A gradual spread of attention during mental curve tracing

The visual system has to segregate objects that are relevant to behavior from other objects and the background, if they are embedded in a visual scene. This segregation process can be time consuming, especially if the relevant object is spatially extended and overlaps with other image components, but the cause of the delays is presently not well understood. In the present study, we used a curve-tracing task to investigate processing delays during the grouping of contour segments into elongated curves. Our results indicate that contour segments that need to be grouped together are labeled with visual attention. Attention gradually spreads from contour segments that were labeled previously to other contours that are colinear and connected to them. The contour-grouping task is completed as soon as attention is directed to the entire curve. We conclude that processing delays during contour grouping are caused by a time-consuming spread of visual attention.     

Top-down control of attention: it's gradual, practice-dependent, and hierarchically organized

When searching for a "pop-out" target, interference from a salient but irrelevant distractor can be reduced or even prevented under certain circumstances. Here, five experiments were conducted to further our understanding of three different aspects of top-down interference reduction: first, whether or not qualitatively different search modes can account for different reduction patterns; second, whether distractor practice plays a causal role in reduction; and third, how specific reduction is, that is, whether interference by intradimensional distractors can be reduced as effectively as interference by cross-dimensional distractors. The results provide evidence that interference reduction does not critically depend on the implementation of a feature search mode, but rather on practice with the distractor, that is, the acquisition of an effective suppression strategy. In addition, they suggest that interference reduction is based on hierarchically organized feature weighting ("dimension weighting"), rather than on completely independent feature weighting.     

Attentional awakening: gradual modulation of temporal attention in rapid serial visual presentation

Orienting attention to a point in time facilitates processing of an item within rapidly changing surroundings. We used a one-target RSVP task to look for differences in accuracy in reporting a target related to when the target temporally appeared in the sequence. The results show that observers correctly report a target early in the sequence less frequently than later in the sequence. Previous RSVP studies predicted equivalently accurate performances for one target wherever it appeared in the sequence. We named this new phenomenon attentional awakening, which reflects a gradual modulation of temporal attention in a rapid sequence. This study was supported by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science awarded to Kazuhiko Yokosawa.     

The spread of attention to hidden portions of occluded surfaces

We report two experiments in which the two-rectangles method of Egly, Driver, and Rafal (1994) was used to test whether object-specific attentional cuing advantages can spread to hidden portions of occluded objects. Displays began with portions of two rectangles hidden by a third, occluding object. One end of one of the two rectangles was cued, after which the occluder rotated around its center point and target stimuli were presented. In one condition, the occluder was removed from in front of the other objects, either by rotating away from them (Experiment 1B) or by rotating and then slipping behind them (Experiment 1B). In another condition, the occluder first rotated away but then returned to its original position. In both experiments, an object-specific cuing advantage occurred in the occluderremoved condition for targets that appeared in what had been hidden locations of the cued object. No analogous advantage occurred in the occluder-returned condition.     

A feature-integration theory of attention

A new hypothesis about the role of focused attention is proposed. The feature-integration theory of attention suggests that attention must be directed serially to each stimulus in a display whenever conjunctions of more than one separable feature are needed to characterize or distinguish the possible objects presented. A number of predictions were tested in a variety of paradigms including visual search, texture segregation, identification and localization, and using both separable dimensions (shape and color) and local elements or parts of figures (lines, curves, etc. in letters) as the features to be integrated into complex wholes. The results were in general consistent with the hypothesis. They offer a new set of criteria for distinguishing separable from integral features and a new rationale for predicting which tasks will show attention limits and which will not.     

A theory of visual attention

A unified theory of visual recognition and attentional selection is developed by integrating the biased-choice model for single-stimulus recognition (Luce, 1963; Shepard, 1957) with a choice model for selection from multielement displays (Bundesen, Pedersen, & Larsen, 1984) in a race model framework. Mathematically, the theory is tractable, and it specifies the computations necessary for selection. The theory is applied to extant findings from a broad range of experimental paradigms. The findings include effects of object integrality in selective report, number and spatial position of targets in divided-attention paradigms, selection criterion and number of distracters in focused-attention paradigms, delay of selection cue in partial report, and consistent practice in search. On the whole, the quantitative fits are encouraging.     

A gradual reformation: empirical character and causal powers in Kant

According to Kant each person has an empirical character, which is ultimately grounded in one’s free choice. The popular Causal Laws interpretation of empirical character holds that it consists of the causal laws governing our psychology. I argue that this reading has difficulties explaining moral change, the ‘gradual reformation’ of our empirical character: Causal laws cannot change and hence cannot be gradually reformed. I propose an alternative Causal Powers interpretation of empirical character, where our empirical character consists of our mind’s causal powers. The resulting picture of empirical character allows for moral change and Kantian weakness of will.     

A psychometric comparison of anxiety-relevant attention measures

Background and Objectives: Preferential attention to threat, emotional response inhibition, and attentional control each purportedly play a key role in anxiety disorders. Divergent psychometric properties among attention measures may produce differential detection of anxiety-related associations and treatment-related changes. However, no studies have directly compared the psychometric properties of these attention measures in the same sample.

Design: Eighty-five young adults (M?=?19.41 years, SD?=?1.47, 48 Females) completed a cognitive task battery and a subset of 60 participants (M?=?19.42 years, SD?=?1.48, 33 Females) completed the task battery again approximately two weeks later.

Method: To assess preferential attention to threat, emotional response inhibition, and attentional control, the cognitive task battery included a dot-probe task, emotion and gender Stroop tasks, and a flanker task. Tasks varied in how attention was directed and if emotional stimuli were included. Internal consistency and test-retest reliability were compared across measures.

Results: Within the same sample, internal consistency and reliability differed across attention measures. Explicit attention measures (emotional Stroop and flanker) exhibited stronger internal consistency and greater test-retest reliability compared to implicit measures (dot-probe and gender Stroop).

Conclusions: These results inform clinical research using attention measures to assess anxiety-related differences and treatment response.     

A Boolean map theory of visual attention

A theory is presented that attempts to answer two questions. What visual contents can an observer consciously access at one moment? Answer: only one feature value (e.g., green) per dimension, but those feature values can be associated (as a group) with multiple spatially precise locations (comprising a single labeled Boolean map). How can an observer voluntarily select what to access? Answer: in one of two ways: (a) by selecting one feature value in one dimension (e.g., selecting the color red) or (b) by iteratively combining the output of (a) with a preexisting Boolean map via the Boolean operations of intersection and union. Boolean map theory offers a unified interpretation of a wide variety of visual attention phenomena usually treated in separate literatures. In so doing, it also illuminates the neglected phenomena of attention to structure.     

The organization of attention in typical development: A new preschool attention test battery

This article introduces a new battery of attention tests for typically developing and atypically developing children with a mental age of 3–6 years. In the light of adult and child studies supporting a model of distinct networks for specific attentional operations, tests in the current battery were selected with the aim of measuring functions of selective attention, sustained attention and attentional control (executive function). Normative data were collected from 154 typically developing children aged 3–6 years and examined using exploratory factor analysis to determine latent constructs underlying test performance. This analysis suggested increasing differentiation of attention functions over the age range, with support for the hypothesized three‐factor model only after 4½ years of age. Additional analyses supported the validity of the new attention battery with respect to (1) parent/teacher report measures of everyday attention behaviour and (2) later performance on the Test of Everyday Attention for Children (TEA‐Ch), a battery designed for children aged 6–16 years. The results show the developing differentiation of attention functions and support the ecological and predictive validity of the battery as providing early performance‐based measures of attention and an attention ‘profile’ for each individual child, which may aid characterization and remediation of neurodevelopmental disorders.     

Human non-visual discrimination of gradual turning is poor

We report three measures of the ability of normally sighted adults to discriminate turning while walking blindfolded outdoors. Constant error in selecting line drawings of paths indicated that participants under represent the amount of turning along more curved paths and over represent the amount of turning on less curved paths. Constant error in the direction of pointing to the origin of paths indicated a bias consistent with the direction of turning along more curved paths. Participants produced more accurate drawings of paths as the amount of turning increased. The results suggest that non-visual cues that accompany self movement are not sufficient for accurate representation of large radius curves in geographic scale travel.     

Action blindness in response to gradual changes

The goal of this study is to characterize observers’ abilities to detect gradual changes and to explore putative dissociations between conscious experience of change and behavioral adaptation to a changing stimulus. We developed a new experimental paradigm in which, on each trial, participants were shown a dot pattern on the screen. Next, the pattern disappeared and participants had to reproduce it. In some conditions, the target pattern was incrementally rotated over successive trials and participants were either informed or not of this change. We analyzed both awareness of the changes and the dynamics of behavioral adaptation, in a way that makes it possible to assess both variability and accuracy as they change over time. Results indicate a dissociation between change awareness and behavioral adaptation to the changes, and support the notion that unconscious representations of visual stimuli are more precise and detailed than previously suggested. We discuss the implications of these results for theories of change detection.     

Selective attention and secondary message analysis: A reconsideration of Broadbent's filter model of selective attention

If the type of channel sharing which Broadbent (1958) hypothesized for low information messages also occurs with high information verbal messages, then his filter model is an adequate model of the selective attention process. Analysis which proceeds by a hierarchy of tests and the fluctuating redundancy of primary prose messages can together account for the characteristics of secondary message detection. This hypothesis was tested using four levels of redundancy in the primary message, and two types of secondary message targets, requiring analysis to two different levels in the hierarchy of tests for detection. It was predicted that there should be more target detection as redundancy increased, and more detection of the targets requiring the lower level of analysis than of those requiring the higher. The predictions were confirmed with the exception that the higher level targets were detected with equal frequency at all levels of redundancy. A possible reason for this is suggested.     

Capturing attention when attention blinks

Four experiments addressed the question of whether attention may be captured when the visual system is in the midst of an attentional blink (AB). Participants identified 2 target letters embedded among distractor letters in a rapid serial visual presentation sequence. In some trials, a square frame was inserted between the targets; as the only geometric object in the sequence, it constituted a singleton. Capture effects obtained when the AB was most severe and when it was over were compared. There were 3 main results. First, capture occurred even when the AB was crippling, suggesting that a singleton exogenously engaged attention even when processing of a previous target was continuing apace. Second, when the singleton contained the key target feature, capture effects were clearly manifest. Third, even when the singleton did not possess the key target feature, it still succeeded in capturing attention, although the effects were both feeble and fleeting.