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AbstractBackgroundNeurobehavioral research on the role of impulsivity in gambling disorder (GD) has produced heterogeneous findings. Impulsivity is multifaceted with different experimental tasks measuring different subprocesses, such as response inhibition and distractor interference. Little is known about the neurochemistry of inhibition and interference in GD.MethodsWe investigated inhibition with the stop signal task (SST) and interference with the Eriksen Flanker task, and related performance to metabolite levels in individuals with and without GD. We employed magnetic resonance spectroscopy (MRS) to record glutamate–glutamine (Glx/Cr) and inhibitory, γ-aminobutyric acid (GABA+/Cr) levels in the dorsal ACC (dACC), right dorsolateral prefrontal cortex (dlPFC), and an occipital control voxel.ResultsWe found slower processing of complex stimuli in the Flanker task in GD (P< .001, η2p= 0.78), and no group differences in SST performance. Levels of dACC Glx/Cr and frequency of incongruent errors were correlated positively in GD only (r= 0.92, P= .001). Larger positive correlations were found for those with GD between dACC GABA+/Cr and SST Go error response times (z= 2.83, P= .004), as well as between dACC Glx/Cr and frequency of Go errors (z= 2.23, P= .03), indicating general Glx-related error processing deficits. Both groups expressed equivalent positive correlations between posterror slowing and Glx/Cr in the right dlPFC (GD: r= 0.74, P= .02; non-GD: r= .71, P= .01).ConclusionInhibition and interference impairments are reflected in dACC baseline metabolite levels and error processing deficits in GD.

There has been increasing interest in the use of coronary flow reserve measurements to define pathophysiology in various patient groups and to make individual patient management decisions. The concept of coronary flow reserve has provided a method for describing the capacity to conduct maximal hyperemic blood flow. Coronary flow reserve is the ratio of maximal to resting coronary blood flow. The study of coronary circulation in humans has been made possible through the development of several methods.[1-6] Currently, the most extensively used and validated method is the transluminal, subselective measurement of coronary blood flow velocity and vasodilator reserve.[1] The use of intracoronary Doppler catheters permits rapid and accurate measurements of coronary vasodilator responses to various pharmacologic and physiologic stimuli.[7-9] However, the major limitation of this technique is instrumentation of the coronary artery with an angioplasty guide wire and the Doppler catheter, which requires considerable operator experience and also has the possibility of potential serious vascular complications such as dissection, vasospasm and thrombosis. Systemic heparinization is also required. Recently a new Judkins-style Doppler-tipped angiographic catheter has been developed to facilitate a more rapid and safe measurement of coronary flow reserve.6 We assessed whether the coronary flow reserve measurements obtained with these catheters are comparable to those achieved with the intracoronary Doppler catheter technique.

Paul Mullins Retail designer Lance Armstrong, cycling legend, at 25 ranked number one in the world. He is diagnosed with a very aggressive form of cancer and given a less [...]

The suprachiasmatic nucleus of the hypothalamus is the chief circadian pacemaker in the brain, and is entrained to day-night cycles by visual afferents from melanopsin containing retinal ganglion cells via the inferior accessory optic tract. Tracer studies have demonstrated efferents from the suprachiasmatic nucleus projecting to the paraventricular nucleus of the hypothalamus, which in turn project to first-order sympathetic neurons in the intermedio-lateral grey of the spinal cord. Sympathetic projections to the pineal gland trigger the secretion of the sleep inducing hormone melatonin. The current study reports the first demonstration of potential sympathopetal hypothalamic projections involved in circadian regulation in humans with in vivovirtual white matter dissections using probabilistic diffusion tensor imaging (DTI) tractography. Additionally, our data shows a correlation between individual differences in white matter microstructure (measured with fractional anisotropy) and increased daytime sleepiness [measured with the Epworth Sleepiness Scale (ESS, Johns, 1991)]. Sympathopetal connections with the hypothalamus were virtually dissected using designated masks on the optic chiasm, which served as an anatomical landmark for retinal fibres projecting to the suprachiasmatic nucleus, and a waypoint mask on the lateral medulla, where hypothalamic projections to the sympathetic nervous system traverse in humans. Sympathopetal projections were demonstrated in each hemisphere in twenty-six subjects. The tract passed through the suprachiasmatic nucleus of the hypothalamus and its trajectory corresponds to the dorsal longitudinal fasciculus traversing the periaqueductal region and the lateral medulla. White matter microstructure (FA) in the left hemisphere correlated with high scores on the ESS, suggesting an association between circadian pathway white matter microstructure, and increased daytime sleepiness.

This commentary examines Michael Roller’s metaphor of the machine to describe the social conditioning associated with 20th-century mass consumption. Roller’s machinic mass consumerism evokes familiar anxieties in its illumination of the ways consumer materiality shapes human experience. The hazard is that machinic mass consumerism risks understating the everyday creativity, retreat, silence, and imagination that negotiate and upset the machinery of mass consumer culture. En este comentario se examina la metáfora de la máquina de Michael Roller que se utiliza para describir el condicionamiento social asociado con el consumo de masas del siglo XX. El consumismo de masas "maquínico" evoca ansiedades familiares al iluminar las maneras en que la materialidad del consumidor moldea la experiencia humana. El riesgo es que el consumismo de masas maquínico corra el peligro de subestimar la creatividad, retiro, silencio e imaginación de la vida cotidiana que traspasan y alteran la maquinaria de la cultura de consumo de masas. Le présent commentaire examine la métaphore de la machine de Michael Roller utilisée pour décrire le conditionnement social associé à la consommation en masse du 20e siècle. Le consumérisme « machinique » en masse de Roller évoque des anxiétés familières en faisant la lumière sur la façon dont la matérialité du consommateur donne forme à l’expérience humaine. Le danger est que le consumérisme machinique en masse minimise la créativité, le retrait, le silence et l’imagination de tous les jours qui négocient et remettent en question la culture de consommation en masse de la machinerie.