Event-related brain potentials reveal anomalies in temporal processing of faces in autism spectrum disorder

BACKGROUND: Individuals with autism exhibit impairments in face recognition, and neuroimaging studies have shown that individuals with autism exhibit abnormal patterns of brain activity during face processing. The current study examined the temporal characteristics of face processing in autism and their relation to behavior. METHOD: High-density event-related brain potentials (ERPs) were recorded to images of faces, inverted faces, and objects from 9 individuals with autism spectrum disorder (15-42 years old) and 14 typical individuals (16-37 years old). RESULTS: With respect to a face-sensitive ERP component (N170), individuals with autism exhibited longer N170 latencies to faces than typical individuals but comparable latencies to objects. Typical individuals exhibited longer N170 latencies to inverted as compared to upright faces, whereas individuals with autism did not show differences in N170 latency to upright versus inverted faces. Neural speed of face processing, as reflected in N170 latency, correlated with performance on a face recognition task for individuals with autism. CONCLUSIONS: These data provide evidence for slowed neural speed of face processing in autism and highlight the role of speed of processing in face processing impairments in autism.     

Recognition of own-race and other-race faces by three-month-old infants

BACKGROUND: People are better at recognizing faces of their own race than faces of another race. Such race specificity may be due to differential expertise in the two races. METHOD: In order to find out whether this other-race effect develops as early as face-recognition skills or whether it is a long-term effect of acquired expertise, we tested face recognition in 3-month-old Caucasian infants by conducting two experiments using Caucasian and Asiatic faces and a visual pair-comparison task. We hypothesized that if the other race effect develops together with face processing skills during the first months of life, the ability to recognize own-race faces will be greater than the ability to recognize other-race faces: 3-month-old Caucasian infants should be better at recognizing Caucasian faces than Asiatic faces. If, on the contrary, the other-race effect is the long-term result of acquired expertise, no difference between recognizing own- and other-race faces will be observed at that age. RESULTS: In Experiment 1, Caucasian infants were habituated to a single face. Recognition was assessed by a novelty preference paradigm. The infants' recognition performance was better for Caucasian than for Asiatic faces. In Experiment 2, Caucasian infants were familiarized with three individual faces. Recognition was demonstrated with both Caucasian and Asiatic faces. CONCLUSIONS: These results suggest that (i) the representation of face information by 3-month-olds may be race-experience-dependent (Experiment 1), and (ii) short-term familiarization with exemplars of another race group is sufficient to reduce the other-race effect and to extend the power of face processing (Experiment 2).     

Reflex modification audiometry: assessment of acoustic sensory processing in the term neonate

Behavioral and physiological work in animals and adult humans have established the sensitivity of various procedures and allowed delineation of the neuroanatomical pathways involved in sensory processing. Herein we used the glabellar reflex and reflex modification procedures to assess acoustic sensory processing capabilities in the term newborn infant. The eyeblink-eliciting device consisted of a miniature solenoid which could deliver a controlled tap. A photoreflective densitometer attached to a TDH-39 earphone assessed the eyeblinks. A total of 98 term infants was studied to determine how a response to a reflex-eliciting event (tap) was modified (either augmented or inhibited) by a mild exteroceptive stimulus (tone) which was presented at an appropriate lead interval. Ninety adult subjects were given identical testing procedures and their data were compared to that of the infants. The results of this study showed that newborn infants reliably exhibited an eyeblink response after a tap to the glabella. With fixed intensity tones, frequencies from 1 to 4 kHz produced equivalent amounts of reflex augmentation in infants and adult subjects. Blink amplitude increased as a function of increased tap and tone intensity in both infants and adults. State change was shown to affect the amplitude of the reflexive eyeblink, but not the augmentation effect. However, neonates failed to show inhibition to either acoustic lactile stimuli at an interstimulus interval that produced significant inhibition in the adult. These data indicate that reflex modification procedures provide an objective assessment of acoustic sensory processing in the term neonate.(ABSTRACT TRUNCATED AT 250 WORDS)     

V-shaped pillows and unsafe infant sleeping

To investigate the possibility that adult size V-shaped pillows may be associated with accidental asphyxial deaths in infants.

Methodology:

Review was undertaken of all cases of sudden infant death presenting to the Women's and Children's Hospital in Adelaide involving infants who had been found on adult size V-shaped pillows.

Results:

Four cases of sudden infant death were found in which infants were found sleeping on V-shaped pillows. All of the deaths had occurred in 1995. In two of the cases the pillows were considered to be implicated in the cause of death as the potential for obstruction of the infants' airways could be demonstrated on death scene reconstruction.

Conclusion:

Adult size V-shaped pillows may be unsafe for use in small infants who may accidentally suffocate if trapped between the two arms, or under, the pillow. The use of such pillows to maintain the body position of sleeping infants should be discouraged.     

孤独症谱系障碍儿童辨认基本情绪面孔早期加工阶段的异常特征

目的 探讨孤独症谱系障碍（ASD）儿童对基本情绪面孔的辨认能力以及在辨认基本情绪面孔的早期加工阶段可能存在的异常特征。方法 以中国人物静态表情图片为刺激材料,分析25名ASD儿童与22名年龄、性别匹配的普通儿童对4种基本情绪（害怕、高兴、生气和伤心）面孔的文字标签识别能力及脑电反应。结果 在总表情和害怕面孔的脑电反应中,对照组表现出大脑左侧颞区的N170潜伏期较右侧短（P < 0.05）,而ASD组对情绪面孔的N170反应未显示出对照组的这种差异;且在总表情、害怕和高兴面孔下,ASD组左侧颞区的N170潜伏期较对照组长（P < 0.05）,而在生气和害怕表情下也表现出右侧颞区的N170潜伏期长于对照组的趋势。结论 ASD儿童对基本情绪面孔在早期加工阶段的感知速度总体上偏慢,且对情绪面孔早期加工的偏侧化模式可能存在异常。     

The influence of a pacifier on infants' arousals from sleep

OBJECTIVE: The risk of sudden infant death during sleep was postulated to decrease with the use of a pacifier and by conditions facilitating arousals from sleep. We evaluated the influence of a pacifier on arousal from sleep in healthy infants. STUDY DESIGN: Fifty-six healthy infants were studied with polygraphy during 1 night; 36 infants used a pacifier regularly during sleep, and 20 never used a pacifier. Thumb users or occasional pacifier users were not included in the study. The infants were recorded at a median age of 10 weeks (range 6 to 19 weeks). To evaluate auditory arousal thresholds, the infants were exposed to white noise of increasing intensity during rapid eye movement sleep. RESULTS: Polygraphic arousals occurred at significantly lower auditory stimuli in pacifier users than in nonusers (P =.010). Compared with nonusers, pacifier users were more frequently bottle-fed than breast-fed (P =. 036). Among infants sleeping without a pacifier, breast-fed infants had lower auditory thresholds than bottle-fed infants (P =.049). CONCLUSIONS: Infants using pacifiers during sleep had lower auditory arousal thresholds than those who did not use a pacifier during sleep. Breast-feeding could be a further factor contributing to lower arousal thresholds. These findings could be relevant to the occurrence of sudden infant deaths during sleep.     

The effects of maternal social phobia on mother-infant interactions and infant social responsiveness

BACKGROUND: Social phobia aggregates in families. The genetic contribution to intergenerational transmission is modest, and parenting is considered important. Research on the effects of social phobia on parenting has been subject to problems of small sample size, heterogeneity of samples and lack of specificity of observational frameworks. We addressed these problems in the current study. METHODS: We assessed mothers with social phobia (N = 84) and control mothers (N = 89) at 10 weeks in face-to-face interactions with their infants, and during a social challenge, namely, engaging with a stranger. We also assessed mothers with generalised anxiety disorder (GAD) (N = 50). We examined the contribution to infant social responsiveness of early infant characteristics (neonatal irritability), as well as maternal behaviour. RESULTS: Mothers with social phobia were no less sensitive to their infants during face-to-face interactions than control mothers, but when interacting with the stranger they appeared more anxious, engaged less with the stranger themselves, and were less encouraging of the infant's interaction with the stranger; infants of index mothers also showed reduced social responsiveness to the stranger. These differences did not apply to mothers with GAD and their infants. Regression analyses showed that the reduction in social responsiveness in infants of mothers with social phobia was predicted by neonatal irritability and the degree to which the mother encouraged the infant to interact with the stranger. CONCLUSIONS: Mothers with social phobia show specific parenting difficulties, and their infants show early signs of reduced social responsiveness that are related to both individual infant differences and a lack of maternal encouragement to engage in social interactions.     

Are numerical impairments syndrome specific? Evidence from Williams syndrome and Down's syndrome

BACKGROUND: Several theorists maintain that exact number abilities rely on language-relevant processes whereas approximate number calls on visuo-spatial skills. We chose two genetic disorders, Williams syndrome and Down's syndrome, which differ in their relative abilities in verbal versus spatial skills, to examine this hypothesis. Five experiments assessed number skills in these two genetic syndromes and in their mental age (MA) and chronological age (CA) matched controls. METHODS: Experiment 1 used a preferential looking paradigm with infants and toddlers to measure sensitivity to changes in numerosity. Experiment 2 measured reaction times in older children and adults in a numerosity comparison task with dots in a random pattern. Experiment 3 comprised a number battery that measured various forms of counting and simple arithmetic. RESULTS: The WS infants displayed a level of performance equal to that of their CA-controls, whereas the DS infants failed to reach even the level of their MA-controls. By contrast, the older DS children and adults outstripped the older WS group in their numerosity abilities, with different patterns of errors in the two clinical groups. CONCLUSIONS: Differences in the infant and adult number phenotypes between these two genetic disorders are discussed with reference to the processing styles used by each group and how these might impact on their developmental trajectories. Theoretically, we highlight our contention that one cannot infer the infant starting state from the adult end state. Rather, the development process itself must be taken into account.     

Facial electromyographic responses to emotional information from faces and voices in individuals with pervasive developmental disorder

BACKGROUND: Despite extensive research, it is still debated whether impairments in social skills of individuals with pervasive developmental disorder (PDD) are related to specific deficits in the early processing of emotional information. We aimed to test both automatic processing of facial affect as well as the integration of auditory and visual emotion cues in individuals with PDD. METHODS: In a group of high-functioning adult individuals with PDD and an age- and IQ-matched control group, we measured facial electromyography (EMG) following presentation of visual emotion stimuli (facial expressions) as well as the presentation of audiovisual emotion pairs (faces plus voices). This emotionally driven EMG activity is considered to be a direct correlate of automatic affect processing that is not under intentional control. RESULTS: Our data clearly indicate that among individuals with PDD facial EMG activity is heightened in response to happy and fearful faces, and intact in response to audiovisual affective information. CONCLUSIONS: This study provides evidence for enhanced sensitivity to facial cues at the level of reflex-like emotional responses in individuals with PDD. Furthermore, the findings argue against impairments in crossmodal affect processing at this level of perception. However, given how little comparative work has been done in the area of multisensory perception, there is certainly need for further exploration.     

Iron deficiency in hospitalized infants: study of the incidence of the nutritional factor]

We report an investigation on the iron status of 209 hospitalized 3-month--2-year-old infants over a 6-month period. Hematological parameters and infant feeding practice were determined: a total of 105 infants (50.2%) were found to be iron-depleted, with (24.8%) or without (25.4%) anemia. The mode of lactation appeared to be the main determining factor in iron deficiency, as shown by the fact that during the first months, breast feeding and consumption of an iron-fortified milk formula were 50% less frequent and of shorter duration in infants with iron deficiency than in normal infants. Incorrect diet was also more frequent in iron-deficient infants. It is concluded that iron deficiency in infants could be prevented by better informing mothers in order to encourage breast-feeding and develop the use of an iron-fortified milk formula until the infant reaches the age of one year.     

Cord blood red cell osmotic fragility: a comparison between preterm and full-term newborn infants

BACKGROUND: The osmotic fragility of red blood cells reflects their membrane ability to maintain structural integrity. The osmolality at which the cells lyse is related to their shape, deformability, surface area/volume ratio and intrinsic membrane properties. In cord blood, there may be differences between premature and term infants, and be influenced by maternal medication and other factors. There have been no definitive findings on possible differences between preterm and full-term infant osmotic fragility. AIMS: To determine if cord blood erythrocyte osmotic fragility differs between premature and full-term newborn infants, using two parallel techniques. PATIENTS AND METHODS: Cord blood samples were obtained from preterm singletons (N=11), preterm multiple births (N=10), full-term infants (N=24), as well as adults (N=22), for comparison. An osmotic fragility test was used to determine the NaCl concentration at which 20%, 50% and 80% of hemolysis occurred using individual logistic curves. A glycerol lysis test determined the time needed to lyse 50% of red blood cells. RESULTS: Cord blood red cells of multiple birth premature infants were more hemolysis-resistant than erythrocytes from full-term infants or adults. Another index of osmotic fragility, the difference in NaCl concentration for 80% and 20% red cell hemolysis showed that premature infants had greater differences than full-term infants or adults. Glycerol lysis time revealed that both preterm and full-term infants had an erythrocyte subpopulation that took longer than adult blood to attain 50% hemolysis. Correlation between both tests was very significant (r=-0.603, P<0.0001, N=67). CONCLUSIONS: This study shows that erythrocytes of premature infants, although, in average, less osmotically fragile than those of healthy full-term infants, contain a more hemolysis-susceptible cell subpopulation.     

The effect of cleft lip and palate, and the timing of lip repair on mother-infant interactions and infant development

Background:  Children with cleft lip and palate are at risk for psychological problems. Difficulties in mother–child interactions may be relevant, and could be affected by the timing of lip repair.
Method:  We assessed cognitive development, behaviour problems, and attachment in 94 infants with cleft lip (with and without cleft palate) and 96 non-affected control infants at 18 months; mother–infant interactions were assessed at two, six and 12 months. Index infants received either 'early', neonatal, lip repair, or 'late' repair (3–4 months).
Results:  Index infants did not differ from controls on measures of behaviour problems or attachment, regardless of timing of lip repair; however, infants having late lip repair performed worse on the Bayley Scales of Mental Development; the cognitive development of early repair infants was not impaired. Difficulties in early mother–infant interactions mediated the effects of late lip repair on infant cognitive outcome.
Conclusions:  Early interaction difficulties between mothers and infants having late repair of cleft lip are associated with poor cognitive functioning at 18 months. Interventions to facilitate mother–infant interactions prior to surgical lip repair should be explored.     

Maternal ratings of infant intensity and distractibility: relationship with crying duration in the second month of life

OBJECTIVE: To investigate the relationship between infant temperament characteristics assessed at 4 weeks of age and the duration of infant crying and fussing during the second month of life. DESIGN: Families were enrolled in this prospective study during prenatal classes, and 60 infants completed the study. Temperament was assessed when the infant was 4 weeks of age using the Early Infancy Temperament Questionnaire, and crying and fussing was assessed on 16 days during the second month of life using a parent-completed infant behavior diary. RESULTS: Ratings of the total duration of infant crying and fussing correlated significantly with the sum score on the temperament questionnaire (r = 0.36; P =.005). A longer duration of crying and fussing was associated with infants with high intensity (r = 0.43; P =.001) and low distractibility (r = 0.37; P =.003). CONCLUSIONS: The finding that mothers rating their infants as having high intensity and low distractibility is associated with increased crying duration supports a growing body of literature suggesting that infants with high levels of crying are more reactive to sensory stimuli and harder to soothe than those who cry less. Physicians counseling parents of infants with persistent crying should recognize the infant characteristics associated with increased crying.     

Sudden infant death syndrome in South Australia 1968–97. Part 3: Is bed sharing safe for infants?

OBJECTIVE: To examine the risk of death for bed-sharing infants. METHODOLOGY: All unexpected infant deaths occurring in South Australia between 1970 and 1997, occurring after the infant was put to rest and diagnosed by after death scene investigation and autopsy as sudden death infant syndrome, accidental death, or 'undetermined' were studied. RESULTS: Accidents were the most likely cause of death for 5% of infants who died in designated infant containers (cots, cradles, etc), 24% of those who were sharing a bed or couch, and 72% of those who were placed alone on a bed or couch. CONCLUSIONS: While bed sharing showed an increased risk of dying accidentally, when compared with infants sleeping in designated infant containers, the risk of accidental death in this study was even greater for infants left alone on adult beds or couches.     

Hydropericardium causing sudden infant death in glycogenosis type I: osmotic injury due to percutaneous silastic catheterization

BACKGROUND: The aim of this case report and the review of the literature is to demonstrate dangers when using peripherial silastic catheters in preterm and term newborns or infants. PATIENT, METHODS AND RESULTS: We report on a female infant with glycogenosis type I a (MIM 232200) due to glucose 6-phosphatase deficiency (homozygosity for R170X) and sudden infant death at the age of 9 months due to a rare catheter complication (hydropericardium with tamponade without perforation). CONCLUSION: We believe that this fatal complication was caused by local osmotic dysbalance due to direct contacts between atrial wall and the catheter tip. There is no relation known between patients with inborn errors of metabolism complicated by metabolic derangement and higher incidences of mechanical or non-mechanical catheter complications.     

Do infants of depressed mothers cry more than other infants?

Objectives: This study compared the crying behaviour of infants of depressed and non-depressed mothers at 3 and 6 months of age.
Methodology Twenty-nine depressed and 44 non-depressed mothers, their infants and partners participated in this study. Mothers were asked to complete 24-hour diaries of the amount their infants cried for 1 week.
Results The diurnal variations in crying patterns of infants of depressed and non-depressed mothers were not significantly different. However, infants of depressed mothers were found to cry significantly more in total per day than infants of non-depressed mothers at 3 months of age, but not at 6 months. The results could not be explained by differences in infant temperament.
Conclusion Maternal depression may be a contributory factor to infant crying at 3 months of age.     

Analysis of feeding behavior with direct linear transformation

AIM: The sucking pattern of term infants is composed of a rhythmic alteration of expression and suction movements. The aim is to evaluate if direct linear transformation (DLT) method could be used for the assessment of infant feeding. SUBJECT AND METHODS: A total of 10 gnormalh infants and two infants with neurological disorders were studied using DLT procedures and expression/suction pressure recordings. Feeding pattern of seven gnormalh infants were evaluated simultaneously recording DLT and pressures. The other infants were tested non-simultaneously. We placed markers on the lateral angle of the eye, tip of the jaw, and throat. The faces of infants while sucking were recorded in profile. The jaw and throat movements were calculated using the DLT procedure. Regression analysis was implemented to investigate the relationship between suction and expression pressures and eye-jaw and eye-throat movement. All regression analyses investigated univariate relationships and adjusted for other covariates. RESULTS: Ten gnormalh infants demonstrated higher suction pressure than expression pressure, and their throat movements were larger than jaw movements. Two infants with neurological problems did not generate suction pressure and demonstrated larger movements in their jaw than throat. The simultaneous measurement (n=7) showed a significant correlation, not only between eye-jaw distance and the expression pressure, but also between eye-throat distance and suction pressure. The change in the eye-jaw distance was smaller than the changes in the eye-throat distance in gnormalh infants (p<0.001). CONCLUSIONS: The DLT method can be used to evaluate feeding performance without any special device.     

Child care practices and the sudden infant death syndrome

Southern New Zealand has one of the highest reported rates of the sudden infant death syndrome (SIDS) in the world. Data were collected on 49 infants who died from SIDS in the Dunedin and Invercargill Health Districts of southern New Zealand. Forty-two of the families were interviewed at home following the loss of their infant. In the week prior to death, 17 infants (40%) had an upper respiratory tract infection, although in 11 of these infants their infection had apparently resolved at least 24 h prior to death. Thirty infants (71%) had their faces down into the bedding or their heads covered with bedding. Thirty-four infants (81%) were found dead in the prone position, whereas 49% of New Zealand infants aged 3 months would be expected to sleep prone. Sleep position and the terminal position of the head in relation to SIDS requires further study.     

Maternal BMI and serum leptin concentration of infants in the first year of life

Aim: To evaluate the relationship between serum leptin concentration in infants and infant and maternal BMI. Methods: 75 healthy term infants aged 0-12 mo, 51 exclusively breastfed (BF) for at least 4 mo and 24 formula fed (FF), were included in a cross-sectional study. Weight, length and cranial circumference of infants and their mothers were measured, body mass index (BMI) was calculated using the formula weight (kg)/height (m)² and infant serum leptin concentration was determined. Results: A significant positive correlation between infant serum leptin concentration and maternal BMI was observed in BF infants (r = 0.389, p = 0.005), confirmed in a multiple regression model adjusted for infant age and infant BMI (β = 0.065, p = 0.006), but not in FF infants. As regards the first 4 mo of life, we have already observed a positive correlation between infant serum leptin concentration and maternal BMI in BF infants (β = 0.113, p = 0.005), but not in FF infants.

Conclusion: In BF infants, serum leptin concentration correlates positively with maternal BMI. Higher maternal BMI values might increase leptin levels in breast milk, and maternal adiposity could be involved in infant energy balance.     

Decreased plasma arachidonic acid binding capacity in neonates

Arachidonic acid (AA) metabolites have been implicated in neonatal pathologic states such as respiratory distress syndrome (RDS). Since free (nonprotein bound) AA is the substrate for synthesis of these compounds, a decreased capacity to bind AA in neonatal plasma could contribute to these disorders. AA binding was assayed by equilibrium dialysis in plasma samples from healthy adults and various infant groups. Plasma from these infant groups bound significantly less AA than adult plasma. Premature infants with RDS and premature infants receiving intralipid had the lowest capacity to bind AA. The increased availability of free AA may be important in neonatal pathophysiologic states involving arachidonate metabolites.