Perceptual expertise improves category detection in natural scenes

There is much debate about how detection, categorization, and within-category identification relate to one another during object recognition. Whether these tasks rely on partially shared perceptual mechanisms may be determined by testing whether training on one of these tasks facilitates performance on another. In the present study we asked whether expertise in discriminating objects improves the detection of these objects in naturalistic scenes. Self-proclaimed car experts (N = 34) performed a car discrimination task to establish their level of expertise, followed by a visual search task where they were asked to detect cars and people in hundreds of photographs of natural scenes. Results revealed that expertise in discriminating cars was strongly correlated with car detection accuracy. This effect was specific to objects of expertise, as there was no influence of car expertise on person detection. These results indicate a close link between object discrimination and object detection performance, which we interpret as reflecting partially shared perceptual mechanisms and neural representations underlying these tasks: the increased sensitivity of the visual system for objects of expertise – as a result of extensive discrimination training – may benefit both the discrimination and the detection of these objects. Alternative interpretations are also discussed

Oculographic Analysis of Word Reading in Hemispatial Neglect

Neglect dyslexia is a disorder in which individuals misread text appearing on the contralateral side of space following an acquired lesion, usually to the right parietal lobe. This disorder is generally attributed to an impairment in representing spatial information. To determine whether the spatial representations underlying reading differ from those mediating other forms of visual behavior, we investigated the cooccurrence of neglect dyslexia with that of neglect, which manifests on tasks such as line bisection or line cancellation. We also examined the correlation between neglect dyslexia, when present, and eye movements in order to characterize the neglect dyslexia disorder further. Whereas there is no clear relationship between the reading disorder and other symptoms of visuospatial neglect, suggesting segregated spatial representations, there is a direct correspondence between the oculomotor performance of patients with neglect dyslexia and their reading behavior. This latter result suggests that the reading deficit may well arise from the failure to register and perceive the contralesional information

Age-Dependent Face Detection and Face Categorization Performance

Empirical studies on the development of face processing skills with age show inconsistent patterns concerning qualitative vs. quantitative changes over time or the age range for peak cognitive performance. In the present study, we tested the proficiency in face detection and face categorization with a large sample of participants (N = 312; age range: 2-88 yrs). As test objects, we used so-called Mooney faces, two-tone (black and white) images of faces lacking critical information of a local, featural and relational nature, reflecting difficult real world face processing conditions. We found that performance in the assessment of gender and age from Mooney faces increases up to about age 15, and decreases from 65 years on. The implications of these findings are discussed in the light of classic and recent findings from face development literature