Some of the causes in children for Dark circles under eyes in children may include: 1  Lack of sleep. 2  Nasal congestion. 3  Black eye due to trauma.  Frequent eye 1  rubbing. Hayfever.  Inherited 1  trait. Dehydration. 2  Allergies. 3  Eczema. Phenol sulfotransferase deficiency.
From From P300 Development across the Lifespan: A Systematic Review and Meta-Analysis. The latency and amplitude of the P300 response may vary as a function of age. The P300 (P3) wave is an event related potential (ERP) component elicited in the process of decision making.pplications in brain-computer interfacing (BCI) have also been proposed. The P300 has a number of desirable qualities that aid in implementation of such systems. First, the waveform is consistently detectable and is elicited in response to precise stimuli.
It's this change that generates the electrical impulse that starts the heart's contraction. So we can associate the P wave of an ECG with the contraction of the atria. QRS Wave. If we move along the graph of the ECG, we see a small dip followed by a large spike and another dip. This series is usually considered together, and it's called the QRS wave.