Tempo discrimination in infants

An habituation/dishabituation paradigm demonstrates that 2- and 4-month-old infants are able to discriminate auditory sequences that vary slightly in tempo. Discriminations were only observed for intermediate tempi (600 ms but not 100, 300, 1500 ms IOI), suggesting that infants have the same optimal tempo range as adults.     

Discrimination of pitch contours by neonates

With the high-amplitude sucking procedure, newborns were presented with two lists of phonetically varied Japanese words differing in pitch contour. Discrimination of the lists was found, thus indicating that newborns are able to extract pitch contour information at the word level.     

A Domain-General Theory of the Development of Perceptual Discrimination

ABSTRACT— In this article, we posit a domain-general principle that may account for the improvement that is observed in several aspects of perceptual development over the first years of life. Development during this time frame is characterized by a process of perceptual narrowing, whereby the discrimination of perceptual information is broadly tuned at first and then declines to more selective levels with experience. This process appears to cut across both the visual and auditory modalities and may reflect the development of a common neural architecture.     

知觉适应对种族融合面孔的种族分类和知觉辨别的影响

面孔加工的种族效应(the other-race effects)指人们对面孔做个体辨别任务时辨别本族面孔的绩效优于辨别他族面孔的绩效, 而做种族分类任务时分类他族面孔的绩效优于分类本族面孔的绩效。本研究通过知觉适应操纵被试对种族两歧(高加索和亚洲)融合面孔的种族知觉, 进而比较被试在两种条件下对同一张融合面孔进行种族分类和知觉辨别的绩效的差异。结果发现, 知觉适应能使被试产生将两歧融合面孔知觉为与原始面孔所属种族相反种族的知觉偏向, 并且, 伴随着这种知觉偏向, 两歧融合面孔的加工出现了他族分类优势和本族辨别优势, 提示社会认知因素对面孔加工的种族效应有重要作用。     

Racial Differences in Perceptions of Starting Salaries: How Failing to Discriminate Can Perpetuate Discrimination

Despite recent findings suggesting the presence of racial differences in the perception of starting salaries, researchers have yet to empirically investigate this possibility. Consequently, this study examined the interactive effects of race, ethnic identity, and starting salaries on the salary perceptions of 342 undergraduates. Hispanic, Asian American, and White participants exhibited positive effects of salary whereas Black respondents failed to discriminate between the different salaries. However, a three-way interaction involving ethnic identity, race, and salary revealed a more complex pattern of responses for Black participants: Higher ethnic identifiers responded similarly to Hispanic, White, and Asian Americans. The implications of these results regarding the perpetuation of racial wage inequity are discussed.     

Discrimination and differentiation of response number in stimulus directed pecking of pigeons.

In Experiment 1, autoshaping trials terminated with food only if pigeons emitted more than a target number of responses during a trial in one condition and fewer than a target number in another. The median number of responses per trial shifted in accordance wtih the requirements. The responding of yoked-control birds that received response-independent reinforcers did not vary with the response requirements. In Experiment 2, the number of responses in autoshaping trial became the discriminative stimulus for reinforcement in the second component of a chained schedule. In one condition, responding was reinforced only if the number of responses in the first component was above a target value; in the other condition, responding was reinforced only if the number was below the target value. The distribution of the first-component response numbers did not shift systematically between discrimination conditions, but response rates in the second component indicated that the number of responses in the autoshaping trial was a discriminable property behavior.     

Discrimination of faces by young infants

An experiment was conducted to obtain normative data concerning discrimination between human faces by infants under 6 months of age and to determine the information base required for this performance. Infants were habituated to a specific face and recovery of attention was monitored to a novel face, where one or more features was common to both faces. Results suggested that discrimination between photographs of adult, female faces is possible from 5 weeks of age, with critical information probably lying in the hair-face outline while internal features were relatively unimportant until the 19th week.     

Developmental Improvements in Perceptual Restoration: Can Young Children Reconstruct Missing Sounds in Noisy Environments?

Young children are frequently exposed to sounds such as speech and music in noisy listening conditions, which have the potential to disrupt their learning. Missing input that is masked by louder sounds can, under the right conditions, be ‘filled in’ by the perceptual system using a process known as perceptual restoration. This experiment compared the ability of 4‐ to 6‐year‐old children, 9‐ to 11‐year‐old children and adults to complete a melody identification task using perceptual restoration. Melodies were presented either intact (complete input), with noise‐filled gaps (partial input; perceptual restoration can occur) or with silence‐filled gaps (partial input; perceptual restoration cannot occur). All age groups could use perceptual restoration to help them interpret partial input, yet perception was the most detrimentally affected by the presentation of partial input for the youngest children. This implies that they might have more difficulty perceiving sounds in noisy environments than older children or adults. Young children had particular difficulty using partial input for identification under conditions where perceptual restoration could not occur. These findings suggest that perceptual restoration is a crucial mechanism in young children, where processes that fill in missing sensory input represent an important part of the way meaning is extracted from a complex sensory world. Copyright © 2011 John Wiley & Sons, Ltd.     

反疾病歧视立法的相关问题探讨

许多国家已对遭遇疾病歧视的患者给予法律上的保护,而我国现有的法律不足以保护受歧视者权益。通过权衡疾病患者在工作生活中所受歧视的利弊,并从多角度分析,提出我国应进行相关立法,保护受歧视者的合法权益。     

The use of prosodic cues in language discrimination tasks by rats

Recent research with cotton-top tamarin monkeys has revealed language discrimination abilities similar to those found in human infants, demonstrating that these perceptual abilities are not unique to humans but are also present in non-human primates. Specifically, tamarins could discriminate forward but not backward sentences of Dutch from Japanese, using both natural and synthesized utterances. The present study was designed as a conceptual replication of the work on tamarins. Results show that rats trained in a discrimination learning task readily discriminate forward, but not backward sentences of Dutch from Japanese; the results are particularly robust for synthetic utterances, a pattern that shows greater parallels with newborns than with tamarins. Our results extend the claims made in the research with tamarins that the capacity to discriminate languages from different rhythmic classes depends on general perceptual abilities that evolved at least as far back as the rodents. Electronic Publication     

Discrimination of intentional and random motion paths by pigeons

Twelve pigeons (Columba livia) were trained on a go/no-go schedule to discriminate between two kinds of movement patterns of dots, which to human observers appear to be "intentional" and "non-intentional" movements. In experiment 1, the intentional motion stimulus contained one dot (a "wolf") that moved systematically towards another dot as though stalking it, and three distractors ("sheep"). The non-intentional motion stimulus consisted of four distractors but no stalker. Birds showed some improvement of discrimination as the sessions progressed, but high levels of discrimination were not reached. In experiment 2, the same birds were tested with different stimuli. The same parameters were used but the number of intentionally moving dots in the intentional motion stimulus was altered, so that three wolves stalked one sheep. Despite the enhanced difference of movement patterns, the birds did not show any further improvement in discrimination. However, birds for which the non-intentional stimulus was associated with reward showed a decline in discrimination. These results indicated that pigeons can discriminate between stimuli that do and do not contain an element that human observer see as moving intentionally. However, as no feature-positive effect was found in experiment 1, it is assumed that pigeons did not perceive or discriminate these stimuli on the basis that the intentional stimuli contained a feature that the non-intentional stimuli lacked, though the convergence seen in experiment 2 may have been an effective feature for the pigeons. Pigeons seem to be able to recognise some form of multiple simultaneously goal-directed motions, compared to random motions, as a distinctive feature, but do not seem to use simple "intentional" motion paths of two geometrical figures, embedded in random motions, as a feature whose presence or absence differentiates motion displays. Electronic Publication     

Discrimination by young infants of stimuli presented discontinuously

Four experiments are reported showing that young infants can pick up visual information from very brief displays. Pattern, edge orientation, and form can be discriminated when stimuli are presented for repeated exposures of only 300 ms.     

Shrinkage in the perceived duration of speech and tone by acoustic replacement1

Abstract: To investigate mechanisms for perceiving the duration of an auditory event, an effect of perceptual grouping upon perceived duration was studied psychophysically. In the first experiment, the perceived duration of a spoken word was measured under three conditions of acoustic continuity (i.e., (a) intact, (b) noise‐replaced, and (c) gap‐replaced) as a function of the duration of the target stimulus. Under the noise‐replaced condition, a portion of the target stimulus was physically replaced with a noise burst. Under the gap‐replaced condition, the replacement was made with a gap. The gap‐replacement resulted in a prominent shrinkage of the perceived duration. In the case of noise‐replacement, the amount of shrinkage was moderate but highly significant, although the word employed was perceived to be phonetically intact. Independent of this effect of replacement, the amount of shrinkage was also affected by the physical duration of the target stimulus. The second experiment tested an effect of noise replacement on the perceived duration of a tone burst. In this case, the noise replacement also shrunk the perceived duration of the non‐speech stimulus. This noise‐induced shrinkage could be regarded as being general for the auditory duration. The phenomenon is discussed in relation to a revised model for perceived duration.     

Discrimination of polysyllabic sequences by one- to four-month-old infants

The goal of this research was to ascertain the effects of suprasegmental parameters (fundamental frequency, amplitude, and duration) on discrimination of polysyllabic sequences by 1- to 4-month-old infants. A high-amplitude sucking procedure, with synthesized female speech, was used. Results indicate that young infants can discriminate the three-syllable sequences [marana] versus [malana] when suprasegmental characteristics typical of infant-directed speech emphasize the middle syllable. However, infants failed to demonstrate discrimination when adult-directed suprasegmentals were used and in several other experimental conditions in which prosodic parameters were manipulated. The pattern of results obtained in the six experiments suggests that the exaggerated suprasegmentals of infant-directed speech may function as a perceptual catalyst, facilitating discrimination by focusing the infant's attention on a distinctive syllable within polysyllabic sequences.     

陈霖的拓扑性质知觉理论

2005年第四期“Visual Cognition”期刊专题讨论了拓扑知觉理沧,包括陈霖的主题文章、对这篇文章的评论以及陈霖对这些评论的答复。本文从三个方面介绍了陈霖的拓扑性质知觉理沦：拓扑性质的早期知觉、知觉物体的定义以及拓扑性质知觉理论的意义。