Darker, I.T., & Jordan, T.R. (2004). Perception of words and nonwords in the upper and lower visual fields. Brain and Language, 89, 593-600. (original) (raw)
Related papers
Perception of words and non-words in the upper and lower visual fields
Brain and Language, 2004
The findings of previous investigations into word perception in the upper and the lower visual field (VF) are variable and may have incurred non-perceptual biases caused by the asymmetric distribution of information within a word, an advantage for saccadic eye-movements to targets in the upper VF and the possibility that stimuli were not projected to the correct retinal locations. The present study used the Reicher-Wheeler task and an eye-tracker to show that, using stringent methodology, a right over left VF advantage is observed for word recognition, but that no differences were found between the upper and the lower VF for either word or non-word recognition. The results are discussed in terms of the neuroanatomy and perceptual abilities of the upper and the lower VF and implications for other studies of letter-string perception in the upper and the lower VF are presented.
Journal of Research in Reading, 2005
Some previous studies of visual word recognition have reported an interaction between visual field and word length (measured by number of letters), such that recognition is affected more by word length for words presented in the left than for words presented in the right visual field. However, when manipulating serial position of letters in words to measure length effects, there are also reports of symmetrical word length effects in the two visual fields. Here we report two experiments, presenting four-and seven-letter words, suggesting that the serial position and length effects in the hemispheres are separable and task dependent. For tasks that rely more heavily on letter-level processing such as letter search (Experiment 1), performance in both hemifields showed similar effects of serial position; however, when comparing four-and seven-letter words, an effect of word length was evident only in the left visual field, in line with the well-established interaction between word length and hemifield. An interaction between word length and hemifield was confirmed for the same stimuli when they were employed in a lexical decision task, which forced whole-word processing (Experiment 2). We conclude that the effects of serial position and number of letters in the two visual fields are separable, and are selectively affected by task type.
The role of eye movements in lateralised word recognition
Laterality: Asymmetries of Body, Brain and Cognition, 2006
The present study examined the role of eye movements and attention in lateralised word recognition, where words and pseudowords are presented to the right or left of the fixation point, and participants are asked to decide whether or not the presented letter string is a word. In the move condition, our participants were instructed to launch a saccade towards the target letter string, which was erased from the screen after 100 ms (i.e., prior to the eyes reaching the target). It was assumed that a preparation of an eye movement simultaneously with an attention shift results in the attention being more readily allocated to the target. In the fixate condition, participants were asked to fixate on the central fixation point throughout the trial. The data on response accuracy demonstrated that word recognition in the LVF benefited from a preparation to make an eye movement, whereas the performance in the RVF did not benefit. The results are consistent with the attentional advantage account (Mondor & Bryden, 1992), according to which the performance deficit of RH for verbal stimuli may be overcome by orienting attention to the LVF prior to the presentation of a letter string.
Visual field differences in recognizing letters
Perception & Psychophysics, 1976
Differences due to visual field location were examined for single letters placed at one of 12 dockface positions 3°and 6°from fixation. Results compared closely with established findings using simple light stimuli, showing best recognition on the horizontal meridian, poorest on the vertical and intermediate on oblique meridians. Subjects' confidence ratings followed the same pattern. There was evidence for a specific right superiority along the horizontal meridian, as found in previous studies, but no evidence for a general right hemifield superiority. The difficulty of arguing from these findings to available dominance or scanning explanations is pointed out. It is proposed that effects due to visual field variability may have a pervasive yet largely unrecognized influence in visual perception research.