Perceptual load as a major determinant of the locus of selection in visual attention

In this paper, we propose that the debate concerning the locus of attentional selection can be resolved by specifying the conditions under which early selection is possible. In the first part, we present a theoretical discussion that integrates aspects from structural and capacity approaches to attention and suggest that perceptual load is a major factor in determining the locus of selection. In the second part, we present a literature review that examines the conditions influencing the processing of irrelevant information. This review supports the conclusion that a clear physical distinction between relevant and irrelevant information is not sufficient to prevent irrelevant processing; early selection also requires that the perceptual load of the task be sufficiently high to exceed the upper limit of available attentional resources.     

Auditory coding of visual patterns for the blind

Recognition tasks of simple visual patterns have been used to assess an early visual--auditory sensory-substitution system, consisting of the coupling of a rough model of the human retina with an inverse model of the cochlea, by means of a pixel-frequency relationship. The potential advantage of the device, compared with previous ones, is to give the blind the ability to both localise and recognise visual patterns. Four evaluation sessions assessed the performance of twenty-four blindfolded sighted subjects using the device. Subjects had to recognise twenty-five visual patterns, one at a time, using a head-mounted small camera and interpreting the corresponding sounds given by the device. Half the subjects were trained by means of a correction feedback procedure during ten one-hour training sessions embedded in between the evaluation sessions. Results revealed extremely successful training effects. Performance of trained subjects significantly increased with practice compared with the untrained control group. The improvement was also observed for new patterns, demonstrating a learning-process generalisation. The negative correlation observed between scores and processing time showed that the subjects' response accuracy was related to their speed. In conclusion, simple pattern recognition is possible with a fairly natural vision-to-audition coding scheme, given the possibility for the subjects to have sensory--motor interactions while using the device.     

Auditory and visual factors of intelligence

In a sample of 241 convicts, most of whom were between 20 and 35 years of age, a sample of 18 primary mental abilities was factored to explore the idea that in performances that are believed to indicate human intelligence there are organizations among visual and auditory functions that operate independently from the relation-perceiving and correlate-educing functions of fluid and crystallized intelligence. Objectively rotated results suggest that, indeed, reliable overlapping (common-factor) functions of Auditory Acuity (Ac), Auditory Organization (Ga), Visual Organization (Gv), Acculturational Eduction (Gc) and Fluid Eduction (Gf) represent separate components of individual differences in performances on intellectual tasks broadly conceived.