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

1969 ◽  
Vol 29 (1) ◽  
pp. 271-276 ◽  
Author(s):  
Robert Fudin

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.

1976 ◽  
Vol 42 (1) ◽  
pp. 163-166 ◽  
Author(s):  
Takeshi Hatta

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.


1987 ◽  
Vol 65 (3) ◽  
pp. 899-906 ◽  
Author(s):  
Edward J. Hass ◽  
Christopher W. Holden

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.


1974 ◽  
Vol 38 (3) ◽  
pp. 803-811 ◽  
Author(s):  
S. M. Luria

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.


1981 ◽  
Vol 52 (2) ◽  
pp. 487-490 ◽  
Author(s):  
Ronald A. La Torre ◽  
Anne-Marie La Torre

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.


1972 ◽  
Vol 31 (1) ◽  
pp. 227-230 ◽  
Author(s):  
Lester C. Shine ◽  
Joseph Wiant ◽  
Frank Da Polito

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.


2002 ◽  
Vol 14 (7) ◽  
pp. 971-979 ◽  
Author(s):  
Shuhei Yamaguchi ◽  
Genya Toyoda ◽  
Jiang Xu ◽  
Shotai Kobayashi ◽  
Avishai Henik

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.


2017 ◽  
Vol 29 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Kamila Śmigasiewicz ◽  
Gabriel Sami Hasan ◽  
Rolf Verleger

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.


2015 ◽  
Vol 27 (2) ◽  
pp. 266-279 ◽  
Author(s):  
Kamila Śmigasiewicz ◽  
Dariusz Asanowicz ◽  
Nicole Westphal ◽  
Rolf Verleger

Everyday experience suggests that people are equally aware of stimuli in both hemifields. However, when two streams of stimuli are rapidly presented left and right, the second target (T2) is better identified in the left hemifield than in the right hemifield. This left visual field (LVF) advantage may result from differences between hemifields in attracting attention. Therefore, we introduced a visual cue shortly before T2 onset to draw attention to one stream. Thus, to identify T2, attention was correctly positioned with valid cues but had to be redirected to the other stream with invalid ones. If the LVF advantage is caused by differences between hemifields in attracting attention, invalid cues should increase, and valid cues should reduce the LVF advantage as compared with neutral cues. This prediction was confirmed. ERP analysis revealed that cues evoked an early posterior negativity, confirming that attention was attracted by the cue. This negativity was earlier with cues in the LVF, which suggests that responses to salient events are faster in the right hemisphere than in the left hemisphere. Valid cues speeded up, and invalid cues delayed T2-evoked N2pc; in addition, valid cues enlarged T2-evoked P3. After N2pc, right-side T2 evoked more sustained contralateral negativity than left T2, least long-lasting after valid cues. Difficulties in identifying invalidly cued right T2 were reflected in prematurely ending P3 waveforms. Overall, these data provide evidence that the LVF advantage is because of different abilities of the hemispheres in shifting attention to relevant events in their contralateral hemifield.


1974 ◽  
Vol 26 (2) ◽  
pp. 258-265 ◽  
Author(s):  
Walter F. McKeever ◽  
Max Suberi

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.


1972 ◽  
Vol 35 (3) ◽  
pp. 951-959 ◽  
Author(s):  
Robert Fudin ◽  
John T. Kenny

Six-letter nonsense arrays, constructed from a 12-letter population which was not made known to 20 Ss, were tachistoscopically shown successively in the right visual field (RVF) and left visual field (LVF) at three displacements from a central fixation point. Recognition scores were higher for stimuli in the RVF at each displacement. In each case RVF superiority was limited to letters in the first array-half (letters 1, 2, 3). These results agree with prior findings obtained with targets made up of six letters known to S (Fudin, 1969). Reportability of a tachistoscopically exposed letter, in part, is a function of the relationship between its retinal location and the delay before it is scanned. Location determines the amount of information a letter contains before it starts to fade-out (the more acute the area, the greater the information), delay determines the period of information dissipation prior to scanning. These ideas were used to explain the contrast between high error scores for middle-array letters in the bow-shaped error curves found in this experiment and the low values often reported for these letters when targets are shown across fixation, and the finding that the difference between error scores for letters in the first and second array-halves was greater for targets at each displacement in the right than the left visual field.


Sign in / Sign up

Export Citation Format

Share Document