Current concerns in visual masking.

Theories of emotion postulate that emotional input is processed independently from perceptual awareness. Although visual masking has a long tradition in studying whether emotional pictures are processed below a supposed threshold of perceptual awareness (subliminal perception), a consensus has yet to be reached. This article reviews current concerns in the use of visual masking. These include a reliable presentation method, the role of masking pictures, common definitions of awareness and their problems, current models of awareness, and neural mechanisms. A useful strategy may be the study of dose-response relationships between awareness and emotion processing that avoids a dichotomous view of awareness and allows conclusions about the relative independence of emotional processing from awareness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Unconscious vigilance: Worldview defense without adaptations for terror, coalition, or uncertainty management.

Individuals subtly reminded of death, coalitional challenges, or feelings of uncertainty display exaggerated preferences for affirmations and against criticisms of their cultural in-groups. Terror management, coalitional psychology, and uncertainty management theories postulate this “worldview defense” effect as the output of mechanisms evolved either to allay the fear of death, foster social support, or reduce anxiety by increasing adherence to cultural values. In 4 studies, we report evidence for an alternative perspective. We argue that worldview defense owes to unconscious vigilance, a state of accentuated reactivity to affective targets (which need not relate to cultural worldviews) that follows detection of subtle alarm cues (which need not pertain to death, coalitional challenges, or uncertainty). In Studies 1 and 2, death-primed participants produced exaggerated ratings of worldview-neutral affective targets. In Studies 3 and 4, subliminal threat manipulations unrelated to death, coalitional challenges, or uncertainty evoked worldview defense. These results are discussed as they inform evolutionary interpretations of worldview defense and future investigations of the influence of unconscious alarm on judgment. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A Combi-Stroop test for measuring food-related attentional bias.

There are methodological complexities with the supraliminal–lexical versions of the modified versions of the Stroop tests that could be responsible for inconsistencies across the literature (Field & Cox, 2008). We tested whether a combination of subliminal–pictorial and classic Stroop tests can differentiate between dieters' and nondieters' food attentional bias (FAB). Participants were dieters (n = 30) and nondieters (n = 32) who were tested 3 hr after having a meal. Each picture from among 24 high-calorie and 24 low-calorie food pictures was presented for 32 ms before the appearance of a congruent or an incongruent color word, in response to which participants were required to manually report, via a tagged keyboard, the correct color of the word as quickly and accurately as possible. Color-naming latencies and interference scores were calculated. Dieters showed the highest reaction times to incongruent color words following high-calorie food pictures; overall, dieters showed significantly higher FABs than nondieters. The Combi-Stroop test has differential validity. Moreover, findings suggest that FAB can result from early allocation of dieters' attention to food-related stimuli. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Long-term semantic memory versus contextual memory in unconscious number processing.

Subjects classified visible 2-digit numbers as larger or smaller than 55. Target numbers were preceded by masked 2-digit primes that were either congruent (same relation to 55) or incongruent. Experiments 1 and 2 showed prime congruency effects for stimuli never included in the set of classified visible targets, indicating subliminal priming based on long-term semantic memory. Experiments 2 and 3 went further to demonstrate paradoxical unconscious priming effects resulting from task context. For example, after repeated practice classifying 73 as larger than 55, the novel masked prime 37 paradoxically facilitated the "larger" response. In these experiments task context could induce subjects to unconsciously process only the leftmost masked prime digit, only the rightmost digit, or both independently. Across 3 experiments, subliminal priming was governed by both task context and long-term semantic memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Activation of the attachment system in adulthood: Threat-related primes increase the accessibility of mental representations of attachment figures.

Three studies explored the effects of subliminal threat on the activation of representations of attachment figures. This accessibility was measured in a lexical decision task and a Stroop task following threat- or neutral-word primes, and was compared with the accessibility of representations of other close persons, known but not close persons, and unknown persons. Participants also reported on their attachment style. Threat primes led to increased accessibility of representations of attachment figures. This effect was specific to attachment figures and was replicated across tasks and experiments. Attachment anxiety heightened accessibility of representations of attachment figures even in neutral contexts, whereas attachment avoidance inhibited this activation when the threat prime was the word separation. These effects were not explained by trait anxiety. The discussion focuses on the dynamics of attachment-system activation in adulthood. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

使用阈下信道的可逆R-S数字水印

由于难以获得足够的冗余水印容量,一些面向内容认证的可逆水印方案仅嵌入了用对称算法加密的杂凑值,它的数据尺寸显著地小于数字签名,但这使不诚实的验证者能伪造合法的内容.然而研究发现,虽然当前公钥签名的长度是杂凑值的数倍,但通过使用阈下信道,在方案中引入公钥签名仅需增加数个字节的容量.据此,一个改进的R-S(regular-singular)可逆数字水印方案被提出,它采用RSAPSS公钥签名,并利用签名中阈下信道存储部分或全部压缩的R-S向量.该方案仅需增加4个字节的额外水印容量,也具有篡改定位功能和可靠的安全性.     

Incidental learning of S-R contingencies in the masked prime task.

Subliminal motor priming effects in the masked prime paradigm can only be obtained when primes are part of the task set. In 2 experiments, the authors investigated whether the relevant task set feature needs to be explicitly instructed or could be extracted automatically in an incidental learning paradigm. Primes and targets were symmetrical arrows, with target color, not shape, the response-relevant feature. Shape and color covaried for targets (e.g., always blue, >     

基于群签名的安全电子拍卖方案

针对双线性映射的群签名方案问题,为提高拍卖效率及安全性,提出了一个新的基于群签名的安全电子拍卖方案。以双线性映射为工具,引入矢量空间秘密共享技术和阈下通道技术。采用矢量空间秘密共享机制保证投标者对所投价位的匿名性;通过阈下通道实现确认中标者的打开过程。分析表明方案在相同安全性的要求下,签名的公钥长度是独立的,且签名长度较短,适合于分布式大规模的网上拍卖,实验证明是一个安全有效的电子拍卖方案。     

Illness schema activation and attentional bias to coping procedures.

Objective: Relatively little research to date has directly addressed the schematic nature of illness representations proposed by H. Leventhal, J. Weinman, and L. A. Phillips' (1980) common sense model of illness. The present experiments tested the hypothesis that coping information is schematically encoded within the representations of a specific illness. Design: A 2 (primed vs. control) × 2 (past user of coping strategy vs. nonuser of coping strategy) design was used in 2 experiments with independent samples. A subliminal prime was used to activate a common cold schema outside of conscious awareness. Main Outcome Measures: Response latencies in milliseconds for correct responses to a target common cold remedy word on a grammatical decision task served as the dependent measure in each experiment. Target words were Lemsip in Experiment 1 and lozenge in Experiment 2. Results: In each experiment, a significant interaction of Prime × Past Strategy Use was obtained. Participants in whom the "common cold" schema was activated and who also reported high past strategy use demonstrated attentional bias to the name of a popular common cold remedy. Conclusion: Activation of a schematic representation of illness may automatically activate information related to coping procedures encoded in memory with the illness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

存在潜信道的数字签名算法研究

潜信道是在公开信道中所建立的一种实现隐蔽通信的信道。介绍了潜信道方面的基本知识,提出了存在宽带潜信道和窄带潜信道的数字签名算法,并对这两种算法的安全性作了分析。