Components of the Laterality Effect in Letter Recognition: Asymmetries in Iconic Storage

1976 ◽  
Vol 28 (1) ◽  
pp. 105-114 ◽  
Author(s):  
Gillian Cohen
Keyword(s):  
Visual Field ◽  
Left Visual Field ◽  
Letter Recognition ◽  
Partial Report ◽  
Right Visual Field ◽  
Backward Masking ◽  
Selective Sampling ◽  
Full Report ◽  
Laterality Effect ◽  
The Right

A partial report procedure and a backward masking paradigm were employed to explore lateral asymmetries in components of letter recognition. Stimulus displays were displaced off-centre into the left visual field (LVF) or the right visual field (RVF). Visual field differences in the effect of a delayed backward mask indicated an RVF superiority in the rate of read-out or encoding. Comparison of masked and unmasked full report also yielded estimates of iconic persistence. The persistence of these peripheral displays was surprisingly brief, although it was significantly longer in the LVF (57 ms) than in the RVF (34 ms). Precueing by colour and by location produced a larger partial report advantage in the RVF, reflecting a superiority in selective sampling. With postcueing no partial report effect was obtained at any delay, and this failure was attributed to the briefness of the iconic persistence.

Asynchrony of Lateral Onset as a Factor in Difference in Visual Field

1976 ◽  
Vol 42 (1) ◽  
pp. 163-166 ◽  
Author(s):  
Takeshi Hatta
Keyword(s):  
Visual Field ◽  
Left Hemisphere ◽  
Left Visual Field ◽  
Right Visual Field ◽  
Perceptual Process ◽  
Experimental Conditions ◽  
Stimulus Interval ◽  
Laterality Effect ◽  
The Right

An experiment in matching judgments was designed to examine a role of perceptual process in apparent asymmetry. Recognition of Hirakana letters (Japanese letters) was required. The experimental condition in which stimuli were presented to the left visual field first and to the right visual field second produced more errors for all stimulus intervals (0 to 60 msec.) than experimental conditions where stimuli were presented to the right visual field first and to the left one second. Especially, superiority of the latter condition was marked with the longest stimulus interval employed. These results indicate superiority of the left hemisphere function for recognizing Hirakana letters and suggest that not only memory but also perceptual process contributes to this laterality effect.

Lateral Asymmetry in Visual Detection under Hypnosis

1987 ◽  
Vol 65 (3) ◽  
pp. 899-906 ◽  
Author(s):  
Edward J. Hass ◽  
Christopher W. Holden
Keyword(s):  
Visual Field ◽  
Response Time ◽  
Left Visual Field ◽  
Priming Effect ◽  
Visual Detection ◽  
Dependent Measure ◽  
Right Visual Field ◽  
Lateral Asymmetry ◽  
Control Subjects ◽  
The Right

It has been suggested that the hypnotic state results in a greater relative activation or priming of the right cerebral hemisphere than of the left hemisphere. The experiment reported here employed hypnosis to produce such a priming effect in a visual-detection task. Subjects were required to detect the presence or absence of a gap in outline squares presented either to the left visual field or right visual field, with response time as the primary dependent measure. Those subjects who were hypnotized produced a 50-msec. response time difference favoring squares presented to the left visual field whereas control subjects and simulator-control subjects showed no lateral asymmetries. The result is classified as a material-nonspecific priming effect and discussed with regard to the nature of processing resources.

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.

Critique of Heron's Directional-Reading Conflict Theory of Scanning

1969 ◽  
Vol 29 (1) ◽  
pp. 271-276 ◽  
Author(s):  
Robert Fudin
Keyword(s):  
Visual Field ◽  
Eye Movement ◽  
Left Visual Field ◽  
Critical Evaluation ◽  
Slight Modification ◽  
Conflict Theory ◽  
Right Visual Field ◽  
The Right ◽  
The Way

Heron (1957) proposed a theory of scanning of tachistoscopically presented alphabetical stimuli. It provided a unifying framework to interpret the disparate results obtained when a target is exposed such that half of it is in the left visual field and half in the right visual field, and when arrays are presented laterally, i.e., either in the right or left field. The theory basically holds that eye-movement tendencies established through reading are also operative in covert scanning because tachistoscopically exposed material is encoded in a manner similar to the way it is read. This paper accepts this position but offers a critical evaluation of Heron's ideas as to the manner in which these tendencies function. This discussion and a reexamination of the role of these tendencies in reading lead to the conclusion that they operate sequentially, not simultaneously, as Heron contended. A slight modification in Heron's theory is offered in light of this conclusion.

Effect of Lateral Eye Fixation on Cognitive Processes

1981 ◽  
Vol 52 (2) ◽  
pp. 487-490 ◽  
Author(s):  
Ronald A. La Torre ◽  
Anne-Marie La Torre
Keyword(s):  
Visual Field ◽  
Left Visual Field ◽  
Spatial Task ◽  
Right Visual Field ◽  
Control Group ◽  
Intelligence Scale ◽  
Eye Fixation ◽  
Lateral Eye ◽  
The Right ◽  
Spatial Problems

Fourth grade children responded to verbal and spatial problems drawn from the Wechsler Intelligence Scale for Children. 24 responded to verbal problems while attending to the right visual field and to spatial problems while attending to the left visual field; 24 fixed attention to the left visual field during verbal problems and to the right visual field during spatial problems. A final 24 children fixed their attention centrally while responding to both sets of problems. There were no significant differences among the groups for verbal performance. Spatial problems were dealt with least effectively during right visual-field eye-fixation. Perhaps right visual-field fixation during a spatial task leads to interference with capacity and from functional distance. Left visual-field fixation might be facilitating as a result of functional closeness but this facilitation is offset by interference with capacity making the over-all result not significantly different from that for the control group. Verbal centers may be insulated against effects of interference.

Effect of Learning on Hemispheric Dominance and Free Recall in a Single Subject

1972 ◽  
Vol 31 (1) ◽  
pp. 227-230 ◽  
Author(s):  
Lester C. Shine ◽  
Joseph Wiant ◽  
Frank Da Polito
Keyword(s):  
Free Recall ◽  
Visual Field ◽  
Analysis Of Variance ◽  
Field Condition ◽  
Left Visual Field ◽  
Visual Fields ◽  
Hemispheric Dominance ◽  
Right Visual Field ◽  
Single Subject ◽  
The Right

This experiment was designed to investigate the effect of learning on the free recall of letters presented tachistoscopically either to the left visual field, the right visual field, or identically and simultaneously to both visual fields. A modified Shine-Bower analysis of variance was used to analyze S's performance. The results indicate that initially, in accord with previous research, the right visual field is superior to the left visual field in performance, but that this superiority tends to reduce across trials and practically disappears in the later trials. Also, the right visual field condition is not appreciably better in performance than the condition with both visual fields.

Electroencephalographic Activity in a Flanker Interference Task Using Japanese Orthography

2002 ◽  
Vol 14 (7) ◽  
pp. 971-979 ◽  
Author(s):  
Shuhei Yamaguchi ◽  
Genya Toyoda ◽  
Jiang Xu ◽  
Shotai Kobayashi ◽  
Avishai Henik
Keyword(s):  
Visual Field ◽  
Left Visual Field ◽  
Right Hemisphere ◽  
Hemispheric Specialization ◽  
Late Phase ◽  
Right Visual Field ◽  
Interference Effects ◽  
Interference Task ◽  
Dorsolateral Prefrontal ◽  
The Right

The neural activities for color word interference effects were investigated using event-related brain potentials (ERPs) recorded in a flanker-type interference task. Kanji words (Japanese morphograms) and kana words (Japanese phono-grams) were used as the flanker stimuli to obtain insights about hemispheric specialization for processing two types of Japanese orthographies. Interference effects in reaction time were larger when kanji words were presented in the left visual field and when kana words were in the right visual field. ERPs were modulated by the incongruent flankers, which generated a negative ERP component with the different onset and offset depending on flanker attributes. Consistent with the behavioral data, the interference-related negativity was observed for kanji words presented in the left visual field and for kana words in the right visual field. The negativity distributed maximally over the fronto-central site. The early part of the negativity distributed strongly over the frontal midline area, whereas it extended bilaterally over the frontal area in the late phase. The present results support the view of preferential processing of kanji in the right hemisphere and that of kana in the left hemisphere. The temporal profile of scalp topographies for the interference-related neural activity suggests that the medial and dorsolateral prefrontal regions may be involved in maintaining attentional set and conflict resolution.

Rebalancing Spatial Attention: Endogenous Orienting May Partially Overcome the Left Visual Field Bias in Rapid Serial Visual Presentation

2017 ◽  
Vol 29 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Kamila Śmigasiewicz ◽  
Gabriel Sami Hasan ◽  
Rolf Verleger
Keyword(s):  
Visual Field ◽  
Spatial Attention ◽  
Left Visual Field ◽  
Visual Presentation ◽  
Right Visual Field ◽  
Alpha Power ◽  
Unequal Distribution ◽  
Endogenous Orienting ◽  
T1 And T2 ◽  
The Right

In dynamically changing environments, spatial attention is not equally distributed across the visual field. For instance, when two streams of stimuli are presented left and right, the second target (T2) is better identified in the left visual field (LVF) than in the right visual field (RVF). Recently, it has been shown that this bias is related to weaker stimulus-driven orienting of attention toward the RVF: The RVF disadvantage was reduced with salient task-irrelevant valid cues and increased with invalid cues. Here we studied if also endogenous orienting of attention may compensate for this unequal distribution of stimulus-driven attention. Explicit information was provided about the location of T1 and T2. Effectiveness of the cue manipulation was confirmed by EEG measures: decreasing alpha power before stream onset with informative cues, earlier latencies of potentials evoked by T1-preceding distractors at the right than at the left hemisphere when T1 was cued left, and decreasing T1- and T2-evoked N2pc amplitudes with informative cues. Importantly, informative cues reduced (though did not completely abolish) the LVF advantage, indicated by improved identification of right T2, and reflected by earlier N2pc latency evoked by right T2 and larger decrease in alpha power after cues indicating right T2. Overall, these results suggest that endogenously driven attention facilitates stimulus-driven orienting of attention toward the RVF, thereby partially overcoming the basic LVF bias in spatial attention.

Visual-Field Asymmetries in Letter Recognition: Evidence for Asymmetry in Early Visual Registration

1979 ◽  
Vol 49 (1) ◽  
pp. 183-191
Author(s):  
Colin Pitblado ◽  
Michael Petrides ◽  
Gary Riccio
Keyword(s):  
Visual Field ◽  
Recognition Accuracy ◽  
Visual Fields ◽  
Normal Subjects ◽  
Letter Recognition ◽  
Right Visual Field ◽  
Cerebral Asymmetry ◽  
Exposure Field ◽  
The Right

Two experiments on visual-field differences in tachistoscopic letter recognition are described. In the first, a bright pre-exposure field with a black fixation point was used, and the conventionally expected dominance of the right visual field was found. However, a large number of “blank” trials were observed, in which subjects completely failed to detect the presence of the flashed target. These “blanks” were themselves significantly asymmetric between visual fields, suggesting that asymmetry in early stimulus registration may play an unsuspected role in typical measures of cerebral asymmetry in recognition accuracy. This was confirmed in a second experiment in which use of dark pre-exposure fields eliminated “blanks” and led to higher over-all accuracy, with no visual-field differences. Implications for interpretation of laterality data with normal subjects are discussed.

Visual Masking with Presentations in Same and opposite Visual Fields: Evidence for Contralateral Masking

1982 ◽  
Vol 55 (1) ◽  
pp. 131-140 ◽  
Author(s):  
Dennis P. Saccuzzo ◽  
Brad E. Michael ◽  
Robert Rowe
Keyword(s):  
Visual Field ◽  
Target Stimulus ◽  
Visual Masking ◽  
Visual Fields ◽  
Right Visual Field ◽  
Future Research ◽  
Backward Masking ◽  
Masking Stimulus ◽  
The Right ◽  
Contralateral Masking

Three experiments were conducted in a preliminary attempt to study the effects of presentations of an informational target stimulus to the right or left visual fields when the target was either preceded or followed by a non-informational masking stimulus and when the mask was presented to the same or opposite visual field of the target. Results indicated that masking was more effective in the same than in the opposite visual field but that masking of the opposite visual field was feasible for both forward and backward masking. Laterality effects were also found for forward and backward masking, with a modest advantage of the right visual field (left hemisphere) in both cases. Limitations of the data and directions for future research were discussed.

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