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The development of reflexive and voluntary shifts of visual attention, as well as relations between the two forms of shifting was examined in three groups of children (5-, 7-, and 9-years-old), one group of young adults (24-years-old), and two groups of senior adults (young seniors: 69-years-old, old seniors: 81-years-old). The task entailed the detection and response to the presentation of a target (black dot) in one of four possible locations in the visual field. The dependent measure was reaction time (RT). The extent to which flash cues facilitated or inhibited reflexive orienting was determined through presentation of nonpredictive abrupt onset peripheral flash cues prior to the target. Arrow facilitation and inhibition was measured by shifts of attention initiated in response to predictive central arrow cues. Relations between reflexive and voluntary shifts of attention were gauged by the degree to which flash and arrow facilitation and inhibition were observed in response to the presentation of both arrow and flash cues together in one trial. Conditions varied with regard to the validity of the location cues (accurate or inaccurate information regarding the location of the subsequent target) and the length of the interval between the cue and the target (SOA: 185 or 875 ms). All age groups demonstrated flash facilitation with the flash cue alone, demonstrating similar patterns of reflexive orienting across the lifespan. However, the three groups of children demonstrated the largest flash cue effects suggesting that they had the most difficulty ignoring the nonpredictive flash cues. With the arrow cue alone, young adults, and young and old senior adults were more efficient (faster RTs) in their execution of voluntary shifts, however, all age groups utilized the arrow cues to orient attention strategically and in doing so experienced similar patterns of arrow facilitation. When both flash and arrow cues were presented together, the 9-year-old children, young

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Twelve spatial-cueing experiments examined stimulus-driven and goal-driven control of visual attention orienting under multiple-cue conditions. Spatial cueing involves presenting a cue at a potential target location before a target appears in a display, and measuring the cue's effect on responses to the target stimulus. Under certain conditions, a cue that appears abruptly in a display (direct cue) can speed responses to a target appearing at the previously cued location relative to other uncued locations (called the cue effect). The experiments in this dissertation used a new multiple-cue procedure to decouple the effects of stimulus-driven and goal-driven processes on the control of attention. This technique involved simultaneously presenting a red direct cue (Unique Cue) that was highly predictive of the target location along with multiple grey direct cues (Standard Cues) that were not predictive of the target location. The basic finding was that while cue effects occurred at all cued locations, they were significantly larger at the Unique-Cue location. This finding was interpreted as evidence for stimulus-driven cue effects at all cued locations with additional goal-driven cue effects at the Unique-Cue location. Further experiments showed that Standard-Cue effects could occur independently at multiple locations, that they seemed to involve a sensory-based interaction between the cues and the target, and that they were mediated by a limitedcapacity tracking mechanism. In addition, Unique-Cue effects were found to be the product of goal-driven operations, to interact with Standard-Cue effects, and to involve inhibited processing at unattended locations. These results were explained in terms of a filter-based model of attention control that assigns priority to potential attention-shift destinations. According to this model, stimulus-driven and goal-driven factors generate signals (activity distributions) that drive a filter to open an attention channel at the highest priority location by suppressing the signals at other locations. The final experiments confirmed the central assumptions of this model by providing evidence that the prioritydestination process was sufficient to produce cue effects independent of attention, and that attending to a location involved a suppression of processing at unattended locations. The implications of this model for the larger visual attention literature were also discussed.

A considerable amount of research exists on the subjective perception of three-dimensional structure from texture gradients. The present set of experiments extends these tests of phenomenal perception by examining the underlying processes used in interpreting slant-from-texture. The first two experiments show that measures of subjective perception predict speeded performance in a visual search task, and that the mediating representation relies on an assumption of projective size (i.e., discriminating the size of the target is difficult when the short target is far or the long target is near). The third experiment shows that sensitivity to apparent depth in the texture display is present even in rapid and parallel search conditions where early vision is known to operate. The fourth experiment assesses the relative contribution of two dominant dimensions of the texture gradient -- "perspective" (i.e., a radial pattern) and "compression" (i.e., a foreshortened pattern). Both dimensions are detected by early vision as signals for apparent depth. The fmal experiment examines how early vision codes these two dimensions. Sternberg's (1969) Additive Factors Method (AFM) is used to assess separability of encoding, and Blalock's path analysis (1962, 1985) is used to examine the order of encoding. AFM shows that perspective and compression have independent influences on search performance in the most rapid search conditions, but that their interaction increases as search slows. The path analysis shows further that when both texture dimensions are available, perspective exerts a more immediate and perhaps even an exclusive influence on performance. These findings support the view that perspective and compression are coded separately at the earliest stages of visual processing and share a common code only later in visual processing.

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This thesis claims that metacontrast unmasking is influenced by attentional orienting towards the target location. This view is contrary to Breitmeyer, Rudd and Dunn (1981), who proposed that metacontrast unmasking is the product of inhibition of the primary mask's transient signal by the sustained signal of a secondary mask. A series of experiments demonstrate the thesis using a task in which observers discriminated the missing corner of a target diamond. Experiments 1 and 2 replicated metacontrast masking and unmasking, respectively, experiment 3 illustrated that contour proximity had no influences on unmasking, contrary to dual-channel inhibition theory. Experiments 4 and 5 indicated that metacontrast unmasking was influenced by spatial orienting. We propose an addition of attention to dual-channel theory as it is incomplete with regards to metacontrast unmasking.

The detection of human and non-human animals and their unique (and potentially dangerous) “animation” would have been important to our ancestors’ survival. It would seem plausible that our ancestors would have required a vigilance above and beyond that dedicated to other, inanimate, objects. Considering the millions of years of expending extra energy to monitor these objects, it would also seem likely, at least as advocated by New, Cosmides, and Tooby (2007), that the human visual system would have developed mechanisms to allocate attention automatically and quickly to these objects. We tested the New et al. (2007) “animate monitoring” hypothesis by presenting viewers with a group of animate objects and a group of inanimate objects using the flicker task—a task that is assumed to be one that measures automatic visual attention. These objects were presented on a variety of backgrounds of natural scenes, including some backgrounds that were contextually inconsistent with the target objects. These objects were also presented in either a consistent location within each scene or a location that violated that consistency. Only people objects were consistently more readily detected, not animated objects in general. Detection in this task was affected by more than just the information provided by the target object. Both results provide a serious challenge to the “animate monitoring” hypothesis. Furthermore, the results were shown not to be due to peculiarities of our stimulus set, or by how interesting the members of each object category were. iv / xii, 108 leaves ; 29 cm

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