Hope as a Predictor of Interpersonal Suicide Risk

The current study hypothesized that (1) hope would negatively predict burdensomeness, thwarted belongingness, and acquired capability to enact lethal injury; (2) hope would negatively predict suicidal ideation; and (3) the interpersonal suicide risk factors would predict suicidal ideation. Results indicated that hope negatively predicted burdensomeness and thwarted belongingness, but positively predicted acquired capability to enact suicide. Contrary to our second hypothesis, hope did not predict suicidal ideation, but interpersonal risk factors for suicide predicted suicidal ideation. Results are discussed in terms of implications for hope theory and Joiner's (2005) interpersonal risk factors for suicide, and for clinical practice.     

Recognizing faces defined by texture gradients

Texture gradients can reveal surface orientation in a manner similar to shape from shading, and therefore provide an important cue for object recognition. In this study, we tested whether a complex 3-D object, such as a face, can be identified from texture gradients alone. The stimuli were laser-scanned faces for which the texture element was a fractal-noise pattern mapped onto the 3-D surface. An eight-alternative forced choice task was used in which participants matched a face defined by texture gradients to one of eight faces defined by shape from shading (Experiment 1) or by texture gradients (Experiment 2). On average, participants scored 24% and 18%, respectively, above chance in these experiments. Although this performance was much poorer than the performance based entirely on shape-from-shading stimuli (Experiment 3), the results suggest that texture gradient information may be used to recover surface geometry of complex objects.     

Don't tread on me: masculine honor ideology in the U.S. and militant responses to terrorism

Using both college students and a national sample of adults, the authors report evidence linking the ideology of masculine honor in the U.S. with militant responses to terrorism. In Study 1, individuals' honor ideology endorsement predicted, among other outcomes, open-ended hostile responses to a fictitious attack on the Statue of Liberty and support for the use of extreme counterterrorism measures (e.g., severe interrogations), controlling for right-wing authoritarianism, social dominance orientation, and other covariates. In Study 2, the authors used a regional classification to distinguish honor state respondents from nonhonor state respondents, as has traditionally been done in the literature, and showed that students attending a southwestern university desired the death of the terrorists responsible for 9/11 more than did their northern counterparts. These studies are the first to show that masculine honor ideology in the U.S. has implications for the intergroup phenomenon of people's responses to terrorism.     

The preference for symmetry in flower-naïve and not-so-naïve bumblebees

Truly flower-naïve bumblebees, with no prior rewarded experience for visits on any visual patterns outside the colony, were tested for their choice of bilaterally symmetric over asymmetric patterns in a radial-arm maze. No preference for symmetry was found. Prior training with rewarded black and white disks did, however, lead to a significant preference for symmetry. The preference was not specific to symmetry along the vertical axis: a preference for horizontal symmetry was found as well. The results challenge the notion that a preference for bilateral symmetry is unlearned. The preference for symmetry was the product of non-differential conditioning.     

Effects of image background on spatial-frequency thresholds for face recognition

A great deal of work has been devoted to the question of which spatial frequencies, if any, are optimal for various visual tasks, such as face and object recognition. However, to date these studies have all been carried out with stimuli set against a uniform background. It is possible that this type of stimulus does not produce ecologically valid results. The natural world in which visual tasks normally take place involves a great deal of luminance variation and distracting visual structure, which may alter the spatial frequencies necessary for a task. We conducted two experiments that examined the effects of image background on the spatial-frequency thresholds (50% maximum of a low-pass or high-pass Butterworth filter) for face recognition by the psychophysical methods of adjustment and constant stimuli. In both experiments we found no significant difference in spatial-frequency thresholds between uniform-grey backgrounds and natural-scene backgrounds, and only minor differences between uniform-grey backgrounds and fractal noise backgrounds. This suggests that results obtained with uniform backgrounds are ecologically valid and that background effects, if they exist, are small.     

Using MATLAB with the Psychophysics Toolbox to present the heterochromatic fusion nystagmus stimulus

We present a program for MATLAB that generates and presents theheterochromatic fusion nystagmus stimulus. This stimulus allows assessment of isoluminant states through recordings of reflexive eye movements (optokinetic nystagmus). The reflexive nature of the subject’s response makes this stimulus especially useful with nonverbal subjects, such as children and animals. Unfortunately, the stimulus is complex and difficult to program. By presenting the present program, we hope to help those who wish to use this tool in their research. The code of the function can be downloaded at www. dal.ca/~mcmullen/downloads.html.     

Spatial vision meets spatial cognition: examining the effect of visual blur on human visually guided route learning

Visual navigation is a task that involves processing two-dimensional light patterns on the retinas to obtain knowledge of how to move through a three-dimensional environment. Therefore, modifying the basic characteristics of the two-dimensional information provided to navigators should have important and informative effects on how they navigate. Despite this, few basic research studies have examined the effects of systematically modifying the available levels of spatial visual detail on navigation performance. In this study, we tested the effects of a range of visual blur levels--approximately equivalent to various degrees of low-pass spatial frequency filtering--on participants' visually guided route-learning performance using desktop virtual renderings of the Hebb-Williams mazes. Our findings show that the function of blur and time to finish the mazes follows a sigmoidal pattern, with the inflection point around +2 D of experienced defocus. This suggests that visually guided route learning is fairly robust to blur, with the threshold level being just above the limit for legal blindness. These findings have implications for models of route learning, as well as for practical situations in which humans must navigate under conditions of blur.     

Protection,payback, or both? Emotional and motivational mechanisms underlying avoidance by victims of transgressions

In the wake of an interpersonal offense, victims often feel motivated to avoid their perpetrators, and the more severe the offense, the more pronounced this motivation is. On the surface, avoidance appears to serve a self-protective function such that victims, compelled by a sense of fear and apprehension, withdraw from their wrongdoers to prevent further harm. However, avoidance might also serve a retaliatory purpose in which victims shun their offenders out of anger and hostility, using interpersonal aloofness as a means of payback. In the present pair of studies, we examined victims’ self-reports of recent offense experiences and tested the mediating roles of fear and anger in the relationship between offense severity and avoidance motivations. Study 1 revealed that anger, not fear, was the emotion that mediated this relationship. Study 2 replicated this finding and also showed that the link between anger and avoidance was mediated both by revenge and self-protection motives, which demonstrates the complex nature of avoidance following a transgression.