Familiarity from orthographic information: Extensions of the recognition without identification effect

Two experiments were conducted to investigate the effect of letter location information in recognition memory judgments. The experiments used the recognition without identification paradigm (Peynircioglu, 1990), in which participants first attempt to identify the test item and then make a recognition decision as to whether or not the item was studied. In these studies, items that are not identified but that correspond to items that were presented are typically still rated as more likely to have been studied than those that were not presented. The present experiments demonstrated this finding with a variant of the conjunction lure paradigm. In Experiments 1 and 2, participants were tested with word fragments that were made from the letters of two words. When the letters were from studied items, fragments were rated higher than when the test items were derived from two unstudied items, or one studied item and one unstudied item, suggesting that recognition without identification is prone to the same types of errors as recognition with identification. Results are discussed in terms of familiarity effects in recognition memory.     

Learning and memory deficits in mice lacking protease activated receptor-1

The roles of serine proteases and protease activated receptors have been extensively studied in coagulation, wound healing, inflammation, and neurodegeneration. More recently, serine proteases have been suggested to influence synaptic plasticity. In this context, we examined the role of protease activated receptor 1 (PAR1), which is activated following proteolytic cleavage by thrombin and plasmin, in emotionally motivated learning. We were particularly interested in PAR1 because its activation enhances the function of NMDA receptors, which are required for some forms of synaptic plasticity. We examined several baseline behavioral measures, including locomotor activity, expression of anxiety-like behavior, motor task acquisition, nociceptive responses, and startle responses in C57Bl/6 mice in which the PAR1 receptor has been genetically deleted. In addition, we evaluated learning and memory in these mice using two memory tasks, passive avoidance and cued fear-conditioning. Whereas locomotion, pain response, startle, and measures of baseline anxiety were largely unaffected by PAR1 removal, PAR1-/- animals showed significant deficits in a passive avoidance task and in cued fear conditioning. These data suggest that PAR1 may play an important role in emotionally motivated learning.     

The ethics of biometrics: the risk of social exclusion from the widespread use of electronic identification

Discussions about biotechnology tend to assume that it is something to do with genetics or manipulating biological processes in some way. However, the field of biometrics-the measurement of physical characteristics-is also biotechnology and is likely to affect the lives of more people more quickly than any other form. The possibility of social exclusion resulting from the use of biometrics data for such uses as identity cards has not yet been fully explored. Social exclusion is unethical, as it unfairly discriminates against individuals or classes of people. Social exclusion is unethical, as it unfairly discriminates against individuals or classes of people. This article looks at some of the ways in which social exclusion might arise from the use of biometric data, and introduces a model of balancing individual interests with which to analyse whether it is justified to run the risk of excluding some members of society for the benefit of others.     

Speech-associated gestures, Broca's area, and the human mirror system

Speech-associated gestures are hand and arm movements that not only convey semantic information to listeners but are themselves actions. Broca's area has been assumed to play an important role both in semantic retrieval or selection (as part of a language comprehension system) and in action recognition (as part of a "mirror" or "observation-execution matching" system). We asked whether the role that Broca's area plays in processing speech-associated gestures is consistent with the semantic retrieval/selection account (predicting relatively weak interactions between Broca's area and other cortical areas because the meaningful information that speech-associated gestures convey reduces semantic ambiguity and thus reduces the need for semantic retrieval/selection) or the action recognition account (predicting strong interactions between Broca's area and other cortical areas because speech-associated gestures are goal-direct actions that are "mirrored"). We compared the functional connectivity of Broca's area with other cortical areas when participants listened to stories while watching meaningful speech-associated gestures, speech-irrelevant self-grooming hand movements, or no hand movements. A network analysis of neuroimaging data showed that interactions involving Broca's area and other cortical areas were weakest when spoken language was accompanied by meaningful speech-associated gestures, and strongest when spoken language was accompanied by self-grooming hand movements or by no hand movements at all. Results are discussed with respect to the role that the human mirror system plays in processing speech-associated movements.     

Self-monitoring and mimicry of positive and negative social behaviors

This study examined the role that self-monitoring plays in behavioral mimicry. Participants were exposed to videotaped targets who were laughing, yawning, frowning, or neutral in their expression. Participants’ behavioral mimicry while viewing the targets was recorded. It was hypothesized that higher self-monitors would show greater mimicry than lower self-monitors. It was also hypothesized that participants would respond differently to positive and negative target expressions. Participants who scored higher in self-monitoring did mimic the targets’ behaviors more often, and participants showed less mimicry of frowns than of laughs or yawns.     

Walking patterns change rapidly following asymmetrical lower extremity loading

The purpose of this study was to determine the amount of time needed for individuals to become well accommodated to asymmetrical changes in lower extremity inertial properties. Participants walked at 1.57 m s(-1) during four separate data collection sessions over the period of eight days. On days 1 and 7, participants completed a 60 min treadmill protocol consisting of both overground (motion and ground reaction force recorded) and treadmill (vertical ground reaction force recorded) walking. On day 1, 1.95 kg was attached distally to one shank prior to the start of the 60 min treadmill protocol and was not removed until day 7. On day 7, the load was permanently removed prior to the 60 min treadmill protocol. On days 2 and 8 participants completed three overground walking trials and walked on the treadmill for approximately 5 min. Stance and swing time asymmetries appeared immediately and were complete following initial assessment after the load was attached. Net joint moments at the knee and hip were altered and continued to change beyond initial exposure to the load, but these changes were complete within 5 min. Overall, results suggest that changes in walking symmetry due to asymmetrical lower extremity loading are immediate and complete within 5 min of exposure to the load. We recommend that at least 5 min of walking or other normal activity be used to accommodate individuals to novel asymmetrical lower extremity loading.     

Tracking unique objects

Is content addressable in the representation that subserves performance in multiple-object-tracking (MOT) experiments? We devised an MOT variant that featured unique, nameable objects (cartoon animals) as stimuli. There were two possible response modes: standard, in which observers were asked to report the locations of all target items, and specific, in which observers had to report the location of a particular object (e.g., "Where is the zebra?"). A measure of capacity derived from accuracy allowed for comparisons of the results between conditions. We found that capacity in the specific condition (1.4 to 2.6 items across several experiments) was always reliably lower than capacity in the standard condition (2.3 to 3.4 items). Observers could locate specific objects, indicating a content-addressable representation. However, capacity differences between conditions, as well as differing responses to the experimental manipulations, suggest that there may be two separate systems involved in tracking, one carrying only positional information, and one carrying identity information as well.     

Trait expectancies and stereotype expectancies have the same effect on person memory

Two studies examined whether trait expectancies and stereotype expectancies similarly affected memory for expectancy-relevant behaviors. The results of both studies showed that, when activated in identical ways, trait expectancies and stereotype expectancies had similar effects on recall. Better recall was obtained for expectancy-incongruent items when expectancies were activated in relatively overt ways, while better recall for expectancy-congruent items was obtained when expectancies were activated in less overt ways. Additional analyses examining the order of events that emerged in the recall protocols provided little evidence that participants attempted to reconcile the items, as would be predicted by some earlier models of person memory (e.g., Srull, 1981). The implications of these findings for how social expectancies guide social information processing are discussed.     

Understanding the social costs of narcissism: the case of the tragedy of the commons

Two studies examined narcissism and behavior in a commons dilemma. Study 1 used a four-person, laboratory-based task and Study 2 used a dyadic task. Participants were told that they represented one of four (Study 1) or two (Study 2) forestry companies and then were asked to harvest timber from a renewable forest. Narcissism was found to be positively related to acquisitive goals and harvesting more timber in the initial round. The more narcissists harvesting in the competitive group of four (Study 1) or dyad (Study 2), the less timber was harvested overall and the more rapidly the forest was depleted. Within competitive groups and dyads, however, narcissists harvested more than the nonnarcissists competing with them. In all, narcissism provided a benefit to the self, but at a long-term cost to other individuals and to the commons.