Neuromagnetic evidence for the timing of lexical activation: an MEG component sensitive to phonotactic probability but not to neighborhood density

Evidence from electrophysiological measures such as ERPs (event-related potentials) and MEG (magnetoencephalography) suggest that the first evoked brain response component sensitive to stimulus properties affecting reaction times in word recognition tasks occurs at 300-400 ms. The present study used the stimulus manipulation of Vitevich and Luce (1999) to investigate whether the M350, an MEG response component peaking at 300-400 ms, reflects lexical or postlexical processing. Stimuli were simultaneously varied in phonotactic probability, which facilitates lexical activation, and in phonological neighborhood density, which inhibits the lexical decision process. The present results indicate that the M350 shows facilitation by phonotactic probability rather than inhibition by neighborhood density. Thus the M350 cannot be a postlexical component.     

African American and Caucasian attempters compared for suicide risk factors: a preliminary study

The aim of the study was to compare African American and Caucasian substance dependent suicide attempters for risk factors for suicidal behavior. One hundred and fifty-eight African American and 95 Caucasian substance dependent patients who had attempted suicide were interviewed and their family history of suicidal behavior recorded. Patients completed the Childhood Trauma Questionnaire, the Eysenck Personality Questionnaire, and the Foulds Hostility and Direction of Hostility Questionnaire. The results revealed that there were no significant differences between the African American and Caucasian suicide attempters for marital status, age, childhood abuse, or for personality scores for neuroticism, extraversion, psychoticism, or hostility. However, the African American attempters had significantly lower childhood emotional neglect scores. Also, significantly more of the Caucasian attempters had a family history of suicide and current legal problems. Further studies seem warranted examining for differences between African Americans and Caucasians for risk factors for suicidal behavior.     

The criterion‐related validity of a short commensurate measure of personality‐based person‐organization fit

Our goal was to develop a commensurate measure of personality‐based person‐organization fit and examine its criterion‐related validity for two retention‐related attitudes: job satisfaction and intention to stay. At T0, 637 employees completed our questionnaire. Two years later, at T1, 171 of the original respondents completed our questionnaire again. Results showed that the organizational personality perceptions are relatively stable. Polynomial regression analyses and surface plots revealed that job satisfaction and intention to stay are higher when there is perfect fit between the person and the organization compared to when the person and the organization differ in traits. However, in most cases, we found the work attitudes to be maximized when both the person and the organization score high on the personality traits.     

Recent Biologic Studies on Suicide

This paper selectively reviews the author's recent studies on suicidal behavior in depression. Data are reviewed from a study of depressed patients who had monoamine metabolites measured in both the cerebrospinal fluid (CSF) and urine. Depressed patients who had attempted suicide had significantly reduced CSF concentrations of the dopamine metabolite homovanillic acid (HVA) and significantly lower urinary outputs of HVA than patients who had not attempted suicide. Similarly, patients who went on to reattempt suicide over a 5-year follow-up period had both significantly reduced CSF concentrations of HVA and lower urinary outputs of HVA than patients who did not reattempt. These data suggest a role for diminished central dopaminergic neurotransmission in suicidal behavior in depression. Patients who had made a violent suicide attempt also showed evidence of dysregulation of the hypothalamic-pituitary-adrenal axis.     

Positional and temporal clustering in serial order memory

The well-known finding that responses in serial recall tend to be clustered around the position of the target item has bolstered positional-coding theories of serial order memory. In the present study, we show that this effect is confounded with another well-known finding—that responses in serial recall tend to also be clustered around the position of the prior recall (temporal clustering). The confound can be alleviated by conditioning each analysis on the positional accuracy of the previously recalled item. The revised analyses show that temporal clustering is much more prevalent in serial recall than is positional clustering. A simple associative chaining model with asymmetric neighboring, remote associations, and a primacy gradient can account for these effects. Using the same parameter values, the model produces reasonable serial position curves and captures the changes in item and order information across study-test trials. In contrast, a prominent positional coding model cannot account for the pattern of clustering uncovered by the new analyses.     

Evidence of fixed capacity in visual object categorization

How is visual object perception limited by divided attention? Whereas some theories have proposed that it is not limited at all (unlimited capacity), others have proposed that divided attention introduces restrictive capacity limitations or serial processing (fixed capacity). We addressed this question using a task in which observers searched for instances of particular object categories, such as a moose or squirrel. We applied an extended simultaneous-sequential paradigm to test the fixed-capacity and unlimited-capacity models (Experiment 1). The results were consistent with fixed capacity and rejected unlimited capacity. We ascertained that these results were due to attention, and not to sensory interactions such as crowding, by repeating the experiment using a cuing paradigm with physically identical displays (Experiment 2). The results from both experiments were consistent with theories of object perception that have fixed capacity, and they rejected theories with unlimited capacity. Both serial and parallel models with fixed capacity remain viable alternatives.     

Happy guys finish last: the impact of emotion expressions on sexual attraction

This research examined the relative sexual attractiveness of individuals showing emotion expressions of happiness, pride, and shame compared with a neutral control. Across two studies using different images and samples ranging broadly in age (total N = 1041), a large gender difference emerged in the sexual attractiveness of happy displays: happiness was the most attractive female emotion expression, and one of the least attractive in males. In contrast, pride showed the reverse pattern; it was the most attractive male expression, and one of the least attractive in women. Shame displays were relatively attractive in both genders, and, among younger adult women viewers, male shame was more attractive than male happiness, and not substantially less than male pride. Effects were largely consistent with evolutionary and socio-cultural-norm accounts. Overall, this research provides the first evidence that distinct emotion expressions have divergent effects on sexual attractiveness, which vary by gender but largely hold across age.