Co-morbidity of crying and feeding problems with sleeping problems in infancy: Concurrent and predictive associations

The co-morbidity of crying, feeding and sleeping problems at 5 months of age was investigated in a representative sample of 432 infants in South Germany. A crying, sleeping or feeding problem was reported in 32.7% of these infants by their parents and a further 14.6% had two or more of these problems. Little co-morbidity between crying and feeding problems was found. There were moderate to strong associations between crying and sleeping behaviours. Feeding problems showed little relationship to sleeping behaviour, but feeding type and frequency of feeds were related to night waking. Breastfed infants woke much more often at night. Crying and feeding problems at 5 months were poor predictors of sleeping behaviour at 20 or 56 months of age. Later sleeping behaviour was best predicted by infant sleeping behaviour. At 56 months, maternal distress due to sleeping and co-sleeping practices was predicted by maternal distress due to crying and feeding practices at 5 months of age. The predictions were significant but generally weak to modest in strength. Future studies on the consequences of crying or feeding problems should take into account patterns of co-morbidity. So-called ‘post-colicky’ sleep problems are not due to increased crying per se but rather appear to be the consequence of associated infant sleeping problems and parental caretaking patterns for dealing with night waking in infancy.     

USE OF EXTINCTION AND REINFORCEMENT TO INCREASE FOOD CONSUMPTION AND REDUCE EXPULSION

Extinction and reinforcement contingencies were used to treat 2 children with feeding disorders. Positive reinforcement and avoidance extinction effectively increased food acceptance but also increased food expulsion. Reduced expulsion and increased swallowing were achieved by repeated presentation of expelled food, a second extinction component.     

BEHAVIORAL ASSESSMENT AND TREATMENT OF CHRONIC FOOD REFUSAL IN HANDICAPPED CHILDREN

In this study, we examined the eating behavior of four handicapped children, none of whom exhibited self-feeding skills. All children had a history of food refusal and were nutritionally at risk; one child received all nourishment by way of a gastrostomy tube. Baseline data taken during mealtimes indicated that all children accepted very little food, expelled food frequently, and engaged in a number of disruptive behaviors. Treatments consisted of one or more of the following contingent events: social praise, access to preferred foods, brief periods of toy play, and forced feeding. Results of multiple-baseline and reversal designs showed marked behavioral improvement for each child and increases in the amount of food consumed. Further improvements were noted at follow-up, which ranged from 7 to 30 months posttreatment.     

Context and companion's behavior as determinants of cooperation and competition in school-age children

Information about the social context and a companion's actions were studied as determinants of cooperation and competition in middle childhood. In Experiment 1, first-, third-, and fifth-grade children were told that they would play a board game with another same-age, same-sex child (actually a bogus companion). The experimenter's instructions established shared rewards or winner-take-all as outcome conditions. Preprogrammed responses—100% cooperative or 100% competitive—provided information about the companion's actions. Results revealed that the companion's responses alone determined cooperation and competition among the first graders. Third graders used both types of information. Fifth graders, however, demonstrated a bias to respond cooperatively whenever a cooperative cue was present. In Experiment 2, first-grade subjects were given extra rehearsal of the game strategies, a scorekeeping procedure for use during the game, or a combination of the two. Results indicated that, under these conditions, younger subjects were able to use the instructions about reward distribution as well as the companion's actions in guiding their social behavior.     

Quantification of rats' behavior during reinforcement periods

What is treated as a single unit of reinforcement often involves what could be called a reinforcement period during which two or more acts of ingestion may occur, and each of these may have associated with it a series of responses, some reflexive, some learned, that lead up to ingestion. Food-tray presentation to a pigeon is an example of such a “reinforcement period.” In order to quantify this behavior, a continuous-reinforcement schedule was used as the reinforcement period and was chained to a fixed-ratio schedule. Both fixed-ratio size and reinforcement-period duration were manipulated. Rats were used as subjects, food as reinforcement, and a lever press as the operant. Major findings included (a) a rapid decline in response rates during the first 15 to 20 seconds of the reinforcement periods, and (b) a strong positive relationship between these response rates and the size of the fixed ratio. Also revealed was a short scallop not normally found in fixed-ratio response patterns, whose length was a function of fixed-ratio size and reinforcement-period duration. It is suggested that rapidly fluctuating excitatory processes can account for many of these findings and that such processes are functionally significant in terms of behavioral compensation.     

Speech acquisition in a nonverbal isolate child

The present study attempted to evaluate experimentally the relationship between two response classes: cooperative play and speech. One child was observed in a preschool free-play setting. Base rates of speech and play with peers indicated that the child never spoke to or played with peers during free-play periods. Base rates of teacher attention were observed to fluctuate directly with the child's isolate play. When differential attention and extinction operations were presented, removed and presented again, the frequency of cooperative play with peers increased, decreased and increased accordingly. Moderate fluctuations in verbal behavior also correlated with the presence and absence of the differential attention and extinction operations, even though the operations were applied only to cooperative play. The results suggest that some nonverbal isolate children may begin producing speech when play behaviors with peers are reinforced by teachers.     

Sensitivity to binocular depth information in infants

In order to study infants' sensitivity to binocular information for depth, 11 infants, 20 to 26 weeks of age, were presented with real and stereoscopically projected virtual objects at three distances, and the infants' reaching behavior was videotaped. When the virtual object was positioned out of reach, infants tended to lean further forward and to reach less frequently than when the virtual object was positioned within reach. In addition, the proportion of reaches in which the infants patted, closed their hands, or brought their hands together was greater when the virtual object was within reach. However, no difference in the terminal location of the infants' reaches was found as a function of the virtual object's position. Examination of reaches to a near real object revealed that infants frequently did not contact the object or show appropriate hand shape or orientation. The effectiveness of the cue of retinal size and of binocular information for the depth of an object is discussed. It is concluded that 5-month-old infants are sensitive to binocular information for depth.     

Age trends in children's time-sharing performance

To investigate developmental differences in time-sharing performance, 60 boys, 20 in each of three age groups (7-, 10-, and 13-year-olds) performed an auditory matching task and a tracking task alone and concurrently, the latter under two sets of instructions. Decrements produced by concurrent performance were compared for the three age groups. When the time-shared tasks were presented as equally important, time-sharing produced significantly greater proportional decrements in the tracking performance of the younger children and for all age groups tracking task decrements were directly related to matching task difficulty. Subsequently, the children were instructed that one or the other of the tasks was more important and that they were to improve their performance on that task. All three age groups showed a significant improvement on the task emphasized by instructions. The relationship of the results to two models of information processing is discussed.     

Changes in feeding and foraging patterns as an antipredator defensive strategy: a laboratory simulation using aversive stimulation in a closed economy.

The effects of the risk of electric shock on the meal patterns of rats living in an operant chamber were investigated. Rats could obtain food by working on a response lever that provided reinforcement according to chained fixed-ratio continuous reinforcement schedules that allowed the animals control over meal size. Using a two-compartment operant chamber with a safe nesting area and manipulanda area with a grid floor, shock could be correlated with responding on the schedule. Shocks (less than or equal to 1.25 per hour) were scheduled to occur randomly throughout the day, independent of the rat's behavior. Shock caused a reorganization of meal patterns such that the animals took less frequent but larger meals. This pattern reduced the time the animals spent at risk without compromising caloric balance. Similar changes in feeding pattern were obtained in both hooded and albino rats. Exposure to shock in a separate chamber did not produce these behavioral modifications. The magnitude of shock-induced alterations of meal patterns was greater with chained fixed-ratio 90 continuous reinforcement than with chained fixed-ratio 10 continuous reinforcement. Additionally, the rats seemed to be able to reduce food intake but increase caloric efficiency, such that the reduced food intake did not have deleterious effects on maintenance of body weight. These behavioral modifications reduced the number of shocks received from that which would have been expected if meal pattern changes had not occurred. We suggest that this technique may provide a useful laboratory simulation of the impact that the risk of predation has on foraging behavior.