A theory of dynamic occluded and illusory object perception

Humans see whole objects from input fragmented in space and time, yet spatiotemporal object perception is poorly understood. The authors propose the theory of spatiotemporal relatability (STR), which describes the visual information and processes that allow visible fragments revealed at different times and places, due to motion and occlusion, to be assembled into unitary perceived objects. They present a formalization of STR that specifies spatial and temporal relations for object formation. Predictions from the theory regarding conditions that lead to unit formation were tested and confirmed in experiments with dynamic and static, occluded and illusory objects. Moreover, the results support the identity hypothesis of a common process for amodal and modal contour interpolation and provide new evidence regarding the relative efficiency of static and dynamic object formation. STR postulates a mental representation, the dynamic visual icon, that briefly maintains shapes and updates positions of occluded fragments to connect them with visible regions. The theory offers a unified account of interpolation processes for static, dynamic, occluded, and illusory objects.     

The social context of adolescent suicide attempts: interactive effects of parent, peer, and school social relations

An ecological developmental model of adolescent suicidality was used to inform a hierarchical logistic regression analysis of longitudinal interactions between parent, peer, and school relations and suicide attempts. Reanalyzing data from the National Longitudinal Study of Adolescent Health, it was found that parent relations were the most consistent protective factor, and among boys with prior suicide attempts, school relations augmented the effects of parent relations when peer relations were low. Results indicated the need to understand suicidal behavior as a component of interactive social processes in the design of clinical interventions.     

Mathematics anxiety affects counting but not subitizing during visual enumeration

Individuals with mathematics anxiety have been found to differ from their non-anxious peers on measures of higher-level mathematical processes, but not simple arithmetic. The current paper examines differences between mathematics anxious and non-mathematics anxious individuals in more basic numerical processing using a visual enumeration task. This task allows for the assessment of two systems of basic number processing: subitizing and counting. Mathematics anxious individuals, relative to non-mathematics anxious individuals, showed a deficit in the counting but not in the subitizing range. Furthermore, working memory was found to mediate this group difference. These findings demonstrate that the problems associated with mathematics anxiety exist at a level more basic than would be predicted from the extant literature.     

Fooled by the brain: Re-examining the influence of neuroimages

A series of highly-cited experiments published in 2008 demonstrated a biasing effect of neuroimages on lay perceptions of scientific research. More recent work, however, has questioned this bias, particularly within legal contexts in which neuroscientific evidence is proffered by one of the parties. The present research moves away from the legal framework and describes five experiments that re-examine this effect. Experiments 1 through 4 present conceptual and direct replications of some of the original 2008 experiments, and find no evidence of a neuroimage bias. A fifth experiment is reported that confirms that, when laypeople are allowed multiple points of reference (e.g., when directly comparing neuroimagery to other graphical depictions of neurological data), a neuroimage bias can be observed. Together these results suggest that, under the right conditions, a neuroimage might be able to bias judgments of scientific information, but the scope of this effect may be limited to certain contexts.     

Grateful individuals are not suicidal: Buffering risks associated with hopelessness and depressive symptoms

With suicidal behavior serving as a leading cause of injury and death around the world, researchers must expand ongoing efforts to uncover protective factors. In this study, we examined if gratitude mitigated existing risk factors for suicide. Specifically, we predicted that gratitude moderates the relationship between suicidal ideation and (a) hopelessness and (b) depressive symptoms in a sample of 369 diverse undergraduate students. Results indicate that for people who are highly grateful, both hopelessness and depressive symptoms are less likely to be associated with thoughts and intentions to kill oneself. The findings demonstrate the value of integrating protective factors against suicidality, including character strengths such as gratitude, into existing theories that tend to be limited to vulnerability factors. We offer tentative ideas for enhancing the impact of suicide prevention and intervention programs by directly addressing gratitude, which has been shown to be highly modifiable.     

A theory of the normative force of pleas

A familiar feature of our moral responsibility practices are pleas: considerations, such as “That was an accident”, or “I didn’t know what else to do”, that attempt to get agents accused of wrongdoing off the hook. But why do these pleas have the normative force they do in fact have? Why does physical constraint excuse one from responsibility, while forgetfulness or laziness does not? I begin by laying out R. Jay Wallace’s (Responsibility and the moral sentiments, 1994) theory of the normative force of excuses and exemptions. For each category of plea, Wallace offers a single governing moral principle that explains their normative force. The principle he identifies as governing excuses is the Principle of No Blameworthiness without Fault: an agent is blameworthy only if he has done something wrong. The principle he identifies as governing exemptions is the Principle of Reasonableness: an agent is morally accountable only if he is normatively competent. I argue that Wallace’s theory of exemptions is sound, but that his account of the normative force of excuses is problematic, in that it fails to explain the full range of excuses we offer in our practices, especially the excuses of addiction and extreme stress. I then develop a novel account of the normative force of excuses, which employs what I call the “Principle of Reasonable Opportunity,” that can explain the full range of excuses we offer and that is deeply unified with Wallace’s theory of the normative force of exemptions. An important implication of the theory I develop is that moral responsibility requires free will.     

Stress-Induced Drinking in Parents of Boys with Attention-Deficit-Hyperactivity Disorder: Heterogeneous Groups in an Experimental Study of Adult-Child Interactions

Research on whether parents of children with externalizing disorders are at elevated risk for alcohol problems is equivocal. To reduce this ambiguity, we examined how individual differences in stress reactivity might moderate the drinking behavior of such parents. Parents (119 mothers, 44 fathers) of ADHD sons interacted with different child confederates during each of two counter-balanced sessions. In one, the confederate portrayed a friendly, cooperative, “normal” boy; in the other, the confederate portrayed a “deviant” boy who exhibited behavior characteristic of externalizing disorders. Following each interaction, parents were given an opportunity for ad lib consumption of alcohol while anticipating a second interaction. Latent class analysis identified three subgroups of parents using distress scores and alcohol consumption: minimal stress reactivity; reacts to child deviance with increased distress, but not increased drinking; marked stress-induced drinking. Decisions about the nature and proper treatment of parents raising children with ADHD may be compromised by failure to attend to individual differences in stress reactivity and inclinations to use drinking to cope.     

Conditioned suppression/avoidance as a procedure for testing hearing in birds: The domestic pigeon (Columba livia)

Although the domestic pigeon is commonly used in learning experiments, it is a notoriously difficult subject in auditory psychophysical experiments, even those in which it need only respond when it detects a sound. This is because pigeons tend to respond in the absence of sound—that is, they have a high false-positive rate—which makes it difficult to determine a pigeon’s audiogram. However, false positives are easily controlled in the method of conditioned suppression/avoidance, in which a pigeon is trained to peck a key to obtain food and to stop pecking whenever it detects a sound that signals impending electric shock. Here, we describe how to determine psychophysical thresholds in pigeons using a method of conditioned suppression in which avoidable shock is delivered through a bead chain wrapped around the base of a pigeon’s wings. The resulting audiogram spans the range from 2 to 8000 Hz; it falls approximately in the middle of the distribution of previous pigeon audiograms and supports the finding of Kreithen and Quine (Journal of Comparative Physiology 129:1–4, 1979) that pigeons hear infrasound.     

Beyond the Grand Illusion: What Change Blindness Really Teaches Us About Vision

Experiments on scene perception and change blindness suggest that the visual system does not construct detailed internal models of a scene. These experiments therefore call into doubt the traditional view that vision is a process in which detailed representations of the environment must be constructed. The non-existence of such detailed representations, however, does not entail that we do not perceive the detailed environment. The “grand illusion hypothesis” that our visual world is an illusion rests on (1) a problematic “reconstructionist” conception of vision, and (2) a misconception about the character of perceptual experience.