Search Results

This chapter discusses how reprogramming the brain, by inducing visual inputs to innervate the auditory pathway, can reveal the relative influence of intrinsic and extrinsic factors in determining the function and organization of sensory cortex and thalamic nuclei. It describes its effect on retinal innervation, its physiological and behavioral consequences, and its potential influence on cortical circuitry.

This chapter discusses reading, which is a language process that always begins as a visual process. It is also a secondary language process, a derivative of primary spoken language processes. The discussion takes a look at three general processing phases in order to gain better understanding of this language process. The first is the visual, the second is the processes that convert the visual input into something else, and the third is the processes that then operate on the encoded representation.

Visual input is processed in parallel in the early stages of the visual system. Later, object recognition processes are also massively parallel, matching a visual object with a vast array of stored representation. A tight bottleneck in processing lies between these stages. It permits only one or a few visual objects at any one time to be submitted for recognition. That bottleneck limits performance on visual search tasks when an observer looks for one object in a field containing distracting objects. Guided Search is a model of the workings of that bottleneck. It proposes that a limited set of attributes, derived from early vision, can be used to guide the selection of visual objects. The bottleneck and recognition processes are modeled using an asynchronous version of a diffusion process. The current version (Guided Search 4.0) captures a range of empirical findings.

Many everyday tasks require us to perform a visual search. Therefore, an adequate model of visual search is an indispensable part of any plausible approach to modeling integrated cognitive systems that process visual input. Because of its quantitative nature, an absence of freely adjustable parameters, and support from empirical research results, the area activation model is presented as a promising starting point for developing such a model. Its basic assumption is that eye movements in visual search tasks tend to target display areas that provide a maximum amount of task-relevant information for processing. This chapter reports the results of a study that tackles the shortcomings of the current model and provides a variety of quantitative data on saccadic selectivity in the visual search. It discusses how these and related data will be used to develop the area activation model toward a general model of eye movements in visual search.