Memory development and event-related brain potentials in children

A correlational study between microstructural, macrostructural and functional age-related changes in the human visual cortex

Age-related changes in the human brain can be investigated from either structural or functional perspectives. Analysis of structural and functional age-related changes throughout the lifespan may help to understand the normal brain development process and monitor the structural and functional pathology of the brain. This study, combining dedicated electroencephalography (EEG) and magnetic resonance imaging (MRI) approaches in adults (20-78 years), highlights the complex relationship between micro/macrostructural properties and the functional responses to visual stimuli. Here, we aimed to relate age-related changes of the latency of visual evoked potentials (VEPs) to micro/macrostructural indexes and find any correlation between micro/macrostructural features, as well. We studied age-related structural changes in the brain, by using the MRI and diffusion-weighted imaging (DWI) as preferred imaging methods for extracting brain macrostructural parameters such as the cortical thickness, surface area, folding and curvature index, gray matter volume, and microstructural parameters such as mean diffusivity (MD), radial diffusivity (RD) and axial diffusivity (AD). All the mentioned features were significantly correlated with age in V1 and V2 regions of the visual cortex. Furthermore, we highlighted, negative correlations between structural features extracted from T1-weighted images and DWI. The latency and amplitude of the three dominants peaks (C1, P1, N1) of the VEP were considered as the brain functional features to be examined for correlation with age and structural features of the corresponding age. We observed significant correlations between mean C1 latency and GM volume averaged in V1 and V2. In hierarchical regression analysis, the structural index did not contribute to significant variance in the C1 latency after regressing out the effect of age. However, the age explained significant variance in the model after regressing out the effect of structural feature.

Memory dysfunctions

Since the seminal work on the patient HM, who in his adulthood presented an acquired amnesic syndrome following the resection of the bilateral temporal lobe, other research has described several cases of isolated memory dysfunction in children. This chapter presents developmental and long-lasting memory disorders emerging from an organic or neurologic cause at birth or in infancy. More notably, we focus on developmental amnesic syndrome caused by neonatal bihippocampal damage and memory dysfunction caused by medial temporal developmental epilepsy. We describe these two pediatric populations and present the consequences of hippocampal/medial temporal lobe damage in the development of memory systems. We review episodic memory deficits in children with developmental amnesia and temporal lobe epilepsy and highlight their impact on new learning, personal memories, and independent life. Finally, we provide a brief overview of some of the insights and debates emerging from classic work and recent advances in the context of episodic memory dysfunction displayed by children with hippocampal/medial temporal lobe amnesia and propose new perspectives in child neuropsychology of memory, suggesting new avenues for more ecologic memory assessment and rehabilitation.

Single-Trial Mechanisms Underlying Changes in Averaged P300 ERP Amplitude and Latency in Military Service Members After Combat Deployment

Attenuation in P300 amplitude has been characterized in a wide range of neurological and psychiatric disorders such as dementia, schizophrenia, and posttraumatic stress disorder (PTSD). However, it is unclear whether the attenuation observed in the averaged event-related potential (ERP) is due to the reduction of neural resources available for cognitive processing, the decreased consistency of cognitive resource allocation, or the increased instability of cognitive processing speed. In this study, we investigated this problem by estimating single-trial P300 amplitude and latency using a modified Woody filter and examined the relation between amplitudes and latencies from the single-trial level to the averaged ERP level. ERPs were recorded from 30 military service members returning from combat deployment at two time points separated by 6 or 12 months. A conventional visual oddball task was used to elicit P300. We observed that the extent of changes in the within-subject average P300 amplitude over time was significantly correlated with the amount of change in three single-trial measures: (1) the latency variance of the single-trial P300 (r = -0.440, p = 0.0102); (2) the percentage of P300-absent trials (r = -0.488, p = 0.005); and (3) the consistent variation of the single-trial amplitude (r = 0.571, p = 0.0022). These findings suggest that there are multiple underlying mechanisms on the single-trial level that contribute to the changes in amplitudes seen at the averaged ERP level. The changes between the first and second assessments were quantified with the intraclass correlation coefficient, the standard error of measurement and the minimal detectable difference. The unique population, the small sample size and the large fraction of participants lost to follow up precludes generalizations of these measures of change to other populations.

Orienting and memory to unexpected and/or unfamiliar visual events in children and adults

For children, new experiences occur very often, and learning to differentiate between old and new events is a fundamental process necessary for appropriate reactions to stimuli. Thus the present study is concerned with maturation of brain responses to repeated novel events. We examined the effect of repetition of familiar (meaningful) and unfamiliar (meaningless) symbols on the event-related-potentials (ERPs) recorded during novelty oddball and recognition memory tasks from children, adolescents and young adults. During the novelty oddball task, repetition of the familiar symbols elicited a reduction in the novelty P3 in the ERPs of all age groups, while repetition of the unfamiliar symbols elicited a reduction in novelty P3 amplitude only in children. As expected, recognition memory performance improved with age and was better for familiar than unfamiliar symbols. For all age groups, ERPs to correctly recognized familiar old symbols elicited a larger positivity than ERPs to correctly identified new symbols, indicating a reliable memory effect. However, ERPs to unfamiliar old and new symbols did not differ in adults and adolescents but did differ in children. The data suggest that children process familiar visual symbols in a similar fashion to that of adults, and that children process unfamiliar symbols differently from adults.

Determinants of memory development in childhood and adolescence

Research on the development of memory has a long history and constitutes one of the most active research areas in the field of cognitive development. In this article, we first describe major historical developments in the literature on children's memory, focusing on systematic research that began in the late 1960s. We then examine new developments in the field, describing four important lines of inquiry: (a) the development of implicit memory, (b) short- and long-term memory development in infancy, (c) longitudinal research on memory strategies and metamemory, and (d) developmental cognitive neuroscience of memory. Finally, promising lines of future research on memory development are briefly discussed.

Development of Performance and ERPs in a Flanker Task in Children and Adolescents with Tourette Syndrome-A Follow-Up Study

Background: Tourette Syndrome (TS) is a neurodevelopmental disorder with childhood-onset, with a typical decline in tic severity, as well as an increasing ability to suppress tics in late childhood and adolescence. These processes develop in parallel with general improvement of self-regulatory abilities, and performance monitoring during this age-span. Hence, changes in performance monitoring over time might provide insight into the regulation of tics in children and adolescents with TS.

Method: We measured reaction time, reaction time variability, accuracy, and event-related potentials (ERP) in 17 children with TS, including 10 children with comorbid Attention-Deficit/Hyperactivity Disorder (ADHD), 24 children with ADHD, and 29 typically developing children, using a modified Eriksen Flanker task in two testing sessions administered on average 4.5 years apart. We then compared task performance, as well as ERP components across groups, and over time using regression models.

Results: Task performance improved in all groups with age, and behavioral differences between children with TS and controls diminished at second assessment, while differences between controls and children with ADHD largely persisted. In terms of ERP, the early P3 developed earlier in children with TS compared with controls at the first assessment, but trajectories converged with maturation. ERP component amplitudes correlated with worst-ever tic scores.

Conclusions: Merging trajectories between children with TS and controls are consistent with the development of compensatory self-regulation mechanisms during early adolescence, probably facilitating tic suppression, in contrast to children with ADHD. Correlations between ERP amplitudes and tic scores also support this notion.

Event-related potential study of intentional and incidental retrieval of item and source memory during early childhood

The event related potential (ERP) technique is a useful methodology for studying neural changes underlying memory development during childhood. However, systematic comparisons of differences in memory tasks and retrieval demands are lacking. To address this gap, the present study explored the effects of memory task (i.e., item versus source) and retrieval paradigm (i.e., intentional versus incidental) on 4- to 5-year-old children's memory performance and associated electrophysiological responses. Children were familiarized with items in a play-like setting and then asked to retrieve item or source memory details while their brain activity was recorded (intentional retrieval) or while they passively viewed images of the items with no explicit task (incidental retrieval). Memory assessments for the incidental groups followed ERP recording. Analyses of the ERP data suggested that the brain's response during intentional retrieval of source information differed from the other three conditions. These results are discussed within a two-component framework of memory development (e.g., Shing et al., 2010), and implications for future methodological decisions are presented. © 2016 Wiley Periodicals, Inc. Dev Psychobiol 58: 556-567, 2016.

Performance Monitoring in Medication-Naïve Children with Tourette Syndrome

Background: Tourette syndrome (TS) is a childhood-onset neurodevelopmental disorder and its impact on cognitive development needs further study. Evidence from neuropsychological, neuroimaging and electrophysiological studies suggests that the decline in tic severity and the ability to suppress tics relate to the development of self-regulatory functions in late childhood and adolescence. Hence, tasks measuring performance monitoring might provide insight into the regulation of tics in children with TS.

Method: Twenty-five children with TS, including 14 with comorbid Attention-deficit/ hyperactivity disorder (ADHD), 39 children with ADHD and 35 typically developing children aged 8–12 years were tested with a modified Eriksen-Flanker task during a 34-channel electroencephalography (EEG) recording. Task performance, as well as stimulus-locked and response-locked event-related potentials (ERP) were analyzed and compared across groups.

Results: Participants did not differ in their behavioral performance. Children with TS showed higher amplitudes of an early P3 component of the stimulus-locked ERPs in ensemble averages and in separate trial outcomes, suggesting heightened orienting and/or attention during stimulus evaluation. In response-locked averages, children with TS had a slightly higher positive complex before the motor response, likely also reflecting a late P3. Groups did not differ in post-response components, particularly in the error-related negativity (ERN) and error-related positivity (Pe).

Conclusions: These findings suggest that children with TS may employ additional attentional resources as a compensatory mechanism to maintain equal behavioral performance.

From perception to memory: changes in memory systems across the lifespan

Human memory is not a unitary entity; rather it is thought to arise out of a complex architecture involving interactions between distinct representational systems that specialize in perceptual, semantic, and episodic representations. Neuropsychological and neuroimaging evidence are combined in support of models of memory systems, however most models only capture a 'mature' state of human memory and there is little attempt to incorporate evidence of the contribution of developmental and senescence changes in various processes involved in memory across the lifespan. Here we review behavioral and neuroimaging evidence for changes in memory functioning across the lifespan and propose specific principles that may be used to extend models of human memory across the lifespan. In contrast to a simplistic reduced version of the adult model, we suggest that the architecture and dynamics of memory systems become gradually differentiated during development and that a dynamic shift toward favoring semantic memory occurs during aging. Characterizing transformations in memory systems across the lifespan can illustrate and inform us about the plasticity of human memory systems.

Associative learning measured with ERP predicts deferred imitation using a strict observation only design in 14 to 15 month old children

Deferred imitation (DI) is an established procedure for behavioral measurement of early declarative-like memories in infancy and previous work has indicated a link between this type of memory and brain potentials in infants. The present study compared infants' memory performance in this paradigm with electrophysiological indices of associative learning. Thirty children (M = 14.5 months) participated, of which 15 (8 boys) had acceptable event-related potentials (ERP) recordings that could be included in the final analysis. Deferred imitation was measured with an observation-only procedure using three actions and a 30 min delay. ERP was recorded with a high-density electrode net (128 electrodes) during associative learning. Change scores based on Nc, a middle latency component associated with attentional processes, predicted deferred imitation performance. Thus, associative learning measured with ERP predicts deferred imitation using a strict observation only design in 14 to 15 month old children.

Iron deficiency in infancy is associated with altered neural correlates of recognition memory at 10 years

OBJECTIVE

To determine the long-term effects of iron deficiency on the neural correlates of recognition memory.

STUDY DESIGN

Non-anemic control participants (n=93) and 116 otherwise healthy formerly iron-deficient anemic Chilean children were selected from a larger longitudinal study. Participants were identified at 6, 12, or 18 months as iron-deficient anemic or non-anemic and subsequently received oral iron treatment. This follow-up was conducted when participants were 10 years old. Behavioral measures and event-related potentials from 28 scalp electrodes were measured during an new/old word recognition memory task.

RESULTS

The new/old effect of the FN400 amplitude, in which new words are associated with greater amplitude than old words, was present within the control group only. The control group also showed faster FN400 latency than the formerly iron-deficient anemic group and larger mean amplitude for the P300 component.

CONCLUSIONS

Although overall behavioral accuracy is comparable in groups, the results show that group differences in cognitive function have not been resolved 10 years after iron treatment. Long-lasting changes in myelination and energy metabolism, perhaps especially in the hippocampus, may account for these long-term effects on an important aspect of human cognitive development.

A "snapshot" of declarative memory: Differing developmental trajectories in episodic and autobiographical memory

Episodic and autobiographical memory are clearly related, yet in both the adult and developmental literatures it is difficult to compare them because of differences in how the constructs are assessed, including differences in content, levels of control, and time since experience. To address these issues, we directly compared children's and adults' autobiographical and episodic memory using the same controlled paradigm. Participants engaged in a photo-taking activity in a museum (autobiographical encoding) and viewed others' photographs of the same museum exhibits (episodic encoding). At test, participants classified photos as ones they took, viewed, or novel. In the autobiographical condition older children and adults performed similarly; younger children's performance was lower than adults'. In contrast, in the episodic condition both groups of children performed more poorly than adults. The findings suggest the developmental primacy of autobiographical relative to episodic memory, and that traditional episodic tasks may underestimate older children's declarative memory abilities.

Age-related differences in brain electrical activity during extended continuous face recognition in younger children, older children and adults

To examine the development of recognition memory in primary-school children, 36 healthy younger children (8-9 years old) and 36 healthy older children (11-12 years old) participated in an ERP study with an extended continuous face recognition task (Study 1). Each face of a series of 30 faces was shown randomly six times interspersed with distracter faces. The children were required to make old vs. new decisions. Older children responded faster than younger children, but younger children exhibited a steeper decrease in latencies across the five repetitions. Older children exhibited better accuracy for new faces, but there were no age differences in recognition accuracy for repeated faces. For the N2, N400 and late positive complex (LPC), we analyzed the old/new effects (repetition 1 vs. new presentation) and the extended repetition effects (repetitions 1 through 5). Compared to older children, younger children exhibited larger frontocentral N2 and N400 old/new effects. For extended face repetitions, negativity of the N2 and N400 decreased in a linear fashion in both age groups. For the LPC, an ERP component thought to reflect recollection, no significant old/new or extended repetition effects were found. Employing the same face recognition paradigm in 20 adults (Study 2), we found a significant N400 old/new effect at lateral frontal sites and a significant LPC repetition effect at parietal sites, with LPC amplitudes increasing linearly with the number of repetitions. This study clearly demonstrates differential developmental courses for the N400 and LPC pertaining to recognition memory for faces. It is concluded that face recognition in children is mediated by early and probably more automatic than conscious recognition processes. In adults, the LPC extended repetition effect indicates that adult face recognition memory is related to a conscious and graded recollection process rather than to an automatic recognition process.

Developmental cognitive neuroscience of arithmetic: implications for learning and education

In this article, we review the brain and cognitive processes underlying the development of arithmetic skills. This review focuses primarily on the development of arithmetic skills in children, but it also summarizes relevant findings from adults for which a larger body of research currently exists. We integrate relevant findings and theories from experimental psychology and cognitive neuroscience. We describe the functional neuroanatomy of cognitive processes that influence and facilitate arithmetic skill development, including calculation, retrieval, strategy use, decision making, as well as working memory and attention. Building on recent findings from functional brain imaging studies, we describe the role of distributed brain regions in the development of mathematical skills. We highlight neurodevelopmental models that go beyond the parietal cortex role in basic number processing, in favor of multiple neural systems and pathways involved in mathematical information processing. From this viewpoint, we outline areas for future study that may help to bridge the gap between the cognitive neuroscience of arithmetic skill development and educational practice.

Infant febrile seizures: changes in declarative memory as revealed by event-related potentials

OBJECTIVE

According to a widespread opinion the vast majority of infant febrile seizures (IFS) are harmless. However, IFS are often associated with hippocampal sclerosis, which should lead to deficient episodic memory with spared context-free semantic memories. Although IFS represent the most common convulsive disorder in children, these consequences are rarely examined.

METHODS

We measured the hippocampal volume of 17 IFS children (7-9 years old) and an age-matched control group on the basis of MR images. Furthermore, we examined episodic and semantic memory performance with standardized neuropsychological tests. Two processes underlying recognition memory, namely familiarity and recollection, were assessed by means of event-related potentials (ERP).

RESULTS

The IFS children did not show a decreased hippocampus volume. Intelligence, working memory, semantic and episodic memory were intact. However, ERP indices of recognition memory subprocesses revealed deficits in recollection-based remembering that presumably relies on the integrity of the hippocampus, whereas familiarity-based remembering seemed to be intact.

CONCLUSIONS

Although hippocampus volume remains unaffected, IFS seems to induce functional changes in the MTL memory network, characterized by a compensation of recollection by familiarity-based remembering.

SIGNIFICANCE

This study significantly adds to the debate on the consequences of IFS by differentiating the impact on memory processing.

Age-related differences in brain activity during extended continuous word recognition in children

To examine the development of verbal recognition memory in primary-school children, 36 healthy younger children (8-9 years old) and 36 healthy older children (11-12 years old) participated in an ERP study with an extended continuous recognition task. Each word of a series of 30 words was shown randomly for six times interspersed with distracter words. The children were required to make old versus new decisions. The data analyses focused on old/new effects (repetition 1 vs. new word) and multiple repetition effects (repetitions 1 through 5) for the N1, P2, N400, and the late positive complex (LPC, 500-800 ms after stimulus onset). Younger children exhibited a strong P2 multiple repetition effect across left lateral regions, with P2 amplitudes increasing linearly with the number of word repetitions. Compared to younger children, older children exhibited a much stronger N400 old/new effect across parietal regions. Old/new and repetition effects for N1 and LPC were similar in both age groups. Correlational analysis showed that in older children, larger N400 old/new effects on the continuous recognition task were moderately associated with better verbal learning on an auditory verbal learning task. In both age groups, the gain in recognition accuracy over multiple repetitions correlated with the LPC repetition effect. The age differences in P2 repetition effects and N400 old/new effects suggest that in younger children whole-word orthographic representations are dependent on the strength of the memory trace and that lexical-semantic representations develop with age. The LPC results suggest that recollection plays a substantial role in recognition memory of both younger and older children.

Electrophysiological indices of memory for temporal order in early childhood: implications for the development of recollection

The ability to recall contextual details associated with an event begins to develop in the first year of life, yet adult levels of recall are not reached until early adolescence. Dual-process models of memory suggest that the distinct retrieval process that supports the recall of such contextual information is recollection. In the present investigation, we used both behavioral and electrophysiological measures to assess the development of memory for contextual details, as indexed by memory for temporal order, in early childhood. Results revealed age-related improvements in memory for temporal order despite similar levels of memory for the individual items themselves. Furthermore, this pattern of recall was associated with specific components in the electrophysiological response. Consistent with electrophysiological research in adults, distributed, positive-going activity late in the waveform was associated with increases in recall of contextual details and the development of recollective processes.

Updating P300: an integrative theory of P3a and P3b

The empirical and theoretical development of the P300 event-related brain potential (ERP) is reviewed by considering factors that contribute to its amplitude, latency, and general characteristics. The neuropsychological origins of the P3a and P3b subcomponents are detailed, and how target/standard discrimination difficulty modulates scalp topography is discussed. The neural loci of P3a and P3b generation are outlined, and a cognitive model is proffered: P3a originates from stimulus-driven frontal attention mechanisms during task processing, whereas P3b originates from temporal-parietal activity associated with attention and appears related to subsequent memory processing. Neurotransmitter actions associating P3a to frontal/dopaminergic and P3b to parietal/norepinephrine pathways are highlighted. Neuroinhibition is suggested as an overarching theoretical mechanism for P300, which is elicited when stimulus detection engages memory operations.

Updating P300: an integrative theory of P3a and P3b

The empirical and theoretical development of the P300 event-related brain potential (ERP) is reviewed by considering factors that contribute to its amplitude, latency, and general characteristics. The neuropsychological origins of the P3a and P3b subcomponents are detailed, and how target/standard discrimination difficulty modulates scalp topography is discussed. The neural loci of P3a and P3b generation are outlined, and a cognitive model is proffered: P3a originates from stimulus-driven frontal attention mechanisms during task processing, whereas P3b originates from temporal-parietal activity associated with attention and appears related to subsequent memory processing. Neurotransmitter actions associating P3a to frontal/dopaminergic and P3b to parietal/norepinephrine pathways are highlighted. Neuroinhibition is suggested as an overarching theoretical mechanism for P300, which is elicited when stimulus detection engages memory operations.

What people believe about memory

Two representative samples of adult Norwegians (n=2000) were asked a set of general and specific questions regarding their beliefs and opinions about human memory. The results indicate that on many questions, such as time of the earliest memories, inhibiting effects of collaboration, and memory for dramatic versus ordinary events, the views of the general public concurred with current research findings, and people in general had realistic views about their own memory performance. On other questions, such as the reliability of olfactory as compared with visual and auditory memory, the memory of small children in comparison with that of adults, the likelihood of repression of adult traumatic memories, and on more general questions such as the possibility of training memory and the capacity limitations of long-term memory, a large proportion of the participants expressed views that are less supported by scientific evidence. Implications of these findings are briefly discussed.

Neural correlates of memory development and learning: combining neuroimaging and behavioral measures to understand cognitive and developmental processes

This special issue includes 4 articles addressing the general theme of neural correlates of memory development and learning. Taken together, the articles represent a broad range of development, including infants, children, adolescents, and adults as participants. Each line of research examines relations between brain activity and cognitive functions using both physiological measures, event-related potentials or functional magnetic resonance imaging, and behavioral measures of memory and learning. This introduction sets the stage by briefly reviewing historical trends in memory development research, discussing major issues associated with neuroimaging research, and providing an integrated perspective of some specific contributions of the investigations included in this special issue, arguing that combining neuroimaging and behavioral measures advances research on memory development and learning in terms of understanding cognitive and developmental processes. The article concludes with a brief discussion of potential future directions for this type of research.

Making memories: a cross-sectional investigation of episodic memory encoding in childhood using FMRI

In adults, the neural substrate associated with encoding memories connected to a specific time and place include the prefrontal cortex and medial temporal lobe (MTL). Using functional magnetic resonance imaging, this research studied the developmental trajectory of this frontal-MTL system by comparing 7- and 8-year-old children to those who were 10 or older in conditions that promoted episodic encoding. In 1 condition, participants generated verbs from nouns heard; in another, they listened to short stories for comprehension. Regions in which brain activation predicted subsequent recognition memory performance were identified. These included the left prefrontal cortex, but not MTL, in the verb generation condition for both age groups. In the story comprehension condition, activation in left posterior MTL predicted subsequent memory performance in both age groups, and activation in left anterior MTL (including the hippocampus proper) and left prefrontal cortex predicted subsequent memory only for the older children. These results illustrate both similarities and differences in how brain systems interact in development to mediate the formation of episodic memories.

Age-related differences in familiarity and recollection: ERP evidence from a recognition memory study in children and young adults

Using event-related potentials (ERPs), we examined the relative contributions of familiarity and recollection to recognition memory for items and their study contexts in school-aged children and adults. Whereas adults were able to selectively accept target items and to reject familiar nontarget items in an exclusion task, this discrimination was more difficult for children, as was evident in the high false alarm rates to nontargets even when item memory was controlled for. The analysis of the adults' ERPs revealed more flexible and task-appropriate retrieval mechanisms, as was evident in the correlates of familiarity, recollection, and nontarget retrieval, as well as in postretrieval evaluation. In contrast, children's ERPs revealed a parietal old/new effect for targets taken as a putative correlate of recollection. These findings suggest that children rely predominantly on recollection during recognition judgments, even in the absence of efficient memory control processes. The latter processes enable adults to monitor and verify the retrieved information and to control nontarget retrieval in the service of adequate source memory performance.

Detection of youth at high risk for substance use disorders: a longitudinal study

This study extends prior research (D. Clark, J. Cornelius, L. Kirisci, & R. Tarter, 2005) by determining whether variation in the developmental trajectories of liability to substance use disorder (SUD) is contributed by neurobehavioral disinhibition, parental substance use involvement, and demographic variables. The sample, participants in a long-term prospective investigation, consisted of 351 boys, evaluated at ages 10-12, 12-14, 16, 19, and 22, whose parents either had SUD or no adult psychiatric disorder. Neurobehavioral disinhibition in childhood, in conjunction with parental lifetime substance use/SUD, place the child at very high risk for SUD by age 22 if psychosocial maladjustment progresses in severity in early adolescence. These results indicate that monitoring social adjustment during the transition from childhood to mid-adolescence is important for identifying youth at very high risk for succumbing to SUD by young adulthood.

Effects of repetition and configural changes on the development of face recognition processes

We investigated the effect of repetition on recognition of upright, inverted and contrast-reversed target faces in children from 8 to 15 years when engaged in a learning phase/test phase paradigm with target and distractor faces. Early (P1, N170) and late ERP components were analysed Children across age groups performed equally well, and were better at recognizing upright faces. However, teenagers and adults were equally accurate for all three face types. The neurophysiological responses to upright, inverted and negative faces matured until adulthood and showed different effects at different ages. P1 and N170 components were affected by face type at all ages, suggesting early configural disruption on encoding processes regardless of age. Frontal ERPs reflected the difficulty of processing these stimuli. Distinct repetition effects were seen at frontal, temporal frontal and parietal sites, suggesting differential involvement of these brain regions underlying working memory and recognition processes. Thus, a learning phase was sufficient (a) for 8-year-olds to perform as accurately as 15-year-olds and (b) to eliminate face type effects in teenagers and adults, but not in younger children.

Direct and mediated associations between P300 amplitude in childhood and substance use disorders outcome in young adulthood

BACKGROUND

Attenuated amplitude of the P300 wave has been frequently documented in youths at high risk for substance use disorders (SUDs). This investigation had two aims: 1) determine whether P300 amplitude in late childhood is a predictor of SUD outcome by age 19; and 2) evaluate whether neurobehavior disinhibition (ND) mediates this association.

METHODS

Boys (aged 10-12) were recruited through proband biological fathers with either a lifetime DSM-III-R diagnosis of SUD (N = 67) or no adult psychiatric disorder (N = 94). P300 amplitude was recorded during an auditory oddball task. Neurobehavior disinhibition was evaluated using tests of executive cognitive function, behavior under control, and emotion dysregulation. The relationship is assessed using multiple and logistic regressions.

RESULTS

Substance use disorder by age 19 was significantly predicted by P300 amplitude (odds ratio [OR] = .958; 95% confidence interval [CI] = .918-.999; Wald chi (2) = 3.992; df = 1; p = .045) and ND score (OR = 1.060; 95% CI = 1.023-1.098; Wald chi (2) = 10.267; df = 1; p = .0014) measured at age 10 to 12. P300 amplitude also significantly correlated with ND severity (beta = -.217; t = -2.412; df = 6,160; p = .017). Low P300 amplitudes were observed in children who succumbed to SUD by age 19.

CONCLUSIONS

These results indicate that ND mediates the association between attenuated P300 amplitude in childhood and SUD at age 19; however, P300 amplitude is not a specific childhood marker of SUD.

Association Among Parental Substance Use Disorder, P300 Amplitude, and Neurobehavioral Disinhibition in Preteen Boys at High Risk for Substance Use Disorder

The P300 amplitude of the event-related potential as a mediator of the association between parental substance use disorder (SUD) and child's neurobehavioral disinhibition was assessed. The P300 amplitude was recorded using an oddball task in sons of fathers having either lifetime SUD (n = 105) or no psychiatric disorder (n = 160). Neurobehavioral disinhibition was assessed using measures of affect regulation, behavior control, and executive cognitive function. Parental SUD and child's P300 amplitude accounted for, respectively, 16.6% and 16.8% of neurobehavioral disinhibition variance. Controlling for parental and child psychopathology, an association between parental SUD and child's P300 amplitude was not observed. It was concluded that the P300 amplitude does not mediate the association between parental SUD and child's neurobehavioral disinhibition.

Face recognition memory and configural processing: a developmental ERP study using upright, inverted, and contrast-reversed faces

The effects of configural changes on faces were investigated in children to determine their role in encoding and recognition processes. Upright, inverted, and contrast-reversed unfamiliar faces were presented in blocks in which one-third of the pictures repeated immediately or after one intervening face. Subjects (8-16 years) responded to repeated faces; event-related potentials were recorded throughout the procedure. Recognition improved steadily with age and all components studied showed age effects reflecting differing maturation processes occurring until adulthood. All children were affected by inversion and contrast-reversal, and face-type effects were seen on latencies and amplitudes of early components (P1 and N170), as well as on later frontal amplitudes. The "old-new" repetition effects (larger amplitude for repeated stimuli) were found at frontal sites and were similar across age groups and face types, suggesting a general working memory system comparably involved in all age groups. These data demonstrate that (1) there is quantitative development in face processing, (2) both face encoding and recognition improve with age, but (3) only encoding is affected by configural changes. The data also suggest a gradual tuning of face processing towards the upright orientation.

Digit span changes from puberty to old age under different levels of education

The goal of this study is to demonstrate the age-related changes in multimodality digit span under a research design in which level of education is controlled. Volunteer participants (n = 1183) were distributed over levels of age (13-98 years) and education (5-8, 9-11, and 12+ years). Digit span was measured through 11 scores of the Visual Aural Digit Span Test-Revised on aural or visual stimulation and oral or written response execution, thus allowing for the measurement of intra- and intersensory integration. The increase in digit span scores reversed to a decrease with early adulthood. The slope of the regression line was small but significant. A 4 x 3 x 2 multivariate analysis of variance showed a significant effect of age and education on a combined score comprising the 11 digit span scores. Differences of age and education were predicted by the auditory and visual input scores. The article discusses the cognitive correlates and the age-related changes in digit span from the biological standpoint.

Neurodevelopmental aspects of spatial navigation: a virtual reality fMRI study

Navigation in spatial contexts has been studied in diverse species, yielding insights into underlying neural mechanisms and their phylogenetic progression. Spatial navigation in humans is marked by age-related changes that may carry important implications for understanding cortical development. The emergence of "allocentric" processing, reflecting that ability to use viewer-independent spatial abstractions, represents an important developmental change. We used fMRI to map brain regions engaged during memory-guided navigation in a virtual reality environment in adolescents and adults. Blood oxygen level-dependent (BOLD) signal was monitored in eight adolescents and eight adults in a 1.5-T MRI scanner during three conditions: (1) memory-guided navigation (NAV); (2) arrow-guided navigation (ARROW); and (3) fixation (FIX). We quantified navigation ability during scanning and allocentric memory after scanning, based on subjects' ability to label a previously unseen, aerial view of the town. Adolescents and adults exhibited similar memory-guided navigation ability, but adults exhibited superior allocentric memory ability. Memory-guided navigation ability during scanning correlated with BOLD change between NAV/ARROWS in various regions, including a right frontal and right-anterior medial temporal lobe region. Age group and allocentric memory together explained significant variance in BOLD change in temporoparietal association cortex and the cerebellum, particularly in the left hemisphere. Consistent with developmental models, these findings relate maturation in the coding of spatial information to functional changes in a distributed, left-lateralized neural network.

Attention and selection in the growing child: views derived from developmental psychophysiology

Our understanding of developmental changes in attentional selection in the growing child has been advanced substantially by the results of (a relatively small number of) studies undertaken from a psychophysiological perspective. The basic outcome of these studies is that, in attentional filtering as well as selective set (the two basic paradigms in attention research), the processes necessary for attentional selection are in essence available even to the young child; however, the speed and efficiency of these processes tends to increase as the child grows into an adolescent. Under optimal conditions, filtering is performed at early stages of information processing, but less optimal stimulus characteristics and task requirements may induce a shift in the locus of selection to later processing stages for young children whereas older individuals are better able to preserve their early locus of selection. When early selection is constrained, young children are substantially more sensitive to the adverse effects of response competition. In selective set, sub-optimal conditions lead not so much to a shift in locus of selection processes, but to a shift in the age at which asymptote efficiency is attained. We have proposed hierarchical regression analysis as a useful technique to examine whether age-related differences in attention effects, as observed in specific ERP components and in RT, are reflections of an age effect on a single source of attentional selection or of separate sources that each contribute uniquely to the developmental trends seen in (attention effects on) RT. Re-analyses of existing data demonstrated that (again depending on task specifics) many but not all of the different component processes involved in attentional selection contributed unique variance to the age-related changes in attention effects.