We intended to establish if two lexical tone contrasts in Zhumadian Mandarin, one between early and late aligned falls and another between early and late aligned rises, are perceived categorically, while the difference between declarative and interrogative pronunciations of these four tones is perceived gradiently. Presenting stimuli from 7-point acoustic continua between tones and between intonations, we used an identification task and a discrimination task with an experimental group of native listeners and a control group of Indonesian listeners, whose language employs none of the differences within either the falling or the rising pitch contours in its phonology. Only the lexical condition as perceived by the experimental group yielded sigmoid identification functions and a heightened discriminatory sensitivity around the midpoint of continua. The intonational condition in the native group and both conditions in the control group yielded gradient identification functions and smaller, reverse effects of the continuum midpoints in the discrimination task. The results are interpreted to mean that sentence modality contrasts can be expressed gradiently, but that lexical tone differences are represented phonologically, and hence are perceived categorically, despite low phonetic salience of the contrast. This conclusion challenges assumptions about the relation between linguistic functions and linguistic structures.

Emotional and interpersonal difficulties have been widely described in alcohol-dependence [1] and are thought to play a crucial role in the development and maintenance of this disease [2]. In particular, impairments in the decoding of emotional facial expression (EFE) have been repeatedly reported and may have serious deleterious effects for the everyday life of alcohol-dependent individuals (ADI), notably by affecting their interpersonal relationships [3]. However, the large majority of earlier studies that assessed emotional decoding abilities among ADI were interested in the processing of prototypical full-blown EFE while in everyday social life, EFE are usually not entirely straightforward but are rather composed of a mix of different emotions [4]. The aim of this study was therefore to determine whether ADI exhibit the categorical perception effect, which is a critical process observed in healthy populations to efficiently decode ambiguous EFE. Nineteen recently detoxified ADI and 19 healthy controls (HC), matched for age and gender, were presented with facial stimuli depicting [4] EFE (happy, angry, sad, and neutral), morphed along continua between each possible pair of emotions. Participants had to indicate the predominant emotion within the randomly presented facial stimuli. For each EFE, a sigmoid function that estimated the percentage of identifications according to the morph steps was adjusted for each participant's data. While there was no significant group difference regarding the response slope (indicating how abruptly the shift in responses happens), the identification threshold (i.e. the function midpoint) was significantly increased in ADI compared to HC, independently of the EFE category. The categorical perception of EFE per se appeared thus preserved in alcohol-dependence, but ADI exhibited a bias in EFE decoding characterized by a global under-identification. To conclude, this study is the first to evidence an EFE processing deficit in ADI by using this kind of emotional continuum paradigm measuring the categorical perception effect.

This study examines brain responses to boundary effects with respect to Mandarin lexical tone continua for three groups of adult listeners: (1) native English speakers who took advanced Mandarin courses; (2) naïve English speakers; and (3) native Mandarin speakers. A cross-boundary tone pair and a within-category tone pair derived from tonal contrasts (Mandarin Tone 1/Tone 4; Tone 2/Tone 3) with equal physical/acoustical distance were used in an auditory oddball paradigm. For native Mandarin speakers, the cross-category deviant elicited a larger MMN over left hemisphere sensors and larger P300 responses over both hemispheres relative to within-category deviants, suggesting categorical perception of tones at both pre-attentive and attentional stages of processing. In contrast, native English speakers and Mandarin learners did not demonstrate categorical effects. However, learners of Mandarin showed larger P300 responses than the other two groups, suggesting heightened sensitivity to tones and possibly greater attentional resource allocation to tone identification.

Sign languages like British Sign Language (BSL) include partially lexicalized constructions depicting object handling or manipulation – handling constructions. Object sizes gradiently vary, yet it is unclear whether handling handshapes depict handled objects categorically or gradiently. This study investigates the influence of sign language experience on perception of handling handshapes. Deaf signers and hearing non-signers completed perceptual handshape identification and discrimination tasks. We examined whether deaf BSL signers perceived handshape continua categorically or continuously compared with hearing non-signers, and whether reaction times were modulated by linguistic representations. The results revealed similar binary categorization of dynamically presented handling handshapes as deaf and hearing perceivers displayed higher discrimination accuracy on category boundaries, and lower, but above chance, within-category discrimination, suggesting that perceptual categorization was not uniquely mediated by linguistic experience. However, RTs revealed critical differences between groups in processing times; deaf signers’ RTs reflected stronger category bias and increased sensitivity to boundaries, suggesting underlying linguistic representations. Further, handshape variability within categories influenced deaf signers’ discrimination RTs in a manner that suggested graded category organization, with handshape prototype grounding the category. These findings provide an insight into the internal organization of handling handshapes and highlight the complex relationship between sign language, cognition, and gesture.

We report psychophysical evidence for a categorical dichotomy in the perception of contrast. Observers were required to rate the contrast of sinusoidal gratings (2.3 c/d) with contrast varying over a given range relative to two standards. One standard was designated “high” contrast and the other was designated “low.” There was a boundary effect: contrast judgment depended upon whether the tested ranges included 10–15% contrast and discrimination was sharpest at the boundary between 10 and 15% contrast. These results are consistent with the existence of two systems underlying perceived contrast; one primarily sensitive below 10%, and the other primarily sensitive above 15% contrast.

Although the study of visual perception has made more progress in the past 40 years than any other area of cognitive science, there remain major disagreements as to how closely vision is tied to cognition. This target article sets out some of the arguments for both sides (arguments from computer vision, neuroscience, psychophysics, perceptual learning, and other areas of vision science) and defends the position that an important part of visual perception, corresponding to what some people have called early vision, is prohibited from accessing relevant expectations, knowledge, and utilities in determining the function it computes – in other words, it is cognitively impenetrable. That part of vision is complex and involves top-down interactions that are internal to the early vision system. Its function is to provide a structured representation of the 3-D surfaces of objects sufficient to serve as an index into memory, with somewhat different outputs being made available to other systems such as those dealing with motor control. The paper also addresses certain conceptual and methodological issues raised by this claim, such as whether signal detection theory and event-related potentials can be used to assess cognitive penetration of vision.

A distinction is made among several stages in visual processing, including, in addition to the inflexible early-vision stage, a pre-perceptual attention-allocation stage and a post-perceptual evaluation, selection, and inference stage, which accesses long-term memory. These two stages provide the primary ways in which cognition can affect the outcome of visual perception. The paper discusses arguments from computer vision and psychology showing that vision is “intelligent” and involves elements of “problem solving.” The cases of apparently intelligent interpretation sometimes cited in support of this claim do not show cognitive penetration; rather, they show that certain natural constraints on interpretation, concerned primarily with optical and geometrical properties of the world, have been compiled into the visual system. The paper also examines a number of examples where instructions and “hints” are alleged to affect what is seen. In each case it is concluded that the evidence is more readily assimilated to the view that when cognitive effects are found, they have a locus outside early vision, in such processes as the allocation of focal attention and the identification of the stimulus.