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.
The T wave is the most labile wave in the ECG. T wave changes including low-amplitude T waves and abnormally inverted T waves may be the result of many cardiac and non-cardiac conditions. The normal T wave is usually in the same direction as the QRS except in the right precordial leads (see V2 below). Also, the normal T wave is asymmetric with the first half moving more slowly than the second half. In the normal ECG (see below) the T wave is always upright in leads I, II, V3-6, and always inverted in lead aVR. The other leads are variable depending on the direction of the QRS and the age of the patient.