Do humans produce the speed–accuracy trade-off that maximizes reward rate?

In this paper we investigate trade-offs between speed and accuracy that are produced by humans when confronted with a sequence of choices between two alternatives. We assume that the choice process is described by the drift diffusion model, in which the speed–accuracy trade-off is primarily controlled by the value of the decision threshold. We test the hypothesis that participants choose the decision threshold that maximizes reward rate, defined as an average number of rewards per unit of time. In particular, we test four predictions derived on the basis of this hypothesis in two behavioural experiments. The data from all participants of our experiments provide support only for some of the predictions, and on average the participants are slower and more accurate than predicted by reward rate maximization. However, when we limit our analysis to subgroups of 30–50% of participants who earned the highest overall rewards, all the predictions are satisfied by the data. This suggests that a substantial subset of participants do select decision thresholds that maximize reward rate. We also discuss possible reasons why the remaining participants select thresholds higher than optimal, including the possibility that participants optimize a combination of reward rate and accuracy or that they compensate for the influence of timing uncertainty, or both.     

Language nonselective access to phonological representations: Evidence from Chinese–English bilinguals

Four experiments with Chinese–English bilinguals were conducted in order to investigate the hypothesis of language nonselective access to an integrated lexicon for bilingual phonological representations. Results of a naming task (in Experiments 1 and 2) and a lexical decision task (in Experiments 3 and 4) showed homophone priming effects regardless of priming direction (English to Chinese, or Chinese to English) or English proficiency. Our findings are compatible with the BIA+ model of bilingual processing, provide further support for the hypothesis of language nonselective access to an integrated lexicon for bilingual phonological representations, and extend the hypothesis to language pairs with very different writing systems.     

Influence of biological kinematics on abstract concept processing

Though figure–ground assignment has been shown to be probably affected by recognizability, it appears sensible that object recognition must follow at least the earlier process of figure–ground segregation. To examine whether or not rudimentary object recognition could, counterintuitively, start even before the completion of the stage of parsing in which figure–ground segregation is done, participants were asked to respond, in a go/no-go fashion, whenever any out of 16 alternative connected patterns (that constituted familiar stimuli in the upright orientation) appeared. The white figure of the to-be-attended stimulus—target or foil—could be segregated from the white ambient ground only by means of a frame surrounding it. Such a frame was absent until the onset of target display. Then, to manipulate organizational quality, the greyness of the frame was either gradually increased from zero (in Experiment 1) or changed abruptly to a stationary level whose greyness was varied between trials (in Experiments 2 and 3). Stimulus recognizability was manipulated by orientation angle. In all three experiments the effect of recognizability was found to be considerably larger when organizational quality was minimal due to an extremely faint frame. This result is argued to be incompatible with any version of a serial thesis suggesting that processing aimed at object recognition starts only with a good enough level of organizational quality. The experiments rather provide some support to the claim, termed here “early interaction hypothesis”, positing interaction between early recognition processing and preassignment parsing processes.     

Transfer of calibration in dynamic touch: What do perceivers learn when they learn about length of a wielded object?

Successfully performing everyday behaviours requires that perceptions and actions are properly calibrated to environmental properties. In three experiments, the authors tested whether calibration was specific to perception of a particular property of a wielded object from a particular grasp position on that object. The experiments investigate whether transfer of recalibration occurs across changes in grasp position (Experiment 1), object property (Experiment 2), and grasp position and object property (Experiment 3). The results suggest that a complete transfer of recalibration occurred in each case. Such results are consistent with recent research on dynamic touch and suggest that rather than recalibrating participants to one particular property of the wielded objects, feedback about a particular property served to recalibrate participants to the properties of the rod set as a whole.     

Motor inhibition associated with the affordance of briefly displayed objects

Research has demonstrated that left- and right-hand responses are facilitated when they are performed with the hand compatible with the orientation of a viewed object. This suggests that graspable objects automatically activate the motor representations that correspond to their orientation. It has recently been proposed that similar positive stimulus–response compatibility effects (PCE) may turn into negative compatibility effects (NCE) when a prime object is displayed very briefly. These NCEs are suggested to reflect motor inhibition mechanisms—motor activation triggered by briefly viewed objects may be treated by the motor system as unwanted, and thus it is rapidly inhibited. We examined whether the motor activation triggered by the orientation of a task-irrelevant object is similarly inhibited when the object is displayed briefly. In Experiment 1, a NCE was observed between the orientation of an object and the responding hand when the object was displayed for 30 or 70 ms. The effect turned into a PCE when the object was displayed for 370 ms. Experiment 2 confirmed that this motor inhibition effect was produced by the handle affordance of the object rather than some abstract visual properties of the object.     

Implicit response-irrelevant number information triggers the SNARC effect: Evidence using a neural overlap paradigm

There is evidence from the SNARC (spatial–numerical association of response codes) effect and NDE (numerical distance effect) that number activates spatial representations. Most of this evidence comes from tasks with explicit reference to number, whether through presentation of Arabic digits (SNARC) or through magnitude decisions to nonsymbolic representations (NDE). Here, we report four studies that use the neural overlap paradigm developed by Fias, Lauwereyns, and Lammertyn (2001) to examine whether the presentation of implicit and task-irrelevant numerosity information (nonsymbolic arrays and auditory numbers) is enough to activate a spatial representation of number. Participants were presented with either numerosity arrays (1–9 circles or triangles) to which they made colour (Experiment 1) or orientation (Experiment 2) judgements, or auditory numbers coupled with an on-screen stimulus to which they made a colour (Experiment 3) or orientation (Experiment 4) judgement. SNARC effects were observed only for the orientation tasks. Following the logic of Fias et al., we argue that this SNARC effect occurs as a result of overlap in parietal processing for number and orientation judgements irrespective of modality. Furthermore, we found stronger SNARC effects in the small number range (1–4) than in the larger number range (6–9) for both nonsymbolic displays and auditory numbers. These results suggest that quantity is extracted (and interferes with responses in the orientation task) but this is not exact for the entire number range. We discuss a number of alternative models and mechanisms of numerical processing that may account for such effects.     

Timing of in situ visual information pick-up that differentiates expert and near-expert anticipation in a complex motor skill

The timing of visual information pick-up for visual anticipation was examined by comparing the capability of multiple skill groups, expert and near-expert karate athletes and novices, to block attacks using an in situ temporal occlusion paradigm. Participants stood facing a karate opponent and then attempted to block attacks (kicks and punches), whilst their vision of attacks was occluded: (a) prior to onset of opponent motion (O1), (b) after preparatory head movement (O2), and (c) after initiation of the attacking motion (O3). A no occlusion control condition provided complete vision of attacks (O4). Results revealed that expert anticipation was not significantly different to that of near-experts at O1, but was significantly different to the other group across O2–O4. Expert anticipation, however, was significantly above chance across all occlusion conditions, but near-experts performed above chance at O3 and O4, whilst novices were better than chance at O4. Unexpectedly, unique evidence was found that expert anticipation could be differentiated from near-expert anticipation in the earliest occlusion condition, where it was found that only experts were capable of using visual information from a static opponent to anticipate and block attacks above chance. The findings further understanding of expert visual anticipation to guide motor skills beyond existing expert–novice comparisons.     

Native language influence on the distributive effect in producing second language subject–verb agreement

Three experiments were conducted to investigate the distributive effect when producing subject–verb agreement in English as a second language (L2) when the participant's first language either does or does not require subject–verb agreement. Both Chinese–English and Uygur–English bilinguals were included in Experiment 1. Chinese has no required subject–verb agreement, whereas Uygur does. Results showed that the distributive effect was observed in Uygur–English bilinguals but not in Chinese–English bilinguals, indicating that this particular first language (L1) syntactic feature is one significant factor affecting the distributive effect in the production of subject–verb agreement in L2. Experiment 2 further investigated the matter by choosing Chinese–English participants with higher L2 proficiency. Still, no distributive effect was observed, suggesting that the absence of distributive effect in Chinese–English bilinguals in Experiment 1 was not due to low proficiency in the target language. Experiment 3 changed the way the stimuli were presented, highlighting the singular or distributive nature of the subject noun phrases, and the distributive effect was observed in Chinese–English bilinguals. Altogether, the results show that the L1 syntactic feature of subject–verb agreement is one significant factor affecting the distributive effect in the production of subject–verb agreement in L2. More specifically, distributive effects rarely occur in L2 when L1 has no requirement on subject–verb agreement, whereas distributive effects are more likely to occur in L2 when the L1 also has required subject–verb agreement.     

Conversational construction of new meaning configurations in organizational innovation: A generative approach

Abstract

Organizational innovation is approached as a joint conversational event where new configurations of meaning are constructed. The emphasis in this article is on understanding the social dynamic processes of creating new meaning. A perspectivistic approach is developed which looks at how actors speak from their perspectives and give form to the sense-making process through discursive practices. The innovation process is documented, using an interpretive research, in two case studies: the creation of a young high tech firm and the internal development of a manufacturing unit of a multinational corporation. Three theoretical propositions derived from the cases are discussed and interwoven with existing literature: generative characteristics of conversations, the experiential profundity which can be seen as inherently social-relational, and the paradoxical nature of innovation. These propositions are summarized in conceptual charts; their use lies in multiplying and developing them into new ones as new contexts are explored.     

MMPI-2 configurations among victims of bullying at work

Bullying at work, the systematic exposure to psychological violence and harassment in the workplace, places a serious strain on many employees. The aim of this study was to investigate psychological correlates of bullying among former and current victims using the MMPI-2. A total of 85 individuals, recruited among members of two Norwegian associations of bullying victims, participated in the study. Two hypotheses were tested: (1) Bullied victims have an elevated personality profile on the MMPI-2, although different kinds of personality profiles may be distinguished; (2) the personality profiles of the victims are related to the type of behaviour and the intensity of the behaviours experienced by the victim. Both hypotheses were confirmed. The study demonstrated, using cluster analysis, that the sample of bullied victims can be divided into three personality groups (“The seriously affected”, “The disappointed and depressed”, and “The common”.) The elevated 3-2-1 personality profile was most typical. Surprisingly, the victims of the common cluster reported the highest level of exposure to bullying, suggesting a vulnerability factor among the other victims. The scores on the new MMPI-2 Content scales were also analysed. The seriously affected group reported a high level of generalized anxiety, fear of specific incidences, and many health concern worries.