Visual search for arbitrary objects in real scenes

How efficient is visual search in real scenes? In searches for targets among arrays of randomly placed distractors, efficiency is often indexed by the slope of the reaction time (RT) × Set Size function. However, it may be impossible to define set size for real scenes. As an approximation, we hand-labeled 100 indoor scenes and used the number of labeled regions as a surrogate for set size. In Experiment 1, observers searched for named objects (a chair, bowl, etc.). With set size defined as the number of labeled regions, search was very efficient (~5 ms/item). When we controlled for a possible guessing strategy in Experiment 2, slopes increased somewhat (~15 ms/item), but they were much shallower than search for a random object among other distinctive objects outside of a scene setting (Exp. 3: ~40 ms/item). In Experiments 4–6, observers searched repeatedly through the same scene for different objects. Increased familiarity with scenes had modest effects on RTs, while repetition of target items had large effects (>500 ms). We propose that visual search in scenes is efficient because scene-specific forms of attentional guidance can eliminate most regions from the “functional set size” of items that could possibly be the target.     

Supervaluationism and Logical Consequence: A Third Way

It is often assumed that the supervaluationist theory of vagueness is committed to a global notion of logical consequence, in contrast with the local notion characteristic of modal logics. There are, at least, two problems related to the global notion of consequence. First, it brings some counterexamples to classically valid patterns of inference. Second, it is subject to an objection related to higher-order vagueness. This paper explores a third notion of logical consequence, and discusses its adequacy for the supervaluationist theory. The paper proceeds in two steps. In the first step, the paper provides a deductive notion of consequence for global validity using the tableaux method. In the second step, the paper provides a notion of logical consequence which is an alternative to global validity, and discusses i) whether it is acceptable to the supervaluationist and ii) whether it plays a better role in a theory of vagueness in the face of the problems related to the global notion.     

In search of depth

Four experiments designed to investigate a visual search task are reported. In each experiment, subjects searched for either a two-dimensional shape rotated in depth among frontal-parallel distractors or a frontal-parallel shape among distractors that were rotated in depth. The principal independent variable was search-set size. In addition, over the four experiments, a variety of spatial arrangements and two axes of rotation in depth were sampled. The chief aim of the experiments was to adduce evidence bearing on the attentional demands of searching for depth. The slopes of the reaction-time (RT) functions were taken as diagnostic. Experiments 1-3 exhibited positive slopes for the RT-set-size function. These slopes appear to be due to a conscious adoption of a serial search strategy by the subjects. When this tendency was suppressed by the procedures of Experiment 4, the slope of the RT-set-size functions did not differ significantly from zero. We conclude that, in agreement with the findings of other studies, slant-in-depth can be detected preattentively.     

In search of ambiguity

A study of the time required for Ss to perceive the two meanings of ambiguous sentences, supports the following conclusions: (I) Perception time (PT) is a function of the type of ambiguity, three of which are defined in this study. (2) A similar relative function was obtained for thePT in sentences with more than one ambiguity and for sentences with only a single ambiguity. (3) ThePT for finding a single ambiguity in such multiply ambiguous sentences was significantly longer than in singly ambiguous sentences. (4) When one of the interpretations of certain types of ambiguous sentences is less likely than the other (where likeliness is defined in terms of the number of Ss perceiving that inter-pretation first)PT is high. (5) Complexity of the surface and underlying structures (which are defined in transformational grammar) is an important determinant of thePT for surface and underlying structure ambiguities, respectively.     

In search of depth

Four experiments designed to investigate a visual search task are reported. In each experiment, subjects searched for either a two-dimensional shape rotated in depth among frontal-parallel distractors or a frontal-parallel shape among distractors that were rotated in depth. The principal independent variable was search-set size. In addition, over the four experiments, a variety of spatial arrangements and two axes of rotation in depth were sampled. The chief aim of the experiments was to adduce evidence bearing on the attentional demands of searching for depth. The slopes of the reaction-time (RT) functions were taken as diagnostic. Experiments 1–3 exhibited positive slopes for the RT-set-size function. These slopes appear to be due to a conscious adoption of a serial search strategy by the subjects. When this tendency was suppressed by the procedures of Experiment 4, the slope of the RT-set-size functions did not differ significantly from zero. We conclude that, in agreement with the findings of other studies, slant-in-depth can be detected preattentively.     

In search of a strong visual recency effect

When a sequence of visual stimuli is presented in a fixed location, immediate serial recall of the sequence is characterized by only a small recency effect. According to Battacchi, Pelamatti, and Umiltà (1990), the distribution of visual stimuli over space, as well as time, greatly enhances the recency effect. After an initial failure to find a strong visual recency effect with distributed presentation (Experiment 1), in the remaining experiments an attempt was made to more closely approximate Battacchi et al.'s methodology by eliminating articulatory suppression (Experiments 2-7), using their stimuli (Experiments 3-7), blocking conditions (Experiments 4-7), requiring written rather than typed responses (Experiments 5-7), and using their list length (Experiments 6 and 7). Nevertheless, even when their method was followed as closely as possible (Experiment 7), distributed presentation did not produce a strong visual recency effect. The influence of distributed presentation on the visual recency effect would seem to be, at best, limited.     

In search of perceptual priming in a semantic classification task

Four experiments tested for perceptual priming for written words in a semantic categorization task. Repetition priming was obtained for low-frequency words when unrelated categorizations were performed at study and test (Experiment 1), but it was not orthographically mediated given that written-to-written and spoken-to-written word priming was equivalent (Experiments 2 and 3). Furthermore, no priming was obtained between pictures and words (Experiment 4), suggesting that the nonorthographic priming was largely phonological rather than semantic. These results pose a challenge to standard perceptual theories of priming that should expect orthographic priming when words are presented in a visual format at study and test.     

In search of cross-talk facilitation in a dual-cued recall task

Despite earlier evidence that the presence of 2 redundant cues can facilitate activation of a common response, T. C. Rickard and D. Bajic (2004) found no dual-cue facilitation in the case of cued recall, provided that each cue-response association was learned independently. In this study the authors investigated the generality of their results using a dual-task cross-talk design. There was no evidence of dual-cue facilitation for compatible cue trials in the case of associative independence. Race models as well as at least some limited capacity parallel retrieval accounts can be eliminated by these and related results. It appears instead that a preretrieval stage performance bottleneck precludes cued recall through more than 1 independently represented cue-response association at a time.     

爵禄或刑罚之外的第三条道路

稷下先生们的身份不是官僚而是学者,因此,对于齐国的灭亡,他们不应承担任何责任。这一责任当然应由统治者来承担,这一点不容混淆。秦国的统一非常短暂,对其胜利的意义不宜无限夸大。秦亡除了不重视文化,最直接的原因是其法家政策。典型的法家思维认为,君主以外的任何人若想生存,无非“爵禄或刑罚”两条道路,这是非常愚昧的专制、集权思想,必须建立起“市民社会”以制衡之。     

In search of remembrance: evidence for memory in visual search

Observers searched for a target among distractors while the display items traded places every 110 ms. Search was slower when the target was always relocated to a position previously occupied by a distractor than when the items remained in place, showing the importance of memory for locations in a visual search task. Experiment 2 repeated a previous study in which items could move to any location within the display, but used a larger range of set sizes than tested in the earlier study. A cost in search times to relocating items was found at the larger set sizes, most likely reflecting that the probability that the target would replace a distractor increased witht he set size. The findings provide strong evidence for the role of memory for locations within trials in a visual search task.     

Pastoral counseling: In search of a new paradigm

Contemporary pastoral counseling includes three paradigmatic elements: the image of the counselor as priest; the location of the human problem at the organismic-environmental interface; and the diagnosis of the human problem as alienation from self and others. These assumptions ought to be supplemented by the image of the counselor as prophet, by location of the human problemalso at the interface of the self and the ultimate, and by a diagnosis of the human problem as alienation from transcendence. To be adequate as a response to the total human situation, pastoral counseling theory must be expanded to include consideration of the transcendent dimension of human existence, and pastoral counseling method and technique must be modified to overcome alienation from the ultimate by facilitating the actualization of transcendence.His article is a revision of the keynote address he presented to the American Association of Pastoral Counselors at their annual meeting in May 1976.