Event-related Potentials reveal differential Brain Regions implicated in Discounting in Two Tasks

The way people make decisions about future benefits – termed discounting - has important implications for both financial planning and health behaviour. Several theories assume that, when delaying gratification, the lower weight given to future benefits (the discount rate) declines exponentially. However there is considerable evidence that it declines hyperbolically with the rate of discount being proportionate to the delay distance. There is relatively little evidence as to whether neural areas mediating time- dependent discounting processes differ according to the nature of the task. The present study investigates the potential neurological mechanisms underpinning domain-specific discounting processes. We present high-density event-related potentials (ERPs) data from a task in which participants were asked to make decisions about financial rewards or their health over short and long time-horizons. Participants (n=17) made a button-press response to their preference for an immediate or delayed gain (in the case of finance) or loss (in the case of health), with the discrepancy in the size of benefits/losses varying between alternatives. Waveform components elicited during the task were similar for both domains and included posterior N1, frontal P2 and posterior P3 components. We provide source dipole evidence that differential brain activation does occur across domains with results suggesting the possible involvement of the right cingulate gyrus and left claustrum for the health domain and the left medial and right superior frontal gyri for the finance domain. However, little evidence for differential activation across time horizons is found.Decision Making, Domain-Specific Discounting, Event-Related Potentials

Event-Related Potentials Reveal Differential Brain Regions Implicated in Discounting in Two Tasks

The way people make decisions about future benefits termed discounting - has important implications for both financial planning and health behaviour. Several theories assume that, when delaying gratification, the lower weight given to future benefits (the discount rate) declines exponentially. However there is considerable evidence that it declines hyperbolically with the rate of discount being proportionate to the delay distance. There is relatively little evidence as to whether neural areas mediating timedependent discounting processes differ according to the nature of the task. The present study investigates the potential neurological mechanisms underpinning domain-specific discounting processes. We present high-density event-related potentials (ERPs) data from a task in which participants were asked to make decisions about financial rewards or their health over short and long time-horizons. Participants (n=17) made a button-press response to their preference for an immediate or delayed gain (in the case of finance) or loss (in the case of health), with the discrepancy in the size of benefits/losses varying between alternatives. Waveform components elicited during the task were similar for both domains and included posterior N1, frontal P2 and posterior P3 components. We provide source dipole evidence that differential brain activation does occur across domains with results suggesting the possible involvement of the right cingulate gyrus and left claustrum for the health domain and the left medial and right superior frontal gyri for the finance domain. However, little evidence for differential activation across time horizons is found.

Children and young people’s experiences and perceptions of self-management of type 1 diabetes: A qualitative meta-synthesis

The aim of this review was to conduct a meta-synthesis of the experiences and perceptions of self-management of type 1 diabetes of children and young people living with type 1 diabetes (CYPDs). Six databases were systematically searched for studies with qualitative findings relevant to CYPDs’ (aged 8–18 years) experiences of self-management. A thematic synthesis approach was used to combine articles and identify analytical themes. Forty articles met the inclusion criteria. Two analytical themes important to CYPDs’ experiences and perceptions of self-management were identified: (1) negotiating independence and (2) feeling in control. The synthesis contributes to knowledge on contextual factors underpinning self-management and what facilitates or impedes transition towards autonomous self-management for CYPDs

Reduced duration mismatch negativity in adolescents with psychotic symptoms: further evidence for mismatch negativity as a possible biomarker for vulnerability to psychosis

Background: Deficits in the mismatch negativity (MMN) and P3a components are the most reliable and robust findings in schizophrenia. These abnormalities have also been recently documented in individuals clinically at risk for psychosis, indicating that the MMN may be a potential biomarker for psychosis. However, the at risk samples included in MMN studies are characterised by pre-existing clinical symptomatology and significant functional decline which are related to MMN amplitude. These factors may be potential confounds in determining whether deficient MMN is present prior to clinical manifestation of the disorder. Therefore, investigating the MMN in the extended psychosis phenotype comprising adolescents with psychotic symptoms from the general population may provide important information on whether abnormal MMN is apparent in the earliest stages of risk. Methods: Thirty six adolescents completed a duration deviant MMN task. Fourteen adolescents with psychotic symptoms comprised the at risk group and 22 with no psychotic symptoms comprised the Controls. The task consisted of 85% standard tones (25 ms) and 15% deviant tones (50 ms). The groups were compared on MMN and P3a amplitude and latency across frontocentral and temporal electrodes. Results: Adolescents with psychotic symptoms were characterised by a reduction in MMN amplitude at frontal and temporal regions compared to the controls. Conclusions: This is the first study to demonstrate impaired auditory discrimination for duration deviant tones in nonclinical adolescents with psychotic symptoms. These findings suggest that MMN amplitude may be a possible biomarker for vulnerability to psychosis

Parents’ perspectives of factors affecting parent–adolescent communication about type 1 diabetes and negotiation of self-management responsibilities

Adolescence is an important time in which young people take on type 1 diabetes (T1D) self-management responsibility. Parents are key facilitators of this process. Little is known about parents’ experiences of communicating with their children about T1D during adolescence. Semi-structured interviews were conducted with 32 parents (24 mothers and 8 fathers) of adolescents (11–17 years) living with T1D to explore how parents communicate about T1D and self-management with their adolescent children. Parents were recruited through two national child and adolescent diabetes and endocrine clinics and online advertisement through a national diabetes advocacy organisation. Interviews were transcribed verbatim and thematically analysed. Six themes were identified: parent factors, quality of the parent–adolescent relationship, communication strategies, adolescent factors, communication triggers and family/system factors. Understanding factors that impact communication about self-management between parents and adolescents will enable healthcare professionals to provide support and targeted interventions as parent and adolescent roles change over time

Reduced P300 amplitude during retrieval on a spatial working memory task in a community sample of adolescents who report psychotic symptoms.

BACKGROUND: Deficits in working memory are widely reported in schizophrenia and are considered a trait marker for the disorder. Event-related potentials (ERPs) and imaging data suggest that these differences in working memory performance may be due to aberrant functioning in the prefrontal and parietal cortices. Research suggests that many of the same risk factors for schizophrenia are shared with individuals from the general population who report psychotic symptoms. METHODS: Forty-two participants (age range 11--13 years) were divided into those who reported psychotic symptoms (N = 17) and those who reported no psychotic symptoms, i.e. the control group (N = 25). Behavioural differences in accuracy and reaction time were explored between the groups as well as electrophysiological correlates of working memory using a Spatial Working Memory Task, which was a variant of the Sternberg paradigm. Specifically, differences in the P300 component were explored across load level (low load and high load), location (positive probe i.e. in the same location as shown in the study stimulus and negative probe i.e. in a different location to the study stimulus) and between groups for the overall P300 timeframe. The effect of load was also explored at early and late timeframes of the P300 component (250-430 ms and 430-750 ms respectively). RESULTS: No between-group differences in the behavioural data were observed. Reduced amplitude of the P300 component was observed in the psychotic symptoms group relative to the control group at posterior electrode sites. Amplitude of the P300 component was reduced at high load for the late P300 timeframe at electrode sites Pz and POz. CONCLUSIONS: These results identify neural correlates of neurocognitive dysfunction associated with population level psychotic symptoms and provide insights into ERP abnormalities associated with the extended psychosis phenotype

Electrophysiological Correlates of Cognitive Processing in Adolescents Reporting Psychotic-Like Experiences

Psychotic disorders are often preceded by impaired cognitive functioning. Self-reported psychotic symptoms during adolescence have been associated with the development of a psychotic disorder in adulthood (Poulton et al., 2000; Welham et al., 2009a; 2009b). Adolescents who report psychotic-like experiences (PLEs; the non-clinical psychosis phenotype) have been shown to share many of the same schizophrenia-related risk factors as patients with schizophrenia (the clinical psychosis phenotype; Kelleher & Cannon, 2011). The following thesis employs both behavioural and electrophysiological methods in an attempt to uncover possible correlates of PLEs in a community-based sample of young adolescent participants compared to a control group. Electroencephalographic (EEG) recording took place following a detailed clinical interview and neuropsychological testing. Neuropsychological functioning and resting state EEG data were examined. Three tasks which investigate capacities which have been proposed as trait markers for schizophrenia were chosen for use with EEG. These tasks were an Active Auditory Oddball Task, an Implicit Spatial Memory Task and a Spatial Working Memory Task. The present thesis is the first study to examine resting state data and the electrophysiological correlates of auditory and spatial processing in adolescents reporting PLEs. In Chapter 3 the MATRICS Consensus Cognitive Battery (MCCB) was employed to test group differences on a number of tests of neuropsychological functioning. Chapter 3 also examines quantitative EEG spectral power in the delta (1.5-3.5Hz), theta (3.5-7.5Hz) and alpha (7.5-12.5Hz) frequency bands during resting state recordings in which participants had their eyes open for two minutes and eyes closed for an additional two minutes. Adolescents reporting PLEs scored more poorly on two measures of speed of processing. No between-group differences were observed in the resting state data at anterior, posterior or fronto-temporal scalp locations. In Chapter 4 an Active Auditory Oddball Task was employed to test group differences in the P300 event-related potential (ERP) and the N100 auditory evoked potential (AEP). Reduced amplitude of the P300 ERP to target tones has been reported in patients with schizophrenia, first-episode psychosis (FEP), groups at genetic high risk for psychosis and, most recently, in clinical at-risk groups. Reduced amplitude of the N100 AEP to non-target tones has also been reported in schizophrenia patients and first-degree relatives of patients. An increase in the amplitude of the N100 AEP component to non-target tones was observed in the PLEs group in the present thesis. No between-group-differences in mean amplitude of the P300 component to target tones were observed; however, mean amplitude to target tones at FCz was found to be significantly greater than mean amplitude to non-target tones in the control group but not in the PLEs group at fronto-central locations. Chapters 5 and 6 investigated spatial processing and spatial working memory, respectively. No between-group differences were observed in the behavioural or electrophysiological data obtained from the Implicit Spatial Memory Task. Data from the Spatial Working Memory Task revealed no between-group differences for accuracy or reaction time. Greater reaction time variability was observed in the PLEs group relative to control group however. Reduced mean amplitude of the P300 component was observed in the PLEs group relative to the control group at parietal electrode sites. The present thesis adds to the knowledge of PLEs in early adolescence by reporting reduced P300 during spatial working memory retrieval in this group while spatial processing and memory (as assessed by the Implicit Spatial Memory Task) remain unimpaired. This reduction in P300 amplitude may reflect disrupted neural processes underlying stimulus evaluation and template matching during retrieval in the PLEs group. The finding of reduced P300 in the PLEs group on the Spatial Working Memory Task adds to previous findings of impaired spatial working memory in this group reported by Kelleher et al. (2012c), and expands existing findings of reduced P300 amplitude in adolescent onset schizophrenia (Haenschel et al., 2007) by revealing reduced P300 amplitude in the treatment-naïve extended psychosis phenotype

Early intervention and child health: Evidence from a Dublin-based randomized controlled trial

This article investigates the impact of an early intervention program, which experimentally modifies the parenting and home environment of disadvantaged families, on child health in the first 3 years of life. We recruited and randomized 233 (115 intervention, 118 control) pregnant women from a socioeconomically disadvantaged community in Dublin, Ireland into an intervention or control group. The treatment includes regular home visits commencing antenatally and an additional parenting course commencing at 2 years. Maternal reports of child health are assessed at 6, 12, 18, 24, and 36 months. Treatment effects are estimated using permutation testing to account for small sample size, inverse probability weighting to account for differential attrition, and the stepdown procedure to account for multiple hypothesis testing. Following adjustment for multiple testing and attrition, we observe a positive and statistically significant main treatment effect for wheezing/asthma. The intervention group are 15.5 percentage points (pp) less likely to require medical attention for wheezing/asthma compared to the control group. Statistically significant individual main effects which do not survive multiple testing and IPW-adjustment are found for general health (10.0 pp), hospitalizations (8.2 pp), immunizations (8.6 pp), chest infections (12.2 pp) and the number of health problems (d = 0.34). Subgroup analysis reveals more statistically significant adjusted treatment effects for boys than girls regarding fewer health problems (d = 0.63), accidents (23.9 pp), and chest infections (22.8 – 37.9 pp). Our results suggest that a community-based home visiting program may have favorable impacts on early health conditions. As child ill health is costly to society due to an increased demand on health resources and long-term productivity losses, identifying effective interventions to counteract inequalities in health is important from a policy perspective

Event-related potentials reveal differential brain regions implicated in discounting in two tasks

The way people make decisions about future benefits – termed discounting - has important implications for both financial planning and health behaviour. Several theories assume that, when delaying gratification, the lower weight given to future benefits (the discount rate) declines exponentially. However there is considerable evidence that it declines hyperbolically with the rate of discount being proportionate to the delay distance. There is relatively little evidence as to whether neural areas mediating time dependent discounting processes differ according to the nature of the task. The present study investigates the potential neurological mechanisms underpinning domain-specific discounting processes. We present high-density event-related potentials (ERPs) data from a task in which participants were asked to make decisions about financial rewards or their health over short and long time-horizons. Participants (n=17) made a button-press response to their preference for an immediate or delayed gain (in the case of finance) or loss (in the case of health), with the discrepancy in the size of benefits/losses varying between alternatives. Waveform components elicited during the task were similar for both domains and included posterior N1, frontal P2 and posterior P3 components. We provide source dipole evidence that differential brain activation does occur across domains with results suggesting the possible involvement of the right cingulate gyrus and left claustrum for the health domain and the left medial and right superior frontal gyri for the finance domain. However, little evidence for differential activation across time horizons is found