Re-exposure to studied items at test does not influence false recognition

In two experiments, we investigated whether re-exposure to previously studied items at test affects false recognition in the DRM paradigm. Furthermore, we examined whether exposure to the critical lure at test influences memory for subsequently presented study items. In Experiment 1, immediately following each studied DRM list, participants were given a recognition test. The tests were constructed such that the number of studied items preceding the critical lure varied from zero to five. Neither false recognition for critical lures nor accurate memory for studied items was affected by this manipulation. In Experiment 2, we replicated this pattern of results under speeded conditions at test. Both experiments confirm that exposure to previously studied items at test does not affect true or false recognition in the DRM paradigm. This pattern strongly suggests that retrieval processes do not influence false recognition in the DRM paradigm.     

Dopaminergic modulation of the persistence of one-trial hippocampus-dependent memory

The persistence of new memory traces in the hippocampus, encoded following appropriate activation of glutamatergic receptors and the induction of synaptic plasticity, can be influenced by heterosynaptic activation of neuromodulatory brain systems. We therefore investigated the effects of a hippocampus-specific blockade of dopamine D1/D5 receptors on the persistence of spatial memory encoded in one trial using a delayed matching-to-place (DMP) task in a watermaze in which rats learn a new escape location each day. A within-subjects design was used such that both short (20 min) and long (6 h) retention intervals, and both drug (SCH23390, a D1/D5 receptor antagonist) and vehicle (aCSF) infusions were tested on different days in the same animals. Bilateral intrahippocampal infusion of SCH23390 (5 microg in 1 microL per side) prior to trial 1 (encoding) caused a differential impairment as a function of memory delay-with no effect during trial 2 (memory retrieval) after a 20-min interval, but a block of memory at 6 h. Further experiments revealed that infusion of SCH23390 immediately after trial 1 had no effect on retention 6 h later, and the poor memory seen at long retention intervals when the drug was present at encoding was not due to a state-dependent failure of retrieval. These results suggest that activation of D1/D5 receptors during memory encoding is necessary for the formation of a persistent memory trace in the hippocampus. The complementary effects of D1/D5 receptor blockade on the persistence of LTP and the duration of memory are consistent with the idea that changes in synaptic strength underlie memory.     

An examination of the psychometric properties of the Rosenberg Self-Esteem Scale (RSES) in Chinese acute coronary syndrome (ACS) patients

The psychometric properties of the Rosenberg Self-Esteem Scale (RSES) as a clinical research instrument for acute coronary syndrome (ACS) patients were investigated in a translated Chinese version of the instrument. A confirmatory factor analysis was conducted on the RSES to establish its psychometric properties in 128 ACS patients over two observation points (within 1 week and 6 months post-admission for ACS). Internal and test-retest reliability of the RSES-TOT (all-items) and RSES-POS sub-scale (positively valenced items) were found to be acceptable. The RSES-NEG sub-scale (negatively valenced items) lacked acceptable internal reliability. The underlying factor structure of the RSES comprised two distinct but related factors, though there was inconsistency in best model fit indices at the 1-week observation point. The use of the RSES as two sub-scales (RSES-POS and RSES-NEG) may be clinically useful in evaluating the influence of this important psychological construct on the health outcomes of patients with ACS. Directions for future research are indicated.     

Factor structure and use of the hospital anxiety and depression scale in the homeless and socially marginalized

The homeless have been identified as a group at risk of significant anxiety and depression and screening is therefore highly desirable to identify those needing psychological and psychiatric support. However, the psychometric properties of routine screening instruments have yet to be established in this group. This study sought to determine the psychometric properties of the widely used Hospital Anxiety and Depression Scale in this group. Using a cross-sectional design, 314 clients presenting at homelessness units (shelters) supported by The Salvation Army were administered the HADS. Confirmatory factor analysis revealed three-factor models offered the best fit to the data (best-fit model CFI = .98, RMSEA = .06, WRMR = .87). This investigation confirms contemporary research findings that the HADS comprises an underlying tri-dimensional factor structure. However, the internal consistency of the HADS anxiety (alpha = .81) and depression (alpha = .90) sub-scales was excellent. The findings of the current study suggest that the HADS is a suitable screening tool in this group.     

Psychometric properties of the 12-item General Health Questionnaire (GHQ-12) in Chinese women during pregnancy and in the postnatal period

The GHQ-12 is a widely used instrument designed to screen for psychological disturbance (defined as the inability to carry out normal psychological functions and/or the emergence of new distressing phenomena), in a wide variety of clinical groups. The Chinese version of the GHQ-12 is widely used in Hong Kong to screen women during pregnancy and in the postnatal period. The underlying factor structure of the GHQ-12 has been extensively investigated and there is strong evidence to suggest that the instrument is multi-dimensional. The current investigation explored the psychometric properties of this instrument using confirmatory factor analysis, logistic regression and reliability analysis in Chinese women during the third trimester of pregnancy and in the postnatal period. Two- and three-factor models offered superior fit to the data compared to the presumed uni-dimensional structure. However, a four-item sub-scale from an eight-item two-factor model was found to be a significant antenatal predictor of postnatal GHQ-12 assessed caseness. Further evaluation of the clinical utility of this specific two-factor model is recommended.     

Sources of openness/intellect: cognitive and neuropsychological correlates of the fifth factor of personality

We characterize Openness/Intellect as motivated cognitive flexibility, or cognitive exploration, and develop a neuropsychological model relating it to dopaminergic function and to the functions of the prefrontal cortex (PFC). Evidence is reviewed for sources of Openness/Intellect shared with Extraversion and sources unique to Openness/Intellect. The hypothesis that the cognitive functions of the dorsolateral PFC are among the latter was tested using standard measures of cognitive ability and a battery of tasks associated with dorsolateral PFC function (N=175). Dorsolateral PFC function, as well as both fluid and crystallized cognitive ability, was positively related to Openness/Intellect but no other personality trait. Additionally, facet level analysis supported the characterization of Openness/Intellect as a primarily cognitive trait.     

Eyewitness decisions in simultaneous and sequential lineups: A dual-process signal detection theory analysis

Many eyewitness researchers have argued for the application of a sequential alternative to the traditional simultaneous lineup, given its role in decreasing false identifications of innocent suspects (sequential superiority effect). However, Ebbesen and Flowe (2002) have recently noted that sequential lineups may merely bring about a shift in response criterion, having no effect on discrimination accuracy. We explored this claim, using a method that allows signal detection theory measures to be collected from eyewitnesses. In three experiments, lineup type was factorially combined with conditions expected to influence response criterion and/or discrimination accuracy. Results were consistent with signal detection theory predictions, including that of a conservative criterion shift with the sequential presentation of lineups. In a fourth experiment, we explored the phenomenological basis for the criterion shift, using the remember-know-guess procedure. In accord with previous research, the criterion shift in sequential lineups was associated with a reduction in familiarity-based responding. It is proposed that the relative similarity between lineup members may create a context in which fluency-based processing is facilitated to a greater extent when lineup members are presented simultaneously.     

"Economic man" in cross-cultural perspective: behavioral experiments in 15 small-scale societies

Researchers from across the social sciences have found consistent deviations from the predictions of the canonical model of self-interest in hundreds of experiments from around the world. This research, however, cannot determine whether the uniformity results from universal patterns of human behavior or from the limited cultural variation available among the university students used in virtually all prior experimental work. To address this, we undertook a cross-cultural study of behavior in ultimatum, public goods, and dictator games in a range of small-scale societies exhibiting a wide variety of economic and cultural conditions. We found, first, that the canonical model - based on self-interest - fails in all of the societies studied. Second, our data reveal substantially more behavioral variability across social groups than has been found in previous research. Third, group-level differences in economic organization and the structure of social interactions explain a substantial portion of the behavioral variation across societies: the higher the degree of market integration and the higher the payoffs to cooperation in everyday life, the greater the level of prosociality expressed in experimental games. Fourth, the available individual-level economic and demographic variables do not consistently explain game behavior, either within or across groups. Fifth, in many cases experimental play appears to reflect the common interactional patterns of everyday life.     

Contrast configuration influences grouping in apparent motion

We investigated whether the same principles that influence grouping in static displays also influence grouping in apparent motion. Using the Ternus display, we found that the proportion of group motion reports was influenced by changes in contrast configuration. Subjects made judgments of completion of these same configurations in a static display. Generally, contrast configurations that induced a high proportion of group motion responses were judged as more 'complete' in static displays. Using a stereo display, we then tested whether stereo information and T-junction information were critical for this increase in group motion. Perceived grouping was consistently higher for same contrast polarity configurations than for opposite contrast polarity configurations, regardless of the presence of stereo information or explicit T-junctions. Thus, while grouping in static and moving displays showed a similar dependence on contrast configuration, motion grouping showed little dependence on stereo or T-junction information.