Articulation in the context of edge classification

Many researchers believe the human visual system classifies luminance edges into those produced by reflectance edges or those produced by illumination edges, yet this classification process is not completely understood. One suggestion is that heuristics are used for edge classification. For example. specific contrast relationships at the luminance edge ('codirectional contrast invariance' and 'transversal luminance-ratio preserving') may distinguish an illumination edge from a reflectance edge on the one hand, and from a translucent edge on the other. Distinct from luminance junctions, these features are global characteristics of the luminance pattern that make distinguishing between different types of edge easier with more highly articulated scenes. I demonstrate that apparent translucency, nonreversing X-junctions, and single-reversing X-junctions are insufficient on their own to produce the lightness illusion of Adelson's well-known tile pattern. While tolerating violations of the codirectional contrast invariance and transversal-luminance-ratio presersving without reversing the sign of contrast, the visual system is quite sensitive to such contrast reversal at the luminance edge. I account for this by suggesting that humans process lightness in terms of an ordinal, rather than interval, (or ratio) scale.     

Change in cognitive functioning associated with apoE genotype in a community sample of older adults

The influence of a genetic risk factor, apolipoprotein E (apoE) epsilon4 variant, was assessed in older adults aged 70 to 94 on 3 occasions over 7 years. The results of latent growth curve analyses are reported for individuals genotyped for apoE at the 2nd measurement occasion (n = 601) and for a subsample of individuals without probable or definite dementia during the 1st or 2nd occasion (n = 434). ApoE-epsilon4 status was a significant predictor of level and change in memory performance and change in speed performance in the full sample, and of initial level and change in memory performance in the nondemented subsample. These results support previous findings that apoE-epsilon4 is associated with accelerated memory deterioration in individuals without clinical dementia.     

Pain sensitivity and individual differences in self-reported sexual behavior

The relationship between sexual behavior and pain sensitivity was assessed in 27 heterosexual men and 20 heterosexual women. Sexual behavior measures included sexual motivation and ratings of subjective sexual arousal to and enjoyment of an auditory stimulus. Pain sensitivity measures were pain threshold and pain tolerance in a cold pressor task. Participants were tested after exposure to a neutral or a sexual audio stimulus. Exposure to the sexual stimulus increased pain sensitivity in women but not in men. However, sexual behavior measures were correlated with pain threshold for both men and women. Specifically, higher pain thresholds were associated with weaker sexual motivation, lower enjoyment potential for sexual interaction, and increased inhibition during intercourse. These results are consistent with findings in laboratory animals, suggesting that differences in sexual behavior may reflect differences in responsiveness to a variety of stimuli.     

Teamwork in multiteam systems

The authors examined how networks of teams integrate their efforts to succeed collectively. They proposed that integration processes used to align efforts among multiple teams are important predictors of multiteam performance. The authors used a multiteam system (MTS) simulation to assess how both cross-team and within-team processes relate to MTS performance over multiple performance episodes that differed in terms of required interdependence levels. They found that cross-team processes predicted MTS performance beyond that accounted for by within-team processes. Further, cross-team processes were more important for MTS effectiveness when there were high cross-team interdependence demands as compared with situations in which teams could work more independently. Results are discussed in terms of extending theory and applications from teams to multiteam systems.     

Straightness as a cue for luminance edge interpretation

In order to determine the reflectance of a surface, it is necessary to discount luminance changes produced by illumination variation, a process that requires the visual system to respond differently to luminance changes that are due to illumination and reflectance. It is known that various cues can be used in this process. By measuring the strength of lightness illusions, we find evidence that straightness is, used as a cue: When a boundary is straight rather than curved, it has a greater tendency to be discounted, as if it were an illumination edge. The strongest illusions occur when a boundary has high contrast and has multiple X-junctions that preserve a consistent contrast ratio.     

Eye movements and word skipping during reading revisited

The authors examined word skipping in reading in 2 experiments. In Experiment 1, skipping rates were higher for a preview of a predictable word than for a visually similar nonword, indicating there is full recognition in parafoveal vision. In Experiment 2, foveal load was manipulated by varying the frequency of the word preceding either a 3-letter target word or a misspelled preview. There was again a higher skipping rate for a correct preview and a lower skipping rate when there was a high foveal load, but there was no interaction, and the pattern of effects in fixation times was the same as in the skipping data. Experiment 2 also showed significant skipping of nonwords similar to the target word, indicating skipping based on partial information.     

Updating target location at the end of an orienting saccade affects the characteristics of simple point-to-point movements

Six results are reported. (a) Reaching accuracy increases when visual capture of the target is allowed (e.g., target on vs. target off at saccade onset). (b) Whatever the visual condition, trajectories diverge only after peak acceleration, suggesting that accuracy is improved through feedback mechanisms. (c) Feedback corrections are smoothly implemented, causing the corrected and uncorrected velocity profiles to exhibit similar shapes. (d) Initial kinematics poorly predict final accuracy whatever the condition, indicating that target capture is not the only critical input for feedback control. (e) Hand and eye final variability are unrelated, suggesting that gaze direction is not a target signal for arm control. (f) Extent errors are corrected without modification of movement straightness; direction errors cause path curvature to increase. Together these data show that movements with straight paths and bell-shaped velocity profiles are not necessarily ballistic.     

Putting stereotype content in context: image theory and interethnic stereotypes

Two studies apply intergroup image theory to better understand divergent interethnic images and to highlight the important role of intergroup context and perceived intergroup relations in shaping the content of social stereotypes. Image theory hypothesizes that specific interethnic stereotypes arise from specific patterns of perceived intergroup competition, relative power, and relative cultural status. Results from surveying Black, White, and Native Americans' appraisals of intergroup relations and reported outgroup stereotypes in various intergroup contexts suggest that the content of outgroup stereotypes varies systematically as a function of the perceived state of intergroup relations and the intergroup context in which these groups are situated. The data reported from both studies establish the importance of examining social stereotypes from a functional perspective in the context of intergroup relations.     

The effects of outcome expectations and satisfaction on weight loss and maintenance: correlational and experimental analyses--a randomized trial.

This study examines the hypothesis that highly favorable outcome expectations promote weight loss and hinder weight maintenance. To investigate the effects of outcome expectations and satisfaction with treatment outcomes on weight loss, 349 adults were randomly assigned to 1 of 2 weight loss programs that emphasize either (a) an "optimistic" message, focusing exclusively on the positive aspects of weight loss, or (b) a "balanced" message, giving equal time to positive and negative aspects of weight loss. Participants changed their weight loss cognitions in response to the intervention, but there was no significant difference between the intervention treatment groups in short-term or long-term (18-month) weight loss. Independent of treatment message, positive outcome expectations and satisfaction were both associated with weight loss.     

IQ decline following early unilateral brain injury: a longitudinal study

We examine whether children with early unilateral brain injury show an IQ decline over the course of development. Fifteen brain injured children were administered an IQ test once before age 7 and again several years later. Post-7 IQ scores were significantly lower than pre-7 IQ scores. In addition, pre-7 IQ scores were lower for children with larger lesions, but children with smaller lesions and higher pre-7 IQ scores showed a greater IQ decline over time. These findings suggest that the cognitive outcomes of children with early lesions, particularly those with relatively small lesions, change over the course of development.