Initially, psychometric functions were measured for the detection of amplitude modulation (AM) or frequency modulation (FM), using a two-alternative forced-choice (2AFC) task. Carrier frequencies were 125, 1000, and 6000 Hz, and modulation rates were 2, 5, and 10 Hz. For the two lower carrier frequencies, FM detection tended to be best at the lowest modulation rate while AM detection was best a...

Complex natural sounds (e.g., animal vocalizations or speech) can be characterized by specific spectrotemporal patterns whose components change in both frequency (frequency modulation, FM) and amplitude (amplitude modulation, AM). The neural coding of AM and FM has been widely studied in humans and animals, but typically with either pure AM or pure FM stimuli. The neural mechanisms employed to ...

This article is concerned with the detection of mixed modulation (MM), i.e., simultaneously occurring amplitude modulation (AM) and frequency modulation (FM). In experiment 1, an adaptive two-alternative forced-choice task was used to determine thresholds for detecting AM alone. Then, thresholds for detecting FM were determined for stimuli which had a fixed amount of AM in the signal interval o...

H. J. De Los Santos et al., Radio Systems Engineering, DOI 10.1007/978-3-319-07326-2_2, © The Authors 2015 Abstract In this chapter, we present a number of topics surrounding modulation and demodulation. We begin by introducing system-level block diagrams of AM and FM/PM modulators and demodulators, and explaining their respective principles of operation. In particular, under the topic of AM Mo...

Lawrence Der, Ph.D. Silicon Laboratories Inc. Introduction Edwin H. Armstrong, known as one of the founding fathers of radio technology, invented the superheterodyne radio receiver in 1918 and frequency modulation (FM) in 1933 [1]. These two concepts, along with his regenerative circuit technique developed in 1912, formed the basis of radio frequency electronics as we know it today. In the Unit...

Fibromyalgia (FM) is characterized by widespread pain, as well as affective disturbance (eg, depression). Given that emotional processes are known to modulate pain, a disruption of emotion and emotional modulation of pain and nociception may contribute to FM. The present study used a well-validated affective picture-viewing paradigm to study emotional processing and emotional modulation of pain...

A natural sound can be described by dynamic changes in envelope (amplitude) and carrier (frequency), corresponding to amplitude modulation (AM) and frequency modulation (FM), respectively. Although the neural responses to both AM and FM sounds are extensively studied in both animals and humans, it is uncertain how they are corepresented when changed simultaneously but independently, as is typic...

Conventional digital halftoning approaches function by modulating either the dot size (amplitude modulation or AM) or the dot density (frequency modulation or FM). Generally, AM halftoning methods have the advantages of low computation and good print stability, while FM halftoning methods typically have higher spatial resolution and resistance to Moiré artifacts. In this paper, we present a new...

Conventional digital halftoning approaches function by modulating either the dot size [amplitude modulation (AM)] or the dot density [frequency modulation (FM)]. Generally, AM halftoning methods have the advantage of low computation and good print stability, while FM halftoning methods typically have higher spatial resolution and resistance to moiré artifacts. In this paper, we present a new cl...