Does face recognition rely on encoding of 3-D surface? Examining the role of shape-from-shading and shape-from-stereo

It is now well known that processing of shading information in face recognition is susceptible to bottom lighting and contrast reversal, an effect that may be due to a disruption of 3-D shape processing. The question then is whether the disruption can be rectified by other sources of 3-D information, such as shape-from-stereo. We examined this issue by comparing identification performance either with or without stereo information using top-lit and bottom-lit face stimuli in both photographic positive and negative conditions. The results show that none of the shading effects was reduced by the presence of stereo information. This finding supports the notion that shape-from-shading overrides shape-from-stereo in face perception. Although shape-from-stereo did produce some signs of facilitation for face identification, this effect was negligible. Together, our results support the view that 3-D shape processing plays only a minor role in face recognition. Our data are best accounted for by a weighted function of 2-D processing of shading pattern and 3-D processing of shapes, with a much greater weight assigned to 2-D pattern processing.     

How We Teach Introductory Bible Courses: A Comparative and Historical Sampling

This study identifies the dominant modes of biblical interpretation being taught in introductory Bible courses through a qualitative analysis of course syllabi from three institutional contexts: evangelical Christian colleges, private colleges, and public universities. Despite a proliferation of methods and scholarly approaches to the Bible, this study reveals that historical‐critical approaches continue to predominate in pedagogical contexts, especially private colleges and public universities. In Christian colleges, theological approaches appear more frequently, usually alongside historical criticism and rarely supplanting it. The study also shows that teachers have been deploying social scientific and ideological approaches with increasing frequency over the past decade. Additionally, the study tracked instruments of student assessment in these courses. Public universities showed a particularly high level of pedagogical conservatism in this regard, while Christian colleges exhibit the greatest diversity with respect to course assignments and evaluations. See also “ Response to ‘How We Teach Introductory Bible Courses’ ” by Caryn A. Reeder, Tat‐siong Benny Liew, Jane S. Webster, Alicia J. Batten, and Chris Frilingos, published in this issue of the journal. The complete data set is included in an extended Appendix at the end of the article, and is also available electronically on the “Supporting Information” tab of the article's webpage and at the Wabash Center ( http://www.wabashcenter.wabash.edu/pdfs/AppendixCornellandLeMon.pdf ).     

The curse of knowledge: first language knowledge impairs adult learners' use of novel statistics for word segmentation

We investigated whether adult learners' knowledge of phonotactic restrictions on word forms from their first language impacts their ability to use statistical information to segment words in a novel language. Adults were exposed to a speech stream where English phonotactics and phoneme co-occurrence information conflicted. A control where these did not conflict was also run. Participants chose between words defined by novel statistics and words that are phonotactically possible in English, but had much lower phoneme contingencies. Control participants selected words defined by statistics while experimental participants did not. This result held up with increases in exposure and when segmentation was aided by telling participants a word prior to exposure. It was not the case that participants simply preferred English-sounding words, however, when the stimuli contained very short pauses, participants were able to learn the novel words despite the fact that they violated English phonotactics. Results suggest that prior linguistic knowledge can interfere with learners' abilities to segment words from running speech using purely statistical cues at initial exposure.     

Familiarity and retrieval processes in delayed judgments of learning

Two processes are postulated to underlie delayed judgments of learning (JOLs)--cue familiarity and target retrievability. The two processes are distinguishable because the familiarity-based judgments are thought to be faster than the retrieval-based processes, because only retrieval-based JOLs should enhance the relative accuracy of the correlations between the JOLs and criterion test performance, and because only retrieval-based judgments should enhance memory. To test these predictions, in three experiments, the authors either speeded people's JOLs or allowed them to be unspeeded. The relative accuracy of the JOLs in predicting performance on the criterion test was higher for the unspeeded JOLs than for the speeded JOLs, as predicted. The unspeeded JOL conditions showed enhanced memory as compared with the speeded JOL conditions, as predicted. Finally, the unspeeded JOLs were sensitive to manipulations that modified recallability of the target, whereas the speeded JOLs were selectively sensitive to experimental variations in the familiarity of the cues. Thus, all three of the predictions about the consequences of the two processes potentially underlying delayed JOLs were borne out. A model of the processes underlying delayed JOLs based on these and earlier results is presented.     

Evidence that judgments of learning are causally related to study choice

Three experiments investigated whether study choice was directly related to judgments of learning (JOLs) by examining people’s choices in cases in which JOLs were dissociated from recall. In Experiment 1, items were given either three repetitions or one repetition on Trial 1. Items given three repetitions received one on Trial 2, and those given one repetition received three on Trial 2—equating performance at the end of Trial 2, but yielding different immediate Trial 2 JOLs. Study choice followed the “illusory” JOLs. A delayed JOL condition in Experiment 2 did not show this JOL bias and neither did study choice. Finally, using a paradigm (Koriat & Bjork, 2005) in which similar JOLs are given to forward and backward associative pairs, despite much worse performance on the backward pairs, study choice again followed the mistaken JOLs. We concluded that JOLs—what people believe they know—directly influence people’s study choices.     

Acute predator stress impairs the consolidation and retrieval of hippocampus-dependent memory in male and female rats

We have studied the effects of an acute predator stress experience on spatial learning and memory in adult male and female Sprague-Dawley rats. All rats were trained to learn the location of a hidden escape platform in the radial-arm water maze (RAWM), a hippocampus-dependent spatial memory task. In the control (non-stress) condition, female rats were superior to the males in the accuracy and consistency of their spatial memory performance tested over multiple days of training. In the stress condition, rats were exposed to the cat for 30 min immediately before or after learning, or before the 24-h memory test. Predator stress dramatically increased corticosterone levels in males and females, with females exhibiting greater baseline and stress-evoked responses than males. Despite these sex differences in the overall magnitudes of corticosterone levels, there were significant sex-independent correlations involving basal and stress-evoked corticosterone levels, and memory performance. Most importantly, predator stress impaired short-term memory, as well as processes involved in memory consolidation and retrieval, in male and female rats. Overall, we have found that an intense, ethologically relevant stressor produced a largely equivalent impairment of memory in male and female rats, and sex-independent corticosterone-memory correlations. These findings may provide insight into commonalities in how traumatic stress affects the brain and memory in men and women.     

School Violence and the Culture of Honor

ABSTRACT— We investigated the hypothesis that a sociocultural variable known as the culture of honor would be uniquely predictive of school-violence indicators. Controlling for demographic characteristics associated in previous studies with violent crime among adults, we found that high-school students in culture-of-honor states were significantly more likely than high-school students in non-culture-of-honor states to report having brought a weapon to school in the past month. Using data aggregated over a 20-year period, we also found that culture-of-honor states had more than twice as many school shootings per capita as non-culture-of-honor states. The data revealed important differences between school violence and general patterns of homicide and are consistent with the view that many acts of school violence reflect retaliatory aggression springing from intensely experienced social-identity threats.     

Misunderstanding the affective consequences of everyday social interactions: the hidden benefits of putting one's best face forward

Positive self-presentation may have beneficial consequences for mood that are typically overlooked. Across a series of studies, participants underestimated how good they would feel in situations that required them to put their best face forward. In Studies 1 and 2A, participants underestimated the emotional benefits of interacting with an opposite sex stranger versus the benefits of interacting with a romantic partner. In Study 2B, participants who were instructed to engage in self-presentation felt happier after interacting with their romantic partner than participants who were not given this instruction, although other participants serving as forecasters did not anticipate such benefits. Increasing the generalizability of this self-presentation effect across contexts, the authors demonstrated that participants also underestimated how good they would feel before and after being evaluated by another person (Studies 3 and 4). This failure to recognize the affective benefits of putting one's best face forward may underlie forecasting errors regarding the emotional consequences of the most common forms of social interactions.     

The effects of acute plasma tryptophan manipulation on hostile mood: The influence of trait hostility

The effects of acute plasma tryptophan manipulation on changes in hostile, anxious, and depressive mood were studied in 48 males. Subjects consumed tryptophan-free or nutritionally balanced amino acid mixtures as a means of manipulating brain serotonin levels. Mood (hostility, anxiety, depression) was assessed pre- and 5 hr post-ingestion using the Multiple Affect Adjective Checklist. Overall, the tryptophan manipulation resulted in significant changes in hostile mood. Analyses also revealed a stronger association between changes in plasma tryptophan and changes in hostility in subjects with high levels of pre-existing hostile traits compared with low levels of hostile traits, and in subjects with high vs. Low antisocial traits. There was no significant association between changes in plasma tryptophan and changes in depression. The results suggest that persons with high levels of trait hostility may be more susceptible to the effects of acute manipulation of plasma tryptophan on hostile mood. Aggr. Behav. 24:173–185, 1998. © 1998 Wiley-Liss, Inc.