Older siblings as potential supervisors of younger siblings: sibling supervisors' recognition of injury-risk behaviours and beliefs about supervisee risk taking and potential injury outcomes.

BACKGROUND: Past research has shown that increased injury risk for supervisees during sibling supervision is in part due to the supervision practices of older siblings. METHODS: The current study used a photo sorting task to examine older siblings' recognition of injury-risk behaviours, their perceived likelihood of supervisees engaging in, or being injured while engaging in, these behaviours, and awareness of past risk-taking behaviours of supervisees. Mothers completed the same measures and an interview about sibling supervision in the home. RESULTS: Mothers reported that sibling supervision occurred most frequently in the kitchen, living room, and children's bedrooms, for approximately 39 min/day, and that the more time the children spent together in a room, the more frequently the older sibling supervised the younger one. The most common reasons mothers gave for why sibling supervision was allowed included beliefs that the older child knows about hazards and unsafe behaviours and that the child could provide adequate supervision. Photo sort results revealed that older siblings were able to correctly identify about 98% of risk behaviours, with these scores significantly higher than what mothers expected (79%). However, compared with mothers, older siblings were less aware of risk behaviours that their younger siblings had engaged in previously. In addition, mothers rated supervisees as 'fairly likely' both to engage in risk behaviours and to experience an injury if they tried these behaviours, whereas sibling supervisors rated both supervisee risk behaviour and injury outcomes as 'not likely' to occur. CONCLUSION: Older siblings showed good knowledge of hazards but failed to realize that younger children often engage in injury-risk behaviours. Efforts to improve the supervision practices of sibling supervisors need to include changing their perception of supervisees' injury vulnerability and potential injury severity, rather than targeting to increase knowledge of injury-risk behaviours per se.

Identifying predictors of medically-attended injuries to young children: do child or parent behavioural attributes matter?

OBJECTIVE: To investigate whether one can differentiate injured and uninjured young children based on child behavioural attributes or indices of caregiver supervision. METHOD: A matched case-control design was used in which case participants were children presenting to an emergency department for treatment for an injury and age/sex matched control participants presented for illness-related reasons. During structured phone interviews about supervision parents reported on general supervisory practices (standardised questionnaire) and specific practices corresponding to time of injury (cases) or the last time their child engaged in the activity that incited their match's injury (controls). Parents also reported on child behavioural attributes that have been linked to child risk taking in prior research (inhibitory control, sensation seeking). RESULTS: Results revealed no group differences in child behavioural attributes; however, the control group received more supervision both in general (OR = 4.82, 95% CI 1.89 to 12.33) and during the specified activity that led to injury in cases (OR = 5.38, 95% CI 2.13 to 13.58). CONCLUSION: These findings confirm past speculation that caregiver supervision influences children's risk of medically-attended injury and highlight the importance of targeting supervision in child-injury prevention interventions.

Once bitten, twice shy? Medically-attended injuries can sensitise parents to children's risk of injuries on playgrounds.

OBJECTIVE: To compare risk perceptions of parents whose child sustained a medically attended playground injury (cases) with those of parents whose child had not (controls) to address two questions. Does having a child experience a medically attended injury: (1) sensitise parents to children's injury vulnerability and severity; (2) influence parents' appraisal of the injury mechanism (child's behaviour), attributions for injuries or beliefs about strategies for prevention? METHOD: Each case-control parent dyad was assigned to one of two conditions: (1) being presented with 10 common injury-risk playground behaviours specific to the equipment on which their child had been hurt, and asked to appraise injury vulnerability and severity; or (2) being presented with scenarios about playground injuries that varied in severity but were all based on the same child behaviour, and asked questions about this behaviour, attributions for injury and strategies for prevention. RESULTS: The results support the occurrence of a sensitisation process. Compared with control parents, case parents showed higher ratings of injury severity and children's vulnerability to injury, made fewer attributions for injuries to bad luck, and endorsed a greater diversity of prevention strategies, including parent (closer supervision), child (teaching rules about safe play on playgrounds) and environmental (modifications to playgrounds). CONCLUSIONS: A child's medically attended injury can create a "teachable moment" for the parent. Linking injury-prevention programming to this teachable moment may increase the likelihood of evoking changes in parental supervisory behaviour and their setting of rules limiting their child's risk behaviours to reduce the occurrence of childhood injury.

School-age children's safety attitudes, cognitions, knowledge, and injury experiences: how do these relate to their safety practices?

BACKGROUND: A variety of factors affect the safety and risk practices of school-age children, but rarely have multiple factors been considered simultaneously. OBJECTIVE: To examine children's safety attitudes and cognitions more thoroughly and assess how these factors, along with children's safety knowledge and injury experiences, relate to children's safety practices. METHODS: Over several classroom sessions, boys and girls in two age groups (7-9, 10-12 years) completed a psychometrically sound questionnaire that indexes their behaviors, attitudes, cognitions, knowledge, and injury experiences. RESULTS: Fewer safety practices were reported by older than younger children and boys than girls. Children's attitudes, cognitions, knowledge, and injury experiences each correlated with safety practices, but only safety attitudes and injury experiences predicted practices in a multivariate model. CONCLUSION: Exploring the relative influence of numerous factors on safety practices highlights the important role that attitudes play in predicting children's safety practices. Implications of these results for injury prevention programming are discussed.

Size of critical band in infants, children, and adults.

Masked thresholds at two signal frequencies (0.8 and 4 kHz) were obtained from listeners aged 6.5 months, 2 years, 5 years, and 20.5 years in the presence of constant spectrum level, narrowband maskers of differing bandwidths. Consistent with the classical results of Fletcher (1940), masked threshold for all age groups increased with bandwidth up to a critical width, beyond which further increases in bandwidth were ineffective in increasing threshold. These critical widths (estimates of critical band size) did not change substantially with age (critical widths for infants were no more than 50% larger than those of adults) despite substantial changes in masked thresholds with age. Thus, contrary to previous claims, changes in auditory filter width cannot account for developmental changes in masked or absolute thresholds.

Development of the perception of musical relations: semitone and diatonic structure.

In the present research we examined the development of sensitivity to two musical relations significant in Western tonal music, the semitone and diatonic structure. Infants and preschool children were tested for their detection of a semitone change in any position of a five-note melody. Two standard melodies were used, one composed of diatonic tones only and the other containing a non-diatonic tone. In Experiment 1, children from 4 to 6 years of age were superior in detecting the semitone change in the diatonic context compared with the nondiatonic context. In Experiment 2, infants 9 to 11 months of age detected the semitone change in all positions, but their performance was not influenced by diatonic context. These findings indicate that infants and children can discriminate a semitone in a musical context and that the priority of diatonic structure emerges by 4 to 6 years of age.

A community-based study of parents' knowledge, attitudes and beliefs related to childhood injuries.

This study assessed parents' knowledge of injury risks for children, attitudes within children's injury-risk behaviours, and beliefs related to a number of aspects of childhood injuries. Parents completed questionnaires and participated in discussions using scenarios depicting child-injury situations that involved a parent and child. Results indicated that parents view injuries largely as a natural consequence of childhood and they believe children learn about risk avoidance from injury experiences. Parents' responses did not indicate a strong belief that injuries to children are preventable or that they should assume primary responsibility for preventing injuries to children. Parents readily identified potential injury consequences and alternative behaviours but provided a number of rationales for making choices that place their child at injury risk: explanations related to convenience, minimizing stress, placing their own goals as a priority, and believing they can keep the child safe in a hazardous situation. Injury prevention programming that targets parents needs to focus on increasing awareness of the scope of the problem and altering attitudes and beliefs related to prevention.

Prevention of paediatric acquired brain injury: an interactive, elementary-school program.

Responding to a gap in existing programs that aim to prevent spinal cord and brain injuries among children, an interactive activity-based program was developed and implemented through local elementary schools, focusing on children 8 to 10 years of age. Evaluation involved a pretest/post-test design with a comparison group who had not experienced the program. Children who participated in the program showed increases in knowledge, self-reported changes in behaviour, and favourable shifts in attitudes about vulnerability to injury four months after exposure to the program. Control group children responded similarly to how children in the intervention group responded on the pretest measure.

Visual feedback and anticipatory hand orientation during infants' reaching.

Infants 5, 7, and 9 mo. of age were videorecorded while reaching for a dowel that either was stationary or changed orientation after initiation of a reach. Visual fixation and hand orientation were monitored throughout each reach, as was the efficiency with which infants contacted the stimulus. In reaching for the stationary stimulus, the 5-mo.-olds showed significantly poorer hand orientation adjustment throughout their reach than 9-mo.-olds. The 7-mo.-olds began a reach with the hand poorly oriented as did 5-mo.-olds, but just before object contact their performance matched that of the 9-mo.-olds. On change-orientation trials, the 5-mo.-olds' reaching was disrupted. They missed, stopped, or withdrew their reach on over half of these trials, and hand orientation on contact was significantly worse than on no-change trials. By contrast, older infants were more skilled in using visual feedback to make corrective adjustments in hand orientation during execution of the reach to secure a smooth contact with the stimulus. These infants showed no difference in hand orientation on contact for change in comparison to no-change trials. The 9-mo.-olds' performance surpassed that of the 7-mo.-olds only in the efficiency with which they contacted the stimulus and the incidence of grasps on first contact.

Stimulus-presentation probability influences newborns' head orientation to sound.

Although newborn infants are capable of turning their heads toward laterally-presented sounds, the incidence of such responding varies across studies. Previous work suggests that as the probability of a laterally-presented sound increases head-turning performance improves. To test this "lateral-stimulus-presentation probability" hypothesis, we presented 30 alert newborns with a rattle sound from a lateral source on either 1/4, 2/4, or 3/4 of all sound trials. On remaining sound trials the rattle came from a loudspeaker located above the infant's head. For 12 infants all lateral trials were presented consecutively; these trials were spaced across the session for the other infants. The likelihood of correct head turning increased linearly as the lateral-stimulus-presentation probability increased. The distribution of lateral trials did not influence the incidence of correct head turning.

The Parent Supervision Attributes Profile Questionnaire: a measure of supervision relevant to children's risk of unintentional injury.

OBJECTIVE: To further establish the psychometric properties of the Parent Supervision Attributes Profile Questionnaire (PSAPQ), a questionnaire measure of parent supervision that is relevant to understanding risk of unintentional injury among children 2 through 5 years of age. METHODS: To assess test-retest reliability, parents completed the PSAPQ twice, with a one month interval. Internal consistency estimates for the PSAPQ were also computed. Confirmatory factor analyses were applied to the data to assess the four factor structure of the instrument by assessing the convergent and divergent validity of the subscales and their respective items. RESULTS: Test-retest reliability and internal consistency scores were good, exceeding 0.70 for all subscales. Factor analyses confirmed the hypothesized model--namely that the 29 item questionnaire comprised four unique factors: protectiveness, supervision beliefs, risk tolerance, and fate influences on child safety. CONCLUSIONS: Previous tests comparing the PSAPQ with indices of actual supervision and children's injury history scores revealed good criterion validity. The present assessment of the PSAPQ revealed good reliability (test-retest reliability, internal consistency) and established the convergent and divergent validity of the four factors. Thus, the PSAPQ has proven to have strong psychometric properties, making it a unique and useful measure for researchers interested in studying links between supervision and young children's risks of unintentional injury.

Infants' localization of sounds in the median sagittal plane: effects of signal frequency.

The purpose of this research was to determine if infants, like adults, show differential localization performance in the median sagittal plane (MSP) as a function of the spectrum of the signal. Infants 6-18 months of age were seated in a dark room facing an array of nine loudspeakers, with one loudspeaker positioned at ear level, 0 degrees, and four each positioned above and below ear level at 4 degrees, 8 degrees, 12 degrees, and 16 degrees. A two-alternative, forced-choice procedure was used in which a sequence of noise bursts was presented at 0 degrees and then shifted vertically, above or below 0 degrees, and continued to be presented until the infant made a directional head and/or eye movement; correct responses were visually reinforced. For each of three bandpass noise conditions (less than 4 kHz, 4-8 kHz, 8-12 kHz), minimum audible angle (MAA) for each listener, i.e., the smallest of the four angular shifts in vertical sound location that the listener could reliably detect, was estimated. Results indicated that MAA systematically decreased with increasing age, revealing an increasingly finer partitioning of auditory space. Moreover, performance at each age revealed the importance of high frequencies for localization in the MSP. Infants did not reliably localize the low-pass signal (less than 4 kHz) and showed the best performance to the signal comprising the highest frequencies (8-12 kHz). These findings reveal systematic age-related improvements in sound localization abilities during infancy, and suggest that spectral cues similar to those for adults operate for infants in vertical localization.

Do children's intentions to risk take relate to actual risk taking?

OBJECTIVES: Concerns about safety and rigorous ethic standards can make it very difficult to study children's risk taking. The goal of this study was to determine how closely intentions to risk take relate to actual risk taking among boys and girls 6-11 years of age. METHODS: Children initially completed an "intentions to risk take" task. Following administration of several questionnaires they later participated in an actual risk taking task. RESULTS: At all ages, for both boys and girls, intentions to risk take was highly positively correlated with actual risk taking. When discrepancies occurred these were usually of minimal magnitude. CONCLUSIONS: Tasks that tap children's intentions to risk take can serve as proxy indicators of children's actual risk taking.

Children's perspectives on injury and close-call experiences: sex differences in injury-outcome processes.

Compared boy's and girls' self-reports of injuries and close calls, using a structured telephone interview that was conducted each of 14 days to obtain reports of antecedent events (past memories of similar injuries, immediate injury context), attributions of blame (own behavior, other's behavior, bad luck), ratings of injury severity, telling parents about injuries, and the factors that influence children's learning to avoid injury-risk behaviors. In comparison to girls, boys reported more injuries and close calls, were more likely to be with peers when injured, were more likely to repeat behaviors that had resulted in prior injuries, were more likely to erroneously attribute injuries to bad luck, were more likely to rate injuries as low in severity, and were less likely to tell their parents about these events.

Infants' monaural localization of sounds: effects of unilateral ear infection.

The aim in this study was to examine the impact of unilateral ear infection (i.e., otitis media with effusion) on infants' localization of sounds in the horizontal place. Twenty eight infants 6 to 18 months of age were tested at the time of an ear infection, as well as 2 weeks later. Sound localization was measured using a two-alternative forced-choice procedure to examine infants' abilities to discriminate a sound shift of 8 degrees, 12 degrees, 16 degrees, and 20 degrees off midline and along the horizontal axis, either ipsilateral or contralateral to the infected ear. A head and/or eye movement in the direction of the sound was designated as a correct response and was visually reinforced. Results revealed significant negative effects of unilateral ear infection on sound localization performance. All infants showed more correct localization responses for sounds shifted ipsilateral to the problem ear 2 weeks following their ear infection than at the time of the infection. Localization of sounds shifted contralateral to the infected ear did not vary with test date, and significantly exceeded ipsilateral performance when tested at the time of an ear infection. Results are consistent with adult data which indicates that, with unilateral hearing loss, a sound ipsilateral to the problem ear is displaced in location along the horizontal axis toward the well-functioning ear. These findings indicate the importance of balanced binaural functioning for horizontal localization and highlight the plasticity of the developing human auditory system.

Infants' localization of sounds in the horizontal plane: effects of auditory and visual cues.

Infants 6, 9, 12, 15, and 18 months were seated in a dark room facing a semicircular array comprising 10 loudspeakers, 5 to their right and left at 18 degrees, 36 degrees, 54 degrees, 72 degrees, and 90 degrees from midline. Each infant received 2 types of trials: auditory-alone trials (only a sequence of 8 clicks played), and auditory-visual trials (following the first 4 clicks, a light display at the location of the loudspeaker was activated and remained on for the remaining 4 clicks). Calibration markers on the infant's head were used to measure azimuth error (i.e., the discrepancy between the angle of head turn and loudspeaker location). For auditory-visual trials, all infants turned their head within 4 degrees-6 degrees of the sound source; there was no effect of age or loudspeaker location. For auditory-alone trials, there were significant age differences in performance, with a systematic decrease in discrepancy angle with increasing age. By 18 months there was no difference in performance as a function of localization cue.

Infants' localization of sounds in the median vertical plane: estimates of minimum audible angle.

Infants 6, 9, 12, 15, and 18 months of age were seated in a dark room directly facing an array of nine loudspeakers positioned along the median vertical plane. One loudspeaker was positioned at ear level, 0 degree, and four others each were positioned above and below 0 degree. To examine infants' resolution of auditory space in the median vertical plane we sought to determine the smallest angular shift in the vertical location of a sound that infants could reliably detect (i.e., minimum audible angle). A two-alternative forced-choice procedure was used in which a sequence of white noise bursts was presented initially at 0 degree, and then shifted vertically (i.e., above or below 0 degree) and continued to be presented until the infant made a directional response; correct responses were visually reinforced. The smallest angular shift in vertical location that was reliably detected systematically decreased with increasing age between 6 months (15 degrees) and 18 months (4 degrees), suggesting a finer partitioning of auditory space along the vertical axis over this age range. By 18 months infants' performance matched that of a group of adults tested under the same circumstances.

Sibling power: influence of older siblings' persuasive appeals on younger siblings' judgements about risk taking behaviours.

OBJECTIVES: Although many injuries happen when school age children are away from home and in the company of other children, we know surprisingly little about interpersonal influences on children's risk taking decisions. The aim of the present study was to examine the influence of older siblings' persuasive appeals on young children's decisions about engaging in behaviours that could threaten their physical safety. METHODS: Forty same sex sibling pairs participated. Children were shown drawings of play scenes (bicycling, river crossing, and sledding), with each depicting lower and higher risk paths of travel. Children of 8 years made initial decisions as to which paths they would take. Subsequently, their older sibling acted as a confederate and tried to persuade them to change their decisions. RESULTS: After the appeals of older siblings, younger children significantly shifted their decisions: choices of less risky paths replaced the initial selection of more risky paths, and vice versa. A positive sibling relationship was predictive of younger siblings' decision changes. Boys and girls were equally effective in persuasion but they did so using different types of arguments, with boys communicating primarily appeals to fun and girls emphasizing appeals to safety. CONCLUSIONS: These findings highlight the effect that older siblings can have on risk taking decisions of younger siblings. Accordingly, they document the importance of considering the interpersonal context of risk taking when designing interventions to reduce injuries among elementary schoolchildren.

Effects of sound frequency on behavioral and cardiac orienting in newborn and five-month-old infants.

Alert newborn and 5-month-old infants' responsivity to variations in spectral composition of a rattle sound was examined. Each child received four stimulus conditions: low-, mid-, and high-frequency bandpass-filtered rattles and an unfiltered broadband rattle. Stimuli were played through a single loudspeaker laterally positioned, and head orientation and cardiac responses to sound were recorded. Compared to other stimuli, the low-frequency sound elicited less head turning in both age groups, with this effect exaggerated in younger infants. Head orientation toward the mid-frequency, high-frequency, and broadband stimuli did not differ with age. For all conditions, latency and duration of newborns' head turning was longer than that of 5-month-olds. Newborns responded with cardiac deceleration only on trials when they failed to turn. When head turns occurred, an acceleratory cardiac response was obtained. Five-month-olds responded with reliable cardiac deceleration irrespective of head turning toward the sound. Heart rate change did not vary as a function of frequency at either age, suggesting that all stimuli were equally effective in eliciting the infant's attention.

Infants' localization of sounds within hemifields: estimates of minimum audible angle.

Infants' acuity in localizing sounds within hemifields was examined by determining the smallest sound shift off 60 degrees and along the horizontal axis that infants could discriminate reliably, that is, minimum audible angle (MAA). Infants 6, 12, and 18 months of age were tested using a Go/No-Go conditioned head-turn procedure in which infants received an equal number of no-change (control) trials and sound-shift (experimental) trials. A correct response (i.e., a head turn toward the loud-speakers) on an experimental trial resulted in visual reinforcement. Localization acuity for sounds within hemifields was fairly poor and improved systematically with increasing age. MAA estimates at each age were significantly higher, indicating poorer localization acuity, in comparison to those obtained previously in research examining infants' resolution of auditory space near midline. These findings are consistent with adult data and demonstrate a finer partitioning of auditory space near midline than within hemifields. The implications of these findings for our understanding of the development of auditory processing mechanisms in sound localization are discussed.