Observers can voluntarily shift their psychometric functions without losing sensitivity

Psychometric sensory discrimination functions are usually modeled by cumulative Gaussian functions with just two parameters, their central tendency (μ) and their slope (1/σ). These correspond to Fechner's "constant" and "variable" errors, respectively. Fechner pointed out that even the constant error could vary over space and time and could masquerade as variable error. We wondered whether observers could deliberately introduce a constant error into their performance without loss of precision. In three-dot vernier and bisection tasks with the method of single stimuli, observers were instructed to favour one of the two responses when unsure of their answer. The slope of the resulting psychometric function was not significantly changed, despite a significant change in central tendency. Similar results were obtained when altered feedback was used to induce bias. We inferred that observers can adopt artificial response criteria without any significant increase in criterion fluctuation. These findings have implications for some studies that have measured perceptual "illusions" by shifts in the psychometric functions of sophisticated observers.     

False feedback increases detection of low-prevalence targets in visual search

Many critical search tasks, such as airport and medical screening, involve searching for targets that are rarely present. These low-prevalence targets are associated with extremely high miss rates Wolfe, Horowitz, & Kenner (Nature, 435, 439?C440, 2005). The inflated miss rates are caused by a criterion shift, likely due to observers attempting to equate the numbers of misses and false alarms. This equalizing strategy results in a neutral criterion at 50?% target prevalence, but leads to a higher proportion of misses for low-prevalence targets. In the present study, we manipulated participants?? perceived number of misses through explicit false feedback. As predicted, the participants in the false-feedback condition committed a higher number of false alarms due to a shifted criterion. Importantly, the participants in this condition were also more successful in detecting targets. These results highlight the importance of perceived prevalence in target search tasks.     

How semantic categorization influences inhibitory processing in middle-childhood: an Event Related Potentials study

Throughout middle-childhood, inhibitory processes, which underlie many higher order cognitive tasks, are developing. Little is known about how inhibitory processes change as a task becomes conceptually more difficult during these important years. In adults, as Go/NoGo tasks become more difficult there is a systematic decrease in the P3NoGo response, indicating the use of effective inhibitory strategies (Maguire et al., 2009). This paper investigates the age at which children employ similar inhibitory strategies by studying behavioral and Event Related Potential (ERP) measures of response inhibition for three Go/NoGo tasks. Seventeen 7-8 year-olds and twenty 10-11-year-olds completed three Go/NoGo tasks that differed in the level of categorization necessary to respond. Both age groups displayed slower reaction times as the tasks became more difficult. Further, both groups displayed the predicted Go vs. NoGo P3 amplitude differences in the two simplest tasks, but no significant P3 differences for the most complex task. The reason for this pattern of responses was different in the different age groups. Similar to adults in previous work, the oldest children showed an attenuation of the P3 NoGo response with task difficulty, and no corresponding changes in the Go amplitude. The younger children displayed the opposite pattern, a significant increase in the Go amplitude with task difficulty, and no changes in the NoGo response. These response patterns indicate that efficient inhibitory strategies are developing throughout middle-childhood.     

Interpersonal competence across domains: relevance to personality pathology

Interpersonal problems are significant markers of personality disorders (PDs). There is little research examining the specific interpersonal problems which lead to social impairment in PD. This study used canonical correlation analyses to examine the relationship between interpersonal competence and PDs, first as categorized by DSM-IV diagnoses, then as categorized by empirically-derived factors, in a sample at risk for recurrence of major depression. The most significant sources of shared variance were social inhibition and self-disclosure competence. The empirically-derived PD categories accounted for more variance in interpersonal competence than the DSM-IV diagnostic categories. Social skills training in initiation and self-disclosure may be useful for treating individuals with PD who experience interpersonal problems. Empirically-derived categories of PD symptoms may capture interpersonal problems experienced by individuals with PD which DSM-IV categories do not.     

The Relationship Between Personality and Marital Adjustment Among Distressed Married Couples Seen in Intensive Marital Therapy: An Actor-Partner Interdependence Model Analysis

In this study, the actor-partner interdependence model was utilized to investigate the impact that personality has on marital adjustment in a sample of 270 couples (N = 540) in marital distress that presented to an intensive outpatient marital therapy program. Sixteen Personality Factor Fifth Edition (16PF Fifth Edition) scores revealed significant personality differences between husbands and wives, as well as significant actor and partner effects, suggesting that certain personality traits of one partner predict his or her own, as well as his or her spouse’s, marital adjustment. Gender effects also were evident among the sample, suggesting that a number of personality correlates of marital adjustment tended to be different for the husbands and wives in this study.     

An examination of the Validity of the Elemental Psychopathy Assessment: Relations with Other Psychopathy Measures,Aggression, and Externalizing Behaviors

The Elemental Psychopathy Assessment (EPA) is a new self-report measure of psychopathy designed to assess the personality traits associated with psychopathy from a Five Factor Model perspective. The current study examined the validity of the EPA in sample of undergraduates by examining the relations between the EPA scales and three validated self-report psychopathy instruments, as well as assessments of aggression, substance use, and antisocial behavior. The EPA scales manifested strong convergent validity with the extant psychopathy measures and an expected pattern of relations with measures of externalizing behaviors. Overall, the EPA appears to be a promising measure of psychopathy which provides new opportunities to explore the underlying structure of this construct and parse its relations with constructs central to its nomological network.     

The effects of post-encoding stress on recognition memory: examining the impact of skydiving in young men and women

Prior studies have indicated that post-encoding stress can protect memories from the effects of forgetting, and this has been taken as evidence that stress facilitates memory consolidation. However, it is not known whether stress acts by directly influencing the strength of the underlying memories or whether it influences the generation process that plays a critical role in tests such as free recall. To address this issue, we examined the effects of stress produced by skydiving on recognition memory for negative and neutral pictures. Relative to a non-stress control condition, post-encoding stress in males was found to increase recognition memory for neutral pictures. However, stress was not found to improve recognition for emotional pictures, nor was it found to influence recognition memory in female participants. Additional analysis of recognition performance suggested that stress increased familiarity-based recognition rather than recollection. This study indicates that stress can improve familiarity-based recognition, thus showing that stress directly increases the strength of the underlying memories.     

A five-factor measure of schizotypal personality traits

The current study provides convergent, discriminant, and incremental validity data for a new measure of schizotypy from the perspective of the five-factor model (FFM) of general personality structure. Nine schizotypy scales were constructed as maladaptive variants of respective facets of the FFM (e.g., Aberrant Ideas as a maladaptive variant of FFM Openness to Ideas). On the basis of data from 143 undergraduates, the convergent validity of these nine scales was tested with respect to seven established measures of schizotypy and the respective facets of the FFM. Discriminant validity was tested with respect to facets from other FFM domains and components of schizotypy. Incremental validity was tested with respect to the ability of the FFM schizotypy scales to account for variance in two established measures of schizotypy, after variance accounted for by respective FFM facets and other established measures of schizotypy were first removed. The findings support the validity of these new scales as measures of schizotypal traits and as maladaptive variants of the FFM.