Peck tracking: a method for localizing critical features within complex pictures for pigeons

The pigeon is a standard animal in comparative psychology and is frequently used to investigate visuocognitive functions. Nonetheless, the strategies that pigeons use to discriminate complex visual stimuli remain a difficult area of study. In search of a reliable method to identify features that control the discrimination behaviour, pecking location was tracked using touch screen technology in a people-absent/people-present discrimination task. The correct stimuli contained human figures anywhere on the picture, but the birds were not required to peck on that part. However, the stimuli were designed in a way that only the human figures contained distinguishing information. All pigeons focused their pecks on a subarea of the distinctive human figures, namely the heads. Removal of the heads significantly impaired performance, while removal of other distinctive parts did not. Thus, peck tracking reveals the location within a complex visual stimulus that controls discrimination behaviour, and might be a valuable tool to reveal the strategies pigeons apply in visual discrimination tasks.     

Differentiating Type A behaviour and hyperactivity using observed motivation during a reaction time task

In light of the previously found overlap between Type A behaviour as measured by the Matthews Youth Test for Health (MYTH) and hyperactivity scales, the overall aim of this study was to clarify the standing of MYTH‐defined Type A behaviour relative to hyperactivity and Attention‐Deficit/Hyperactivity Disorder (ADHD), using observed task motivation and performance on a choice reaction‐time task, the Complex Reaction Time (CRT) measure. This study included 21 boys exhibiting Type A behaviour, 22 ADHD boys, 20 non‐clinically hyperactive boys, and 20 non‐hyperactive boys, between the ages of 6 and 13 years. It was proposed that a differentiation of constructs would be possible using observed task motivation if the MYTH were a discriminantly valid measure of Type A behaviour. Results showed that the MYTH‐defined Type A group differed from the clinically diagnosed ADHD group, although it was markedly similar to the non‐clinical hyperactive group, displaying comparable CRT performance and low level of task motivation. Type A behaviour correlated to CRT performance and task motivation in a way which was conceptually more indicative of hyperactivity than of Type A behaviour, which questions the validity of the MYTH as a measure of the Type A construct. The MYTH Impatience subscale was found to be particularly impure with regard to hyperactivity. Copyright © 2003 John Wiley & Sons, Ltd.     

White Racial Activism and Paper Terrorism: A Case Study in Far-Right Propaganda

ABSTRACT

In 2017, far-right mobilization and demonstrations in the United States were at the highest levels since the 1980s and 90s. This coincided with a marked increase in propaganda campaigns in neighborhoods and across college campuses. Racial activists renewed efforts to rebrand extreme positions, soften racist rhetoric, and grow the movement. The purpose of this case study was to explore the rhetorical content of the propaganda created by one white supremacist. This study contributes to a growing body of literature on far-right propaganda through an examination of common themes, and a comparison of the framing techniques and rhetorical strategies used by other white supremacists.     

Outline of a New Semantics for Counterfactuals

Abstract: It is argued that the so-called principles of "strong centering" and "weak centering" central to the traditional Lewis-Stalnaker semantics for counterfactuals are both fallacious. A foundation for an alternative semantics without these prinsciples is outlined. The core idea is that the statistically normal worlds – rather than those worlds most qualitatively similar to the actual world – should serve as the semantical fulcrum.     

In Defense of a Probability Based Semantics for Counterfactuals

In a recent paper Lee Walters criticizes a number of philosophers – including Gundersen – for committing a ‘failure in the argumentative strategy’ when they attempt to amend the standard Lewis semantics for counterfactuals in order to avoid the so‐called principle of Conjunction Conditionalization. In this article we defend a Gundersen‐style probability‐based semantics against Walter's major misgivings: that it is not logically conservative, that it is committed to the Connection Hypothesis, and that it cannot deal satisfactory with irrelevant semi‐factuals.