Impulsivity as a mediating factor in the association between posttraumatic stress disorder symptoms and substance use.

Objective: Posttraumatic stress disorder (PTSD) has been associated with heightened impulsivity and risk-taking behaviors, including higher rates of substance use than individuals without PTSD. Although a number of studies suggest that impulsivity is associated with substance use in PTSD, the specific role of impulsivity in this common pattern of comorbidity remains unclear. The current study investigated associations between PTSD symptoms, substance use patterns, and impulsivity in a sample of adults.

Discounting of delayed monetary and cannabis rewards in a crowdsourced sample of adults.

Excessive delayed reward discounting (DD) is observed across many addictive disorders. However, research on DD among cannabis users is limited, with even less research on discounting of cannabis rewards. This study examined monetary and cannabis reward discounting among cannabis and noncannabis users.

Delay Discounting as a Transdiagnostic Process in Psychiatric Disorders: A Meta-analysis.

Importance: Delay discounting is a behavioral economic index of impulsive preferences for smaller-immediate or larger-delayed rewards that is argued to be a transdiagnostic process across health conditions. Studies suggest some psychiatric disorders are associated with differences in discounting compared with controls, but null findings have also been reported.

Objective: To conduct a meta-analysis of the published literature on delay discounting in people with psychiatric disorders.

Effects of neuromodulation on cognitive performance in individuals exhibiting addictive behaviors: A systematic review.

Background: There is growing interest in non-invasive brain stimulation techniques as treatments for addictive disorders. While multiple reviews have examined the effects of neuromodulation on craving and consumption, there has been no review of how neuromodulation affects cognitive functioning in addiction. This systematic review examined studies of the cognitive effects of transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS) in individuals exhibiting addictive behavior.

Systematic review of the effects of acute stress in binge eating disorder.

Binge eating disorder (BED) is characterized by recurrent episodes of eating an excessive amount of food over a discrete time period, while feeling a loss of control over one's eating. Although stress is one of the most commonly reported triggers of binge eating in individuals with BED, there has been little work examining the stress response specifically in individuals with the disorder. In this review, we examine what is known about how individuals with BED respond to acute stressors.

Effects of neuromodulation on cognitive performance in individuals exhibiting addictive behaviour: a systematic review protocol.

Background: Individuals with substance use and addictive disorders often display greater risk-taking behaviour, higher impulsivity, and altered reward processing compared to individuals without these disorders. While it is not known whether cognitive biases precede or result from addictive behaviour, they likely influence addiction-related decision-making, and may facilitate pathological behaviour. There is evidence that cognitive functions-including those shown to be altered in substance use and addictive disorders-can be influenced by neuromodulation techniques (specifically, transcranial direct current stimulation and transcranial magnetic stimulation).

Observing painful events in others leads to a temporally extended general response facilitation in the self.

Excitability in the motor cortex is modulated when we observe other people receiving a painful stimulus (Avenanti et al., Nat Neurosci 8(7):955-960, 2005). However, the task dependency of this modulation is not well understood, as different paradigms have yielded seemingly different results.

Effects of intentional movement preparation on response times to symbolic and imitative cues.

Speeded responses to an external cue are slower when the cue interrupts preparation to perform the same or a similar action in a self-paced manner. To explore the mechanism underlying this 'cost of intention', we examined whether the size of the cost is influenced by the nature of the external cue. Specifically, we assessed whether the cost of intention is different for movements made in response to an imitative cue (an on-screen hand movement) compared to those made in response to a symbolic cue.

Stimulation over primary motor cortex during action observation impairs effector recognition.

Recent work suggests that motor cortical processing during action observation plays a role in later recognition of the object involved in the action. Here, we investigated whether recognition of the effector making an action is also impaired when transcranial magnetic stimulation (TMS) - thought to interfere with normal cortical activity - is applied over the primary motor cortex (M1) during action observation. In two experiments, single-pulse TMS was delivered over the hand area of M1 while participants watched short clips of hand actions.

Self-selected conscious strategies do not modulate motor cortical output during action observation.

The human motor system is active not only when actions are performed but also when they are observed. Experimenters often manipulate aspects of the action or context to examine factors that influence this "mirror" response. However, little is known about the role of the observer's own top-down intentions and motivation.

Timing and specificity of early changes in motor excitability during movement observation.

Motor resonance is typically considered a modulation of motor activity during action observation, which mirrors the pattern of muscle activation occurring during execution of the observed action. There is preliminary evidence that motor activity accompanying action observation comprises two stages: an initial non-specific modulation, followed by a later change in excitability that is specific to the muscles involved in the action. We built on this previous work, with the aims of (1) clarifying the time-course of muscle specificity during action observation and (2) establishing whether modulation at each time point reflects significant changes (facilitation or suppression) from baseline.

Effects of action observation on corticospinal excitability: Muscle specificity, direction, and timing of the mirror response.

Many human behaviours and pathologies have been attributed to the putative mirror neuron system, a neural system that is active during both the observation and execution of actions. While there are now a very large number of papers on the mirror neuron system, variations in the methods and analyses employed by researchers mean that the basic characteristics of the mirror response are not clear. This review focuses on three important aspects of the mirror response, as measured by modulations in corticospinal excitability: (1) muscle specificity; (2) direction; and (3) timing of modulation.

To eat or not to eat? Kinematics and muscle activity of reach-to-grasp movements are influenced by the action goal, but observers do not detect these differences.

Recent evidence suggests that the mirror neuron system responds to the goals of actions, even when the end of the movement is hidden from view. To investigate whether this predictive ability might be based on the detection of early differences between actions with different outcomes, we used electromyography (EMG) and motion tracking to assess whether two actions with different goals (grasp to eat and grasp to place) differed from each other in their initial reaching phases. In a second experiment, we then tested whether observers could detect early differences and predict the outcome of these movements, based on seeing only part of the actions.

Food intake is influenced by sensory sensitivity.

Wide availability of highly palatable foods is often blamed for the rising incidence of obesity. As palatability is largely determined by the sensory properties of food, this study investigated how sensitivity to these properties affects how much we eat. Forty females were classified as either high or low in sensory sensitivity based on their scores on a self-report measure of sensory processing (the Adult Sensory Profile), and their intake of chocolate during the experiment was measured.