Oscillatory brain dynamics, wavelet analysis, and cognition

On the basis of a systems theoretical approach it was hypothesized that event-related potentials (ERPs) are superpositions of stimulus-evoked and time-locked EEG rhythms reflecting resonance properties of the brain (Ba?ar, 1980). This approach led to frequency analysis of ERPs as a way of analyzing evoked rhythms. The present article outlines the basic features of ERP frequency analysis in comparison to ERP wavelet analysis, a recently introduced method of time-frequency analysis. Both methods were used in an investigation of the functional correlates of evoked rhythms where auditory and visual ERPs were recorded from the cat brain. Intracranial electrodes were located in the primary auditory cortex and in the primary visual cortex thus permitting "cross-modality" experiments. Responses to adequate stimulation (e.g., visual ERP recorded from the visual cortex) were characterized by high amplitude alpha (8-16 Hz) responses which were not observed for inadequate stimulation. This result is interpreted as a hint at a special role of alpha responses in primary sensory processing. The results of frequency analysis and of wavelet analysis were quite similar, with possible advantages of wavelet methods for single-trial analysis. The results of frequency analysis as performed earlier were thus confirmed by wavelet analysis. This supports the view that ERP frequency components correspond to evoked rhythms with a distinct biological significance.     

Change of spatial field effects in 16- to 20-week-old infants

Infants from 16 to 20 weeks were presented with objects moving across a 60-cm distance. Tracking increased between 16 and 18 weeks, reaching increased at 18 weeks, and arm lifts (swipes) showed no age change. A right spatial field bias in tracking disappeared gradually. Swipes occurred most often in front of the object, when it was moving in the center field, presumably as reactions due to spatial proximity. Reaching occurred in the peripheral spatial fields in the younger infants, but in the older infants most often in the center spatial field. Moreover, reaching occurred generally more often toward the left spatial field and predicted the emergence of tracking the left spatial field. Thus, it appeared that a bias in reaching corrected a bias in tracking. Similar effects of limb movements, especially when reaching, were found in the successful treatment of visual neglect patients in neuropsychological research.     

Relative mislocalization of briefly presented stimuli in the retinal periphery

We studied the ability to localize flashed stimuli, using a relative judgment task. When observers are asked to localize the peripheral position of a probe with respect to the midposition of a spatially extended comparison stimulus, they tend to judge the probe as being more toward the periphery than is the midposition of the comparison stimulus. We report seven experiments in which this novel phenomenon was explored. They reveal that the mislocalization occurs only when the probe and the comparison stimulus are presented in succession, independent of whether the probe or the comparison stimulus comes first (Experiment 1). The size of the mislocalization is dependent on the stimulus onset asynchrony (Experiment 2) and on the eccentricity of presentation (Experiment 3). In addition, the illusion also occurs in an absolute judgment task, which links mislocalization with the general tendency to judge peripherally presented stimuli as being more foveal than they actually are (Experiment 4). The last three experiments reveal that relative mislocalization is affected by the amount of spatial extension of the comparison stimulus (Experiment 5) and by its structure (Experiments 6 and 7). This pattern of results allows us to evaluate possible explanations of the illusion and to relate it to comparable tendencies observed in eye movement behavior. It is concluded that the system in charge of the guidance of saccadic eye movements is also the system that provides the metric in perceived visual space.     

Gender differences in a clinical sample of patients with borderline personality disorder

The aim of the study was to investigate gender differences and similarities in patients with borderline personality disorder (BPD) with respect to Axis I comorbidity, Axis II comorbidity, general psychopathology (Symptom Checklist 90-Revised), and dimensional personality traits (NEO-Personality-Inventory Revised [NEO-PI-R] and the Dimensional Assessment of Personality Profile Basic questionnaire [DAPP-BQ]). Fifty-seven men and 114 women with BPD were included in the study. Regarding Axis I and II disorders in an exploratory analysis, men with BPD more often fulfilled the diagnostic criteria for binge eating disorder, antisocial personality disorder, narcissistic personality disorder, and conduct disorder in childhood, whereas women had higher frequencies of bulimia nervosa, posttraumatic stress disorder, and panic disorder with agoraphobia. After correcting for multiple tests, only the gender differences in narcissistic and antisocial personality disorder remained significant. In the SCL-90-R profile, no significant gender differences could be identified. In the exploratory analysis of the dimensional personality traits, women showed higher rates on the NEO-PI-R main factors (Neuroticism and Agreeableness) compared to men. In the DAPP-BQ profile, men reached higher sores on the main factor, Dissocial Behavior. When correcting for multiple tests, gender differences still existed for Neuroticism and Dissocial Behavior. Our results argue for gender differences in Axis I and II comorbidity and dimensional personality traits in BPD. However, in general, more similarities than differences were shown in this study.     

Fehldiagnose Aufmerksamkeitsdefizit- und Hyperaktivit?tssyndrom?

Although it is assumed both by healthcare professionals as well as by public opinion that attention deficit hyperactivity disorder (ADHD) is widely overdiagnosed, so far there is little empirical evidence to support this presumption. However, the presented study shows clear evidence for an overdiagnosis of ADHD. Furthermore, the data demonstrate that based on identical symptoms, boys more often receive a diagnosis for ADHD than girls. A false ADHD diagnosis also correlates with a recommendation for medical and psychotherapeutic treatment. One explanation for misdiagnosis is the fact that therapists in the course of diagnosis, as with other everyday decision-making processes, are influenced by heuristics. The most common heuristics that can lead to misdiagnosis are the representativeness heuristic and the availability heuristic. Such mistakes could be avoided by clearly following diagnostic criteria and the use of structural interviews.     

Military training and personality trait development: does the military make the man, or does the man make the military?

Military experience is an important turning point in a person's life and, consequently, is associated with important life outcomes. Using a large longitudinal sample of German males, we examined whether personality traits played a role during this period. Results indicated that personality traits prospectively predicted the decision to enter the military. People lower in agreeableness, neuroticism, and openness to experience during high school were more likely to enter the military after graduation. In addition, military training was associated with changes in personality. Compared with a control group, military recruits had lower levels of agreeableness after training. These levels persisted 5 years after training, even after participants entered college or the labor market. This study is one of the first to identify life experiences associated with changes in personality traits. Moreover, our results suggest that military experiences may have a long-lasting influence on individual-level characteristics.     

Longitudinal associations of cognitive ability,personality traits and school grades with antisocial behaviour

This study investigated the role of adolescents' cognitive ability, personality traits and school success in predicting later criminal behaviour. Cognitive ability, the five‐factor model personality traits and the school grades of a large sample of Estonian schoolboys (N = 1919) were measured between 2001 and 2005. In 2009, judicial databases were searched to identify participants who had been convicted of misdemeanours or criminal offences. Consistent with previous findings, having a judicial record was associated with lower cognitive ability, grade point average, agreeableness, and conscientiousness and higher neuroticism. In multivariate path models, however, the contributions of cognitive ability and conscientiousness were accounted for by school grades and the effect of neuroticism was also accounted for by other variables, leaving grade point average and agreeableness the only independent predictors of judicial record status. Copyright © 2011 John Wiley & Sons, Ltd.     

Formula: see text]Executive functions in extremely low birth weight and late-preterm preschoolers: Effects on working memory and response inhibition

Executive function (EF) refers to fundamental capacities that underlie more complex cognition and have ecological relevance across the individual's lifespan. However, emerging executive functions have rarely been studied in young preterm children (age 3) whose critical final stages of fetal development are interrupted by their early birth. We administered four novel touch-screen computerized measures of working memory and inhibition to 369 participants born between 2004 and 2006 (52 Extremely Low Birth Weight [ELBW]; 196 late preterm; 121 term-born). ELBW performed worse than term-born on simple and complex working memory and inhibition tasks and had the highest percentage of incomplete performance on a continuous performance test. The latter finding indicates developmental immaturity and the ELBW group's most at-risk preterm status. Additionally, late-preterm participants performed worse compared with term-born on measures of complex working memory but did not differ from those term-born on response inhibition measures. These results are consistent with a recent literature that identifies often subtle but detectable neurocognitive deficits in late-preterm children. Our results support the development and standardization of computerized touch-screen measures to assess EF subcomponent abilities during the formative preschool period. Such measures may be useful to monitor the developmental trajectory of critical executive function abilities in preterm children, and their use is necessary for timely recognition of deficit and application of appropriate interventional strategies.