Some Effects of Advanced Aging on the Visual-Language Processing Capacity of the Left and Right Hemispheres

1990 ◽  
Vol 33 (1) ◽  
pp. 134-140 ◽  
Author(s):  
Michael P. Rastatter ◽  
Richard A. McGuire
Keyword(s):  
Visual Field ◽  
Language Processing ◽  
False Positive ◽  
False Negative ◽  
Visual Fields ◽  
Reaction Times ◽  
Elderly Subjects ◽  
Time Data ◽  
Error Type ◽  
Left And Right

The present study investigated the effects of advanced aging on hemispheric organization for visual-linguistic processing. Lexical decision vocal-reaction times of geriatric subjects were measured for unilaterally presented concrete and abstract nouns in an attempt to obtain an index of differential left and right hemispheric processing ability. Results of an ANOVA procedure showed that reaction times were significantly faster when subjects were presented the stimulus items in their right visual fields, regardless of whether the item was a concrete or abstract word. An ANOVA procedure applied to the arcsine of the percentages of occurrence of false-positive and false-negative error types showed a significant interaction between the error type and visual field variables. Post hoc tests showed left visual field, false-positive errors occurred significantly more often than the remaining visual field, error type configurations. Finally, for the reaction time data, a significant correlation existed between the two visual fields for the concrete and abstract items. Collectively, such findings were consistent with a callosal relay model of neurolinguistic organization, suggesting that the right hemisphere’s ability to perform lexical decisions was diminished in the present group of elderly subjects.

Hemispheric Specialization for Processing Chinese Characters: Some Evidence from Lexical Decision Vocal Reaction Times

1989 ◽  
Vol 69 (3_suppl) ◽  
pp. 1083-1089 ◽  
Author(s):  
Michael P. Rastatter ◽  
Gail Scukanec ◽  
Jeff Grilliot
Keyword(s):  
Visual Field ◽  
Lexical Decision ◽  
Hemispheric Specialization ◽  
Visual Fields ◽  
Reaction Times ◽  
Decision Processes ◽  
Right Visual Field ◽  
Chinese Characters ◽  
Error Type ◽  
Chinese Subjects

Lexical decision vocal reaction times (RT) were obtained for a group of Chinese subjects to unilateral tachistoscopically presented pictorial, single, and combination Chinese characters. The RT showed a significant right visual-field advantage, with significant correlations of performance between the visual fields for each type of character. Error analysis gave a significant interaction between visual fields and error type—significantly more false positive errors occurred following left visual-field inputs. These results suggest that the left hemisphere was responsible for processing each type of character, possibly reflecting superior postaccess lexical-decision processes.

Technology Study on the Perception of Stereopsis in Fovea Field

2014 ◽  
Vol 1022 ◽  
pp. 341-344
Author(s):  
Yan Wu ◽  
Qi Li ◽  
Xiang Bo Han ◽  
Hui Ling Shen
Keyword(s):  
Visual Field ◽  
Visual Fields ◽  
Reaction Times ◽  
Right Visual Field ◽  
Technology Study ◽  
Random Dot Stereograms ◽  
Left And Right

Random-dot stereograms were used as stimuli to investigate the perception of stereopsis in fovea field. The response of every subject was recorded in different positions in the fovea field: upper, lower, left, right field and with different eccentricities of 1.39º, 1.93º, 2.48º, 3.02º, 3.57º. The results showed that reaction times increased with increasing eccentricities wherever the disparity zone was presented relative to the fixation point. No significant differences were found between reaction times to the upper and lower visual fields. And there were no significant differences between left and right visual field. But there were marked superiorities for reaction times between upper and right field at all eccentricities.

Hemispheric Specialization for Processing Chinese Characters: Some Evidence from Lexical Decision Vocal Reaction Times

1989 ◽  
Vol 69 (3-2) ◽  
pp. 1083-1089 ◽  
Author(s):  
Michael P. Rastatter ◽  
Gail Scukanec ◽  
Jeff Grilliot
Keyword(s):  
Visual Field ◽  
Lexical Decision ◽  
Hemispheric Specialization ◽  
Visual Fields ◽  
Reaction Times ◽  
Decision Processes ◽  
Right Visual Field ◽  
Chinese Characters ◽  
Error Type ◽  
Chinese Subjects

Lexical decision vocal reaction times (RT) were obtained for a group of Chinese subjects to unilateral tachistoscopically presented pictorial, single, and combination Chinese characters. The RT showed a significant right visual-field advantage, with significant correlations of performance between the visual fields for each type of character. Error analysis gave a significant interaction between visual fields and error type—significantly more false positive errors occurred following left visual-field inputs. These results suggest that the left hemisphere was responsible for processing each type of character, possibly reflecting superior postaccess lexical-decision processes.

Vocal Reaction Times to Tachistoscopically Presented High- and Low-Frequency Verbs: Some Evidence for Selective Minor Hemisphere Linguistic Analysis

1988 ◽  
Vol 66 (3) ◽  
pp. 803-810 ◽  
Author(s):  
Michael P. Rastatter ◽  
Catherine Loren
Keyword(s):  
Visual Field ◽  
High Frequency ◽  
Right Hemisphere ◽  
Visual Fields ◽  
Reaction Times ◽  
Low Frequency ◽  
Normal Subjects ◽  
Right Visual Field ◽  
Intact Brain ◽  
The Right

The current study investigated the capacity of the right hemisphere to process verbs using a paradigm proven reliable for predicting differential, minor hemisphere lexical analysis in the normal, intact brain. Vocal reaction times of normal subjects were measured to unilaterally presented verbs of high and of low frequency. A significant interaction was noted between the stimulus items and visual fields. Post hoc tests showed that vocal reaction times to verbs of high frequency were significantly faster following right visual-field presentations (right hemisphere). No significant differences in vocal reaction time occurred between the two visual fields for the verbs of low frequency. Also, significant differences were observed between the two types of verbs following left visual-field presentation but not the right. These results were interpreted to suggest that right-hemispheric analysis was restricted to the verbs of high frequency in the presence of a dominant left hemisphere.

Hemispheric Processing Characteristics for Lexical Decisions in Adults with Reading Disorders

2001 ◽  
Vol 92 (1) ◽  
pp. 273-287 ◽  
Author(s):  
Marianna M. Walker ◽  
Hiller Spires ◽  
Michael P. Rastatter
Keyword(s):  
Visual Field ◽  
Stimulus Type ◽  
Visual Fields ◽  
Reaction Times ◽  
Error Rates ◽  
Reading Disorders ◽  
Lexical Decisions ◽  
Abstract Words ◽  
Post Hoc ◽  
Lexical Transfer

The present study measured unilateral tachistoscopic vocal reaction times and error responses of reading-disordered and normally reading adults to single words and nonwords in a series of lexical decision tasks at two linguistic levels (concrete and abstract words). Analysis of variance on reaction times indicated that main effects of stimulus type, visual field, and the interaction of these variables were not significant for the reading-disordered group, but visual field and an interaction of visual field and stimulus type were for the normally reading adults. Error rate showed a significant interaction of stimulus x visual field for the reading-disordered group but not for the normal reading group. Post hoc tests showed significant differences in error rates between visual fields for concrete lexicon but not for abstract or nonsense lexicon for the reading-disordered group. These findings suggest a deficit in interhemispheric lexical transfer occurs for reading-disordered samples and suggest use of a callosal relay model wherein the left hemisphere is allocated responsibility for performing central operations underlying lexical decisions by adults with reading disorders.

Reaction Times of Aging Subjects to Monaural Verbal Stimuli

1987 ◽  
Vol 30 (2) ◽  
pp. 261-267 ◽  
Author(s):  
Michael P. Rastatter ◽  
Cindy Lawson-Brill
Keyword(s):  
Left Hemisphere ◽  
Language Processing ◽  
Reaction Times ◽  
Elderly Subjects ◽  
Linguistic Processing ◽  
Verbal Stimuli ◽  
Language Analysis ◽  
Processing Ability ◽  
Advanced Stages ◽  
Young Subjects

The purpose of the current study was to investigate the effects of advanced aging on hemispheric organization for linguistic processing. Specifically, it was an attempt to identify whether the neurological substrate responsible for right-hemispheric language analysis diminishes in function. Measures of the influence on reaction time of the hand used to respond versus the hemisphere stimulated were obtained for a geriatric sample in an attempt to obtain an index of right-versus left-hemisphere auditory-verbal processing ability. Twenty-four right-handed geriatric subjects responded to monaurally presented verbal stimuli with their right and left hands at separate times. Reaction times were significantly faster when subjects heard the words in their right ears, regardless of the hand used to respond. Such findings were consistent with a strict model of neurolinguistic organization that suggests that the left hemisphere was responsible solely for language processing in the present group of elderly subjects. Compared to data previously gathered for young subjects, the current findings were interpreted to suggest that right-hemispheric language processing ability is inhibited in the more advanced stages of life.

Vocal Reaction Times of Stuttering Subjects to Tachistoscopically Presented Concrete and Abstract Words

1987 ◽  
Vol 30 (3) ◽  
pp. 306-310 ◽  
Author(s):  
Michael P. Rastatter ◽  
Carl Dell
Keyword(s):  
Language Processing ◽  
Right Hemisphere ◽  
Visual Fields ◽  
Reaction Times ◽  
Normal Subjects ◽  
Decision Task ◽  
Functional Localization ◽  
Past Data ◽  
Abstract Words ◽  
The Right

The present study was an attempt to investigate further the issues pertaining to cerebral organization for visual language processing in the stuttering population. Employing a lexical decision task, vocal reaction times were obtained for a group of 14 stutterers to unilateral, tachistoscopically presented concrete and abstract words. Results of an analysis of variance showed that a significant interaction occurred between visual fields and stimuli. Posthoc tests showed that the right hemisphere was superior for analyzing the concrete words while the left hemisphere was responsible for processing the abstract items. Compared to past data from normal subjects, these findings were interpreted as suggesting that some form of linguistic competition may exist between the two hemispheres, possibly reflecting a disturbance in functional localization in the stuttering population.

The Lateralizer: a tool for students to explore the divided brain

2012 ◽  
Vol 36 (3) ◽  
pp. 220-225 ◽  
Author(s):  
Benjamin A. Motz ◽  
Karin H. James ◽  
Thomas A. Busey
Keyword(s):  
Visual Field ◽  
Undergraduate Students ◽  
Visual Fields ◽  
Cerebral Hemispheres ◽  
Brain Anatomy ◽  
Skill Sets ◽  
Divided Visual Field ◽  
Field Technique ◽  
Left And Right ◽  
And Function

Despite a profusion of popular misinformation about the left brain and right brain, there are functional differences between the left and right cerebral hemispheres in humans. Evidence from split-brain patients, individuals with unilateral brain damage, and neuroimaging studies suggest that each hemisphere may be specialized for certain cognitive processes. One way to easily explore these hemispheric asymmetries is with the divided visual field technique, where visual stimuli are presented on either the left or right side of the visual field and task performance is compared between these two conditions; any behavioral differences between the left and right visual fields may be interpreted as evidence for functional asymmetries between the left and right cerebral hemispheres. We developed a simple software package that implements the divided visual field technique, called the Lateralizer, and introduced this experimental approach as a problem-based learning module in a lower-division research methods course. Second-year undergraduate students used the Lateralizer to experimentally challenge and explore theories of the differences between the left and right cerebral hemispheres. Measured learning outcomes after active exploration with the Lateralizer, including new knowledge of brain anatomy and connectivity, were on par with those observed in an upper-division lecture course. Moreover, the project added to the students' research skill sets and seemed to foster an appreciation of the link between brain anatomy and function.

Models of Response Time to Peripheral Stimuli

1974 ◽  
Vol 18 (5) ◽  
pp. 533-533
Author(s):  
D.S. Kochhar ◽  
T.M. Fraser
Keyword(s):  
Visual Field ◽  
Response Time ◽  
Visual Fields ◽  
Stimulus Location ◽  
Stimulus Size ◽  
Tracking Task ◽  
Right Visual Field ◽  
Simulated Driving ◽  
Left And Right ◽  
The Right

The variable contribution of peripherally presented stimuli in a A sensory motor task has been explored in terms of stimulus and environmental variables. A simulated driving task was chosen as being a representative compensatory tracking task. Empirical models have been developed using response surface methodology, statistical design and data collected on a simulator with a 240° wrap-around screen and projection systems very much like cinerama. In this research, seven factors were isolated for a study of their effects on detection latency to peripherally presented stimuli when the subject was ‘driving’. These factors were stimulus size (circular stimuli between 18′ and 60′), stimulus color (red, white and green), stimulus-background contrast (background luminance 1ft.L and stimulus luminance of 30, 60 and 90 ft.L), stimulus location along the horizontal (between ± 90°) and vertical meridians (between ± 26°), intensity of continuous white noise (between 52 and 100 dbA), and complexity of the continuous central tracking task measured in terms of the simulated driving speed. Three levels of each variable were selected in a 7 factor Box-Behnken design. Twenty undergraduates between the ages 19 and 26 participated in the experiment. It was found that, in this multivariable environment when all seven factors were simultaneously varied, the effects of noise, stimulus location in the visual field and stimulus size were the more important determinants of response latency. In addition, marked differences for the left and right visual fields were observed for the right-handed subject population. Four models have been developed: two for the left visual field, with and without the continuous central task (CCT), and two for the right visual field for the same conditions. The response was found to be of the form 1/Yr = f (xi); i= 1,2,… 7 for both the left and right visual fields in the presence of the CCT. In the absence of the CCT the model was of the form Yr = f (xr) for the left and 1/2 = f (xi) for the right visual field where Yr = response time in millisec. and Yr xi = variables in equations. Response curves have been presented to illustrate the variation of response time with each of the seven variables for regions where response time may be expected to be a minimum. The implications of these curves and the models on which they are based have been examined from the design point of view.

Left—Right Visual Field Asymmetry in Bistable Motion Perception

Perception ◽  
1988 ◽  
Vol 17 (6) ◽  
pp. 721-727 ◽  
Author(s):  
Clara Casco ◽  
Donatella Spinelli
Keyword(s):  
Visual Field ◽  
Visual Fields ◽  
Stimulus Presentation ◽  
The Other ◽  
Right Visual Field ◽  
The Third ◽  
Group Movement ◽  
Left Handed ◽  
Left And Right ◽  
Left Right Asymmetry

Twelve observers viewed two alternating frames, each consisting of three rectangular bars which were displaced laterally by one cycle in one frame with respect to the other. At long interframe intervals (IFIs) observers perceived a group of three elements moving as a whole (group movement), whereas with IFIs shorter than 40–60 ms the overlapping elements in each frame appeared stationary while the third element appeared to move from one end of the display to the other (end-to-end movement). The percentage of group movement responses in central viewing was compared to those obtained for stimulus presentation in the left and right visual fields (4 deg eccentricity), for opposite horizontal directions of motion. All ten right-handed subjects showed a left-field advantage in sensitivity to group movement. The two left-handed subjects showed a similar advantage in sensitivity with right-field presentation. The effects of monocular vision, hand used in the task, spatial frequency, and contrast on visual field asymmetry were all investigated in two right-handed subjects. None of these factors affected the left—right asymmetry.

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