Critical fusion frequency as a function of stimulus intensity: and wavelength composition

Six Ss made judgments of equal loudness by adjusting the intensity of comparison tones of 10 different frequencies. The comparison tones were presented diotically alternately with standaxd tones. Each standard tone remained fixed at one frequency (125, 1,000, or 8,000 Hz) and one intensity (10, 20, 40, or 70 dB sensation level)while collecting the data for any single equal-loudness contour. In this manner, families of equal-loudness contours were generated for each of the three standard frequencies. The contours for the 1,000-Hz standard were compared with those in the literature. The families of contours for the 125- and 8,000-Hz standards, determined by the same algorithm, differed in the spacing of the contours from the 1,000-Hz standard family as well as from each other. Implications for the reflexive, symmetric, and transitive properties of the equal-loudness relation axe discussed.     

Masking-level differences in older adults: The effect of the level of the masking noise

In Experiment 1, masking-level differences (MLDs) for a 500-Hz tone at five masker levels were obtained from younger and older adults. For both age groups, there were no reliable increases in MLD once the spectrum level of the masker exceeded 27 dB SPL. MLDs were larger for younger than for older adults over the range of masker levels tested. In Experiment 2, the levels of both the signal and the masker in one ear were attenuated by either 15 or 30 dB relative to their level in the other ear, which was fixed at a spectrum level of 47 dB SPL. MLDs for both age groups declined with increasing IAA and age-related differences were observed in all conditions. The findings of these experiments indicate that (1) age-related differences in MLDs exist even when the level of the masker is sufficiently high that older adults achieve their plateau performance, and (2) older listeners are not disadvantaged more than younger listeners by interaural differences in the level of the input.     

Appetitive differential conditioning of the rabbit’s jaw movement response

Two experiments examined appetitive differential conditioning of the rabbit’s jaw movement response (JMR) in a two-phase procedure. The first phase entailed reinforced training with one conditioned stimulus (CS+), and the second phase involved intermixed presentations of CS+ and an unreinforced stimulus (CS?). In Experiment 1, CS+ was a 600-Hz tone, and CS-was either a 660-,1,000-, or 2,100-Hz tone. In Experiment 2, the magnitude of the water unconditioned stimulus (US) paired with CS+ was either 1, 3, or 9 ml. The experiments revealed that 1) the level of responding to CS-rose for several days and then declined over the remainder of training; 2) the physical similarity between CS+ and CS?directly affected the level of responding to CS?but had no discernable effect on the level of responding to CS+ ; and 3) US magnitude positively affected the level of responding to CS + and, to a lesser extent, CS?. The results are discussed in terms of their implications for Spence’s gradient interaction theory and Pavlov’s external inhibition hypothesis.     

Stimulus intensity,catch trial effects,and the speed-accuracy tradeoff in reaction time: A variable criterion theory interptation

Ss responded to a 1,000-Hz tone of 50, 80, or 100 dB. Catch trial conditions were none, blank trials, a red light, a noise, and an 1,800-Hz tone. Auditory catch signals were of the same intensities. RT distributions in the first three conditions were well described by a family of exponential growth functions dependent upon stimulus intensity and by the parameters of normal criterion distributions dependent upon catch trial conditions and between-session variability. Performance in the auditory catch trial conditions was not dependent upon the same set of sensory growth functions. Performance in these conditions was described by a two-dimensional analysis of information transmitted as a function of time and interpreted in terms of variable criterion theory. The speed-accuracy tradeoff in this situation appears to depend upon differential rates of growth of intensity and associative information and the criterion used in responding to this information.     

Body sway during long-term standing and as affected by pure tones

Sixty students, male and female, were used as Ss to test the effect of a 1, 000-Hz, 5-sec tone at 0, 70, and 90 dB, on standing sway. In general, antero-posterior sway was greater than lateral, and males swayed more than females in both directions. In addition, males increased their sway in time, whereas females did not. Only lateral sway in the 5-sec interval after the presentation of the tone increased, and only after 10, 15, and 20 min of standing, with a maximum at 15 min. Amplitude of lateral sway appeared independent of bodily characteristics, and is suggested as being more useful for comparing Ss than is antero-posterior sway.     

Factors producing and factors not producing time errors: An experiment with loudness comparisons

Pairs of 1-sec, 1,000-Hz tones, with interstimulus intervals of 1.5 sec, were judged by 60 subjects in categories of “louder,” “softer,” and “equal.” The judgments referred to the first tone in the pair for half of the subjects and to the second tone for the other half. Perceived loudness differences were scaled by a Thurstonian method. The SPL of the standard tone alternated between 50 and 70 dB in one experimental series and between 30 and 50 dB in the other. Time errors (TEs) were consistently positive (first tone overestimated relative to second) at the lower SPL and negative at the higher SPL. This “classical” effect of stimulus level on TE was thus shown to depend upon the relative, rather than the absolute, level of stimulation. The judgment mode was of very little consequence, which strongly contradicts TE theories that emphasize response-bias effects. The quantitative results are interpreted in terms of a general successive-comparison model employing the concepts of adaptation and differential weighting of sensation magnitudes.     

Heart-rate responses of infant rats and guinea pigs to stimulus onset and offset: tests of the generality of a bidirectional effect

To test the generality, across modality and across species, of a bidirectional effect of photic stimulation in infant rats found in previous experiments, two experiments examined the effects on heart rate (HR) of onset and offset of auditory stimulation in rats and of photic stimulation in guinea pigs. Experiment 1 demonstrated a unidirectional, decelerative response in rats 17 and 21 days of age to the onset and offset of a 1-kHz tone, at both low (80 dB) and high (100 dB) intensity levels and at 14 days to the onset of the high-intensity tone. Experiment 2 demonstrated that infant guinea pigs, which unlike infant rats are precocial and not nocturnal, responded to the offset but not to the onset of light, and that this response was decelerative. These results indicated a lack of generality of the bidirectional HR effect, and were discussed in terms of the orienting/defensive reflex distinction.     

Sources of auditory masking in infants: distraction effects.

Previous work has demonstrated that infants' thresholds for a pure tone are elevated by a masker more than would be predicted from their critical bandwidths. The present studies explored the nature of this additional masking. In Experiment 1, detection thresholds of 6-month-old infants and of adults for a 1-kHz tone were estimated under three conditions: in quiet, in the presence of a 4- to 10-kHz bandpass noise at 40 dB SPL, and in the presence of the same noise at 50 dB SPL. The noise was gated on at the beginning of each trial. Adult thresholds were the same in all three conditions, indicating that little or no sensory masking took place in the presence of the noise. Infant thresholds were about 10 dB higher in the presence of the noise. We term this effect distraction masking. In Experiment 2, the effect of gating the noise on at trial onset was examined. Thresholds for the same tone were estimated in quiet and in the presence of the band-pass noise at 40 dB SPL, but the noise was presented continuously during the session. Under these conditions, distraction masking was still observed for infants. These findings suggest that a masker can have nonsensory effects on infants' performance in a psychoacoustic task.     

Sources of auditory masking in infants: Distraction effects

Previous work has demonstrated that infants’ thresholds for a pure tone are elevated by a masker more than would be predicted from their critical bandwidths. The present studies explored the nature of this additional masking. In Experiment 1, detection thresholds of 6-month-old infants and of adults for a 1-kHz tone were estimated under three conditions: in quiet, in the presence of a 4- to 10-kHz bandpa] noise at 40 dB SPL, and in the presence of the same noise at 50 dB SPL. The noise was gated on at the beginning of each trial. Adult thresholds were the same in all three conditions, indicating that little or no sensory masking took place in the presence of the noise. Infant thresholds were about 10 dB higher in the presence of the noise. We term this effectdistraction masking. In Experiment 2, the effect of gating the noise on at trial onset was examined. Thresholds for the same tone were estimated in quiet and in the presence of the bandpass noise at 40 dB SPL, but the noise was presented continuously during the session. Under these conditions, distraction masking was still observed for infants. These findings suggest that a masker can have nonsensory effects on infants’ performance in a psychoacoustic task.     

Reliability and magnitude of auditory laterality effects: the influence of attention

Three experiments investigated the effect of attention on the reliability and magnitude of laterality effects in a dichotic listening task. In Experiment 1, 40 undergraduate students were randomly assigned to either a free-recall or focused-attention condition. In Experiment 2, 40 undergraduate students completed a dichotic listening task with exogenous cueing. They were randomly assigned to either a 150-ms stimulus onset asynchrony (SOA) or a 450-ms SOA condition. In Experiment 3, 20 participants completed a task where the SOA for the exogenous cue was randomized on a trial to trial basis. Results indicated that focused attention increased the magnitude of the laterality effect. Contrary to predictions, this finding was not due to reduced variability in the focused-attention task compared to the free-recall task. In addition, a cueing tone was only effective at directing attention in Experiment 3. Specifically, a significant right ear advantage observed at the 150-ms SOA was reduced at the 450-ms SOA. It appears that, in Experiment 3, the tone was effective at controlling attention because it reduced the systematic bias that has been suggested to account for the laterality effects observed in dichotic tasks.     

Long latency auditory evoked potentials

Experiment 1 elicited the P1, N1, P2, and N2 components of the long latency auditory evoked potential (AEP) using a 1000 Hz tone presented at 30, 50, or 70 dB SPL and 1-, 3-, or 5- second inter-stimulus intervals to assess the relative effects of the combination of these variables on component amplitude and latency. Four blocks of 16 tone presentations each were recorded from each subject to determine if changes in the AEP would occur because of short-term habituation. Both stimulus factors interacted significantly in a systematic fashion for the amplitude measures, with increases in latency also associated with increases in intensity and inter-stimulus interval. Only minor changes across the four trial blocks for either the amplitude or latency measures were observed over the various stimulus presentation conditions. Experiment 2 employed the same tone stimulus presented at 50 dB SPL and a 3-second inter-stimulus interval. Eight blocks of 64 trials were recorded from each subject on each day for four days to investigate long-term habituation effects. No substantial changes in any of the component amplitudes or latencies were obtained across the 32 trial blocks. It was concluded that intensity and inter-stimulus interval interact to determine AEP amplitude as well as latency values and that the constituent components do not change appreciably with repeated stimulus presentations, even after several days.     

Effects of noise on pure-tone thresholds in blackbirds (Agelaius phoeniceus and Molothrus ater) and pigeons (Columba livia)

Blackbirds and pigeons were trained to detect tones in quiet and in broadband noise by using positive-reinforcement techniques. In Experiment 1, thresholds in noise were obtained in blackbirds as a function of both tone frequency and noise intensity for a pulsed noise masker (noise gated on and off with tone). For blackbirds, critical ratios (the ratio of the power of the just-detectable tone in noise to the power of the noise masker) obtained in pulsed noise showed no consistent relation to tone frequency. For pigeons, on the other hand, critical ratios obtained in continuous noise increased by about 3 dB/octave across their range of hearing, being similar to known critical ratio functions for cats and humans. In Experiment 2, critical ratios in blackbirds obtained with both continuous noise and pulsed noise were compared. Blackbird critical ratios were more stable in continuous noise and averaged 4 dB lower than critical ratios in pulsed noise. The blackbird critical ratio function obtained with continuous noise was similar to the known critical ratio function of another avian species, the parakeet. Thus, small birds appear to have atypical critical ratio functions, compared with pigeons and other vertebrates.     

The ontogeny of auditory frequency generalization in the chicken.

To determine if there is an ontogenetic change in stimulus coding, chickens between the day of hatching and 9-10 days old were tested using a habituation-generalization paradigm. Experiment 1 indicated that 1 day-old and 3--4-day-old chicks show similar habituation of an eye-opening response to auditory stimuli in the 800--1,200-Hz range. In Experiment 2 the eye-opening response to a 1,000-Hz stimulus was habituated and then immediately tested using stimuli which varied between 800 and 1,200 Hz. Each age-group (1 day, 3--4 days, and 9--10 days) showed a symmetrical stimulus generalization gradient around the 1,000-Hz stimulus and the 1-day-old chicks displayed a reliably flatter gradient than either of the older groups, which did not differ. In a third experiment, the position of the gradients relative to the baseline was shifted without altering the relative shapes. These results allow general arousal, general auditory responsiveness, overall error rate, and metric characteristics of the independent and dependent variables to be eliminated as possible sources of the age differences in gradient shape. The changes in stimulus generalization, therefore, support the view that during normal development there is a sharpening of perceptual coding processes.     

Preference for tones as a function of frequency (hertz) and intensity (decibels)

An extension of the Wundt hypothesis concerning stimulus intensity and hedonic tone leads to the prediction that Ss prefer tones of intermediate frequency (hertz) and of intermediate intensity (decibels). In Experiment 1, tones varying from 60 to 5000 Hz were presented in a paired comparison procedure, and, as predicted, Ss′ preference was an inverted-U-shaped function of frequency, with the most preferred tones in the range of 400–750 Hz. In Experiment 2, tones varying in intensity from 40 to 90 dB were also presented in a paired comparison procedure, and again the predicted inverted-U-shaped preference function was found, with 50 dB as the preferred intensity. Related research and some unexpected findings are discussed.     

Ready-signal effects as a function of experimental design in simple reaction time

In the between-S design, 20 Ss had a visual ready signal presented on each trial; for another 20 Ss, the ready signal was always absent. The within-S design consisted of 40 Ss that experienced both ready-signal conditions in semirandom order. Two intensities of a 1,000-Hz tone were used as the response signals Ready-signal manipulation had pronounced effects under the within-S but not the between-S design irrespective of response-signal intensity     

The slippery context effect in psychophysics: Intensive,extensive, and qualitative continua

When subjects gave magnitude estimates of 500- and 2500-Hz tones at various SPLs, they judged a 500-Hz tone of 60 dB to be as loud as a 2500-Hz tone of 57 dB in one context (low SPLs at 500 Hz, high SPLs at 2500 Hz), but as loud as a 2500-Hz tone at 40 dB in another context (high SPLs at 500 Hz, low at 2500 Hz) (Marks, 1988). Such shifts in matches derived from judgments of multi-dimensionally varying stimuli are termedslippery context effects. The present set of seven experiments showed that slippery effects were absent from judgments of pitch of tones at different loudnesses, duration of tones at different pitches, and length of lines at different colors, though a small effect emerged in judgments of duration of tones and lights. Slippery context effects were substantial when subjects gave magnitude estimates of loudness of 500- and 2500-Hz tones under conditions in which the pitch at each trial either was cued visually beforehand or could be known through the regular stimulus sequence, and with instructions to make absolute magnitude estimates. The results are consistent with the view that slippery context effects occur automatically and “preattentively.”     

声调在汉语音节感知中的作用

探讨超音段(如声调)与音段信息的共同作用机制, 对口语词汇识别研究具有重要的理论意义。有研究探讨了声调在口语词汇语义通达阶段的作用, 但在相对早期的音节感知阶段, 声调与声母、韵母的共同作用机制还缺乏系统的认识。本研究采用oddball实验范式, 通过两个行为实验考察了声调在汉语音节感知中的作用。实验1发现检测声调和声母变化的时间没有差异, 均比检测韵母变化的时间长, 表明在汉语音节感知中对声调的敏感性不及韵母。实验2发现声母和韵母的组合并没有明显优于对韵母的觉察, 但声调与声母或韵母的同时变化都促进了被试对偏差刺激的觉察, 表明声调通过与声母、韵母的结合来共同影响汉语音节的感知加工。研究结果在认知行为层面为声调在音节感知中的作用机制提供了直接的实验证据, 为进一步探讨超音段与音段信息共同作用的认知神经机制提供了基础。     

The effect of exogenous spatial attention on auditory information processing

This study investigated the effect of exogenous spatial attention on auditory information processing. In Experiments 1, 2 and 3, temporal order judgment tasks were performed to examine the effect. In Experiment 1 and 2, a cue tone was presented to either the left or right ear, followed by sequential presentation of two target tones. The subjects judged the order of presentation of the target tones. The results showed that subjects heard both tones simultaneously when the target tone, which was presented on the same side as the cue tone, was presented after the target tone on the opposite side. This indicates that spatial exogenous attention was aroused by the cue tone, and facilitated subsequent auditory information processing. Experiment 3 examined whether both cue position and frequency influence the resulting information processing. The same effect of spatial attention was observed, but the effect of attention to a certain frequency was only partially observed. In Experiment 4, a tone fusion judgment task was performed to examine whether the effect of spatial attention occurred in the initial stages of hearing. The result suggests that the effect occurred in the later stages of hearing.     

The slippery context effect in psychophysics: intensive, extensive, and qualitative continua.

When subjects gave magnitude estimates of 500- and 2500-Hz tones at various SPLs, they judged a 500-Hz tone of 60 dB to be as loud as a 2500-Hz tone of 57 dB in one context (low SPLs at 500 Hz, high SPLs at 2500 Hz), but as loud as a 2500-Hz tone at 40 dB in another context (high SPLs at 500 Hz, low at 2500 Hz) (Marks, 1988). Such shifts in matches derived from judgments of multidimensionally varying stimuli are termed slippery context effects. The present set of seven experiments showed that slippery effects were absent from judgments of pitch of tones at different loudnesses, duration of tones at different pitches, and length of lines at different colors, though a small effect emerged in judgments of duration of tones and lights. Slippery context effects were substantial when subjects gave magnitude estimates of loudness of 500- and 2500-Hz tones under conditions in which the pitch at each trial either was cued visually beforehand or could be known through the regular stimulus sequence, and with instructions to make absolute magnitude estimates. The results are consistent with the view that slippery context effects occur automatically and "preattentively."     

Directed attention influences the modification of startle reflex probability

The present study was designed to investigate the effect of directed attention on elicitation and modification of the startle reflex. 30 adult human subjects received 90 dB(A) broadband noise startle stimuli either alone or preceded by a 60 dB(A) prepulse (either 2000-Hz tone, 1000-Hz tone, or broadband noise). Subjects were instructed to attend to one of the three prepulses during half the trials and to ignore all stimuli during the rest of the trials. The probability of responding while attending to a prepulse was significantly lower than the probability of responding while ignoring the prepulses. Responding to the prepulses was also more probable while subjects were attending to the prepulses, and these effects were more pronounced for tone than for noise prepulses. These results suggest that directed attention can influence the probability of the startle reflex without influencing startle amplitude or latency.