The masking of octave-band noise by broad-spectrum noise: A comparison of infant and adult thresholds

Localization responses to a 4,000-Hz octave-band noise in a background of broad-spectrum noise were obtained from infants, 6, 12, 18, and 24 months of age, and adults. A two-alternative, forced-choice procedure was used to determine thresholds at each of two levels of masking noise, 42 and 60 dBC. Adults were also tested for their localization of pure tones in noise and their detection of octave-band noises with the more traditional two-interval, forced-choice task. Increasing the masking noise from 42 to 60 dBC resulted in comparable threshold shifts for all age groups. However, infant thresholds were 16–25 dB higher than those obtained for adults. The theoretical implications of these findings are discussed.     

On the physiological basis of masking with dotted visual noise1

In this paper, consideration is given to the physiological foundations of visual masking with successive stimuli. Three experiments are performed with dot patterns. The results indicate that none of the classic characteristics of lateral inhibitory interaction are obtained with this type of stimulus material. A rather informal demonstration is then described that suggests further that lateral inhibitory interaction may also not be a satisfactory explanation of metacontrast and other kinds of masking that use continuous figures.     

Backward masking of lateralized faces by noise, pattern, and spatial frequency

Experiments 1 and 2 measured the critical interstimulus interval at which a face presented to the right or left visual field escaped a trailing noise, pattern, or spatial-frequency mask. The function relating target duration to critical ISI was multiplicative in the noise and spatial-frequency condition, but additive at longer durations in the pattern mask condition. An advantage of about 8 msec for the left visual field and 2 msec for the right field was found in the pattern and spatial-frequency masking condition, respectively. No consistent visual field differences were found in the noise mask condition. Taken together, these results suggest that hemispheric difference in face recognition are either absent or inconsistent at early, peripheral, energy-sensitive stages of processing, but emerge strongly at higher order central stages. The results also suggest that the left and right hemispheres are not differentially sensitive to the output of high- and low-spatial-frequency channels, respectively. If it is assumed that the central face processor is functionally localized to the right hemisphere, one can infer from these results that interhemispheric transmission time is not greater than 8 msec, and the output of sensory analysis and/or relational features are transferred across the interhemispheric commissures.     

Detection and recognition of intensity changes in tone and noise: The detection-recognition disparity

Recognition of increments vs decrements in auditory intensity improves with signal duration, relative to detection of increments and decrements. This effect obtains whether the background stimulus is a tone, noise, or a tone with noise masker, and is largely uninfluenced by the rise time of the signals. These data are inconsistent with detection models in which the O makes only one sensory observation during each observation interval, but can be described in terms of a neural timing model in which transients play a critical role.     

Auditory temporal summation in infants and adults: Effects of stimulus bandwidth and masking noise

A visually reinforced operant procedure was employed to determine the behavioral thresholds of 6- to 7-month-old infants and adults for stimuli of various bandwidths and durations. Experiment 1 compared absolute thresholds for broadband and 1/3-octavefiltered clicks and 300-msec noise bursts. For adult subjects, the difference in threshold for clicks and noise bursts was -quite comparable in the two bandwidth conditions, but infants’ click-noise threshold differences were significantly larger for broadband than for 1/3-octave stimuli. In Experiment 2, 2-point threshold-duration functions were compared for 4-kHz tones and octave-band noise bursts presented in backgrounds of quiet and continuous noise. Infants’ threshold-duration function for octave-band noise bursts was significantly steeper than the comparable adult function in quiet, but not in masking noise. These results suggest that young infants may have particular difficulty detecting low intensity broadband sounds when durations are very short.     

On the relations between crowding and visual masking

To study the question of which processes contribute to crowding and whether these are comparable to those of visual temporal masking, we varied the stimulus onset asynchrony (SOA) between target and flankers in a crowding setting. Monotonically increasing Type A masking functions observedfor small spacings and large eccentricities indicate that the integration of information from target and flankers underlies crowding. Decreasing masking functions obtained for large spacings and small eccentricities relate processes of crowding to those contributing to Type B masking. In addition, Type B masking was more frequent with letter-like nonletter flankers than with letter flankers, suggesting that Type B masking, just like crowding over large areas, is due to higher level interactions. The rapid decrease of the effects of interletter spacing and eccentricity with increasing SOA indicates that positional information is transient.     

No time-stretching illusion when a tone is followed by a noise

A sine tone is perceived as longer when it is preceded by a more intense noise than when presented in isolation. This is the time-stretching illusion. We conducted an experiment where the method of constant stimuli was used to examine whether a tone would also be stretched when it was followed by a noise. The duration of a tone was overestimated when it was preceded by a noise, but not when followed by a noise or when located between two consecutive noises. Moreover, the increasing of the noise intensity (from ?6 to +6 dB) relative to the tone intensity resulted in larger overestimations, but only in the condition where a tone was preceded by a noise. In brief, the duration of a tone is stretched when this tone is preceded by a noise and if this tone is not followed by a noise.     

Effects of auditory masking by white noise on primary stressing during spontaneous speech

6 adult subjects (3 men, 3 women) produced highly similar spontaneous speech utterances in quiet and with 90-dB SPL white noise. The frequency of occurrence of perceptual judgments of primary stressing in an utterance was not affected by the masking noise. This finding supplements our previous report that variability for stress production of fundamental frequency (fo) during spontaneous speech was preserved under short-term auditory disruption. Also, it adds further support to the contention that fo is under open-loop regulation.     

On the Asymmetry between Twin Earth and Inverted Earth

A crucial disanalogy between Twin Earth and Inverted Earth undermines qualia‐internalism. A recent transplant to Inverted Earth has been equipped with color‐inverting contact lenses, so that she is unable to see the colors of objects whereas a recent transplant to Twin Earth can see twater. It is implausible to think that time alone could rectify this perceptual shortcoming – that the passage of time could alter the contents of her visual perceptions or the meaning of her color terms. Thus, the thought experiment does not refute the close tie between phenomenology and representation in the case of color.     

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.     

On the relation between metacontrast masking and suppression of visible persistence

Does the introduction of additional contours in a display sequence (an operation known to reduce the strength of suppression in metacontrast) also reduce suppression of visible persistence? In three experiments, duration of visible persistence was estimated by a method in which successful performance depends on the temporal integration of a pattern whose elements are displayed in two successive frames. In this procedure, the arrival of the trailing frame is known to exert a suppressive influence on the visible persistence of the leading frame. Embedding the elements of the leading frame within additional contours (a line grid) reduced the degree of suppression exerted by the trailing frame. This did not occur when the grid was part of the trailing display. We conclude that suppression of visible persistence and metacontrast masking belong to the same class of events.     

The relationship between skin tone dissatisfaction and sun tanning behaviour

Understanding the factors that contribute to sun exposure is vital for skin cancer prevention. The present study aimed to examine the utility of a new measure for cancer prevention research, the Skin Tone Rating Scale. Australian undergraduate women (N = 156) completed an online questionnaire measuring skin tone dissatisfaction, peer and media norms surrounding tanning, internalisation of a tanned ideal, appearance reasons for tanning, and self‐reported tanning behaviour. The two‐item Skin Tone Rating Scale provided a short and easy‐to‐administer measure of skin tone dissatisfaction that correlated with self‐reported tanning behaviour. The Skin Tone Rating Scale was also moderately related to appearance reasons for tanning and internalisation of a tanned ideal, demonstrating concurrent validity. Socio‐cultural influences (from peers and media) were positively correlated with skin tone dissatisfaction, and this relationship was partially mediated by internalisation of a tanned ideal. Although more research is needed to establish causation, this study provides an important addition to sun tanning literature; it provides a new measure to predict self‐reported tanning behaviour, the Skin Tone Rating Scale, which highlights the importance of appearance concerns in relation to tanning and sun exposure.     

关于上下视野不对称性的研究

该研究就国内外对上下视野不对称性的研究成果做了详细的阐述,主要包括上下视野的定义、上下视野不对称性的行为和神经机制方面的研究成果及当前所面临的问题,并在文章的最后提出自己的观点。     

Intentional switching of auditory attention between long and short sequential tone patterns

The current study focuses on auditory task switching, more precisely on switching attention between different temporal patterns of the same auditory stimulus. Tone sequences consisting of nine different pitch tones were presented aurally. Three repetitive short 3-tone patterns (local focus) were combined to a long pattern (global focus), and each could be either rising or falling, resulting in congruent or incongruent combinations. Participants were informed by a cue if they had to attend to the short or to the long pattern, and they indicated if the target pattern was rising or falling by pressing one of two keys. In two experiments, we investigated cued switches between the two attentional foci. Switch costs in reaction times and errors were observed when switching from the long to the short pattern but not when switching from the short to the long pattern. These asymmetric switch costs were reduced when participants had more time to prepare for the switch in a condition with a prolonged cue-stimulus interval. In addition, participants made more errors when global and local patterns did not correspond to each other (i.e., in incongruent trials) when attending to either of the patterns, but this congruency effect was not modulated by preparation time. The data suggest that the mechanisms of task goal prioritizing, as indicated by the asymmetric attention switch costs, are dissociable from those underlying stimulus selection, as indicated by the congruency effects.