negative modulation

negative modulation

[′neg·əd·iv ‚mäj·ə′lā·shən]
(electronics)
Modulation in which an increase in brightness corresponds to a decrease in amplitude-modulated transmitter power; used in United States television transmitters and in some facsimile systems.
Modulation in which an increase in brightness corresponds to a decrease in the frequency of a frequency-modulated facsimile transmitter. Also known as negative transmission.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
The Belar AMMA-2 is a DSP-based, microprocessor-controlled AM modulation monitor that precisely measures and analyzes positive and negative modulation and carrier level.
Another study in the same direction reported that the structures overlapping DMN (prefrontal medial cortex, ventral anterior cingulate, and precuneus) showed a negative modulation or deactivation to emotional stimuli, which suggests that DMN participates in the monitoring of internal emotional processing [29].
Pairwise comparisons indicated that the difference was between control and fear conditions (P = 0.003); this component showed a negative modulation during the fear condition.
This analysis, in which the sensory-motor control condition was included, allowed observing that the negative modulation of IC2 "parahippocampal-prefrontal" included structures involved in emotional face processing.
Another interesting finding was the negative modulation of IC2 which, as mentioned previously, includes regions involved in emotional processing.
In order to understand the type of modulation of the ICs of interest (i.e., IC4 had a positive modulation in the fear condition while IC2 presented a negative modulation to facial stimuli), the coefficients of temporal correlation between the onsets of fear and the time courses of these two components were reviewed.
As a limitation of the present study we refer to the phenomenon of reappraisal of emotional stimuli as a possible mechanism that may be related to the negative modulation of IC2.