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.     

On sense and senses: Intelligence and auditory information processing

Brighter people process information faster than the less bright on a variety of cognitive tasks, but interpretation of this observation is ambiguous. The first two experiments here emphasize discrimination ability while downplaying speed-of-processing, yet indicate significant aptitude-related differences. Both experiments involve frequency discrimination of two 20-msec tones in the absence of any masking using a two-interval forced choice procedure. Correlations of frequency discrimination thresholds with Cattell's Culture Fair Intelligence Test IQ in college students range between -0.42 and -0.54. Placing more emphasis on resolution than speed, the results suggest that higher intelligence may be associated with greater resolution capacity, which in turn may increase speed of performance. The third experiment tested the hypothesis that brighter people perform better on any novel ‘nonentrenched’ task. Brief tone bursts were embedded in broadband noise, in notched noise (distracting, but containing no frequencies near the fundamental of the target tone), or in quiet. No aptitude-related differences in signal detection thresholds were observed, suggesting that aptitude-related effects of novelty per se are an unlikely explanation for the superior frequency discrimination performance of brighter college students. Detection tasks, in contrast to recognition tasks, do not tap the ‘higher’ cognitive functions associated with psychometric intelligence.     

Noise and the "rehearsal-masking hypothesis"

This study examines the proposal that continuous loud noise impairs short-term recall by masking the inner speech necessary to rehearse material in memory (Poulton, 1976 a, 1977 b). The "masking hypothesis" contrasts with previous theories which relate recall impairment in noise to the latter's action in over-arousing the individual or inducing changes in attentional deployment. Separate groups performed a visual, serial eight-consonant recall task in either 92 dBA "noise" or 75 dBA "quiet" and in "normal" or "suppressed" rehearsal conditions. The masking hypothesis predicted that noise would impair recall relative to quiet in normal rehearsal conditions. But where the rehearsal of both groups was already suppressed by a concurrent articulatory task, recall would not differ between the groups through noise-masking then being irrelevant. Total correct recall scores appeared to confirm the masking hypothesis but the pattern of serial order recall showed differences between noise and quiet in suppressed rehearsal conditions which seemed better explained by an attentional influence of noise. Further, reduced commission and acoustic confusion errors in noise were not consistent with the predictions of the masking hypothesis. It was concluded that noise-masking could not be refuted but that attentional changes due to the arousing action of noise might also be active determinants of recall.     

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.     

Working memory affects older adults’ use of context in spoken-word recognition

Many older listeners report difficulties in understanding speech in noisy situations. Working memory and other cognitive skills may modulate older listeners’ ability to use context information to alleviate the effects of noise on spoken-word recognition. In the present study, we investigated whether verbal working memory predicts older adults’ ability to immediately use context information in the recognition of words embedded in sentences, presented in different listening conditions. In a phoneme-monitoring task, older adults were asked to detect as fast and as accurately as possible target phonemes in sentences spoken by a target speaker. Target speech was presented without noise, with fluctuating speech-shaped noise, or with competing speech from a single distractor speaker. The gradient measure of contextual probability (derived from a separate offline rating study) affected the speed of recognition. Contextual facilitation was modulated by older listeners’ verbal working memory (measured with a backward digit span task) and age across listening conditions. Working memory and age, as well as hearing loss, were also the most consistent predictors of overall listening performance. Older listeners’ immediate benefit from context in spoken-word recognition thus relates to their ability to keep and update a semantic representation of the sentence content in working memory.     

Frequency discrimination near masked threshold

Frequency DLs (Δf) at 1000 Hz were obtained in quiet and under masking conditions similar to those used in pitch-shift experiments, narrow-band noise at levels of 60, 80, and 100 dB SPL and tones at 15 dB SL or less. The Δfs were obtained by means of a tracking task in which the S controlled the input voltage to a frequency modulator. Characteristic improvement was seen when Δf was plotted as a function of sensation level. However, noise level itself was a significant factor, with more intense noise resulting in larger Δfs for tones of equal sensation level re masked threshold. This departure from previous findings is attributed to the signal and noise levels used, although the possibility exists that it is due to the use of modulated tones.     

Stimulus intensity, attentional instructions, and the ear advantage during dichotic listening

The present experiment was designed to investigate the effects of the following two variables on the identification of dichotically presented CV syllables: (1) the relative difference in intensity levels of the stimuli presented to the two ears and (2) the instructions to attend to both ears or to focus attention on one ear. As expected for a verbal task, more CV's were identified from the right ear than from the left ear. Furthermore, identification of stimuli presented to one ear improved when (1) those stimuli were relatively higher in volume than the stimuli presented to the other ear and (2) when subjects were instructed to focus attention on only that ear rather than distribute attention across both ears. Of particular importance is the finding that the effects of relative stimulus intensity are the same under conditions of focused attention as under conditions of divided attention. This finding is inconsistent with an attention explantation of the relative intensity effects. Instead, the results are consistent with a model of dichotic listening in which ear of stimulus presentation and relative stimulus intensity influence a perceptual stage of information processing and attentional instructions influence a subsequent response selection stage.     

When the voluntary mind meets the irresistible event: Stimulus–response correspondence effects on task selection during voluntary task switching

In the present study, we investigated how task selection is biased by inherent stimulus characteristics in the voluntary task-switching paradigm. We used digits as the task stimuli, since they may automatically induce spatially horizontal representations of numbers. Specifically, we examined whether an irrelevant spatial representation of a number coincides with its associated response codes and whether such a stimulus–response (S–R) correspondence effect biases task selection for a digit. Participants were randomly assigned to one of two different action code layout conditions: Two numerical tasks were arranged as inner/outer in the horizontal layout condition or as upper/down in the vertical layout condition. Participants in the horizontal layout condition were more likely to choose a task when the task’s action code and the digit’s spatial representation corresponded, as compared with when they did not. On the other hand, no selection bias was observed in the vertical layout condition, since there was no overlapping spatial representation between the stimulus and response. The present study extends previous findings by considering the influence of the stimulus-driven effect on task selection with regard to the S–R correspondence effect.     

Do realistic reverberation levels reduce auditory distraction?

Acoustically treated ceilings and wall panels can be used as part of a strategy to reduce the impact of background sound on the health and performance of employees by decreasing the reverberation times of the office noise. In this article we examine the impact of two reverberation times upon task performance. A cognitive task known to be a sensitive index of auditory distraction (serial recall) was used to assess the degree of distraction associated with two types of ceiling: a hard ceiling, such as plasterboard, and a soft ceiling, such as an acoustically treated ceiling. Office noise (in the range 65–75 dB (A)) was found generally to be disruptive relative to a quiet control condition but there was no difference in performance with regard to the ceiling types. Copyright © 2006 John Wiley & Sons, Ltd.     

Psychophysical investigation of vigilance decrement in jumping spiders: overstimulation or understimulation?

The inability to maintain signal detection performance with time on task, or vigilance decrement, is widely studied in people because of its profound implications on attention-demanding tasks over sustained periods of time (e.g., air-traffic control). According to the resource depletion (overload) theory, a faster decrement is expected in tasks that are cognitively demanding or overstimulating, while the underload theory predicts steeper decrements in tasks that provide too little cognitive load, or understimulation. Using Trite planiceps, a jumping spider which is an active visual hunter, we investigated vigilance decrement to repetitive visual stimuli. Spiders were tethered in front of two stimulus presentation monitors and were given a polystyrene ball to hold. Movement of this ball indicates an attempt to turn towards a visual stimulus presented to a pair of laterally facing (anterior lateral) eyes for closer investigation with high acuity forward-facing (anterior median) eyes. Vigilance decrement is easily measured, as moving visual stimuli trigger clear optokinetic responses. We manipulated task difficulty by varying the contrast of the stimulus and the degree of ‘noise’ displayed on the screen over which the stimulus moved, thus affecting the signal:noise ratio. Additionally, we manipulated motivation by paired testing of hungry and sated spiders. All factors affected the vigilance decrement, but the key variable affecting decrement was stimulus contrast. Spiders exhibited a steeper decrement in the harder tasks, aligning with the resource depletion theory.     

How the mind shapes action: Offline contexts modulate involuntary episodic retrieval

Involuntary retrieval of previous stimulus–response episodes is a centerpiece of many theories of priming, episodic binding, and action control. Typically it is assumed that by repeating a stimulus from trial n–1 to trial n, involuntary retrieval is triggered in a nearly automatic fashion, facilitating (or interfering with) the to-be-executed action. Here we argue that changes in the offline context weaken the involuntary retrieval of previous episodes (the offline context is defined to be the information presented before or after the focal stimulus). In four conditions differing in cue modality and target modality, retrieval was diminished if participants changed the target selection criterion (as indicated by a cue presented before the selection took place) while they still performed the same task. Thus, solely through changes in the offline context (cue or selection criterion), involuntary retrieval can be weakened in an effective way.     

Effects of glide slope,noise intensity,and noise duration on the extrapolation of FM glides through noise

Listeners are quite adept at maintaining integrated perceptual events in environments that are frequently noisy. Three experiments were conducted to assess the mechanisms by which listeners maintain continuity for upward sinusoidal glides that are interrupted by a period of broadband noise. The first two experiments used stimulus complexes consisting of three parts: prenoise glide, broadband noise interval, and postnoise glide. For a given prenoise glide and noise interval, the subject’s task was to adjust the onset frequency of a same-slope postnoise glide so that, together with the prenoise glide and noise, the complex sounded as “smooth and continuous as possible.” The slope of the glides (1.67, 3.33, 5, and 6.67 Bark/sec) as well as the duration (50, 200, and 350 msec) and relative level of the interrupting noise (0, ?6, and ?12 dB S/N) were varied. For all but the shallowest glides, subjects consistently adjusted the offset portion of the glide to frequencies lower than predicted by accurate interpolation of the prenoise portion. Curiously, for the shallowest glides, subjects consistently selected postnoise glide onset-frequency values higher than predicted by accurate extrapolation of the prenoise glide. There was no effect of noise level on subjects’ adjustments in the first two experiments. The third experiment used a signal detection task to measure the phenomenal experience of continuity through the noise. Frequency glides were either present or absent during the noise for stimuli like those used in the first two experiments as well as for stimuli that had no prenoise or postnoise glides. Subjects were more likely to report the presence of glides in the noise when none occurred (false positives) when noise was shorter or of greater relative level and when glides were present adjacent to the noise.     

Voluntary task switching under load: Contribution of top-down and bottom-up factors in goal-directed behavior

The present study investigated the relative contribution of bottom-up and top-down control to task selection in the voluntary task-switching (VTS) procedure. In order to manipulate the efficiency of top-down control, a concurrent working memory load was imposed during VTS. In three experiments, bottom-up factors, such as stimulus repetitions, repetition of irrelevant information, and stimulus-task associations, were introduced in order to investigate their influence on task selection. We observed that the tendency to repeat tasks was stronger under load, suggesting that top-down control counteracts the automatic tendency to repeat tasks. The results also indicated that task selection can be guided by several elements in the environment, but that only the influence of stimulus repetitions depends on the efficiency of top-down control. The theoretical implications of these findings are discussed within the interplay between top-down and bottom-up control that underlies the voluntary selection of tasks.     

Reference frames for orientation anisotropies in face recognition and biological-motion perception

Both face recognition and biological-motion perception are strongly orientation-dependent. Recognition performance decreases if the stimuli are rotated with respect to their normal upright orientation. Here, the question whether this effect operates in egocentric coordinates or in environmental coordinates is examined. In addition to the use of rotated stimuli the observers were also rotated and tested both with a same-different face-recognition task and with a biological-motion detection task. A strong orientation effect was found that depended only on the stimulus orientation relative to the observer. This result clearly indicates that orientation effects in both stimulus domains operate in an egocentric frame of reference. This finding is discussed in terms of the particular requirement of extracting sophisticated information for social recognition and communication from faces and biological motion.     

Effects of white noise and irrelevant information on speeded classification: A developmental study

The study examined how well subjects were able to ignore the presence of irrelevant stimulus information in noise and in silence, as a function of age. Children aged six and nine, and adults, performed speeded card-sorting tasks with one binary dimension relevant and zero or two dimensions irrelevant. The presence of irrelevant information interfered with performance, the magnitude of interference declining with age. The interfering effects of irrelevant information were greater when it was (relatively) more salient than when it was less salient, but there was no interaction between relative salience and the effects of noise. Noise (95 dB(A)) slowed down sorting performance of adult subjects in all conditions, it slightly improved the performance of nine-year-old children, and it improved the performance of six-year-old children significantly when irrelevant information was present. The effects of noise on attentional control are discussed, mainly with reference to inhibitory effects of noise on subvocal activity.     

Recall and Recognition Measures of Paired Associate Learning in Healthy Aging

ABSTRACT

Associate-recognition has received little attention as a potential clinical tool for detecting early Alzheimer's disease (AD). As an important preliminary stage to investigating the paradigm's diagnostic utility, we designed and administered a verbal associate-recognition task to healthy elderly participants (n?=?62) and compared their performance to that on traditional cued-recall PAL. In both test conditions, the stimulus list comprised of a mixture of highly imageable and less imageable word pairs. Overall, performance on the associate-recognition task was superior to that on the cued-recall analogue. This ‘recognition advantage’ was not attributable to the higher baseline or chance guessing rate in the associate-recognition condition, as the size of the recognition advantage varied across learning trials and stimulus imageability. In comparison to performance on the imageable stimuli, performance on the less imageable stimuli was poor in both associate-recognition and cued-recall conditions. Across the delay, performances were more likely to drop in the cued-recall condition than the associate-recognition condition. These results suggest that verbal associate-recognition may be clinically efficacious and better tolerated in elderly populations than traditional cued-recall paradigms. Although these results are encouraging, further research is required to examine the utility of associate-recognition in clinical populations, particularly early AD.     

Motion prediction and the velocity effect in children

In coincidence‐timing studies, children have been shown to respond too early to slower stimuli and too late to faster stimuli. To examine this velocity effect, children aged 6, 7.5, 9, 10.5, and adults were tested with two different velocities in a prediction‐motion task which consisted of judging, after the occlusion of the final part of its path, the moment of arrival of a moving stimulus towards a specified position. A similar velocity effect, resulting in later responses for the faster velocities than for the slower, was found primarily in the three younger groups of children (for the longer occlusion conditions: 600–1,320 milliseconds). However, this effect was not seen in all children in these groups. Individual analyses showed that this velocity effect, when present, is linked to the use of distance rather than time information, or to the confusion between these in extrapolating the occluded trajectories. The tendency to use one type of information or the other is a good predictor of accuracy and variability in this task and a good indicator of the development stage of the participants. Across development, children tend to initially use distance information with poor accuracy but relative consistency in responses. In a second stage, they use time and distance information alternatively across trials trying to find a better source of information with still poor accuracy and now great variability. In a final stage, they use time information to reach consistency and accuracy in their responses. This chronology follows the stages proposed by Savelesbergh and Van der Kamp (2000) explaining development with an initial stage of ‘freezing’ non‐optimal relationships between information and movement, then a ‘freeing’ stage during which new solutions are searched for, and finally an ‘exploiting’ stage with an optimal relationship between information and movement.     

Can preference for background music mediate the irrelevant sound effect?

Research suggests that listening to background music prior to task performance increases cognitive processes, such as attention and memory, through the mechanism of increasing arousal and positive mood. However, music preference has not been explored with regard to a more common and realistic scenario of concurrent music and cognition, namely the ‘irrelevant sound effect’ (ISE). To examine this, serial recall was tested under quiet, liked and disliked music sound conditions as well as steady‐state (repetition of ‘3’) and changing‐state speech (random digits 1–9). Results revealed performance to be poorer for both music conditions and the changing‐state speech compared to quiet and steady‐state speech conditions. The lack of difference between both music conditions suggests that preference does not affect serial recall performance. These findings are discussed within the music and cognition and auditory distraction literatures. Copyright © 2010 JohnWiley & Sons, Ltd.     

感觉记忆中含语义对象的视觉表征

感觉记忆能够以特征形式构建对视觉对象表面信息的表征, 然而对于具有重要意义的潜在抽象信息, 尚未有研究考察其是否影响感觉记忆的视觉表征。结合掩蔽技术与部分报告法范式考察了感觉记忆的视觉表征中是否包含语义信息。以阿拉伯数字作为目标, 实验1与实验2分别采用正立与倒置的汉字大写数字作为掩蔽刺激, 比较其与白噪音刺激的掩蔽效应。结果显示, 汉字大写数字的掩蔽效应均强于白噪音刺激, 且正立汉字大写数字的掩蔽效果较倒置汉字大写数字更强。实验3采用汉字大写数字与汉字常用字分别作为掩蔽刺激, 结果显示汉字大写数字的掩蔽效果强于汉字常用字。上述结果显示, 刺激间的语义相似性带来了视觉表征冲突, 表明感觉记忆的视觉表征中包含了刺激的语义信息。