Shifts in postdiscrimination gradients within a stimulus dimension based on bilateral facial symmetry

A shift in generalization gradients away from S+ and towards stimuli on the opposite end of the stimulus dimension from S- is a well established phenomenon in the laboratory, occurring with humans and nonhumans and with a wide range of stimuli. The phenomenon of gradient shifts has also been observed to have an analogous relationship to a variety of apparent biases in preference observed in the natural environment. One way to examine the validity of such analogies is by examining whether gradient shifts can be observed with complex and naturalistic stimuli. In the present experiment, undergraduates were trained to discriminate between faces that varied in terms of relative bilateral facial symmetry (a stimulus dimension correlated with health and attractiveness). Comparisons were made within subjects, using two sets of images. For both sets, the faces varied from naturally asymmetrical to symmetrical, and S+ was a face equidistant to the two extremes. With one set, S- was the naturally asymmetrical face, and with the other, S- was the symmetrical face. A peak shift was obtained in both conditions, although the effect was clearer in the aggregate than on the level of the individual. Overall, the results are consistent with the view that the processes responsible for gradient shifts in the lab are relevant to judgments made in the natural environment.     

网络旗帜广告的记忆效果

由于人们对网络旗帜广告效果的质疑,在网络广告的计费方式上也出现了两种计价模式,分别为按照浏览率和点击率来计量广告效果。其本质问题在于单纯浏览是否能够产生广告效果,以及浏览和点击各自所能带来的广告效果差异有多大。本研究利用模糊测量及相应统计方法,就上网者对网络旗帜广告的记忆效果进行测量。结果显示,在单纯浏览的情况下,上网者对网络旗帜广告已经留有印象,但这种记忆效果并不随着浏览次数的增加而显著改善;点击所能带来的广告记忆效果约为单纯浏览对应效果的1.4~1.5倍     

LEVEL OF INTERACTIVITY OF VIDEODISC INSTRUCTION ON COLLEGE STUDENTS' RECALL OF AIDS INFORMATION

Experiment 1 confirmed the greater effectiveness of constructed-response interactive videodisc instruction when compared to a click-to-continue or passive viewing formats on posttest recall of AIDS information by 101 college students. Experiment 2 extended the analysis using a counterbalanced (ABAB-BABA) intrasubject design with 4 students in each of three ability groups. The necessity of constructing answers appears to be an important factor in the effectiveness of instructional programs.     

Exposure to ozone inhibits isolation-induced aggressive behavior of adult CD-1 male mice

Continuous exposure to ozone (O₃, 1.2 ppm) in adult CD-1 male mice for 20 consecutive days markedly influenced a number of items of aggressive behavior induced by 59 days of individual housing. The behavior of mice was videotaped on days 1, 3, and 5 of five consecutive daily encounters (10 min each; isolation days 55, 57, and 59). Ozone exposure caused an abatement of aggressive behavior and enhanced fear-associated displays shown by a significant decrease in the frequency of attacking and digging and an increase in freezing. Moreover, O₃ induced a decrease of time spent in attacking and exploration/activity. Nonexposed animals exhibited a day-dependent increase in self-grooming frequency which was not observed in O₃ mice; by contrast, freezing was higher in O₃ mice on day 5 of the test. Data suggest that O₃ exposure produces a remarkable reduction of mouse aggression, indirectly confirming previous findings on physical and neurobehavioral effects of O₃. © 1995 Wiley-Liss, Inc.     

Evolution of communication in perfect and imperfect worlds

We extend previous work on cooperation to some related questions regarding the evolution of simple forms of communication. The evolution of cooperation within the iterated Prisoner's Dilemma has been shown to follow different patterns, with significantly different outcomes, depending on whether the features of the model are classically perfect or stochastically imperfect (Axelrod, 1980a,b, 1984, 1985; Axelrod and Hamilton, 1981; Nowak and Sigmund, 1990, 1992; Sigmund, 1993). Our results here show that the same holds for communication. Within a simple model, the evolution of communication seems to require a stochastically imperfect world.     

男性化与女性化对面孔偏好的影响—— 基于图像处理技术和眼动的检验

采用图像处理技术和眼动探讨了性别二态线索对面孔偏好的影响。实验1发现非面孔线索未掩蔽和掩蔽时, 感知男性化技术与原始照片条件下女性化的男性面孔更有吸引力和信任度; 性别二态技术条件下, 非面孔线索未掩蔽时男性化的男性面孔更有吸引力和信任度。实验2表明被试对男性面孔的平均瞳孔大小和注视次数均大于和多于女性面孔, 首次注视时间短于女性面孔; 被试对男性化面孔的首次注视时间和首次注视持续时间均长于女性化面孔。     

Learning in the brain–computer interface: insights about degrees of freedom and degeneracy from a landscape model of motor learning

In this paper, we examine the role of degrees of freedom and their degeneracy in learning in the brain–computer interface paradigm. Though the traditional notion of degrees of freedom in motor learning gave emphasis to muscle and joint activity, the broader concept of dimensions of behavior is relevant to brain–computer interface learning where there is no muscle activity. The role of degeneracy in the dimensions of brain activity is proposed to enhance learning through robustness to stability loss and adaptability in the search for new stable states. Principles for the application of augmented information for learning to coordinate and control the degenerate degrees of freedom in the brain–computer interface are outlined.