Loss of high-level perceptual knowledge of object structure in DAT

Peer reviewe

Change blindness: eradication of gestalt strategies

Arrays of eight, texture-defined rectangles were used as stimuli in a one-shot change blindness (CB) task where there was a 50% chance that one rectangle would change orientation between two successive presentations separated by an interval. CB was eliminated by cueing the target rectangle in the first stimulus, reduced by cueing in the interval and unaffected by cueing in the second presentation. This supports the idea that a representation was formed that persisted through the interval before being 'overwritten' by the second presentation (Landman et al, 2003 Vision Research 43149–164]. Another possibility is that participants used some kind of grouping or Gestalt strategy. To test this we changed the spatial position of the rectangles in the second presentation by shifting them along imaginary spokes (by ±1 degree) emanating from the central fixation point. There was no significant difference seen in performance between this and the standard task [F(1,4)=2.565, p=0.185]. This may suggest two things: (i) Gestalt grouping is not used as a strategy in these tasks, and (ii) it gives further weight to the argument that objects may be stored and retrieved from a pre-attentional store during this task

Both symbolic and embodied representations contribute to spatial language processing: Evidence from younger and older adults

Building on earlier neuropsychological work, we adopted a novel individual differences approach to examine the relationship between spatial language and a wide range of both verbal and nonverbal abilities. Three new measures were developed for the assessment of spatial language processing: spatial naming, spatial verbal memory, and verbal comprehension in spatial perspective taking. Results from a sample of young adults revealed significant correlations between performance on the spatial language tasks and performance on both the analogous (non-spatial) verbal measures as well as on the (non-verbal) visual-spatial measures. Visual-spatial abilities, however, were more predictive of spatial language processing than verbal abilities. Furthermore, results from a sample of older adults revealed impairments in visual-spatial tasks and on spatial verbal memory. The results support dual process accounts of meaning, and provide further evidence of the close connection between the language of space and non-linguistic visual-spatial cognition

Fine-Scale Spatial Organization of Face and Object Selectivity in the Temporal Lobe: Do Functional Magnetic Resonance Imaging, Optical Imaging, and Electrophysiology Agree?

The spatial organization of the brain's object and face representations in the temporal lobe is critical for understanding high-level vision and cognition but is poorly understood. Recently, exciting progress has been made using advanced imaging and physiology methods in humans and nonhuman primates, and the combination of such methods may be particularly powerful. Studies applying these methods help us to understand how neuronal activity, optical imaging, and functional magnetic resonance imaging signals are related within the temporal lobe, and to uncover the fine-grained and large-scale spatial organization of object and face representations in the primate brain