Maternal responses to child frustration and requests for help in dyads with fragile X syndrome.

BACKGROUND: Variability in behaviour displayed by children with fragile X syndrome (FXS) may be partially attributable to environmental factors such as maternal responsivity. The purpose of this study was to explore variables associated with maternal behaviour during a task designed to elicit frustration in their children with FXS. METHODS: Forty-six mother-child dyads, in which the child had full-mutation FXS, were observed in their homes during a task designed to elicit frustration in the child. Each child was given a wrong set of keys and asked to open a box to retrieve a desired toy. Mothers were provided with the correct set of keys and instructed to intervene when they perceived their child was getting too frustrated. Child-expressed frustration and requests for help and maternal behaviours (comforting, negative control, and encouraging/directing) were observed and coded. Maternal variables (e.g. depression, stress, education levels), child variables (e.g. autistic behaviours, age, medication use) and child behaviours (frustration, requests for help) were explored as predictors of maternal behaviour. RESULTS: Almost all mothers intervened to help their children and most used encouraging/directing behaviours, whereas very few used comforting or negative control. Child age and child behaviours during the frustrating event were significant predictors of encouraging/directing behaviours in the mothers. Children whose mothers reported higher depressive symptomology used fewer requests for help, and mothers of children with more autistic behaviours used more negative control. CONCLUSIONS: The results of this study suggest that child age and immediate behaviours are more strongly related to maternal responsivity than maternal traits such as depression and stress.

When is an assessment an intervention? Parent perception of infant intentionality and language.

OBJECTIVE: To determine whether the process of having parents rate their infant's intentionality and language using parent-report questionnaires influences parents' tendency to view infants as intentional or linguistic. METHOD: The Infant Intentionality Questionnaire (IIQ) and the MacArthur Communicative Development Inventories (CDI) were administered to three groups of mothers. Forty mothers completed the interviews longitudinally when their infants were 8, 10 and 12 months old. A group of 20 mothers completed the interviews longitudinally when their infants were 10 and 12 months old. A third group of 20 mothers completed the interviews at 12 months only. RESULTS: IIQ scores increased across age but also were higher if parents had more experience with the questionnaire. CDI scores increased with age, but there was no effect of repeated testing. CONCLUSIONS: Previous experience with the IIQ seems to have enhanced the tendency to perceive intentionality. In contrast, repeated testing with the CDI did not alter parent perception of child language. These results suggest that some parent-report instruments (e.g., the IIQ) can alter the test-taker's awareness and thus could serve as an intervention. Parent-report instruments that tap something that is salient, familiar, and easily observable (e.g., the child's language) are less likely to alter the parent's perception.

The development of visual expectations in the first year.

The development of expectations was investigated by using the Visual Expectations Procedure. In Experiment 1, 128 infants aged 6-, 9-, and 12-months-old saw two 40-trial sequences of a videotaped mechanical toy appearing in various locations. The sequences represented an alternation pattern (i.e., ABAB) or a complex pivot pattern (i.e., ABCBABCB). In Experiment 2, 76 infants aged 4-, 8-, and 12-months-old saw either a left-right alternation or a top-bottom alternation. Reaction time improved and the percentage of anticipations increased between 6 and 9 months in Experiment 1 and between 4 and 8 months in Experiment 2 but not thereafter. Anticipations for the pivot sequence and for younger infants on both sequences were often incorrect (i.e., gaze shifts occurred before stimulus onset but were not directed toward the upcoming stimulus). We conclude that young infants have expectations that reflect some degree of general or procedural knowledge, but it is not clear that this behavior implies specific, articulated expectations about upcoming events.

Midazolam: effects on amnesia and anxiety in children.

BACKGROUND: The minimum time interval between administration of oral midazolam and separation of children from their parents that ensures good anterograde amnesia has not been previously determined. This is of particular importance in a busy operating room setting where schedule delays secondary to midazolam administration may not be tolerated. METHODS: Children (n = 113) undergoing general anesthesia and surgery completed preoperative baseline memory testing using a validated series of picture cards and were randomly assigned to one of three midazolam groups or a control group. Exactly, 5, 10, or 20 min after receiving oral midazolam (0.5 mg/kg) or 15 min after receiving placebo, children were administered a second memory test that used pictures. Anxiety of children was assessed during induction of anesthesia with use of a validated anxiety measurement tool. Postoperatively, recall and recognition for picture cards seen during baseline testing and postintervention testing were assessed. RESULTS: Postoperatively, recall and recognition of pictures presented to patients after drug administration (anterograde amnesia) showed significant group differences (P = 0.0001), with recall impaired in the 10- (P = 0.004) and 20-min groups (P = 0.0001). Similarly, recognition memory was impaired in the 5- (P = 0.0008), 10- (P = 0.0001) and 20-min (P = 0.0001) groups. Significant anxiolytic effects of midazolam were observed as early as 15 +/- 4 min after midazolam administration (P = 0.02). CONCLUSIONS: Midazolam administered orally produces significant anterograde amnesia when given as early as 10 min before a surgical procedure.

Measuring variability in early child language: don't shoot the messenger.

Feldman et al. criticize the MacArthur Communicative Development Inventories (CDIs) as having too much variability, too little stability, and insufficient ability to predict early language delay. We present data showing that these characteristics of the CDI are authentic reflections of individual differences in early language development rather than measurement deficiencies. We also respond to their critical assertions concerning sociodemographic influences on the CDI scores.

Measuring infant spatial working memory using a modified delayed-response procedure.

Infant spatial working memory was assessed in 96 nine-month-old human infants using a modification of the delayed-response procedure. A person was the hidden stimulus, gaze was used as the response modality, the response context was a naturalistic "peek-a-boo" game, and a salient cue (i.e. curtains opening to reveal two windows) was used to evoke responses. Infants responded on most trials and performed significantly above chance in delay conditions of 10 and 20 seconds. Reinforcement affected performance, but performance was above chance even in a 0% reinforcement condition. These procedural variations boost estimates of infant spatial working memory over previous estimates and enhance the usefulness of the delayed-response procedure as a marker task for infant spatial working memory.

Representational flexibility and response control in a multistep multilocation search task.

Three experiments were conducted to explore the determinants of 2-year-olds' perseverative errors in a search task. In Experiment 1, children either retrieved an object during a preswitch phase or merely observed a hiding event. Active search produced perseveration on postswitch trials, but mere observation did not. In Experiment 2, similar results were found, even when active search occurred in the absence of observation. Finally, in Experiment 3, children observed a hiding event at 1 location on some pretest trials and simply retrieved an object at a different location on other trials. On test trials, in which an object was hidden at a 3rd location, children tended to search where they had searched previously. Together, the results indicate that active search is required to elicit perseveration, which points to failures of response control rather than representational inflexibility.

Ritual, habit, and perfectionism: the prevalence and development of compulsive-like behavior in normal young children.

Young children engage in a significant amount of ritualistic, repetitive, and compulsive-like activity that appears to be part of their normal behavioral repertoire. Empirically, little is known about the onset, prevalence, and developmental trajectory of these phenomena. A parent-report questionnaire, the Childhood Routines Inventory (CRI), was developed to assess compulsive-like behavior in young children, and was administered to 1,492 parents with children between the ages of 8 and 72 months. The CRI has strong overall internal consistency and a distinct two-factor structure. The frequency of compulsive-like behaviors changes with age: Two-, 3-, and 4-year-olds engaged in more compulsive behavior than children younger than 1 year of age and older than 4 years of age. Results are discussed from a developmental psychopathology framework and for their implications for future research in this area.

A longitudinal twin study of intelligence in the second year.

Data from 408 pairs of identical and same-sex fraternal twins assessed at home and in the laboratory at 14, 20, and 24 months are used to describe cognitive development in the second year and to identify genetic and environmental influences on phenotypic similarity. The primary dependent variables are the Bayley Mental Development Index and separate constructs (based on items from the Bayley and the Sequenced Inventory of Communication Development) to measure nonverbal ability, expressive language, and receptive language. These variables are supplemented with laboratory tests of word comprehension, visual attentiveness, and memory for locations. Various patterns of development emerge for separate constructs, for females versus males on each construct, and for individuals across constructs. These data suggest developmental transitions for many infants during the second year, but the timing of these transitions varies by measure. The dependent variables tend to be intercorrelated and are reasonably stable for individuals, with greater stability late in the second year, suggesting either increasing stability or more effective measurement. Expressive and receptive language scores are correlated and have comparable patterns of change within individuals, but there are also differences (e.g., receptive language accounts for the most variance in MDI at each age and across ages). There are genetic effects on MDI at each age and effects of shared environment at 20 and 24 months. Analyses of separate constructs reveal distinct patterns. Effects on nonverbal abilities are entirely genetic. Effects on language are primarily environmental, but genetic influence emerges for expressive language at 20 and 24 months and for receptive language at 14 months. Visual attentiveness tended to reveal effects comparable to the nonverbal construct, and word comprehension was related to the receptive composite. Scores on the memory for locations task were relatively uninformative. A Cholesky decomposition is used to identify influences that account for the same variance at each age (i.e., promote continuity) and that account for new variance at each assessment (i.e., promote change) and to explore overlap and distinctiveness among measures at each age.

Response modality affects human infant delayed-response performance.

Delayed response performance was assessed in 120 7-, 9-, and 11-month-old infants with correct response defined as either retrieval of a hidden object or gaze toward the location where the object was hidden. Performance improved with age, was above chance for each age group in each condition, and was more often correct with the gaze response. When direction of gaze and reach differed, direction of gaze was more likely to be correct. Infants in the reach condition were more likely to fail to reverse a previously correct response (i.e., to make the A-not-B error). Perseverative responding occurred frequently and was more likely in the reach than the gaze condition. This effect emerged primarily in the context of an incorrect response, which suggests modality-specific sensitivity to the effect of priming rather than reinforcement. Many infants showed strong side biases, and there was a tendency for more reaches to the left but gazes to the right. In a second experiment, 12 5-month-olds gazed toward the correct location more frequently than would be expected by chance but failed to reverse a previously correct response more often than older infants. These findings indicate that response modality has a significant effect on delayed-response performance.

Measuring the vocabulary spurt: a reply to Mervis & Bertrand.

We reply to Mervis & Bertrand's report of three children (aged 1;6-1;8 at the start of the study) who evidenced a 'late' vocabulary spurt. Differences in assessing productive vocabulary, and the questionable inference that size of the lexicon is a reliable indicator of the vocabulary spurt, make it inappropriate to compare these children to previous studies that directly measure change in rate of word learning. Further work using continuous records of lexical development and controls for repeated cognitive assessments is needed to test hypotheses about the spurt and related cognitive and linguistic achievements.

Diary vs. representative checklist assessment of productive vocabulary.

Twenty-four infants were followed longitudinally from 1.2 to 1.10. Parents maintained diaries of the child's spoken words and at two-month intervals completed a representative checklist of words produced. There was good agreement across the two instruments and robust month-to-month correlations for both. However, the overall pattern of results suggests that the diary method is more effective during the early emergence of language and the representative checklist method is more effective late in the second year when vocabulary size becomes relatively large. Accurate longitudinal assessment of vocabulary may require a combination of the diary and checklist approaches.

Developmental and stylistic variation in the composition of early vocabulary.

Results are reported for stylistic and developmental aspects of vocabulary composition for 1,803 children and families who participated in the tri-city norming of a new parental report instrument, the MacArthur Communicative Development Inventories. We replicate previous studies with small samples showing extensive variation in use of common nouns between age 0; 8 and 1;4 (i.e. 'referential style'), and in the proportion of vocabulary made up of closed-class words between 1;4 and 2;6 (i.e. 'analytic' vs. 'holistic' style). However, both style dimensions are confounded with developmental changes in the composition of the lexicon, including three 'waves' of reorganization: (I) an initial increase in percentage of common nouns from 0 to 100 words, followed by a proportional decrease; (2) a slow linear increase in verbs and other predicates, with the greatest gains taking place between 100 and 400 words; (3) no proportional development at all in the use of closed-class vocabulary between 0 and 400 words, followed by a sharp increase from 400 to 680 words. When developmental changes in noun use are controlled, referential-style measures do not show the association with developmental precocity reported in previous studies, although these scores are related to maternal education. By contrast, when developmental changes in grammatical function word use are controlled, high closed-class scores are associated with a slower rate of development. We suggest that younger children may have less perceptual acuity and/or shorter memory spans than older children with the same vocabulary size. As a result, the younger children may ignore unstressed function words until a later point in development while the older children tend to reproduce perceptual details that they do not yet understand. Longitudinal data show that early use of function words (under 400 words) is not related to grammatical levels after the 400-word point, confirming our 'stylistic' interpretation of early closed-class usage. We close with recommendations for the unconfounding of stylistic and developmental variance in research on individual differences in language development, and provide look-up tables that will permit other investigators to pull these aspects apart.

Variability in early communicative development.

Data from parent reports on 1,803 children--derived from a normative study of the MacArthur Communicative Development Inventories (CDIs)--are used to describe the typical course and the extent of variability in major features of communicative development between 8 and 30 months of age. The two instruments, one designed for 8-16-month-old infants, the other for 16-30-month-old toddlers, are both reliable and valid, confirming the value of parent reports that are based on contemporary behavior and a recognition format. Growth trends are described for children scoring at the 10th-, 25th-, 50th-, 75th-, and 90th-percentile levels on receptive and expressive vocabulary, actions and gestures, and a number of aspects of morphology and syntax. Extensive variability exists in the rate of lexical, gestural, and grammatical development. The wide variability across children in the time of onset and course of acquisition of these skills challenges the meaningfulness of the concept of the modal child. At the same time, moderate to high intercorrelations are found among the different skills both concurrently and predictively (across a 6-month period). Sex differences consistently favor females; however, these are very small, typically accounting for 1%-2% of the variance. The effects of SES and birth order are even smaller within this age range. The inventories offer objective criteria for defining typicality and exceptionality, and their cost effectiveness facilitates the aggregation of large data sets needed to address many issues of contemporary theoretical interest. The present data also offer unusually detailed information on the course of development of individual lexical, gestural, and grammatical items and features. Adaptations of the CDIs to other languages have opened new possibilities for cross-linguistic explorations of sequence, rate, and variability of communicative development.

Genetic change and continuity from fourteen to twenty months: the MacArthur Longitudinal Twin Study.

Genetic change as well as continuity was investigated within the domains of temperament, emotion, and cognition/language for 200 pairs of twins assessed at 14 and 20 months of age in the laboratory and home. The second year of life is marked by change rather than continuity: correlations from 14 to 20 months averaged about .30 for observational measures of temperament and emotion, about .40 for language measures, and about .50 for mental development. 2 types of genetic change were examined: changes in the magnitude of genetic influence (heritability) and genetic contributions to change from 14 to 20 months. In general, heritability estimates were similar at 14 and 20 months. Evidence for genetic influence on change from 14 to 20 months emerged for several measures, implying that heritability cannot be equated with stability. Analyses of continuity indicated that genetic factors are largely responsible for continuity from 14 to 20 months.

Temperament, emotion, and cognition at fourteen months: the MacArthur Longitudinal Twin Study.

200 pairs of twins were assessed at 14 months of age in the laboratory and home. Measures were obtained of temperament, emotion, and cognition/language. Comparisons between identical and fraternal twin correlations suggest that individual differences are due in part to heritable influences. For temperament, genetic influence was significant for behavioral observations of inhibition to the unfamiliar, tester ratings of activity, and parental ratings of temperament. For emotion, significant genetic influence was found for empathy and parental ratings of negative emotion. The estimate of heritability for parental report of expression of negative emotions was relatively high, whereas that for expression of positive emotions was low, a finding consistent with previous research. For cognition and language, genetic influence was significant for behavioral indices of spatial memory, categorization, and word comprehension. Shared rearing environment appears influential for parental reports of language and for positive emotions, but not for other measures of emotion or for temperament.

Stable behavioral inhibition and its association with anxiety disorder.

"Behavioral inhibition to the unfamiliar" is a temperamental construct reflecting the tendency to be shy, timid, and constrained in novel situations. Previous work has suggested that it may be associated with anxiety disorders in children. Psychopathology was assessed in children from a nonclinical sample originally identified as behaviorally inhibited or uninhibited at 21 months and followed through 7 1/2 years. Children who remained inhibited at 4, 5 1/2 and 7 1/2 years (Stable Inhibited) had higher rates of anxiety disorders than children who were not consistently inhibited. Their parents had higher rates of multiple childhood anxiety disorders and of continuing anxiety disorder. These results suggest that the association between behavioral inhibition and anxiety disorder is accounted for by children who have stable behavioral inhibition.

Further evidence of an association between behavioral inhibition and anxiety disorders: results from a family study of children from a non-clinical sample.

Behavioral inhibition to the unfamiliar, identifiable in early childhood and reflecting the tendency to exhibit withdrawal and excessive autonomic arousal to challenge or novelty, has been found to be prevalent in young offspring of parents with panic disorder and agoraphobia and associated with risk for anxiety disorders in these children. Using family study methodology, we now examine psychopathology in first degree relatives of children from a non-clinical longitudinal cohort identified at 21 months of age as inhibited (N = 22) or uninhibited (N = 19) and followed through the age of seven years for a study of preservation of temperamental characteristics in normal children. These assessments were compared with evaluations of the first degree relatives of 20 normal comparison children. Psychiatric assessments of parents (N = 110) and siblings (N = 72) were based on structured interviews conducted blindly to the temperamental classification of the index child. Parents of inhibited children, compared with parents of uninhibited and normal controls, had significantly higher risks for multiple (greater than or equal to 2) anxiety disorders, continuing anxiety disorders (both a childhood and adulthood anxiety disorder in the same parent), social phobia, and childhood avoidant and overanxious disorders. These findings provide additional support for the hypothesis linking behavioral inhibition with risk for anxiety disorder.

Early lexical acquisition: rate, content, and the vocabulary spurt.

The transition from slow to rapid word-learning was examined in a longitudinal study of 18 children. Beginning at age 1.2, mothers kept a diary of children's words. Diary entries were discussed during phone calls to the home every 2 1/2 weeks. A chronological record of nouns and other word classes was coded from the diary records. Thirteen children evidenced a prolonged period of up to three months during which rate of acquisition markedly increased. Almost three-quarters of the words learned during this period were nouns. Five children evidenced more gradual word-learning, and acquired a balance of nouns and other word classes. These results suggest that the terms 'vocabulary spurt' and 'naming explosion' best describe children who focus their early linguistic efforts on a single strategy: learning names for things. Other children may attempt to encode a broad range of experience with a more varied lexicon, a strategy that results in more gradual lexical growth.

Psychiatric correlates of behavioral inhibition in young children of parents with and without psychiatric disorders.

Behavioral inhibition is a laboratory-based temperamental category by the tendency to constrict behavior in unfamiliar situations and assumed to reflect low thresholds of limbic arousal. We previously found behavioral inhibition prevalent in the offspring of parents with panic disorder and agoraphobia. In this report, we examined the psychiatric correlates of behavioral inhibition by evaluating the sample of offspring of parents with panic disorder and agoraphobia, previously dichotomized as inhibited and not inhibited, and an existing epidemiologically derived sample of children, followed by Kagan and colleagues and originally identified at 21 months of age as inhibited or uninhibited. A third group of healthy children was added for comparison. Our findings indicate that inhibited children had increased risk for multiple anxiety, overanxious, and phobic disorders. It is suggested that behavioral inhibition may be associated with risk for anxiety disorders in children.