Biological psychology
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Biological psychology · Dec 2003
Signal characteristics of spontaneous facial expressions: automatic movement in solitary and social smiles.
The assumption that the smile is an evolved facial display suggests that there may be universal features of smiling in addition to the basic facial configuration. We show that smiles include not only a stable configuration of features, but also temporally consistent movement patterns. ⋯ Both onsets and offsets had dynamic properties similar to automatically controlled movements, with a consistent relation between maximum velocity and amplitude of lip corner movement in smiles from two distinct contexts. Despite the effects of individual and social factors on facial expression timing overall, consistency in onset and offset phases suggests that portions of the smile display are relatively stereotyped and may be automatically produced.
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Biological psychology · Jul 2003
Comparative StudyPhysical activity does not disturb the measurement of startle and corrugator responses during affective picture viewing.
Healthy college females (n=24) completed counterbalanced conditions of 20 min of very low and low intensity cycling exercise and seated rest. Startle and corrugator supercilii responses, and baseline orbicularis oculi and corrugator supercilii electromyographic (EMG) activity, were measured during each exercise condition while participants viewed pleasant, neutral and unpleasant pictures. ⋯ In conclusion, low intensity physical activity is not sufficient to alter emotional responsiveness as assessed by the acoustic startle eyeblink response and corrugator supercilii EMG responses during the viewing of pleasant, neutral, and unpleasant pictures. Despite modestly increased baseline EMG levels, reliable startle and corrugator EMG responses can be obtained in healthy college females during picture viewing while performing low intensity cycling exercise.
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Biological psychology · Feb 2002
Addressing the specificity of affective startle modulation: fear versus disgust.
Previous research is equivocal regarding whether startle reflex eyeblink is specifically sensitive to the emotion of fear, or is more generally influenced by the valence dimension of emotion. Thirty-five undergraduate participants (17 male) viewed 60 pictures from five affective categories (pleasant, neutral, fear, disgust-blood, and disgust-other). Bilateral eyeblink EMG responses to acoustic startle probes were assessed during 2/3 of picture presentations, and 1/3 of intertrial intervals. ⋯ In fact, women, but not men, had larger startles during disgust compared with fear pictures. Both corrugator and levator EMG responses were greater to disgust than fear stimuli. These findings limit the generalizability of corrugator as an index of all negative emotions and extend evidence for the specificity of levator to disgust.
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Biological psychology · Jul 2000
Comparative StudyOperant conditioning of left-hemispheric slow cortical potentials and its effect on word processing.
This study investigated whether language-related cognitive processes can be modified by learned modulation of cortical activity. Study participants received feedback of slow cortical potentials (SCPs) recorded above left-hemispheric language cortices and were reinforced for producing negative and positive shifts upon two different discriminative stimuli. In all subjects who achieved reliable control of left-hemispheric brain responses, substantial modification of word processing was observed. ⋯ This argues against a global effect related to perception, visuo-spatial attention, or motor processes. We conclude that linguistic processes can be influenced by modification of cortical activity due to operant conditioning. In closing, tentative explanations of the present results based on theories of language and attention processes are being discussed.
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Biological psychology · Sep 1998
Randomized Controlled Trial Clinical TrialCardiorespiratory effects of breathing and relaxation instruction in myocardial infarction patients.
The effect of individual instruction in relaxation and breathing, additional to an exercise training program, was investigated in 76 post-myocardial infarction patients after rehabilitation and at 3 months follow-up. Respiration rate (RR), heart rate (HR) and respiratory sinus arrhythmia (RSA) were the outcome variables used to compare experimental (exercise plus relaxation) and control (exercise without relaxation) groups. HR and RR decreased slightly during 20-min sessions of supine measurement. ⋯ This effect was also associated with a slower RR and became marginally significant when RR was statistically controlled for. We conclude that the relaxation intervention induced a slower breathing pattern which was associated with beneficial effects on resting HR and RSA. Further study is warranted to clarify the degree to which reduced respiration rate is an indicator of lower sympathetic arousal or merely a concomitant of the learned breathing technique.