A medication screening tool for cognitive aging researchers

A Web-based medication screening tool that provides researchers with information about side effects associated with medications commonly used by older participants is described. This tool can be used for research purposes to better separate the effects of normal, healthy aging processes from the deleterious effects often associated with medication usage. Researchers can use this tool, called SMART (Screening Medications: Aging Research Taxonomy), to (a) obtain information pertaining to the cognitive, sensory, and motor side effects associated with specific medications and (b) screen medications in their research for side effect severity. The Web address for the tool is www.psychology.gatech.edu/SMART     

A Note on the Speed-Amplitude Function in Movement Control

An experiment is reported that documents the maximum average speed-amplitude relationship across the full range of motion for elbow flexion. Minimum movement time increased as a negative exponential within the movement range up to 94-97% of the maximum range of motion. At this point a discontinuity occurred with movement time increasing at an increasing rate probably due to anatomical and morphological constraints. These results suggest that the maximum average velocity-amplitude boundary to the movement speed-accuracy relationship is curvilinear. Kinematic analysis of the movements as a function of range of motion suggests that a simple pulse-step model of movement control cannot account for the present findings.     

An application of caricature: How to improve the recognition of facial composites

Facial caricatures exaggerate the distinctive features of a face and may elevate the recognition of a familiar face. We investigate whether the recognition of facial composites, or pictures of criminal faces, could be similarly enhanced. In this study, participants first estimated the degree of caricature necessary to make composites most identifiable. Contrary to expectation, an anticaricature was found to be best, presumably as this tended to reduce the appearance of errors. In support of this explanation, more positive caricature estimates were assigned to morphed composites: representations that tend to contain less overall error. In addition, anticaricaturing reduced identification for morphed composites but enhanced identification for individual composites. Although such improvements were too small to be of value to law enforcement, a sizeable naming benefit was observed when presenting a range of caricature states, which appeared to capitalize on individual differences in the internal representation of familiar faces.     

Recovering faces from memory: the distracting influence of external facial features

Recognition memory for unfamiliar faces is facilitated when contextual cues (e.g., head pose, background environment, hair and clothing) are consistent between study and test. By contrast, inconsistencies in external features, especially hair, promote errors in unfamiliar face-matching tasks. For the construction of facial composites, as carried out by witnesses and victims of crime, the role of external features (hair, ears, and neck) is less clear, although research does suggest their involvement. Here, over three experiments, we investigate the impact of external features for recovering facial memories using a modern, recognition-based composite system, EvoFIT. Participant-constructors inspected an unfamiliar target face and, one day later, repeatedly selected items from arrays of whole faces, with "breeding," to "evolve" a composite with EvoFIT; further participants (evaluators) named the resulting composites. In Experiment 1, the important internal-features (eyes, brows, nose, and mouth) were constructed more identifiably when the visual presence of external features was decreased by Gaussian blur during construction: higher blur yielded more identifiable internal-features. In Experiment 2, increasing the visible extent of external features (to match the target's) in the presented face-arrays also improved internal-features quality, although less so than when external features were masked throughout construction. Experiment 3 demonstrated that masking external-features promoted substantially more identifiable images than using the previous method of blurring external-features. Overall, the research indicates that external features are a distractive rather than a beneficial cue for face construction; the results also provide a much better method to construct composites, one that should dramatically increase identification of offenders.     

Social Identification and Interpersonal Communication in Computer‐Mediated Communication: What You Do Versus Who You Are in Virtual Groups

This study investigates the influence of interpersonal communication and intergroup identification on members’ evaluations of computer‐mediated groups. Participants (N= 256) in 64 four‐person groups interacted through synchronous computer chat. Subgroup assignments to minimal groups instilled significantly greater in‐group versus out‐group identification. One member in each group was instructed to exhibit interpersonally likable or dislikable behavior. Analysis revealed that confederates acting likably were more attractive than those acting dislikably regardless of their in‐group or out‐group status. Further results indicated that interpersonal behavior interacted with subgroup membership on identification shifts following online discussions. Interpersonal dynamics generally provided stronger effects on members in virtual groups than did intergroup dynamics, in contrast to predictions from previous applications of social identification to computer‐mediated communication.