The beat goes on: rhythmic modulation of cortical potentials by imagined tapping

A frequency analysis was used to tag cortical activity from imagined rhythmic movements. Participants synchronized overt and imagined taps with brief visual stimuli presented at a constant rate, alternating between left and right index fingers. Brain potentials were recorded from across the scalp and topographic maps made of their power at the alternation frequency between left and right taps. Two prominent power foci occurred in each hemisphere for both overt and imagined taps, one over sensorimotor cortex and the other over posterior parietal cortex, with homologous foci in opposite hemispheres arising from oscillations 180 degrees out of phase. These findings demonstrate temporal isomorphism at a neural level between overt and imagined movements and illustrate a new approach to studying covert actions.     

Duplicate publication and ‘paper inflation’ in the fractals literature

The similarity of documents in a large database of published Fractals articles was examined for redundancy. Three different text matching techniques were used on published Abstracts to identify redundancy candidates, and predictions were verified by reading full text versions of the redundancy candidate articles. A small fraction of the total articles in the database was judged to be redundant. This was viewed as a lower limit, because it excluded cases where the concepts remained the same, but the text was altered substantially. Far more pervasive than redundant publications were publications that did not violate the letter of redundancy but rather violated the spirit of redundancy. There appeared to be widespread publication maximization strategies. Studies that resulted in one comprehensive paper decades ago now result in multiple papers that focus on one major problem, but are differentiated by parameter ranges, or other stratifying variables. This ‘paper inflation’ is due in large part to the increasing use of metrics (publications, patents, citations, etc) to evaluate research performance, and the researchers’ motivation to maximize the metrics. The views in this paper are solely those of the authors, and do not necessarily represent the views of the Department of the Navy or any of its components, UNAM, University of Virginia or University of Karlsruhe.     

Detecting emotional faces and features in a visual search paradigm: are faces special?

In 2 experiments, participants were presented schematic faces with emotional expressions (threatening, friendly) in a neutral-faces context or neutral expressions in an emotional-faces context. These conditions were compared with detection performance in displays containing key features of emotional faces not forming the perceptual gestalt of a face. Supporting the notion of a threat detection advantage, Experiment 1 found that threatening faces were faster detected than friendly faces, whereas no difference emerged between the corresponding feature conditions. Experiment 2 increased task difficulty with a backward masking procedure and found corresponding results. In neither of the studies was the threat detection advantage associated with reduced accuracy. However, features were, in general, detected faster than faces when task difficulty was high.     

Informational mood impact on effort-related cardiovascular response: the diagnostic value of mood counts

Drawing on the mood-behavior model (G. H. E. Gendolla, 2000), 2 experiments examined moods' informational impact on effort-related cardiovascular response. After being induced into positive versus negative moods, participants performed a memory task (Experiment 1) or a letter-cancellation task (Experiment 2). Half the participants received a cue that their mood could have been manipulated. As expected, both studies found stronger reactivity of systolic blood pressure in a negative mood than in a positive mood when no cue was provided. This effect diminished in the cue conditions. Additionally, achievement corresponded to systolic blood pressure reactivity (Experiment 1), the cue manipulation had no effect on mood, and mood had a congruency effect on subjective task difficulty in the no-cue conditions (Experiment 2).     

Knowledge of partner's ability as a moderator of group motivation gains: an exploration of the Köhler discrepancy effect

O. K?hler (1926, 1927) found that less able performers tried harder as team members under conjunctive task demands (Kohler motivation gain effect) and that the greatest gain occurred with moderately discrepant coworker abilities (K?hler discrepancy effect). Recent investigations have reproduced K?hler's overall motivation gain but not the discrepancy effect. The present research examined whether workers' foreknowledge of task abilities--present in Kohler's research, absent in contemporary studies--moderates the discrepancy effect. Participants worked alone or in 2-person teams under conjunctive task demands. Experiment 1 manipulated foreknowledge of ability. Experiment 2 manipulated discrepancy: a (confederate) teammate performed slightly, moderately, or substantially better. Both experiments found (a) overall motivation gains and (b) discrepancy moderation under foreknowledge conditions. Implications for understanding group motivation gains are discussed.     

The joint effect of informational mood impact and performance-contingent consequences on effort-related cardiovascular response

Drawing on the mood-behavior model (G. H. E. Gendolla, 2000) and J. W. Brehm and E. A. Self's (1989) theory of effort mobilization, 2 experiments investigated the joint effect of mood, task difficulty, and performance-contingent consequences on effort-related cardiovascular response. Informational mood impact on demand appraisals and performance-contingent consequences had a joint effect on effort mobilization. When consequences were noncontingent on performance, mood interacted with task difficulty to determine cardiovascular reactivity in the shape of a cross-over interaction pattern. Yet when positive consequences were performance contingent, cardiovascular reactivity strongly increased only in the negative-mood/difficult-task condition--the subjectively appraised high necessary effort was now justified. Implications for the role of mood in motivation are discussed.     

Forming subjective representations of subjective representations: evidence of a subjective status bias

In 3 studies and 2 pilot experiments, the author examined whether attending to the subjective status of mental representations would affect the ways humans view representational contents. The author found that simple drawing tasks were executed differently depending on whether or not the subject of the drawing was defined as a mental content (belief, imagination, perception). The results challenged particular lay epistemological concepts. They were partly accounted for by Gricean conversational rules (H. P. Grice, 1975), but the author postulated a subjective status bias to fully explain them. The discussion and recommendations for research center on the nature of this bias and relate it either to a tendency to conceive subjective representations as vague shadows of reality, or to an increased impact of the law of pregnance.     

Speed-accuracy modulation in case of conflict: the roles of activation and inhibition

This study investigated how the speed-accuracy balance is modulated by changes in the time course of motor activation and inhibition of a primed response. Responses and event-related brain potentials were recorded in a paradigm in which the first stimulus indicated the correct response with 80% validity. The remaining 20% of the trials required no response (no-go) or a response opposite to the cued hand (change trials). Subjects were instructed either to balance speed and accuracy or to emphasize speed at the cost of accuracy. Analyses of error patterns, reaction time distributions and brain potentials show that subjects can modulate the amount of activation of the primed response. More surprisingly, the engagement of inhibition of the response also varied with the speed-accuracy instruction. The results are consistent with a model where the frontothalamic loop actively controls both the activation and the inhibition of responses, depending on the current task requirements. This study was supported by the Netherlands Organization of Scientific Research (NWO) grant numbers 575-63-082 and 575-25-004. The work of Dr. Band and Dr. Ridderinkhof was supported by grants from the Royal Netherlands Academy of Arts and Sciences     

Disorders of classificatory activity in aphasia

Two nonverbal tasks of classificatory activity ("class inclusion" and "class intersection") were administered to 46 aphasics, 28 normal controls, 19 nonaphasic left-brain-damaged and 17 right-hemisphere-damaged patients in order to study if aphasic patients are more impaired than nonaphasic brain-damaged patients on these two tasks of elementary logic and if a relationship exists within the aphasic patients between inability to perform the tasks of classifiactory activity and impairment of the semantic-lexical level of integration of language. Results were for the most part in line with expectations because aphasics scored worse than normal controls and nonaphasic brain-damaged patients (even if the difference reached the level of statistical significance only on the test of "class intersection") and within the aphasic patients the worst results were obtained by subjects presenting clear signs of semantic-lexical disintegration.     

Extending Psychometric Norms for Pre-Cardiac Transplantation Evaluations: The Florida Cohort, 1990–1996

Multidisciplinary pre-cardiac transplantation evaluations determine an individual's ability to benefit from potential transplantation. Psychologists are routinely consulted to perform psychological evaluations and testing to examine the candidate's current functioning and to forecast future functioning in the event of transplantation. The establishment of appropriate norms for psychological tests is an ethical imperative to provide high quality psychological consultations that maximize the utility of information gathered. The purpose of this paper is to present pre-cardiac transplant norms for a battery of psychological tests in a large population of consecutive transplant candidates. Together with other recently published norms on alternative test batteries, these norms allow the transplant psychologist to select from a range of psychological tests that span multiple domains of critical importance including the affective, behavioral, coping, cognitive, and health related quality of life domains. These norms appear to set a standard of practice for the use of psychological tests by a consulting transplantation psychologist.