Suggested visual blockade during hypnosis: Top-down modulation of stimulus processing in a visual oddball task.

Several theories of hypnosis assume that responses to hypnotic suggestions are implemented through top-down modulations via a frontoparietal network that is involved in monitoring and cognitive control. The current study addressed this issue re-analyzing previously published event-related-potentials (ERP) (N1, P2, and P3b amplitudes) and combined it with source reconstruction and connectivity analysis methods. ERP data were obtained from participants engaged in a visual oddball paradigm composed of target, standard, and distractor stimuli during a hypnosis (HYP) and a control (CON) condition.

Suggested deafness during hypnosis and simulation of hypnosis compared to a distraction and control condition: A study on subjective experience and cortical brain responses.

Hypnosis is a powerful tool to affect the processing and perception of stimuli. Here, we investigated the effects of hypnosis on the processing of auditory stimuli, the time course of event-related-potentials (ERP; N1 and P3b amplitudes) and the activity of cortical sources of the P3b component. Forty-eight participants completed an auditory oddball paradigm composed of standard, distractor, and target stimuli during a hypnosis (HYP), a simulation of hypnosis (SIM), a distraction (DIS), and a control (CON) condition.

What you give is what you get: Payment of one randomly selected trial induces risk-aversion and decreases brain responses to monetary feedback.

In economic studies, it is standard practice to pay out the reward of only one randomly selected trial (pay-one) instead of the total reward accumulated across trials (pay-all), assuming that both methods are equivalent. We tested this assumption by recording electrophysiological activity to reward feedback from participants engaged in a decision-making task under both a pay-one and a pay-all condition. We show that participants are approximately 12% more risk averse in the pay-one condition than in the pay-all condition.

Pain-related and negative semantic priming enhances perceived pain intensity.

Background: Negative affective and pain-related cues, such as pictures or words, have been shown to act as primes and enhance the perceived intensity of subsequent painful events. For pain-related semantic primes, it remains unclear whether this effect depends on negative valence itself or, specifically, on the pain-relatedness of the words.

Objectives: To investigate the effect of pain-related, negative affective (pain-unrelated) and neutral semantic primes on the perception of subsequent noxious target stimuli.

How bad was it? Differences in the time course of sensitivity to the magnitude of loss in problem gamblers and controls.

Previous research has shown that pathological gamblers show various cognitive distortions, especially in interpreting near losses. Using a modified blackjack task, we investigated the electrophysiological responses to near and full losses in problem gamblers and controls. We assessed the event-related brain potentials (ERPs) of 20 problem gamblers and 21 controls at two time points following negative game outcomes.

Neural correlates of fair behavior in interpersonal bargaining.

Research findings show that proposers make surprisingly fair offers in the ultimatum and dictator games, an observation that contradicts predictions of classical game theory. The present functional magnetic resonance imaging (fMRI) study examines brain activities of proposers that contribute to fair and unfair behaviors. We hypothesized that egoistic and altruistic motives of proposers affect fairness differentially in the two games.

The influence of the magnitude, probability, and valence of potential wins and losses on the amplitude of the feedback negativity.

We assessed the influence of the variables outcome potential, feedback valence, magnitude, and probability on the amplitude of the feedback negativity (FN). Outcome potential was defined as the a priori valence of an upcoming feedback, that is, is there a potential win or potential loss? All these variables have been studied previously, although never together, but the findings have been contradictory. We analyzed the event-related potential (ERP) after feedback presentation in a reinforcement-learning task to examine the effects of all the variables on feedback negativity.

Dissociation of Pe and ERN/Ne in the conscious recognition of an error.

We evaluated the relationship between conscious awareness and the ERN/Ne and Pe in a digit entering task. On each trial, participants rated the accuracy of their responses on a three-point scale (incorrect, unsure, correct). The ERN/Ne was present on incorrect trials judged as incorrect.

Dissociation of acquisition and expression of fear conditioned responses under working memory load.

Previously, it has been suggested that high working memory load (WML) prevents associative learning and, thus, conditioned responses (CRs) during differential-delay fear conditioning. However, previous studies did not distinguish between the effects of WML on the acquisition versus the expression of the CRs. In the present study, we reinvestigated this issue by manipulating WML during either acquisition or postconditioning and showed that the absence of a differential CR under high WML does not indicate the absence of the acquisition of this CR.

Why humans deviate from rational choice.

Rational choice theory predicts that humans always optimize the expected utility of options when making decisions. However, in decision-making games, humans often punish their opponents even when doing so reduces their own reward. We used the Ultimatum and Dictator games to examine the affective correlates of decision-making.

Hypersensitivity to reward in problem gamblers.

Background: Recent research has begun to examine the neurophysiologic basis of pathological gambling. However, direct evidence of a behavioral deficit and an accompanying neurofunctional deviation in a realistic gambling context such as Black Jack has not yet been reported.

Methods: Electroencephalogram was recorded while 20 problem gamblers and 21 control participants played a computerized version of Black Jack.

Decision-making under risk: an fMRI study.

Recent research has focused on decision-making under risk and its neural bases. Two kinds of bad decisions under risk may be defined: too risky decisions and too cautious decisions. Here we show that suboptimal decisions of both kinds lead to increased activity in the anterior cingulate cortex in a Blackjack gambling task.

An electrophysiological analysis of coaching in Blackjack.

Recent research has demonstrated that a negative deflection in the event-related potential (ERP) that is usually elicited by errors, negative performance feedback, and monetary losses, and which has been associated with response monitoring and reinforcement learning, is also present when we observe others. In the present study we aimed to extend these findings to the domain of coaching behavior. In many contexts of human social life, advice is given by experts to novices, e.

Drive for thinness and attention toward specific body parts in a nonclinical sample.

Objective: To examine the differences between participants scoring high versus low on a drive for thinness construct concerning their visual attention toward specific body parts. We hypothesized that participants scoring high on the drive for thinness subscale would show increased attention to body regions, which are important in the assessment of body weight and thinness like the waist, hips, legs, and arms.

Method: We examined eye-gaze behavior of a nonclinical sample of 51 male and female college students with an eye-tracking system as they were looking at pictures of young, attractive males and females.

Brain activation upon selective stimulation of cutaneous C- and Adelta-fibers.

Thermal and nociceptive cutaneous stimuli activate the brain via two types of nerve fibers, slightly myelinated Adelta-fibers with moderate conduction velocity and unmyelinated C-fibers with slow conduction velocity. Differences in central processing upon selective stimulation of these two fiber types in healthy human subjects still remain poorly understood. By means of event-related functional magnetic resonance imaging the present study investigated brain activation in response to stimulation of Adelta- and C-fibers in healthy subjects.

How do brain areas communicate during the processing of noxious stimuli? An analysis of laser-evoked event-related potentials using the Granger causality index.

Several imaging techniques have identified different brain areas involved in the processing of noxious stimulation and thus in the constitution of pain. However, only little is known how these brain areas communicate with one another after activation by stimulus processing and which areas directionally affect or modulate the activity of succeeding areas. One measure for the analysis of such interactions is represented by the Granger Causality Index (GCI).

Attentional Blink to emotional and threatening pictures in spider phobics: electrophysiology and behavior.

When two targets have to be identified in a rapid serial visual presentation (RSVP) paradigm, perception of the second target (T2) becomes significantly impaired if it is displayed 200-500 ms after the first target (T1), a phenomenon labeled as "Attentional Blink" (AB). Here we investigate 14 spider phobics and 16 controls in an RSVP paradigm with neutral T1s. T2 pictures were neutral, emotional (positive or negative) or threatening (spiders for spider phobics).

Decision-making in Blackjack: an electrophysiological analysis.

Previous studies have identified a negative potential in the event-related potential (ERP), the error-related negativity (ERN), which is claimed to be triggered by a deviation from a reward expectation. Furthermore, this negativity is related to shifts in risk taking, strategic behavioral adjustments, and inhibition. We used a computer Blackjack gambling task to further examine the process associated with the ERN.

Event-related brain potentials and affective responses to threat in spider/snake-phobic and non-phobic subjects.

We investigated cortical responses and valence/arousal ratings of spider phobic, snake phobic, and healthy subjects while they were processing feared, fear-relevant, emotional neutral, and pleasant stimuli. Results revealed significantly larger amplitudes of late ERP components (P3 and late positive complex, LPC) but not of early components (N1, P2, N2) in phobics when subjects were processing feared stimuli. This fear-associated increase of amplitudes of late ERP components in phobic subjects was maximal at centro-parietal and occipital brain sites.

Eye movements and behavioral responses to threatening and nonthreatening stimuli during visual search in phobic and nonphobic subjects.

Spider-phobic and nonphobic subjects searched for a feared/fear-relevant (spider) or neutral target (mushroom) presented in visual matrices of neutral objects (flowers). In half of the displays, the mushroom target was paired with a spider distractor, or a spider target was paired with a mushroom distractor. Although all subjects responded faster to the neutral target than to the feared/fear-relevant target, phobics were slower to respond than nonphobics when a mushroom target was presented with a spider distractor.

Acupuncture decreases somatosensory evoked potential amplitudes to noxious stimuli in anesthetized volunteers.

Unlabelled: The effect of acupuncture on pain perception is controversial. Because late amplitudes of somatosensory evoked potentials (SEPs) to noxious stimuli are thought to correlate with the subjective experience of pain intensity, we designed this study to detect changes of these SEPs before and after acupuncture in a double-blinded fashion. Sixteen volunteers were anesthetized by propofol and exposed to painful electric stimuli to the right forefinger.

Brain activation to phobia-related pictures in spider phobic humans: an event-related functional magnetic resonance imaging study.

Using event-related functional magnetic resonance imaging we investigated blood oxygen level dependent brain activation in spider phobic and non-phobic subjects while exposed to phobia-related pictures (spiders) and non-phobia-related pictures (snakes and mushrooms). In contrast to previous studies, we show significantly increased amygdala activation in spider phobics, but not in controls, during presentation of phobia-relevant visual stimuli. Furthermore, phobia-specific increased activation was also found in the insula, the orbitofrontal cortex and the uncus.