Visual object affordances: object orientation

Five experiments systematically investigated whether orientation is a visual object property that affords action. The primary aim was to establish the existence of a pure physical affordance (PPA) of object orientation, independent of any semantic object-action associations or visually salient areas towards which visual attention might be biased. Taken together, the data from these experiments suggest that firstly PPAs of object orientation do exist, and secondly, the behavioural effects that reveal them are larger and more robust when the object appears to be graspable, and is oriented in depth (rather than just frontally) such that its leading edge appears to point outwards in space towards a particular hand of the viewer.     

The role of visual attention in action priming

It has been demonstrated that the task-irrelevant left-right orientation of an object is capable of facilitating left-right-hand responses when the object is orientated towards the responding hand. We investigated the role of attention in this orientation effect. Experiment 1 showed that object orientation facilitates responses of the hand that is compatible with the object's orientation, despite the entire object being irrelevant. However, when a task-relevant fixation point was displayed over the prime object in Experiment 2, the effect was not observed. Together Experiments 1 and 2 suggest that the orientation information of viewed objects primes the action selection processes even when the object is irrelevant, but only when attention is not allocated to a competing stimulus during the prime presentation. Experiment 3 suggested that the elimination of the effect in Experiment 2 could not be attributed to the elimination of an attentional shift to the graspable part of the prime. Finally, Experiment 4 showed that object orientation can evoke an abstract response code, influencing the selection of finger responses.     

Repeated Repetition Priming in Face Recognition

Prior exposure to an item can facilitate subsequent recognition of that item. This effect, known as repetition priming, has been found for the recognition of many stimuli including faces (Bruce & Young, 1986). Three experiments are reported, which investigated whether repetition priming is limited to the first repetition or whether subsequent repetitions continually act to increase the speed of face processing. Experiment 1 demonstrated that repetition can reduce categorization time for faces after the first exposure, and this effect is independent of practice effects. Experiment 2 demonstrated that the relationship between reaction time and number of repetitions fits a negative power function. Experiment 3 investigated how delay affects this power function. Delay was found to decrease the negative gradient of the power curve. The effects of priming and delay are discussed in terms of the predictions made by Burton's (1994) interactive activation and competition with learning (IACL) model of face recognition and accounts of automaticity.     

Charpentier (1891) on the size-weight illusion

This paper offers background for an English translation of an article originally published in 1891 by Augustin Charpentier (1852-1916), as well as a summary of it. The article is frequently described as providing the first experimental evidence for the size-weight illusion. A comparison of experiments on the judged heaviness of lifted weights carried out by Weber (1834) and by Charpentier (1891) supports the view that Charpentier's work deserves priority; review of other experimental studies on the size-weight illusion in the 1890s suggests that the idea that the illusion depended on "disappointed expectations," especially with respect to speed of lift, became dominant almost immediately following the publication of Charpentier's paper. The fate of this and other ideas, including "motor energy," in 20th-century research on the illusion is briefly described.     

Hidden talents in harsh conditions? A preregistered study of memory and reasoning about social dominance

Although growing up in stressful conditions can undermine mental abilities, people in harsh environments may develop intact, or even enhanced, social and cognitive abilities for solving problems in high‐adversity contexts (i.e. ‘hidden talents’). We examine whether childhood and current exposure to violence are associated with memory (number of learning rounds needed to memorize relations between items) and reasoning performance (accuracy in deducing a novel relation) on transitive inference tasks involving both violence‐relevant and violence‐neutral social information (social dominance vs. chronological age). We hypothesized that individuals who had more exposure to violence would perform better than individuals with less exposure on the social dominance task. We tested this hypothesis in a preregistered study in 100 Dutch college students and 99 Dutch community participants. We found that more exposure to violence was associated with lower overall memory performance, but not with reasoning performance. However, the main effects of current (but not childhood) exposure to violence on memory were qualified by significant interaction effects. More current exposure to neighborhood violence was associated with worse memory for age relations, but not with memory for dominance relations. By contrast, more current personal involvement in violence was associated with better memory for dominance relations, but not with memory for age relations. These results suggest incomplete transfer of learning and memory abilities across contents. This pattern of results, which supports a combination of deficits and ‘hidden talents,’ is striking in relation to the broader developmental literature, which has nearly exclusively reported deficits in people from harsh conditions. A video abstract of this article can be viewed at: https://youtu.be/e4ePmSzZsuc .     

PHYSICAL REALISM

Physical realism is the thesis that the world is more or less as present‐day physical theory says it is, i.e. a mind‐independent reality, that consists fundamentally of physical objects that have causal powers, are located in space and time, belong to natural kinds, and interact causally with each other in various natural kinds of ways. It is thus a modern form of physicalism that takes due account of the natural kinds structure of the world. It is a thesis that many present‐day scientific realists would surely accept. Indeed, some might say that physical realism just is scientific realism, but under another name. However, the argument that is presented for physical realism is not the standard one for scientific realism. It is not a two‐stage argument from the success of science to the truth of scientific theories to the reality of the entities postulated in these theories. It is more powerful than this, because it is more direct, and its premisses are more secure. It is more direct, because it develops what is basically a physicalist ontology as the only plausible metaphysical explanation of the new scientific image of the world. It is more secure, in that it does not depend, as the standard argument does, on any doubtful generalisations about the nature or role of scientific theory.     

HIV Infection and the Central Nervous System: A Primer

The purpose of this brief review is to prepare readers who may be unfamiliar with Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome (HIV/AIDS) and the rapidly accumulating changes in the epidemic by providing an introduction to HIV disease and its treatment. The general concepts presented here will facilitate understanding of the papers in this issue on HIV-associated neurocognitive disorders (HAND). Toward that end, we briefly review the biology of HIV and how it causes disease in its human host, its epidemiology, and how antiretroviral treatments are targeted to interfere with the molecular biology that allows the virus to reproduce. Finally, we describe what is known about how HIV injures the nervous system, leading to HAND, and discuss potential strategies for preventing or treating the effects of HIV on the nervous system.     

Parent-peer influence as a predictor of marijuana use.

Although there is some literature which discusses adolescent reference groups, none have utilized reference group theory to examine the relative impact of the parent and peer reference groups and to attempt to predict behavior among teenagers from this knowledge. This study attempts to correct this deficiency by examining the frequency of marijuana use in a nonrandom sample of college students from a large southwestern university. Ordinal type scales and tau-b provide a statistically strong degree of association between the type of reference group orientation and marijuana use. The results of this study show that the influence of the most salient reference group appears to be an important predictor of whether or not an individual may engage in the use of marijuana.