Heavy drinking in college students: who is at risk and what is being done about it?

Problem drinking and related consequences are a major social issue plaguing college campuses across the United States. Each year, alcohol is responsible for fatalities, assaults, serious injuries, and arrests that occur among college students. The authors review and discuss the risk factors, drinking patterns, and consequences that are relevant to the general student population. In addition, the authors highlight individuals at an increased risk of experiencing alcohol-related problems, such as Greek-letter social organization members and student athletes. The authors also discuss the interventions that attempt to reduce risky drinking and related problems in these subgroups as well as the future directions for research.     

Object recognition in dense clutter

Observers in recognition experiments invariably view objects against a blank background, whereas observers of real scenes sometimes view objects against dense clutter. In this study, we examined whether an object's background affects the information used for recognition. Our stimuli consisted of color photographs of everyday objects. The photographs were organized either as a sparse array, as is typical of a visual search experiment, or as high density clutter, such as might be found in a toy chest, a handbag, or a kitchen drawer. The observer's task was to locate an animal, vehicle, or food target in the stimulus. We varied the information in the stimuli by convolving them with a low-pass filter (blur) or a high-pass filter (edge) or converting them to grayscale. In two experiments, we found that the blur and edge manipulations produced a modest decrement in performance with the sparse arrangement but a severe decrement in performance with the clutter arrangement. These results indicate that the information used for recognition depends on the object's background. Thus, models of recognition that have been developed for isolated objects may not generalize to objects in dense clutter.     

Tactile spatial acuity differs between fingers: a study comparing two testing paradigms

Tactile spatial acuity (TSA) is a reliable and reproducible measure of somatosensory system function that has been used to study abroad range of subject populations. Although TSA is most often assessed at the fingertip, published studies employing identical stimuli disagree on whether TSA differs between the fingers of neurologically normal subjects. Using a validated grating orientation discrimination task, we determined TSA bilaterally at the index and ring fingers of 16 healthy young adults. Motivated by earlier work, we utilized two stimulus presentation paradigms, the method of constant stimuli (MCS) and a staircase (SC) method. We found that TSA was significantly higher (the discrimination threshold was lower) at the index than at the ring finger, which was consistent with a prior study. Although mean thresholds at both fingers were higher when measured with the SC than with the MCS paradigm, this difference did not reach statistical significance (p = .14). These findings should facilitate both design and interpretation of future studies investigating TSA.     

Re-analysis of Sageman's (2004) and Pape's (2005) data predicting Al'Qaeda membership and suicide terrorism

Sageman's (2004) and Pape's (2005) arguments for the development of Al'Qaeda members and suicide terrorism are examined statistically. Presence of foreign occupying troops and foreign support for disliked local regimes appeared to be related to either the number of Al'Qaeda suicide terrorists (Pape) or the number of known Al'Qaeda members (Sageman) reported within 34 predominately Sunni nations. Results support the theory that nationalism fuels much of Middle Eastern resentment against allied nations.     

Cross-National Variations in Behavioral Profiles Among Homeless Youth

Cross-national comparisons of homeless youth in Melbourne, Australia, and Los Angeles, CA, United States were conducted. Newly (n = 427) and experienced (n = 864) homeless youth were recruited from each site. Compared to Australia, homeless youth in the United States were younger, more likely to be in school or jail, demonstrated fewer sexual and substance use risk acts, fewer suicidal acts, and reported less need for social services. Across sites, experienced homeless youth were more likely to be older, male, engage in sexual and substance use, report greater need for social services, and make greater use of work, substance use, and health-related services. Homeless youth have different behavioral profiles in Australia and the United States, reflecting differences in the effectiveness of service systems in the two countries in keeping youth with fewer problems out of homelessness.     

Developmental patterns in priming and familiarity in explicit recollection

Developmental trajectories of two classes of human memory, implicit and explicit memory, appear to diverge. We examined how developmental differences in perceptual and conceptual priming, two types of implicit memory, coincide with differences between familiarity and recollective responses on explicit memory tests that employ the Remember/Know paradigm ( Tulving, 1985 ). Both types of priming were characterized by developmental invariance in 52 children and adolescents ages 8-19 years. Contrary to Komatsu, Naito, and Fuke (1996) results, few age-group differences in perceptual priming were observed following a levels-of-processing encoding manipulation. In contrast, age group differences were found for "Remember" but not "Know" responses. Neither levels of awareness nor strategies influenced priming. Adult levels of performance appear earlier in development on perceptual and conceptual priming tests compared to explicit memory tests. Similar developmental dissociations exist between explicit and implicit memory performance as between "Remember" and "Know" recollective responses.