The presented study examines the question of colour categorization in relation to the hypothesis of linguistic relativity. The study is based on research conducted by Gilbert et al. (2006) and their claim that linguistic colour categorization in a particular language helps colour recognition and speeds the process of colour discrimination for…

It has been recently argued that some machine learning techniques known as Kernel methods could be relevant for capturing cognitive and neural mechanisms (Jakel, Scholkopf, & Wichmann, 2009). We point out that "String kernels," initially designed for protein function prediction and spam detection, are virtually identical to one contending proposal…

Category training can induce category effects, whereby color discrimination of stimuli spanning a newly learned category boundary is enhanced relative to equivalently spaced stimuli from within the newly learned category (e.g., categorical perception). However, the underlying mechanisms of these acquired category effects are not fully understood.…

The author briefly responds to a number of terminological, theoretical, and empirical issues raised in some postscripts. The goal is not to respond to each outstanding point but rather to address some comments that in his view confuse rather than clarify matters. He responds to Plaut and McClelland and Quian Quiroga and Kreiman in turn.

Categorical perception (CP) is said to occur when a continuum of equally spaced physical changes is perceived as unequally spaced as a function of category membership (Harnad, S. (Ed.) (1987). Psychophysical and cognitive aspects of categorical perception: A critical overview. Cambridge: Cambridge University Press). A common suggestion is that CP…

The type of visual information needed for categorizing faces and nonface objects was investigated by manipulating spatial frequency scales available in the image during a category verification task addressing basic and subordinate levels. Spatial filtering had opposite effects on faces and airplanes that were modulated by categorization level. The…

The processes of overall similarity sorting were investigated in 5 free classification experiments. Experiments 1 and 2 demonstrated that increasing time pressure can reduce the likelihood of overall similarity categorization. Experiment 3 showed that a concurrent load also reduced overall similarity sorting. These findings suggest that overall…

Background: Impaired face processing is a widely documented deficit in autism. Although the origin of this deficit is unclear, several groups have suggested that a lack of perceptual expertise is contributory. We investigated whether individuals with autism develop expertise in visuoperceptual processing of faces and whether any deficiency in such…

Previous research suggests that model competence does not emerge until relatively late in infancy (20-26 months). Development was systematically analyzed within 3 key areas--count noun learning, dual representation, and categorization--hypothesized to support the emergence of model competence in the second year. In an object-handling preferential…

The effects of familiarity on selective attention for the identity and expression of faces were tested using Garner's speeded-classification task. In 2 experiments, participants classified expression (or identity) of familiar and unfamiliar faces while the irrelevant dimension of identity (or expression) was either held constant (baseline…

A successful vision system must solve the problem of deriving geometrical information about three-dimensional objects from two-dimensional photometric input. The human visual system solves this problem with remarkable efficiency, and one challenge in vision research is to understand how neural representations of objects are formed and what visual…

Eighteen healthy young adults underwent event-related (ER) functional magnetic resonance imaging (fMRI) of the brain while performing a visual category learning task. The specific category learning task required subjects to extract the rules that guide classification of quasi-random patterns of dots into categories. Following each classification…

The efficacy of gating in the processing of simple, multidimensional stimuli was investigated. In Experiment 1, a continuous classification task was used, with subjects sorting cards according to binary dimensions of line orientation and location. Results suggested that orientation and location are integral dimensions, facilitation occurring with…

Children often perseverate, repeating prior behaviors when inappropriate. This work tested the roles of verbal labels and stimulus novelty in such perseveration. Three-year-old children sorted cards by one rule and were then instructed to switch to a second rule. In a basic condition, cards had familiar shapes and colors and both rules were stated…

Reviews the research literature on the abilities of infants to categorize visual information on dot patterns; schematic faces; hue; and orientation. (HOD)