Variable heart rate and a flexible mind: Higher resting-state heart rate variability predicts better task-switching.

The neurovisceral integration model proposes that heart rate variability (HRV) is linked to prefrontal cortex activity via the vagus nerve, which connects the heart and the brain. HRV, an index of cardiac vagal tone, has been found to predict performance on several cognitive control tasks that rely on the prefrontal cortex. However, the link between HRV and the core cognitive control function "shifting" between tasks and mental sets is under-investigated.

Rumination impairs the control of stimulus-induced retrieval of irrelevant information, but not attention, control, or response selection in general.

The aim of the study was to throw more light on the relationship between rumination and cognitive-control processes. Seventy-eight adults were assessed with respect to rumination tendencies by means of the LEIDS-r before performing a Stroop task, an event-file task assessing the automatic retrieval of irrelevant information, an attentional set-shifting task, and the Attentional Network Task, which provided scores for alerting, orienting, and executive control functioning. The size of the Stroop effect and irrelevant retrieval in the event-five task were positively correlated with the tendency to ruminate, while all other scores did not correlate with any rumination scale.

Transcutaneous vagus nerve stimulation (tVNS) modulates flow experience.

Flow has been defined as a pleasant psychological state that people experience when completely absorbed in an activity. Previous correlative evidence showed that the vagal tone (as indexed by heart rate variability) is a reliable marker of flow. So far, it has not yet been demonstrated that the vagus nerve plays a causal role in flow.

More attentional focusing through binaural beats: evidence from the global-local task.

A recent study showed that binaural beats have an impact on the efficiency of allocating attention over time. We were interested to see whether this impact affects attentional focusing or, even further, the top-down control over irrelevant information. Healthy adults listened to gamma-frequency (40 Hz) binaural beats, which are assumed to increase attentional concentration, or a constant tone of 340 Hz (control condition) for 3 min before and during a global-local task.

Dopamine, norepinephrine, and the management of sensorimotor bindings: individual differences in updating of stimulus-response episodes are predicted by DAT1, but not DBH5'-ins/del.

Evidence suggests that the flexibility of managing (creating and updating) stimulus-response bindings is driven by the dopaminergic system. Given that striatal dopamine (DA) plays a crucial role in the updating of working memory, the present study tested whether individual differences in the efficiency of updating stimulus-response episodes (event files) are predicted by differences in genetic predisposition related to the efficiency of the striatal dopaminergic pathway. In view of contrasting claims that stimulus-response binding is related to norepinephrine, we also considered genetic predispositions regarding noradrenergic pathways.

The genetic impact (C957T-DRD2) on inhibitory control is magnified by aging.

Healthy aging beyond the age of 65 is characterized by a general decrease in cognitive control over actions: old adults have more difficulty than young adults in stopping overt responses. Responsible for this cognitive decrement is the continuous decline of striatal and extrastriatal dopamine (DA). The resource-modulation hypothesis assumes that genetic variability is more likely to result in performance differences when brain resources move away from close-to-optimal levels, as in aging.

Khat use is associated with increased response conflict in humans.

Objective: Khat consumption has become a worldwide phenomenon broadening from Eastern Africa and the south west of the Arabian Peninsula to ethnic communities in the rest of the world. Only few studies have systematically looked into cognitive impairments in khat users. We studied whether khat use is associated with changes in the emergence and resolution of response conflict, a central cognitive control function.

Loving-kindness brings loving-kindness: the impact of Buddhism on cognitive self-other integration.

Common wisdom has it that Buddhism enhances compassion and self-other integration. We put this assumption to empirical test by comparing practicing Taiwanese Buddhists with well-matched atheists. Buddhists showed more evidence of self-other integration in the social Simon task, which assesses the degree to which people co-represent the actions of a coactor.

Action video gaming and cognitive control: playing first person shooter games is associated with improvement in working memory but not action inhibition.

The interest in the influence of videogame experience in our daily life is constantly growing. "First Person Shooter" (FPS) games require players to develop a flexible mindset to rapidly react and monitor fast moving visual and auditory stimuli, and to inhibit erroneous actions. This study investigated whether and to which degree experience with such videogames generalizes to other cognitive control tasks.

Dopaminergic modulation of the updating of stimulus-response episodes in Parkinson's disease.

Increasing evidence suggests that the control of retrieval of episodic feature bindings is modulated by the striatal dopaminergic pathway. The present study investigated whether this may reflect a contribution from the ventral or the dorsal part of the striatum. Along the lines of the overdose hypothesis in Parkinson's disease (PD), functions known to rely on the dorsal striatum are enhanced with dopaminergic medication, while operations relying on the ventral circuitry are impaired.

Estrogen modulates inhibition of return in healthy human females.

Estrogen has a key role in explaining gender differences in dopaminergic functioning. To date, previous studies on estrogen have focused on inhibitory output control, such as the intentional suppression of overt pre-potent actions, but whether input control is also modulated is an open question. For the first time, this study compared the ability to perform a cued target-detection task that measured inhibition of return (IOR), a reflexive inhibitory mechanism that delays attention from returning to a previously attended location, in young women (n=21) across the three phases of their menstrual cycle (salivary estradiol and progesterone concentrations were assessed) and in young men (n=21).

Khat use is associated with impaired working memory and cognitive flexibility.

Rationale: Khat consumption has increased during the last decades in Eastern Africa and has become a global phenomenon spreading to ethnic communities in the rest of the world, such as The Netherlands, United Kingdom, Canada, and the United States. Very little is known, however, about the relation between khat use and cognitive control functions in khat users.

Objective: We studied whether khat use is associated with changes in working memory (WM) and cognitive flexibility, two central cognitive control functions.

BDNF Val66Met polymorphism is associated with higher anticipatory cortisol stress response, anxiety, and alcohol consumption in healthy adults.

Background: The brain-derived neurotrophic factor (BDNF) is a key protein in maintaining neuronal integrity. The BDNF gene is thought to play an important role in the pathophysiology of mood and anxiety disorders. The aim of this study was to investigate, for the first time in a single study, the association between BDNF Val(66)Met polymorphism, anxiety, alcohol consumption, and cortisol stress response.

Dopamine and the management of attentional resources: genetic markers of striatal D2 dopamine predict individual differences in the attentional blink.

The attentional blink (AB)--a deficit in reporting the second of two target stimuli presented in close succession in a rapid sequence of distracters--has been related to processing limitations in working memory. Given that dopamine (DA) plays a crucial role working memory, the present study tested whether individual differences in the size of the AB can be predicted by differences in genetic predisposition related to the efficiency of dopaminergic pathways. Polymorphisms related to mesocortical and nigrostriatal dopaminergic pathways were considered, as well as polymorphisms related to norepinephrine (NE), a transmitter system that has also been suspected to play a role in the AB.

Genetic markers of striatal dopamine predict individual differences in dysfunctional, but not functional impulsivity.

Various psychiatric disorders are characterized by elevated levels of impulsivity. Although extensive evidence supports a specific role of striatal, but not frontal dopamine (DA) in human impulsivity, recent studies on genetic variability have raised some doubts on such a role. Importantly, impulsivity consists of two dissociable components that previous studies have failed to separate: functional and dysfunctional impulsivity.

God: Do I have your attention?

Religion is commonly defined as a set of rules, developed as part of a culture. Here we provide evidence that practice in following these rules systematically changes the way people attend to visual stimuli, as indicated by the individual sizes of the global precedence effect (better performance to global than to local features). We show that this effect is significantly reduced in Calvinism, a religion emphasizing individual responsibility, and increased in Catholicism and Judaism, religions emphasizing social solidarity.

Estrogen modulates inhibitory control in healthy human females: evidence from the stop-signal paradigm.

Animal studies point to a role of estrogen in explaining gender differences in striatal dopaminergic functioning, but evidence from human studies is still lacking. Given that dopamine is crucial for controlling and organizing goal-directed behavior, estrogen may have a specific impact on cognitive control functions, such as the inhibition of prepotent responses. We compared the efficiency of inhibitory control (as measured by the stop-signal task) in young women across the three phases of their menstrual cycle (salivary estradiol and progesterone concentrations were assessed) and in young men.

Recreational cocaine polydrug use impairs cognitive flexibility but not working memory.

Rationale: Chronic use of cocaine is associated with dysfunctions in frontal brain regions and dopamine D2 receptors, with poorer mental flexibility and a reduced ability to inhibit manual and attentional responses. Little is known, however, about cognitive impairments in the upcoming type of recreational cocaine polydrug user (1-4 g monthly consumption).

Objective: We studied whether recreational cocaine polydrug users, who do not meet the criteria for abuse or dependence, showed impairments in working memory (WM) and cognitive flexibility.

Reduced attentional scope in cocaine polydrug users.

Cocaine is Europe's second preferred recreational drug after cannabis but very little is known about possible cognitive impairments in the upcoming type of recreational cocaine user (monthly consumption). We asked whether recreational use of cocaine impacts early attentional selection processes. Cocaine-free polydrug controls (n = 18) and cocaine polydrug users (n = 18) were matched on sex, age, alcohol consumption, and IQ (using the Raven's progressive matrices), and were tested by using the Global-Local task to measure the scope of attention.

Dopamine and inhibitory action control: evidence from spontaneous eye blink rates.

The inhibitory control of actions has been claimed to rely on dopaminergic pathways. Given that this hypothesis is mainly based on patient and drug studies, some authors have questioned its validity and suggested that beneficial effects of dopaminergic stimulants on response inhibition may be limited to cases of suboptimal inhibitory functioning. We present evidence that, in carefully selected healthy adults, spontaneous eyeblink rate, a marker of central dopaminergic functioning, reliably predicts the efficiency in inhibiting unwanted action tendencies in a stop-signal task.

Losing the big picture: how religion may control visual attention.

Despite the abundance of evidence that human perception is penetrated by beliefs and expectations, scientific research so far has entirely neglected the possible impact of religious background on attention. Here we show that Dutch Calvinists and atheists, brought up in the same country and culture and controlled for race, intelligence, sex, and age, differ with respect to the way they attend to and process the global and local features of complex visual stimuli: Calvinists attend less to global aspects of perceived events, which fits with the idea that people's attentional processing style reflects possible biases rewarded by their religious belief system.

Reduced spontaneous eye blink rates in recreational cocaine users: evidence for dopaminergic hypoactivity.

Chronic use of cocaine is associated with a reduced density of dopaminergic D2 receptors in the striatum, with negative consequences for cognitive control processes. Increasing evidence suggests that cognitive control is also affected in recreational cocaine consumers. This study aimed at linking these observations to dopaminergic malfunction by studying the spontaneous eyeblink rate (EBR), a marker of striatal dopaminergic functioning, in adult recreational users and a cocaine-free sample that was matched on age, race, gender, and personality traits.

Blinks of the eye predict blinks of the mind.

The Attentional Blink (AB)--a deficit in reporting the second of two target stimuli presented in close succession in a rapid sequence of distracters--has been related to individual processing limitations of working memory. Given the known role of dopamine (DA) in working memory processes, the present experiment tested the hypothesis that DA, and in particular the DA/D1 subsystem, plays a role in the AB. We present evidence that the spontaneous eyeblink rate (EBR), a functional marker of central dopaminergic function, reliably predicts the size of AB.