Why are there eccentricity effects in visual search? Visual and attentional hypotheses

In standard visual search experiments, observers search for a target item among distracting items. The locations of target items are generally random within the display and ignored as a factor in data analysis. Previous work has shown that targets presented near fixation are, in fact, found more efficiently than are targets presented at more peripheral locations. This paper proposes that the primary cause of this “eccentricity effect” (Carrasco, Evert, Chang, & Katz, 1995) is an attentional bias that allocates attention preferentially to central items. The first four experiments dealt with the possibility that visual, and not attentional, factors underlie the eccentricity effect. They showed that the eccentricity effect cannot be accounted for by the peripheral reduction in visual sensitivity, peripheral crowding, or cortical magnification. Experiment 5 tested the attention allocation model and also showed that RT X set size effects can be independent of eccentricity effects. Experiment 6 showed that the effective set size in a search task depends, in part, on the eccentricity of the target because observers search from fixation outward.     

Effects of Self-Monitoring on the On-Task Behavior and Written Language Performance of Elementary Students with Learning Disabilities

The present study was conducted to determine the effects of self-monitoring and a changing criterion with public posting phase on student on-task behavior and written language performance. Four elementary school boys participated and were enrolled in an urban-based, elementary-level resource room for students with learning disabilities. Self-monitoring procedures for on-task behavior included the students listening to a tone recorded at 60-s intervals and responding to the question, “Am I on-task?” Written language performance involved the students writing for a 10-min. session and counting and graphing the number of words written. During baseline conditions, student on-task behavior and written language performance were collected. During the self-monitoring conditions, the students monitored their on-task behavior and written language performance simultaneously. In the changing criterion with public posting condition, the students received their goal for the day's session prior to writing, wrote, and recorded whether they met their goal. While the results show a functional relationship between self-monitoring and on-task behavior, the data for the relationship between self-monitoring and written language performance were less compelling. A greater increase occurred when the changing criterion with public posting condition was introduced. Results suggest that self-monitoring changed on-task behavior; however, further research needs to be conducted to determine the conditions that would produce comparable effects for written language performance. Several implications for students and teachers and parent training were discussed.     

Vital anti-mathematicism and the ontology of the emerging life sciences: from Mandeville to Diderot

Synthese - Intellectual history still quite commonly distinguishes between the episode we know as the Scientific Revolution, and its successor era, the Enlightenment, in terms of the calculatory...     

Explaining Jury Verdicts: Is Leniency Bias for Real?

Laboratory research suggests juries that begin deliberation with a strong majority (i.e., 2/3 or more) usually end up choosing the verdict favored by this majority, whereas those without a strong majority generally acquit or hang. We tested the robustness of these findings in the field by examining trial and deliberation correlates of jury verdicts using data from 79 criminal jury trials held in Indiana. As expected, several trial characteristics and the first-vote preference distribution were related to jury verdicts. However, there was no evidence of leniency bias—75% of those juries without a 2/3 majority on the first deliberation vote ended up convicting. Contributions of the study, limitations, and alternative explanations for the observed severity bias are discussed.     

The effects of local prevalence and explicit expectations on search termination times

In visual search tasks, the relative proportions of target-present and -absent trials have important effects on behavior. Miss error rates rise as target prevalence decreases (Wolfe, Horowitz, & Kenner, Nature 435, 439-440, 2005). At the same time, search termination times on target-absent trials become shorter (Wolfe & Van Wert, Current Biology 20, 121-124, 2010). These effects must depend on some implicit or explicit knowledge of the current prevalence. What is the nature of that knowledge? In Experiment 1, we conducted visual search tasks at three levels of prevalence (6%, 50%, and 94%) and analyzed performance as a function of "local prevalence," the prevalence over the last n trials. The results replicated the usual effects of overall prevalence but revealed only weak or absent effects of local prevalence. In Experiment 2, the overall prevalence in a block of trials was 20%, 50%, or 80%. However, a 100%-valid cue informed observers of the prevalence on the next trial. These explicit cues had a modest effect on target-absent RTs, but explicit expectation could not explain the full prevalence effect. We conclude that observers predict prevalence on the basis of an assessment of a relatively long prior history. Each trial contributes a small amount to that assessment, and this can be modulated but not overruled by explicit instruction.     

Diversity and General Student Scholarship Recipient Essays: 2010 National Society of Genetic Counselors Membership Committee

In an effort to increase the diversity of the membership of the National Society of Genetic Counselors (NSGC), the Membership Committee provided two $500 scholarships to genetic counseling students planning to attend the NSGC AEC meeting in Dallas, Texas in October 2010. Requirements for applicants of both scholarships included enrollment in the fall of 2010, good standing at an accredited genetic counseling training program, and NSGC membership or plans to join in 2011. Students who are from communities underrepresented in the NSGC, including, but not limited to, those of minority cultural/ethnic backgrounds and those with disabilities were eligible to apply for the “Diversity” scholarship. Students from all backgrounds who have an interest in diversity issues were eligible to apply for the “General” scholarship. Applicants wrote essays 1000 words or less answering the following questions: How has your identity as a member of a group underrepresented in the genetic counseling profession affected your pursuit of this career? What do you feel is lacking in genetic counseling to address the issues of underrepresented groups? What strategies do you recommend for addressing these issues and/or increasing diversity? Why do you think diversity is an important issue for the field of genetic counseling? What strategies do you recommend to attract and retain students, especially those from underrepresented populations, into the field of genetic counseling? How do you envision contributing to these strategies? The essays by the award recipients elucidated interesting perspectives and ideas for increasing diversity in the genetic counseling profession.