scholarly journals The N1 wave amplitude reflects perceptual grouping and correlates with crowding

2012 ◽  
Vol 12 (9) ◽  
pp. 1296-1296
Author(s):  
V. A. Chicherov ◽  
G. Plomp ◽  
M. H. Herzog
Keyword(s):  
Perceptual Grouping ◽  
Wave Amplitude ◽  
N1 Wave

Interactions of human cord dorsum potential

1976 ◽  
Vol 40 (1) ◽  
pp. 79-84 ◽  
Author(s):  
K. Shimoji ◽  
M. Matsuki ◽  
Y. Ito ◽  
K. Masuko ◽  
M. Maruyama ◽  
...  
Keyword(s):  
Peripheral Nerve ◽  
Epidural Space ◽  
Nerve Stimulation ◽  
Wave Amplitude ◽  
Species Differences ◽  
Repetitive Stimulation ◽  
Positive Wave ◽  
Strong Stimulation ◽  
Weak Stimulation ◽  
N1 Wave

The slow positive wave (P2 wave) of the evoked spinal electrogram was recorded from the posterior epidural space in wakeful man, and studied by applying several modes of peripheral nerve stimulation. With graded stimulation the P2 wave amplitude rapidly reached the maximum at weaker stimulation than that required for the initially positive spikes (P1) and the preceding negative (N1) wave. The “second” component of the P2 appeared during stronger stimulation or during excitemenpt of the subjects. With prolonged repetitive stimulation the P2 wave increased its duration with several summits on the decaying phase. Two interactions were observed between the P2 waves produced by conditioning and testing stimulations in the same or different nerves: inhibition or occlusion by strong stimulation and faciliation by weak stimulation. Thus, the characteristic of the P2 wave in man was similar in part to that of the positive wave observed in decerebrate animals, and differnt in other ways presumably due to influences from supraspinal structures or species differences.

Density Wave Measurements in a Rectangular Clarifier

1983 ◽  
Vol 18 (1) ◽  
pp. 129-150 ◽  
Author(s):  
Mark K. Watson ◽  
R.R. Hudgins ◽  
P.L. Silveston
Keyword(s):  
Power Spectrum ◽  
Internal Wave ◽  
Internal Waves ◽  
Wave Motion ◽  
Wave Amplitude ◽  
Suspended Solids ◽  
Small Volume ◽  
Density Wave ◽  
Measure Concentration ◽  
Wave Measurements

Abstract Internal wave motion was studied in a laboratory rectangular, primary clarifier. A photo-extinction device was used as a turbidimeter to measure concentration fluctuations in a small volume within the clarifier as a function of time. The signal from this device was fed to a HP21MX minicomputer and the power spectrum plotted from data records lasting approximately 30 min. Results show large changes of wave amplitude as frequency increases. Two distinct regions occur: one with high amplitudes at frequencies below 0.03 Hz, the second with very small amplitudes appears for frequencies greater than 0.1 Hz. The former is associated with internal waves, the latter with flow-generated turbulence. Depth, velocity in the clarifier and inlet suspended solids influence wave amplitudes and the spectra. A variation with position or orientation of the probe was not detected. Contradictory results were found for the influence of flow contraction baffles on internal wave amplitude.

scholarly journals Time Course of ECG Depolarization and Repolarization Changes during Ischemia in PTCA Recordings

2004 ◽  
Vol 43 (01) ◽  
pp. 43-46 ◽  
Author(s):  
J. García ◽  
G. Wagner ◽  
R. Bailón ◽  
L. Sörnmo ◽  
P. Laguna ◽  
...  
Keyword(s):  
Time Course ◽  
Wave Amplitude ◽  
Temporal Evolution ◽  
Delayed Response ◽  
S Wave ◽  
Ecg Changes ◽  
T Complex ◽  
Karhunen Loeve Transform ◽  
Low Amplitude ◽  
Electrocardiogram Ecg

Summary Objectives: In this work we studied the temporal evolution of changes in the electrocardiogram (ECG) as a consequence of the induced ischemia during prolonged coronary angioplasty, comparing the time course of indexes reflecting depolarization and those reflecting repolarization. Methods: We considered both local (measured at specific points of the ECG) and global (obtained from the Karhunen-Loève transform) indexes. In particular, the evolution of Q, R and S wave amplitudes during ischemia was analyzed with respect to classical indexes such as ST level. As a measurement of sensitivity we used an Ischemic Changes Sensor (ICS), which reflects the capacity of an index to detect changes in the ECG. Results: The results showed that, in leads with low-amplitude ST-T complexes, the S wave amplitude was more sensitive in detecting ischemia than was the commonly used index ST60. It was found that in such leads the S wave amplitude initially exhibited a delayed response to ischemia when compared to ST60, but its performance was better from the second minute of occlusion. The global indexes describing the ST-T complex were, in terms of the ICS, superior to the S wave amplitude for ischemia detection. Conclusions: Ischemic ECG changes occur both at repolarization and depolarization, with alterations in the depolarization period appearing later in time. Local indexes are less sensitive to ischemia than global ones.

Sign in / Sign up

Export Citation Format

Share Document