Allophonic mode of speech perception in dyslexia

Perceptual discrimination between speech sounds belonging to different phoneme categories is better than that between sounds falling within the same category. This property, known as "categorical perception," is weaker in children affected by dyslexia. Categorical perception develops from the predispositions of newborns for discriminating all potential phoneme categories in the world's languages. Predispositions that are not relevant for phoneme perception in the ambient language are usually deactivated during early childhood. However, the current study shows that dyslexic children maintain a higher sensitivity to phonemic distinctions irrelevant in their linguistic environment. This suggests that dyslexic children use an allophonic mode of speech perception that, although without straightforward consequences for oral communication, has obvious implications for the acquisition of alphabetic writing. Allophonic perception specifically affects the mapping between graphemes and phonemes, contrary to other manifestations of dyslexia, and may be a core deficit.     

Effects of the global and local attention on the processing of categorical and coordinate spatial relations

Participants made categorical or coordinate spatial judgments on the global or local elements of shapes. Stimuli were composed of a horizontal line and two dots. In the Categorical task, participants judged whether the line was above or below the dots. In the Coordinate task, they judged whether the line would fit between the dots. Stimuli were made hierarchical so that the global patterns composed of a “global line” made of local dots-and-line units, and “global dot” made of a single dots-and-line unit. The results indicated that the categorical task was better performed when participants attended to the local level of the hierarchical stimuli. On the other hand, the coordinate task was better performed when they attended to the global level. These findings are consistent with computer simulation models of the attentional modulation of neuronal receptive fields’ size suggesting that (1) coordinate spatial relations are more efficiently encoded when one attends to a relatively large region of space, whereas (2) categorical spatial relations are more efficiently encoded when one attends to a relatively small region of space.     

Naturalism and the Space of Reasons in Mind and World

Abstract

This paper aims to show that many criticisms of McDowell’s naturalism of second nature are based on what I call ‘the orthodox interpretation’ of McDowell’s naturalism. The orthodox interpretation is, however, a misinterpretation, which results from the fact that the phrase ‘the space of reasons’ is used equivocally by McDowell in Mind and World. Failing to distinguish two senses of ‘the space of reasons’, I argue that the orthodox interpretation renders McDowell’s naturalism inconsistent with McDowell’s Hegelian thesis that the conceptual is unbounded. My interpretation saves McDowell from being inconsistent. However, the upshot of my interpretation is that what is really at work in McDowell’s diagnosis of the dualism between nature and reason is the Hegelian thesis, not the naturalism of second nature.     

Spectral information in nonspeech contexts influences children’s categorization of ambiguous speech sounds

For both adults and children, acoustic context plays an important role in speech perception. For adults, both speech and nonspeech acoustic contexts influence perception of subsequent speech items, consistent with the argument that effects of context are due to domain-general auditory processes. However, prior research examining the effects of context on children’s speech perception have focused on speech contexts; nonspeech contexts have not been explored previously. To better understand the developmental progression of children’s use of contexts in speech perception and the mechanisms underlying that development, we created a novel experimental paradigm testing 5-year-old children’s speech perception in several acoustic contexts. The results demonstrated that nonspeech context influences children’s speech perception, consistent with claims that context effects arise from general auditory system properties rather than speech-specific mechanisms. This supports theoretical accounts of language development suggesting that domain-general processes play a role across the lifespan.     

Individuals with Autism can Categorize Facial Expressions

The ability of high-functioning individuals with autism to perceive facial expressions categorically was studied using eight facial expression continua created via morphing software. Participants completed a delayed matching task and an identification task. Like undergraduate male participants (N = 12), performance on the identification task for participants with autism (N = 15) was predicted by performance on the delayed matching task for the angry-afraid, happy-sad, and happy-surprised continua. This result indicates a clear category boundary and suggests that individuals with autism do perceive at least some facial expressions categorically. As this result is inconsistent with findings from other studies of categorical perception in individuals with autism, possible explanations for these findings are discussed.     

Measuring anxiety by ordered categorical items in data with subgroup structure: the case of the Hungarian version of the trait anxiety scale of the state-trait anxiety inventory for children (staic-h)

The present study suggests a modelling methodology for examining measurement invariance of ordered categorical item indicators of latent constructs such as anxiety, coping, motives etc., in research settings with few subgroups and a large sample of individuals. The Hungarian version of the Anxiety Trait scale of the State-Trait Anxiety Inventory for Children (STAIC-H) was administered to 605 boys and 975 girls of age 10–15 in 12 schools. A MIMIC model was suggested for examining measurement invariance across subgroups of schools and ages, while a multi-group analysis was recommended for investigating invariance across gender. High degree of invariance across groups was obtained for the Anxiety Trait scale in terms of item factor loadings, item thresholds and item homogeneity with respect to group contrast variables. Based on the diagnostic information obtained by the present methodology, the few item indicators showing non-invariance were discussed with reference to methodological and conceptual considerations.     

Searching through the hierarchy: How level of target categorization affects visual search

Does the same basic-level advantage commonly observed in the categorization literature also hold for targets in a search task? We answered this question by first conducting a category verification task to define a set of categories showing a standard basic-level advantage, which we then used as stimuli in a search experiment. Participants were cued with a picture preview of the target or its category name at either superordinate, basic, or subordinate levels, then shown a target-present/absent search display. Although search guidance and target verification was best using pictorial cues, the effectiveness of the categorical cues depended on the hierarchical level. Search guidance was best for the specific subordinate-level cues, whereas target verification showed a standard basic-level advantage. These findings demonstrate different hierarchical advantages for guidance and verification in categorical search. We interpret these results as evidence for a common target representation underlying categorical search guidance and verification.     

Coding categorical and coordinate spatial relations in visual–spatial short-term memory

Four experiments explored the coding of categorical and coordinate spatial relations in visual–spatial short-term memory (VSSTM). Participants judged whether two stimuli presented successively on a computer screen were the same or different. On positional change trials the two stimuli differed in the position of one element. Positional changes were of two types, coordinate and categorical. On coordinate trials the position of one element changed by a small amount, but retained the categorical relationships (above, below, left of, right of) to all other elements. On categorical trials one element moved by the same amount but additionally changed its categorical relationship to one of the other elements (e.g., changed from below to above). Participants detected categorical changes more accurately than coordinate changes when the elements were independent locations marked by squares, indicating that the categorical relationships amongst the squares were encoded in memory. Furthermore, this categorical advantage was unmodulated by either the suppression of articulation (Experiment 2) or by the requirement to retain either colour–position associations or positions only (Experiment 3). When the elements to be remembered were the vertices of simple outline polygons (Experiment 4) there was no categorical advantage, establishing the effect as spatial in nature. Contrary to predictions derived from Postma and De Haan (1996) Postma, A. and De Haan, E. H. 1996. What was where? Memory for object locations. Quarterly Journal of Experimental Psychology, 49A: 178–199. [Crossref], [Web of Science ®] , [Google Scholar], the employment of categorical relations appears not to be specifically linked to either verbal coding or to the requirement to associate objects with positions. The results suggest that the categorical relations are an intrinsic property of the representation of spatial configurations.     

Perceptual and categorical judgements of colour similarity

Consideration is given to the tasks that make judgements of colour similarity based on perceptual similarity rather than categorical similarity. Irrespective of whether colour categories are taken to be universal (Berlin & Kay, 1969) or language induced (Davidoff, Davies, & Roberson, 1999), it is widely assumed that colour boundaries, and hence categorical similarity, would be used when categorising colours. However, we argue that categorical similarity is more reliably used in implicit than in explicit categorisation. Thus, in Experiment 1, we found that category boundaries may be overridden in the explicit task of matching-to-sample: There was a similar strong tendency to ignore colour boundaries and to divide the range of coloured stimuli into two equal groups in both Westerners and in a remote population (Himba). In Experiment 2, we showed that a distinctive stimulus (focal colour) in the range affected the equal division in a matching-to-sample task. Experiment 3 tested the stability of a category boundary in an implicit task (visual search) that assessed categorical perception; only for this task was categorisation largely immune to range effects and largely based on categorical similarity. It is concluded that, even after colour categories are acquired, perceptual rather than categorical similarity is commonly used in judgements of colour similarity.