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Biomedical subjects

N A Fox

Publications and source records attributed to N A Fox.

64 records · Page 4Linked to original sources
PubMed1989

Frontal brain asymmetry predicts infants' response to maternal separation.

Examined whether certain features of infant temperament might be related to individual differences in the asymmetry of resting frontal activation. EEG was recorded from the left and right frontal and parietal scalp regions of 13 normal 10-month-old infants. Infant behavior was then observed during a brief period of maternal separation. Those infants who cried in response to maternal separation showed greater right frontal activation during the preceding baseline period compared with infants who did not cry. Frontal activation asymmetry may be a state-independent marker for individual differences in threshold of reactivity to stressful events and vulnerability to particular emotions.

Anxiety, Separation↗
PubMed1989

Patterns of care and expenditures by California Medicaid for peptic ulcer and other acid-related diseases.

We examined California Medicaid (Medi-Cal) service use and expenditures for peptic ulcer and other acid-related diseases during the 10-year period fiscal year (FY) 1976-1985. Between FY 1976 and FY 1980, hospitalizations rose irregularly, operations declined by 37%, endoscopies tripled, physician visits fluctuated from year to year, antacid prescriptions increased by 36%, and anticholinergic medication use was stable. From FY 1981 to FY 1985, hospitalizations declined by 52%, operations by 91%, endoscopies by 45%, physician visits by 30%, antacid use by 12%, and anticholinergic medication use by 48%. H2 antagonists were allowed onto Medi-Cal formulary near the end of FY 1980, and use rose sharply through 1985. Similar results were found across specific gastrointestinal (GI) diagnoses. Total payments for acid-related conditions were essentially stable during FY 1976-1980 period, although, for individual services, utilization and expenditures did not always move in the same direction. For example, declining operations rates and stable expenditures were found. However, during FY 1981-85, changes in rates of service use were generally matched by similar changes in total expenses for that service. For example, the 40% reduction in rate of endoscopies was accompanied by a near 50% decline in payments. Overall expenditures for all acid-related diagnoses fell by nearly 28% between 1981 and 1985. We concluded that the introduction of H2 antagonists had important positive clinical effects on all studied acid-related GI diagnoses.

California↗
PubMed1986

Taste-elicited changes in facial signs of emotion and the asymmetry of brain electrical activity in human newborns.

Recent evidence suggests that frontal brain electrical activity reveals asymmetries in activation in response to positive vs negative affective stimuli. This study was designed to evaluate whether this asymmetry is present at birth. Newborn infants were presented with water followed by a sucrose solution and then by a citric acid solution. Facial expression was videotaped during the presentation of the liquids and EEG was recorded from the frontal and parietal scalp regions on the left and right side. Usable EEG data were obtained from 16 newborn infants in response to these taste conditions. Videotaping of facial expression in response to these stimuli indicated the presence of disgust during both water (the first taste introduced) and citric acid. EEG was Fourier Transformed and power in the 1-3, 3-6 and 6-12 Hz bands was computed. The findings revealed that the water condition produced reductions in right-hemisphere power in the two higher frequency bands in both the scalp regions compared with the other two conditions. The sucrose condition produced greater relative left-sided activation in both regions compared with the water condition. These data, in conjunction with our previous findings of asymmetries in 10-month-old infants, indicate that stimulus-elicited affective asymmetries in brain electrical activity are present at birth.

Citrates↗
PubMed1985

The relation between neonatal heart period patterns and developmental outcome.

Developmental psychophysiologists have long been interested in a means for evaluating infants at risk for cognitive disabilities. The current research addressed the utility of a noninvasive measure of cardiac vagal tone in predicting developmental outcome. At 40 weeks conceptional age, 3 min of resting EKG were recorded from 80 infants. Four groups of infants were evaluated: prematures who had no medical complications in the postnatal period; prematures who experienced respiratory distress syndrome during the postnatal period; term infants who experienced birth asphyxia during labor and/or postdelivery; and healthy term infants. The mental scale of the Bayley Scales of Mental Development was administered at 8 and 12 months conceptional age. Heart period data were analyzed to derive mean heart period, heart period variability, and estimates of vagal tone for each subject. Analyses of the relationship between the heart period variables and 8- and 12-month outcome (i.e., Bayley Scales) indicated that infants with high vagal tone at 40 weeks conceptional age always had positive developmental outcome at both eight and 12 months of age. Infants with low vagal tone had varied outcomes. Measures of medical complications and other measures of heart period variability were not related to developmental outcome. The results suggest that measurement of cardiac vagal tone may provide an important means for assessing risk in birth stressed populations.

Asphyxia Neonatorum↗
PubMed1983

Maturation of autonomic control in preterm infants.

In order to investigate the development of autonomic control and its relation to postnatal illness, healthy term, healthy preterm, and preterm infants who had recovered from respiratory distress syndrome (RDS) were seen around the expected date of their birth, 40 weeks conceptional age (C.A.), and again at 3 months conceptional age. Three minutes of resting EKG were collected at each age point while the infant was in a quiet, alert state. Measures of resting heart period and heart period variability were derived. Results revealed the influence of maturity and illness on autonomic activity. RDS and healthy preterm infants, at 40 weeks C.A. exhibited a pattern of small heart period compared to healthy term. RDS preterm infants at 40 weeks C.A. exhibited less overall variability than either healthy group and across age displayed less short-term variability than the healthy infants. The data suggest that autonomic activity during the early months of life may be affected by both prematurity and postnatal illness. The significance of these data in understanding term/preterm differences in the neonatal period is discussed.

Autonomic Nervous System↗
PubMed1983

The relationship between neonatal characteristics and three-month mother-infant interaction in high-risk infants.

The behavior of 4 groups of infants--healthy term, healthy preterm, sick preterm, and sick full-term--was assessed in the neonatal period using the Neonatal Behavioral Assessment Scale (NBAS). At 3 months postterm, infants and their mothers were observed and videotaped in a free-play session. Both the NBAS and mother-infant interaction data were analyzed to assess the effects of maturity (term vs. preterm), illness (sick vs. healthy), and their interaction. Results revealed that illness of the infant affected both NBAS performance and maternal behavior during the interaction at 3 moths. Infants who were ill performed poorly on the NBAS orientation dimension; this dimension was found to be significantly associated with maternal and infant behaviors at 3 months. These data demonstrate an association between early infant characteristics and subsequent mother and child interactive behaviors. They also identify postnatal illness as an important influence on the development of the mother-infant dyad.

Asphyxia Neonatorum↗
PubMed1982

Asymmetrical brain activity discriminates between positive and negative affective stimuli in human infants.

Ten-month-old infants viewed videotape segments of an actress spontaneously generating a happy or sad facial expression. Brain activity was recorded from the left and right frontal and parietal scalp regions. In two studies, infants showed greater activation of the left frontal than of the right frontal area in response to the happy segments. Parietal asymmetry failed to discriminate between the conditions. Differential lateralization of the hemispheres for affective processes seems to be established by 10 months of age.

Affect↗
PubMedDate not supplied

Localising maxillary canines using dental panoramic tomography.

Impacted maxillary canine teeth occur in about 2% of the population. Late detection of palatal canines may have treatment implications for the patient and medicolegal implications for the dental practitioner. Dental panoramic tomograms (DPT) are widely taken in practice. Image formation in dental panoramic tomography results in relative magnification of objects placed palatal to the image layer and relative diminution of objects buccal to it. This provides a possible means of bucco-palatal localisation of teeth. The aim of this study was assess the validity of DPTs in locating ectopic canines using the vertex occlusal view (VO) as the gold standard. One hundred pairs of radiographs showing 139 ectopic canines were examined. Using the DPT, it was possible to accurately predict the position of a palatally displaced crown in about 80% of cases. The DPT alone is not sufficient for canine localisation, but clinical evidence and suggestion of ectopic positioning on a DPT should warrant further radiographic investigation. Careful interpretation of a radiograph widely used in practice may lead to earlier detection of palatal canines.

Child↗
PubMedDate not supplied

Continuity and discontinuity of behavioral inhibition and exuberance: psychophysiological and behavioral influences across the first four years of life.

Four-month-old infants were screened (N = 433) for temperamental patterns thought to predict behavioral inhibition, including motor reactivity and the expression of negative affect. Those selected (N = 153) were assessed at multiple age points across the first 4 years of life for behavioral signs of inhibition as well as psychophysiological markers of frontal electroencephalogram (EEG) asymmetry. Four-month temperament was modestly predictive of behavioral inhibition over the first 2 years of life and of behavioral reticence at age 4. Those infants who remained continuously inhibited displayed right frontal EEG asymmetry as early as 9 months of age while those who changed from inhibited to noninhibited did not. Change in behavioral inhibition was related to experience of nonparental care. A second group of infants, selected at 4 months of age for patterns of behavior thought to predict temperamental exuberance, displayed a high degree of continuity over time in these behaviors.

Acoustic Stimulation↗