International journal of psychophysiology : official journal of the International Organization of Psychophysiology
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Int J Psychophysiol · Aug 2007
Stimulus intensity affects early sensory processing: sound intensity modulates auditory evoked gamma-band activity in human EEG.
We studied the effect of different sound intensities on the auditory evoked gamma-band response (GBR). Previous studies observed oscillatory gamma activity in the auditory cortex of animals and humans. For the visual modality, it has been demonstrated that the GBR can be modulated by top-down (attention, memory) as well as bottom-up factors (stimulus properties). ⋯ The results demonstrate a distinct dependency between sound intensity and gamma-band oscillations. Future experiments that investigate the relationship between auditory evoked GBRs and higher cognitive processes should therefore select stimuli with an adequate sound intensity and control this variable to avoid confounding effects. In addition, it seems that gamma-band activity is more sensitive to exogenous stimulus parameters than evoked potentials.
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Int J Psychophysiol · Apr 2007
ReviewA breakthrough in neuroscience needs a "Nebulous Cartesian System" Oscillations, quantum dynamics and chaos in the brain and vegetative system.
The Cartesian System is a fundamental conceptual and analytical framework related and interwoven with the concept and applications of Newtonian Dynamics. In order to analyze quantum processes physicist moved to a Probabilistic Cartesian System in which the causality principle became a probabilistic one. This means the trajectories of particles (obeying quantum rules) can be described only with the concept of cloudy wave packets. ⋯ Another metaphor to consider within the oscillatory approach of the NCS is the "string theory". We also emphasize that fundamental steps should be undertaken in order to create the own dynamical framework of the brain-body-mind incorporation; suggestions or metaphors from physics and mathematics are useful; however, the grammar of the brains intrinsic language must be understood with the help of a new biologically founded, adaptive-probabilistic Cartesian system. This new Cartesian System will undergo mutations and transcend to the philosophy of Henri Bergson in parallel to the Evolution theory of Charles Darwin to open gateways for approaching the brain-body-mind problem.
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Int J Psychophysiol · Jan 2007
Neuroticism-Anxiety, Impulsive-Sensation Seeking and autonomic responses to somatosensory stimuli.
This study focused on autonomic responding in participants who scored high vs. low on the Neuroticism-Anxiety (N-Anx) and Impulsive-Sensation Seeking (Imp-SS) dimensions of the Zuckerman-Kuhlman Personality Questionnaire--Form III. Participants were presented with series of tones (standards, deviants and novels) and they received a mild electric shock (one, two or three pulses) at each 15th tone. Resting pre-stimulus skin conductance level (SCL) and heart rate (HR) level was recorded, as well as the skin conductance response (SCR) and (anticipatory) HR response to the electric stimuli. ⋯ High Imp-SS had a lower pre-stimulus SCL and smaller SCRs to deviant stimuli compared to low Imp-SS participants. Additionally, their HR acceleration was smaller in anticipation of the first and the deviant tones whereas their deceleratory response was larger relative to the HR changes observed for the low Imp-SS participants. This pattern of findings was taken to suggest that high Imp-SS participants are more arousable and less prone to defensive reactions to novel or aversive stimulation.
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Int J Psychophysiol · Jan 2007
Comparative StudyAffective modulation of autonomic reactions to noxious stimulation.
Research suggests that emotion modulates spinal nociception and pain; however, there is limited evidence that other objective, nociceptive reactions are modulated. This study examined the impact of affective picture-viewing on autonomic reactions (skin conductance response, heart rate acceleration) resulting from noxious electric stimulations to the sural nerve. Pictures varying in affective valence (unpleasant, neutral, pleasant) were presented during which noxious stimulations were delivered. ⋯ Specifically, reactions were smaller during pleasant pictures than unpleasant pictures, although unpleasant pictures did not result in significant facilitation relative to neutral pictures. The valence linear trend explained 26% of the variance in the multivariate combination of the reactions, suggesting emotion does modulate autonomic reactions to nociception. These results suggest that SCR and HR acceleration are outcomes that can be assessed together with NFR and pain report during picture-viewing to study affective modulation of spinal (NFR), supraspinal (SCR, HR acceleration), and subjective (pain report) nociceptive reactions.
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Int J Psychophysiol · Jan 2007
The development of stop-signal and Go/Nogo response inhibition in children aged 7-12 years: performance and event-related potential indices.
The present study examined the development of response inhibition during the Stop-signal and Go/Nogo tasks in children using performance and ERP measures. Twenty-four children aged 7 to 12 years completed both tasks, each with an auditory Nogo/Stop-signal presented on 30% of trials. On average, response inhibition was more difficult in the Stop-signal than Go/Nogo task. ⋯ N1 and P3 amplitude in the parietal region increased with age for Stop-signals. An age-related reduction in P3 latency to Nogo stimuli correlated significantly with reduced RT and variability in Go responding, indicating a relationship between efficient Nogo and Go processing. Together the behavioural and ERP results suggest little development of the response inhibition process as measured via the Stop-signal and Go/Nogo tasks across the 7 to 12 year age range, while response execution processes develop substantially.