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181.
Attention capacity and task difficulty in visual search   总被引:1,自引:0,他引:1  
Huang L  Pashler H 《Cognition》2005,94(3):B101-B111
When a visual search task is very difficult (as when a small feature difference defines the target), even detection of a unique element may be substantially slowed by increases in display set size. This has been attributed to the influence of attentional capacity limits. We examined the influence of attentional capacity limits on three kinds of search task: difficult feature search (with a subtle featural difference), difficult conjunction search, and spatial-configuration search. In all 3 tasks, each trial contained sixteen items, divided into two eight-item sets. The two sets were presented either successively or simultaneously. Comparison of accuracy in successive versus simultaneous presentations revealed that attentional capacity limitations are present only in the case of spatial-configuration search. While the other two types of task were inefficient (as reflected in steep search slopes), no capacity limitations were evident. We conclude that the difficulty of a visual search task affects search efficiency but does not necessarily introduce attentional capacity limits.  相似文献   
182.
The objective of this paper is to show how potentially incomplete preferences of a decision maker (DM) on acts can be modelled formally in a subjective ambiguity perspective. We identify acts as functions from a state space Ω to bounded support (finitely additive) probabilities over a set X of prizes. Then, we characterize preferences over equibounded acts a which have a numerical representation by the family of functionals , where u is a cardinal utility on X (representing the risk attitude of the DM) and Π is a unique pointwise closed convex set of probabilities on all events in Ω (representing the ambiguity perceived by the DM). To this end, in addition to the usual independence and continuity assumptions, we add completeness and dominance for preferences restricted to constant acts; moreover, we consider two other properties (subjective monotonicity and coherence) related with the preferences of a DM who is not able, owing to his partial knowledge, to evaluate any event in Ω.  相似文献   
183.
This paper will focus on the writer’s experience as a native New Yorker relocating to Montgomery, Alabama. The writer will share how he adjusted and coped with overt discrimination and racism in the context of the high school in which he attended there-a majority white high school on the “other” side of town. The writer will share how he employed the following coping mechanisms as methods of adjusting to his new environment: translating emotional experiences into words (relaxation and talk therapy), involvement with other black positive peers, careful assessment before acting, withdrawal and avoidance, and consuming African-American literature.  相似文献   
184.
Neural correlates of a default response in a delayed go/no-go task   总被引:3,自引:0,他引:3  
Working memory, the ability to temporarily retain task-relevant information across a delay, is frequently investigated using delayed matching-to-sample (DMTS) or delayed Go/No-Go tasks (DGNG). In DMTS tasks, sample cues instruct the animal which type of response has to be executed at the end of a delay. Typically, performance decreases with increasing delay duration, indicating that working memory fades across a delay. However, no such performance decrease has been found when the sample cues exist of present vs. absent stimuli, suggesting that pigeons do not rely on working memory, but seem to respond by default in those trials. We trained 3 pigeons in a DGNG task and found a similar default response pattern: The diverging slopes of the retention functions on correct Go and No-Go trials suggested that pigeons by default omitted their response following No-Go stimuli, but actively retained task-relevant information across the delay for successful responses on Go trials. We conducted single-cell recordings in the avian nidopallium caudolaterale, a structure comparable to the mammalian prefrontal cortex. On Go trials, many neurons displayed sustained elevated activity during the delay preceding the response, replicating previous findings and suggesting that task-relevant information was neurally represented and maintained across the delay. However, the same units did not show enhanced delay activity preceding correct response suppressions in No-Go trials. This activation-inactivation pattern presumably constitutes a neural correlate of the default response strategy observed in the DGNG task.  相似文献   
185.
The purpose of this article is to offer pastoral reflections on the movie by Mel Gibson entitled The Passion of the Christ.  相似文献   
186.
The fixed point combinator (Y) is an important non-proper combinator, which is defhable from a combinatorially complete base. This combinator guarantees that recursive equations have a solution. Structurally free logics (LC) turn combinators into formulas and replace structural rules by combinatory ones. This paper introduces the fixed point and the dual fixed point combinator into structurally free logics. The admissibility of (multiple) cut in the resulting calculus is not provable by a simple adaptation of the similar proof for LC with proper combinators. The novelty of our proof—beyond proving the cut for a newly extended calculus–is that we add a fourth induction to the by-and-large Gentzen-style proof. Presented by Robert Goldblatt  相似文献   
187.
Not only do the writings of Nietzsche – early and late – fail to support the pedagogy of self-reformulation, this doctrine embodies what for him is worst in man and would destroy that which is higher. The pedagogy of self-reformulation is also incoherent. In contrast, Nietzsche offers a fruitful and comprehensive theory of education that, while non-democratic and contemptuous of egalitarian aspirations, emerges consistently from his metaphysics and philosophical anthropology. Whatever, then, we might think of his premises, Nietzsche’s philosophy of education represents an attractive model for those who would develop a meaningful, distinctive, and persuasive educational theory. It defines a domain of the possible and then straightforwardly states what is and is not to be done within it – and why.  相似文献   
188.
Previous studies reveal the reinforcement of gender stereotypes by picture books children read during the formative years. In these books, boys tend to be portrayed as active leaders, and girls as passive followers. Women and girls are under-represented. Men often exhibit career skills, and women perform traditional tasks in the home. Even when careers are nontraditional, personality characteristics and other qualities and behaviors are often stereotypical. Previous researchers emphasized the narrowly defined roles of women and children in picture books. In this study, we focused on the representation of mothers and fathers, and examined whether men are stereotyped as relatively absent or inept parents. A content analysis of the gender roles exhibited in 200 prominent childrens picture books demonstrated that fathers are largely under-represented, and, when they do appear, they are withdrawn and ineffectual parents. Further research could establish whether seriously deficient models of fatherhood in childrens literature affect the incidence of present, caring fathers in society.  相似文献   
189.
There is currently controversy over the validity and applicability of functional behavioral assessment (FBA) procedures with students with emotional/behavioral disorders (E/BD). A set of FBA procedures, including teacher and student interviews and direct classroom observations, were carried out with eight students with disabilities (7 classified E/BD, one classified LD). Results indicated that when all three methods (teacher/student interviews, classroom observations) yielded a ranking for a function they agreed 64% of those occasions. For those situations in which there was overall disagreement there was agreement between teacher interview and classroom observations most of the time. Social validity data indicated that both students and teachers felt that the assessment procedures were a useful and productive process.  相似文献   
190.
Cognitive deficits associated with early Alzheimers disease (AD) have been recently operationalised in terms of an acquisition deficit and the research supporting this view is presented. However, there is still debate concerning the nature of this deficit and how underlying cognitive processes may be detrimentally affecting the ability to acquire new information in early AD. This review argues that the pattern of cognitive deficits contributing to the acquisition impairment in early AD patients may be readily interpreted within the context of a working memory model. Isolating the component processes of working memory that underlie the acquisition deficit in early AD patients will aid in the design of clinical applications that are focussed at enhancing the ability to acquire new information in everyday life.  相似文献   
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