ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1988.tb00947.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1988.tb00948.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTSkin conductance responses to a series of loud tones were measured bilaterally in 121 pairs of adult twins, 53 pairs reared together and 68 pairs reared apart. Subjects were given an absorbing task on which to focus their attention and instructed to ignore the meaningless tones. Rangecorrection eliminated hand and sex differences in SCR amplitude and also the correlation with age of this variable. For the combined group of 79 pairs of monozygotic (MZ) twins, the within‐pair correlations for Y‐intercept, the slope of the habituation curve, and the number of trials to habituation were near the limits of retest reliability for these variables. After range‐correction, the correlation for Y‐intercept for the 42 pairs of dizygotic (DZ) twins was about half the MZ value, suggesting that initial electrodermal reactivity is strongly genetic and can be interpreted according to a polygenic‐additive model. Biometric model testing indicated that stable individual differences in uncorrected SCR amplitude and in habituation slope are primarily determined by non‐additive genetic factors. About 40% of the total variance (and most of the stable variance) in number of trials to habituation is genetically determined. Co‐twins of MZ twins who were electrodermal nonresponders tended also to be hyporesponsive while co‐twins of DZ nonresponders tended to be

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1988.tb00949.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1988.tb00950.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTAlthough individual differences in sensation‐seeking are characterized by a wide range of differences in the expression of motor behavior, the psychophysiological correlates of these characteristics have not been extensively explored. In the present investigation the response characteristics of compound muscle action potentials, the H‐reflex and associated motor responses, were examined in young adult subjects who were administered the Sensation Seeking Scale (Zuckerman, 1979) and the Eysenck Personality Questionnaire (Eysenck&Eysenck, 1975). Variations in reflex responses were observed using two independent procedures. A paired stimulus method assessed the extent of reflex amplitude recovery at varying pulse intervals. A second method, termed homosynaptic depression, examined motoneuronal excitability in response to trains of pulses delivered at varying rates. The personality groups did not differ with respect to the intensity of stimulation required to elicit muscle action potentials or the nerve conduction velocities of those potentials. High disinhibition and high extraversion groups displayed reduced motoneuronal excitability as assessed by analysis of reflex recovery functions. For extraversion, similar effects were observed with the homosynaptic depression measure. These results demonstrate that individual differences in disinhibition and extraversion can be referred to discrete levels of CNS motor system activity. In this context, stimulus seeking behavior is not distinguished by a need for stimulation (initial hypoexcitability) but reflects instead reduced motor excitability which becomes evident once motoneuronal activity is initia

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1988.tb00951.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1988.tb00952.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTIt has been hypothesized that activation of the baroreceptor reflex arc, by its central nervous inhibitory effects, is involved in an operant learning mechanism of blood pressure elevation. The present study investigated the effects of mechanical stimulation of the baroreceptors in the carotid sinus on pain threshold and electrical brain activity in two groups of humans with different tonic blood pressure levels. In normotensives, baroreceptor stimulation lowered pain threshold as compared to a control condition, while borderline hypertensives tolerated more intense electric stimulation when baroreceptors were activated. A marked reduction of the contingent negative variation in anticipation of the aversive stimulation accompanied baroreceptor stimulation, probably a consequence of baroreceptor afferent impulses exerted via brainstem centers to cerebral cortex. The distribution of the potential change across the scalp depended on the tonic blood pressure, indicating differences in brain functioning between normotensives and borderline hypertensives.The present results suggest that the hypothesis of an operantly‐conditioned blood pressure elevation under stress may be valid only in subjects with a predisposition for essential hypertensio

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1988.tb00953.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTA recent study by Raine and Venables (1987) reported increased P3 amplitudes in antisocial adolescents, a replicable result indicating enhanced processing of task‐relevant events. The present study assesses whether adult psychopaths similarly show enhanced P3 amplitudes; latency of P3 recovery to baseline was also measured to assess Jutai et al.'s (1987) finding of sustained late positivity in psychopaths. EPs were measured at T3, T4, P3, and P4to targets and nontargets during a continuous performance task in 14 psychopathic and 14 nonpsychopathic top‐security prisoners. Psychopaths showed larger P3 amplitudes to targets relative to nontargets at parietal but not temporal sites, and larger P3 recovery times. Psychopaths also scored higher on WAIS subtests sensitive to parietal lobe functioning but not on non‐parietal subtests. No laterality effects were uncovered to support a left hemisphere dysfunction theory of psychopathy. It is argued that this evidence for proficient information‐processing on parietal‐related tasks may underlie clinical reports of enhanced short‐term attentional ability in

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1988.tb00954.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTThis study investigated heart rate (HR) acceleration and its relationship to serum cholesterol, triglycerides, and blood pressure reactivity in a group of men with unmedicated mild hypertension. Each man's cardiovascular responses were monitored as he performed the Stroop Color Word Interference test and played the Pac Man Videogame. In comparison to their low HR accelerator counterparts, high HR accelerators manifested greater systolic and diastolic blood pressure responses during behavioral challenge. Moreover, high HR accelerators exhibited higher levels of serum cholesterol and triglycerides than low HR accelerators, even though these determinations were made from blood drawn during the clinic visit that preceded the clinic visit where cardiovascular reactivity was assessed. Heart rate acceleration and its positive association with serum lipids, as well as its role as a potential individual difference relevant to the profiling of persons at greater risk for the development of atherosclerosis were discussed.

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1988.tb00955.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1988.tb00956.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY