Tactile picture recognition by early blind children: the effect of illustration technique.

This study investigated factors that influenced haptic recognition of tactile pictures by early blind children. Such a research is motivated by the difficulty to identify tactile pictures, that is, two-dimensional representations of objects, while it is the most common way to depict the surrounding world to blind people. Thus, it is of great interest to better understand whether an appropriate representative technique can make objects' identification more effective and to what extent a technique is uniformly suitable for all blind individuals.

Lexical references to sensory modalities in verbal descriptions of people and objects by congenitally blind, late blind and sighted adults.

Background: Some previous studies have revealed that while congenitally blind people have a tendency to refer to visual attributes ('verbalism'), references to auditory and tactile attributes are scarcer. However, this statement may be challenged by current theories claiming that cognition is linked to the perceptions and actions from which it derives. Verbal productions by the blind could therefore differ from those of the sighted because of their specific perceptual experience.

The haptic recognition of geometrical shapes in congenitally blind and blindfolded adolescents: is there a haptic prototype effect?

Background: It has been shown that visual geometrical shape categories (rectangle and triangle) are graded structures organized around a prototype as demonstrated by perception and production tasks in adults as well as in children. The visual prototypical shapes are better recognized than other exemplars of the categories. Their existence could emerge from early exposure to these prototypical shapes that are present in our visual environment.

Effects of peripheral and central visual impairment on mental imagery capacity.

This paper reviews a number of behavioral, neuropsychological and neuroimaging studies that bear on the question of whether and how visual disorders of peripheral or central origin lead to disorders of mental imagery capacity. The review of the literature suggests that in cases of blindness of peripheral origin lack of vision can progressively lead to representational disorders. However, in patients suffering from peripheral visual deficits, representational disorders can partially or completely be compensated by other sensory modalities as well as by cortical reorganization.

Geometrical haptic illusions: the role of exploration in the Müller-Lyer, vertical-horizontal, and Delboeuf illusions.

This article surveys studies of the occurrence, in the haptic modality, of three geometrical illusions well known in vision, and it discusses the nature of the processes underlying these haptic illusions. We argue that the apparently contradictory results found in the literature concerning them may be explained, at least partially, by the characteristics of manual exploratory movements. The Müller-Lyer illusion is present in vision and in haptics and seems to be the result of similar processes in the two modalities.