Competing Explanations and Explaining-Away Arguments

An “explaining-away argument” [EAA] aims to discredit some explanatory hypothesis by appealing to the explanatory power of an alternative hypothesis. Nietzsche's genealogical argument against theism and Darwin's case against Paley's “old argument of design in nature” are famous examples. In order for EAAs to have their negative force, they must satisfy several conditions. After clarifying these conditions, I focus in on one in particular: the two hypotheses in question offer potential explanations that compete with one another. I develop a formal account of what it takes for potential explanations to compete, and I use this account to argue that EAAs are often misapplied today. This is due to the fact that philosophers often fail to appreciate the subtle line dividing competing from non-competing explanations.     

Reasoning about negligibility and proximity in the set of all hyperreals

We consider the binary relations of negligibility, comparability and proximity in the set of all hyperreals. Associating with negligibility, comparability and proximity the binary predicates N, C and P and the connectives $[N]$, $[C]$ and $[P]$, we consider a first-order theory based on these predicates and a modal logic based on these connectives. We investigate the axiomatization/completeness and the decidability/complexity of this first-order theory and this modal logic.     

策略转换的成本与顺序效应

灵活的策略转换是个体有效地解决问题的重要条件。策略转换需要成本已得到大量证明,但策略转换成本是否为对称转换成本尚无定论。基于已有研究,对策略转换中存在策略顺序困难效应与较差策略顺序调节效应两种典型的顺序效应进行了具体介绍。在此基础上提出了不对称策略转换成本可能是对称转换成本与策略顺序困难效应之和的假设,并进而提出设想:可通过操纵时间变量来分离策略顺序困难效应与较差策略顺序调节效应。此外,从策略转换成本的角度创新地阐释了策略选择的惰性与倒退现象。     

‘Language of the past’ – Exploring past tense disruption during autobiographical narration in neurodegenerative disorders

Compromised retrieval of autobiographical memory (ABM) is well established in neurodegenerative disorders. The recounting of autobiographical events is inextricably linked to linguistic knowledge, yet no study to date has investigated whether tense use during autobiographical narration is disrupted in dementia syndromes. This study investigated the incidence of correct past tense use during ABM narration in patients with Alzheimer's disease (AD, n = 10) and semantic dementia (SD, n = 10) in comparison with healthy older Controls (n = 10). Autobiographical narratives were analysed for episodic content (internal/external) and classified according to tense use (past/present). Across both patient groups, use of the past tense was significantly compromised relative to Controls, with increased levels of off‐target present tense verbs observed. Voxel‐based morphometry analyses based on structural MRI revealed differential associations between past tense use and regions of grey matter intensity in the brain. Bilateral temporal cortices were implicated in the SD group, whereas frontal, lateral, and medial temporal regions including the right hippocampus emerged in AD. This preliminary study provides the first demonstration of the disruption of specific linguistic constructs during autobiographical narration in AD and SD. Future studies are warranted to clarify at what point in the disease trajectory such deficits in tense use emerge, and whether these deficits are a product or contributing factor in memory disruption in these syndromes.     

A new variable interval schedule with constant hazard rate and finite time range

We propose a new variable interval (VI) schedule that achieves constant probability of reinforcement in time while using a bounded range of intervals. By sampling each trial duration from a uniform distribution ranging from 0 to 2 T seconds, and then applying a reinforcement rule that depends linearly on trial duration, the schedule alternates reinforced and unreinforced trials, each less than 2 T seconds, while preserving a constant hazard function.     

Failure to Replicate the Increased Temporal Resolution Induced by Images That Give Impression of Danger

Kobayashi and Ichikawa (2016) recently reported that briefly presented images with dangerous impressions were detected with higher accuracy than images with safe impressions and concluded that the emotion evoked by such images improves temporal resolution of visual perception. In this study, we assessed confounding effects of the color saturations of the images used in their study. While attempting to replicate their results, we found the opposite results—that is, images with safe impressions were detected with higher accuracy than those with dangerous impressions. This likely reflected an observed correlation between color saturations and detection thresholds. To confirm the effects of color saturations, in subsequent experiments, we independently examined the effects of emotion and of color characteristics. We concluded that the previously reported increased temporal resolution was due to the confounding effect of color saturation, and not by the evoked emotion.     

Learning from people, things, and signs

Starting from the observation that small children can count more objects than numbers—a phenomenon that I am calling the “lifeworld dependency of cognition”—and an analysis of finger calculation, the paper shows how learning can be explained as the development of cognitive systems. Parts of those systems are not only an individual’s different forms of knowledge and cognitive abilities, but also other people, things, and signs. The paper argues that cognitive systems are first of all semiotic systems since they are dependent on signs and representations as mediators. The two main questions discussed here are how the external world constrains and promotes the development of cognitive abilities, and how we can move from cognitive abilities that are necessarily connected with concrete situations to abstract knowledge.

The Aggregated Consequences of Motivated Reasoning and the Dynamics of Partisan Presidential Approval

Research in political psychology has shown the importance of motivated reasoning as a prism through which individuals view the political world. From this we develop the hypothesis that, with strong positive beliefs firmly in place, partisan groups ignore or discount information about the performance of political figures they like. We then speculate about how this tendency should manifest itself in presidential approval ratings and test our hypotheses using monthly presidential approval data disaggregated by party identification for the 1955–2005 period. Our results show that partisan groups generally do reward and punish presidents for economic performance, but only those presidents of the opposite party. We also develop a model of presidential approval for self-identified Independents and, finally, a model of the partisan gap , the difference in approval between Democrat and Republican identifiers.     

Adaptive non-interventional heuristics for covariation detection in causal induction: model comparison and rational analysis

In this article, 41 models of covariation detection from 2 × 2 contingency tables were evaluated against past data in the literature and against data from new experiments. A new model was also included based on a limiting case of the normative phi-coefficient under an extreme rarity assumption, which has been shown to be an important factor in covariation detection (McKenzie & Mikkelsen, 2007) and data selection (Hattori, 2002; Oaksford & Chater, 1994, 2003). The results were supportive of the new model. To investigate its explanatory adequacy, a rational analysis using two computer simulations was conducted. These simulations revealed the environmental conditions and the memory restrictions under which the new model best approximates the normative model of covariation detection in these tasks. They thus demonstrated the adaptive rationality of the new model.     

8 OOO名河北青少年预防艾滋病基本知识掌握情况调查与分析

对8000名河北青少年进行问卷调查,表明大部分青少年对艾滋病的传播途径、预防等知识有所了解,也有一定数量的青少年对艾滋病基本知识的了解不够全面和准确.今后的艾滋病预防宣传教育需要在广度、深度上加强,注重知识性、影响性和实效性,在宣传教育上注重社会、学校、家庭教育的结合.