Postnatal depression mediates the relationship between infant and maternal sleep disruption and family dysfunction

BACKGROUND

Previous research has linked family sleep disruption and dysfunction in children; however, the mechanism is unknown.

AIMS

This study examined whether maternal sleep and postnatal depression (PND) mediate the relationship between infant sleep disruption and family dysfunction.

STUDY DESIGN AND PARTICIPANTS

Mothers of infants aged 12 months old (N=111; 48% male) completed infant and parent sleep surveys, the Edinburgh Postnatal Depression Scale and the Family Assessment Device.

RESULTS

Poor infant sleep was related to poor maternal sleep, which was associated with higher PND and higher level of family dysfunction.

CONCLUSIONS

Results are consistent with the proposition that identification of both infant and maternal sleep problems during infancy can be relevant to reduction of PND and improved family functioning.

Family quality of life of Australian families with a member with an intellectual/developmental disability

BACKGROUND

Family quality of life (FQOL) is a recent concept in intellectual/developmental disability research. Outcomes for the family are important to the provision of services because families, rather than institutions, are increasingly considered the primary support unit. This article presents Australian findings using the international Family Quality of Life Survey: Main Caregivers of People with Intellectual or Developmental Disabilities (FQOLS-2006).

METHOD

Forty-two South Australian main caregivers of people with an intellectual/developmental disability were interviewed using the FQOLS-2006. The FQOL domains assessed were Health of the Family, Financial Well-being, Family Relationships, Support from Other People, Support from Disability-Related Services, Influence of Values, Careers, Leisure and Recreation, and Community Interaction. Domains were measured in terms of Importance, Opportunities, Attainment, Initiative, Stability and Satisfaction. The FQOLS-2006 asked about the family's practical and emotional Support from Other People together, whereas the current study separated the constructs of practical and emotional support. Questions pertaining to FQOL in the past were also added, in order to gain a broader picture of present FQOL.

RESULTS

Results indicated that families considered all the FQOL domains to be important. However, Health, Family Relationships and Financial Well-being were regarded as slightly more important than Practical and Emotional Support from Others. The attainment of Family Relationships, Health, Values, and Leisure and Recreation were rated as quite a bit, but Practical Support from Other People was only rated as a little. Families were generally satisfied with all FQOL domains, but they were satisfied with their Family Relationships and they were neither satisfied or dissatisfied with their Financial Well-being. Results also indicated that there was a need to distinguish between the provision of practical and emotional support from others, because the attainment of emotional support was rated at a slightly higher level than practical support.

CONCLUSIONS

The FQOLS-2006 provided a comprehensive measure of FQOL, which, with some additional modifications, could be used to better inform service provisions and ultimately enhance the quality of life of people with intellectual/developmental disabilities and their families.

The string measure of the ERP: what does it measure?

The event-related brain potential (ERP) has been investigated extensively inan effort to understand the neurophysiological bases of intelligence. Measures derived from the ERP have been used as indices of intelligence, particularly the string measure of the complexity of the ERP. However, the string measure has been criticised for being non-specific and for being dependent on ERP amplitude. These criticisms were tested by investigating relationships between ERP string measure, ERP amplitude measures, and the ERP power spectrum. It was found that the string measure was non-specific in that it indexes both low and high frequency event-related activity; the string measure is also dependent on ERP amplitude. The string measure is therefore not a valid measure of the ERP. It was concluded that the string measure should be abandoned; human intelligence cannot map in a simple way onto gross measures of scalp-recorded electrocortical activity.

Uncoupling learning from initial recall: the relationship between speed and memory deficits in old age

Nettelbeck & Rabbitt (1992) found that measures of speed of performance with low knowledge requirements (four-choice reaction time, inspection time and coding-substitution) accounted substantially for age-related changes among 104 persons aged from 54 to 85 years in a number of more complex cognitive measures reflecting general fluid ability. However, the numbers of words recalled from a list after either a single brief viewing of each word, or following a cumulative learning procedure across four trials, provided an exception to this general trend, leading to the conclusion that some aspects of memory may be independent of mental speed. A follow-up of 82 of the same people 18-20 months later was designed to partition performance in a similar cumulative learning procedure into an initial first recall component and a subsequent learning component. This was accomplished by fitting individual cumulative learning data with a hyperbolic power function which met the theoretical requirement of defining separate initial recall and learning parameters. These parameters were found to be independent and it was concluded that learning involved rehearsal, whereas first recall did not. The hyperbolic power function provided a good account for 92 per cent of individual cases. Analyses which combined Nettelbeck & Rabbitt's (1992) data with new measures confirmed the reliability of these authors' results. Furthermore, it was found that first recall, but not learning, was mediated by processing speed. Learning was relatively unaffected by age-related slowing in mental speed, suggesting that Nettelbeck & Rabbitt's results were the consequence of a strong rehearsal component in their memory tasks. Thus, while mental slowing is clearly one important aspect of cognitive decline during old age, it does not constitute a sufficient explanation for changes in all areas of cognitive functioning. Specifically, age-decline in rate of learning with rehearsal appeared to be independent of slowing in speed of information processing.

Vulnerability to criminal exploitation: influence of interpersonal competence differences among people with mental retardation

A study by Wilson & Brewer (1992) has indicated that people with mental retardation are at greater risk of having a crime committed against them than age-matched cohorts from the general population. The present study was designed to test the hypothesis that this heightened vulnerability is partially explained in terms of behavioural shortcomings reflecting interpersonal competence. Twenty victims of crime and 20 nonvictims, all with mental retardation, were recruited so that means for age, adaptive behaviour and IQ were similar. Groups were compared on the Test of Interpersonal Competence and Personal Vulnerability (TICPV) developed for the present study. Results showed poorer interpersonal competence among the victims, indicating that victims had difficulty in deciding on the appropriate behaviour in some interactions. Performance on the test was shown to be internally consistent, stable over time and a valid measure of vulnerability. The study concluded with recommendations for more detailed investigation of the precise behaviours which influence risk as a first step in an attempt at remediation.

Psychological outcome of ECMO-eligible neonates with severe respiratory failure treated using conventional medical therapy

OBJECTIVE

The present study addressed a National Health and Medical Research Council (NHMRC) recommendation that the outcome of neonates who are treated conventionally for respiratory problems be further investigated before setting up additional extracorporeal membrane oxygenation (ECMO) centres in Australia.

METHODOLOGY

The cognitive and behavioural outcome of ECMO eligible infants who received conventional treatment for respiratory problems at birth was assessed in 18 infants aged 1.5-3 years (index group). ECMO was not available at either of the treating hospitals. Index children were compared to a matched control group of children who did not experience any major complications at birth. Children were assessed using either the Bayley or McCarthy scales of infant development and the Child Behavior Checklist.

RESULTS

Overall, a mortality rate of 19% and a psychological morbidity rate of 18% suggest that children born with severe respiratory failure, who meet existing ECMO eligibility criteria, have a good prognosis when treated using conventional medical therapy.

CONCLUSIONS

Improvements to conventional treatments indicate that ECMO eligibility criteria may need to be revised to identify accurately those infants who are at extreme risk of mortality if treated conventionally.

The abilities of a musical savant and his family

The ability of a male autistic savant (TR) to play two unfamiliar piano pieces after listening to a tape-recording was tested, closely following the procedures of Sloboda, Hermelin, and O'Connor (1985). Other components of TR's musical ability--pitch recognition, improvisation, and ability to provide harmonic accompaniment--were also examined. TR's musical precocity was examined in relation to his general level of intellectual functioning as indexed by a battery of standardized psychological tests of intelligence, memory, reading, visual organization, and creativity. His parents and two male siblings also completed tests of intelligence. Results from psychometric testing indicated that TR has idiosyncratic levels of cognitive functioning with difficulties in verbal reasoning but high levels of concentration and memory. His speed of information processing, as indicated by Inspection Time, and was better than average. TR demonstrated perfect pitch recognition and other family members also demonstrated excellent relative pitch. TR's ability to recall and perform structured music within both the diatonic and whole-tone systems was exceptional but dependent upon his familiarity with musical structure and was therefore organized and rule-driven. Furthermore, TR demonstrated competence in improvisation and composition, albeit restricted by his adherence to structural representations of familiar musical rules.

The "intelligence" of calendrical calculators

Strategies of 4 men (WAIS-R range 65 to 76) when making calendar calculations were investigated. Each subject completed a battery of standardized psychological tests. Results suggested that subjects were aware of rules and regularities associated with the calendar, including knowledge of the 14 different calendar templates, one of which describes any calendar year. Their strategies were rigidly applied and could not be modified easily, even when doing so would have facilitated performance. The involvement of practice, memory, anchor dates, eidetic imagery, and mathematical algorithms were discussed. We concluded that these savants relied heavily on memory, with little manipulation of cognitive input, as opposed to transforming stimuli.

Inspection time as mental speed in mildly mentally retarded adults: analysis of eye gaze, eye movement, and orientation

The effect of eye movements away from a target on accuracy of visual discrimination was examined. In Experiment I inspection time was measured for 10 mildly mentally retarded and 10 nonretarded adults under two conditions, with each trial initiated by the subject or under experimental control. Retarded subjects did not gain any advantage from controlling trial onset. Video records of eye movements revealed that retarded subjects glanced off-target more than did nonretarded controls, but this was not sufficient to explain appreciably slower inspection time of the retarded group. Experiment 2 supported this conclusion; the same subjects completed a letter-discrimination task with direction of gaze monitored automatically. Although retarded subjects' eye gaze was more scattered early during a trial, gaze was appropriately directed by the time that the target appeared. Results from both experiments supported the hypothesis that speed of central, perceptual processing is slower among retarded persons, over and above the influence of distractibility. Results from three experiments in Part II were consistent with this interpretation. Experiment 3 was designed to eradicate trials among retarded subjects in which gaze was not properly directed, but results showed that too few such events occurred to influence accuracy. Experiment 4 demonstrated that the preparatory procedure in the previous studies resulted in efficient eye gaze among retarded subjects. Experiment 5 confirmed that lower discriminative accuracy among 10 retarded adults (compared with 10 nonretarded controls) was not due to less-efficient orientation prior to discrimination.

A cross-sequential analysis of developmental differences in speed of visual information processing

Development of processing speed was examined in three backward masking studies. The first verified the central nature of backward masking for children aged 8 and 11 years and for adults. The second suggested that task requirements were equivalent for children similar to those in Study 1, and that age differences in performance were not attributable to nonprocessing variables. The main cross-sequential study estimated speed of processing in 80 children (approximately 6 years to 13 years) and young adults using an inspection time task. Target exposure duration was varied to establish the time required to achieve a high level of discriminative accuracy. Estimates of processing speed increased until about 11-13 years of age; beyond this, the trend was less obvious, and it is possible that inspection time asymptotes at around the onset of adolescence. Performance improvement after 1 year could not be explained as resulting from practice since improvement among controls over a period of 2 weeks was significantly less. Correlations between estimates of inspection time made up to 2 years apart found the measure to be reliable.

Mental retardation and inspection time: a two-stage model for sensory registration and central processing

Mildly mentally retarded and nonretarded young adults were compared in simple visual discrimination tasks from which can be derived an estimate of inspection time (lambda), assumed to reflect the time taken by some basic component in the decision process. In the first experiment retarded and nonretarded subjects' performance showed improvement in a condition employing a backward mask to limit the duration of sensory information available to subsequent central processes, but substantial group differences in lambda remain unchanged. When target stimuli were presented for short durations, but without interruption by masking, retarded subjects performed less effectively than did nonretarded subjects and, despite extensive practice, did not achieve nonretarded subjects' levels. These results suggested a two-stage serial model of discrimination that was tested in the second experiment. Concurrent manipulation of two factors confirmed that (a) lambda involves initial sensory registration followed by central processing, (b) for both groups these stages are independent, and (c) poorer performance among retarded subjects is the consequence of deficiencies at both stages.

Mental retardation, inspection time, and central attentional impairment

Performance of mentally retarded and nonretarded adults on simple visual discrimination tasks was compared. Experiment 1 involved a lines-discrimination task used in previous research to measure inspection time. A dichoptic stimulus presentation procedure was employed, with target and masking stimuli presented to different eyes so that only central masking could occur. Experiment 2 involved a discrimination between two lights in different positions, demonstrating that masking was characterized by constant stimulus-onset-asynchrony, because the relationship between target duration and the interval between target offset and mask onset was additive. Results from both experiments confirmed that for both retarded and nonretarded subjects, the backward masking procedures used interfered with visual processing at a central level. In Experiment 3 markedly deviant smooth pursuit eye movements in a pendulum tracking task occurred among retarded subjects but not among nonretarded subjects. This deviancy was additional to other indications of poor attention. In the retarded group the correlation between estimates of inspection time and deviant eye tracking was .64, but other instances of inattentiveness were not related to either of these two measures. This finding was interpreted in terms of an involuntary dysfunction within some central attentional system that involves at least three qualitatively different levels.

Effects of procedure on memory scanning of mildly mentally retarded adults

The performance of mildly mentally retarded adults on recognition memory tasks was compared with that of nonretarded control subjects. Following Sternberg's (1969) procedure, material to be remembered was presented in a fixed-set procedure, during which subjects were tested repeatedly on the same well-learned set of material, and a varied-set procedure, during which they were only tested on a memory set once before having to learn a new set. Mean reaction times (RTs) in all groups increased linearly as the number of items in the fixed memorized set increased; but "no" RTs of retarded adults tested under the varied-set procedure did not show this pattern. There was a gradation of slopes for the linear regression functions of RT on memory set size in both procedures, from less steep for nonretarded adults to increasingly steep values for nonretarded children and retarded adults. These results suggest that retarded adults use different processing strategies in the two procedures and that rate of processing increases with increasing mental age.

Effects of practice on recognition memory of mildly mentally retarded adults

The effect of practice on recognition memory of mildly mentally retarded adults was investigated in two experiments using the Sternberg (1969) memory scanning paradigm. In Experiment 1, the slope and zero intercept for item-recognition functions under both fixed- and varied-set procedures decreased over seven sessions of practice among retarded adults and nonretarded children, remaining relatively constant among nonretarded adults. Because performance of only retarded subjects had not yet reached asymptote, Experiment 2 provided these subjects with additional practice at the same task (varied-set procedure only). After extended practice, slopes in the retarded group were near those for both nonretarded groups; therefore, although the generally poorer performance of retarded adults in this task may reflect some structural impairment, the initial level of deficiency is reduced by practice.

Adaptive behavior of mentally retarded adults in work-preparation settings

Mentally retarded adult trainees (N = 370) at work preparation centers were rated by their supervisors on the AAMD Adaptive Behavior Scale (ABS). Results confirmed the reliability and criterion validity of the ABS, demonstrating its sensitivity to differences in adaptive and maladaptive behavior between subgroups representing variation in seven personal variables: age, sex, estimated intellectual ability, etiology, place of living, the presence or absence of any mobility handicap, and use of medications. Results were compared with those from a study of retarded adolescents attending school (Salagaras & Nettelbeck, 1983). On the average, trainees had a higher adaptive behavior profile than did students, but no significant differences were found in maladaptive behavior. The ABS measures indicated that about 75% of students were behaviorally prepared to make the transition to work preparation centers.

Adaptive behavior of mentally retarded adolescents attending school

Teachers rated 550 mentally retarded adolescents attending special schools on the AAMD Adaptive Behavior Scale (ABS). Results established the reliability and criterion validity of the ABS for use among school-age students and demonstrated the sensitivity of the scale to variation in adaptive and maladaptive behavior between subgroups of mentally retarded students representing differences in seven personal variables: age, sex, estimated intellectual ability, etiology, place of living, the presence or absence of any mobility handicap, and use of medications.

Locating information-processing deficits of mildly mentally retarded young adults

When 2 nonoperative lights were added to each of the ends of a stimulus display in a 4-choice reaction time (RT) task, the RTs of mentally retarded and nonretarded subjects were slowed to about the same extent. When 2 nonoperative keys were added to each of the ends of the response display, retarded subjects' RTs were slowed more than those of the nonretarded subjects. The combined effects of the conditions involving nonoperative lights and keys were not found to be additive for either group of subjects, suggesting that, separately, each condition resulted in an increase in stimulus-response incompatibility in addition to an increase in the difficulty of stimulus identification or response selection.

Effects of practice on inspection time for mildly mentally retarded and nonretarded adults

Successive estimates of inspection time (lambda) interspersed with practice were made for 10 mildly retarded adults (mean IQ = 60) and 10 nonretarded adults. Each subject completed approximately 800 trials overall. A significant practice effect was found for both groups, but with average measures of lambda from the retarded group remaining more than twice as long as those from the nonretarded group. Intercorrelations within both groups between measures confirmed that lambda provides a reliable index of discriminative performance. A response requirement involving a keypress was compared with a simplified pointing response, but results indicated that these alternatives did not influence estimates of lambda on the effects of practice.

Inspection time: an index for intelligence?

Recent publicity has been given to reports of high correlations between IQ and “inspection time”, a measure derived from simple discrimination which is assumed to provide an estimate of the time taken by a basic component of the decision process. However, this publicity has not recognised that the inclusion of mentally retarded participants in the experiments concerned may have led to inflated correlations, because of the marked extent to which the performance of retarded subjects is inferior to that of nonretarded subjects. Evidence from the performance of nonretarded subjects in three studies suggests that although speed of decision is related to IQ, the degree of association is smaller than recent publicity has suggested. Inspection time does not appear at present to hold promise as an index from which a “culture-fair” measure of intelligence might be derived.

Medication and reinforcement within a token programme for disturbed mentally retarded residents

The interaction between psychotrophic medication and a token programme as treatment modalities for mentally retarded individuals with behavioural problems was investigated in two studies. In the first, involving four residents, the dependent variables were credits earned and lost each day for performing specified behaviours within the token programme. Each subject was given a major tranquillizer in alternate months over a four month period. There was a noncontingent token phase prior to, and after completion of, the experimental phases. All subjects showed an immediate increase in the level of appropriate behaviour with the introduction of the token economy, and continuing improvements thereafter. Medication did not have a significant effect on the rate of appropriate or inappropriate behaviour. The second study assessed the relative efficacy of token reinforcement and medication in controlling behaviour symptomatic of psychosis in a resident at school and during meal-times in the ward. Five behaviours recorded were swearing, inappropriate laughter, facial grimaces, fighting, and out-of-seat. Following baseline measures, the absence of facial grimaces was reinforced in the school but not in the word. The contingencies were then reversed. A major tranquillizer was then administered, together with a replication of the first two conditions. The use of tokens to control facial grimaces resulted in the concurrent suppression of the four other symptoms. There weas no remission of any symptom as a consequence of medication alone.

Influence of procedural variables on estimates of inspection time for mildly mentally retarded adults

Two groups of 8 young adults (mean IQ = 68), matched on the basis of age and initial estimates of inspection time (lambda), were compared under conditions in which subjects were instructed either to respond as quickly and accurately as possible or to respond accurately and were praised each time that a response was slower than their mean reaction time (RT) during the initial session. Praise slower RT appreciably but did not affect accuracy, so that second measures of lambda were similar to initial estimates. In a second experiment lambda was measured for 8 retarded (mean IQ = 69) and 8 nonretarded adults under conditions in which stimulus-exposure durations either varied randomly or were arranged in regular blocks from long to short durations. Estimates were significantly longer among retarded subjects and were not influenced by procedure. Reaction times were not affected by procedure, being faster on the average for retarded subjects and relatively constant irrespective of exposure duration, whereas for nonretarded subjects RT increased as exposure duration decreased. Despite the resilience of lambda to procedural variation, differences in RT among retarded and nonretarded samples raise questions about which processes lambda is measuring.

Cognitive rigidity in the aged and the mentally retarded

Three groups, one of elderly, one of young mentally retarded, and one of non-retarded young persons were compared on a visual recognition task which involved changing from one category of identification to another. The mentally retarded participants had greater difficulty in changing categories than did the non-retarded participants. Results for the elderly were similar but may have been partly due to the choice of stimulus material. In a second task, the same elderly and non-retarded young participants named as many objects as possible in one minute. The elderly group produced fewer responses on average than the young group and fewer categories of such responses. Results suggested that older persons find it more difficult to change between different categories of identification.

Vigilance of performance of mildly mentally retarded children

The contribution of developmental factors to the vigilance performance of mildly mentally retarded children was investigated by comparing their vigilance performance with that of nonretarded children of the same CA and with younger nonretarded children of about the same MA. The retarded children showed an earlier and faster decline in vigilance performance than did the CA control group. This result was similar to that of Semmel (1965), but contrasted with that of Kirby, Nettlebeck, and Bullock (1978), who found no such difference in vigilance performance when comparing mildly mentally retarded and nonretarded adults. The MA control group performed in a similar way to the retarded children, suggesting that the more rapid decline in vigilance performance was largely a developmental phenomenon.

Discrimination, translation, or response organization: a clarification of factors underlying slower responding among mentally retarded persons

Apparently contradictory findings regarding the locus of information-processing differences between retarded and nonretarded persons were discussed. We suggested that these apparent contradictions may be due to differences in the relative involvement of central processes associated with perception, stimulus--response translation, and response programming in the experimental tasks that have been used in this type of research.

Speed and accuracy in the choice reaction time of mildly retarded adults

Reaction times (RTs) to inside stimuli in an 8-choice task decreased for some retarded subjects when the response ensemble was concealed. Corresponding increases in errors suggested that these subjects made separate visual checks of the response keys in order to respond accurately. Other retarded subjects maintained accurate performance by taking longer to respond. An examination of error data from a number of RT experiments indicated that retarded subjects made more errors than did nonretarded subjects when stimuli and responses were less descriminable. A comparison of RTs for correct and incorrect responses reflected intermittent rather than general tendencies to sacrifice accuracy for speed, a result consistent with the possibility of occasional attentional lapses.

Age, intelligence, and inspection time

Ten young males whose IQ scores ranged from 51 to 71 were compared on a simple discrimination task with 10 male university students of the same CA and 28 nonrelated male children. Estimates of inspection time (lambda) were obtained from the pattern of errors made by each subject; lambda is assumed to reflect the rate at which sensory input is accumulated and processed. Average estimates of lambda from four groups of children (7, 8, 9, and 10 years) were 147, 142, 137, and 139 msec, respectively. The mean for university students was 130 msec, whereas that for retarded adults was 256 msec. Mean reaction time (RT) of all nonretarded groups increased as stimulus-exposure duration decreased, children being slower than adults. Retarded subjects' RT was less influenced by stimulus-exposure duration and was faster than that of nonretarded groups at the shortest exposure. These results suggest that slower perceptual speed among retarded persons is a consequence of a permanent deficiency; differences in response strategy may explain the differences in RT.

Vigilance performance of mildly mentally retarded adults

Mildly mentally retarded adults were compared on both an auditory and a visual vigilance task with subjects having greater than average intelligence. Contrary to results reported by Semmel (1965) using a visual task, no difference was found in the rate of decline of performance between the two groups in either of the two tasks, although overall performance of the above-average group was superior to that of the retarded group. The results offered no support for the hypothesis that mentally retarded persons suffer from a more rapid decay in arousal under conditions of reduced sensory variation. Nor did they support a suggestion that in this particular situation retarded subjects would demonstrate more inattention than would nonretarded subjects.

Intelligence, reaction time, and inspection time

Forty-eight subjects with IQ scores ranging from 57 to 138 discriminated between two lines of markedly different length, exposed for varying periods of time. Estimates of inspection time, lambda, a measure assumed to reflect the rate at which sensory input is processed, were obtained from the pattern of errors made by each subject and, therefore, independently from the reaction time (RT) required to respond. lambda correlated negatively with IQ scores. RTs of nonretarded subjects increased as stimulus-exposure duration decreased, whereas for retarded subjects RTs remained constant. This is interpreted as indicating differences between the groups in response strategy under conditions of difficult discrimination. The rate of information processing was also estimated in a different choice RT situation, using as an index the reciprocal of the slope of the function relating RT to degree of stimulus choice. Retarded subjects had slower rates and longer RTs than nonretarded subjects. A second experiment controlling for response-selection factors confirmed that this slowness could not be attributed to gross-movement difficulties and that a slower rate of information transmission seemed to be involved.