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Ergebnisse 4 Einträge
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Following the idea that response inhibition processes play a central role in concealing information, the present study investigated the influence of a Go/No-go task as an interfering mental activity, performed parallel to the Concealed Information Test (CIT), on the detectability of concealed information. 40 undergraduate students participated in a mock-crime experiment and simultaneously performed a CIT and a Go/No-go task. Electrodermal activity (EDA), respiration line length (RLL), heart rate (HR) and finger pulse waveform length (FPWL) were registered. Reaction times were recorded as behavioral measures in the Go/No-go task as well as in the CIT. As a within-subject control condition, the CIT was also applied without an additional task. The parallel task did not influence the mean differences of the physiological measures of the mock-crime-related probe and the irrelevant items. This finding might possibly be due to the fact that the applied parallel task induced a tonic rather than a phasic mental activity, which did not influence differential responding to CIT items. No physiological evidence for an interaction between the parallel task and sub-processes of deception (e.g. inhibition) was found. Subjects' performance in the Go/No-go parallel task did not contribute to the detection of concealed information. Generalizability needs further investigations of different variations of the parallel task.
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Perceiving a first target stimulus (T1) in a rapid serial visual presentation stream results in a transient impairment in detecting a second target (T2). This "attentional blink" is modulated by the emotional relevance of T1 and T2. The present experiment examined the neural underpinnings of the emotional modulation of the attentional blink. Behaviorally, the attentional blink was reduced for emotional T2 while emotional T1 led to a prolonged attentional blink. Using functional magnetic resonance imaging, we observed amygdala activation associated with the reduced attentional blink for emotional T2 in the face of neutral T1. The prolonged attentional blink following emotional T1 was correlated with enhanced activity in a cortical network including the anterior cingulate cortex, the insula and the orbitofrontal cortex. These results suggest that brain areas previously implicated in rather reflexive emotional reactions are responsible for the reduced attentional blink for emotional T2 whereas neural structures previously related to higher level processing of emotional information mediate the prolonged attentional blink following emotional T1.
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Facilitated detection of threatening visual cues is thought to be adaptive. In theory, detection of threat cues should activate the amygdala independently from allocation of attention. However, previous studies using emotional facial expressions as well as phobic cues yielded contradictory results. We used fMRI to examine whether the allocation of attention to components of superimposed spider and bird displays modulates amygdala activation. Nineteen spider-phobic women were instructed to identify either a moving or a stationary animal in briefly presented double-exposure displays. Amygdala activation followed a dose-response relationship: Compared to congruent neutral displays (two birds), amygdala activation was most pronounced in response to congruent phobic displays (two spiders) and less but still significant in response to mixed displays (spider and bird) when attention was focused on the phobic component. When attention was focused on the neutral component, mixed displays did not result in significant amygdala activation. This was confirmed in a significant parametric graduation of the amygdala activation in the order of congruent phobic displays, mixed displays with attention focus on the spider, mixed displays with focus on the bird and congruent neutral displays. These results challenge the notion that amygdala activation in response to briefly presented phobic cues is independent from attention.
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RATIONALE: Biased processing of drug-associated stimuli is believed to be a crucial feature of addiction. Particularly, an attentional bias seems to contribute to the disorder's maintenance. Recent studies suggest differential effects for stimuli associated with the beginning (BEGIN-smoking-stimuli) or the terminal stage of the smoking ritual (END-smoking-stimuli), with the former but not the later evoking high cue-reactivity. OBJECTIVE: The current study investigated the neuronal network underlying an attentional bias to BEGIN-smoking-stimuli and END-smoking-stimuli in smokers and tested the hypothesis that the attentional bias is greater for BEGIN-smoking-stimuli. METHODS: Sixteen non-deprived smokers and 16 non-smoking controls participated in an fMRI study. Drug pictures (BEGIN-smoking-stimuli, END-smoking-stimuli) and control pictures were overlaid with geometrical figures and presented for 300 ms. Subjects had to identify picture content (identification-task) or figure orientation (distraction-task). The distraction-task was intended to demonstrate attentional bias. RESULTS: Behavioral data revealed an attentional bias to BEGIN-smoking-stimuli but not to END-smoking-stimuli in both groups. However, only smokers showed mesocorticolimbic deactivations in the distraction-task with BEGIN-smoking-stimuli. Importantly, these deactivations were significantly stronger for BEGIN- than for END-smoking-stimuli and correlated with the attentional bias score. CONCLUSIONS: Several explanations may account for missing group differences in behavioral data. Brain data suggest smokers using regulatory strategies in response to BEGIN-smoking-stimuli to prevent the elicitation of motivational responses interfering with distraction-task performance. These strategies could be reflected in the observed deactivations and might lead to a performance level in smokers that is similar to that of non-smokers.
Erkunden
Team
- Vaitl (4)
Eintragsart
Sprache
- Englisch (4)
Thema
- Attention/*physiology
- Adaptation, Physiological/physiology (1)
- Adult (4)
- Amygdala/physiology (1)
- Amygdala/*physiopathology (1)
- Analysis of Variance (1)
- Animals (1)
- Arousal/physiology (1)
- Behavior, Addictive/*physiopathology (1)
- Blinking/*physiology (1)
- Brain Mapping/methods/*psychology (1)
- Brain/physiology (1)
- Cerebral Cortex/physiology (1)
- Cerebral Cortex/*physiopathology (1)
- Choice Behavior/*physiology (1)
- Cues (1)
- *Deception (1)
- Emotions/*physiology (1)
- Female (3)
- Fixation, Ocular/physiology (1)
- Functional Laterality/physiology (1)
- Galvanic Skin Response/physiology (2)
- Heart Rate/physiology (1)
- Humans (4)
- Image Processing, Computer-Assisted (1)
- *Inhibition, Psychological (1)
- Intention (1)
- Limbic System/*physiopathology (1)
- Logistic Models (1)
- Magnetic Resonance Imaging (2)
- Magnetic Resonance Imaging/methods/psychology (1)
- Male (3)
- Nerve Net/*physiology (1)
- Neural Inhibition/*physiology (1)
- Neural Pathways/physiopathology (1)
- Perceptual Masking/*physiology (1)
- Phobic Disorders/*physiopathology (1)
- Photic Stimulation (2)
- Photic Stimulation/methods (1)
- Problem Solving (1)
- Reaction Time/physiology (2)
- Reference Values (1)
- Smoking/*physiopathology/psychology (1)
- Spiders (1)
- Statistics, Nonparametric (1)
- Visual Perception/physiology (1)
- Visual Perception/*physiology (1)
- Young Adult (2)