Same-hand and different-hand finger pairings in two-choice reaction time: presence or absence of response competition?

Several two-choice reaction time experiments have compared conditions in which the two possible responses were from the same hand (same-hand pairing) or from different hands (different-hand pairing). Studies that used only the two relevant fingers on response keys reported shorter reaction times for the different-hand pairing. In other studies, two additional but irrelevant fingers were also in contact with response keys. These fingers were irrelevant in the sense that they never were required to respond. With this procedure, equivalent reaction times were found between same-hand and different-hand pairings. Reeve and Proctor (1988) recently have argued that using only two fingers results in response competition between the two fingers from the same hand, yielding shorter reaction times for the different-hand pairing condition. In contrast, when four fingers are placed on response keys, response competition should be absent for both the same-hand and the different-hand pairing conditions, resulting in equivalent reaction times. In the present work, reaction times associated with the same-hand pairing condition remained unchanged, irrespective of the number of fingers positioned on keys. In the different-hand pairing condition, reaction times were found to be longer when four fingers were used than when only two fingers rested on response keys. Thus, when four fingers are placed on keys, response competition appears to be present rather than absent. Other results showed that the response competition found in the different-hand pairing condition decreases with practice.     

Are movements/proprioception effective time-keeping mediators? The input hypothesis re-visited

Based upon the experimental literature surveyed, and given that time-keeping accuracy (i.e., constant error, absolute error, beneficial anticipation) is the appropriate performance dimension to consider, there appears to be virtually no support for the speculation that proprioception serves as an effective mediator for conscious time-keeping judgements. For the most part, individuals afforded movements during the interval to be timed did not perform significantly more precisely than did those people deprived of such time-filling movements, nor did they consistently estimate time with significantly less variability. On this basis, and because other predictions of the Input Hypothesis examined herein (left/right hand covariance, practice by movement group interaction and effect of different levels of proprioception) were not experimentally supported, the validity of the Input Hypothesis was rejected.     

Study of the energy correlates in the learning of a complex self-paced cyclical skill

This study examines changes in movement parameters and energy expense during the learning of a cyclical task performed on a “ski simulator”. Five subjects performed five training sessions (each of four 4-minute learning periods separated by a 4-minute rest) and then took a post-test one week later. The instructions were to make movements which were “as wide and frequent as possible”. The subjects were filmed on videotape and their oxygen intake was measured. Movement amplitude, movement frequency, oxygen intake, and a “movement cost” index were calculated. The results indicated a significant increase in movement amplitude and oxygen intake and a decrease in movement cost. The movement frequency of all subjects tended towards the same final value. Two simultaneous changes could occur, with large individual differences: an increase in energy expense due to the increase in the amount of work done, a decrease in energy expense due to the increase in movement economy.     

Effects of context on auditory stream segregation

The authors examined the effect of preceding context on auditory stream segregation. Low tones (A), high tones (B), and silences (-) were presented in an ABA- pattern. Participants indicated whether they perceived 1 or 2 streams of tones. The A tone frequency was fixed, and the B tone was the same as the A tone or had 1 of 3 higher frequencies. Perception of 2 streams in the current trial increased with greater frequency separation between the A and B tones (Delta f). Larger Delta f in previous trials modified this pattern, causing less streaming in the current trial. This occurred even when listeners were asked to bias their perception toward hearing 1 stream or 2 streams. The effect of previous Delta f was not due to response bias because simply perceiving 2 streams in the previous trial did not cause less streaming in the current trial. Finally, the effect of previous ?f was diminished, though still present, when the silent duration between trials was increased to 5.76 s. The time course of this context effect on streaming implicates the involvement of auditory sensory memory or neural adaptation.     

The personality basis of justice: The five‐factor model as an integrative model of personality and procedural fairness effects on cooperation

Building upon the self‐based model of cooperation (De Cremer & Tyler, 2005 ), the present study investigates the relationship between the five‐factor model (FFM) and cooperation. Study 1 (N = 56), an experiment conducted in the laboratory, and Study 2 (N = 116), a field study conducted in an organisational context, yielded a moderator effect between neuroticism and procedural fairness in explaining cooperation. Study 3 (N = 177) showed that this moderator effect was mediated by the self‐uncertainty and relational variables proposed by the self‐based model of cooperation. It is concluded that the FFM is useful in explaining cooperation and contributes to a better understanding of (procedural) fairness effects. Moreover, the necessity to build integrative, multi‐level models that combine core and surface aspects of personality to explain the effects of fairness on cooperation is elaborated upon. Copyright © 2008 John Wiley & Sons, Ltd.     

Inverted-U effects generalize to the judgment of subjective properties of faces

Researchers studying absolute identification have long known that it takes more time to identify a stimulus in the middle of a range than one at the extremes. That is, there is an inverted-U relation between mean response time and response position. In this task, an inverted-U relation also exists between response uncertainty and response position. Similarly, an inverted-U relation between mean response time and response position has been found for psychometric measures involving questions about the self. However, psychophysicists explain these inverted-U effects differently than do self-schema researchers. We propose an integrative framework in which task constraints explain these effects. To verify the generality of these inverted-U effects, we hypothesized that they would exist in three tasks having similar constraints--in this case, tasks involving the judgment of subjective properties of faces on a Likert-type scale. Our results are consistent with this hypothesis. We discuss the relevance of the results for other applications of Likert-type scales.     

Social Influence Dynamics in Aptitude Tasks

Learning and, more generally, the development of cognitive processes in children has been thought to depend on the nature of the conflict induced by confrontation with others (i.e., socio-cognitive conflict). The aim of this article is to extend this notion to social-influence situations involving adolescents and young adults through the presentation of a model that explains social influence in aptitude tasks. This model takes into account the differences or similarities of the competencies of the source and target. It conceptualizes the social versus epistemic regulations of conflict in terms of an identity threat that can be induced by social comparison. To illustrate parts of the model, several experiments are briefly summarized. One demonstrates the conflict regulation dynamics involved in the similarities or differences of the sources' and targets' competencies, while the others show how social-influence dynamics are modified by the presence or absence of a threat to self-competence. This revised version was published online in August 2006 with corrections to the Cover Date.