Emotional modulation of pain-related evoked potentials

To investigate whether cortical processing of trigeminal nociception is modulated by emotion, the N2 and P2 components of the pain-related evoked potential (PREP) were recorded in response to noxious stimulation of the supraorbital nerve while participants viewed neutral, pleasant and unpleasant pictures. The nerve was stimulated at 125% of pain threshold via a nociceptive-specific concentric electrode to selectively activate A-delta pain fibres. The N2 and P2 pain-related evoked potentials were similarly influenced by emotional priming: the amplitude of both potentials decreased monotonically from viewing neutral to pleasant to unpleasant pictures. These findings show that cortical processing of trigeminal nociception is modulated by emotion. We explain our findings in terms of the effects of picture viewing on attention

Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis.

Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Medial frontal brain potentials following feedback during probabilistic learning.

Over 10 years after its discovery, controversy still abounds over the functional significance of an event-related potential known as the Error-Related Negativity (ERN). A number of theories (and models constructed from them) have been proposed in an attempt to explain it, including an error detection theory (the mismatch hypothesis), a conflict-monitoring theory, a reinforcement learning theory and an affective processing theory. These theories have received mixed empirical support and none stands out as more compelling than the others. The reinforcement learning theory of the ERN (RL-ERN) provides the latest endeavor to derive an explicit model of the functional significance of the ERN. This is an innovative and sophisticated model of the ERN that generates a number of new predictions about the effects of experimental manipulations on the ERN. One key prediction of the RL-ERN model is that the amplitude of the ERN will be larger when an event is worse than expected. A series of experiments was performed to test this prediction and assess the ERN over the course of learning. The tasks required participants to learn probabilistic associations between either stimuli and outcomes, or stimuli and responses. Participants' accuracy and their confidence in their performance were measured in order to assess their expectations explicitly. While some results were consistent with the RL-ERN model, others provided little support for it; in particular, the ERN was not found to be larger following unexpected error feedback (i.e., an event that is worse than expected), relative to expected error feedback (i.e., an event that is expected). In fact, the results suggest that the ERN is largest early in learning and when the association has not been learnt, suggesting it is largest before expectations can be developed; this has implications for other theories of the ERN as well as the RL-ERN. On the basis of these results and existing literature, an affective, or motivational, function is ascribed to the ERN as part of a more integrated system, involved in the processing of motivationally significant stimuli, whose functions include allocation of attention, arousal, preparation for action and learning.Ph.D.Cognitive psychologyPsychologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/124977/2/3163969.pd

Reconceptualizing mind wandering from a switching perspective

Mind wandering is a universal phenomenon in which our attention shifts away from the task at hand toward task-unrelated thoughts. Despite it inherently involving a shift in mental set, little is known about the role of cognitive flexibility in mind wandering. In this article we consider the potential of cognitive flexibility as a mechanism for mediating and/or regulating the occurrence of mind wandering. Our review begins with a brief introduction to the prominent theories of mind wandering—the executive failure hypothesis, the decoupling hypothesis, the process-occurrence framework, and the resource-control account of sustained attention. Then, after discussing their respective merits and weaknesses, we put forward a new perspective of mind wandering focused on cognitive flexibility, which provides an account more in line with the data to date, including why older populations experience a reduction in mind wandering. After summarizing initial evidence prompting this new perspective, drawn from several mind-wandering and task-switching studies, we recommend avenues for future research aimed at further understanding the importance of cognitive flexibility in mind wandering

Spontaneous Mind-Wandering Tendencies Linked to Cognitive Flexibility in Young Adults

Despite that previous studies have investigated mind wandering using task-switching paradigms, the association between the tendency to mind wander and cognitive flexibility remains largely unexplored. The present study investigated the relationship between self-reported spontaneous mind-wandering tendencies and task-switching performance in young adults. Seventy-nine university students performed a forced task-switching and a voluntary task-switching paradigm and then completed a battery of questionnaires. The results showed that compared to participants with lower spontaneous mind-wandering tendencies, participants with higher spontaneous mind-wandering tendencies demonstrated better performance (evidenced by smaller switch cost reaction times) in the forced task-switching paradigm despite indicating more mind wandering during task performance. Performance on the voluntary task-switching paradigm, on the other hand, did not differ between the two groups. The findings in the forced task-switching paradigm indicate a link between mind wandering and cognitive flexibility, thus providing initial evidence in favor of a role for switching in mind wandering

Electrophysiological characterization of sleep/wake, activity and the response to caffeine in adult cynomolgus macaques

Most preclinical sleep studies are conducted in nocturnal rodents that have fragmented sleep in comparison to humans who are primarily diurnal, typically with a consolidated sleep period. Consequently, we sought to define basal sleep characteristics, sleep/wake architecture and electroencephalographic (EEG) activity in a diurnal non-human primate (NHP) to evaluate the utility of this species for pharmacological manipulation of the sleep/wake cycle. Adult, 9–11 y.o. male cynomolgus macaques (n = 6) were implanted with telemetry transmitters to record EEG and electromyogram (EMG) activity and Acticals to assess locomotor activity under baseline conditions and following injections either with vehicle or the caffeine (CAF; 10 mg/kg, i.m.) prior to the 12 h dark phase. EEG/EMG recordings (12–36 h in duration) were analyzed for sleep/wake states and EEG spectral composition. Macaques exhibited a sleep state distribution and architecture similar to previous NHP and human sleep studies. Acute administration of CAF prior to light offset enhanced wakefulness nearly 4-fold during the dark phase with consequent reductions in both NREM and REM sleep, decreased slow wave activity during wakefulness, and increased higher EEG frequency activity during NREM sleep. Despite the large increase in wakefulness and profound reduction in sleep during the dark phase, no sleep rebound was observed during the 24 h light and dark phases following caffeine administration. Cynomolgus macaques show sleep characteristics, EEG spectral structure, and respond to CAF in a similar manner to humans. Consequently, monitoring EEG/EMG by telemetry in this species may be useful both for basic sleep/wake studies and for pre-clinical assessments of drug-induced effects on sleep/wake. Keywords: Sleep, NREM, REM, EEG, Cynomolgus macaque, Caffein