Abnormal optokinetic and perceptual span parameters in cerebellar-vestibular dysfunction and learning disabilities or dyslexia

To measure the ocular fixation and sequential scanning dysfunction assumed responsible for the visual reading symptoms which characterize dyslexia or learning disabilities, an optokinetically based tracking method was devised. This method quantitatively demonstrated significantly reduced fixation, tracking, and perceptual or visual-span scores as well as "movement illusions" for 70 cerebellar-vestibular dysfunctioning persons with learning disabilities vs 70 controls. Such data tended to validate the hypothesis that cerebellar-vestibular-determined fixation and tracking mechanisms predispose dyslexic or learning disabled individuals to visual reading disorders. Moreover, a newly revised method is presented which may prove useful in rapidly screening and diagnosing cerebellar-vestibular-determined reading and learning disorders from those of other origins. Additional independent studies using significantly larger samples and asymptomatic or "normal" controls are required for further validation and development of the method.     

The role of glutamate in anxiety and related disorders

Anxiety, stress, and trauma-related disorders are a major public health concern in the United States. Drugs that target the gamma-aminobutyric acid or serotonergic system, such as benzodiazepines and selective serotonin reuptake inhibitors, respectively, are the most widely prescribed treatments for these disorders. However, the role of glutamate in anxiety disorders is becoming more recognized with the belief that drugs that modulate glutamatergic function through either ionotropic or metabotropic glutamate receptors have the potential to improve the current treatment of these severe and disabling illnesses. Animal models of fear and anxiety have provided a method to study the role of glutamate in anxiety. This research has demonstrated that drugs that alter glutamate transmission have potential anxiolytic action for many different paradigms including fear-potentiated startle, punished responding, and the elevated plus maze. Human clinical drug trials have demonstrated the efficacy of glutamatergic drugs for the treatment of obsessive-compulsive disorder, posttraumatic stress disorder, generalized anxiety disorder, and social phobia. Recent data from magnetic resonance imaging studies provide an additional link between the glutamate system and anxiety. Collectively, the data suggest that future studies on the mechanism of and clinical efficacy of glutamatergic agents in anxiety disorders are appropriately warranted.     

The perceptual span and peripheral cues in reading

Skilled readers read passages that were displayed on a Cathode Ray Tube controlled by a computer. The readers' eye movements were monitored and certain critical words were changed by the computer as the eye was in motion. The experimental technique utilized in the study provided data on how wide the area is from which a reader acquires information during a fixation in silent reading. The results also delineate different types of visual information that are acquired from various areas within the perceptual span. It was found that a reader was able to make a semantic interpretation of a word that began 1–6 character spaces from his fixation point. When he fixated 7–12 character spaces prior to a word, he was able to pick up such gross visual characteristics as word shape and initial and final letters. It was concluded that the skilled reader is able to take advantage of information in the periphery. However, the size of the area from which he does is rather small.     

Processing efficiency in preschoolers’ memory span: Individual differences related to age and anxiety

In self-paced auditory memory span tasks, the microanalysis of response timing measures represents a developmentally sensitive measure, providing insights into the development of distinct processing rates during recall performance. The current study first examined the effects of age and trait anxiety on span accuracy (effectiveness) and response timing (efficiency) measures from word and digit span performance in a preschool sample (N = 76, mean age = 57 months, SD = 11). Children were reassessed 8 months later using the same two tasks plus a test of nonword memory span and a measure of articulation rate. The results at the second time point (T2) confirmed the effects of age on both processing effectiveness and efficiency. Trait anxiety was an additional negative predictor of span effectiveness (especially for digit span) and efficiency (in the case of word and nonword span). The findings are discussed in the context of factors contributing to early short-term memory development and attentional control theory.     

Asymmetries in the perceptual span for Israeli readers

Native Israeli readers read Hebrew and English text as their eye movements were monitored. A window of text moved in synchrony with their eye movements and the window was either symmetrical about the fixation point or offset to the left or right. When subjects were reading Hebrew, the perceptual span was asymmetric to the left and when they were reading English it was asymmetric to the right. The results point out the importance of attentional factors in reading.     

Tardive dyskinesia and perceptual dysfunction

There is equivocal evidence for a relationship between neuroleptic-induced tardive dyskinesia and central nervous system (CNS) dysfunction. Using the Bender-Gestalt test as the dependent measure, we hypothesized that a group of chronic schizophrenic patients with tardive dyskinesia would show more perceptual dysfunction than those without. Our results supported this hypothesis. CNS dysfunction is discussed in terms of a possible predisposition to tardive dyskinesia.     

Considering sex differences in anxiety and its disorders across the life span: A construct-validation approach

One neglected avenue to understanding anxiety disorders is through studying patterns of sex differences, which may suggest the need for modification in definitions of anxiety and its disorders, their operationalization and measurement, and the theories associated with these constructs. This article begins with a comprehensive review of sex diffrences across the life span that supports the widely held view that most anxiety disorders are more common among females than males. Subsequently, we offer an analysis of the possible sources of sex differences from a construct-validity perspective, with emphasis on understanding whether sex differences have their basis in methodological problems, measurement or definitional problems, or problems in extant theories of anxiety themselves.     

Sentential structure and the perceptual span in normal reading development

An eye-voice span paradigm was adopted to determine whether children use different aspects of sentence structure to facilitate decoding early in the course of reading development. Eightyfour Grade 1 and Grade 2 children, representing four levels of early reading competence, and 15 skilled adult subjects read from four textual conditions; materials varied in the extent to which the texts were semantically and/or syntactically constrained. The more precocious the young reader, the longer his reported span. The better readers' and the adults' advantage was greater the more linguistically constrained the reading material. These data support a continuous model fo reading development and are compatible with an interactive definition of early reading behavior.     

Eye movements and the perceptual span in silent and oral reading

Previous research has examined parafoveal processing during silent reading, but little is known about the role of these processes in oral reading. Given that masking parafoveal information slows down silent reading, we asked whether a similar effect also occurs in oral reading. To investigate the role of parafoveal processing in silent and oral reading, we manipulated the parafoveal information available to readers by changing the size of a gaze-contingent moving window. Participants read silently and orally in a one-word window and a three-word window condition as we monitored their eye movements. The lack of parafoveal information slowed reading speed in both oral and silent reading. However, the effects of parafoveal information were larger in silent reading than in oral reading, because of different effects of preview information on both when the eyes move and how often. Parafoveal information benefitted silent reading for faster readers more than for slower readers.     

Adult age differences in the perceptual span during reading

Following up on research suggesting an age-related reduction in the rightward extent of the perceptual span during reading (Rayner, Castelhano, & Yang, 2009), we compared old and young adults in an N + 2-boundary paradigm in which a nonword preview of word N + 2 or word N + 2 itself is replaced by the target word once the eyes cross an invisible boundary located after word N. The intermediate word N + 1 was always three letters long. Gaze durations on word N + 2 were significantly shorter for identical than nonword N + 2 preview both for young and for old adults, with no significant difference in this preview benefit. Young adults, however, did modulate their gaze duration on word N more strongly than old adults in response to the difficulty of the parafoveal word N + 1. Taken together, the results suggest a dissociation of preview benefit and parafoveal-on-foveal effect. Results are discussed in terms of age-related decline in resilience towards distributed processing while simultaneously preserving the ability to integrate parafoveal information into foveal processing. As such, the present results relate to proposals of regulatory compensation strategies older adults use to secure an overall reading speed very similar to that of young adults.     

Eye movements and the perceptual span in beginning and skilled readers

Four experiments are reported which examined the size of the perceptual span in second-, fourth-, and sixth-grade children, as well as adult skilled readers. The results indicated that the perceptual span in beginning readers is slightly smaller than the perceptual span of skilled readers. Using a moving window technique, it was found that the perceptual span of beginning readers extends about 11 character spaces to the right of fixation; for skilled readers, the span extends 14-15 spaces to the right of fixation. Beginning readers apparently devote more of their processing to the foveally fixated word than more proficient readers, but their perceptual span appears to be asymmetric to the right of fixation as is the case for skilled readers. The results of the experiments also indicated that the size of the perceptual span is variable and can be influenced by the difficulty of the text. It is concluded that the size of the perceptual span does not cause beginning readers' slow reading rates.     

Vertical perceptual span and the processing of visual signals in reading

A previous study by Pollatsek et al. ( 1993 ) claims that the perceptual span in reading is restricted to the fixated line, i.e. readers typically focus their visual attention on the line of text being read. The present study investigated whether readers make use of content structure signals (paragraph indentations and topic headings) present several lines away from the currently fixated line. We reasoned that as these signals are low-resolution visual objects (as opposed to letter and word identity), readers may attend to them even if they are located some distance away from the fixated line. Participants read a hierarchically organized multi-topic expository text containing structure signals in either a normal condition or a window condition, where the text disappeared above and below a vertical 3° gaze-contingent region. After reading, participants were asked to produce a written recall of the text. The results showed that the overall reading rate was not affected by the window. Nevertheless, the headings were reread more in the normal condition than in the window one. In addition, more topics were recalled in the normal than in the window condition. We interpret the results as indicating that the readers visually attend to useful text layout features while considering bigger units than single text lines. The perception of topic headings located away from the fixated line may favour long-range regressions towards them, which in turn may favour text comprehension. This claim is consistent with previous studies that showed that look-back fixations to headings are performed with an integrative intent.     

小学二年级学生汉语阅读知觉广度的眼动研究

小学生阅读知觉广度是阅读发展心理学中的一个基本问题。本研究以Eyelink 1000 plus眼动仪为工具,采用2（年龄）×5（窗口）的两因素混合实验设计,考察小学二年级学生汉语阅读的知觉广度。结果显示,二年级学生的知觉广度为右侧1-2个汉字。二年级小学生快慢读者在眼动指标上存在差异,但未发现在知觉广度上存在差异。阅读能力测验与眼动指标存在显著的相关,此外小学二年级学生的阅读速度可以预测学业成绩。     

Skilled deaf readers have an enhanced perceptual span in reading

Recent evidence suggests that, compared with hearing people, deaf people have enhanced visual attention to simple stimuli viewed in the parafovea and periphery. Although a large part of reading involves processing the fixated words in foveal vision, readers also utilize information in parafoveal vision to preprocess upcoming words and decide where to look next. In the study reported here, we investigated whether auditory deprivation affects low-level visual processing during reading by comparing the perceptual span of deaf signers who were skilled and less-skilled readers with the perceptual span of skilled hearing readers. Compared with hearing readers, the two groups of deaf readers had a larger perceptual span than would be expected given their reading ability. These results provide the first evidence that deaf readers' enhanced attentional allocation to the parafovea is used during complex cognitive tasks, such as reading.     

Eye movements,the perceptual span,and reading speed

The perceptual span or region of effective vision during eye fixations in reading was examined as a function of reading speed (fast readers were compared with slow readers), font characteristics (fixed width vs. proportional width), and intraword spacing (normal or reduced). The main findings were that fast readers (reading at about 330 wpm) had a larger perceptual span than did slow readers (reading about 200 wpm) and that the span was not affected by whether or not the text was fixed width or proportional width. In addition, there were interesting font and intraword spacing effects that have important implications for the optimal use of space in a line of text.     

小学五年级语文学优生与学困生阅读知觉广度的眼动研究

本研究以眼动仪为工具,采用移动窗口范式来考察小学五年级语文学优生和学困生的阅读知觉广度。实验结果发现,小学五年级语文学优生的阅读知觉广度范围为注视字左侧一个汉字到注视字右侧三个汉字,小学五年级语文学困生的阅读知觉广度范围为注视字左侧一个汉字到注视字右侧两个汉字。小学五年级语文学优生的阅读知觉广度比学困生更大。