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Results for “Pitch Discrimination”

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At least 415 records · Page 23Linked to original sources
PubMed1984

Discrimination of fundamental frequency of synthesized vowel sounds in a noise background.

An experiment was carried out, investigating the relationship between the just noticeable difference of fundamental frequency (jndfo) of three stationary synthesized vowel sounds in noise and the signal-to-noise ratio. To this end the S/N ratios were measured at which listeners could just discriminate a series of changes in fo in the range from 10% to 0.5%. Similar measurements were obtained for pulse trains and for pure tones as a reference for the results. A measure of S/N ratio based on an approximation of the critical bandwidth appeared to provide a fairly good predictor of the masked threshold of each signal, measured in a second experiment. Using this measure, it was found that a given change in the fundamental of a pulse train could be discriminated at a lower S/N ratio than in a pure tone with a frequency equal to that fundamental. The results for the vowel sounds were found to be in between those for a low-frequency pure tone and those for a pulse train. Owing to the signal-generation method (viz., changing fo by changing the sampling frequency), three cues could in principle be used to discriminate a change in the fundamental of a vowel: A change in the residue pitch, a change in the pitch of a single prominent harmonic, or a change in the spectral envelope of the signal. It can be inferred from the results that the subjects used that particular cue which yielded best performance. Which cue was optimal depended not only on the vowel but also on fo and on the presented change in fo.(ABSTRACT TRUNCATED AT 250 WORDS)

Auditory Threshold↗
PubMed1974

Stimulus control of heart rate by auditory frequency and auditory pattern in pigeons.

A new method was used to investigate auditory discrimination in pigeons. Basically, the method involves the repeated presentation of one stimulus preceding the single presentation of a different stimulus that is followed by shock. Stimulus control is assessed by the increase in heart rate that accompanies the presentation of the second stimulus. In Experiment 1, the efficiency of the method was explored by determining the frequency difference thresholds of pigeons at 500, 1000, 2000, and 4000 Hz. Weber fractions comparable to those reported in an earlier study using the conditioned suppression method were obtained. Experiment 2 demonstrated that, contrary to results of earlier studies, auditory temporal patterns can exercise differential stimulus control in pigeons. One stimulus consisted of the presentation (once per second) of a 1000-Hz pure tone of 150 msec duration followed by a 2000-Hz pure tone of equal duration; the other was the same except for the reversed order of the frequency components. Results indicated that the frequency pattern and not the loudness pattern of the stimuli was the cue controlling heart-rate changes.

Acoustic Stimulation↗
PubMed1994

Analysis of eyeblink activity during discriminative tasks.

To evaluate the blinking pattern during and after cognitive processing, 10 subjects' eyeblinks were recorded by a videotape recording camera placed 100 cm from the subjects' side. The subjects' task was to discriminate two kinds of auditory tones presented serially and to discriminate two kinds of visual stimuli presented serially. Treatments were composed of the baseline condition preexperiment, the visual task with no discrimination, the visual discriminative task, the auditory task with no discrimination, and the auditory discriminative task. The blink rate in each treatment, the temporal distribution of blinks poststimulus, and the blink waveform were evaluated. Although blinks were not inhibited during tasks, frequent blinks after tasks were observed in both modalities. Blinks concentrated between 300 msec. and 800 msec. after the discriminated stimulus and formulated the blink-rate peak. The closing velocity of lid in the blink rate peak was lower after auditory stimulus. Moreover, the lid's opening velocity after the auditory discrimination was higher. These results indicated that the eyelid closed slowly and opened quickly after the auditory discriminative stimulus.

Adolescent↗
PubMed1990

[Sex differences in memory performance for odors, tone sequences and colors].

Sense of olfaction would seem to be of little importance for human behavior. However, a closer look at this from the psychological point of view reveals many interesting aspects, such as sex differences in olfactory perception, that are of interest to differential psychology. The present study deals with sex differences in the memory for odors; we assume that women will do better here than men while other memory tasks involving acoustical and optical stimuli will show no such differences. Sixty women and 40 men were examined. On the first day, they had to retain 10 odors, 10 random-generated tone-sequences, and 10 colors. On the second day, 20 such stimuli for each memory task were presented, and the subjects had to remember and to tell which were known and which of them were unknown stimuli to them. A significant advantage in the olfaction memory task was found for women, while acoustical and optical memory scores showed no such differences. This expected finding is discussed in two ways. First, the female advantage might result from phylogenetic sources. Second, it might arise because women in general more often than men seem to deal with olfactory cues, so that they might simply have more experience and therefore the greater chance to score higher in an odor memory task.

Adult↗
PubMedDate not supplied

[Participation of the substantia innominata in differential inhibition in the cat].

Elaboration of differentiation, its disturbance resulting from bilateral lesion of the substantia innominata and its subsequent restoration was studied in cats. Ablation of the substantia innominata was accompanied by disturbances of the internal inhibition. The initial level, that before the operation, was not obtained even after a long training. It is suggested that substantia innominata modulates cortical activity and its ablation prolongs the afferent synthesis.

Animals↗
PubMedDate not supplied

[Correlations among cortical potentials in the dog during the elaboration of motor alimentary conditioned reflexes].

Background electrocortical activity in a frequency band of 1-100 Hz of dogs with electrodes implanted in different neocortical areas was studied before and after elaboration of motor (lever pressing) alimentary conditioned responses. Conditioning led to a significant change of the distribution histograms of cross-correlation coefficients (CC) between the cortical potentials, i. e. the dispersion of CC values decreased and the level of correlation changed as well. In more tranquil animals (with lower CC values before conditioning) the level of correlation significantly increased, in excitable ones (with higher CC values before conditioning) it decreased. CC distributions after the conditioned response elaboration became similar in both cases apparently indicating the formation of a uniform state characteristic for the type of a conditioned response under study.

Animals↗
PubMedDate not supplied

[Effect of destruction of the septum and hippocampus on the shuttle-box avoidance conditioning of the rat].

Total destruction of the septum, the dorsal hippocampus (DH), or the lesion of the DH combined with that of the medial septal nucleus in rats was shown to facilitate elaboration of conditioned avoidance responses in a shuttle-box due to an increase of general excitability of the animals, and to cause significant impairment of internal inhibition formation. Lesions of the medial or the lateral septal nuclei as well as a combined lesion of the DH and the lateral septal nucleus had no significant effect on conditioning and internal inhibition elaboration. Therefore the septo-hippocampal connections had different functional directions during active defensive behaviour.

Animals↗
PubMed1985

Perceptual learning in frequency discrimination.

This study was concerned with the effects of training on the frequency discrimination ability of human listeners. Frequency discrimination at 200 Hz was tested before and after training. Four groups of listeners received training in four different frequency regions, 200, 360, 2500, and 6000 Hz. It was found that training at 200, 360, and 2500 Hz all provided comparable improvement in discrimination performance at 200 Hz whereas training at 6000 Hz provided less improvement. This result is consistent with the idea that frequency discrimination and pitch perception are mediated by different processes at high (greater than 5000 Hz) and low (less than 5000 Hz) frequencies.

Adult↗
PubMed2005

Generalization of frequency discrimination learning across frequencies and ears: implications for underlying neural mechanisms in humans.

Frequency discrimination thresholds (FDTs) at 750, 1500, 3000, and 6000 Hz were measured in 32 normal-hearing listeners before and after each listener practiced the task for 12 h at one of the above frequencies using a single ear. Marked improvements in thresholds taking place over several hours were observed during the frequency- and ear-specific training period. Comparisons between pre- and posttraining thresholds showed large improvements at the trained frequency, but also at other frequencies. The improvements were initially slightly-but significantly-larger at the trained frequency than at untrained frequencies. However, this trained-frequency advantage disappeared rapidly during the course of the two-hour multifrequency posttraining session, suggesting rapid relearning or learning generalization across frequencies. In contrast, no significant ear specificity was found, not even at early stages of the posttraining session. These findings add to earlier results suggesting that, in humans, frequency discrimination learning is only weakly frequency-specific, and they reveal that a complete generalization across frequencies can occur rapidly with little retraining at the initially untrained frequencies. Implications regarding underlying mechanisms are discussed.

Adult↗