Prevalence,and intellectual outcome of unilateral focal cortical brain damage as a function of age,sex and aetiology

Neurologists and neuropsychologists are aware that aging men are more at risk than women for brain damage, principally because of the well known male-predominant risk for cardiovascular disease and related cerebrovascular accidents. However, a disproportion in prevalence of brain damage between the sexes in childhood may be less suspected. Furthermore, sex-specific risk for other aetiologies of brain damage may be little known, whether in the pediatric or adult populations. Proposals of a sex difference in cognitive recovery from brain damage have also been controversial. Six hundred and thirty five "consecutive" cases with cortical focal lesions including cases of all ages and both sexes were reviewed. Aetiology of the lesion was determined for each case as was postlesion IQ. Risk was highly male prevalent in all age groups, with a predominance of cardiovascular aetiology explaining much of the adult male prevalence. However, several other aetiological categories were significantly male prevalent in juveniles (mitotic, traumatic, dysplasic) and adults (mitotic, traumatic). There was no sex difference in outcome (i.e., postlesion IQ) of these cortical brain lesions for the cohort as a whole, after statistical removal of the influence of lesion extent, aetiology and presence of epilepsy. Mechanisms potentially responsible for sex differences in prevalence, aetiology of brain damage, and recovery, are reviewed and discussed.     

The Nature and Organization of Individual Differences in Executive Functions: Four General Conclusions

Executive functions (EFs)-a set of general-purpose control processes that regulate one's thoughts and behaviors-have become a popular research topic lately and have been studied in many subdisciplines of psychological science. This article summarizes the EF research that our group has conducted to understand the nature of individual differences in EFs and their cognitive and biological underpinnings. In the context of a new theoretical framework that we have been developing (the unity/diversity framework), we describe four general conclusions that have emerged from our research. Specifically, we argue that individual differences in EFs, as measured with simple laboratory tasks, (1) show both unity and diversity (different EFs are correlated yet separable); (2) reflect substantial genetic contributions; (3) are related to various clinically and societally important phenomena; and (4) show some developmental stability.     

Differences in neuronal activity explain differences in memory forming abilities of different populations of Lymnaea stagnalis

The ability to learn and form long-term memory (LTM) can enhance an animal's fitness, for example, by allowing them to remember predators, food sources or conspecific interactions. Here we use the pond snail, Lymnaea stagnalis, to assess whether variability between natural populations (i.e., strains) in memory forming capabilities correlates with electrophysiological properties at the level of a single neuron, RPeD1. RPeD1 is a necessary site of LTM formation of aerial respiratory behaviour following operant conditioning. We used strains from two small, separate permanent ponds (TC1 and TC2). A comparison of the two populations showed that the TC1 strain had enhanced memory forming capabilities. Further, the behavioural phenotype of enhanced memory strain was explained, in part, by differences in the electrophysiology of RPeD1. Compared to RPeD1 from the naive TC2 strain, RPeD1 from the TC1 strain has both a decreased resistance and decreased excitability. Moreover, 24h after a single 0.5h training session, those membrane properties, as well as the firing and bursting rate, decrease further in the TC1 strain but not in the TC2 strain. The initial differences in RPeD1 properties in the TC1 strain coupled with their ability to further change these properties with a single training session suggests that RPeD1 neurons from the TC1 strain are "primed" to rapidly form memory.     

Inhibitory control and negative emotional processing in psychopathy and antisocial personality disorder

The field of personality disorders has had a long-standing interest in understanding interactions between emotion and inhibitory control, as well as neurophysiological indices of these processes. More work in particular is needed to clarify differential deficits in offenders with antisocial personality disorder (APD) who differ on psychopathic traits, as APD and psychopathy are considered separate, albeit related, syndromes. Evidence of distinct neurobiological processing in these disorders would have implications for etiology-based personality disorder taxonomies in future psychiatric classification systems. To inform this area of research, we recorded event-related brain potentials during an emotional-linguistic Go/No-Go task to examine modulation of negative emotional processing by inhibitory control in three groups: psychopathy (n = 14), APD (n = 16), and control (n = 15). In control offenders, inhibitory control demands (No-Go vs. Go) modulated frontal-P3 amplitude to negative emotional words, indicating appropriate prioritization of inhibition over emotional processing. In contrast, the psychopathic group showed blunted processing of negative emotional words regardless of inhibitory control demands, consistent with research on emotional deficits in psychopathy. Finally, the APD group demonstrated enhanced processing of negative emotion words in both Go and No-Go trials, suggesting a failure to modulate negative emotional processing when inhibitory control is required. Implications for emotion-cognition interactions and putative etiological processes in these personality disorders are discussed.     

Race/ethnicity and mental health in the first decade of the 21st century

Recent empirical studies on mental health generally report racial/ ethnic differences in depression rates but typically do not control for potential confounding by sample contextual variations in historical epoch, geographical location, and social demography. An empirical study of race/ethnicity differences in psychological distress is reported as an attempt to control these contexts by using a sample that is homogeneous in age, historical epoch, geography, and social demography (954 youth ages 18-19 living in a single, large urban community). No mean differences in psychological distress were observed among four racial/ethnic groups: Asians, African Americans, Latinos, and non-Hispanic Whites. A second analysis compared 17 different racial/ethnic groups defined in terms of family national origin. No differences in psychological distress were found among these groups. The findings are consistent with the view that race/ethnicity itself is not related to disparities in mental health.     

Feeling before knowing why: The role of the orbitofrontal cortex in intuitive judgments—an MEG study

In theory, intuitive decisions are made immediately, without conscious, reasoned thought. They are experienced as decisions based on hunches that cannot be explicitly described but, nevertheless, guide subsequent action. Investigating the underlying neural mechanisms, previous research has found the orbitofrontal cortex (OFC) to be crucial to intuitive processes, but its specific role has remained unclear. On the basis of a two-stage conceptualization of intuition suggested by Bowers, Regehr, Balthazard, and Parker Cognitive Psychology, 22, 72-110 (1990), we attempt to clarify the OFC’s role in intuitive processing. We propose that it functions as an early integrator of incomplete stimulus input guiding subsequent processing by means of a coarse representation of the gist of the information. On the subjective level, this representation would be perceived as a (gut) feeling biasing the decision. Our aim in the present study was to test this neural model and rule out alternative explanations of OFC activation in intuitive judgments. We used magnetoencephalography (MEG) to record participants' electromagnetic brain responses during a visual coherence judgment task. As in earlier studies, the OFC was found to be activated when participants perceived coherence. Using MEG, it could be shown that this increase in activation began earlier in the OFC than in temporal object recognition areas. Moreover, the present study demonstrated that OFC activation was independent of physical stimulus characteristics, task requirements, and participants’ explicit recognition of the stimuli presented. These results speak to the OFC’s fundamental role in the early steps of intuitive judgments and suggest the proposed neural model as a promising starting point for future investigations.     

Feeling happy enhances early spatial encoding of peripheral information automatically: electrophysiological time-course and neural sources

Previous research has shown that positive mood may broaden attention, although it remains unclear whether this effect has a perceptual or a postperceptual locus. In this study, we addressed this question using high-density event-related potential methods. We randomly assigned participants to a positive or a neutral mood condition. Then they performed a demanding oddball task at fixation (primary task ensuring fixation) and a localization task of peripheral stimuli shown at three positions in the upper visual field (secondary task) concurrently. While positive mood did not influence behavioral performance for the primary task, it did facilitate stimulus localization on the secondary task. At the electrophysiological level, we found that the amplitude of the C1 component (reflecting an early retinotopic encoding of the stimulus in V1) was enhanced in the positive, as compared with the neutral, mood group. Importantly, this effect appeared to be largely automatic, because it occurred regardless of the task relevance of the peripheral stimulus and prior to top-down gain control effects seen at the level of the subsequent P1 component. This early effect was also observed irrespective of a change of the target-related P300 component (primary task) by positive mood. These results suggest that positive mood can automatically boost the spatial encoding of peripheral stimuli early on following stimulus onset. This effect can eventually underlie the broadening of spatial attention, which has been associated with this specific mood state.     

Sensory memory of illusory depth in structure-from-motion

When multistable displays (stimuli consistent with two or more equally plausible perceptual interpretations) are presented intermittently, their perceptions are stabilized by sensory memory. Independent memory traces are generated not only for different types of multistable displays (Maier, Wilke, Logothetis, & Leopold, Current Biology 13:1076–1085, 2003), but also for different ambiguous features of binocular rivalry (Pearson & Clifford, Journal of Vision 4:196–202, 2004). In the present study, we examined whether a similar independence of sensory memories is observed in structure-from-motion (SFM), a multistable display with two ambiguous properties. In SFM, a 2-D planar motion creates a vivid impression of a rotating 3-D volume. Both the illusory rotation and illusory depth (i.e., how close parts of an object appear to the observer) of an SFM object are ambiguous. We dissociated the sensory memories of these two ambiguous properties by using an intermittent presentation in combination with a forced-ambiguous-switch paradigm (Pastukhov, Vonau, & Braun, PLoS ONE 7:e37734, 2012). We demonstrated that the illusory depth of SFM generates a sensory memory trace that is independent from that of illusory rotation. Despite this independence, the specificities levels of the sensory memories were identical for illusory depth and illusory rotation. The history effect was weakened by a change in the volumetric property of a shape (whether it was a hollow band or a filled drum volume), but not by changes in color or size. We discuss how these new results constrain models of sensory memory and SFM processing.     

Intersectional experiences of discrimination in a low‐resource urban community: An exploratory latent class analysis

There have been increasing calls for the application of an intersectionality framework to understand and address discrimination and health inequities among diverse communities. Yet there have been theoretical debates regarding to whom intersectionality applies and how intersectional experiences of discrimination are associated with health outcomes. The current study aimed to contribute to these theoretical debates and inform practical applications to reduce health inequities. Data were drawn from a community health survey in New Haven, CT (N = 1,293 adults) and analysed using latent class analysis. Results yielded 4 classes. Members of the 4 classes were similar sociodemographically. Three classes of participants reported experiencing discrimination, and members of these classes had greater stress, higher rates of smoking and sleep disruption, and worse overall health than members of the class reporting no discrimination. Members of 2 classes made multiple, or intersectional, attributions for discrimination, and members of these classes reported the most frequent discrimination. Findings suggest that community members who are sociodemographically similar may have diverse discrimination experiences. Multilevel interventions that address multiple forms of discrimination (e.g., racism and sexism) may hold promise for reducing discrimination and, ultimately, health inequities within low‐resource urban community settings.     

Ramón García,Featured Poet: Brother Bluebeard and Other Poems

In this commentary on the “Brother Bluebeard” sequence by featured poet Ramón García, I consider the profound and terrible revelations this mythic poem gives about our own dreaded times, as well as the wisdom it brings us, patterned on the archetype of initiation—descent into an underworld. In his gender-fluid retelling of the Bluebeard legend, the narrator of the poem is a man who sleeps with men, but who over the course of the poem identifies with the women whom Bluebeard has slaughtered. This is at once a highly political sequence of poems, in which we can recognize the Bluebeard in our current national story, a Jungian series of poems that illuminates the alchemical process of mortificatio and rebirth, and a story of trauma and spiritual recovery.