Stories and Cases: Discernment and Inference in Moral Deliberation

Theoretical Medicine and Bioethics -     

Parsing silhouettes: The short-cut rule

Many researchers have proposed that, for the purpose of recognition, human vision parses shapes into component parts. Precisely how is not yet known. The minima rule for silhouettes (Hoffman & Richards, 1984) defines boundary points at which to parse but does not tell how to use these points to cut silhouettes and, therefore, does not tell what the parts are. In this paper, we propose the short-cut rule, which states that, other things being equal, human vision prefers to use the shortest possible cuts to parse silhouettes. We motivate this rule, and the well-known Petter’s rule for modal completion, by the principle of transversality. We present five psychophysical experiments that test the short-cut rule, show that it successfully predicts part cuts that connect boundary points given by the minima rule, and show that it can also create new boundary points.     

Control of reflexive and voluntary saccades in the gap effect

In two experiments, we examined whether voluntary and reflexive saccades shared a common fixation disengagement mechanism, Participants were required to perform a variety of tasks, each requiring a different level of information processing of the display prior to execution of the saccade. In Experiment 1, participants executed either a prosaccade or an antisaccade upon detecting a stimulus array. In Experiment 2, participants executed a prosaccade to a stimulus array only if the array contained a target item. The target could be a line (easy search) or a digit (difficult search). The critical manipulation in both experiments was the relative timing between the removal of the fixation stimulus and the onset of the stimulus array. In both experiments, it was found that saccadic latencies were shortest when the fixation stimulus was removed before the onset of the stimulus array—a gap effect. It was concluded that reflexive and voluntary saccades share a common fixation disengagement mechanism that is largely independent of higher level cognitive processes.     

Induction with cross-classified categories

One of the main functions of categories is to allow inferences about new objects. However, most objects are cross-classified, and it is not known whether and how people combine information from these different categories in making inferences. In six experiments, food categories, which are strongly crossclassified (e.g., a bagel is both a bread and a breakfast food), were studied. For each food, the subjects were told fictitious facts (e.g., 75% of breads are subject to spoilage from Aspergillus molds) about two of the categories to which it belonged and then were asked to make an inference about the food (e.g., how likely is a bagel to be subject to spoilage from Aspergillus molds?). We found no more use of multiple categories in these cases of cross-classification than in ambiguous classification, in which it is uncertain to which category an item belongs. However, some procedural manipulations did markedly increase the use of both categories in inferences, primarily those that focused the subjects’ attention on the critical feature in both categories.     

One extreme or the other or perhaps the golden mean? Issues of spatial resolution in face processing

The findings of some of the key studies that have examined the contribution of different bands of spatial information, specified in terms of cycles per face, to face recognition, and identification are reviewed. Based on findings from studies of low-, high-, and band-pass filtering, it is concluded that neither low facial scales nor high facial scales are optimal. Instead, a center range of facial scales, approximately 8-16 cycles per face, appears to make the greatest contribution to the recognition process. A study of identification of band-pass filtered faces is reported that reinforces the view derived from the literature. This indicated that a band with a harmonic mean of 11.1 cycles per face provided the most efficient recognition, with speed and accuracy declining at lower and higher bands.     

A qualitative analysis of strategies for managing suicide-related events during deployment from the perspective of Army behavioral health providers,chaplains, and leaders

The purpose of this qualitative study was to investigate the use of strategies for managing suicide-related events (SREs; i.e., suicide deaths, suicide attempts, and suicidal ideation with a plan and intent to die) during deployment from the perspective of Army decision makers: behavioral health providers (BHPs), chaplains, and leaders. A total of 76 Army personnel participated in individual interviews or focus groups. Participants identified unit watch, weapon removal, medical evacuations, and debriefings as common strategies used to manage SREs in deployed settings. Many of these strategies were highlighted as short-term solutions only. Participants also underscored the importance of unit cohesion and communication among leaders, BHPs, and chaplains to effectively manage SREs. The need for structured guidelines for successfully managing SREs in deployed settings is discussed.     

The use of multiple reference points in risky decision making

Among psychologists and economists, prospect theory continues to be one of the most popular models of decision making. The theory's key property is reference dependence; specifically, how an individual's perception of loss or gain is dependent upon their starting point (i.e., the status quo). Although prospect theory is widely accepted, other authors have sought the inclusion of reference points besides the status quo. Initially these extensions focused on the importance of single reference points such as goals. More recently, authors have explained choice data by including multiple reference points within the value function. Multiple‐reference‐point theories generally assume that many choice situations possess an implicit or explicit goal, or point an individual will strive to obtain, and/or a minimum requirement (i.e., a “lower bound”) above which an individual will strive to stay. In two experiments, we present evidence that individuals can utilize the minimum requirement, status quo, and goal within a single risky decision task. Participants most often chose to maximize their chance of reaching reference points even when that decision was riskier, resulted in lower expected value, resulted in lower expected utility, or ran contrary to the predictions of prospect theory. Furthermore, salience and uncertainty moderated the use of goals and minimum requirements as reference points. Copyright © 2010 John Wiley & Sons, Ltd.