Event-related potentials indicate different processes to mediate categorical and associative priming in person recognition

Whether representations of people are stored in associative networks based on co-occurrence or are stored in terms of more abstract semantic categories is a controversial question. In the present study, participants performed fame decisions to unfamiliar or famous target faces (Experiment 1) or names (Experiment 2), which were primed, either by highly associated celebrity names or by names from the same occupational category, or were unprimed. Reaction times and event-related potentials (ERPs) were recorded. Reaction times yielded significant priming effects for both associated and same category conditions. ERPs to targets in the associated condition were significantly more positive than were ERPs in all other conditions over central and parietal areas (300-600 ms; N400 priming effect). By contrast, a more posterior effect was found for categorical priming. These findings held for both cross-domain (Experiment 1) and within-domain conditions (Experiment 2). Results (a) demonstrate behavioral and ERP evidence for categorical priming in person recognition, consistent with the assumption that shared semantic information units can mediate semantic priming, and (b) suggest that associative and categorical priming are based on mechanisms that are at least partially different.     

The link between speech perception and production is phonological and abstract: evidence from the shadowing task

This study reports a shadowing experiment, in which one has to repeat a speech stimulus as fast as possible. We tested claims about a direct link between perception and production based on speech gestures, and obtained two types of counterevidence. First, shadowing is not slowed down by a gestural mismatch between stimulus and response. Second, phonetic detail is more likely to be imitated in a shadowing task if it is phonologically relevant. This is consistent with the idea that speech perception and speech production are only loosely coupled, on an abstract phonological level.     

Recalibrating color categories using world knowledge

ABSTRACT— When the perceptual system uses color to facilitate object recognition, it must solve the color-constancy problem: The light an object reflects to an observer's eyes confounds properties of the source of the illumination with the surface reflectance of the object. Information from the visual scene ( bottom-up information) is insufficient to solve this problem. We show that observers use world knowledge about objects and their prototypical colors as a source of top-down information to improve color constancy. Specifically, observers use world knowledge to recalibrate their color categories. Our results also suggest that similar effects previously observed in language perception are the consequence of a general perceptual process.     

Contrasting effects of motor and visual spatial learning tasks on dendritic arborization and spine density in rats

Rats were trained in four different learning tasks including the Morris-water task, a T-maze delayed nonmatch-to-sample task, a skilled unilateral reaching task, and a skilled bilateral string-pulling task. At the end of training the brains were harvested and stained using a Golgi-Cox procedure. Learning the spatial navigation task produced increased dendritic length and branching as well as decreased spine density in layer III pyramidal cells in occipital cortex. Learning the T-maze task increased dendritic branching in layer III medial but not orbital frontal cortex pyramidal cells and increased spine density in both regions. The motor learning tasks produced increased dendritic length and branching in layer V pyramidal cells in the forelimb cortex in the hemisphere contralateral to the trained limb in the unilateral skilled reaching task and in both limbs in the bilateral skilled pulling task. There were no changes in spine density in layer V in the motor tasks, but there was a decrease in spine density in layer III in the unilateral reaching task. Spatial and motor learning thus produce different patterns of change in layer III cortical pyramidal neurons. Furthermore, changes in spine density and dendritic length and branching are not tightly correlated and can increase and/or decrease independently of one another in learning tasks.     

Rapid-REM: A MATLAB simulator of the replaced-elements model

A recent proposal for an elemental account of associative learning phenomena is the replaced-elements model (REM) put forward by Wagner (2003). Although the ideas underlying this model are comparatively simple, implementation of the model is rather complex. In this article, we present Rapid-REM, a MATLAB simulator of Wagner's model. Rapid-REM features a graphical user interface for manipulating all essential parameter values and for control of the simulation process, graphical visualization of the simulation course and the results, and the alternative possibility of simulating the replaced-elements model as it was originally proposed (Wagner & Brandon, 2001). Rapid-REM is available free of charge from www.staff.uni-marburg.de/(tilde)lachnit/Rapid-REM/. This simulator makes it easy to derive predictions for REM and evaluate them, and it will therefore facilitate insights into the mechanisms of associative learning.     

Regulatory fit as a determinant of sport performance: How to succeed in a soccer penalty-shooting

ObjectivesAccording to regulatory focus theory, goal pursuit can be achieved by either keeping a promotion or a prevention focus [Higgins, E. T. (1997). Beyond pleasure and pain. American Psychologist, 52, 1280–1300; Higgins, E. T. (2000). Making a good decision: value from fit. American Psychologist, 55, 1217–1230]. Moreover, it has been assumed that people experience fit when they pursue a goal in a manner that sustains their chronic orientation and that fit has a positive impact on performance. In two studies, we investigated the significance of regulatory focus and fit in the realm of sports performance, such as the success rate in a soccer penalty-shooting task.Methods and ResultsIn a pilot study, we assessed the chronic regulatory orientation of 211 athletes from different sports. Among others, we found more promotion focus with attackers than with defenders. In the main study, we assessed the chronic regulatory orientation of 20 soccer players who took part in a penalty-shooting task. For half of them, the task was described in terms of promotion, for the others in terms of prevention. We found a positive impact of regulatory fit on scoring performance.ConclusionsOur findings demonstrate a great potential of regulatory focus theory for the understanding and enhancement of sport performance. The assessment of athletes' chronic regulatory orientation could be of importance for the selection of athletes, the adjustment of tactics and strategies, and coaches' framing of instructions.     

Computer-Based Performance Monitoring and Productivity in a Multiple Task Environment

Computer-based performance monitoring (CPM) provides managers with the ability to continuously, and unobtrusively, monitor the work performed by their employees. This paper examines the impact that CPM has on productivity when people are monitored on only a portion of the work that they perform. In a simulated work setting, subjects worked on two computerized tasks, and were led to believe that their work on one, both, or none of the tasks would be electronically monitored. People who were monitored only on a relatively simple task tended to work at a faster rate on both their monitored and non-monitored tasks, in comparison to people who were not monitored at all. People who were monitored only on a task that was more moderate in level of difficulty did not work any faster or more accurately than people who were not monitored. The results of the current study suggests that under certain conditions, employees may not discriminate between monitored and non-monitored work. Recommendations are offered to managers who are considering implementing CPM in their workplace.