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PubMed2001

Predictors and correlates of adaptive functioning in children with developmental disorders.

Autism is a developmental disorder marked by impairments in socialization, communication, and perseverative behavior and is associated with cognitive impairment and deficits in adaptive functioning. Research has consistently demonstrated that children with autism have deficits in adaptive functioning more severe than their cognitive deficits. This study investigates the correlates and predictors of adaptive functioning as measured by the Vineland Adaptive Behavior Scales in high- and low-functioning children with autism and their age and nonverbal IQ matched controls. Thirty-five 9-year-old children with high-functioning autism (HAD) were compared with 31 age-matched children with developmental language disorder (DLD), and 40 9-year-old children with low-functioning autism (LAD) were compared with 17 age-matched children with low IQ on adaptive functioning, IQ, autistic symptomology, and tests of language and verbal memory. Results indicate that both groups with autism were significantly impaired compared to their matched controls on Socialization and Daily Living, but not Communication and that these impairments were more pronounced in the HAD group than in the LAD group. Adaptive behavior was strongly correlated with autistic symptomology only in the HAD group. Regression analyses indicated that IQ was strongly predictive of adaptive behavior in both low-functioning groups, but tests of language and verbal memory predicted adaptive behavior in the higher functioning groups. Results suggest that IQ may act as a limiting factor for lower functioning children but higher functioning children are impaired by specific deficits, including autistic symptomology and impaired language and verbal memory.

Adaptation, Psychological↗
PubMed2005

Computational adaptation model and its predictions for color induction of first and second orders.

The appearance of a patch of color or its contrast depends not only on the stimulus itself but also on the surrounding stimuli (induction effects-simultaneous contrast). A comprehensive computational physiological model is presented to describe chromatic adaptation of the first (retinal) and second (cortical) orders, and to predict the different chromatic induction effects. We propose that the chromatic induction of the first order that yields perceived complementary colors can be predicted by retinal adaptation mechanisms, contrary to previous suggestions. The second order of the proposed adaptation mechanism succeeds to predict the automatic perceived inhibition or facilitation of the central contrast of a texture stimulus, depending on the surrounding contrast. Furthermore, contrary to other models, this model is able to also predict the effect of variegated surrounding on the central perceived color.

Adaptation, Physiological↗
PubMed2006

The transition to school: adaptation in young children with and without intellectual disability.

BACKGROUND: Previous research has highlighted the importance of the transition to school for young children and their families. A child's successful adaptation to school is likely influenced by a number of factors, including academic, social, emotional, behavioural and cognitive competencies. Children with intellectual disability (ID) may be at heightened risk for early school difficulties, in part due to their deficits in cognitive and adaptive behaviours. METHODS: Factors associated with the adaptive transition to school in young children with (n = 24) and without (n = 43) ID were examined. Adaptive transitions were defined as having few teacher-reported problem behaviours and positive student-teacher relationships. Child self-regulatory skills and both parent- and teacher-reported social skills were evaluated to determine if they predicted positive adaptation in school for 5- to 6-year-old children. Data were gathered from child assessments, parent reports on standardized measures, direct observations of delay of gratification tasks and teacher reports on standardized measures. RESULTS: Children with ID had significantly more teacher-reported problem behaviour, poorer overall student-teacher relationships, fewer parent- and teacher-reported social skills and fewer self-regulation skills than typically developing children. Self-regulation at child age 36 months (latency to touch a desired toy) was significantly related to adaptation to school, as were parent and teacher reports of social skills. Social skills significantly predicted adaptation to school, even after accounting for the effects of child IQ and adaptive behaviour. CONCLUSIONS: Children with ID had less positive early school experiences, as indicated by multiple indices of adaptation to school. Fostering early social skills may be an important target for increasing the positive adaptation to school for young children, especially those with ID.

Adaptation, Psychological↗
PubMed1987

Mothers of children with autism or communication disorders: successful adaptation and the double ABCX model.

This study demonstrates the effectiveness of a modified Double ABCX or FAAR model in predicting successful adaptation--good marital adjustment, few maternal depressive symptoms, and an in-home rating of family functioning--in 45 families of autistic and communication-impaired children. The model consisted of severity of the handicap and other family stresses, family resources of cohesion and social support, family definition of the handicap, and adequacy of coping patterns. Canonical correlation and subsequent multiple regression procedures demonstrated that family adaptation was positively predicted by adequacy of social support and active coping patterns. Poorer adaptation was predicted by other family stresses, unwarranted maternal self-blame for the handicap, and maternal definition of the handicap as a family catastrophe. Findings for cohesion were mixed. Resources and beliefs were more predictive of adaptation than severity of the child's handicap.

Adaptation, Psychological↗
PubMed1984

Spatial-frequency adaptation and grating discrimination: predictions of a line-element model.

Recent data have shown that spatial-frequency adaptation has little effect on spatial-frequency discrimination at the adapting frequency, but there is a substantial elevation of discrimination thresholds at frequencies about one octave higher than the adapting frequency. It has also been shown that adaptation produces elevations in grating-orientation discrimination at orientations displaced by +/- 12.0-15.0 deg from the adapting orientation. In this paper, we show that these results agree quantitatively with the predictions (some of which were made without knowledge of the experimental results) of a line-element model for spatial-frequency discrimination. Spatial-frequency bandwidths of the visual mechanisms were previously obtained from masking data. For the orientation-discrimination predictions, the line-element model was generalized to incorporate orientation bandwidths for the spatial mechanisms, again estimated from masking data.

Adaptation, Physiological↗
PubMed2000

Unstable Morse code recognition with adaptive variable-ratio threshold prediction for physically disabled persons.

With one or two switches, Morse code could provide an effective alternative communication channel for individuals with physical limitations. However, most of the physically disabled persons have difficulties in maintaining a stable typing of Morse code, and hence the automated recognition of unstable Morse code is becoming more on demand. In this study, an adaptive variable-ratio threshold prediction (AVRTP) algorithm is proposed to analyze the Morse code time series with variable unit time period and ratio. Two least-mean-square (LMS) predictors are applied to track the dot interval and the dot-dash difference concurrently, and then a predicted threshold based on a variable-ratio decision rule is used to distinguish between dots and dashes. The same method is also applied to identify character-spaces. By the adaptive prediction of variable-ratio threshold, AVRTP has successfully overcome the difficulty of analyzing severely unstable Morse code time series and outperformed the previously proposed adaptive unstable-speed prediction (AUSP) algorithm and LMS and matching (I,MS&M) algorithm. This study concludes with a computer simulation and a preliminary clinical evaluation that demonstrate AVRTP as an efficient and reliable method for unstable Morse code recognition.

Adolescent↗
PubMed2001

Genetic adaptive neural network to predict biochemical failure after radical prostatectomy: a multi-institutional study.

BACKGROUND AND PURPOSE: Despite many new procedures, radical prostatectomy remains one of the commonest methods of treating clinically localized prostate cancer. Both from the physician's and the patient's point of view, it is important to have objective estimation of the likelihood of recurrence, which forms the foundation for treatment selection for an individual patient. Currently, it is difficult to predict the probability of biochemical recurrence (rising serum prostate specific antigen [PSA] concentration) in an individual patient, and approximately 30% of the patients do experience recurrence. Tools predicting the recurrence will be of immense practical utility in the treatment selection and planning follow up. We have utilized preoperative parameters through a computer based genetic adaptive neural network model to predict recurrence in such patients, which can help primary care physicians and urologists in making management recommendations. PATIENTS AND METHODS: Fourteen hundred patients who underwent radical prostatectomy at participating institutions form the subjects of this study. Demographic data such as age, race, preoperative PSA, systemic biopsy based staging and Gleason scores were used to construct a neural network model. This model simulated the functioning of a trained human mind and learned from the database. Once trained, it was used to predict the outcomes in new patients. RESULTS: The patients in this comprehensive database were representative of the average prostate cancer patients as seen in USA. Their mean age was 68.4 years, the mean PSA concentration before surgery was 11.6 ng/mL, and 67% patients had a Gleason sum of 5 to 7. The mean length of follow-up was 41.5 months. Eighty percent of the cancers were clinical stage T2 and 5% T3. In our series, 64% of patients had pathologically organ-confined cancer, 33% positive margins, and 14% had seminal vesicle invasion. Lymph node positive patients were not included in this series. Progression as judged by serum PSA was noted in 30.6%. With entry of a few routinely used parameters, the model could correctly predict recurrence in 76% of the patients in the validation set. The area under the curve was 0.831. The sensitivity was 85%, the specificity 74%, the positive predictive value 77%, and the negative predictive value of 83%. CONCLUSION: It was possible to predict PSA recurrence with a high accuracy (76%). Physicians desiring objective treatment counseling can use this model, and significant cost savings are anticipated because of appropriate treatment selection and patient-specific follow-up protocols. This technology can be extended to other treatments such as watchful waiting, external-beam radiation, and brachytherapy.

Aged↗
PubMed2006

Predictors of personality change due to traumatic brain injury in children and adolescents six to twenty-four months after injury.

Phenomenology and predictive factors of personality change due to traumatic brain injury (TBI) 6 to 24 months after injury was investigated in children, ages 5 to 14 years, enrolled from consecutive admissions and followed prospectively for 2 years. Injury and preinjury psychosocial variables were assessed. Personality change occurred in 13% of participants between 6 and 12 months after injury and 12% in the second year after injury. Severity of injury consistently predicted personality change, and preinjury adaptive function predicted personality change only in the second year postinjury. Lesions of the superior frontal gyrus were associated with personality change between 6 and 12 months following injury, after controlling for severity of injury and the presence of other brain lesions. Only lesions in the frontal lobe white matter were significantly related to personality change in the second year after injury. After childhood TBI, neural correlates of personality change evolve between 6 and 12 months and 12 to 24 months after injury. The data implicate the dorsal prefrontal cortex and frontal lobe white matter in the emergence of personality change involving the effortful or conscious regulation of affective states.

Adolescent↗
PubMed2003

Predicting the consequences of social stressors on pig food intake and performance.

The influence of social stressors on pig performance, although undeniable, is frequently underestimated, and in pig growth modeling is generally ignored. The aims here were to quantify the effects of the main social stressors (i.e., group size, space allowance, feeder space allowance, and mixing) on the performance of growing pigs and to incorporate these relationships into a general growth simulation model. Effects of the individual stressors were described by conceptual equations derived on biological grounds. Parameter values were estimated from experimental data, while taking steps to avoid the problems of using a strictly empirical approach. It was assumed that social stress decreases the capacity of the animal to attain its potential. This is equivalent to lowering the maximum rate of daily gain (ADGp, kg/d). Because it is generally assumed that animals eat to attain their potential, a decrease in ADGp necessarily leads to a decrease in intake. Genetic variation among genotypes in their ability to cope with social stressors was accounted for by introducing an extra genetic parameter (EX) into the model. The value of EX adjusts both the intensity of stressor at which the animal becomes effectively stressed and the extent to which stress decreases performance and increases energy expenditure at a given stressor intensity. Rather than using an empirical adjustment to predict values for the model output variables, such as intake and gain, the chosen functional forms were integrated into a general growth model as mechanistic equations. This allowed the effects of interactions that exist between social stressors and the other variables, such as the genotype, feed composition, and environment on pig intake and growth, to be explored and, at least in principle, predicted. The adapted model is able to predict the performance of pigs differing in both the potential and ability to cope with environmental stressors when raised under given dietary, physical, and social environmental conditions. The social stressor equations developed here can be incorporated into other pig growth simulation models.

Animal Feed↗
PubMed2007

A comparison of regression trees, logistic regression, generalized additive models, and multivariate adaptive regression splines for predicting AMI mortality.

Clinicians and health service researchers are frequently interested in predicting patient-specific probabilities of adverse events (e.g. death, disease recurrence, post-operative complications, hospital readmission). There is an increasing interest in the use of classification and regression trees (CART) for predicting outcomes in clinical studies. We compared the predictive accuracy of logistic regression with that of regression trees for predicting mortality after hospitalization with an acute myocardial infarction (AMI). We also examined the predictive ability of two other types of data-driven models: generalized additive models (GAMs) and multivariate adaptive regression splines (MARS). We used data on 9484 patients admitted to hospital with an AMI in Ontario. We used repeated split-sample validation: the data were randomly divided into derivation and validation samples. Predictive models were estimated using the derivation sample and the predictive accuracy of the resultant model was assessed using the area under the receiver operating characteristic (ROC) curve in the validation sample. This process was repeated 1000 times-the initial data set was randomly divided into derivation and validation samples 1000 times, and the predictive accuracy of each method was assessed each time. The mean ROC curve area for the regression tree models in the 1000 derivation samples was 0.762, while the mean ROC curve area of a simple logistic regression model was 0.845. The mean ROC curve areas for the other methods ranged from a low of 0.831 to a high of 0.851. Our study shows that regression trees do not perform as well as logistic regression for predicting mortality following AMI. However, the logistic regression model had performance comparable to that of more flexible, data-driven models such as GAMs and MARS.

Data Interpretation, Statistical↗
PubMed2005

On using an adaptive neural network to predict lung tumor motion during respiration for radiotherapy applications.

In this study we address the problem of predicting the position of a moving lung tumor during respiration on the basis of external breathing signals--a technique used for beam gating, tracking, and other dynamic motion management techniques in radiation therapy. We demonstrate the use of neural network filters to correlate tumor position with external surrogate markers while simultaneously predicting the motion ahead in time, for situations in which neither the breathing pattern nor the correlation between moving anatomical elements is constant in time. One pancreatic cancer patient and two lung cancer patients with mid/upper lobe tumors were fluoroscopically imaged to observe tumor motion synchronously with the movement of external chest markers during free breathing. The external marker position was provided as input to a feed-forward neural network that correlated the marker and tumor movement to predict the tumor position up to 800 ms in advance. The predicted tumor position was compared to its observed position to establish the accuracy with which the filter could dynamically track tumor motion under nonstationary conditions. These results were compared to simplified linear versions of the filter. The two lung cancer patients exhibited complex respiratory behavior in which the correlation between surrogate marker and tumor position changed with each cycle of breathing. By automatically and continuously adjusting its parameters to the observations, the neural network achieved better tracking accuracy than the fixed and adaptive linear filters. Variability and instability in human respiration complicate the task of predicting tumor position from surrogate breathing signals. Our results show that adaptive signal-processing filters can provide more accurate tumor position estimates than simpler stationary filters when presented with nonstationary breathing motion.

Biophysical Phenomena↗
PubMed1999

Symptoms of depression are important to psychological adaptation and metabolic control in children with diabetes mellitus.

AIMS: Sixty-two children (37 girls, 25 boys) between 9 and 18 years of age were enrolled to investigate: (1) the relationship between adaptation to diabetes mellitus (DM) and psychological functioning; (2) if adaptation or psychological functioning was related to metabolic control; and (3) if the patients' ability to cope with diabetes as assessed by physicians, was correlated to adaptation or psychological functioning. METHODS: Psychological functioning was measured by three general psychological instruments for depressive symptoms, self-esteem and fear. Diabetes adaptation was evaluated by questionnaires and coping with diabetes by an assessment of the physicians. Metabolic control was expressed by the individual HbA1c measured during the last year. RESULTS: Adaptation to diabetes correlated to psychological functioning (depression, P<0.001; self-esteem, P<0.01; and fear, P<0.01). Multiple regression analyses showed that metabolic control was predicted by adaptation (P=0.0013) with monitoring of diabetes as the only significant aspect of the adaptation (P < or = 0.0001). In turn, adaptation was predicted by symptoms of depression and metabolic control (P<0.0001). In support of this observation, a depressed (n = 9) and a non depressed (n= 53) group showed significant differences in metabolic control (P < or = 0.01), adaptation (P < or = 0.001) and self-esteem (P < or = 0.001). The only significant variable for the physicians assessment was metabolic control, which explained 35 % of the variance (P < 0.001). CONCLUSIONS: The major conclusion is that symptoms of depression affect both adaptation and metabolic control. It should be of concern to identify patients with depressive symptoms, offer treatment for their emotional difficulties and increase the support for taking care of their diabetes.

Adaptation, Psychological↗
PubMed1998

Relations between family predictors and child outcomes: are they weaker for children in child care? NICHD Early Child Care Research Network.

Studies suggesting that family factors predict developmental outcomes more strongly for children reared principally by their parents than those with extensive early child-care experience stimulated the examination of the differential prediction of child outcomes using a subsample of families participating in the National Institute of Child Health and Human Development (NICHD) Study of Early Child Care. A variety of factors were used to predict development of children who averaged 30 hr of nonparental care per week for each month of their lives and for those who never experienced more than 10 hr of care per week by someone other than their mothers. Multivariate analyses provided no evidence that family factors predicted outcomes differentially for these 2 groups, though exploratory analyses revealed several instances of differential prediction.

Adaptation, Psychological↗
PubMed1986

Adaptation level as an explanation of the peak shift in generalization with movement stimuli.

Two experiments examine the value of adaptation level theory as an explanation of the peak shift phenomenon in stimulus generalization using linear arm movements. The first experiment manipulates the differences in adaptation levels during training by varying the frequency of experience of the training stimulus. Significant shifts in the peaks of generalization gradients were subsequently identified. The peak shifts were in the direction predicted by adaptation level theory. The second experiment manipulates testing adaptation levels by biasing the generalization test movements. Three groups of subjects performed differentially weighted test sequences in which the relative number of short, medium, or long movements was manipulated. Significant peak shifts of generalization gradients were observed in the direction predicted by adaptation level theory.

Journal Article↗
PubMed1977

Psychological changes accompanying pregnancy and motherhood.

This study was an attempt to investigate some of the psychological changes that occur during first pregnancy and the early postpartum months. The major theoretical assumption was that pregnancy and early motherhood may be viewed as a series of developmental tasks, and that the way in which these are coped with will be predictive of adaptation to the maternal role. The aims of the study were (a) to identify the affective changes that occur in women during first pregnancy and to assess the extent to which pregnancy and motherhood are experienced as a period of psychological crisis; (b) to trace the development of maternal feeling; and (c) to assess the extent to which characteristics measured early in pregnancy are predictive of attitudes and adjustment to later stages of pregnancy and the degree to which these factors are themselves predictive of adaptation to parenthood. The sample consisted of 19 white, middle class primigravidas, with an age range of 22-33 years. Only women who had no previous gynecological or psychiatric difficulties and who were currently living with their husbands were accepted as Ss. Each woman was interviewed at each trimester of pregnancy, on the third postpartum day, and at 2 months postpartum. A follow up questionnaire was mailed at 7 months postpartum, The data obtained were derived from ratings of extensive interview schedules and a number of personality measures. Results indicated that although emotional upheaval and rapid change were characteristic of pregnancy, for some women a growing sense of adulthood, of fulfillment, and integration of a new maturational stage clearly co-existed with the emotional disequilibrium. Analysis of the interrelationship among characteristics shown in early pregnancy, adjustment to the pregnancy overall, and adaptation to parenthood indicated that the degree of personality integration achieved by early pregnancy was predictive of the extent to which psychological growth was experienced throughout pregnancy and early parenthood.

Adaptation, Psychological↗
PubMed1995

The long-term consequences of infant day-care and mother-infant attachment.

The aim of this study was to explore the within-group effects of mother-infant attachment and day-care on children's social and emotional adaptation at 42 months and in the early school years. For this high-risk sample, the effects of day-care depended on the quality of mother-infant attachment. Day-care appeared to have a negative effect for secure children but had a positive influence for insecure children. For the secure group, children in day-care were more negative and avoidant at 42 months, and they were more externalizing and aggressive in kindergarten compared to the home-reared group. In contrast, day-care children who were insecurely attached were less withdrawn and more agentic. Overall, day-care children were rated higher on externalizing behavior in kindergarten than home-reared children, but no differences were found in the later school years. The sequelae of attachment indicated that security of attachment during infancy differentially predicted later adaptation for day-care and home-reared children. Attachment was related to later adaptation for home-reared children but did not predict later adaptation for day-care children.

Aggression↗
PubMed1981

Interlimb transfer after adaptation to visual displacement: patterns predicted from the functional closeness of limb neural control centres.

Two experiments were designed to determine whether interlimb transfer of prism adaptation follows a pattern predicted by the functional closeness of limb control centres. Subjects were adapted to a lateral displacing prism with their right arm in conditions known to facilitate interlimb transfer. Negative aftereffect measures of target-pointing shift were taken for all limbs. If transfer to the unadapted limbs is primarily the result of some sort of visual change, scores for those limbs should not differ. However, if the functional cerebral closeness of limb control centres is a factor, the greatest shift should be evidenced in the homologous contralateral limb (left arm), followed by the ipsilateral limb (right leg), with the least shift to the diagonally opposite limb (left leg). No differences in shift among the three unadapted limbs was found in the two experiments.

Adaptation, Ocular↗