On the bias of Huffcutt and Arthur's (1995) procedure for identifying outliers in the meta-analysis of correlations

This study documents how the use of A. I. Huffcutt & W. A. Arthur's (1995) sample adjusted meta-analytic deviancy (SAMD) statistic for identifying outliers in correlational meta-analyses results in inaccuracies in mean r. Monte Carlo simulations found that use of the SAMD resulted in the overidentification of small relative to large correlations as outliers. Furthermore, this tendency to overidentify small correlations was found to increase as the magnitude of the population correlation increased and resulted in mean rs that overestimated the population correlation. The implications for meta-analysts are discussed, and 2 possible solutions are offered.     

On the generality of optimal versus objective classifier feedback effects on decision criterion learning in perceptual categorization

Biased category payoff matrices engender separate reward- and accuracy-maximizing decision criteria Although instructed to maximize reward, observers use suboptimal decision criteria that place greater emphasis on accuracy than is optimal. In this study, objective classifier feedback (the objectively correct response) was compared with optimal classifier feedback (the optimal classifier's response) at two levels of category discriminability when zero or negative costs accompanied incorrect responses for two payoff matrix multiplication factors. Performance was superior for optimal classifier feedback relative to objective classifier feedback for both zero- and negative-cost conditions, especially when category discriminability was low, but the magnitude of the optimal classifier advantage was approximately equal for zero- and negative-cost conditions. The optimal classifier feedback performance advantage did not interact with the payoff matrix multiplication factor. Model-based analyses suggested that the weight placed on accuracy was reduced for optimal classifier feedback relative to objective classifier feedback and for high category discriminability relative to low category discriminability. In addition, the weight placed on accuracy declined with training when feedback was based on the optimal classifier and remained relatively stable when feedback was based on the objective classifier. These results suggest that feedback based on the optimal classifier leads to superior decision criterion learning across a wide range of experimental conditions.     

Revisiting the Obama Effect: Exposure to Obama reduces implicit prejudice

The present research experimentally evaluated whether exposure to Barack Obama, a positive counter-stereotypic exemplar, can result in a decrease in implicit anti-Black prejudice among non-Black participants. In order to undo any existing influence of exposure to Obama, we first exposed some participants to negative Black exemplars. Participants were assigned to one of three conditions where they were exposed subtly to negative Black exemplars, to negative Black exemplars and then Obama, or to neutral X's (i.e., control). Participants who were only primed with negative Black exemplars showed more implicit negativity toward Black people compared to the control group. Participants exposed to the same negative Black exemplars and then Obama showed a decrease in implicit racial bias levels compared to those in the negative exemplar only condition, providing experimental evidence that exposure to Obama can decrease implicit racial bias levels. These findings indicate that even subtle exposure to a positive, counter-stereotypic exemplar can reduce implicit prejudice.     

Analog and digital,continuous and discrete

Representation is central to contemporary theories regarding the mind/brain. But the nature of representation—both in the mind/brain and more generally—is a source of ongoing controversy. One way of categorizing representational types is to distinguish between the analog and the digital: the received view is that analog representations vary smoothly, while digital representations vary in a step-wise manner. In other words, ‘digital’ is synonymous with ‘discrete’, while ‘analog’ is synonymous with ‘continuous’. I argue that this characterization is inadequate to account for the ways in which representation is (and should be) used in cognitive science; in its place, I suggest an alternative taxonomy. I will defend and extend David Lewis’s account of analog and digital representation, distinguishing analog from continuous representation, as well as digital from discrete representation. I will argue that the distinctions available in this fourfold account better accord with representational features of interest in cognitive science than the received analog/digital dichotomy.     

Contractualism,Person-Affecting Wrongness and the Non-identity Problem

A number of theorists have argued that Scanlon's contractualist theory both "gets around" and "solves" the non-identity problem. They argue that it gets around the problem because hypothetical deliberation on general moral principles excludes the considerations that lead to the problem. They argue that it solves the problem because violating a contractualist moral principle in one's treatment of another wrongs that particular other, grounding a person-affecting moral claim. In this paper, I agree with the first claim but note that all it shows is that the act is impersonally wrong. I then dispute the second claim. On Scanlon's contractualist view, one wrongs a particular other if one treats the other in a way that is unjustifiable to that other on reasons she could not reasonably reject. We should think of person-affecting wronging in terms of the reasons had by the actual agent and the actual person affected by the agent's action. In non-identity cases, interpersonal justifiability is therefore shaped both by the reason to reject the treatment provided by the bad suffered and the reason to affirm the treatment provided by the goods had as a result of existing. I argue it would be reasonable for the actual person to find the treatment justifiable, and so I conclude that Scanlon's contractualist metaethics does not provide a narrow person-affecting solution to the non-identity problem on its own terms. I conclude that the two claims represent a tension within Scanlon's contractualist theory itself.     

The Visual Spatial Learning Test: Differential impairment during the premanifest and manifest stages of Huntington's disease

Visual spatial memory was assessed using the Visual Spatial Learning Test (VSLT) in individuals with mild to moderate Huntington's disease (HD), pre‐manifest gene carriers for HD, and demographically similar controls. The VSLT has been demonstrated to be a valid, normed measure of non‐verbal memory involving minimal motoric responses. The VSLT assesses immediate and delayed memory for designs, positions of the designs, and design/position associations. The HD group was significantly impaired (p < .05) relative to both the control and Pre‐HD groups on immediate and delayed memory for the designs, positions, and design/position associations. Although there were no differences between the Pre‐HD and control groups on immediate or delayed memory for designs or positions, the Pre‐HD group was significantly impaired (p < .05) relative to the control group on immediate and delayed memory for design/position associations. The results offer novel insight into a relatively unexamined memory deficit that may occur in gene carriers for HD prior to phenoconversion. The data indicate that the VSLT may be a useful measure of visuospatial memory during the premanifest and manifest stages of HD.     

Quantifier comprehension in corticobasal degeneration

In this study, we investigated patients with focal neurodegenerative diseases to examine a formal linguistic distinction between classes of generalized quantifiers, like "some X" and "less than half of X." Our model of quantifier comprehension proposes that number knowledge is required to understand both first-order and higher-order quantifiers. The present results demonstrate that corticobasal degeneration (CBD) patients, who have number knowledge impairments but little evidence for a deficit understanding other aspects of language, are impaired in their comprehension of quantifiers relative to healthy seniors, Alzheimer's disease (AD) and frontotemporal dementia (FTD) patients [F(3,77)=4.98; p<.005]. Moreover, our model attempts to honor a distinction in complexity between classes of quantifiers such that working memory is required to comprehend higher-order quantifiers. Our results support this distinction by demonstrating that FTD and AD patients, who have working memory limitations, have greater difficulty understanding higher-order quantifiers relative to first-order quantifiers [F(1,77)=124.29; p<.001]. An important implication of these findings is that the meaning of generalized quantifiers appears to involve two dissociable components, number knowledge and working memory, which are supported by distinct brain regions.     

Relationship Quality as a Moderator of Anxiety in Siblings of Children Diagnosed with Autism Spectrum Disorders or Down Syndrome

The purpose of this study was to examine typically-developing adolescents’ perceived relationship quality with their developmentally-disabled sibling, specifically siblings diagnosed with an autism spectrum disorder (ASD) or Down syndrome (DS). The 119 eleven through seventeen-year-old adolescent participants (M = 13.32, SD = 1.90) completed an online survey that assessed demographics, sibling relationship quality, and anxiety. Results showed that siblings of children with DS have a greater overall sibling relationship quality than do siblings of children with an ASD. Results further indicated that reporting more negative interchanges within the sibling relationship was related to higher levels of anxiety regardless of sibling disability type. Lastly, sibling relationship quality moderated the relation between sibling disability type and anxiety. These findings promote greater understanding of the sibling dynamic in families with children with developmental disabilities and suggest the need for establishing more research and greater clinical evaluation in this area. Furthermore, the current study suggests that therapeutic intervention to address the sibling relationship quality within children diagnosed with ASDs and their typically-developing siblings would be beneficial in order to increase social support within the relationship as well as decrease the amount of negative interchanges within the sibling relationship. Results also suggested that decreasing the amount of negative interchanges within the sibling relationship may decrease the level of anxiety the typically-developing sibling reports.