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Energy Manifold Natural Gradient Descent: From Riemannian Optimization to Modern Neuroscience, NeuroAI and Quantum Physics

Dr. Rishabh Pathak
When Geometry, Energy, Artificial Intelligence and Neuroscience Converge Modern Artificial Intelligence is rapidly moving beyond the idea that learning simply means minimizing an error function. Increasingly, researchers are asking a deeper question: what is the structure of the space in which learning takes place? This question becomes particularly important when the system being modelled is constrained, nonlinear, dynamic, or governed by physical principles. A recent work titled “Energy Manifold Natural Gradient Descent: Riemannian Optimization for Neural PDE Solvers” , by Zhangyong Liang and Huanhuan Gao, introduces Energy Manifold Natural Gradient Descent (EMNGD) , a mathematical framework that extends energy-based natural-gradient optimization from unconstrained Euclidean parameter spaces to constrained Riemannian parameter manifolds . At its core, the framework proposes a simple but powerful principle: An optimization algorithm should not only determine how to reduce error; it sh...
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Ballistocardiographic

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Dr. Rishabh Pathak

Ballistocardiographic artifacts are another type of mechanical cardiac artifact that can be observed in EEG recordings. 

1.     Ballistocardiographic Artifacts:

o Description: Ballistocardiographic artifacts result from slight movements of the head or body that occur with cardiac contractions, leading to waveform distortions in EEG recordings.

o    Characteristics:

§ Source: Arises from the pulsatile force on the aortic arch due to the redirection of blood flow during cardiac contractions.

§ Appearance: Ballistocardiographic artifacts exhibit waveforms similar to pulse artifacts but are more widespread in distribution.

o    Identification:

§ Location: These artifacts may involve one or a few electrodes if due to electrode lead movement, or a collection of posterior electrodes if due to head movement when the patient is supine.

§  Alteration: Repositioning the head or neck on a pillow can sometimes alter the appearance of ballistocardiographic artifacts in EEG recordings.

o    Differentiation:

§  From Pulse Artifacts: Understanding the distribution and characteristics of ballistocardiographic artifacts helps differentiate them from pulse artifacts in EEG recordings.

§ From Other Artifacts: Recognizing the unique waveform patterns and distribution of ballistocardiographic artifacts aids in distinguishing them from other types of artifacts present in EEG recordings.

Accurate identification and differentiation of ballistocardiographic artifacts in EEG recordings are essential for ensuring the quality and reliability of EEG data for clinical assessments and research purposes. Understanding the distinct features of ballistocardiographic artifacts can help researchers and clinicians interpret EEG recordings accurately and avoid misinterpretations caused by these mechanical cardiac artifacts.

 

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