Perception of time-compressed consonant-nucleus-consonant monosyllables by non-native speaker/listeners of English

Recent investigations of time-altered speech have dealt with the effect of time compression and sensation level on intelligibility scores of native speaker/listeners of English. In the present investigation, the intelligibility of time-compressed consonant-nucleus-consonant monosyllables was studied using English speaker/listeners whose native languages are Spanish or Indo-Dravidian. Results supported earlier findings in that intelligibility decreased as a function of increasing percentage of time compression and decreasing sensation level. This effect was more prominent for the Indo-Dravidian than for Spanish speaker/listeners. The Spanish group of subjects showed generally lower difference scores than did the Indo-Dravidian group when compared to native English speaker/listeners.     

Perception of /r/ and /l/ in a stop cluster: Evidence of cross-modal context effects.

Experiments were conducted investigating unimodal and cross-modal phonetic context effects on /r/ and /l/ identifications to test a hypothesis that context effects arise in early auditory speech processing. Experiment 1 demonstrated an influence of a preceding bilabial stop consonant on the acoustic realization of /r/ and /l/ produced within the stop clusters /ibri/ and /ibli/. In Experiment 2, members of an acoustic /iri/ to /ili/ continuum were paired with an acoustic /ibi/. These dichotic tokens were associated with an increase in "l" identification relative to the /iri/ to /ili/ continuum. In Experiment 3, the /iri/ to /ili/ tokens were dubbed onto a video of a talker saying /ibi/. This condition was associated with a reliable perceptual shift relative to an auditory-only condition in which the /iri/ to /ili/ tokens were presented by themselves, ruling out an account of these context effects as arising during early auditory processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Time and context effects on performance in a Pavlovian discrimination reversal.

Five conditioned suppression experiments with rats explored retention interval and context effects in discrimination reversal learning. In the discrimination phase, a tone (T) was paired with shock, and a houselight-off stimulus (L) was presented alone; in the reversal phase, T was extinguished and L was paired with shock. Discrimination training made L a latent inhibitor but not a conditioned inhibitor. A 28-day delay after the reversal caused spontaneous recovery to T but had no effect on L. A context switch before the reversal caused more rapid conditioning to L but did not affect extinction to T. A return to the original context after the reversal had occurred in a different context renewed suppression to T and latent inhibition to L; contextual control was strong 21 days later. Tests in a neutral context indicated that each training context controlled performance to T and L. A memory retrieval framework may begin to integrate the effects of context and time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of talker familiarity on spoken word identification in younger and older listeners.

The present study was designed to examine age differences in the ability to use voice information acquired intentionally (Experiment 1) or incidentally (Experiment 2) as an aid to spoken word identification. Following both implicit and explicit voice learning, participants were asked to identify novel words spoken either by familiar talkers (ones they had been exposed to in the training phase) or by 4 unfamiliar voices. In both experiments, explicit memory for talkers' voices was significantly lower in older than in young listeners. Despite this age-related decline in voice recognition, however, older adults exhibited equivalent, and in some cases greater, benefit than young listeners from having words spoken by familiar talkers. Implications of the findings for age-related changes in explicit versus implicit memory systems are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differential effects of visual context on pattern discrimination by pigeons (Columba livia) and humans (Homo sapiens).

Three experiments examined the role of contextual information during line orientation and line position discriminations by pigeons (Columba livia) and humans (Homo sapiens). Experiment 1 tested pigeons' performance with these stimuli in a target localization task using texture displays. Experiments 2 and 3 tested pigeons and humans, respectively, with small and large variations of these stimuli in a same-different task. Humans showed a configural superiority effect when tested with displays constructed from large elements but not when tested with the smaller, more densely packed texture displays. The pigeons, in contrast, exhibited a configural inferiority effect when required to discriminate line orientation, regardless of stimulus size. These contrasting results suggest a species difference in the perception and use of features and contextual information in the discrimination of line information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Communication in context: Effects of speaker status on the comprehension of indirect requests.

Four experiments, using 296 university students, were conducted to examine how a speaker's status can affect the comprehension of conventional and nonconventional indirect requests. The processing of conventional forms was not affected by the speaker's relative status, and consistent with past research (R. W. Gibbs; see record 1984-05770-001), these forms were recognized quickly and without the hearer recognizing and then rejecting the literal meaning of the remark. In contrast, processing of nonconventional forms was affected by speaker status. When the interactants were equal in status, the comprehension of nonconventional forms was time-consuming and involved activation of the remark's literal meaning. This did not occur when the speaker was higher in status than the hearer. Results illustrate the role played by the interpersonal context in the comprehension of certain indirect requests. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perservative errors in object discrimination learning by aged Japanese monkeys (Macaca fuscata).

To examine the nature of age-dependent cognitive decline, performance in terms of concurrent object discriminations was assessed in aged and nonaged Japanese monkeys (Macaca fuscata). Aged monkeys required more sessions and committed more errors than nonaged ones in the discriminations, even in simple object discriminations. Analyses of errors suggest that aged monkeys repeated the same errors and committed more errors when they chose a negative object at the 1st trial. A hypothesis analysis of behavior suggests that their incorrect choices were mainly due to object preference. Therefore, the impairment was probably caused by a failure to inhibit inappropriate responses. Together with previous neuropsychological findings, deficits of aged monkeys in the performance of object discriminations can be explained by dysfunction of the frontal cortex. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of motivational context on conspecific song discrimination by brown-headed cowbirds (Molothrus ater).

Two experiments to examine the effects of motivational context on the perception of conspecific song by cowbirds were conducted. In the 1st experiment, sexual displays were elicited from females by playback of normal song and rearranged sequences of the component phrases. In a 2nd experiment, male and female cowbirds discriminated among the same songs in a food-rewarded operant procedure. In a sexual context, the birds were sensitive to both the beginning and end phrases of normal song, whereas in a food context, the birds were more sensitive to the beginning of normal song. In both experiments, 1-phrase songs were better discriminated from normal song than 2-phrase songs, and there was no effect of phrase order on discrimination. Similarities and differences in the results of the 2 experiments suggest that some aspects of cowbird song perception remain constant across motivational contexts, whereas others are unique to particular motivational contexts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceived discrimination, sense of control, and depressive symptoms among Korean American older adults.

This study explored a potential pathway by which perceived discrimination may affect levels of depressive symptoms in a sample of 472 Korean American older adults (Mage = 69.9, SD = 7.04). Building upon previous studies demonstrating that perceived discrimination has negative impacts on mental health, we hypothesized that sense of control would mediate the associations between perceived discrimination and depressive symptoms. Our analyses showed that the effects of perceived discrimination on depressive symptoms were not only direct but also mediated through a lowered sense of control. Finding that sense of control serves as an intervening step between perceived discrimination and mental health may help explicate the psychological mechanisms involved in responses to discriminatory experience and has implications for intervention strategies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Functional anatomy of human odor sensation, discrimination, and identification in health and aging.

Aging of cerebral olfactory regions was studied in 5 younger and 6 older healthy adults, matched by odor discrimination and identification scores, with positron emission tomography during odor sensory stimulation, discrimination, and identification tasks. Sensory stimulation engaged bilateral piriform and orbitofrontal regions, but neither discrimination nor identification evoked added temporal or orbital activity. Discrimination involved the hippocampus, implicating its role in serial odor comparisons (olfactory working memory). Left inferior frontal activity during identification may reflect semantic associations. Older participants deactivated the left gyrus rectus/medial orbital gyrus (GR/MOG) during sensory stimulation but activated GR/MOG during discrimination and identification. Adjusting for detection threshold eliminated GR/MOG group differences during sensory stimulation. Diminished threshold may lead to reduced engagement of olfactory association areas. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Language discrimination by newborns: Toward an understanding of the role of rhythm.

Three experiments investigated the ability of French newborns to discriminate between sets of sentences in different foreign languages. The sentences were low-pass filtered to reduce segmental information while sparing prosodic information. Infants discriminated between stress-timed English and mora-timed Japanese (Experiment 1) but failed to discriminate between stress-timed English and stress-timed Dutch (Experiment 2). In Experiment 3, infants heard different combinations of sentences from English, Dutch, Spanish, and Italian. Discrimination was observed only when English and Dutch sentences were contrasted with Spanish and Italian sentences. These results suggest that newborns use prosodic and, more specifically, rhythmic information to classify utterances into broad language classes defined according to global rhythmic properties. Implications of this for the acquisition of the rhythmic properties of the native language are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Distance and magnitude effects in sequential number discrimination by pigeons.

Number discrimination experiments with humans and monkeys have revealed distance and magnitude effects. When required to choose the more frequently occurring stimulus between two stimuli presented repeatedly in sequence, accuracy improves as the distance between number increases (distance effect) and decreases as distance is held constant and the size of the numbers increases (magnitude effect). These effects were shown in three experiments reported with pigeons as subjects. It was shown that a single model based on discrimination between noisy numerical representations could account for both the primate and bird findings. To model the pigeon data, an additional decay parameter was necessary to account for strong recency effects found for the influence on choice of terminal stimuli presented in a sequence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sexual dimorphism in facial shapes and their discrimination in Japanese monkeys (Macaca fuscata).

The authors examined the ability of Japanese monkeys (Macaca fuscata) to discriminate between sexes based on facial features. The shape and position of facial features (facial morphology) were measured to quantify the differences between sexes. The distance between the chin and nose was longer in males than females, and the outline of the face around the upper jaw and upper face differed between sexes. Using operant conditioning, 2 monkeys succeeded in discriminating sex based on facial pictures. Furthermore, they successfully generalized the discrimination to novel pictures of faces. Tests with morphed pictures of faces revealed that the monkeys used facial morphology to discriminate between males and females. Our results suggest that Japanese monkeys have sexual dimorphism in facial shape and they can use the morphological differences to discriminate conspecific sex. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spectral envelope and context effects in the tritone paradox

In previous studies of the 'tritone paradox' Deutsch has suggested that, when listeners are presented with pairs of octave-complex tones that are equal in average log frequency but differ in chroma by 6 semitones (a tritone), they perceive the direction of the chroma difference according to an individual pitch-class template. However, it has also been found that the perceived direction changes for many listeners when the spectral envelope of the tones is shifted along the frequency axis. Reanalysis of these data indicates a strong tendency to perceive the pitch class corresponding to the frequency on which the spectral envelope is centered as subjectively lowest. In experiment 1 this spectral-envelope effect was replicated with tone pairs presented in isolation, at the rate of one a day, which rules out artifacts of test format. In experiment 2, involving another context-free format, envelope center frequency was varied over a wide range and it was shown that some individuals are totally envelope dependent, whereas others rely more on pitch class, and yet others show mixed patterns. Experiment 3 demonstrated that listeners' judgments of tritone pairs can be swayed easily by preceding context. Finally, experiment 4 showed that strong envelope effects are also obtained with Deutsch's own tritone test (issued on CD). The subjective relative pitch height of octave-complex tones thus depends on several competing factors, only one of which is pitch class.     

Serial position effects in the identification of letters, digits, and symbols.

In 6 experiments, the authors investigated the form of serial position functions for identification of letters, digits, and symbols presented in strings. The results replicated findings obtained with the target search paradigm, showing an interaction between the effects of serial position and type of stimulus, with symbols generating a distinct serial position function compared with letters and digits. When the task was 2-alternative forced choice, this interaction was driven almost exclusively by performance at the first position in the string, with letters and digits showing much higher levels of accuracy than symbols at this position. A final-position advantage was reinstated in Experiment 6 by placing the two alternative responses below the target string. The end-position (first and last positions) advantage for letters and digits compared with symbol stimuli was further confirmed with the bar-probe technique (postcued partial report) in Experiments 5 and 6. Overall, the results further support the existence of a specialized mechanism designed to optimize processing of strings of letters and digits by modifying the size and shape of retinotopic character detectors' receptive fields. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Guessing strategies, aging, and bias effects in perceptual identification

In the typical single-stimulus perceptual identification task, accuracy is improved by prior study of test words, a repetition priming benefit. There is also a cost, inasmuch as previously studied words are likely to be produced (incorrectly) as responses if the test word is orthographically similar but not identical to a studied word. In two-alternative forced-choice perceptual identification, a test word is flashed and followed by two alternatives, one of which is the correct response. When the two alternatives are orthographically similar, test words identical to previously studied items are identified more accurately than new words (a benefit) but tests words orthographically similar to studied words are identified less accurately than new words (a cost). Ratcliff and McKoon (in press) argue that these are bias effects that arise in the decision stage of word identification. We report five experiments that examined the alternative hypothesis that these bias effects arise from postperceptual guessing strategies. In single-stimulus perceptual identification, repetition priming benefits were equally great for young and older adults who claimed to use deliberate guessing strategies and those who did not (Experiment 1). In contrast, only groups of young and older people who claimed to deliberately guess studied words in a two-alternative forced-choice task (Experiments 2 and 5) showed reliable benefits and costs. Costs and benefits were abolished in the two-alternative forced-choice task when a very long study list was used, presumably because the increased retrieval burden made the use of deliberate guessing strategies less attractive (Experiment 3). Under conditions similar to those of Experiment 3, repetition priming was observed in single-stimulus perceptual identification (Experiment 4). These results are consistent with the view that costs and benefits in the forced-choice perceptual identification task arise from deliberate guessing strategies but that those in the single-stimulus task do not. The possibility that the observed relationship between strategy reports and priming effects reflects erroneous postexperimental assessments of strategies by participants is also considered.     

Consistency, frequency, and lexicality effects in naming Japanese Kanji.

Japanese Kanji characters have various degrees of consistency of character-sound correspondences in multicharacter words. A word was classified as consistent, inconsistent typical, or inconsistent atypical with reference to the most typical pronunciations for constituent characters among words sharing the same characters. A nonword was classified as consistent, inconsistent biased, or inconsistent ambiguous according to the degree of pronunciation typicality of its constituent characters in real words. A word-naming experiment yielded a significant Frequency?×?Consistency interaction, and a nonword-naming experiment yielded significant consistency effects. In addition, both word frequency and lexicality exerted strong effects on efficiency of naming Kanji character strings. These results demonstrate the influence of Kanji print-sound correspondences both at subword and whole-word levels. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Status, age, and sex effects on performance of discrimination tasks in group-tested rhesus monkeys (Macaca mulatta).

To assess the relation between performance and social or demographic variables, this study group tested a captive monkey colony on visual and manual discrimination problems. Animals could choose between differently colored, sand-filled boxes, where hue signaled the initial probability of finding buried food items. Dominant animals and subadults were most successful in locating and retrieving incentives, but sex did not affect performance. Rank effects occurred without overt aggression, suggesting deference by subordinates as a mediating mechanism. Age effects may reflect changing attention patterns only evident in complex arenas where cue salience becomes diluted. Because these findings differ from studies of singly tested animals, they show that, in a social context, an individual's rank and age may define opportunities to gain or efficiently use information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)