Mihela Erjavec

DO INFANTS SHOW GENERALIZED IMITATION OF GESTURES? II. THE EFFECTS OF SKILLS TRAINING AND MULTIPLE EXEMPLAR MATCHING TRAINING

The determinants of generalized imitation of manual gestures were investigated in 1- to 2-year-old infants. Eleven infants were first trained eight baseline matching relations; then, four novel gestures that the infants did not match in probe trials were selected as target behaviors. Next, in a generalized imitation test in which matching responses to baseline models were intermittently reinforced, but matching responses to target models were not eligible for reinforcement, the infants matched baseline models but not the majority of their target behaviors. To ensure their failure to match the target behaviors was not due to motor constraints, the infants were trained, in a multiple-baseline procedure, to produce the target responses under stimulus control that did not include an antecedent model of the target behavior. There was no evidence of generalized imitation in subsequent tests. When the infants were next trained to match each target behavior to criterion (tested in extinction) in a multiple-baseline-across-behaviors procedure, only 2 infants continued to match all their targets in subsequent tests; the remaining infants matched only some of them. Seven infants were next given mixed matching training with the target behaviors to criterion (tested in extinction); they subsequently matched these targets without reinforcement when interspersed with trials on which matching responses to baseline models were intermittently reinforced. In repeat tests, administered at 3-week intervals, these 7 children (and 2 that did not take part in mixed matching training) continued to match most of their target behaviors. The results support a trained matching account, but provide no evidence of generalized imitation, in 1- to 2-year-old infants.

Validity and reliability of the Fitbit Zip as a measure of preschool children’s step count

Objectives Validation of physical activity measurement tools is essential to determine the relationship between physical activity and health in preschool children, but research to date has not focused on this priority. The aims of this study were to ascertain inter-rater reliability of observer step count, and interdevice reliability and validity of Fitbit Zip accelerometer step counts in preschool children. Methods Fifty-six children aged 3–4 years (29 girls) recruited from 10 nurseries in North Wales, UK, wore two Fitbit Zip accelerometers while performing a timed walking task in their childcare settings. Accelerometers were worn in secure pockets inside a custom-made tabard. Video recordings enabled two observers to independently code the number of steps performed in 3 min by each child during the walking task. Intraclass correlations (ICCs), concordance correlation coefficients, Bland-Altman plots and absolute per cent error were calculated to assess the reliability and validity of the consumer-grade device. Results An excellent ICC was found between the two observer codings (ICC=1.00) and the two Fitbit Zips (ICC=0.91). Concordance between the Fitbit Zips and observer counts was also high (r=0.77), with an acceptable absolute per cent error (6%–7%). Bland-Altman analyses identified a bias for Fitbit 1 of 22.8±19.1 steps with limits of agreement between −14.7 and 60.2 steps, and a bias for Fitbit 2 of 25.2±23.2 steps with limits of agreement between −20.2 and 70.5 steps. Conclusions Fitbit Zip accelerometers are a reliable and valid method of recording preschool children’s step count in a childcare setting.

The Parent Infant Play Observation code (PIPOc): development and testing of a new positive parenting measure

Objective: To develop a new observational code of parents playing with their infant in the first 18 months. Background: There is a lack of observational codes to analyse early interactions between parents and infants. We developed and tested this measure – the Parent Infant Play Observation code (PIPOc) – to be developmentally appropriate for infants, brief and easy to code after training, reliable and potentially suitable for clinical and research use. Method: The PIPOc was developed for use in a repeated measures trial of a new parenting programme. Mothers were filmed at home playing with their infant for 10 minutes with a six-month follow-up visit. The author also collected IT-HOME inventory data at the homes. A coding manual was developed to train an independent coder. Results: Six positive parenting behaviours were coded (Talk, Play, Touch, Move, Mind and Respond) with excellent to very good inter-rater reliability between the author and independent coder. Principal component analysis of the coded behaviours resulted in a three-component model termed -positive physical encouragement, sensitive parenting and verbal engegement components. A further analysis for the scores at follow-up resulted in the same component solution. Concurrent validity of the three components with subscale scores from the IT-HOME inventory subscales is reported. Conclusions: The PIPOc shows promising psychometric properties which are robust and reliable over six months. More extensive use of the PIPOc observation scores comparing intervention and control parents’ scores on the observation components will further test the code’s sensitivity to change over time.

The impact of body-part-naming training on the accuracy of imitative performances in 2- to 3-year-old children.

A series of three experiments explored the relationship between 3-year-old childrens ability to name target body parts and their untrained matching of target hand-to-body touches. Nine participants, 3 per experiment, were presented with repeated generalized imitation tests in a multiple-baseline procedure, interspersed with step-by-step training that enabled them to (i) tact the target locations on their own and the experimenters bodies or (ii) respond accurately as listeners to the experimenters tacts of the target locations. Prompts for on-task naming of target body parts were also provided later in the procedure. In Experiment 1, only tact training followed by listener probes were conducted; in Experiment 2, tacting was trained first and listener behavior second, whereas in Experiment 3 listener training preceded tact training. Both tact and listener training resulted in emergence of naming together with significant and large improvements in the childrens matching performances; this was true for each child and across most target gestures. The present series of experiments provides evidence that naming--the most basic form of self-instructional behavior--may be one means of establishing untrained matching as measured in generalized imitation tests. This demonstration has a bearing on our interpretation of imitation reported in the behavior analytic, cognitive developmental, and comparative literature.