Skip to main content

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...
Post a Comment

Cone Waves Compared to Positive Occipital Sharp Transients of Sleep

Image
Dr. Rishabh Pathak

Cone waves and Positive Occipital Sharp Transients of Sleep (POSTS) are distinct EEG patterns that share some similarities but also have key differences. Here is a comparison between cone waves and POSTS:


1.     Morphology:

o  Both cone waves and POSTS exhibit a triangular morphology, with a sharp, distinctive shape resembling a cone.

o Cone waves and POSTS may appear similar in their waveform characteristics, including the presence of a sharp onset and offset.

2.   Occipital Distribution:

oBoth cone waves and POSTS are typically localized over the occipital regions of the brain.

o The occipital distribution of these waveforms distinguishes them from patterns that are more widespread or localized to other brain regions.

3.   Duration:

o Cone waves have a duration typically more than 250 milliseconds, while POSTS have a shorter duration, typically less than 200 milliseconds.

o The difference in duration can aid in distinguishing between cone waves and POSTS on EEG recordings.

4.   Age Dependency:

o Cone waves are more likely to occur in younger children, typically between the ages of 6 months and 3 years.

o POSTS are rare before 3 years of age and most common after childhood, indicating an age-dependent occurrence.

5.    Phase Reversal:

o POSTS are characterized by a phase reversal, with positivity at the center of the field, which is evident in the waveform.

o Cone waves do not exhibit a phase reversal in the same manner as POSTS, providing a distinguishing feature between the two patterns.

6.   Clinical Significance:

o Cone waves are considered a normal variant with no clinical significance in their presence or absence.

o POSTS, while also a normal variant, may have implications for EEG interpretation and clinical assessment due to their association with specific age groups and sleep states.

7.    Co-occurring Waves:

o Cone waves occur during non-rapid eye movement (NREM) sleep and are accompanied by other EEG features of this state, such as diffuse theta or delta background activity.

o POSTS are also observed during NREM sleep and may co-occur with other sleep-related EEG patterns, such as sleep spindles and K complexes.

Understanding the similarities and differences between cone waves and POSTS is essential for accurate EEG interpretation and recognition of normal variants versus abnormal patterns. By considering the unique characteristics of each waveform, clinicians can effectively differentiate between cone waves and POSTS in EEG recordings and assess their clinical significance in the context of patient evaluation.

 

Categories:

Comments

Post a Comment

Popular posts from this blog

Review Settings of EEG

Dr. Rishabh Pathak
The review settings of an EEG recording refer to the parameters that can be adjusted to optimize the visualization and interpretation of electrical brain activity. Here is an overview of the key review settings in EEG analysis: 1.       Amplification (Gain/Sensitivity) : o Definition : Amplification, also known as gain or sensitivity, determines how much the electrical signals from the brain are amplified before being displayed on the EEG recording. o Measurement : Typically measured in microvolts per millimeter (μV/mm). o Impact : Adjusting the amplification setting can affect the visibility of high-amplitude and low-amplitude activity. High-amplitude activity may require vertical compression to fit within the display range, while low-amplitude activity may require lower sensitivity settings for better visualization. 2.      Frequency Filtering : o Bandpass : The frequency range within which EEG signals are analyzed. Common settings include ...
Post a Comment
Read more

Cancellous Bone

Dr. Rishabh Pathak
Cancellous bone, also known as trabecular or spongy bone, is the other main type of bone tissue found in the human skeleton alongside cortical bone. Cancellous bone has a porous and lattice-like structure, providing flexibility, shock absorption, and a site for hematopoiesis (blood cell formation). Here are key features and characteristics of cancellous bone: 1.     Structure : o     Trabeculae : Cancellous bone is composed of a network of thin, bony trabeculae that form an interconnected lattice structure. o     Bone Marrow : The spaces between trabeculae contain red bone marrow, which is involved in the production of blood cells (hematopoiesis). o     Less Compact : Cancellous bone is less dense and compact than cortical bone, with a higher surface area-to-volume ratio. 2.     Composition : o     Trabecular Bone : The trabeculae are made up of lamellae, osteocytes, and canaliculi similar to corti...
Post a Comment
Read more

Amphiarthrodial or Cartilaginous Joints

Dr. Rishabh Pathak
Amphiarthrodial joints, also known as cartilaginous joints, are joints where the adjacent bones are connected by cartilage. These joints allow for limited movement and provide both stability and flexibility to the skeletal system. Here is an overview of amphiarthrodial or cartilaginous joints: Amphiarthrodial or Cartilaginous Joints: 1.     Structure : o     Cartilage : §   Amphiarthrodial joints are characterized by the presence of cartilage between the articulating surfaces of the bones. §   The cartilage can be hyaline cartilage or fibrocartilage, depending on the specific joint and its function. o     Lack of Joint Cavity : §   Similar to fibrous joints, cartilaginous joints do not have a synovial cavity, and the bones are held together by the cartilaginous tissue. 2.     Types : o     Synchondroses : §   Synchondroses are cartilaginous joints where the connecting material is hyaline carti...
Post a Comment
Read more

Cell Maturation (Dendrite and Axon Growth)

Dr. Rishabh Pathak
Cell maturation, encompassing dendrite and axon growth, is a crucial stage of brain development where neurons undergo structural changes to establish connections and form functional neural circuits. Here is an overview of cell maturation in the context of dendrite and axon growth: 1.      Dendrite Growth : o     Definition : Dendrites are branched extensions of a neuron that receive signals from other neurons and transmit these signals to the cell body. o     Dendritic Arborization : During maturation, neurons extend and elaborate their dendritic arbors, increasing the surface area available for synaptic connections. o     Synaptic Integration : Dendritic growth is essential for forming synapses with other neurons, allowing for the integration of incoming signals and information processing. o     Activity-Dependent Plasticity : Dendritic growth can be influenced by neural activity and sensory experiences, sh...
Post a Comment
Read more

Elements Selection Techniques

Dr. Rishabh Pathak
Element selection techniques play a crucial role in determining how individual elements or units are chosen from the population to form a sample. Here are some common element selection techniques used in sampling: 1.     Unrestricted Sampling : §   In unrestricted sampling, each element in the population has an equal chance of being selected for the sample. This approach is commonly used in simple random sampling, where every element is selected independently of other elements. 2.     Restricted Sampling : §   Restricted sampling involves imposing certain restrictions or conditions on the selection of sample elements. This can include stratification, clustering, or other criteria that guide the selection process. Restricted sampling techniques include: §   Stratified Sampling: The population is divided into homogeneous subgroups (strata), and samples are selected from each stratum to ensure representation of different characteristics. § ...
Post a Comment
Read more