On Discriminating between Geometric Strategies of Surface-Based Orientation

Recently, a debate has manifested in the spatial learning literature regarding the shape parameters by which mobile organisms orient with respect to the environment. On one hand are principal-axis-based strategies which suggest that organisms extract the major and minor principal axes of space which pass through the centroid and approximate length and width of the entire space, respectively. On the other hand are medial-axis-based strategies which suggest that organisms extract a trunk-and-branch system similar to the skeleton of a shape. With competing explanations comes the necessity to devise experiments capable of producing divergent predictions. Here, we suggest that a recent experiment (i.e., Sturz and Bodily, 2011a) may be able to shed empirical light on this debate. Specifically, we suggest that a reevaluation of the design reveals that the enclosures used for training and testing appear to produce divergent predictions between these strategies. We suggest that the obtained data appear inconsistent with a medial-axis-based strategy and that the study may provide an example of the types of designs capable of discriminating between these geometric strategies of surface-based orientation. Such an approach appears critical to fundamental issues regarding the nature of space and spatial perception

Teaching Narrative Interviewing: Reflecting, Narrating, and Becoming-In-Action

Qualitative inquiry teachers often seek powerful pedagogies to improve their students’ understandings. Using our experience leading a doctoral workshop, we share our method for teaching narrative interviewing using Schön’s (1983) “reflection-in-action,” meaning teachers and students reflect in the moment. We also root our pedagogy in Jerome Bruner’s (1986, 1990) narrative as a mode of thinking and a mode of being, a philosophy exploring the ways learners story their own and others’ lives. Describing our doctoral workshop, we highlight Laura, a recent graduate, narrating and becoming a qualitative inquirer. We conclude with a sample teaching lesson, designed to enhance students’ reflective research practices

Evidence Consistent With the Multiple-Bearings Hypothesis From Human Virtual Landmark-Based Navigation

One approach to explaining the conditions under which additional landmarks will be learned or ignored relates to the nature of the information provided by the landmarks (i.e., distance versus bearings). In the current experiment, we tested the ability of such an approach to explain the search behavior of human participants in a virtual landmark-based navigation task by manipulating whether landmarks provided stable distance, stable direction, or both stable distance and stable direction information. First, we incrementally shaped human participants’ search behavior in the presence of two ambiguous landmarks. Next, participants experienced one additional landmark that disambiguated the location of the goal. Finally, we presented three additional landmarks. In a control condition, the additional landmarks maintained stable distances and bearings to the goal across trials. In a stable bearings condition, the additional landmarks varied in their distances but maintained fixed bearings to the goal across trials. In a stable distance condition, the additional landmarks varied in their bearings but maintained fixed distances to the goal across trials. Landmark stability, in particular, the stability of landmark-to-goal bearings, affected learning of the added landmarks. We interpret the results in the context of the theories of spatial learning that incorporate the nature of the information provided by landmarks

Do Eye Movements During Shape Discrimination Reveal an Underlying Geometric Structure?

Using a psychophysical approach coupled with eye-tracking measures, we varied length and width of shape stimuli to determine the objective parameters that corresponded to subjective determination of square/rectangle judgments. Participants viewed a two-dimensional shape stimulus and made a two-alternative forced-choice whether it was a square or rectangle. Participants’ gaze was tracked throughout the task to explore directed visual attention to the vertical and horizontal axes of space. Behavioral results provide threshold values for two-dimensional square/rectangle perception, and eye-tracking data indicated that participants directed attention to the major and minor principal axes. Results are consistent with the use of the major and minor principal axis of space for shape perception and may have theoretical and empirical implications for orientation via geometric cues

Computed tomographic enterography adds information to clinical management in small bowel Crohn's disease

Background: CT enterography yields striking findings in the bowel wall in Crohn's disease. These images may help to evaluate whether small bowel narrowing results from active disease requiring anti-inflammatory therapy. However, the clinical relevance of these images is unknown. It is also not known if these radiologic findings correlate with objective biomarkers of inflammation. Methods: In a blinded and independent evaluation, IBD subspecialty gastroenterologists reviewed clinical data, and CT radiologists reviewed CT enterography scans of 67 consecutive patients with Crohn's disease and suspicion of either small bowel inflammation or stricture. Comparisons were made between (1) clinical and radiologic assessments of inflammation and stricture, (2) clinical assessments before and after computed tomographic enterography (CTE) reports were revealed, and (3) radiologic findings and objective biomarkers of inflammation. Results: (1) Individual CTE findings correlated poorly (Spearman's rho < 0.30) with clinical assessment; (2) clinicians did not suspect 16% of radiologic strictures, and more than half the cases of clinically suspected strictures did not have them on CTE; (3) CTE data changed clinicians' perceptions of the likelihood of steroid benefit in 41 of 67 cases; (4) specific CTE findings correlated with CRP, and a distinct set of CTE findings correlated with ESR in the subset of patients who had these biomarkers measured. Conclusions: CTE seems to add unique information to clinical assessment, both in detecting additional strictures and in changing clinicians' perceptions of the likelihood of steroids benefiting patients. The biomarker correlations suggest that CTE is measuring real biologic phenomena that correlate with inflammation, providing information distinct from that in a standard clinical assessment. (Inflamm Bowel Dis 2006)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55965/1/20013_ftp.pd

Same/Different Concept Learning by Capuchin Monkeys in Matching-to-Sample Tasks

The ability to understand similarities and analogies is a fundamental aspect of human advanced cognition. Although subject of considerable research in comparative cognition, the extent to which nonhuman species are capable of analogical reasoning is still debated. This study examined the conditions under which tufted capuchin monkeys (Cebus apella) acquire a same/different concept in a matching-to-sample task on the basis of relational similarity among multi-item stimuli. We evaluated (i) the ability of five capuchin monkeys to learn the same/different concept on the basis of the number of items composing the stimuli and (ii) the ability to match novel stimuli after training with both several small stimulus sets and a large stimulus set. We found the first evidence of same/different relational matching-to-sample abilities in a New World monkey and demonstrated that the ability to match novel stimuli is within the capacity of this species. Therefore, analogical reasoning can emerge in monkeys under specific training conditions