Diagnostic accuracy of ASQ for screening of neurodevelopmental delays in low resource countries

OBJECTIVE

The Bayley Scales of Infant Development (BSID) is the most used diagnostic tool to identify neurodevelopmental disorders in children under age 3 but is challenging to use in low-resource countries. The Ages and Stages Questionnaire (ASQ) is an easy-to-use, low-cost clinical tool completed by parents/caregivers that screens children for developmental delay. The objective was to determine the performance of ASQ as a screening tool for neurodevelopmental impairment when compared with BSID second edition (BSID-II) for the diagnosis of moderate-to-severe neurodevelopmental impairment among infants at 12 and 18 months of age in low-resource countries.

METHODS

Study participants were recruited as part of the First Bites Complementary Feeding trial from the Democratic Republic of Congo, Zambia, Guatemala and Pakistan between October 2008 and January 2011. Study participants underwent neurodevelopmental assessment by trained personnel using the ASQ and BSID-II at 12 and 18 months of age.

RESULTS

Data on both ASQ and BSID-II assessments of 1034 infants were analysed. Four of five ASQ domains had specificities greater than 90% for severe neurodevelopmental delay at 18 months of age. Sensitivities ranged from 23% to 62%. The correlations between ASQ communications subscale and BSID-II Mental Development Index (MDI) (r=0.38) and between ASQ gross motor subscale and BSID-II Psychomotor Development Index (PDI) (r=0.33) were the strongest correlations found.

CONCLUSION

At 18 months, ASQ had high specificity but moderate-to-low sensitivity for BSID-II MDI and/or PDI <70. ASQ, when administered by trained healthcare workers, may be a useful screening tool to detect severe disability in infants from rural low-income to middle-income settings.

TRIAL REGISTRATION NUMBER

NCT01084109.

The intersection of gross motor abilities and participation in children with autism spectrum disorder

Many children with autism spectrum disorder (ASD) demonstrate movement difficulties in addition to problems with social communication and interactions, and repetitive or restrictive behaviors. The goal of early intervention for children with disabilities is to promote participation in routines and activities, but little is known about the role gross motor abilities contribute to participation for young children with ASD. The purpose of this study was to examine relationships between gross motor abilities and participation in preschool-aged children with ASD. Twenty-two children with ASD participated in the study. Gross motor skills were measured using the Peabody Developmental Motor Scales, Second Edition. Participation was measured using the Preschool Activity Card Sort. Children who had greater gross motor skills also demonstrated greater participation in self-care, high demand leisure, and social interaction activities. Results also identified activities that may be difficult for preschoolers with ASD. Findings suggest that early childhood intervention providers consider the impact of gross motor deficits within the context of participation in daily routines and activities.

Maternal methylmercury exposure through rice ingestion and child neurodevelopment in the first three years: a prospective cohort study in rural China

BACKGROUND

Rice is an important dietary source for methylmercury; however, rice does not contain the same beneficial nutrients as fish. Our main objective was to assess associations of prenatal methylmercury exposure through rice ingestion with child neurodevelopment in rural China.

METHODS

Eligible peripartum women were enrolled (n = 391), provided peripartum hair samples, and children's neurodevelopment was assessed at 12 months (n = 264, 68%) and 36 months (n = 190, 48%) using the Bayley Scales of Infant Development, 2nd Edition, including the Mental Developmental Index (MDI) and the Psychomotor Developmental Index (PDI). Associations between prenatal methylmercury exposure during the third trimester [log2 maternal hair total mercury (THg)] and child's neurodevelopment were assessed using linear mixed models for repeated measures.

RESULTS

In adjusted models, a doubling in maternal hair THg corresponded to a 1.3-point decrement in the MDI score [95% confidence interval (CI): - 2.6, - 0.14], and a 1.2-point decrement in the PDI score (95% CI: - 2.6, 0.14). Overall, adverse associations between maternal hair THg and MDI scores attenuated over time. However, associations were robust and stable over time among children whose primary caregiver was their parent(s). During the study follow-up, an increasing proportion of children were raised by grandparents (12 months: 9% versus 36 months: 27%), a trend associated with rural-to-urban parental migration for work.

CONCLUSIONS

For young children living in rural China, a biomarker of prenatal methylmercury exposure was associated with decrements in cognitive function assessed between 12 and 36 months of age. Changes in the family structure over the study follow-up time interval potentially impacted children's sensitivity to prenatal methylmercury exposure.

Neurodevelopment correlates with gut microbiota in a cross-sectional analysis of children at 3 years of age in rural China

We investigated cross-sectional associations between children's neurodevelopment and their gut microbiota composition. Study children (36 months of age) lived in rural China (n = 46). Neurodevelopment was assessed using the Bayley Scales of Infant Development, 2nd Edition, yielding the Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI). Children's gut microbiota was assessed using 16S rRNA gene profiling. Microbial diversity was characterized using alpha diversity patterns. Additionally, 3 coabundance factors were determined for the 25 most abundant taxa. Multivariable linear regression models were constructed to examine the relationships between Bayley scores (MDI and PDI) and children's gut microbiota. In adjusted models, MDI and PDI scores were not associated with alpha diversity indices. However, in adjusted models, MDI and PDI scores were positively associated with the first coabundance factor, which captured positive loadings for the genera Faecalibacterium, Sutterella, and Clostridium cluster XIVa. For an interquartile range increase in the first coabundance factor, MDI scores increased by 3.9 points [95% confidence interval (CI): 0, 7.7], while PDI scores increased by 8.6 points (95% CI 3.1, 14). Our results highlight the potential for gut microbial compositional characteristics to be important correlates of children's Bayley Scales performance at 36 months of age.

General anesthesia for cesarean delivery and childhood neurodevelopmental and perinatal outcomes: a secondary analysis of a randomized controlled trial

BACKGROUND

In 2016, the U.S. Food and Drug Administration expressed concern that neurodevelopment may be negatively affected by anesthesia or sedation exposure in pregnancy or before three years of age. We examined the association between general anesthesia at the time of cesarean delivery and early childhood neurodevelopment.

METHODS

A secondary analysis of a multicenter randomized controlled trial assessing magnesium for prevention of cerebral palsy in infants at risk for preterm delivery. Exposure was general compared to neuraxial anesthesia. The primary outcome was motor or mental delay at two years of age, assessed by Bayley Scales of Infant Development II (BSIDII). Secondary outcomes included BSIDII subdomains and perinatal outcomes. Multivariable logistic regression models were performed to control for confounders.

RESULTS

Of 557 women undergoing cesarean delivery, 119 (21%) received general anesthesia. There were no differences in the primary composite outcome of developmental delay (aOR 0.93, 95% CI 0.61 to 1.43) or the BSIDII subdomains of mild, moderate, or severe mental delay, or mild or moderate motor delay. Severe motor delay was more common among infants exposed to general anesthesia (aOR 1.98, 95% CI 1.06 to 3.69). Infants exposed to general anesthesia had longer neonatal intensive care stays (51 vs 37 days, P=0.010).

CONCLUSIONS

General anesthesia for cesarean delivery was not associated with overall neurodevelopmental delay at two years of age, except for greater odds of severe motor delay. Future studies should evaluate this finding, as well as the impact on neurodevelopment of longer or multiple anesthetic exposures across all gestational ages.

Associations between feeding practices and growth and neurodevelopmental outcomes at 36 months among children living in low- and low-middle income countries who participated in the BRAIN-HIT trial

BACKGROUND

Feeding practices over the first several years of a child's life can critically influence development. The purpose of this study was to examine associations between feeding practices and growth and neurodevelopmental outcomes at 36 months of age among children from low- and low-middle-income countries (LMIC).

METHODS

We conducted a secondary analysis using data collected from children in India, Pakistan, and Zambia who were enrolled in a randomized controlled trial of a home-based early development intervention program called Brain Research to Ameliorate Impaired Neurodevelopment Home-based Intervention Trial. Qualitative dietary data collected at 36 months was used to assess the modified Minimum Acceptable Diet (mMAD), a measure based on a core indicator developed by the World Health Organization to measure whether young children receive the minimum number of meals recommended and adequate diversity of major food groups in their diet. Regression models were used to assess cross-sectional associations between diet and growth indices, including Z-scores for height-for-age (HAZ), weight-for-age (WAZ), weight-for-height (WHZ), head circumference (HCZ), and Bayley Scales of Infant Development II mental and psychomotor developmental measures at 36 months of age.

RESULTS

Of 371 children, 174 (47%) consumed the mMAD, with significantly higher mean adjusted WHZ than those who did not meet mMAD (0.20 vs - 0.08, p = 0.05). Egg consumption was found to be significantly associated with a decreased risk of wasting [adjusted RR (95% CI): 0.37 (0.15, 0.89), p = 0.03]. HCZ at 36 months did not differ significantly for children who did and did not receive the mMAD.

CONCLUSION

Meeting the mMAD was associated with better weight-for-height outcomes at 36 months in children in these three LMIC, highlighting the importance of adequate food quantity and quality.

TRIAL REGISTRATION

registered on March 20, 2008.

Social and Non-social Hazard Response in Drivers with Autism Spectrum Disorder

Driving is a complex task that relies on manual, cognitive, visual and social skill. The social demands of driving may be challenging for individuals with Autism Spectrum Disorder (ASD) due to known social impairments. This study investigated how drivers with ASD respond to social (e.g., pedestrians) and non-social (e.g., vehicles) hazards in a driving simulator compared to typically developing drivers. Overall, participants responded faster to social hazards than non-social hazards. It was also found that drivers with typical development reacted faster to social hazards, while drivers with ASD showed no difference in reaction time to social versus non-social hazards. Future work should further investigate how social impairments in ASD may affect driving safety.

Maternal methylmercury exposure through rice ingestion and offspring neurodevelopment: A prospective cohort study

BACKGROUND

Dietary methylmercury intake can occur not only through fish ingestion but also through rice ingestion; however, rice does not contain the same beneficial micronutrients as fish.

OBJECTIVES

In rural China, where rice is a staple food, associations between prenatal methylmercury exposure (assessed using maternal hair mercury) and impacts on offspring neurodevelopment were investigated.

METHODS

A total of 398 mothers were recruited at parturition at which time a sample of scalp hair was collected. Offspring (n=270, 68%) were assessed at 12 months using the Bayley Scales of Infant Development-II, yielding age-adjusted scores for the Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI).

RESULTS

Among 270 mothers, 85% ingested rice daily, 41% never or rarely ingested fish/shellfish and 11% ingested fish/shellfish at least twice/weekly. Maternal hair mercury averaged 0.41μg/g (median: 0.39μg/g, range: 0.079-1.7μg/g). In unadjusted models, offspring neurodevelopment (both MDI and PDI) was inversely correlated with hair mercury. Associations were strengthened after adjustment for fish/shellfish ingestion, rice ingestion, total energy intake (kcal), and maternal/offspring characteristics for both the MDI [Beta: -4.9, 95% Confidence Interval (CI): -9.7, -0.12] and the PDI (Beta: -2.7, 95% CI: -8.3, 2.9), although confidence intervals remained wide for the latter.

CONCLUSIONS

For 12-month old offspring living in rural China, prenatal methylmercury exposure was associated with statistically significant decrements in offspring cognition, but not psychomotor development. Results expose potential new vulnerabilities for communities depending on rice as a staple food.

Home-Based Early Intervention and the Influence of Family Resources on Cognitive Development

OBJECTIVE

To investigate whether early developmental intervention (EDI) can positively affect the trajectories of cognitive development among children from low-resource families.

METHODS

Longitudinal analyses were conducted of data from 293 children in the Brain Research to Ameliorate Impaired Neurodevelopment Home-based Intervention Trial, a randomized controlled trial of a home-based EDI program, to examine trajectories of Bayley Scales of Infant Development-Second Edition Mental Development Index (MDI) scores from 12 to 36 months of age among young children from high- and low-resource families in 3 low- to middle-resource countries.

RESULTS

A 3-way interaction among family resources, intervention group, and age was statistically significant after controlling for maternal, child, and birth characteristics (Wald χ(2)(1) = 9.41, P = .002). Among children of families with high resources, both the intervention and control groups had significant increases in MDI scores over time (P < .001 and P = .002, respectively), and 36-month MDI scores for these 2 groups did not differ significantly (P = .602). However, in families with low resources, the EDI group displayed greater improvement, resulting in significantly higher 36-month MDI scores than the control group (P < .001). In addition, the 36-month MDI scores for children in families with low resources receiving EDI did not differ significantly from children from high-resource families in either the EDI (P = .509) or control (P = .882) groups.

CONCLUSIONS

A home-based EDI during the first 3 years of life can substantially decrease the developmental gap between children from families with lower versus higher resources, even among children in low- to middle-resource countries.

Development of a 12 month screener based on items from the Bayley II Scales of Infant Development for use in Low Middle Income countries

OBJECTIVES

The purpose of the current study was to adapt the Bayley Scales of Infant Development II for use as a screening measure that could be used by health care professionals in Low Middle Income (LMI) countries with 12 month old infants to determine if they needed further assessment and early intervention.

METHODS

The adaptations were made as part of a larger study of children participating in a home-based early intervention program in India, Pakistan, and Zambia. Using Item Response Theory, a brief 12 month screener, with excellent sensitivity and specificity was identified.

RESULTS

The proposed 12 month screener contains 7 mental/cognitive items and 5 motor items. Children who cannot perform more than 3 items on the mental scale (sensitivity 79%, specificity 85%) and/or 3 items on the motor scale (sensitivity 96%, specificity 95%) should be referred for further assessment.

CONCLUSION

This screener can reliably be used to determine if a child needs further developmental assessment.

Development of children at risk for adverse outcomes participating in early intervention in developing countries: a randomized controlled trial

BACKGROUND

Previous research has indicated positive effects of early developmental intervention (EDI) on the development of children in developing countries. Few studies, however, have examined longitudinally when differential treatment effects may be observed and whether differential outcomes are associated with exposure to different risk factors and country of implementation. Also, birth asphyxia as a risk condition has not been well studied. To address these limitations, we conducted a randomized controlled trial to test the hypothesis that there will be differential developmental trajectories favoring those who receive EDI versus a health education intervention in children in rural areas of India, Pakistan, and Zambia.

METHODS

Children with and without birth asphyxia were randomized to EDI or control intervention, which was implemented by parents who received training in biweekly home visits initiated before child age 1 month and continuing until 36 months. Development was assessed in 376 children at ages 12, 24, and 36 months using the Bayley Scales of Infant Development and Ages & Stages Questionnaire administered by evaluators blind to intervention assignment and risk condition.

RESULTS

Longitudinal mixed model analysis indicated that EDI resulted in better development over 36 months in cognitive abilities, regardless of risk condition, maternal resources, child gender, or country. Psychomotor development and parent-reported general development showed similar trends as for cognitive abilities, but were not statistically different between intervention conditions. Developmental differences were observed first at 36 months of age.

CONCLUSION

Early developmental intervention has promise for improving development in children across developing countries when exposed to various risk conditions. EDI should be one prominent approach used to begin to address long-term outcomes and intergenerational transmission of poverty.

Developmental trajectories of children with birth asphyxia through 36 months of age in low/low-middle income countries

BACKGROUND

Resuscitation following birth asphyxia reduces mortality, but may be argued to increase risk for neurodevelopmental disability in survivors.

AIMS

To test the hypothesis that development of infants who received resuscitation following birth asphyxia is not significantly different through 36months of age from infants who had healthy births.

STUDY DESIGN

Prospective observational cohort design comparing infants exposed to birth asphyxia with resuscitation or healthy birth.

SUBJECTS

A random sample of infants with birth asphyxia who received bag-and-mask resuscitation was selected from birth records in selected communities in 3 countries.

EXCLUSION CRITERIA

birth weight<1500g, severely abnormal neurological examination at 7days, mother<15years, unable to participate, or not expected to remain in the target area. A random sample of healthy-birth infants (no resuscitation, normal neurological exam) was also selected. Eligible=438, consented=407, and ≥1 valid developmental assessment during the first 36months=376.

OUTCOME MEASURE(S)

Bayley Scales of Infant Development-II Mental (MDI) and Psychomotor (PDI) Development Index.

RESULTS

Trajectories of MDI (p=.069) and PDI (p=.143) over 3 yearly assessments did not differ between children with birth asphyxia and healthy-birth children. Rather there was a trend for birth asphyxia children to improve more than healthy-birth children.

CONCLUSIONS

The large majority of infants who are treated with resuscitation and survived birth asphyxia can be expected to evidence normal development at least until age 3. The risk for neurodevelopmental disability should not justify the restriction of effective therapies for birth asphyxia.

Randomized trial of early developmental intervention on outcomes in children after birth asphyxia in developing countries

OBJECTIVE

To determine if early developmental intervention (EDI) improves developmental abilities in resuscitated children.

STUDY DESIGN

This was a parallel group, randomized controlled trial of infants unresponsive to stimulation who received bag and mask ventilation as part of their resuscitation at birth and infants who did not require any resuscitation born in rural communities in India, Pakistan, and Zambia. Intervention infants received a parent-implemented EDI delivered with home visits by parent trainers every other week for 3 years starting the first month after birth. Parents in both intervention and control groups received health and safety counseling during home visits on the same schedule. The main outcome measure was the Mental Development Index (MDI) of the Bayley Scales of Infant Development, 2nd edition, assessed at 36 months by evaluators unaware of treatment group and resuscitation history.

RESULTS

MDI was higher in the EDI (102.6 ± 9.8) compared with the control resuscitated children (98.0 ± 14.6, 1-sided P = .0202), but there was no difference between groups in the nonresuscitated children (100.1 ± 10.7 vs 97.7 ± 10.4, P = .1392). The Psychomotor Development Index was higher in the EDI group for both the resuscitated (P = .0430) and nonresuscitated children (P = .0164).

CONCLUSIONS

This trial of home-based, parent provided EDI in children resuscitated at birth provides evidence of treatment benefits on cognitive and psychomotor outcomes. MDI and Psychomotor Development Index scores of both nonresuscitated and resuscitated infants were within normal range, independent of early intervention.

Neurodevelopmental outcomes in infants requiring resuscitation in developing countries

OBJECTIVE

To determine whether resuscitation of infants who failed to develop effective breathing at birth increases survivors with neurodevelopmental impairment.

STUDY DESIGN

Infants unresponsive to stimulation who received bag and mask ventilation at birth in a resuscitation trial and infants who did not require any resuscitation were randomized to early neurodevelopmental intervention or control groups. Infants were examined by trained neurodevelopmental evaluators masked to both their resuscitation history and intervention group. The 12-month neurodevelopmental outcome data for both resuscitated and non-resuscitated infants randomized to the control groups are reported.

RESULTS

The study provided no evidence of a difference between the resuscitated infants (n = 86) and the non-resuscitated infants (n = 115) in the percentage of infants at 12 months with a Mental Developmental Index <85 on the Bayley Scales of Infant Development-II (primary outcome; 18% versus 12%; P = .22) and in other neurodevelopmental outcomes.

CONCLUSIONS

Most infants who received resuscitation with bag and mask ventilation at birth have 12-month neurodevelopmental outcomes in the reference range. Longer follow-up is needed because of increased risk for neurodevelopmental impairments.

Characteristics of HIV-infected mothers associated with increased risk of poor mother-infant interactions and infant outcomes

INTRODUCTION

The current study aimed to investigate the relationship between individual and familial characteristics of HIV-infected mothers and their psychological health as it relates to parenting as well as their parenting beliefs/abilities.

METHOD

A descriptive correlational design was used. Seventeen HIV-infected mothers and their infants were recruited from a university clinic in Alabama. Assessments were gathered at the infant's pediatric clinic appointments (approximately 6 weeks after delivery) and included a demographic questionnaire, the Beck Depression Inventory-II, the Maternal Confidence Questionnaire, the Parenting Stress Index-Short Form, and the Questionnaire About Physical Contact.

RESULTS

Dysfunctional parent-child interactions significantly correlated with maternal confidence, parent stress, and overall feeling about physical contact. Difficult child temperament correlated with overall and current feelings of physical contact and parent stress. Significant correlations were found between parent distress, parent stress, and maternal depression.

DISCUSSION

Beyond the need to assist HIV-infected mothers with stress and depression, an intervention is needed to facilitate optimal parent-child interactions and improve both child psychosocial and cognitive outcomes.

Avatar assistant: improving social skills in students with an ASD through a computer-based intervention

This study assessed the efficacy of FaceSay, a computer-based social skills training program for children with Autism Spectrum Disorders (ASD). This randomized controlled study (N = 49) indicates that providing children with low-functioning autism (LFA) and high functioning autism (HFA) opportunities to practice attending to eye gaze, discriminating facial expressions and recognizing faces and emotions in FaceSay's structured environment with interactive, realistic avatar assistants improved their social skills abilities. The children with LFA demonstrated improvements in two areas of the intervention: emotion recognition and social interactions. The children with HFA demonstrated improvements in all three areas: facial recognition, emotion recognition, and social interactions. These findings, particularly the measured improvements to social interactions in a natural environment, are encouraging.

Mediating factors associated with pedestrian injury in children with attention-deficit/hyperactivity disorder

OBJECTIVE

Unintentional injury is the leading cause of pediatric mortality. One leading cause of unintentional injury is pedestrian injury. Children with developmental disabilities, particularly those with attention-deficit/hyperactivity disorder-combined type (ADHD-C) seem to have increased pedestrian injury risk. This study examined (1) the differences in pedestrian behavior between children with ADHD-C and normally developing comparison children and (2) the mediating factors that might link ADHD-C with pedestrian injury risk.

PATIENTS AND METHODS

A total of 78 children aged 7 to 10 years (39 children with ADHD-C diagnoses and 39 age- and gender-matched typically developing children) participated. The main outcome measure was pedestrian behavior, as measured in a semi-immersive, interactive, virtual pedestrian environment. Key pedestrian variables related to different aspects of the crossing process were identified: (1) before the cross (ie, evaluating aspects of the crossing environment); (2) making the cross (ie, deciding to cross and initiating movement); and (3) safety of the cross (ie, safety within the pedestrian environment after the decision to cross was made).

RESULTS

Children with ADHD-C chose riskier pedestrian environments to cross within (F(1,72) = 4.83; P < .05). No significant differences emerged in other aspects of the crossing process. Executive function played a mediating role in the relationship between ADHD-C and the safety of the cross.

CONCLUSIONS

Children with ADHD-C seem to display appropriate curbside pedestrian behavior but fail to process perceived information adequately to permit crossing safely.

Outcomes of a massage intervention on teen mothers: a pilot study

The difficulties that adolescent mothers encounter as a result of the combined stress of adolescence, parenthood, maintaining peer relationships, and establishing positive relationships with their infants have been identified in the literature, and these characteristics are often associated with poor infant outcomes. This study was designed to examine the effects of an infant massage intervention on adolescent mothers' attitudes and perceptions of their infants. Twenty-five African-American adolescent mothers (mean age 16.13 years), who were enrolled in a parent training program for high school students in a southern state, participated in the project. The mothers were assigned randomly to an intervention (9) or control group (16). After a brief training session, participants in the intervention group practiced massage with their infants for approximately 2 months. Data analysis was based on the 15 participants who completed both baseline and 2-month follow-up measures (8 in the control group and 7 in the intervention group). This study found some support for teaching infant massage to adolescent mothers as a way of enhancing maternal-infant physical contact and lowering depression, as well as positively influencing mothers' perceptions of infant temperament. Results indicate that infant massage training may lead to improvements beyond those achieved with a typical parent education curriculum and shows potential as a low-cost supplement to current teen mother education in high schools.

Clinical comparison of the visual parameters in infants with intrauterine growth retardation vs. infants with normal birth weight

We measured vision function in a number of 7-month-old infants with intrauterine growth retardation (IUGR) and compared these findings to those for 7-month-old infants of normal birth weight. The IUGR infants had an average visual acuity of 6/162 (20/540) and an average spherical refractive error of 1.49 D hyperopia. The normal birth weight infants had an average visual acuity of 6/118.8 (20/396) and an average spherical refractive error of 0.94 D hyperopia. However, the differences between the infant groups for visual acuity and refractive error were not statistically significant. Anisometropia, astigmatism, and strabismus were infrequent for both infant groups. The results of this study suggest that IUGR infants have visual abilities resembling those of normal birth weight infants.

Comparison and message-formulation skills in the referential communication of severely mentally retarded children

The importance of comparison and message-formulation skills in referential communication was studied with severely mentally retarded children. A store game task was used that required the child to communicate a choice of one or two objects on a shelf. Comparison training taught the children to select the appropriate object when paired with a similar but inappropriate object. Message training taught the children to communicate by pointing and/or gesturing. Results indicated that combined comparison and message training produced higher communication accuracy than did comparison training alone. Comparison training, however, increased subjects' accuracy of communicating as compared to an untrained control group. A parallel pattern of results was found for communication frequency. The training groups either maintained or improved their communicative performance in a near-generalization task, suggesting that they learned communicative behavior and not merely task-specific behavior.

The effect of communicative demands on request-making in the moderately and severely mentally retarded

Two experiments were reported investigating the conditions that elicit request-making in the moderately and the severely mentally retarded. In both experiments single-subject designs were used with a store game task designed to closely approximate a naturalistic communication situation. In the first experiment moderately retarded adults were able to consistently communicate which of two objects they wished to obtain from a store counter. In the second, severely retarded adolescents initially made some errors but communicated effectively on 100% of the trials by the end of the experiment. These results contrast markedly with the results from the less naturalistic task used previously. In both experiments the amount of verbalization was greater when the task was arranged to create a demand for communication. Applications of these findings to everyday communicative situations involving the mentally retarded are discussed.