Detecting local convexity on the pareto surface

Recent regain in interest in multi‐criteria optimization approaches to provide a designer with multiple solutions to select from and support decisions has led to various methodologies to generate such solutions and possibly approximate the Pareto set. This paper introduces the notions of H‐ and w‐convexities, and develops a simple method to identify local convexity of Pareto hyper‐surfaces since their shape can dictate the choice of the method to use to obtain Pareto solutions and possibly to build an approximation of that set. The method is based on comparing the results from the weighting method to those of the Tchebycheff method at any point on the Pareto hyper‐surface. If, under some conditions, the points obtained from the two methods are identical or not, a local convexity or its lack can be assumed at that location and in its immediate neighbourhood. A numerical example is included. Copyright © 2002 John Wiley & Sons, Ltd.     

Saccadic eye movements and localization of visual stimuli

Visual localization phenomena were studied before, during, and after a saccade. Light flashes of 5 and 9 msec duration presented before and during the eye movement were mislocated in the saccade direction, the localization error being a time function. When the 9-msec duration stimulus and saccade did not overlap in time, a stripe was reported, when they did not, the stimulus was perceived as a point. If a long-duration stimulus moved perpendicularly to the saccade direction with the same “sigmoidal” velocity, a curvilinear trace was perceived, regardless of the linear trace of the image on the retina. A stimulus with stabilized retinal image was perceived as a stationary point during the saccade. A possible theory to deal with the data was suggested by modifying the algebra of outflow-inflow theories.     

I’m Not Feeling It: Momentary Experiential Avoidance and Social Anxiety Among Individuals With Social Anxiety Disorder

Previous studies have found that social anxiety and experiential avoidance (EA) are significantly associated, but the directionality of this relationship has not been firmly established. The present study examined momentary EA and social anxiety using repeated measurements during an opposite-sex interaction. Participants were 164 individuals (50% female): 42 were diagnosed with social anxiety disorder (SAD) and the remaining 122 were non-socially-anxious individuals (NSAs). Participants formed 42 experimental dyads including 1 individual with SAD and 1 NSA individual, and 40 control dyads including 2 NSA individuals. Lower-level mediational modeling indicated that for individuals with SAD, a reciprocal relationship was observed in which changes in both EA and social anxiety mediated changes in each other. However, changes in EA explained approximately 89% of changes in social anxiety whereas changes in social anxiety explained approximately 52% of changes in EA throughout the interaction. For NSA individuals, only social anxiety predicted EA. These findings point to a deleterious cycle driven mostly by EA among individuals with SAD, but not NSA individuals. Findings are discussed within the context of previous empirical findings as well as acceptance and commitment therapy (ACT) and cognitive-behavioral models of psychopathology.     

How extraverted is honey.bunny77@hotmail.de? Inferring personality from e-mail addresses

Computer mediated communication (CMC) plays a rapidly growing role in our social lives. Within this domain, e-mail addresses represent the thinnest slice of information that people receive from one another. Using 599 e-mail addresses of young adults, their self-reported personality scores and the personality judgments of 100 independent observers, it was shown that personality impressions based solely on e-mail addresses were consensually shared by observers. Moreover, these impressions contained some degree of validity. This was true for neuroticism, openness, agreeableness, conscientiousness, and narcissism but not for extraversion. Level of accuracy was explained using lens model analyses: Lay observers made broad use of perceivable e-mail address features in their personality judgments, features were slightly valid and observers were sensitive to subtle differences in validity between cues. Altogether, even the thinnest slice of CMC—the mere e-mail address—contains valid information about the personality of its owner.     

Selective attention is a primary determinant of the relationship between working memory and general learning ability in outbred mice

A single factor (i.e., general intelligence) can account for much of an individuals' performance across a wide variety of cognitive tests. However, despite this factor's robustness, the underlying process is still a matter of debate. To address this question, we developed a novel battery of learning tasks to assess the general learning abilities (GLAs) of mice. Using this battery, we previously reported a strong relationship between GLA and a task designed to tax working memory capacity (i.e., resistance to competing demands). Here we further explored this relationship by investigating which aspects of working memory (storage or processing) best predict GLAs in mice. We found that a component of working memory, selective attention, correlated with GLA comparably to working memory capacity. However, this relationship was not found for two other components of working memory, short-term memory capacity and duration. These results provide further evidence that variations in aspects of working memory and executive functions covary with general cognitive abilities.     

The relationship between covert and overt attention in endogenous cuing

In a standard Posner paradigm, participants were endogenously cued to attend to a peripheral location in visual space without making eye movements. They responded faster to target letters presented at cued than at uncued locations. On some trials, instead of a manual response, they had to move their eyes to a location in space. Results showed that the eyes deviated away from the validly cued location; when the cue was invalid and attention had to be allocated to the uncued location, eye movements also deviated away, but now from the uncued location. The extent to which the eyes deviated from cued and uncued locations was related to the dynamics of attention allocation. We hypothesized that this deviation was due to the successful inhibition of the attended location. The results imply that the oculomotor system is not only involved during the endogenous direction of covert attention to a cued location, but also when covert attention is directed to an uncued location. It appears that the oculomotor system is activated wherever spatial attention is allocated. The strength of saccade deviation might turn out to be an important measure for the amount of attention allocated to any particular location over time.