Fovea And Side Effects Of The Foveal Vision Region Segmentation Information Representation

Objective:The study tried to use Chinese phontic compound characters to investigate the way to which the information was represented in foveal vision. The results of this study can provide the evidence to clarify which bilaterally projecting theory or split fovea theory was right. In addition, this study also tried to explore how to intergrate interhemispheric informations. Which early integration account or late integration account could reflect the nature of integration of interhemispheric informations.Methods:The experimental material is Chinese phontic compound characters. These Chinese characters are constituted of a dominant character structure exists in which a semantic radical appears on the left and a phonetic radical on the right (SP characters) and a minority opposite arrangement also exists (PS characters). These Chinse characters were classified into four categories by regularity and frequency: low-frequency and regular character\high-frequency and regular character\low-frequency and irregular character\high-frequency and irregular character. The experimental lused Chinese characters naming task. The experimental2used lexical decision task. In experimental1a and2a, Chinese characters (and pseudowords) were presented to the left or right of fixation, either close to fixation and entirely within foveal vision(<1°),or further from fixation and entirely within extrafoveal vision(>3°). The logic of this approach is that if word recognition is affected by a division in unilateral, contralateral hemispheric projections right up to the point of fixation, this division will be revealed by asymmetries in performance for words displayed to the left and right of fixation even when stimuli are displayed close to fixation and entirely within foveal vision. In ecperimental1b and2b, Chinese characters (and pseudowords) were presented to the center of fixation. The midpoint of phonetic radical and semantic radical precisely is located in the fixation. The purpose was insure that the each part of charcacters projected unilaterally and completely to contralateral hemisphere.Results:(1) The results of experimental1a indicated that, the results were similar between feveal vision and extrafoveal vision. PS characters showed that: under left visual field condition(LVF), the regularity effect was found for naming the high-frequency characters, and a reversed regularity effect was found for naming the low-frequency characters; under right visual field(RVF), high-frequency and low-frequency characters did not show regularity\reversed regularity effect. SP characters showed that:the regularity effect was found for naming the high-frequency characters in LVF and low-frequency characters in RVF;(2) The results of experimental lb revealed that, the regularity effect was found for naming the high-frequency PS characters, and a reversed regularity effect was found for naming the low-frequency PS characters; and the regularity effect was not found for naming the high-frequency SP characters, and the regularity effect was found for naming the low-frequency SP characters;(3) The results of experimental lb showed that, a right hemisphere(RH) advantage effect was found for PS and SP characters in foveal vision and extrafoveal vision;(4) The results of experimental lb displayed that, the regularity effect was found for the high-frequency PS characters, and the regularity effect was not found for the high-frequency SP characters; a reversed regularity effect was found for the low-frequency PS and SP characters.Conclusions:(1) The study provided clear evidence of a functional ivision in hemispheric processing for words displayed to the right and left of fixation in foveal locations. The SFT theory was right;(2) A RH advantage effect was found for orthographic processing. In characters naming task, a left hemisphere(LH) advantage effect was not found for phonological processing, but two hemispheres showed equal processing capability;3) The cerebral functional lateralization and frequency regulated together integration of interhemispheric informations. The regulatory mechanism showed that:In characters naming task, the processing of information is serviced by a distributed neural system, showing the early integration phenomenon. In lexical decision task, the processing of high-frequency characters might involve orthographic and phonological processing and also is serviced by a distributed neural system, showing the early integration phenomenon. The processing of low-frequency characters might mainly involve orthographic processing and is serviced by RH, showing the late integration phenomenon.