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Biomedical subjects

S W Porges

Publications and source records attributed to S W Porges.

At least 73 records · Page 4Linked to original sources
PubMed1984

Physiologic correlates of attention: a core process underlying learning disorders.

If attention disorders are common to many behavioral pathologies, is it possible that these pathologies have a common physiologic substrate? To approach this question, this article organizes the literature to deal with aspects of (a) the definition of attention, (b) individual differences in physiologic correlates of attention, and (c) speculations regarding potential physiologic processes mediating attention.

Animals↗
PubMed1984

Psychopathology in infancy and early childhood: clinical perspectives on the organization of sensory and affective-thematic experience.

The developmental-structuralist approach to psychopathology in infants and young children involves studying adaptive and maladaptive patterns at each level of "experimental organization" from the early sensory, motor, and affective-thematic organizations to the later representational ones. Psychopathology may be related to defects or constrictions at each organizational level, including the representational or symbolic realm, without underlying vulnerabilities in earlier levels of organization, and may also involve the presumed "underbelly" of the personality, those central nervous system organizations that have to do with filtering and processing of perceptions and experience (the early sensory and affective-thematic organizations). The most severe psychopathologies, it will be suggested, occur where there are compromises in both the early sensory and affective-thematic and later representational organizations. Early limitations in "processing" animate or inanimate experiences may, in many instances, be highly specific and reversible rather than global. The early detection of sensory and affective-thematic organizational compromises, followed by approaches that facilitate phase-specific "essential experiences" through intact sensory pathways and the remediation of compromised ones, may provide a systematic base for possible preventive intervention approaches.

Arousal↗
PubMed1982

The ontogeny of heart period patterning in the rat.

Heart period, heart period variability, and respiration frequency were observed and compared longitudinally in rats from birth to 24 days of age. In addition, V, a quantification of respiratory sinus arrhythmia derived via spectral analysis of the heart period pattern, was observed. It was hypothesized that these heart period parameters would be differentially sensitive to the neural control of the heart and would, therefore, reflect different developmental patterns. Heart period and heart period variability indicated developmental patterns consistent with the literature. The ontogeny of V suggests that it may represent the developmental pattern of tonic vagal influences on the heart.

Aging↗
PubMed1977

Cardiac and respiratory responses during visual search in nonretarded children and retarded adolescents.

The relationship between physiological response patterns and mental competence was investigated by evaluating heart rate and respiratory responses during a sustained visual-search task in nonretarded grade school children and retarded adolescents. The findings support the contention that, during tasks demanding sustained attention, retarded relative to nonretarded individuals exhibit physiological responses that parallel their poor performance. Consistent with previous research with nonretarded adults, the nonretarded grade school children exhibited a suppression of respiratory and heart-rate variability during attention-demanding tasks. In contrast, the retarded adolescents exhibited increases in respiratory and heart-rate variability. These qualitative differences in physiological and behavioral responses, observed during sustained attention, may be viewed as a manifestation of retarded adolescents' defective nervous system.

Adolescent↗
PubMed1975

The influences of methylphenidate on heart rate and behavioral measures of attention in hyperactive children.

Reaction-time performance and heart-rate responses associated with attention were used to assess the hyperactive child's attentional deficit and his response to methylphenidate. Attentional deficits shown by long response latencies were reflected in heart-rate responses theoretically incompatible with sustained attention. Subjects exhibiting the greatest attentional deficit displayed the most favorable response to methylphenidate in both reaction-time performance and physiological measures. However, subjects who showed the greatest improvement in social behavior were those who showed the least improvement in reaction-time performance.

Attention↗
PubMedDate not supplied

Vagal tone regulation during sustained attention in boys exposed to opiates in utero.

Attention and learning problems among children exposed to opiates in utero have been previously reported but are difficult to interpret due to imprecise measurement and inadequate control of postnatal factors. In this study, we used a behavior-based measure of attention (continuous-performance tasks) and a physiological index of sustained attention (cardiac vagal tone) to measure more precisely the process of sustained attention. Boys, aged 7 to 12, exposed to opiates in utero, were compared to boys whose mothers began using illicit substances after the child's birth (environmental controls), and boys whose mothers were non-drug users. This three-group design was intended to isolate in utero effects from postnatal environmental influences. Vagal tone, a measure of heart-rate variability sensitive to vagal influences on the heart, was measured pre- and postbaseline and during the three tasks of the Gordon Diagnostic System (Delay, Vigilance, and Distractibility). Vagal tone has been found to be sensitive to changes in environmental demand for sustained attention in infants, school-age children, and adults. Results indicated that when distractors were added to the vigilance task (Distractibility task), opiate-exposed boys failed to suppress vagal tone compared to both control groups. However, both the opiate-exposed boys and the environmental controls made fewer correct responses than non-drug-exposed controls on this task. These results indicate that normal physiological responses to increased attentional demand may be impaired in boys exposed in utero to opiates in this age range. However, the poor Distractibility scores of both the opiate-exposed and environmental controls suggests an important role of environmental influences on attentional performance.

Arousal↗
PubMedDate not supplied

Responses to laboratory psychosocial stress in postpartum women.

OBJECTIVE: Lactation has been associated with attenuated hormonal responses to exercise stress in humans. This study was designed to determine the effect of lactation on hypothalamic-pituitary-adrenal axis, autonomic nervous system, and anxiety responses to psychological stress. METHOD: The Trier Social Stress Test was administered to 24 lactating women, 13 postpartum nonlactating women, and 14 healthy control women in the early follicular phase of the menstrual cycle. Lactating women were stressed at least 40 minutes after last feeding their infant. RESULTS: ACTH, cortisol, heart rate, diastolic blood pressure, systolic blood pressure, and subjective anxiety ratings were all significantly increased in response to the psychological stress (all p <.0001). There were no differences among the three groups in any of these responses to the stress. However, postpartum nonlactating women did have a persistently higher systolic blood pressure and lower cardiac vagal tone than the lactating women and control subjects. In addition, the typical negative correlation between cardiac vagal tone and heart rate was consistently higher in lactating women than nonlactating postpartum women and controls, which suggests stronger vagal control of heart rate in lactating women. In addition, there was no change in oxytocin or allopregnanolone in response to the stress, and baseline oxytocin and allopregnanolone levels did not differ among the three groups. CONCLUSIONS: These results indicate that physiological and subjective responses to social stress are not attenuated in lactating women tested at least one hour after feeding their infant. However, enhanced vagal control of cardiac reactivity was observed in lactating women. In addition, postpartum women who did not lactate showed evidence of increased sympathetic and decreased parasympathetic nervous system tone.

Adult↗