Borsky S, Tuller B, Shapiro L P
Program in Complex Systems and Brain Sciences, Florida Atlantic University, Boca Raton 33431, USA.
J Acoust Soc Am. 1998 May;103(5 Pt 1):2670-6. doi: 10.1121/1.422787.
This study examined the effect of sentence context and local acoustic structure on phoneme categorization. Target stimuli from a 10-step GOAT-COAT continuum, differing only on a temporal cue for voice onset time (VOT), were embedded in carrier sentences that biased interpretation toward either "goat" or "coat." While subjects listened to the sentences they also responded as quickly as possible to a visual probe by indicating whether the probe matched the target stimulus they heard. Results showed that the interaction of VOT and sentence context significantly affected both identification and RT for stimuli near the perceptual boundary; the identification function showed a boundary shift in favor of the biased context and peak response times for each context reflected the shifted identification boundaries. In addition, response times were faster for identification of stimuli near the category boundary when responses were congruent, rather than incongruent with the sentence context. The response time differences for congruent versus incongruent responses in the boundary region are interpreted as depending on the results of initial phonological analysis; potentially ambiguous categorizations may be subject to additional evaluation in which a context-congruent response is both preferred and available earlier.
本研究考察了句子语境和局部声学结构对音素分类的影响。来自10步“山羊-外套”连续体的目标刺激，仅在语音起始时间（VOT）的时间线索上有所不同，被嵌入到偏向于“山羊”或“外套”解释的载体句子中。当受试者听句子时，他们也会通过指出视觉探针是否与他们听到的目标刺激相匹配，尽可能快地对视觉探针做出反应。结果表明，VOT和句子语境的相互作用显著影响了接近感知边界的刺激的识别和反应时间；识别函数显示出偏向于有偏向语境的边界偏移，每个语境的峰值反应时间反映了偏移的识别边界。此外，当反应与句子语境一致而非不一致时，对接近类别边界的刺激进行识别的反应时间更快。边界区域中一致反应与不一致反应的反应时间差异被解释为取决于初始语音分析的结果；潜在的模糊分类可能会受到额外的评估，在这种评估中，与语境一致的反应既更受青睐，又能更早获得。
