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...
Blink artifacts
in EEG recordings are a common type of ocular artifact caused by the rapid
movement of the eyes during blinking.
Nature of Blink
Artifacts:
o Blink artifacts
are characterized by the rapid movement of the eyes both upward and downward
during blinking.
o The artifact
appears as a bifrontal, diphasic, synchronous slow wave with a field limited to
the frontal region.
o The slope and
duration of the artifactual wave are related to the rate of eye movement and
the duration of the eye closure.
2. Characteristics:
o The amplitude of
the blink artifact decreases quickly with greater distance from the orbits,
with the field declining steeply beyond its maximum in the region of the orbits.
o Despite its high
amplitude in the anterior region, the artifact is not present in the central
region due to the field distribution.
o The direction of
the artifact's deflection within the EEG depends on the montage used but always
indicates a changing electropositive field at the frontal poles.
3. Differentiation:
o Blink artifacts
closely resemble isolated slow waves, and their waveform can be differentiated
from other patterns by their characteristics.
o Using both
supraorbital and infraorbital electrodes is a definitive means for
differentiation of ocular artifacts, including blink artifacts.
o The presence or
absence of eye movements, along with waveform differences, can help in
distinguishing blink artifacts from other EEG patterns.
Understanding the
nature, characteristics, and differentiation of blink artifacts is essential
for EEG interpretation to avoid misinterpretation of these common ocular
artifacts as pathological brain activity.
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