Perception of pictorial depth cues by pigeons

Pigeons were trained to discriminate pictures of intact objects from pictures of objects in which both depth from shading and depth from perspective cues were manipulated. Depth from shading was manipulated either by scrambling or by removing three-dimensional shading cues. Depth from perspective was manipulated either by presenting pictures of objects with a two-dimensional outline (i.e., a square) or with a three-dimensional outline (i.e., a cube). Transfer tests with novel images suggest that pigeons perceive and utilize both types of pictorial depth cues. The implications of these results for our understanding of picture perception in pigeons are discussed.     

Doctoral essays in computer ethics

Computer technologies are having a profoundly transforming effect on how the United States federal government operates. As technologies become more sophisticated, Federal agencies are becoming more innovative, devising creative ways to use these technologies for program delivery. One hopes that the near-term effect of these technology applications will be more efficient operation of government, the goal that generally leads to their implementation.     

Effect of varying the duration of grain presentation on automaintenance

In a series of three experiments the effects of variation in grain duration on automaintenance were evaluated. In the first experiment, key illumination was followed by grain only when pigeons did not peck the key. Each subject was exposed to 2-, 4-, and 8-second feeder durations in blocks of 10 sessions. Subjects pecked on a high percentage of trials at all feeder durations. The mean peck latency was shorter in the 8-second condition than in the two other conditions in five of six subjects. The conditional probability of pecking given successive keylight-grain pairings did not increase as the number of pairings increased. The second experiment was identical to the first, except that key pecking had no scheduled consequence. Under these conditions, all three subjects showed substantial responding. The recorded measures showed no systematic relationship to feeder duration in this study. In the third experiment, two different stimuli were followed by feeder presentations of either identical (2- or 8-second) or different (2- and 8-second) durations within each session. Subjects tended to respond sooner and with a higher overall rate in the presence of the stimulus associated with the longer feeder duration only when different feeder durations were presented within the same session. This result was confirmed by direct observation of the pigeons. The results of these experiments suggest that the effects of varying grain duration may be small, compared to the effects of varying other variables. The results also suggest that the location as well as the frequency of pecking may be an important measure in the analysis of factors controlling the pigeon's key peck.     

Effects of role model exposure on STEM and non‐STEM student engagement

Studies examining factors (e.g., STEM stereotypes) that underlie the recruitment and retention of STEM students are critical as the demand for STEM professionals is rapidly increasing. This experimental study tested the effects of role model biographies that challenge common STEM stereotypes (i.e., STEM is for gifted individuals and for European American males) on 1035 STEM and non‐STEM undergraduate students. Findings showed that role model exposure had positive effects on both STEM and non‐STEM students’ interest in STEM as well as their perceived identity compatibility between the self and STEM. Role model exposure had a positive impact on academic sense of belonging among STEM and non‐STEM students, and a positive impact on academic self‐efficacy among STEM students, but not non‐STEM students.     

BIS/BAS Levels and Psychiatric Disorder: An Epidemiological Study

Behavioral inhibition and behavioral activation levels have been theorized to relate to a broad range of psychopathologies. To date, however, studies have focused on a single diagnosis, and the measures used to assess different psychopathologies have varied greatly. This study assessed how levels of behavioral inhibition and behavioral activation relate to lifetime diagnoses of depression, anxiety, drug abuse and dependence, alcohol abuseand dependence, attention deficit hyperactivity disorder, and conduct disorder. A representative community sample of 1,803 individuals between the ages of 19 and 21 in the Miami area was surveyed with the Composite International Diagnostic Interview and the Behavioral Inhibition and Behavioral Activation Scales (BIS/BAS; C. S. Carver & T. White, 1994). Results supported the role of BIS as a vulnerability factor for depression and anxiety and of BAS Fun Seeking for drug abuse and noncomorbid alcohol diagnoses. Other models were not supported. Goals in understanding BIS and BAS are described, including the need for prospective studies with a broader array of behavioral indices.     

Qualitative Evaluation of Medical Information Processing Needs of 60 Women Choosing Ovarian Cancer Surveillance or Prophylactic Oophorectomy

Thirty women who had prophylactic oophorectomy (PO) and thirty women undergoing ovarian cancer surveillance (OCS) completed a one-time in-depth telephone interview exploring information gathering and decision-making processes. There were close similarities between groups, including age, race, marital status, education, menopausal status, number undergoing genetic testing for BRCA mutations, and number of prophylactic mastectomies. The majority of participants indicated overall satisfaction with their final decision. However, many described the information gathering process as frustrating and anxiety provoking. Participants in both groups expressed a need to process medical information within the context of individual psychosocial needs and personal perceptions and experiences. There were recurrent themes with regard to informational and psychosocial needs and personal perceptions and experiences that impacted decision-making process for these women. The present paper is a companion paper to Swisher et al. (J Repr Med 2001, 46:87–94) with the focus of this paper to illustrate the medical informational processing needs identified by this group of women.     

Restoring More than Smiles in Broken Homes: Dental and Oral Biomarkers of Brain Injury in Domestic Violence

ABSTRACT

While much of the focus on brain injury has centered on athletes and military veterans, victims of domestic violence (DV) comprise an under-represented cohort. Epidemiological studies show that a majority of domestic violence cases have a history of trauma to the head or neck resulting in both TBI and oral maxillofacial damage. However, distinctive oral injuries that are sustained simultaneously with brain trauma as a result of DV have yet to be fully elucidated. If a correlation can be made between specific oral injuries and TBI, then dentition may serve as a reliable biomarker for TBI. Specific dental biomarkers of injury would improve identification, diagnosis, and prognosis of TBI regardless of patient declamation. Dentists have the opportunity and obligation to add significantly to the body of knowledge regarding the frequency, presentation, profile, and characteristics of head and neck injuries of TBI in victims of DV. In so doing, the effort will fill the knowledge gaps and clarify misinformation in the lay, clinical, and scientific communities regarding the impact of TBI in DV events. The dental field can become a leader in branding the procedures, protocols, and clinical practices in the recognition and intervention against TBI in the DV population.     

Commonalities and differences in characteristics of persons at risk for narcissism and mania

Clinicians have long noted overlap in some of the key features of narcissism and bipolar disorder, including excessively high goals and impulsivity. In addition, empirical findings consistently document high levels of comorbidity between the two conditions. To better understand the similarities and differences in psychological qualities associated with mania- and narcissism-related vulnerabilities, we administered to 233 undergraduates a broad range of measures pertaining to goals and affects (both their experience and their dysregulation) and impulsivity. As hypothesized, tendencies toward both narcissism and hypomania related to elevations on measures of affective and goal dysregulation. In addition, hypomania tendencies were related to higher impulsivity, but that association did not appear for narcissistic tendencies. Results highlight key commonalities and differences between those at risk for mania versus narcissism. Future research should examine these relationships in clinically diagnosed samples.     

Memory influences on hippocampal and striatal neural codes: effects of a shift between task rules

Interactions with neocortical memory systems may facilitate flexible information processing by hippocampus. We sought direct evidence for such memory influences by recording hippocampal neural responses to a change in cognitive strategy. Well-trained rats switched (within a single recording session) between the use of place and response strategies to solve a plus maze task. Maze and extramaze environments were constant throughout testing. Place fields demonstrated (in-field) firing rate and location-based reorganization [Leutgeb, S., Leutgeb, J. K., Barnes, C. A., Moser, E. I., McNaughton, B. L., & Moser, M. B. (2005). Independent codes for spatial and episodic memory in hippocampal neuronal ensembles. Science, 309, 619-623] after a task switch, suggesting that hippocampus encoded each phase of testing as a different context, or episode. The task switch also resulted in qualitative and quantitative changes to discharge that were correlated with an animal's velocity or acceleration of movement. Thus, the effects of a strategy switch extended beyond the spatial domain, and the movement correlates were not passive reflections of the current behavioral state. To determine whether hippocampal neural responses were unique, striatal place and movement-correlated neurons were simultaneously recorded with hippocampal neurons. Striatal place and movement cells exhibited a response profile that was similar, but not identical, to that observed for hippocampus after a strategy switch. Thus, retrieval of a different memory led both neural systems to represent a different context. However, hippocampus may play a special (though not exclusive) role in flexible spatial processing since correlated firing amongst cell pairs was highest when rats successfully switched between two spatial tasks. Correlated firing by striatal cell pairs increased following any strategy switch, supporting the view that striatum codes change in reinforcement contingencies.     

Immediate early gene activation in hippocampus and dorsal striatum: effects of explicit place and response training

Evidence from lesion, electrophysiological, and neuroimaging studies support the hypothesis that the hippocampus and dorsal striatum process afferent inputs in such a way that each structure regulates expression of different behaviors in learning and memory. The present study sought to determine whether rats explicitly trained to perform one of two different learning strategies, spatial or response, would display disparate immediate early gene activation in hippocampus and striatum. c-Fos and Zif268 immunoreactivity (IR) was measured in both hippocampus and striatum 30 or 90 min following criterial performance on a standard plus-maze task (place learners) or a modified T-maze task (response learners). Place and response learning differentially affected c-Fos-IR in striatum but not hippocampus. Specifically, explicit response learning induced greater c-Fos-IR activation in two subregions of the dorsal striatum. This increased c-Fos-IR was dependent upon the number of trials performed prior to reaching behavioral criterion and accuracy of performance during post-testing probe trials. Quantification of Zif268-IR in both hippocampus and striatum failed to distinguish between place and response learners. The changes in c-Fos-IR occurred 30 min, but not 90 min, post-testing. The synthesis of c-Fos early in testing could reflect the recruitment of key structures in learning. Consequently, animals that were able to learn the response task efficiently displayed greater amounts of c-Fos-IR in dorsal striatum.