Biomaterial Database

Detection of frequency modulation in the FM-bat Phyllostomus discolor. 1996

K H Esser, and R Kiefer

Abteilung Vergleichende Neurobiologie, Universität Ulm, Germany.

In a two-alternative forced-choice procedure lesser spear-nosed bats, Phyllostomus discolor, had to discriminate between a pure tone stimulus and a sinusoidally frequency-modulated signal generated at the same carrier frequency as the tone. Modulation depths of the SFM stimuli were reduced until the animals' performance dropped below the 75%-correct level which was used to determine difference limens for detection of frequency modulation (FMDL). The dependence of FMDLs on modulation and carrier frequency was systematically investigated. For a carrier frequency of 18.5 kHz, average FMDLs increased from 95 Hz at a modulation frequency of 10 Hz to 820 Hz at a modulation frequency of 2000 Hz which corresponds to Weber ratios (2 delta f/f) of 0.005 and 0.044 respectively. Further, difference limens were found to increase linearly in proportion to carrier frequency throughout a major part (9-74 kHz) of the species' hearing range. In comparison to other mammals, P. discolor has a pronounced capability for frequency discrimination which might be related to the extensive use of individually distinct frequency-modulated communication calls and audio-vocal learning.

UI	MeSH Term	Description	Entries
D008144	Loudness Perception	The perceived attribute of a sound which corresponds to the physical attribute of intensity.	Loudness Perceptions,Perception, Loudness,Perceptions, Loudness
D008297	Male		Males
D010898	Pitch Perception	A dimension of auditory sensation varying with cycles per second of the sound stimulus.	Perception, Pitch,Perceptions, Pitch,Pitch Perceptions
D002138	Calibration	Determination, by measurement or comparison with a standard, of the correct value of each scale reading on a meter or other measuring instrument; or determination of the settings of a control device that correspond to particular values of voltage, current, frequency or other output.	Calibrations
D002685	Chiroptera	Order of mammals whose members are adapted for flight. It includes bats, flying foxes, and fruit bats.	Bats,Flying Foxes,Horseshoe Bats,Pteropodidae,Pteropus,Rhinolophus,Rousettus,Bat, Horseshoe,Bats, Horseshoe,Foxes, Flying,Horseshoe Bat
D002755	Choice Behavior	The act of making a selection among two or more alternatives, usually after a period of deliberation.	Approach Behavior,Approach Behaviors,Behavior, Approach,Behavior, Choice,Behaviors, Approach,Behaviors, Choice,Choice Behaviors
D003216	Conditioning, Operant	Learning situations in which the sequence responses of the subject are instrumental in producing reinforcement. When the correct response occurs, which involves the selection from among a repertoire of responses, the subject is immediately reinforced.	Instrumental Learning,Learning, Instrumental,Operant Conditioning,Conditionings, Operant,Instrumental Learnings,Learnings, Instrumental,Operant Conditionings
D004455	Echolocation	An auditory orientation mechanism involving the emission of high frequency sounds which are reflected back to the emitter (animal).	Echolocations
D005583	Fourier Analysis	Analysis based on the mathematical function first formulated by Jean-Baptiste-Joseph Fourier in 1807. The function, known as the Fourier transform, describes the sinusoidal pattern of any fluctuating pattern in the physical world in terms of its amplitude and its phase. It has broad applications in biomedicine, e.g., analysis of the x-ray crystallography data pivotal in identifying the double helical nature of DNA and in analysis of other molecules, including viruses, and the modified back-projection algorithm universally used in computerized tomography imaging, etc. (From Segen, The Dictionary of Modern Medicine, 1992)	Fourier Series,Fourier Transform,Analysis, Cyclic,Analysis, Fourier,Cyclic Analysis,Analyses, Cyclic,Cyclic Analyses,Series, Fourier,Transform, Fourier
D000161	Acoustic Stimulation	Use of sound to elicit a response in the nervous system.	Auditory Stimulation,Stimulation, Acoustic,Stimulation, Auditory