Are movements prepared in parts? Not under compatible (naturalized) conditions

This set of experiments is concerned with the specification of movement parameters hypothesized to be involved in the initiation of movement. Experiment 1 incorporated the precuing method developed by Rosenbaum in which a precue provided partial information of the upcoming movement before the stimulus to move. Under conditions in which precues were provided by letter symbols and stimuli were color-coded dots mapped to response keys. Rosenbaum found reaction times to be slower for the specification of arm than for direction, and both to be slower than the specification of extent. In Experiment 1, using precue and stimulus conditions that paralleled those employed by Rosenbaum, we obtained very similar findings. The three follow-up experiments extended these findings to more naturalized stimulus-response compatible conditions. We used a method in which precues and stimuli were directly specified through vision and mapped in a one-to-one manner with responses. In Experiment 2, although reacion times decreased as a function of the number of parameters precued, there were no systematic effects of precuing particular parameters. In Experiments 3 and 4, we incorported an ambiguous precue that, while serving to reduce task uncertainty, failed to provide any specific information as to the arm, direction, or extent of the upcoming movement. Initiation times did not systematically vary as a function of the type of parameter precued nor were there significant differences between specific and ambiguous precue conditions. In sum, only in Experiment 1 in which precues and stimuli involved complex cognitive transformations was there support for Rosenbaum's parameter specification model. When we employed highly compatible conditions, designed to reflect a real-world environment, we failed to obtain any tendency for movement parameters to be serially specified. We discuss grounds for suspecting the generality of parameter specification models and propose an alternative approach that is consonant with the dynamic characteristics of the motor control system.     

Lessons learned in deep brain stimulation for movement and neuropsychiatric disorders

The introduction of deep brain stimulation (DBS) as a treatment for medication-refractory essential tremor in the late 1980s revealed, for the first time, that "chronically" implanted brain hardware had the potential to modulate neurologic function with surprisingly low morbidity. Over time, the therapeutic promise of DBS has become evident in Parkinson's disease and dystonia. In some experienced centers, complex tremor disorders, such as posttraumatic Holmes tremor and the tremor of multiple sclerosis, are being increasingly targeted. More recently, other indications, including obsessive-compulsive disorder, Tourette's syndrome, major depression, and chronic pain, have been proposed. As the field has expanded, our knowledge about potential cognitive side effects of DBS has also expanded. This article reviews the current knowledge regarding the impact of stimulation of the subthalamic nucleus, globus pallidus internus, and ventralis intermedius nucleus of the thalamus on symptoms in essential tremor, Parkinson's disease, and dystonia. Also discussed are the emerging targets, what is known about the cognitive sequelae of DBS, and what has been learned about the complications and therapeutic failures.     

Wailing babies in her wake

The scientific study of child witnesses has influenced both developmental science and jurisprudence concerning children. Focusing on the author's own studies, 4 categories of research are briefly reviewed: (a) children's eyewitness memory and suggestibility; (b) memory for traumatic events in childhood; (c) disclosure of child sexual abuse; and (d) experiences of child victim/witnesses within the legal system. Implications for psychology and for legal practice are discussed.     

The role of age in the perceptions of politics--job performance relationship: a three-study constructive replication

This research examined the interaction of organizational politics perceptions and employee age on job performance in 3 studies. On the basis of conservation of resources theory, the authors predicted that perceptions of politics would demonstrate their most detrimental effects on job performance for older workers. Results across the 3 studies provided strong support for the hypothesis that increases in politics perceptions are associated with decreases in job performance for older employees and that perceptions of politics do not affect younger employees' performance. Implications of these results, strengths and limitations, and directions for future research are discussed.     

A solid-state device for presenting moving shadows

The use of luminescent panels controlled by solid-state circuitry to produce moving shadows is described. Advantages include lack of vibration, noise, and heat.     

Bootstrapping in a language of thought: a formal model of numerical concept learning

In acquiring number words, children exhibit a qualitative leap in which they transition from understanding a few number words, to possessing a rich system of interrelated numerical concepts. We present a computational framework for understanding this inductive leap as the consequence of statistical inference over a sufficiently powerful representational system. We provide an implemented model that is powerful enough to learn number word meanings and other related conceptual systems from naturalistic data. The model shows that bootstrapping can be made computationally and philosophically well-founded as a theory of number learning. Our approach demonstrates how learners may combine core cognitive operations to build sophisticated representations during the course of development, and how this process explains observed developmental patterns in number word learning.     

Low-effort thought promotes political conservatism

The authors test the hypothesis that low-effort thought promotes political conservatism. In Study 1, alcohol intoxication was measured among bar patrons; as blood alcohol level increased, so did political conservatism (controlling for sex, education, and political identification). In Study 2, participants under cognitive load reported more conservative attitudes than their no-load counterparts. In Study 3, time pressure increased participants' endorsement of conservative terms. In Study 4, participants considering political terms in a cursory manner endorsed conservative terms more than those asked to cogitate; an indicator of effortful thought (recognition memory) partially mediated the relationship between processing effort and conservatism. Together these data suggest that political conservatism may be a process consequence of low-effort thought; when effortful, deliberate thought is disengaged, endorsement of conservative ideology increases.     

Misapplying autonomy: why patient wishes cannot settle treatment decisions

Theoretical Medicine and Bioethics - The principle of autonomy is widely recognized to be of utmost importance in bioethics; however, we argue that this principle is often misapplied when one fails...     

Memory for child sexual abuse information: Simulated memory error and individual differences

Building on the simulated-amnesia work of Christianson and Bylin (Applied Cognitive Psychology, 13, 495–511, 1999), the present research introduces a new paradigm for the scientific study of memory of childhood sexual abuse information. In Session 1, participants mentally took the part of an abuse victim as they read an account of the sexual assault of a 7-year-old. After reading the narrative, participants were randomly assigned to one of four experimental conditions: They (1) rehearsed the story truthfully (truth group), (2) left out the abuse details of the story (omission group), (3) lied about the abuse details to indicate that no abuse had occurred (commission group), or (4) did not recall the story during Session 1 (no-rehearsal group). One week later, participants returned for Session 2 and were asked to truthfully recall the narrative. The results indicated that, relative to truthful recall, untruthful recall or no rehearsal at Session 1 adversely affected memory performance at Session 2. However, untruthful recall resulted in better memory than did no rehearsal. Moreover, gender, PTSD symptoms, depression, adult attachment, and sexual abuse history significantly predicted memory for the childhood sexual abuse scenario. Implications for theory and application are discussed.