Spatial attention in early vision

The present study addressed whether the allocation of attention to a particular region in space can prevent processing of distractor information from non-attended regions. A cue indicated the area in visual space where the target singleton would be presented. Observers were required to detect this target singleton and ignore a distractor singleton presented within a non-attended region. The results indicate that the allocation of attention to a region in space cannot prevent the processing of unwanted information from elsewhere in the visual field. It is concluded that the function of the allocation of attention is not to enhance the processing capacity within the attended region but rather to attenuate interference from distractors in unattended regions.     

Spatial attention is necessary for object-based attention: Evidence from temporal-order judgments

Attentional selection is a dynamic process that relies on multiple types of representations. That object representations contribute to attentional selection has been known for decades; however, most evidence for this contribution has been gleaned from studies that have relied on various forms of spatial cueing (some endogenous and some exogenous). It has thus remained unclear whether object-based attentional selection is a direct result of spatial cuing, or whether it still emerges without any spatial marker. Here we used a novel method—the temporal-order judgment (TOJ)—to examine whether object-based guidance emerges in the absence of spatial cuing. Participants were presented with two rectangles oriented either horizontally or vertically. Following a 150-ms preview time, two target stimuli were presented on the same or on different objects, and participants were asked to report which of the two stimuli had appeared first. The targets consisted of stimuli that formed a percept of a “hole” or a “hill.” First, we demonstrated that the “hill” target was indeed processed faster, as evidenced by a positive perceived simultaneity (PSS) measure. We then demonstrated that if two targets appeared with equal probabilities on the same and on different objects, the PSS values, although positive, were not modulated by the objects. In a subsequent set of experiments, we showed that objects can modulate attentional allocation—however, only when they are biased by a spatial (endogenous) cue. In other words, in the absence of a spatial cue or bias, object representations do not guide attentional selection. In addition to providing new constraints for theories of object-based attentional guidance, these experiments introduce a novel paradigm for measuring object-based attentional effects.     

Visual attention in reading: Eye movements reflect cognitive processes

Two hypotheses regarding the nature of fixation durations in reading were discussed. One position suggests that semantic processing lags behind the perceptual input of information. The other position suggests that semantic processing is more rapid and immediate. Eye movement data of skilled readers reading passages of text were analyzed. It was found that the main verb of the sentence received more visual attention than other key grammatical elements within a sentence. On the basis of the overall result pattern, it was argued that eye movements are affected by cognitive processes occurring at the time of the fixations.     

Disgust-specific modulation of early attention processes

Although threatening images are known to attract and keep our attention, little is known about the existence of emotion-specific attention effects. In this study (N = 46), characteristics of an anticipated, disgust-specific effect were investigated by means of a covert orienting paradigm incorporating pictures that were either disgust-evoking, fear-evoking, happiness-evoking or neutral. Attention adhesion to these pictures was measured by the time necessary to identify a peripheral target, presented 100, 200, 500, or 800 ms after picture onset. Main results showed that reaction times were delayed for targets following the disgust-evoking pictures by 100 and 200 ms, suggesting that only these pictures temporarily grabbed hold of participants' attention. These delays were similar for ignore- and attend-instructions, and they were not affected by the participants' anxiety levels or disgust sensitivity. The disgust-specific influence on early attention processes thus appeared very robust, occurring in the majority of participants and without contribution of voluntary- and strategic-attention processes. In contrast, a smaller and less reliable effect of all emotional (arousing) pictures was present in the form of delayed responding in the 100 ms cue-target interval. This effect was more transitory and apparent only in participants with relatively high state-anxiety scores. Practical and theoretical consequences of these findings are discussed.     

Paying attention to reading errors in acquired dyslexia

The important role of selective attention in normal reading is illustrated by a relatively rare form of acquired dyslexia known as 'attentional dyslexia'. Theories of the functional deficit underlying this disorder differ as to the locus of the attentional dysfunction. A recent study by Mayall and Humphreys has contributed to this debate by studying letter migration errors in an attentional dyslexic.     

Spatial attention in Ponzo-like patterns.

A variant of Ponzo's pattern was devised by drawing converging oblique lines at the ends of each of two horizontal lines that were located directly one above the other. Pairs of converging or diverging fins (either between or outside the horizontal shafts) were systematically removed. The results showed that, as predicted by integrative field theory, oblique lines between the shafts produced more distortion than did oblique lines outside the shafts. Also, it was shown that the attentive field construct in integrative field theory was crucial for predicting patterns of means and variances in this experiment. The modified Ponzo effect was shown to have much in common with the classical Müller-Lyer illusion. The subtle differences between the two were explained by proposing that the size of the optimum attentive field was larger in the Ponzo tasks than in the Müller-Lyer tasks because expansion fins are found on both shafts in the Ponzo-like figure.     

Spatial factors in visual attention: a reply to Crassini

Distances between stimuli and, derivatively, compactness of stimulus subsets are pervasive determiners of discrimination and classification performance. Contrary to Crassini (1986), these factors are sufficient to account for the major patterns in the chronometric data of Podgorny and Shepard (1978, 1983). Other factors, such as the dichotomous one distinguishing what Crassini terms unitary and nonunitary subsets, may exert some additional influence. But a convincing demonstration would require formulation of a quantitative model capable of being pitted against the distance-based model of Podgorny and Shepard within the context of their entire body of data.     

Cognitive processes in children's reading and attention: The role of working memory,divided attention,and response inhibition

Children experiencing attention difficulties have documented cognitive deficits in working memory (WM), response inhibition and dual tasks. Recent evidence suggests however that these same cognitive processes are also closely associated with reading acquisition. This paper therefore explores whether these variables predicted attention difficulties or reading among 123 children with and without significant attention problems sampled from the school population. Children were screened using current WM and attention task measures. Three factors explained variance in WM and attention tasks. Response inhibition tasks loaded mainly with central executive measures, but a dual processing task loaded with the visual‐spatial WM measures. Phonological loop measures loaded independently of attention measures. After controls for age, IQ and attention‐group membership, phonological loop and ‘central processing’ measures both predicted reading ability. A ‘visual memory/dual‐task’ factor predicted attention group membership after controls for age, IQ and reading ability. Results thus suggest that some of the processes previously assumed to be predictive of attention problems may reflect processes involved in reading acquisition. Visual memory and dual‐task functioning are, however, purer indices of cognitive difficulty in children experiencing attention problems.     

Basic processes in reading aloud and colour naming: Towards a better understanding of the role of spatial attention

Whether or not lexical access from print requires spatial attention has been debated intensively for the last 30 years. Studies involving colour naming generally find evidence that “unattended” words are processed. In contrast, reading-based experiments do not find evidence of distractor processing. One theory ascribes the discrepancy to weaker attentional demands for colour identification. If colour naming does not capture all of a subject's attention, the remaining attentional resources can be deployed to process the distractor word. The present study combined exogenous spatial cueing with colour naming and reading aloud separately and found that colour naming is less sensitive to the validity of a spatial cue than is reading words aloud. Based on these results, we argue that colour naming studies do not effectively control attention so that no conclusions about unattended distractor processing can be drawn from them. Thus we reiterate the consistent conclusion drawn from reading aloud and lexical decision studies: There is no word identification without (spatial) attention.     

Sensitivity to triadic attention in early infancy

In Study 1, 54 3-, 6- and 9-month-old infants interacted with an adult stranger who engaged in a face-to-face (dyadic) exchange. Dyadic interaction was halted when the adult turned away to look at an object. In a Joint Attention condition, the adult alternated visual attention between the infant and the object, and in a Look Away condition she looked away at the object only. Infants gazed and smiled more in the Joint Attention condition compared to in the Look Away condition. Infants' gazing to the target object interacted with age and condition. In Study 2, 37 3-, 6- and 9-month old infants interacted with an adult who coordinated visual attention and affect, affect only, visual attention only, or ignored the infant. Infants gazed reliably more at E when she coordinated both affect and attention and smiled reliably more when the adult coordinated affect and attention or attention only. The findings show a sensitivity to triadic attention by 3 months of age.     

Spatial attention in vision

Summary Human observers can selectively allocate processing resources to different areas of the visual field within a single fixation. This spatial attention system may affect either the quality of information extraction or the decisions and responses based on this information. This paper reviews evidence from behavioral, single-unit, and event-related potential paradigms; the evidence suggests a relatively early locus of spatial attention.This research was supported by the U. S. Army Research Office under contract DAAG 29-83-K-0049. Portions of this paper were presented to the Conference on Attention and Action, Bielefeld, West Germany, in July 1985     

Processing of a speech signal and thereby necessary attention: a contribution to dual performance

Speech intelligibility during the performance of a second task (sorting of small plates), and the frequency of sorting in dependence of the phases of speech processing (input-processing-output) are investigated. A fixed speech level (65 dB) is combined with 5 different noise levels (55, 60, 65, 70, 75 dB). The speech material and the sorting task vary in difficulty (words, sentences, small texts; simple and complicated sorting). By rating 3 questions the subjective quality of both tasks is inquired. Main results: speech intelligibility and frequency of sorting vary in dependence of noise level; frequency of sorting varies in dependence of the phases of speech processing and speech material; subjective ratings are corresponding with the performance of both tasks.     

Allocation of attention, reading skills, and deafness.

Brannan and Williams (1987) found that poor readers cannot successfully utilize parafoveal cues to identify letter targets. Whether a similar deficit in the use of cue information occurs in deaf poor readers and whether it is only specific to processes that capture attention automatically were investigated in congenitally deaf young adults classified as poor or good readers and hearing controls classified as good readers. Subjects were presented with central or parafoveal cues that varied in cue validity probability, followed by letter targets presented to the left or right of fixation. The reaction time data analyses showed significant main effects for cue type and cue location and significant interactions among cue type, cue location, cue validity probability, and visual field. No significant main effect or interactions involving groups were found. These results raise the possibility that reading difficulties associated with deafness do no involve a deficit in the visual attentional system of deaf people. They also confirm that parafoveal cues are more effective than central cues in capturing attention.     

Spatial constraints on attention to speech in the blind

When sighted persons try to identify one of two speech utterances coming from different directions, they display both a frontal position advantage, i.e., better recognition of inputs from the front than of those from the rear, and a right-side advantage, better recognition of inputs from the right than of those from the left. The present study demonstrates a dissociation of the two effects in blind subjects (N = 10) who showed no frontal position advantage together with a right-side advantage superior to that of control sighted subjects (N = 16). There was no systematic difference between congenitally blind subjects and noncongenitals. The absence of frontal position advantage in the blind is consistent with the notion that this effect originates in the habit of sighted listeners to orient toward the source of heard speech. The occurrence of at least normal right-side advantage in the blind does not support recent suggestions of reduced lateralization of language functions in such subjects.