ORCID Profile
0000-0001-7265-6242
Current Organisation
University of Adelaide
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Publisher: Elsevier BV
Date: 06-2015
DOI: 10.1016/J.BANDL.2015.04.004
Abstract: The developmental trajectory of language lateralisation over the preschool years is unclear. We explored the relationship between lateralisation of cerebral blood flow velocity response to object naming and cognitive performance in children aged 1-5 years. Functional transcranial Doppler ultrasound was used to record blood flow velocity bilaterally from middle cerebral arteries during a naming task in 58 children (59% male). At group level, the Lateralisation Index (LI) revealed a greater relative increase in cerebral blood flow velocity within the left as compared to right middle cerebral artery. After controlling for maternal IQ, left-lateralised children displayed lower expressive language scores compared to right- and bi-lateralised children, and reduced variability in LI. Supporting this, greater variability in lateralised response, rather than mean response, was indicative of greater expressive language ability. Findings suggest that a delayed establishment of language specialisation is associated with better language ability in the preschool years.
Publisher: Elsevier BV
Date: 07-2014
DOI: 10.1016/J.BANDC.2014.05.001
Abstract: We aimed to investigate the contributions of visual letter form and abstract letter identity to the time course of letter recognition, by manipulating the typeface (i.e. font) in which letters were presented. Twenty-six adult participants completed a modified one-back task, where letters where presented in easy-to-read typefaces ("fluent" letter stimuli) or difficult-to-read typefaces ("disfluent" letter stimuli). Task instructions necessitated that participant's focus on letter identity not visual letter form. Electroencephalography was collected and event-related potentials (ERPs) were calculated relative to letter stimuli. It was found that typeface affected both early-mid (N1 litude and P2-N2 litude and latency) and late processing (450-600ms), thereby including time points whereby it is theorised that abstract identity is extracted from visual letter form (that is, 300ms post-stimulus). Visual features of the letter therefore affect its processing well beyond the currently theorised point at which abstract information is extracted which could be explained by a feedback loop between abstract letter representations and lower-level visual form processing units, which is not included in current cognitive reading models.
Publisher: Oxford University Press (OUP)
Date: 08-2014
DOI: 10.5665/SLEEP.3930
Publisher: IEEE
Date: 08-2012
Publisher: IEEE
Date: 03-2022
Publisher: Wiley
Date: 11-02-2013
DOI: 10.1111/JSR.12036
Abstract: Upper airway obstruction during adulthood is associated with cardiovascular morbidity cardiovascular consequences of childhood upper airway obstruction are less well established. This study aimed at investigating the effect of childhood upper airway obstruction on respiratory sinus arrhythmia as a measure of cardiac vagal modulation during night-time sleep. Overnight polysomnography was conducted in 40 healthy children (20 M age: 7.5 ± 2.6 years body mass index percentile: 60.7 ± 26.4%) and 40 children with upper airway obstruction (24 M age: 7.5 ± 2.7 years body mass index percentile: 65.8 ± 31.9%). We used the phase-averaging technique to compute respiratory sinus arrhythmia litude and phase delay. To study sleep stage effects and the effect of upper airway obstruction, respiratory sinus arrhythmia was measured during all artefact-free sleep episodes, and after exclusion of respiratory events. A significant increase in respiratory sinus arrhythmia litude and phase delay was observed during stage 4 sleep as compared with rapid eye movement sleep in both groups ( litude: controls = 0.10 ± 0.03 versus 0.07 ± 0.02 s, P < 0.01, respectively, and upper airway obstruction = 0.07 ± 0.03 versus 0.05 ± 0.03 s, P < 0.05, respectively phase delay: controls = 3.1 ± 0.1 versus 3.0 ± 0.1 rad, P < 0.05, respectively, and upper airway obstruction = 3.13 ± 0.04 versus 3.04 ± 0.08 rad, P < 0.01, respectively). A significant association between respiratory sinus arrhythmia and apnea/hypopnea index was observed during stage 2 sleep in children with upper airway obstruction. Compared with healthy controls, a significant decrease in respiratory sinus arrhythmia litude during stage 2 sleep was observed in children with upper airway obstruction (0.09 ± 0.03 versus 0.06 ± 0.03 s, P < 0.05). However, this difference was not apparent when respiratory events were excluded from analysis. Importantly, respiratory sinus arrhythmia showed a strong negative correlation with body mass index. In conclusion, night-time respiratory sinus arrhythmia in children is sleep stage dependent and normal during quiet sleep in children with relatively mild upper airway obstruction.
Publisher: Wiley
Date: 28-12-2010
DOI: 10.1111/J.1365-2869.2009.00798.X
Abstract: Arousal from sleep is associated with transient and abrupt cardiorespiratory changes, and elevated arousals associated with sleep disorders may trigger adverse cardiovascular sequela. In this paper, we provide the first data in children on cardiorespiratory responses to cortical arousal. Heart rate and ventilatory responses to arousal from stage 2 and rapid eye movement (REM) sleep were investigated in 40 normal, healthy Caucasian children (age: 7.7 +/- 2.6 years body mass index z-score: 0.30 +/- 0.8). All children underwent overnight polysomnography studies. Cortical arousals were scored according to standard criteria. Heart rate changes were assessed over 30 s, starting 15 s prior to cortical arousal onset. Breathing rates were quantified three breaths before and after arousal onset. Arousals from stage 2 as well as REM sleep resulted in an R-R interval shortening of about 15%, independent of age and gender. The R-R interval shortening initiated at least 3 s before the cortical arousal onset. The breathing interval immediately after cortical arousal onset was significantly shortened (P < 0.001). In conclusion, cortical arousals in children are associated with an increase in breathing rate and significant heart rate accelerations, which typically precede the cortical arousal onset.
Publisher: Elsevier BV
Date: 11-2020
Publisher: MDPI AG
Date: 06-07-2020
DOI: 10.3390/MTI4030037
Abstract: Three-dimensional rendering technologies have long been utilized for explanatory purposes in scientific visualization and related areas. Their applications to wider fields, however, have often been limited. In this paper, we explore the use of 3D model and animation techniques, combined with narrative techniques, for recreating event-based information to aid understanding. An empirical experiment was conducted which examined the effectiveness of 3D model images and 3D animation videos compared to reading narratives in textual form. The results indicated that both forms of 3D graphical techniques positively supported users in terms of cognitive load, recall, and engagement over reading text.
Publisher: Springer Science and Business Media LLC
Date: 07-2013
DOI: 10.1007/S11325-012-0736-9
Abstract: Problematic behavior is widely reported in children with sleep-disordered breathing (SDB). Daytime behavior is an important component in the evaluation of clinical history in SDB however, there is a reliance on parental report alone, and it is unclear whether reports by teachers will aid diagnosis. We assessed sleep and behavior reported by both parents and teachers in 19 children with SDB and 27 non-snoring controls. All children were screened for prior diagnoses of other medical and/or behavior and learning disorders and underwent polysomnography and both parental and teacher assessment of behavior. Both parents and teachers report greater problematic behavior in SDB children, predominantly of an internalizing nature. Despite this consistency and moderate correlation between informants, the agreement between parent and teacher reports of in idual child behavior was poor when assessed using Bland-Altman plots. Clinicians should be mindful that the behavioral history of a child being evaluated for SDB may vary depending on whether parent or teacher report is being discussed as this may influence clinical decision making.
Publisher: Cold Spring Harbor Laboratory
Date: 11-11-2017
DOI: 10.1101/218123
Abstract: We hypothesise a beneficial influence of sleep on the consolidation of the combinatorial mechanisms underlying incremental sentence comprehension. These predictions are grounded in recent work examining the effect of sleep on the consolidation of linguistic information, which demonstrate that sleep-dependent neurophysiological activity consolidates the meaning of novel words and simple grammatical rules. However, the sleep-dependent consolidation of sentence-level combinatorics has not been studied to date. Here, we propose that dissociable aspects of sleep neurophysiology consolidate two different types of combinatory mechanisms in human language: sequence-based (order-sensitive) and dependency-based (order-insensitive) combinatorics. The distinction between the two types of combinatorics is motivated both by cross-linguistic considerations and the neurobiological underpinnings of human language. Unifying this perspective with principles of sleep-dependent memory consolidation, we posit that a function of sleep is to optimise the consolidation of sequence-based knowledge (the when ) and the establishment of semantic schemas of unordered items (the what ) that underpin cross-linguistic variations in sentence comprehension. This hypothesis builds on the proposal that sleep is involved in the construction of predictive codes, a unified principle of brain function that supports incremental sentence comprehension. Finally, we discuss neurophysiological measures (EEG/MEG) that could be used to test these claims, such as the quantification of neuronal oscillations, which reflect basic mechanisms of information processing in the brain.
Publisher: Oxford University Press (OUP)
Date: 12-2014
DOI: 10.5665/SLEEP.4264
Publisher: Informa UK Limited
Date: 06-03-2018
Publisher: IEEE
Date: 07-2013
Publisher: Elsevier BV
Date: 12-2011
DOI: 10.1016/J.SLEEP.2011.03.023
Abstract: This study aimed to assess the influence of snoring and sleep duration on developmental outcomes in 6 month old infants. As part of a longitudinal study of snoring in infancy, we identified 16 children (13 males) who commenced snoring shortly after birth and continued to snore frequently (≥ 3 nights/week) at 6 months of age and 88 healthy infant controls who were reported never to snore in the absence of a cold (36 males). Infants were assessed at 6 months of age with the Bayley Scales of Infant and Toddler Development Edition III, and parents completed demographic, sleep, and developmental surveys. Cognitive development was reduced in infants who snored frequently (mean=95.3 SD=4.3) from the first month of life compared to control infants (mean=100.6 SD=3.9) (F [1, 99]=23.8, p<.01 η(p)(2)=.21). Snoring during the first 6 months of life was associated with lower cognitive development scores. It is unknown whether these infants will continue to snore through childhood and, if so, whether the associated neurocognitive deficits will become worse with time.
Publisher: Oxford University Press (OUP)
Date: 05-2012
DOI: 10.5665/SLEEP.1824
Publisher: MDPI AG
Date: 04-08-2016
DOI: 10.3390/NU8080479
Publisher: American Thoracic Society
Date: 15-11-2014
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2020
Publisher: Elsevier BV
Date: 02-2018
DOI: 10.1016/J.SMRV.2017.01.005
Abstract: Medications that trigger sleepwalking may inadvertently put the patient at risk of injury to themselves and/or others, and contribute to poor treatment adherence. The aim of this study was to systematically review the literature to identify drugs that may increase the risk of sleepwalking. A search of CINAHL, EMBASE, PsycINFO, PubMed, and ScienceDirect was conducted with the keywords 'sleepwalking' OR 'somnambulism'. Of the original 83 sourced papers, 62 met the inclusion criteria and were subsequently included for review. Twenty-nine drugs, primarily in four classes-benzodiazepine receptor agonists and other gamma aminobutyric acid (GABA) modulators, antidepressants and other serotonergic agents, antipsychotics, and β-blockers-were identified as possible triggers for sleepwalking. The strongest evidence for medication-induced sleepwalking was for zolpidem and sodium oxybate. All other associations were based on case reports. This research highlights the importance of considering sleepwalking in risk profiles in clinical trials, particularly for drugs that enhance GABA activity at the GABA
Publisher: Informa UK Limited
Date: 27-02-2014
Publisher: Elsevier BV
Date: 02-2022
DOI: 10.1016/J.JECP.2021.105308
Abstract: Sleep is important for emotional well-being, memory, and development in children. Regarding memory, sleep has been shown to advantage accuracy for declarative tasks but not procedural tasks. There is some evidence to suggest that sleep provides a relatively greater benefit for memory of negative emotional versus neutral images. However, the extent to which sleep benefits emotionally positive memories in children is not clear. This study assessed memory after nocturnal sleep versus daytime wake in a within-person design involving a s le of 40 children aged 7 to 14 years (M = 10.6 ± 1.9 years 18 boys and 22 girls) for images of negative, neutral, and positive valences. Results show that after accounting for response time, memory accuracy overall was greater after sleep compared with equivalent time of wake and memory accuracy was greatest for positive images compared with both negative and neutral images. However, there was no difference between memory for negative images and that for neutral images in children, and there was no condition by valence interaction. Sleep characteristics as recorded using actigraphy, diary, and parent report were not predictive of memory performance after sleep when correcting for multiple comparisons. Overall, the results suggest that sleep may benefit memory in otherwise healthy children but that despite a bias toward memory for positive items over both negative and neutral items, there is not a relatively greater benefit for emotional versus neutral memory consolidation across sleep periods compared with wake periods.
Publisher: Elsevier BV
Date: 12-2011
DOI: 10.1016/J.SLEEP.2011.07.006
Abstract: The aim of the present study was to evaluate the effect of persistent snoring in the first year of life on developmental outcomes. As part of a longitudinal study of snoring and sleep in infancy, we identified 13 children (10 males) who commenced snoring shortly after birth and continued to snore frequently (≥ 3 nights/week) at 6 and 12 months of age and 78 controls (31 males) who were reported by parents to never snore in the absence of a cold. Infants were assessed with the Bayley Scales of Infant and Toddler Development Edition III and parents completed demographic and sleep questionnaires. Infants reported to snore frequently from the first month of life and who continued to snore frequently until 12 months of age had significantly lower cognitive development scores (mean=94.2 SD=3.9) compared to controls (mean=100.6 SD=3.7) (F (1, 96)=40 6, p<0.001 η(p)(2)=0.32). Persistent frequent snoring from the first month of life was associated with lower cognitive development scores at 12 months of age. It is possible that this deficit will become worse with age.
Publisher: IEEE
Date: 08-2014
Publisher: MDPI AG
Date: 25-05-2021
Abstract: The coronavirus disease 2019 (COVID-19) pandemic is widely understood to have contributed to mental health problems. In Australia, young people (18–24 years) have been disproportionately affected. To date, research has predominantly focused on the presence or absence of mental illness symptoms, while aspects of mental well-being have been overlooked. We aimed to explore associations between potential risk and protective factors and mental health more comprehensively, using the Complete State Model of Mental Health. An online survey of 1004 young Australians (55% female M age = 21.23) was undertaken. Assessment of both mental illness and mental well-being enabled participants to be cross-classified into four mental health states. Those with ‘Floundering’ (13%) or ‘Struggling’ (47.5%) mental health reported symptoms of mental illness a ‘Languishing’ group (25.5%) did not report symptoms of mental illness but mental well-being was compromised relative to those who were ‘Flourishing’ (14%) with high mental well-being. Multinomial logistic regressions were used to examine associations, adjusting for socio-demographic confounders. Protective factors associated with Flourishing mental health included being in secure employment, using screen time to connect with others, and reporting high levels of hope. Both incidental and purposive contact with nature were also associated with Flourishing, while a lack of green/bluespace within walking distance was associated with Languishing, absence of outdoor residential space was associated with Floundering, and lower neighbourhood greenness was associated with all three suboptimal mental health states. Precarious employment, financial stress, living alone, reporting decreased screen time during lockdowns, lower levels of hope, and high disruption of core beliefs were also associated with Struggling and Floundering mental health. Those who were Languishing reported somewhat less hardship and little disruption to core beliefs, but lower levels of hope compared to young people who were Flourishing. This study highlights that young adults require dedicated mental health services to deal with current burden, but should also be supported through a range of preventive strategies which target mental health risk factors, like precarious employment, and enhance protective factors, such as urban green infrastructure.
Publisher: Springer Science and Business Media LLC
Date: 16-11-2021
DOI: 10.1038/S41598-021-01772-8
Abstract: The capacity to regulate one’s attention in accordance with fluctuating task demands and environmental contexts is an essential feature of adaptive behavior. Although the electrophysiological correlates of attentional processing have been extensively studied in the laboratory, relatively little is known about the way they unfold under more variable, ecologically-valid conditions. Accordingly, this study employed a ‘real-world’ EEG design to investigate how attentional processing varies under increasing cognitive, motor, and environmental demands. Forty-four participants were exposed to an auditory oddball task while (1) sitting in a quiet room inside the lab, (2) walking around a sports field, and (3) wayfinding across a university c us. In each condition, participants were instructed to either count or ignore oddball stimuli. While behavioral performance was similar across the lab and field conditions, oddball count accuracy was significantly reduced in the c us condition. Moreover, event-related potential components (mismatch negativity and P3) elicited in both ‘real-world’ settings differed significantly from those obtained under laboratory conditions. These findings demonstrate the impact of environmental factors on attentional processing during simultaneously-performed motor and cognitive tasks, highlighting the value of incorporating dynamic and unpredictable contexts within naturalistic designs.
Publisher: IEEE
Date: 09-2015
Publisher: IEEE
Date: 08-2015
Publisher: Elsevier BV
Date: 09-2016
DOI: 10.1016/J.SLEEP.2016.06.011
Abstract: Successful sleep onset and maintenance is associated with a reduction in core temperature, facilitated by heat loss at the distal periphery. Problems with initiating and maintaining sleep in children with eczema may relate to impaired thermoregulatory mechanisms, which also contribute to itching and scratching. Our hypothesis was that nocturnal distal skin temperature in eczematous children would be lower than controls, and would also be related to poor sleep quality. We compared overnight polysomnography and distal (finger) and proximal (clavicle) skin temperature in 18 children with eczema and 15 controls (6-16 years). Children with eczema had longer periods of nocturnal wakefulness (mean [SD] = 88.8 [25.8] vs. 44.3 [35.6] min) and lower distal temperatures (34.1 [0.6] °C vs. 34.7 [0.4] °C) than controls, whereas proximal temperature and the distal-proximal gradient were not significantly different. In children with eczema, a higher distal temperature was associated with indicators of poor sleep quality, whereas lower distal temperature was related to more scratching events during sleep. In conclusion, our findings indicate complex interrelationships among eczema, thermoregulation and sleep, and further, that deficits in thermoregulatory mechanisms may contribute to sleep disturbances in children with eczema.
Publisher: Elsevier BV
Date: 05-2021
Publisher: S. Karger AG
Date: 29-06-2012
DOI: 10.1159/000339234
Abstract: b i Background/Aim: /i /b The contribution of cerebrovascular dysfunction to the manifestation of dementia and cognitive decline in late life is gaining increased attention. We aimed to systematically review evidence for associations between dementia or aging and cerebrovascular function as measured using transcranial Doppler (TCD) examination. b i Methods: /i /b A total of 1,172 articles were retrieved from PsychInfo and PubMed searches, and 34 relevant articles were identified using a variety of TCD methods. b i Results: /i /b The pulsatility index (vessel resistance), spontaneous emboli and cerebrovascular reactivity to hyper-/hypocapnia appeared good discriminators of dementia. Aging was associated with a slowing in blood flow velocity. b i Conclusion: /i /b TCD ultrasonography is inexpensive, portable and well tolerated by aged and demented subjects. The technique stands to make a valuable contribution to the knowledge regarding the underlying functional biology of age-related cognitive change and dementia.
Publisher: American Physiological Society
Date: 15-11-2012
DOI: 10.1152/JAPPLPHYSIOL.00756.2012
Abstract: Sleep-disordered breathing (SDB) in children is assessed by quantification of hypopnea and apnea events. Little is known, however, about respiratory timing and breath-to-breath variability during sleep. The aim of this study was to investigate respiratory parameters across sleep stages in children with SDB before and after treatment compared with healthy children. Overnight polysomnography (PSG) was conducted in 40 children with SDB prior to and 6 mo following adenotonsillectomy. For comparison, a control group of 40 healthy sex- and age-matched children underwent two PSGs at equivalent time points but without intervention. The following variables were measured breath by breath during obstruction-free periods in stage 2 nonrapid eye movement (NREM), stage 4 NREM, and REM sleep: inspiratory time (Ti), expiratory time (Te), total time (Ttotal), inspiratory duty cycle (DC =Ti/Ttotal), respiratory frequency (fR), and SD of the parameters Ti, Te, fR, and DC. Variability in waveform morphology was also computed using the residue of respiratory patterns. The severity of SDB was relatively mild in the study cohort (obstructive apnea hypopnea index: baseline, 5.1 ± 9.4 vs. 0.1 ± 0.2, P 0.001 follow-up, 0.3 ± 0.3 vs. 0.8 ± 1.0, P 0.01). Compared with healthy controls, children with SDB showed significantly longer Ti and Te and a lower fR at the baseline study. These differences were not significant after adenotonsillectomy. Sleep stages were associated with significant differences in all of the respiratory measures in both groups of children. In conclusion, children with relatively mild SDB showed prolonged inspiration and expiration indicative of chronic narrowing of the upper airway. Treatment of SDB normalizes respiratory timing. Documentation of these parameters may aid in both understanding and management of children with SDB.
Publisher: Elsevier BV
Date: 03-2011
DOI: 10.1016/J.SLEEP.2010.07.018
Abstract: Upper airway obstruction (UAO) during childhood is associated with cardiovascular morbidity. The aim of this study was to investigate the cardio-respiratory response to cortical arousal during sleep in children with UAO. Standard paediatric overnight polysomnography (PSG) was conducted in 40 children with UAO (25M, 7.5±2.7yrs) prior to and 6 months following adenotonsillectomy. For comparison a control group of 40 normal, sex and age matched children (21M, 7.5±2.6yrs) underwent two PSGs without intervention at the same time points. Heart rate and respiratory rate were measured during spontaneous and respiratory arousals in stage 2 and REM sleep 15s prior to and 15s immediately following cortical arousal onset. Cortical arousal was associated with a significant increase in heart and respiratory rate in both groups of children. UAO children, however, showed a significantly higher heart rate response in stage 2 sleep (-17.5±6.0 vs. -14.4±4.8% p<0.05), a lower pre-arousal baseline respiratory rate (stage 2: 17.1±1.4 vs. 18.2±1.7 BPM p<0.01) and a prolonged increase in respiratory rate compared to control children. Cardiac and respiratory arousal responses were not significantly different from controls following adenotonsillectomy in the UAO children. UAO in children is associated with an altered cardiorespiratory response to spontaneous arousal from sleep, which may indicate early signs of autonomic dysfunction. Surgical treatment of UAO appears to reverse these outcomes.
Publisher: Frontiers Media SA
Date: 31-01-2018
Publisher: Oxford University Press (OUP)
Date: 02-2013
DOI: 10.5665/SLEEP.2380
Publisher: Elsevier BV
Date: 03-2021
Publisher: American Psychological Association (APA)
Date: 09-2015
DOI: 10.1037/PAG0000026
Abstract: The brain is dependent on the cerebrovascular system, particularly microvasculature, for a consistent blood supply however, age-related changes in this system affect neuronal and therefore cognitive function. Structural vascular markers and vascular disease appear to preferentially affect fluid cognitive abilities, sparing crystallized abilities. We sought to investigate the relationships between cerebrovascular function and cognitive domains. Fifty in iduals between 60 and 75 years of age (31 women, 19 men) underwent cognitive testing: Wechsler Vocabulary and Matrix Reasoning subtests (crystallized and fluid ability measures, respectively Wechsler, 2011), and the Addenbrooke's Cognitive Examination-Revised (ACE-R general cognitive ability Mioshi, Dawson, Mitchell, Arnold, & Hodges, 2006). Transcranial Doppler (TCD) measures were also collected at rest and during a cognitive word-generation task, from which a lateralization index was calculated. Lower pulsatility index at rest, and greater left lateralization during the TCD cognitive task were associated with better performance on the Matrix Reasoning but not the Vocabulary test these effects were independent from each other and from any vascular comorbidity burden. These functional findings confirm previous structural studies, which revealed that fluid abilities are more vulnerable to cerebrovascular dysfunction than crystallized abilities, and identify two (likely related) mechanisms: degraded cerebrovascular integrity (indexed by pulsatility index) and a delateralization of function. Cerebrovascular dysfunction is a key contributor to cognitive aging that deserves further attention, particularly in relation to early diagnostic markers of impairment and monitoring of vascular (e.g., physical activity) interventions.
Publisher: Informa UK Limited
Date: 18-10-2018
DOI: 10.1080/09637486.2017.1386628
Abstract: This study aimed to compare sugar intake in Australian children with current guidelines and determine if total sugar consumption as a percentage of energy (sugar %E) exacerbates the relationship between sleep and behaviour. A s le of 287 children aged 8-12 years (boys 48.8%, age: 10.7 ± 1.3 years), and their parents/guardians completed a battery of questionnaires. Children completed a food frequency questionnaire, and parents completed demographic, sleep, and behaviour questionnaires. Average sugar intake was 134.9 ± 71.7 g per day (sugar %E 26.0 ± 7.0%), and only 55 (19%) participants did not exceed the recommended sugar intake limit. Correlations and logistical regressions indicated that sugar %E was not associated with sleep or behavioural domains (r range = -0.07-0.08 p range = .173-.979) nor contributed to the prediction of sleep behaviour problems (p range = .16-.80). Whilst a high proportion of children consumed above the recommended amount of daily total sugar, total sugar consumption was not related to behavioural or sleep problems, nor affected the relationship between these variables.
Publisher: Informa UK Limited
Date: 14-04-2016
DOI: 10.3109/07420528.2016.1167724
Abstract: Sleep inertia is a safety concern for shift workers returning to work soon after waking up. Split duty schedules offer an alternative to longer shift periods, but introduce additional wake-ups and may therefore increase risk of sleep inertia. This study investigated sleep inertia across a split duty schedule. Sixteen participants (age range 21-36 years 10 females) participated in a 9-day laboratory study with two baseline nights (10 h time in bed, [TIB]), four 24-h periods of a 6-h on/6-h off split duty schedule (5-h TIB in off period 10-h TIB per 24 h) and two recovery nights. Two complementary rosters were evaluated, with the timing of sleep and wake alternating between the two rosters (2 am/2 pm wake-up roster versus 8 am/8 pm wake-up roster). At 2, 17, 32 and 47 min after scheduled awakening, participants completed an 8-min inertia test bout, which included a 3-min psychomotor vigilance test (PVT-B), a 3-min Digit-Symbol Substitution Task (DSST), the Karolinska Sleepiness Scale (KSS), and the Samn-Perelli Fatigue Scale (SP-Fatigue). Further testing occurred every 2 h during scheduled wakefulness. Performance was consistently degraded and subjective sleepiness/fatigue was consistently increased during the inertia testing period as compared to other testing times. Morning wake-ups (2 am and 8 am) were associated with higher levels of sleep inertia than later wake-ups (2 pm and 8 pm). These results suggest that split duty workers should recognise the potential for sleep inertia after waking, especially during the morning hours.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2009
Publisher: Elsevier BV
Date: 12-2014
DOI: 10.1016/J.SLEEP.2014.08.011
Abstract: The aim of the study was to examine sleep, neurocognitive and behavioural functioning in children and adolescents with type 1 diabetes (T1D) compared to controls and to test whether sleep quality mediates the relationship between diabetes and neurocognitive and behavioural deficits. Participants include 49 children and adolescents with T1D (recruited from a hospital clinic) and 36 healthy controls (age range = 6-16 years). Parents completed a survey consisting of the Sleep Disturbances Scale for Children, the Behavior Rating Inventory of Executive Functions, and the Behavior Assessment System for Children-2. Diabetic and demographic parameters were collated from medical records. The survey was posted to participants. Children with T1D compared to controls reported a higher frequency of sleep problems, and mild deficits in executive and behavioural functioning. Mediational analyses revealed that sleep quality fully mediated metacognitive functioning, externalised problematic behaviour, and internalised problematic behaviour, but not behavioural regulation. Rather than the direct impact of T1D on daytime functioning, it is the consequent impact of T1D on sleep and the resulting sleep disruption which can explain much of the neurocognitive and behavioural deficits reported in children with T1D. Maintaining good nocturnal glycaemic control may play a much larger role than previously thought in regulating daytime functioning in children with T1D.
Publisher: Informa UK Limited
Date: 13-08-2017
Publisher: Informa UK Limited
Date: 08-2010
DOI: 10.2147/NSS.S6934
Publisher: Elsevier BV
Date: 05-2016
DOI: 10.1016/J.SLEEP.2016.02.002
Abstract: Cognitive decrements, problematic behaviors, and increased cerebral blood flow velocities (CBFVs) have been reported in children aged 3-7 years with sleep-disordered breathing (SDB). Whether similar impairments exist in younger children or those with behavioral insomnia of childhood (BIC) remains unclear. This study aimed to compare cognition and temperament in children aged 1-5 years with SDB or BIC to healthy control children, and to investigate whether cognitive or behavioral deficits associated with sleep problems are related to changes in CBFV. Toddlers and preschool-aged children (12-67 months) who had been referred for the clinical evaluation of SDB (n = 20) or BIC (n = 13) and a comparative s le of non-snoring healthy sleepers (controls n = 77) were recruited from the community. Children underwent cognitive assessment (Mullen's Scale of Early Learning) and measurement of resting bilateral CBFV in the middle cerebral artery (MCA) using Transcranial Doppler. Parents completed temperament scales (Early Childhood or Childhood Behavior Questionnaire), a sleep problem questionnaire (Pediatric Sleep Problem Survey Instrument) and performed home-based pediatric sleep monitoring (Actigraphy and Sleep Diary). SDB children demonstrated impaired receptive skills, more hyperactive and energetic temperaments, and higher bilateral CBFV than controls and children with BIC. Logistic regression analyses indicated that impaired cognition, temperamental difficulties, and increased CBFV are independently associated with SDB. During early childhood, problematic temperaments, cognitive deficits, and altered cerebrovascular functioning are associated with SDB but not BIC. CBFV does not appear to mediate these daytime deficits and instead may be an independent outcome of SDB. The findings support the need for an early intervention in pediatric SDB.
Publisher: Informa UK Limited
Date: 06-01-2014
DOI: 10.1080/17470919.2013.873737
Abstract: It is now common practice, in digital communication, to use the character combination ":-)", known as an emoticon, to indicate a smiling face. Although emoticons are readily interpreted as smiling faces, it is unclear whether emoticons trigger face-specific mechanisms or whether separate systems are utilized. A hallmark of face perception is the utilization of regions in the occipitotemporal cortex, which are sensitive to configural processing. We recorded the N170 event-related potential to investigate the way in which emoticons are perceived. Inverting faces produces a larger and later N170 while inverting objects which are perceived featurally rather than configurally reduces the litude of the N170. We presented 20 participants with images of upright and inverted faces, emoticons and meaningless strings of characters. Emoticons showed a large litude N170 when upright and a decrease in litude when inverted, the opposite pattern to that shown by faces. This indicates that when upright, emoticons are processed in occipitotemporal sites similarly to faces due to their familiar configuration. However, the characters which indicate the physiognomic features of emoticons are not recognized by the more laterally placed facial feature detection systems used in processing inverted faces.
Publisher: Cold Spring Harbor Laboratory
Date: 14-02-2020
DOI: 10.1101/2020.02.13.948539
Abstract: Language is one of the most defining human capabilities, involving the coordination of brain networks that generalise the meaning of linguistic units of varying complexity. On a neural level, neocortical slow oscillations and thalamic spindles during sleep facilitate the reactivation of newly encoded memory traces, manifesting in distinct oscillatory activity during retrieval. However, it is currently unknown if the effect of sleep on memory extends to the generalisation of the mechanisms that subserve sentence comprehension. We address this question by analysing electroencephalogram data recorded from 35 participants during an artificial language learning task and an 8hr nocturnal sleep period. We found that a period of sleep was associated with increased alpha/beta power and improved behavioural performance. Phase litude coupling analyses also revealed that spindle-slow oscillation coupling predicted the consolidation of sequence-based word orders, which was associated with distinct patterns of oscillatory activity during sentence processing. Taken together, this study presents converging behavioural and neurophysiological evidence for a role of sleep in the consolidation of higher order language learning and associated oscillatory neural activity.
Publisher: Public Library of Science (PLoS)
Date: 10-11-2016
Publisher: Elsevier BV
Date: 09-2016
DOI: 10.1016/J.SLEEP.2016.06.024
Abstract: Few studies have examined self-reported sleepwalking in older adolescents. The aim of this study was to examine the prevalence rates of sleepwalking in a one-month self-report period in Australian adolescents. Participants were 532 Australian adolescents in their final two years of secondary school. The prevalence of sleepwalking in the one-month self-report period was 2.9% (95% confidence interval (CI) 1.47-4.33) in this s le-1% reported sleepwalking at least once a week in the previous month. A significant proportion (17.5%) of the participants was unsure if they had sleepwalked. The results provide data on the self-reported prevalence rate of sleepwalking in older adolescents. Compared with the population data, this rate falls within the confidence intervals of child and adult prevalence rates of sleepwalking and is consistent with a decline in sleepwalking from childhood and adulthood. Further research is needed to explore how adolescents know they sleepwalk to understand the reliability of self-report measures.
Publisher: Informa UK Limited
Date: 12-2014
DOI: 10.2147/NSS.S54913
Publisher: Frontiers Media SA
Date: 23-08-2022
DOI: 10.3389/FSPOR.2022.907654
Abstract: Single-session meditation augmentation of sport-specific skill performance was tested with elite junior tennis athletes. Athletes completed one of two styles of mindfulness meditation (focused-attention or open-monitoring) or a control listening condition prior to performing an implicitly sequenced tennis serve return task involving the goal of hitting a target area placed on the service court. Unbeknownst to athletes, six distinct serves followed a repeating second-order conditional sequence for two task blocks before the sequence was altered in a third transfer block. Task performance was operationalized as serve return outcome and analyzed using beta regression modeling. Models analyzed group by block differences in the proportion of returned serves (i.e., non-aces), returns placed in the service court, and target hits. Contrary to previous laboratory findings, results did not support meditation-related augmentation of performance and/or sequence learning. In fact, compared to control, meditation may have impaired performance improvements and acquisition of serve sequence information. It is possible that the effects of single-session meditation seen in laboratory research may not extend to more complex motor tasks, at least in highly-trained adolescents completing a well-learned skill. Further research is required to elucidate the participant, task, and meditation-related characteristics that might promote single-session meditation performance enhancement.
Publisher: Elsevier BV
Date: 05-2015
DOI: 10.1016/J.SLEEP.2015.02.528
Abstract: Heartbeat-evoked potentials (HEPs) in electroencephalogram (EEG) provide a quantitative measure of cardiac interoception during sleep. We previously reported reduced HEPs in children with sleep-disordered breathing (SDB), indicative of attenuated cardiac information processing. The objective of this study was to investigate the link between HEP and respiration. From the overnight polysomnograms of 40 healthy children and 40 children with SDB, we measured HEPs during epochs of stage 2, slow-wave and rapid eye movement (REM) sleep free of abnormal respiratory events. HEPs were analysed with respect to respiratory phase. We observed a marked association between respiratory phase and HEP in children with SDB during REM sleep, but not in normal children. In children with SDB, HEP waveforms were attenuated during expiration compared to inspiration. Following adenotonsillectomy, expiratory HEP peak litude increased in the SDB children and was no longer different from those of normal children. The expiratory phase of respiration is primarily associated with attenuated cardiac information processing in children with SDB, establishing a pathophysiological link between breathing and HEP attenuation.
Publisher: Elsevier BV
Date: 11-2014
DOI: 10.1016/J.NEUBIOREV.2014.10.018
Abstract: The beneficial influence of sleep on memory consolidation is well established however, the mechanisms by which sleep can dynamically consolidate new memories into existing networks for the continued environmental adaptation of the in idual are unclear. The role of sleep in complex associative memory is an emerging field and the literature has not yet been systematically reviewed. Here, we systematically review the published literature on the role of sleep in complex associative memory processing to determine (i) if there is reasonable published evidence to support an active role for sleep facilitating complex associative processes such rule and gist extraction and false memory (ii) to determine which sleep physiological events and states impact these processes, and to quantify the strength of these relationships through meta-analysis. Twenty-seven studies in healthy adults were identified which combined indicate a moderate effect of sleep in facilitating associative memory as tested behaviourally. Studies which have measured sleep physiology have reported mixed findings. Significant associations between sleep electrophysiology and outcome appear to be based largely on mode of acquisition. We interpret these findings as supporting reactivation based models of associative processing.
Publisher: IEEE
Date: 03-2021
Publisher: Cold Spring Harbor Laboratory
Date: 27-05-2021
DOI: 10.1101/2021.05.27.445993
Abstract: The capacity to regulate one’s attention in accordance with fluctuating task demands and environmental contexts is an essential feature of adaptive behavior. Although the electrophysiological correlates of attentional processing have been extensively studied in the laboratory, relatively little is known about the way they unfold under more variable, ecologically-valid conditions. Accordingly, this study employed a ‘real-world’ EEG design to investigate how attentional processing varies under increasing cognitive, motor, and environmental demands. Forty-four participants were exposed to an auditory oddball task while (1) sitting in a quiet room inside the lab, (2) walking around a sports field, and (3) wayfinding across a university c us. In each condition, participants were instructed to either count or ignore oddball stimuli. While behavioral performance was similar across the lab and field conditions, oddball count accuracy was significantly reduced in the c us condition. Moreover, event-related potential components (mismatch negativity and P3) elicited in both ‘real-world’ settings differed significantly from those obtained under laboratory conditions. These findings demonstrate the impact of environmental factors on attentional processing during simultaneously-performed motor and cognitive tasks, highlighting the value of incorporating dynamic and unpredictable contexts within naturalistic designs.
Publisher: ACM
Date: 06-05-2021
Publisher: Wiley
Date: 12-03-2018
DOI: 10.1111/JSR.12682
Abstract: This study examined the associations between self-reported sleep timing and quality, and the frequency of breakfast and junk food consumption in 28,010 Australian school students (mean ± SD age = 13.3 ± 1.2 years, 51% male). After controlling for age, sex and socioeconomic status, regression analyses revealed that the odds of missing breakfast were significantly higher in children who reported poor sleep or later bedtimes, while the odds of junk food consumption were significantly higher in children reporting later weeknight bedtimes (p < 0.001). These findings suggest that sleep timing and quality influence the dietary choices of adolescents.
Publisher: Wiley
Date: 02-2012
DOI: 10.1111/J.1440-1754.2011.02059.X
Abstract: Disruptions to sleep in childhood are associated with poor behaviour and deficits in academic performance and executive function. Although academic performance of indigenous children from remote communities in Australia is documented as well below that of non-indigenous children, the extent of sleep disruption and its contribution to academic performance among this population has not been assessed. This pilot study aimed to objectively assess the sleep of remote indigenous children and the association between sleep disruption and both academic performance and executive function. Twenty-one children from a remote Australian indigenous community aged 6-13 years wore actigraphy for two consecutive nights, reported subjective sleepiness, and were objectively assessed for academic performance (Wechsler In idual Achievement Test, 2nd Edition) and executive function (NEuroloPSYcological Assessment-II). Results show marked reduction in sleep time, sleep fragmentation, academic performance and auditory attention compared with non-indigenous norms. Sleep duration was not associated with performance, possibly because of reduced sleep and performance observed across the entire group. Sleep fragmentation was associated with reduced reading and numerical skills (P < 0.05). The sleep of indigenous children in remote communities is an important area of future inquiry, and our initial findings of poor sleep and an association between sleep disruption and academic performance may have important implications for intervention strategies aimed at 'closing the gap'. Further studies should assess a broader range of demographic, social and economic factors to better understand the associations reported here and guide future intervention.
Publisher: IEEE
Date: 04-2013
Publisher: Cold Spring Harbor Laboratory
Date: 10-03-2022
DOI: 10.1101/2020.03.10.984971
Abstract: Memory formation involves the synchronous firing of neurons in task-relevant networks, with recent models postulating that a decrease in low frequency oscillatory activity underlies successful memory encoding and retrieval. However, to date, this relationship has been investigated primarily with face and image stimuli considerably less is known about the oscillatory correlates of complex rule learning, as in language. Further, recent work has shown that non-oscillatory (1/ f ) activity is functionally relevant to cognition, yet its interaction with oscillatory activity during complex rule learning remains unknown. Using spectral decomposition and power-law exponent estimation of human EEG data (17 females, 18 males), we show for the first time that 1/ f and oscillatory activity jointly influence the learning of word order rules of a miniature artificial language system. Flexible word order rules were associated with a steeper 1/ f slope, while fixed word order rules were associated with a shallower slope. We also show that increased theta and alpha power predicts fixed relative to flexible word order rule learning and behavioural performance. Together, these results suggest that 1/ f activity plays an important role in higher-order cognition, including language processing, and that grammar learning is modulated by different word order permutations, which manifest in distinct oscillatory profiles.
Publisher: Springer Science and Business Media LLC
Date: 06-03-2015
DOI: 10.1007/S11325-014-0963-3
Abstract: This study aims to investigate the impact of upper airway obstruction (UAO) in children by measuring thoracoabdominal asynchrony (TAA) during periods of sleep apnea/hypopnea and during scored-event-free (SEF) breathing periods. Respiratory inductive plethysmographic signals were extracted from polysomnographic data, recorded before and after adenotonsillectomy in 40 children with UAO and 40 healthy, matched children at equivalent time points. Thoracoabdominal asynchrony was computed using a Hilbert transform-based phase difference estimation method in SEF periods during stage 2, stage 4 non-rapid eye movement (NREM), and rapid eye movement (REM) sleep and compared between the groups. At baseline, in the UAO group, TAA during obstructions were significantly higher than TAA during SEF periods in both stage 2 and REM sleep. Compared to controls, children with UAO had a significantly higher TAA during SEF periods in stage 2, stage 4 sleep, and REM sleep. This between-group difference was not significant post adenotonsillectomy. UAO group showed a significant decrease in TAA compared to their baseline during SEF stage 2 and 4 NREM, but not in REM. Upper airway obstruction in children is associated with increased TAA during SEF periods, indicative of continuous partial obstruction of the upper airway. Adenotonsillectomy decreased this effect significantly in non-REM sleep as evidenced by reduced asynchrony levels post-surgery. TAA assessment during sleep may therefore provide additional diagnostic information.
Publisher: Springer Science and Business Media LLC
Date: 06-03-2014
Publisher: Cold Spring Harbor Laboratory
Date: 12-10-2017
DOI: 10.1101/202176
Abstract: Sleep promotes memory consolidation through unique neuromodulatory activity. However, little is known about the impact of attention during pre-sleep memory encoding on later memory performance. The current study aimed to address the question of whether attentional state prior to encoding, as indexed by alpha oscillatory activity, modulates the consolidation of images across periods of sleep and wake. 22 participants aged 18 – 41 years (mean age = 27.3) viewed 120 emotionally valenced images (positive, negative, neutral) before a 2hr afternoon sleep opportunity and an equivalent period of wake. Following the sleep and wake conditions, participants were required to distinguish between 120 previously seen (target) images and 120 new (distractor) images. Relative alpha power – adjusted according to participants’ in idual alpha frequency – was computed to index attentional state prior to the learning phase. Generalised linear mixed-effects modelling revealed memory performance was modulated by attention, such that greater pre-encoding alpha power preferentially promoted memory consolidation during wake compared to sleep. There was no difference in memory performance between positive, negative and neutral stimuli. Modulations in alpha oscillatory activity may help to coordinate the flow of information between task-relevant cortical regions and a thalamo-cortical loop that preferentially subserves the formation of memory during times of wake relative to sleep.
No related grants have been discovered for Mark Kohler.