts is crucial for EEG technicians and clinicians to distinguish and manage these disturbances during EEG recording and interpretation. Proper identification and mitigation of salt bridge artifacts contribute to the quality and reliability of EEG data analysis in clinical and research settings.

 

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Comments

  1. SRIJuly 10, 2024 at 2:00 AM

    Amazing @Dr. Rishabh Thanks for sharing your incredible knowledge bank with us.

    ReplyDelete

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