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R R Fay

Publications and source records attributed to R R Fay.

At least 37 records · Page 2Linked to original sources
PubMed1995

Perception of spectrally and temporally complex sounds by the goldfish (Carassius auratus).

Behavioral studies on complex sound perception in goldfish were carried out in order to help determine what, if any, differences exist between the sense of hearing of fishes and other vertebrates. A stimulus generalization paradigm was used with classical conditioning in three experiments to determine: (1) the perceptual relations between a pure tone and harmonic complexes having a fundamental frequency equal to that of the tone; (2) the combined effects on perception of pulse repetition rate and spectral envelope; and (3) whether goldfish can be shown to identify a complex source when presented simultaneously with another complex source. Experiment 1 showed that the perceptions of tones and harmonic complexes differ profoundly even for the cases in which they have common periodicities and frequency components. Experiment 2 demonstrated that pulse repetition rate and spectral location simultaneously control behavior, and that repetition rate exerts behavioral control independent of spectral location. Experiment 3 indicates that goldfish did not 'hear out' or analyze a complex target source within a mixture of complex sources. In general, goldfish appear to be aware of multiple acoustic dimensions of complex sounds, suggesting both pitch-like and timbre-like perceptual dimensions. These results do not permit a qualitative distinction between the sense of hearing of goldfish and that of other vertebrates.

Acoustic Stimulation↗
PubMed1995

Physiology of primary saccular afferents of goldfish: implications for Mauthner cell response.

Mauthner cells receive neurally coded information from the otolith organs in fishes, and it is most likely that initiation and directional characteristics of the C-start response depend on this input. In the goldfish, saccular afferents are sensitive to sound pressure (< -30 dB re: 1 dyne cm-2) in the most sensitive frequency range (200 to 800 Hz). This input arises from volume fluctuations of the swimbladder in response to the sound pressure waveform and is thus nondirectional. Primary afferents of the saccule, lagena, and utricle of the goldfish also respond with great sensitivity to acoustic particle motion (< 1 nanometer between 100 and 200 Hz). This input arises from the acceleration of the fish in a sound field and is inherently directional. Saccular afferents can be divided into two groups based on their tuning: one group is tuned at about 250 Hz, and the other tuned between 400 Hz and 1 kHz. All otolithic primary afferents phaselock to sinusoids throughout the frequency range of hearing (up to about 2 kHz). Based on physiological and behavioral studies on Mauthner cells, it appears that highly correlated binaural input to the M-cell, from the sacculi responding to sound pressure, may be required for a decision to respond but that the direction of the response is extracted from small deviations from a perfect interaural correlation arising from the directional response of otolith organs to acoustic particle motion.

Animals↗
PubMed1994

Perception of temporal acoustic patterns by the goldfish (Carassius auratus).

The perception of temporal acoustic patterns was studied in the goldfish using classical respiratory conditioning in combination with a stimulus generalization paradigm. Stimuli consisted of a bandpass filtered pulse repeated in various periodic and aperiodic temporal patterns. In each of 14 experiments, animals received 40 conditioning trials to a given stimulus pattern and were then tested for generalization to eight novel stimuli differing only in temporal pattern. In experiments 1-5, animals were conditioned to a periodic pulse train with a particular interpulse interval (IPI) and then tested to novel periodic pulse trains with various IPIs. Generalization gradients were substantially symmetric and monotonic with repetition rate, suggesting a perceptual continuum in goldfish that is similar to periodicity pitch or roughness in human listeners. Several additional experiments indicated that the perceptual qualities of simple and complex temporal patterns are not primarily determined by spectral structure or pulse rate, but rather are determined by the distribution of IPIs. A model for the central analysis of IPIs was successful in accounting for the results of experiments in which animals were conditioned to simple, periodic stimuli. However, the model failed when animals were conditioned to more complex stimuli having aperiodic temporal patterns. These experiments demonstrate the potential usefulness of the stimulus generalization paradigm for investigating aspects of complex sound source perception in non-human animals.

Acoustic Stimulation↗
PubMed1993

Acoustic response properties of single units in the torus semicircularis of the goldfish, Carassius auratus.

Single units of the goldfish torus semicircularis (TS) were recorded in response to pure tones. Response areas (RA) were obtained by recording the number of spikes evoked by tones in a range of frequencies and levels within the units' dynamic range. RAs gave estimates of best sensitivity (BS), characteristic frequency (CF), most excitatory frequency at each level (BF), and Q10dB. Peri-stimulus-time histograms (PSTH), interspike interval histograms (ISIH), and period histograms were obtained at various frequencies and levels to describe the units' temporal response patterns. The distribution of CF is nonuniform with modes at 155, 455, and 855 Hz. The distribution of the coefficient of synchronization to standard tones is also nonuniform, revealing a dichotomy between units with little or no phase-locking and those that phase-lock strongly. PSTHs for units without significant phase-locking vary widely and include patterns resembling those of the mammalian auditory brainstem. Compared with saccular afferents, torus units tend to have lower spontaneous rates, greater sensitivity, and sharper tuning. Unlike saccular afferents, BF is independent of level for most torus units. Some torus units are similar to saccular afferents while others reveal significant transformations of information between the periphery and the midbrain.

Acoustic Stimulation↗
PubMed1993

National status and trends mussel watch program: chlordane-related compounds in Gulf of Mexico oysters, 1986-1990.

The National Oceanic and Atmospheric Administration's National Status and Trends (NS&T) Program has been monitoring the chemical contamination in bivalve tissues from the US coastal waters since 1986. alpha-Chlordane, trans-nonachlor, heptachlor and heptachlor epoxide, components of technical chlordane, are among the chlorinated pesticides measured. The geographical distribution of these chlordane compounds in oyster samples from the US Gulf of Mexico is well-established. For example, highest residue levels, predominantly alpha-chlordane and trans-nonachlor, were encountered in samples collected near highly populated areas in contrast with the concentrations measured in predominantly agricultural areas. Data collected during 5 years of bivalve sampling are used to evaluate temporal trends in residue concentrations at most NS&T sites. Minor decreases can be observed in the concentrations of alpha-chlordane and trans-nonachlor. Heptachlor and its epoxide concentrations, in contrast, have been increasing since 1987.

Journal Article↗
PubMed1993

Source level discrimination by the lateral line system of the mottled sculpin, Cottus bairdi.

A conditioned feeding response of the mottled sculpin was used to measure level discrimination by the lateral line system as a function of source level, frequency, and distance. Level discrimination limens (LDLs) were determined with a 6-mm-diam, sinusoidally vibrating sphere placed in front of the trunk lateral line system at varying distances from the trunk of the fish. LDLs were relatively independent of frequency over most of the detection bandwidth, with mean values ranging from 5-6 dB from 10 to 50 Hz at a fish-to-source distance of 15 mm. The mean LDL at 100 Hz, near the upper end of the frequency range of the lateral line system was 8-9 dB at the same source distance. Mean LDLs at 10 and 20 dB above detection threshold were not significantly different, nor were mean LDLs at distances ranging from 7.5 to 30 mm for a 50-Hz, 10-dB SL source. The level-encoding features of posterior lateral line fibers innervating the trunk were also determined from data previously collected under stimulus conditions nearly identical to those used for behavioral studies. Afferent fibers responded to level increments with increases in both spike rate and phase-locking over most of the conditions used in behavioral experiments. Although it was impossible to eliminate spike rate as a level-encoding mechanism at any stimulus condition, phase-locking appeared to be a strong candidate at low source levels and vibration frequencies.(ABSTRACT TRUNCATED AT 250 WORDS)

Acoustic Stimulation↗
PubMed1993

Sound detection and processing by fish: critical review and major research questions.

The literature on fish hearing has increased significantly since our last critical review in 1973. The purpose of the current paper is to review the more recent literature and to identify those questions that need to be asked to develop a fuller understanding of the auditory capabilities and processing mechanisms of fishes. We conclude that while our understanding of fish hearing has increased substantially in the past years, there are still major gaps in what we know. In particular, the comparative functional literature is extremely limited, and we do not yet know whether different species, and particularly hearing specialists as compared to hearing nonspecialists, have fundamentally different auditory capabilities and mechanisms.

Animals↗
PubMed1992

The effects of temperature change and transient hypoxia on auditory nerve fiber response in the goldfish (Carassius auratus).

Temperature change and hypoxia produce consistent, reversible effects on the response of single auditory nerve fibers in the goldfish. Cooling and hypoxia produce reductions of a cell's spontaneous activity, sensitivity, most excitatory or best frequency (BF) at a given signal level, and overall responsiveness to acoustic stimulation. Warming above ambient temperatures increases a cell's spontaneous activity, sensitivity, BF, and responsiveness. Adaptation, or the tendency for responsiveness to decline with time during a stimulus, increases during hypoxia and cooling, and decreases during warming. The effects of temperature change and hypoxia on a fiber's BF are similar to the effects of overall sound level. Since BF normally increases with sound level, the BF-shift with temperature change and hypoxia can be understood as a change in sensitivity or the overall effectiveness of a stimulus at a given sound level. The effects on neural response of temperature change and hypoxia are probably due in part to changes in the release and replenishment of neurotransmitter at the synapses between hair cells and auditory nerve fibers.

Acoustic Stimulation↗
PubMed1992

Analytic listening by the goldfish.

A stimulus generalization paradigm was used with classical respiratory conditioning to study analytic listening in the goldfish. Animals were first conditioned to suppress respiration upon the presentation of a long-duration complex sound comprised of two sinusoidal components, 166 and 724 Hz. Conditioned animals were then presented with a set of eight novel test tones with frequencies between 95 and 1514 Hz, and including 166 and 724 Hz. Response magnitudes were greatest at the frequencies of the components making up the complex to which the animals were initially conditioned. This is a demonstration that the goldfish had acquired independent information about the frequencies of the individual sinusoidal components making up a complex sound, and thus had listened to the complex analytically. To my knowledge, this is the first demonstration of simultaneous frequency analysis and analytic listening by a nonhuman animal, and suggests that this fundamental aspect of human hearing may be a primitive character shared with the fishes and perhaps with all living vertebrates.

Acoustic Stimulation↗
PubMed1992

Psychometric functions for level discrimination and the effects of signal duration in the goldfish (Carassius auratus): psychophysics and neurophysiology.

Classical conditioning of respiration was used to obtain psychometric functions for pulsed tone level discrimination in the goldfish (Carassius auratus). Conditioned respiratory suppression is a graded response that has some properties of a confidence rating measure. These properties were used to obtain receiver operating characteristics (ROC) and psychometric functions using a blocked method of constant stimuli. Empirical ROCs and neurometric functions were also obtained for single auditory-nerve fibers using spike count as the decision variable in order to evaluate a simple rate code for level discrimination. Psychometric and neurometric functions for level discrimination are similar in showing the same general form (summarized by Weibull functions) that is independent of signal duration. The lower slope of neurometric functions compared with behavioral functions for level discrimination is in accord with similar data on sound detection and vision in nonhuman mammals. Both neural and psychophysical level discrimination thresholds decline with increasing duration (20 to 320 ms), with similar slopes except at short signal durations (20 to 50 ms). At these durations, the animal's use of a channel-selection strategy and neural information following stimulus offset could reduce the difference between neural and psychophysical thresholds. The slopes of the neural and psychophysical duration functions are similar to those for human observers, but the majority of auditory-nerve fibers sampled have lower level discrimination thresholds than the behaving animal. Since human observers perform better than the majority of neurons in level discrimination, well-trained human listeners may be able to select channels with superior information, or to combine information across channels in ways that the goldfish and other animals do not. In general, one is encouraged to believe that neural mechanisms need not be more complex or sensitive than those considered here to account for pure-tone level discrimination in fishes, humans, and other vertebrates.

Animals↗
PubMed1991

Masking and suppression in auditory nerve fibers of the goldfish, Carassius auratus.

The responses of single fibers of the auditory nerve of the goldfish (Carassius auratus) were recorded in response to two tones of different duration (20 ms 'signals' and 200 ms 'maskers') presented simultaneously or non-simultaneously. A single tone may produce excitation, adaptation, and suppression in auditory nerve fibers. For fibers with characteristic frequencies (CF) in the 200 to 400 Hz range, frequencies well above CF tend to produce suppression. If the net response to the masker tone is excitation, an added excitatory signal tone tends to increment the response in a way predictable from the rate-level function for the masker. A masker can attenuate the response to a signal as a result of a compressive and saturating response to the masker, and as a result of a low signal-to-masker ratio. If the net response to a masker tone is suppression, it effectively subtracts from signal excitation, causing 'suppressive masking.' In non-spontaneous fibers, suppression, additive excitatory effects, and adaptation can be revealed by responses to the signal in the absence of spike responses to the masker. In general, the ability of one tone (the masker) to reduce the response to a second tone (the signal) is greater in non-spontaneous fibers than in spontaneous fibers. These results also show that estimates of the frequency selectivity of many goldfish auditory nerve fibers will depend on whether the response of the fiber is defined by excitation, suppression, or both. The response of many fibers with CF in the 200-400 Hz region, as defined by excitation, can be masked or suppressed by a broad range of frequencies covering the effective hearing range of the goldfish.

Acoustic Stimulation↗
PubMed1990

Suppression and excitation in auditory nerve fibers of the goldfish, Carassius auratus.

The suppression of background spike activity in the absence of deliberate acoustic stimulation occurs in fibers of the goldfish saccular nerve tuned in the region of 250 Hz. Suppression is most robust in the frequency range between 450 and 1050 Hz, the range of CF for the mid- and high-frequency saccular fibers. Suppression of background activity tends to occur following the suppressor tone offset ('off-suppression'), even though the spike response during the suppressor is below the background rate. This suggests that the suppressor tone is excitatory at the level of the hair cells and their synapses onto saccular afferents. Tones at the low- frequency edge of the suppression region may show net excitation at low intensity levels, and net suppression at higher levels. This suggests that the spike response observed is the result of the relative strengths of excitatory and suppressive effects which operate simultaneously. The magnitude and frequency of best suppression tends to increase with stimulus intensity. A suppressing tone produces transient excitation at onset. In fibers with high levels of spontaneous activity, a spike response 'rebound' often occurs 20 to 50 ms following the suppressing tone offset. These 'on' and 'off' effects are not due to energy 'splatter' in the stimulus domain. Suppression by tones can also be observed in non-spontaneous fibers when the background spike activity is evoked by noise. In these cases, however, off-suppression following a suppressed response and the 'rebound' seldom occurs. Possible sites of suppression are the hair cells and their synapses, the spike-initiation zones of the saccular afferents, and efferent inhibition. The most likely site seems to be the spike-initiation zones of saccular afferents. An important consequence of suppression for hearing is the sharpening of frequency response areas for low frequency fibers, and the partial preservation of frequency analysis in saccular fibers stimulated well above threshold.

Acoustic Stimulation↗
PubMed1989

Intensity discrimination of pulsed tones by the goldfish (Carassius auratus).

Intensity discrimination thresholds for 500-ms pure-tone bursts were measured as a function of frequency in the goldfish (Carassius auratus) using classical respiratory conditioning. At 55-dB sensation level (SL), thresholds range from 1.44-2.2 dB between 100 and 1600 Hz. There is not important effect of frequency on intensity discrimination. Thresholds at 35-dB SL average 0.7 dB higher than at 55-dB SL. This is a small difference in the context of the threshold variability. In intensity discrimination acuity, the goldfish is quantitatively similar to other vertebrates, including birds and mammals.

Acoustic Stimulation↗
PubMed1989

Frequency discrimination in the goldfish (Carassius auratus): effects of roving intensity, sensation level, and the direction of frequency change.

The ability of goldfish to detect a change in the frequency of 400-Hz pure-tone bursts was studied using classical respiratory conditioning. The frequency discrimination threshold was measured at 15-, 35-, and 55-dB sensation level (SL), under conditions of (1) constant intensity, (2) roving intensity (plus and minus 6-dB burst-to-burst variation in intensity), (3) upward frequency change, and (4) downward frequency change. There was no overall effect of SL on frequency discrimination, but roving the intensity elevated thresholds by about 6 Hz (33%) and increased variability. Upward shifts in frequency elevated thresholds slightly (by 2 Hz or 10%) relative to downward shifts. These relatively small and statistically insignificant effects suggest that earlier measures of frequency discrimination in the goldfish are not due to the detection of simple changes in spike rate within individual peripheral channels.

Acoustic Stimulation↗
PubMed1989

Hot-film anemometry for measuring lateral line stimuli.

A hot-film anemometer system has been calibrated and evaluated for the measurement of sinusoidal water motions used in stimulating the mechanosensory lateral line system of a teleost fish. The response of the anemometer system to water motions created by a vibrating sphere was measured over a wide range of frequencies, intensities, and distances from the sphere. The amplitude response of the system to signals along the axis of sphere vibration was found to be linear over a 50-dB range for frequencies from 10-200 Hz, with the lowest end of the dynamic range (between 10(-8) and 10(-9) m) corresponding to physiological measures of best sensitivity in the lateral line system of the mottled sculpin, Cottus bairdi. The measured attenuation of the signal with distance was also linear over this frequency range out to distances of six times the radius ( = 3 mm) of the sphere and followed the predicted falloff rate for a dipolar source. The linear response of the anemometer system over a wide dynamic range encompassing the detection range of the lateral line system, and the match between predicted and measured motions at varying distances from a dipolar source, indicates that hot-film anemometry is a useful technique for measuring low-level, low-frequency signals likely to stimulate the lateral line system and other hydrodynamic detectors.

Animals↗
PubMed1989

The temporal evolution of masking and frequency selectivity in the goldfish (Carassius auratus).

The temporal evolution of masking and frequency selectivity was studied in the goldfish using classical respiratory conditioning and a tracking psychophysical procedure. The temporal position of a brief tonal signal within a longer duration, tonal masker has little or no effect on signal detectability when the frequency of the masker is less than or equal to that of the signal. For masker frequencies above that of the signal, signal detectability improves as the signal onset is delayed relative to that of the masker. These patterns of tone-on-tone masking are quite similar to those observed for humans. These temporal masking patterns are qualitatively similar in shape to the peristimulus-time histogram profiles of the low-frequency saccular fibers thought to be used in this task. Frequency- and time-dependent changes in signal detectability result in specific changes in the sharpness of psychophysical tuning curves (PTC). In general, PTCs determined for signals occurring at masker onset are the most broadly tuned, and PTCs determined in forward masking are the most sharply tuned. The PTCs for signals temporally centered in the masker are intermediate. These results suggest that temporal tone-on-tone masking patterns and the temporal evolution of psychophysical tuning curves result from the response properties of peripheral auditory-nerve fibers.

Acoustic Stimulation↗
PubMed1988

Comparative psychoacoustics.

Psychophysical data on unspecialized mammals commonly used in auditory research were compiled from the literature, and an attempt was made to compare the hearing capacities of these species with man. Binaural hearing and sound localization were not considered. The most complete psychoacoustic data exist for chinchilla, cat, various primates, and the mouse. The existing data include audiograms, frequency and intensity discrimination thresholds, critical masking ratios, critical bandwidths, temporal summation functions at threshold, psychophysical tuning curves, gap detection thresholds, temporal modulation transfer functions, temporal discriminations, and auditory filter shapes. In general, the qualitative forms of most all psychoacoustic functions for these mammals are similar to those for man, and there is little reason to believe that the mechanisms underlying these capacities are different across mammals. Although the discriminative capacities of humans are generally more acute than those of non-humans, the database on the capacities of non-humans is not yet sufficient for systematic comparisons across species to be made with confidence.

Animals↗