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Hwei-bing Lin - One of the best experts on this subject based on the ideXlab platform.
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Effects of preceding context on the voice-onset-time Category Boundary
Journal of experimental psychology. Human perception and performance, 1991Co-Authors: Bruno H Repp, Hwei-bing LinAbstract:The Category Boundary on a voice-onset-time (VOT) continuum ranging from bin to pin shifts when the stimuli are preceded by different carrier phrases. By using a variety of precursor phrases, by varying the temporal interval between precursor and test word, and by selectively eliminating either voicing information or spectral structure from the precursors, the present experiments show that the context effect is caused by the presence or absence of voicing in the precursor's final segment. The effect decreases with temporal separation but persists over several seconds. In addition, the "baseline" VOT Boundary for isolated test words interspersed in a test sequence shifts depending on what precursor stimuli occur in the same sequence. The perception of VOT thus seems to be sensitive to both close and distant manifestations of laryngeal activity, always in an assimilative fashion, which suggests an integrative perceptual mechanism with a long time constant. Language: en
Joanne L Miller - One of the best experts on this subject based on the ideXlab platform.
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Contextual influences on the internal structure of phonetic categories: A distinction between lexical status and speaking rate
Perception & psychophysics, 2001Co-Authors: J. Sean Allen, Joanne L MillerAbstract:Previous research has shown that phonetic categories have a graded internal structure that is highly dependent on acoustic-phonetic contextual factors, such as speaking rate; these factors alter not only the location of phonetic Category boundaries, but also the location of a Category’s best exemplars. The purpose of the present investigation, which focused on the voiceless Category as specified by voice onset time (VOT), was to determine whether a higher order linguistic contextual factor, lexical status, which is known to alter the location of the voiced—voiceless phonetic Category Boundary, also alters the location of the best exemplars of the voiceless Category. The results indicated that lexical status has a more limited and qualitatively different effect on the Category’s best exemplars than does the acousticphonetic factor of speaking rate. This dissociation is discussed in terms of a production-based account in which perceived best exemplars of a Category track contextual variation in speech production.
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Contextual influences on the internal structure of phonetic categories: A distinction between lexical status and speaking rate
The Journal of the Acoustical Society of America, 1999Co-Authors: J. Sean Allen, Joanne L MillerAbstract:A series of experiments examined the effects of an acoustic‐phonetic contextual factor, speaking rate, and a higher‐order linguistic contextual factor, lexical status, on the internal structure of a voicing Category, specified by voice‐onset‐time (VOT). In keeping with previous results, speaking rate fundamentally altered the structure of the voiceless Category, not only affecting the perception of stimuli in the voiced–voiceless Category Boundary region but also altering which tokens were rated as the best exemplars of the voiceless Category. In contrast, the effect of lexical status was more limited. Although (as expected) lexical status also affected the perception of stimuli in the Category Boundary region, this effect disappeared in the region of the best‐rated exemplars. This distinction between the effects of speaking rate and lexical status on the internal structure of the voiceless Category mirrors the effects of these factors in speech production: It is well known that speaking rate alters the V...
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Internal structure of phonetic categories: effects of speaking rate.
Phonetica, 1997Co-Authors: Joanne L Miller, Timothy B. O’rourke, Lydia E VolaitisAbstract:Many studies have shown that listeners process speech in a rate-dependent manner, altering the location of phonetic Category boundaries in accord with the acoustic consequences of a change in rate during speech production. In a recent series of papers that focused on a voicing contrast, we reported that the perceptual adjustment for rate is not limited to the region of the Category Boundary, but extends to well within the Category, producing a change in which stimuli are perceived to be the best Category exemplars. In the current paper, we provide evidence for the generality of this effect by showing analogous results for a /b/-/w/ contrast, specified by transition duration. The implications of these findings for models of rate-dependent processing are discussed.
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phonetic prototypes influence of place of articulation and speaking rate on the internal structure of voicing categories
Journal of the Acoustical Society of America, 1992Co-Authors: Lydia E Volaitis, Joanne L MillerAbstract:In this investigation, the effects of context on the perception of voicing contrasts specified by voice‐onset‐time (VOT) in syllable‐initial stop consonants were examined. In an earlier paper [J. L. Miller and L. E. Volaitis, Percept. Psychophys. 46, 505–512 (1989)], it was reported that the listener’s adjustment for one contextual variable, speaking rate, was not confined to the region of the phonetic Category Boundary, but extended throughout the phonetic Category. The current investigation examines whether this type of perceptual remapping also occurs for another contextual variable, the place of articulation of the syllable‐initial consonant. In a preliminary experiment that involved acoustic measurement of natural speech, it was confirmed that as place of articulation moves from labial to velar, VOT increases, and it was established that this occurs across a range of speaking rates (syllable durations). In the main experiments, which focused on the voiceless Category, it was found that this acoustic ...
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Internal phonetic Category structure depends on multiple acoustic properties: Evidence for within‐Category trading relations
The Journal of the Acoustical Society of America, 1992Co-Authors: Philip Hodgson, Joanne L MillerAbstract:Two acoustic properties underlying the distinction between the presence and absence of a stop consonant, as in say vs stay, are silence duration and first‐formant (F1) onset frequency: little or no silence and a high F1 onset frequency specify say, whereas a longer silence and a lower F1 onset frequency specify stay. Previous research has established that these two properties enter into a trading relation at the phonetic Category Boundary. Whether they also enter into a trading relation within the Category is explored in the current investigation. Two series of stimuli having low (230 Hz) and high (430 Hz) F1 onset frequencies, respectively, have been created. Silence duration in each series varied from 0 to 996 ms, resulting in stimuli ranging from say through stay to an exaggerated version of stay. A preliminary two‐choice study (with just the stimuli between 0 and 136 ms) confirmed the expected trading relation at the say–stay Boundary, with the Boundary for the high F1 series being located at a longer...
Earl K Miller - One of the best experts on this subject based on the ideXlab platform.
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Pfc neurons reflect categorical decisions about ambiguous stimuli
Journal of cognitive neuroscience, 2014Co-Authors: Jefferson E. Roy, Timothy J. Buschman, Earl K MillerAbstract:We examined whether PFC neuron activity reflects categorical decisions in monkeys categorizing ambiguous stimuli. A morphing system was used to systematically vary stimulus shape and precisely define Category boundaries. Ambiguous stimuli were centered on a Category Boundary, that is, they were a mix of 50% of two prototypes and therefore had no Category information, so monkeys guessed at their Category membership. We found that the monkeys' trial-by-trial decision about the Category membership of an ambiguous image was reflected in PFC activity. Activity to the same ambiguous image differed significantly, depending on which Category the monkey had assigned it to. This effect only occurred when that scheme was behaviorally relevant. These indicate that PFC activity reflects categorical decisions.
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visual categorization and the primate prefrontal cortex neurophysiology and behavior
Journal of Neurophysiology, 2002Co-Authors: David J Freedman, Maximilian Riesenhuber, Tomaso Poggio, Earl K MillerAbstract:The ability to group stimuli into meaningful categories is a fundamental cognitive process. To explore its neuronal basis, we trained monkeys to categorize computer-generated stimuli as “cats” and “dogs.” A morphing system was used to systematically vary stimulus shape and precisely define a Category Boundary. Psychophysical testing and analysis of eye movements suggest that the monkeys categorized the stimuli by attending to multiple stimulus features. Neuronal activity in the lateral prefrontal cortex reflected the Category of visual stimuli and changed with learning when a monkey was retrained with the same stimuli assigned to new categories. Further, many neurons showed activity that appeared to reflect the monkey's decision about whether two stimuli were from the same Category or not. These results suggest that the lateral prefrontal cortex is an important part of the neuronal circuitry underlying Category learning and Category-based behaviors.
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categorical representation of visual stimuli in the primate prefrontal cortex
Science, 2001Co-Authors: David J Freedman, Maximilian Riesenhuber, Tomaso Poggio, Earl K MillerAbstract:The ability to group stimuli into meaningful categories is a fundamental cognitive process. To explore its neural basis, we trained monkeys to categorize computer-generated stimuli as “cats” and “dogs.” A morphing system was used to systematically vary stimulus shape and precisely define the Category Boundary. Neural activity in the lateral prefrontal cortex reflected the Category of visual stimuli, even when a monkey was retrained with the stimuli assigned to new categories.
Hans R Bosker - One of the best experts on this subject based on the ideXlab platform.
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accounting for rate dependent Category Boundary shifts in speech perception
Attention Perception & Psychophysics, 2017Co-Authors: Hans R BoskerAbstract:The perception of temporal contrasts in speech is known to be influenced by the speech rate in the surrounding context. This rate-dependent perception is suggested to involve general auditory processes because it is also elicited by nonspeech contexts, such as pure tone sequences. Two general auditory mechanisms have been proposed to underlie rate-dependent perception: durational contrast and neural entrainment. This study compares the predictions of these two accounts of rate-dependent speech perception by means of four experiments, in which participants heard tone sequences followed by Dutch target words ambiguous between /ɑs/ “ash” and /a:s/ “bait”. Tone sequences varied in the duration of tones (short vs. long) and in the presentation rate of the tones (fast vs. slow). Results show that the duration of preceding tones did not influence target perception in any of the experiments, thus challenging durational contrast as explanatory mechanism behind rate-dependent perception. Instead, the presentation rate consistently elicited a Category Boundary shift, with faster presentation rates inducing more /a:s/ responses, but only if the tone sequence was isochronous. Therefore, this study proposes an alternative, neurobiologically plausible account of rate-dependent perception involving neural entrainment of endogenous oscillations to the rate of a rhythmic stimulus.
Bruno H Repp - One of the best experts on this subject based on the ideXlab platform.
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Effects of preceding context on the voice-onset-time Category Boundary
Journal of experimental psychology. Human perception and performance, 1991Co-Authors: Bruno H Repp, Hwei-bing LinAbstract:The Category Boundary on a voice-onset-time (VOT) continuum ranging from bin to pin shifts when the stimuli are preceded by different carrier phrases. By using a variety of precursor phrases, by varying the temporal interval between precursor and test word, and by selectively eliminating either voicing information or spectral structure from the precursors, the present experiments show that the context effect is caused by the presence or absence of voicing in the precursor's final segment. The effect decreases with temporal separation but persists over several seconds. In addition, the "baseline" VOT Boundary for isolated test words interspersed in a test sequence shifts depending on what precursor stimuli occur in the same sequence. The perception of VOT thus seems to be sensitive to both close and distant manifestations of laryngeal activity, always in an assimilative fashion, which suggests an integrative perceptual mechanism with a long time constant. Language: en