Detection of short pure-tone stimuli in the noctuid ear: what are temporal integration and integration time all about?

1998 ◽  
Vol 183 (5) ◽  
pp. 563-572 ◽  
Author(s):  
J. Tougaard
Keyword(s):  
Pure Tone ◽  
Temporal Integration ◽  
Integration Time

scholarly journals Effect of Interocular Delay on Disparity-Selective V1 Neurons: Relationship to Stereoacuity and the Pulfrich Effect

2005 ◽  
Vol 94 (2) ◽  
pp. 1541-1553 ◽  
Author(s):  
Jenny C. A. Read ◽  
Bruce G. Cumming
Keyword(s):  
Stereo Matching ◽  
Striate Cortex ◽  
Temporal Integration ◽  
Gaussian Function ◽  
Great Majority ◽  
Integration Time ◽  
V1 Neurons ◽  
Temporal Properties ◽  
Pulfrich Effect ◽  
Behaving Monkeys

The temporal properties of disparity-sensitive neurons place important temporal constraints on stereo matching. We examined these constraints by measuring the responses of disparity-selective neurons in striate cortex of awake behaving monkeys to random-dot stereograms that contained interocular delays. Disparity selectivity was gradually abolished by increasing interocular delay (when the delay exceeds the integration time, the inputs from the 2 eyes become uncorrelated). The amplitude of the disparity-selective response was a Gaussian function of interocular delay, with a mean of 16 ms (±5 ms, SD). Psychophysical measures of stereoacuity, in both monkey and human observers, showed a closely similar dependency on time, suggesting that temporal integration in V1 neurons is what determines psychophysical matching constraints over time. There was a slight but consistent asymmetry in the neuronal responses, as if the optimum stimulus is one in which the right stimulus leads by about 4 ms. Because all recordings were made in the left hemisphere, this probably reflects nasotemporal differences in conduction times; psychophysical data are compatible with this interpretation. In only a few neurons (5/72), interocular delay caused a change in the preferred disparity. Such tilted disparity/delay profiles have been invoked previously to explain depth perception in the stroboscopic version of the Pulfrich effect (and other variants). However, the great majority of the neurons did not show tilted disparity/delay profiles. This suggests that either the activity of these neurons is ignored when viewing Pulfrich stimuli, or that current theories relating neuronal properties to perception in the Pulfrich effect need to be reevaluated.

Temporal Integration and the Masking Effect of Spatiotemporal Noise

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 216-216 ◽  
Author(s):  
H T Kukkonen ◽  
J Rovamo
Keyword(s):  
Spectral Density ◽  
Exposure Duration ◽  
Temporal Integration ◽  
Detection Threshold ◽  
Critical Duration ◽  
Masking Effect ◽  
Integration Time ◽  
Detection Thresholds ◽  
Spatial Noise ◽  
Spatiotemporal Noise

In computer-generated spatiotemporal noise every stimulus frame contains a new static noise sample. The spectral density of white spatiotemporal noise is calculated by multiplying the squared rms contrast of noise by the product of the noise check area and the exposure duration of each noise check. When the exposure duration of each noise check is gradually increased, the spectral density of spatiotemporal noise increases, reaching its maximum when noise becomes static. In static spatial noise both stimulus and noise checks have the same duration. The signal-to-noise ratio is known to be constant at detection threshold. Detection thresholds should thus increase in proportion to the spectral density of spatiotemporal noise, which increases with the duration of the noise checks. We measured detection thresholds for stationary cosine gratings embedded in spatiotemporal noise. The exposure duration of the noise checks was increased from one frame duration to the total exposure duration of the stimulus grating. Noise was thus gradually transformed from spatiotemporal to static spatial noise. The contrast energy threshold increased in proportion to the spectral density of spatiotemporal noise up to a noise check duration found to be equal to the integration time for the stimulus grating without noise. After this, energy thresholds remained constant in spite of the increase in the spectral density of spatiotemporal noise. This suggests that the masking effect of spatiotemporal noise increases with the duration of noise checks up to the critical duration marking the saturation of the temporal integration of the signal.

Color-opponent characteristics revealed in temporal integration time

1987 ◽  
Vol 27 (7) ◽  
pp. 1197-1206 ◽  
Author(s):  
Muneo Mitsuboshi ◽  
Yasuhiro Kawabata ◽  
Thomas S. Aiba
Keyword(s):  
Temporal Integration ◽  
Integration Time

Neuroethology of the katydid T-cell. I. Tuning and responses to pure tones

2000 ◽  
Vol 203 (21) ◽  
pp. 3225-3242 ◽  
Author(s):  
P.A. Faure ◽  
R.R. Hoy
Keyword(s):  
T Cell ◽  
Pure Tone ◽  
T Cell Responses ◽  
Integration Time ◽  
High Frequency Ultrasound ◽  
Cell Responses ◽  
T Cell Stimulation ◽  
Auditory Interneuron ◽  
Contralateral Ear ◽  
Ultrasonic Stimulation

The tuning and pure-tone physiology of the T-cell prothoracic auditory interneuron were investigated in the nocturnal katydid Neoconocephalus ensiger. The T-cell is extremely sensitive and broadly tuned, particularly to high-frequency ultrasound (>20 kHz). Adult thresholds were lowest and showed their least variability for frequencies ranging from 25 to 80 kHz. The average best threshold of the T-cell in N. ensiger ranged from 28 to 38 dB SPL and the best frequency from 20 to 27 kHz. In females, the T-cell is slightly more sensitive to the range of frequencies encompassing the spectrum of male song. Tuning of the T-cell in non-volant nymphs was comparable with that of adults, and this precocious ultrasound sensitivity supports the view that it has a role in the detection of terrestrial sources of predaceous ultrasound. In adults, T-cell tuning is narrower than that of the whole auditory (tympanic) organ, but only at audio frequencies. Superthreshold physiological experiments revealed that T-cell responses were ultrasound-biased, with intensity/response functions steeper and spike latencies shorter at 20, 30 and 40 kHz than at 5, 10 and 15 kHz. The same was also true for T-cell stimulation at 90 degrees compared with stimulation at 0 degrees within a frequency, which supports early T-cell research showing that excitation of the contralateral ear inhibits ipsilateral T-cell responses. In a temporal summation experiment, the integration time of the T-cell at 40 kHz (integration time constant tau =6.1 ms) was less than half that measured at 15 kHz (tau =15.0 ms). Moreover, T-cell spiking in response to short-duration pure-tone trains mimicking calling conspecifics (15 kHz) and bat echolocation hunting sequences (40 kHz) revealed that temporal pattern-copying was superior for ultrasonic stimulation. Apparently, T-cell responses are reduced or inhibited by stimulation with audio frequencies, which leads to the prediction that the T-cell will encode conspecific song less well than bat-like frequency-modulated sweeps during acoustic playback. The fact that the T-cell is one of the most sensitive ultrasound neurons in tympanate insects is most consistent with it serving an alarm, warning or escape function in both volant and non-volant katydids (nymphs and adults).

The peripheral auditory characteristics of noctuid moths: responses to the search-phase echolocation calls of bats

1996 ◽  
Vol 199 (4) ◽  
pp. 847-856 ◽  
Author(s):  
D Waters ◽  
G Jones
Keyword(s):  
Short Duration ◽  
High Frequency ◽  
Temporal Structure ◽  
Temporal Integration ◽  
Agrotis Segetum ◽  
Integration Time ◽  
Constant Frequency ◽  
Low Intensity ◽  
Long Duration ◽  
The Central Nervous System

The noctuid moths Agrotis segetum and Noctua pronuba show peak auditory sensitivity between 15 and 25 kHz, and a maximum sensitivity of 35 dB SPL. A. segetum shows a temporal integration time of 69 ms. It is predicted that bats using high-frequency and short-duration calls will be acoustically less apparent to these moths. Short-duration frequency-modulated (FM) calls of Plecotus auritus are not significantly less acoustically apparent than those of other FM bats with slightly longer call durations, based on their combined frequency and temporal structure alone. Long-duration, high-frequency, constant-frequency (CF) calls of Rhinolophus hipposideros at 113 kHz are significantly less apparent than those of the FM bats tested. The predicted low call apparency of the 83 kHz CF calls of R. ferrumequinum appears to be counteracted by their long duration. It is proposed that two separate mechanisms are exploited by bats to reduce their call apparency, low intensity in FM bats and high frequency in CF bats. Within the FM bats tested, shorter-duration calls do not significantly reduce the apparency of the call at the peripheral level, though they may limit the amount of information available to the central nervous system.

Investigation of Temporal Integration by Video Sampling

Perception ◽  
1973 ◽  
Vol 2 (4) ◽  
pp. 441-490 ◽  
Author(s):  
R Williams
Keyword(s):  
Information Integration ◽  
Temporal Integration ◽  
Recognition Task ◽  
Theoretical Models ◽  
Stereoscopic Depth ◽  
Critical Duration ◽  
Integration Time ◽  
Binocular Fusion ◽  
Central Process ◽  
Time Critical

The results from the preliminary set of experiments in which a new video sampling apparatus was used are reported. With the aid of this apparatus experiments were carried out to measure the maximum visual temporal integration time (critical duration) at various background intensities (0·034–34 cd m−2). The aim was to determine to what extent this phenomenon is attributable to either ‘central’ or ‘peripheral’ events. The extended integration period found for the number recognition task is interpreted as evidence of a ‘central’ process; to follow the argument further, an attempt was made to demonstrate information integration using a rotating form in a similar identification–discrimination situation. Monocular, binocular, and dichoptic arrangements were employed, and the amount of dichoptic summation of form information, achieved by both normal and strabismic subjects without stereoscopic depth perception, was used to test two theoretical models of binocular fusion. In addition, stereoscopic depth was generated with uncorrected sampling of the left and right images, which may be due to the action of a ‘fusion hierarchy’. Signal detection theory is suggested as a possible solution to the problem of expectation effects in identification-threshold experiments.

Diphasic and Polyphasic Temporal Modulations Multiply Apparent Spatial Frequency

Perception ◽  
1974 ◽  
Vol 3 (3) ◽  
pp. 323-336 ◽  
Author(s):  
V Virsu ◽  
G Nyman ◽  
P K Lehtiö
Keyword(s):  
Spatial Frequency ◽  
High Frequency ◽  
Light Adaptation ◽  
Second Harmonic ◽  
Temporal Integration ◽  
Low Frequency ◽  
Integration Time ◽  
Sinusoidal Grating ◽  
Spatial Effects ◽  
Spatial Integration

The effects of diphasic and polyphasic flicker on apparent spatial frequency were studied in several experiments through simultaneous spatial-frequency matches. In diphasic flicker the spatial phase of a sinusoidal grating alternated between two values in a counterphase fashion, and in polyphasic flicker the spatial phases of gratings were varied discretely in time in a variable number of steps. Both forms of flicker increased the apparent spatial frequency at low temporal frequencies, in the same manner as low-frequency monophasic flicker has been found to do. At high temporal frequencies, diphasic flicker doubled the apparent spatial frequency, as reported by Kelly (1966). We found that through high-frequency polyphasic flicker the spatial effect that Kelly mentions can be generalised to spatial frequency multiplication: polyphasic flicker produces not only the apparent second harmonic but also the third and the fourth harmonic, depending on the phase parameters. A numerical analysis showed that the spatial high-frequency effects can be explained through temporal integration of nonlinearly filtered input signals if a value of 200 td(1) is assumed for the nonlinearity constant in [Formula: see text] where B( I) is the brightness, I is the retinal illuminance, K is a scale constant, and I½ is the constant of nonlinearity. A minimum value of 60 ms had to be estimated for integration time. An investigation of the integration time with diphasic flicker indicated that spatial integration time decreases when the level of light adaptation increases, and that the integration time for spatial effects is longer than for flicker fusion. The spatial effects of low-frequency and high-frequency flicker differ in so many respects that different neural processes have to be postulated for their explanation.

Recovery of thresholds and temporal integration in adult chickens after high‐level 525‐Hz pure‐tone exposure

1995 ◽  
Vol 97 (2) ◽  
pp. 1150-1164 ◽  
Author(s):  
Samuel S. Saunders ◽  
Richard J. Salvi ◽  
Karen M. Miller
Keyword(s):  
Pure Tone ◽  
Temporal Integration ◽  
High Level

scholarly journals Sex-specific speed–accuracy trade-offs shape neural processing of acoustic signals in a grasshopper

2021 ◽  
Vol 288 (1945) ◽  
pp. 20210005
Author(s):  
Jan Clemens ◽  
Bernhard Ronacher ◽  
Michael S. Reichert
Keyword(s):  
Temporal Integration ◽  
Neural Model ◽  
Integration Time ◽  
Directional Information ◽  
Trade Offs ◽  
Neural Integration ◽  
Chorthippus Biguttulus ◽  
Low Threshold ◽  
Courtship Signals ◽  
Speed Accuracy

Speed–accuracy trade-offs—being fast at the risk of being wrong—are fundamental to many decisions and natural selection is expected to resolve these trade-offs according to the costs and benefits of behaviour. We here test the prediction that females and males should integrate information from courtship signals differently because they experience different pay-offs along the speed–accuracy continuum. We fitted a neural model of decision making (a drift–diffusion model of integration to threshold) to behavioural data from the grasshopper Chorthippus biguttulus to determine the parameters of temporal integration of acoustic directional information used by male grasshoppers to locate receptive females. The model revealed that males had a low threshold for initiating a turning response, yet a large integration time constant enabled them to continue to gather information when cues were weak. This contrasts with parameters estimated for females of the same species when evaluating potential mates, in which response thresholds were much higher and behaviour was strongly influenced by unattractive stimuli. Our results reveal differences in neural integration consistent with the sex-specific costs of mate search: males often face competition and need to be fast, while females often pay high error costs and need to be deliberate.

Temporal Integration: I. Clinical Implications of a Laboratory Study. II. Additional Data from Hearing-Impaired Subjects

1971 ◽  
Vol 36 (2) ◽  
pp. 213-224 ◽  
Author(s):  
Roy W. Gengel ◽  
Charles S. Watson
Keyword(s):  
Hearing Impairment ◽  
Additional Data ◽  
Temporal Integration ◽  
Measurement Procedure ◽  
Repeated Measurements ◽  
Sensorineural Hearing ◽  
Integration Time ◽  
Sensorineural Hearing Impairment ◽  
Single Standard ◽  
Integration Data

The two purposes of this report are to discuss three problems that clinicians should consider when they use temporal integration data for diagnostic purposes and to provide additional data on temporal integration in persons with sensorineural hearing impairment. The first problem which must be considered stems from evidence that, for persons with normal sensitivity as well as persons with sensorineural hearing impairment, integration time is dependent on frequency. Therefore, before making inferences about atypical temporal integration, norms should be established for each test frequency. The second problem stems from evidence that an individual can show considerable variability when repeated measurements of temporal integration are made. Therefore, until a highly reliable measurement procedure is found, several determinations of the temporal integration function should be made. The third problem stems from evidence that integration time can differ when different psychophysical procedures are used. These differences, due to method of measurement, lead to very different interpretations of temporal integration data. Therefore, it is suggested that a single, standard clinical procedure for measuring temporal integration be developed. The second half of the report gives temporal integration data from eight persons with sensorineural hearing-impairment who show a wide variety of audiometric configurations.

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