Lateral Onset Asynchrony in Left-Handers

1976 ◽  
Vol 43 (1) ◽  
pp. 255-259 ◽  
Author(s):  
Takeshi Hatta
Keyword(s):  
Visual Field ◽  
Standard Stimulus ◽  
The Other ◽  
Right Visual Field ◽  
Left Handed ◽  
The Right ◽  
Onset Asynchrony

Study of matching judgment was designed to demonstrate an effect of lateral onset asynchrony in left-handed subjects, 7 males and 8 females. Japanese Hirakana letters or random forms were presented to one visual field first and to the other visual field second. 15 left-handers were requested to judge whether the successively presented stimuli were “same” or “different.” The results showed that for both types of stimuli there are no differences in accuracy of matching judgment whether the standard stimulus was presented to the right visual field first or to the left. These results indicate that the left-handed subjects may have a tendency toward hemispheric equi-potentiality for recognition of both verbal and non-verbal materials.

Visual Masking, Handedness, and Laterality

1974 ◽  
Vol 38 (3) ◽  
pp. 803-811 ◽  
Author(s):  
S. M. Luria
Keyword(s):  
Visual Field ◽  
Left Visual Field ◽  
Visual Masking ◽  
Right Visual Field ◽  
Black Disk ◽  
Left Handed ◽  
Masking Stimulus ◽  
The Right

Monocular thresholds for a black disk and for single letters, presented either alone or followed by a masking stimulus, were obtained for both eyes of 16 left-handed Ss and 16 right-handed Ss. Thresholds for the disk tended to be lower when it was presented to the right visual field, particularly for the left eye and for right-handers. Thresholds for the letters tended to be lower when presented to the right visual field of right-handers and to the left visual field of left-handers. The masking stimulus enhanced these differences for the disk but not for the letters.

Individual Variation in Directional Bias in Visual Perception

Perception ◽  
1983 ◽  
Vol 12 (1) ◽  
pp. 71-84 ◽  
Author(s):  
Marian Annett
Keyword(s):  
Visual Field ◽  
Visual Perception ◽  
Visual Fields ◽  
Total Sample ◽  
Right Visual Field ◽  
Reading Habits ◽  
Directional Bias ◽  
The Right ◽  
Lateral Bias ◽  
Onset Asynchrony

Directional biases in visual perception were examined for individual differences in sixty-five subjects on two tasks. One task required judgments of the onset asynchrony of pairs of dots presented at random, either one dot in each visual field, or both in the left visual field (LVF), or the right visual field (RVF). The second task required the recall of four letter strings presented randomly in either visual field. Dot-asynchrony judgments were influenced by two main biases: first, an outward from the centre bias in both visual fields, and second, a lateral bias which was significantly from left to right (L—R) in the total sample. A substantial minority of subjects were biased to judge the dots as occurring in right to left (R—L) order. Accuracy of letter report decreased fairly consistently from L—R in the RVF but varied in the LVF. Some subjects showed a L—R report gradient, some a R—L gradient, and some a U-shaped recall pattern. Significant correlations between measures of L—R and R—L biases on the two tasks show that the biases have some stable foundation. The findings suggest that there are directional biases affecting visual perception which are due neither to learned reading habits, nor to cerebral specialization of function.

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.

Parallel but Temporally Displaced Visual Half-Field Metacontrast Functions

1974 ◽  
Vol 26 (2) ◽  
pp. 258-265 ◽  
Author(s):  
Walter F. McKeever ◽  
Max Suberi
Keyword(s):  
Visual Field ◽  
Stimulus Onset Asynchrony ◽  
Left Visual Field ◽  
Right Hemisphere ◽  
Stimulus Onset ◽  
Right Visual Field ◽  
Field Function ◽  
Processing Delay ◽  
The Right ◽  
Onset Asynchrony

Using a classic letter-ring metacontrast paradigm, left and right visual field meta-contrast functions were separately determined. The parallel U-shaped recognition functions for both half-fields were found to interact differentially with stimulus onset asynchrony, the left visual field function being displaced by 13 ms toward longer test stimulus-masking stimulus separations. This result was consistent with the hypothesis of longer processing time requirements for verbal stimuli delivered to the right than to the left hemisphere. This indicates that the neural locus (loci) responsible for left visual field verbal processing delay is (are) capable of mediating metacontrast phenomena. It was tentatively concluded that a relative processing delay within the right hemisphere underlies the differing visual half-field metacontrast interaction with stimulus onset asynchrony.

scholarly journals The influence of word valence on the right visual field advantage in the VHF paradigm: Time to adjust the expectations

2020 ◽  
Author(s):  
Pieter De Clercq ◽  
Marc Brysbaert
Keyword(s):  
Visual Field ◽  
Significant Interaction ◽  
Left Visual Field ◽  
Word Reading ◽  
The Other ◽  
Right Visual Field ◽  
Decision Task ◽  
Stimulus Characteristic ◽  
Positive Feelings ◽  
The Right

Previous studies found that valence (positive vs negative vs neutral) and visual half-field (left versus right) have an influence on word reading: Words are processed more efficiently when they evoke positive feelings and when they appear in the right visual field. In the present study we tried to address previous (contradictory) reports of an interaction between valence and visual half-field. A group of 39 right-handed undergraduates completed a lexical decision task in their native language (Dutch). They responded to 300 trials with real words (50 words per valence category - positive, negative, neutral – presented once in the left visual half-field and once in the right half-field) and 300 trials with non-words. Overall, participants responded more efficiently to positive words and there was a strong right visual field advantage. We did not find a significant interaction, however. Further analysis indicated that to find a replicable interaction between a stimulus characteristic and visual half-field, one requires much high numbers of participants and stimuli than done so far (and more than most researchers would be willing to invest). Experimental power is particularly low when the interaction is not fully crossed (a right visual field advantage for one type of stimulus and an equally large left visual field advantage for the other type of stimulus). If such investment cannot be made, the outcome is likely to be ambiguous at best and deceiving at worst if only significant findings are published.

Hemispheric Asymmetry as a Function of Handedness: Perception of Facial Affect Stimuli

1996 ◽  
Vol 82 (1) ◽  
pp. 264-266 ◽  
Author(s):  
D. Erik Everhart ◽  
David W. Harrison ◽  
W. David Crews
Keyword(s):  
Reaction Time ◽  
Visual Field ◽  
Hemispheric Asymmetry ◽  
Visual Fields ◽  
Forced Choice ◽  
Right Visual Field ◽  
Affective Stimuli ◽  
Left Handed ◽  
Left And Right ◽  
The Right

Hemispheric asymmetry in 14 left- and 14 right-handed persons shown tachistoscopically presented emotional stimuli to left and right visual fields was examined using a forced-choice, reaction-time paradigm in which subjects were asked to identify positive and negative faces. Neutral faces were included within the two-alternative forced-choice paradigm. Reaction time and response-bias measures were recorded. Analysis indicated differential lateralization for left-handed and right-handed subjects with respect to neutral affective stimuli. While right-handed subjects' perceptions of neutral stimuli remained consistent across visual fields, left-handed ones identified neutral stimuli as more positive (happy) when presented to the left visual field and negative (angry) when presented to the right visual field. Implications for differential lateralization patterns among left- and right-handed adults are discussed.

Differential Visual Field-Interhemispheric Transfer: Can it Explain Sex and Handedness Differences in Lateralization?

1987 ◽  
Vol 65 (2) ◽  
pp. 423-429 ◽  
Author(s):  
Richard H. Haude ◽  
Mary Morrow-Tlucak ◽  
Diane M. Fox ◽  
Kevin B. Pickard
Keyword(s):  
Visual Field ◽  
Left Hemisphere ◽  
Left Visual Field ◽  
Spatial Information ◽  
Right Hemisphere ◽  
Right Visual Field ◽  
Localization Task ◽  
Left Handed ◽  
Functional Lateralization ◽  
The Right

104 men and women were tested for visual field-hemispheric transfer of spatial information on a dot-localization task. Right-handed subjects showed significant improvement when stimuli were presented to the left visual field of the right hemisphere (LVF-RH) after practice on the same task presented to the right visual field of the left hemisphere (RVF-LH) first. No improvement was found when the task was presented in the reverse order (LVF-RH first followed by RVF-LH). It was concluded that, for right-handers, transfer of spatial information to the right hemisphere is facilitated while transfer to the left hemisphere is inhibited. Left-handed subjects demonstrated no significant improvement in either condition, suggesting inhibition or lack of transfer of spatial information in either direction. No sex differences were found in either right-handed or left-handed subjects. The findings suggest that there may be different mechanisms underlying the similarities in functional lateralization of women and left-handers.

Visual asymmetries during face encoding Increased dwell time and fixations in the upper and left hemifields

2018 ◽  
Author(s):  
Fatima Maria Felisberti
Keyword(s):  
Face Recognition ◽  
Eye Movements ◽  
Visual Field ◽  
Face Processing ◽  
Dwell Time ◽  
The Other ◽  
Environmental Cues ◽  
Reading Habits ◽  
The Right

Visual field asymmetries (VFA) in the encoding of groups rather than individual faces has been rarely investigated. Here, eye movements (dwell time (DT) and fixations (Fix)) were recorded during the encoding of three groups of four faces tagged with cheating, cooperative, or neutral behaviours. Faces in each of the three groups were placed in the upper left (UL), upper right (UR), lower left (LL), or lower right (LR) quadrants. Face recognition was equally high in the three groups. In contrast, the proportion of DT and Fix were higher for faces in the left than the right hemifield and in the upper rather than the lower hemifield. The overall time spent looking at the UL was higher than in the other quadrants. The findings are relevant to the understanding of VFA in face processing, especially groups of faces, and might be linked to environmental cues and/or reading habits.

scholarly journals Lateralization of attention in adults with ADHD: Evidence of pseudoneglect

2020 ◽  
Vol 63 (1) ◽  
Author(s):  
Bartosz Helfer ◽  
Stefanos Maltezos ◽  
Elizabeth Liddle ◽  
Jonna Kuntsi ◽  
Philip Asherson
Keyword(s):  
Reaction Time ◽  
Visual Field ◽  
Reaction Times ◽  
Study Participant ◽  
Reaction Time Task ◽  
Right Visual Field ◽  
Time Variability ◽  
Incentive Condition ◽  
Reaction Time Variability ◽  
The Right

Abstract Background. We investigated whether adults with attention-deficit/hyperactivity disorder (ADHD) show pseudoneglect—preferential allocation of attention to the left visual field (LVF) and a resulting slowing of mean reaction times (MRTs) in the right visual field (RVF), characteristic of neurotypical (NT) individuals —and whether lateralization of attention is modulated by presentation speed and incentives. Method. Fast Task, a four-choice reaction-time task where stimuli were presented in LVF or RVF, was used to investigate differences in MRT and reaction time variability (RTV) in adults with ADHD (n = 43) and NT adults (n = 46) between a slow/no-incentive and fast/incentive condition. In the lateralization analyses, pseudoneglect was assessed based on MRT, which was calculated separately for the LVF and RVF for each condition and each study participant. Results. Adults with ADHD had overall slower MRT and increased RTV relative to NT. MRT and RTV improved under the fast/incentive condition. Both groups showed RVF-slowing with no between-group or between-conditions differences in RVF-slowing. Conclusion. Adults with ADHD exhibited pseudoneglect, a NT pattern of lateralization of attention, which was not attenuated by presentation speed and incentives.

On the Relation between Visual Spatial Attention and Visual Field Asymmetries

1992 ◽  
Vol 44 (3) ◽  
pp. 529-555 ◽  
Author(s):  
T. A Mondor ◽  
M.P. Bryden
Keyword(s):  
Visual Field ◽  
Visual Attention ◽  
Visual Fields ◽  
Stimulus Onset ◽  
Right Visual Field ◽  
Structural Factors ◽  
Letter Identification ◽  
Functional Capabilities ◽  
Visual Spatial ◽  
The Right

In the typical visual laterality experiment, words and letters are more rapidly and accurately identified in the right visual field than in the left. However, while such studies usually control fixation, the deployment of visual attention is rarely restricted. The present studies investigated the influence of visual attention on the visual field asymmetries normally observed in single-letter identification and lexical decision tasks. Attention was controlled using a peripheral cue that provided advance knowledge of the location of the forthcoming stimulus. The time period between the onset of the cue and the onset of the stimulus (Stimulus Onset Asynchrony—SOA) was varied, such that the time available for attention to focus upon the location was controlled. At short SO As a right visual field advantage for identifying single letters and for making lexical decisions was apparent. However, at longer SOAs letters and words presented in the two visual fields were identified equally well. It is concluded that visual field advantages arise from an interaction of attentional and structural factors and that the attentional component in visual field asymmetries must be controlled in order to approximate more closely a true assessment of the relative functional capabilities of the right and left cerebral hemispheres.

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