Efficiency of visual selective attention is related to the type of target

Lavie and Cox (1997, Psychological Science, 8, 395) suggested that stimuli outside the focus of attention can have more distracting effects when the task requires less attention than when it requires more. This idea provides an explanation for the proposed dissociation found between two forms of attentional control (Folk & Remington, 1998, Journal of Experimental Psychology: Human Perception and Performance, 24, 847). This proposal was based on a red (green) distractor that captured attention when a red (green) target was used, but not when a green (red) target was used, and the further result that, if there were no distractor, reaction times were faster than with either type of distractor. We tested whether a target that requires serial search would eliminate the dissociation. With the same targets used by Folk and Remington (ones that can be found with parallel search), we also obtained a dissociation. However, with the serial-search targets, dissociation was not found. Our interpretation is that the dissociation represents two forms of the same attentional process.     

Reproducibility of fMRI-determined language lateralization in individual subjects

This study investigated within-subject test-retest reproducibility (i.e., reliability) of language lateralization obtained with fMRI. Nine healthy subjects performed the same set of three different language tasks during two fMRI sessions on separate days (verb generation, antonym generation, and picture naming). A fourth task analysis was added in which the three tasks were analyzed conjointly (combined task analysis, CTA). The CTA targets brain areas that are commonly used in different language tasks, aiming more selectively at language-critical structures. The number of active voxels (i.e., robustness) and calculated lateralization index (LI) were compared across sessions, tasks, subjects, and two a priori defined volumes of interest (classical language regions versus whole hemisphere) for a wide range of statistical thresholds. Robustness and reliability strongly varied between task analyses. The CTA was a robust detector of language-related brain activity, in contrast to the single task approaches. The CTA and verb generation task allowed for reliable calculation of the LI. Higher thresholds yielded a clear increase in left lateralization, which was largest when calculated from active voxels in classical language regions.     

Thought-action fusion in individuals with OCD symptoms.

Rachman (Rachman, S. (1993). Obsessions, responsibility, and guilt. Behaviour Research and Therapy, 31, 149-154) suggested that patients with OCD may interpret thoughts as having special importance, thus experiencing thought-action fusion (TAF). Shafran, Thordarson and Rachman (Shafran, R., Thordarson, D. S. & Rachman, S. (1996). Thought-action fusion in obsessive compulsive disorder. Journal of Anxiety Disorders, 710, 379-391) developed a questionnaire (TAF) and found that obsessives scored higher than non-obsessives on the measure. In the current study, we modified the TAF to include a scale that assessed the "likelihood of events happening to others" as well as ratings of the responsibility and cost for having these thoughts. Replicating previous findings, we found that individuals with OC symptoms gave higher ratings to the likelihood of negative events happening as a result of their negative thoughts. Individuals with OC symptoms also rated the likelihood that they would prevent harm by their positive thoughts higher than did individuals without OC symptoms. These results suggest that the role of thought-action fusion in OCs may extend to exaggerated beliefs about thoughts regarding the reduction of harm.     

Parallelism and Functionalism

It has recently been argued by Paul Thagard (1986) that parallel computational models of cognition demonstrate the falsity of the popular theory of mind known as functionalism. It is my contention that his argument is seriously mistaken and rests on a misunderstanding of the functionalist position. While my primary aim is to defend functionalism from Thagard's attack, in the process I hope to provide some much needed clarification of matters both philosophical and computational. Since I intend to untangle issues that are often troublesome in cognitive science, the paper should prove useful even for those unfamiliar with Thagard's original piece.     

Allocation of attention in texture segregation, visual search, and location-precuing paradigms

Is there a common mechanism (or set of mechanisms) that controls the allocation of spatial attention in texture segregation, visual search, and location-precuing tasks? This question was addressed by comparing data from our previous research on location-cuing and search tasks with data from a new set of experiments on texture segregation, in which a common set of stimuli was used across the three paradigms. However, when we ranked the scores for the targets on texture segregation speed, search rate, and improvement due to precuing effects, agreement between these measures was less than perfect. Further analyses of these results led to the following conclusions: (a) speed of texture segregation is affected by perceptual aspects of the display other than the attentional salience of a particular target; (b) visual search rate and the size of precuing effects are strongly related over most of the set of targets we used; and (c) some cases in which search rate was not consistent with size of precue effects may be related to the presence of nearby distractors in the search task.     

Young adolescents’ emotional and regulatory responses to positive life events: Investigating temperament,attachment, and event characteristics

Very little is known about what factors predict variations in responses to positive events among youth. Consequently, we examined young adolescents’ positive emotional reactions and their savoring and dampening responses to their most intense positive event across a four-day period. The investigated predictors were parent-reported adolescent temperament, adolescent-reported attachment security with mothers and fathers, and researcher-coded event characteristics. The sample was 56 youth (31 boys, 10–14 years of age). More support was found for temperament than attachment. Specifically, effortful control predicted more savoring and sustained positive affect (PA) about the events, whereas negative emotionality predicted more dampening. Adolescents’ reports of more secure attachment to fathers were marginally linked to more savoring of their positive event. Girls reported higher levels of initial PA yet endorsed more dampening responses than boys. Event type (interpersonal vs. not) was unrelated to responses to the events. Overall, this study offers new information on the development of PA regulation and responses to positive events in youth.     

On Muddled Reasoning and Mediation Modeling

The hope of mediation modeling is that psychologists can go beyond tests of association to truly uncover mechanisms of change. We argue this hope can be realized only if psychologists make important distinctions regarding causality and inference. From the perspective of Aristotelian philosophy, mediation models are sequences of efficient causes, and psychologists should therefore seek to identify those persons who can be traced through the entire sequence successfully. By reanalyzing data from two mediation studies we demonstrate that contemporary, aggregate methods of analysis are not suitable for this task because they are instead focused on making inferences about population parameters. In both studies alternative, person-centered methods revealed that majorities of participants were not traceable through the statistically significant mediation models.     

Predicting others' actions via grasp and gaze: evidence for distinct brain networks

During social interactions, how do we predict what other people are going to do next? One view is that we use our own motor experience to simulate and predict other people's actions. For example, when we see Sally look at a coffee cup or grasp a hammer, our own motor system provides a signal that anticipates her next action. Previous research has typically examined such gaze and grasp-based simulation processes separately, and it is not known whether similar cognitive and brain systems underpin the perception of object-directed gaze and grasp. Here we use functional magnetic resonance imaging to examine to what extent gaze- and grasp-perception rely on common or distinct brain networks. Using a 'peeping window' protocol, we controlled what an observed actor could see and grasp. The actor could peep through one window to see if an object was present and reach through a different window to grasp the object. However, the actor could not peep and grasp at the same time. We compared gaze and grasp conditions where an object was present with matched conditions where the object was absent. When participants observed another person gaze at an object, left anterior inferior parietal lobule (aIPL) and parietal operculum showed a greater response than when the object was absent. In contrast, when participants observed the actor grasp an object, premotor, posterior parietal, fusiform and middle occipital brain regions showed a greater response than when the object was absent. These results point towards a division in the neural substrates for different types of motor simulation. We suggest that left aIPL and parietal operculum are involved in a predictive process that signals a future hand interaction with an object based on another person's eye gaze, whereas a broader set of brain areas, including parts of the action observation network, are engaged during observation of an ongoing object-directed hand action.     

Workers' Compensation and Respondeat Superior Liability Legal Cases Involving Salespersons' Misuse of Alcohol

Legal cases where salespersons' misuse of alcohol resulted in either workers' compensation or respondeat superior liability cases are reviewed. Three main areas emerged which may require corporate attention: (1) salesperson travel including use of a home office, (2) condoning of alcohol use by corporations, and (3) the use of a company car. Corporation policy issues are discussed, as well as appropriate training suggested at the corporate and collegiate levels.