Working memory load reduces the late positive potential and this effect is attenuated with increasing anxiety

Emotion regulation decreases the processing of arousing stimuli, as indexed by the late positive potential (LPP), an electrocortical component that varies in amplitude with emotional arousal. Emotion regulation increases activity in the prefrontal areas associated with cognitive control, including the dosolateral prefrontal cortex (DLPFC). The present study manipulated working memory load, known to activate the DLPFC, and recorded the LPP elicited by aversive and neutral IAPS pictures presented during the retention interval. The LPP was larger on low-load compared to high-load trials, and on trials with aversive compared to neutral pictures. These LPP data suggest that emotional content and working memory load have opposing effects on attention to distracting stimuli. State anxiety was associated with reduced modulation of the LPP by working memory load. Results are discussed in terms of competition for attention between emotion and cognition and suggest a relationship between DLPFC activation and the allocation of attentional resources to distracting visual stimuli–a relationship that may be disrupted with increasing anxiety.     

Emotion regulation and amygdala-precuneus connectivity: Focusing on attentional deployment

Attentional deployment is an emotion regulation strategy that involves shifting attentional focus. Deploying attention to non-arousing, compared to arousing, regions of unpleasant images has been associated with reduced negative affect, reduced amygdala activation, and increased activity in fronto-parietal control networks. The current study examined neural correlates and functional connectivity associated with using attentional deployment to increase negative affect (deploying attention towards arousing unpleasant information) or to decrease negative affect (deploying attention away from arousing unpleasant information), compared to naturally viewing unpleasant images, in 42 individuals while concurrently monitoring eye movements. Directing attention to both arousing and non-arousing regions resulted in enhanced fronto-parietal activation compared to natural viewing, but only directing attention to non-arousing regions was associated with changes in amygdala activation. There were no significant differences in connectivity between naturally viewing unpleasant images and focusing on arousing regions. However, naturally viewing unpleasant images, relative to focusing on non-arousing regions, was associated with increased connectivity between the amygdala and visual cortex, while focusing on non-arousing regions of unpleasant images, compared to natural viewing, was associated with increased connectivity between the amygdala and the precuneus. Amygdala-precuneus connectivity correlated positively with eye-tracking measures of attentional deployment success and with trait reappraisal. Deploying attention away from arousing unpleasant information, then, may depend upon functional relationships between the amygdala and parietal regions implicated in attentional control. Furthermore, these relationships might relate to the ability to successfully implement attentional deployment, and the predisposition to utilize adaptive emotion regulation strategies.     

Heidegger and the Supposition of a Single,Objective World

Christina Lafont has argued that the early Heidegger's reflections on truth and understanding are incompatible with ‘the supposition of a single objective world’. This paper presents her argument, reviews some responses that the existing Heidegger literature suggests (focusing, in particular, on work by John Haugeland), and offers what I argue is a superior response. Building on a deeper exploration of just what the above ‘supposition’ demands (an exploration informed by the work of Bernard Williams and Adrian Moore), I argue that a crucial assumption that Lafont and Haugeland both accept must be rejected, namely, that different ‘understandings of Being’ can be viewed as offering ‘rival perspectives’ on a common subject‐matter. I develop this case by drawing on an alternative account of what a Heideggerian ‘understanding of Being’ might be like.     

Semantic involvement in reading aloud: evidence from a nonword training study

The current research uses a novel methodology to examine the role of semantics in reading aloud. Participants were trained to read aloud 2 sets of novel words (i.e., nonwords such as bink): some with meanings (semantic) and some without (nonsemantic). A comparison of reading aloud performance between these 2 sets of novel words was used to provide an indicator of the importance of semantic information in reading aloud. In Experiment 1, in contrast to expectations, reading aloud performance was not better for novel words in the semantic condition. In Experiment 2, the training of novel words was modified to reflect more realistic steps of lexical acquisition: Reading aloud performance became faster and more accurate for novel words in the semantic condition, but only for novel words with inconsistent pronunciations. This semantic advantage for inconsistent novel words was again observed when a subset of participants from Experiment 2 was retested 6-12 months later (in Experiment 3). These findings provide support for a limited but significant role for semantics in the reading aloud process.     

Performance of Ethical Military Research is Possible: On and Off the Battlefield

Many of the same fundamental principles and regulations that govern civilian biomedical research also apply to research conducted by the US Military. Despite these similarities, the conduct of research by the US Military has additional requirements designed to preserve service members' informed consent rights, ethical standards and information that may be deemed classified. Furthermore, there are also additional rules and regulations associated with potential research to be done in a combat setting. Before conducting battlefield research, many unique circumstances must be considered to include: (1) the current legal and regulatory requirements for advanced informed consent (2) the tactical situations, and the ability to adequately document in the "austere" environment (3) the need to provide improved drugs and devices for combat casualty care and (4) the special nature of the superior-subordinate relationship. This paper discusses historical background, regulatory oversight, ethical implications and release of information as it pertains to research conducted by the US Military.     

Abnormal Neural Sensitivity to Monetary Gains Versus Losses Among Adolescents at Risk for Depression

Major depressive disorder aggregates within families, although the mechanisms of transfer across generations are not well understood. In light of converging biological and behavioral evidence that depressive symptoms are associated with impaired reward processing, we examined whether adolescent girls with a parental history of depression would also exhibit abnormal reward sensitivity. We performed a negative mood induction and then recorded the feedback negativity, a neural index of reward processing, while individuals completed a gambling task. High-risk adolescents reported greater sadness following the mood induction compared to low-risk adolescents. Among the high-risk group, sadness was strongly associated with a blunted feedback negativity, even after controlling for baseline mood and trait neuroticism. This suggests that high-risk adolescents are more reactive to negative stimuli, which significantly alter neural sensitivity to monetary gains and losses. The feedback negativity might be used to identify information processing abnormalities in high-risk populations prior to the onset of a major depressive episode.     

Glucocorticoids are required for extinction of predator stress-induced hyperarousal

Background

The role of glucocorticoids in extinction of traumatic memories has not been fully characterized despite its potential as a therapeutic target for acquired posttraumatic stress disorder (PTSD). The predator stress paradigm allows us to determine whether glucocorticoids mediate the extinction of both context-dependent and context-independent fear memories.

Methods

Male C57BL/6J mice were exposed to a predator (cat) then repeatedly exposed to the predator stress context in the absence of the cat. Context-dependent (associative) fear memory was assessed as suppression of activity during re-exposure to the predator stress context without the cat (extinction trials). Context-independent fear (non-associative) was assessed seven days after extinction trials using measures of hyperarousal and anxiety-like behaviours in environments unlike the predator stress context. To assess the role of glucocorticoids, mice were injected with metyrapone (50 mg/kg) 90 min prior to extinction trials in predator stressed mice and context-dependent and context-independent fear memories were assessed. Finally, metyrapone-treated predator stressed mice were injected with corticosterone (5 or 10 mg/kg) immediately following extinction trials and context-dependent and context-independent fear memories were assessed.

Results

Repeated re-exposure to the predator stress context without the cat present extinguished context-dependent fear memory, and also reduced hyperarousal, a generalized, chronic PTSD-like symptom. We show that extinction of context-independent predator stress-induced hyperarousal is dependent on endogenous glucocorticoids during the extinction trials. Furthermore, the inhibition of extinction by metyrapone on startle amplitude was reduced by exogenous administration of corticosterone following extinction trials. Overall, these data implicate glucocorticoids in the extinction of hyperarousal, a core symptom of PTSD.     

Developmental change and the multidimensional cognitive system

The cognitive system is a multidimensional, hierarchically-structured arrangement of cognitive dimensions functionally organized into three subsystems: perceiving, conceptualizing, and symbolizing. Ontogenetic change in these subsystems is described using theoretical concepts from both multivariate developmental psychology and systems theory. Both quantitative and qualitative changes in cognitive dimensions are discussed, including a synthesis of relevant empirical research. The Gompertz equation is used to describe the general form of quantitative change throughout the life-span. The pattern oo quantitative development involves growth, stability, and decline. The pattern of qualitative development, or shifts in structural organization, also invloves three periods: divergence, parallelism, and paraller-convergence. Thus, the overall quantitative-qualitative synthesis reveals a three-phase sequence of cognitive development: divergent growth (childhood- adolescence), parallel stability (adulthood), and parallel-convergent decline (old age).     

Between-object binding and visual attention

Many previous studies have found that we can attend pairs of visual features (e.g., colour, orientation) more efficiently when they belong to the same “object” compared to when they belong to separate, neighbouring objects (e.g., Behrmann, Zemel, & Mozer, 1998; Egly, Rafal, & Driver, 1994). This advantage for attending features from the same object may reflect stronger binding between these features than arises for pairs of features belonging to separate objects. However, recent findings described by Davis, Welch, Holmes, and Shepherd (in press) suggest that under specific conditions this same-object advantage can be reversed, such that attention now spreads more readily between features belonging to separate neighbouring objects than between features of the same object. In such cases it would appear that features belonging to separate visual objects are more strongly bound than features of the same object. Here I review these findings and present the results of a new study. Together these data suggest that magnocellular processes in the human visual system bind together features from separate objects, whereas parvocellular processes bind together features from the same object.