Amedeo D'Angiulli

Vividness of visual imagery and incidental recall of verbal cues, when phenomenological availability reflects long-term memory accessibility

The relationship between vivid visual mental images and unexpected recall (incidental recall) was replicated, refined, and extended. In Experiment 1, participants were asked to generate mental images from imagery-evoking verbal cues (controlled on several verbal properties) and then, on a trial-by-trial basis, rate the vividness of their images; 30 min later, participants were surprised with a task requiring free recall of the cues. Higher vividness ratings predicted better incidental recall of the cues than individual differences (whose effect was modest). Distributional analysis of image latencies through ex-Gaussian modeling showed an inverse relation between vividness and latency. However, recall was unrelated to image latency. The follow-up Experiment 2 showed that the processes underlying trial-by-trial vividness ratings are unrelated to the Vividness of Visual Imagery Questionnaire (VVIQ), as further supported by a meta-analysis of a randomly selected sample of relevant literature. The present findings suggest that vividness may act as an index of availability of long-term sensory traces, playing a non-epiphenomenal role in facilitating the access of those memories.

Children's Event-Related Potentials of Auditory Selective Attention Vary With Their Socioeconomic Status

Past research suggests a link between socioeconomic status (SES) and brain processes in children, but direct evidence from neuroimaging is scarce. The authors investigated the relationships among SES, performance, and the neural correlates of auditory selective attention, by comparing event-related potentials (ERPs) in lower- and higher-SES preadolescent children during a task in which they attended to two types of pure tones but ignored two other types. Our hypothesis was that, at comparable performance levels, higher-SES children ignore distracters (the unattended, irrelevant tones) while lower-SES children attend equally to distracters and to targets (the attended, relevant tones). The authors found that ERP waveform differences between attended and unattended tones (Nd, difference negativity) were significant in the higher-SES but not in the lower-SES group. However, the groups did not differ in reaction times or accuracy. Electroencephalographic power analysis revealed a differential pattern of theta activity concomitant with irrelevant tones for the two groups, indicating that although they performed similarly the children from these groups recruited different neural processes. Lower-SES children, the authors suggest, deployed supplementary resources to also attend to irrelevant information.

Exposure to severe urban air pollution influences cognitive outcomes, brain volume and systemic inflammation in clinically healthy children

Exposure to severe air pollution produces neuroinflammation and structural brain alterations in children. We tested whether patterns of brain growth, cognitive deficits and white matter hyperintensities (WMH) are associated with exposures to severe air pollution. Baseline and 1 year follow-up measurements of global and regional brain MRI volumes, cognitive abilities (Wechsler Intelligence Scale for Children-Revised, WISC-R), and serum inflammatory mediators were collected in 20 Mexico City (MC) children (10 with white matter hyperintensities, WMH(+), and 10 without, WMH(-)) and 10 matched controls (CTL) from a low polluted city. There were significant differences in white matter volumes between CTL and MC children - both WMH(+) and WMH(-) - in right parietal and bilateral temporal areas. Both WMH(-) and WMH(+) MC children showed progressive deficits, compared to CTL children, on the WISC-R Vocabulary and Digit Span subtests. The cognitive deficits in highly exposed children match the localization of the volumetric differences detected over the 1 year follow-up, since the deficits observed are consistent with impairment of parietal and temporal lobe functions. Regardless of the presence of prefrontal WMH, Mexico City children performed more poorly across a variety of cognitive tests, compared to CTL children, thus WMH(+) is likely only partially identifying underlying white matter pathology. Together these findings reveal that exposure to air pollution may perturb the trajectory of cerebral development and result in cognitive deficits during childhood.

Neuroinflammation, Hyperphosphorylated Tau, Diffuse Amyloid Plaques, and Down-Regulation of the Cellular Prion Protein in Air Pollution Exposed Children and Young Adults

Air pollution exposures have been linked to neuroinflammation and neuropathology. Autopsy samples of the frontal cortex from control (n = 8) and pollution-exposed (n = 35) children and young adults were analyzed by RT-PCR (n = 43) and microarray analysis (n = 12) for gene expression changes in oxidative stress, DNA damage signaling, NFκB signaling, inflammation, and neurodegeneration pathways. The effect of apolipoprotein E (APOE) genotype on the presence of protein aggregates associated with Alzheimers disease (AD) pathology was also explored. Exposed urbanites displayed differential (>2-fold) regulation of 134 genes. Forty percent exhibited tau hyperphosphorylation with pre-tangle material and 51% had amyloid-β (Aβ) diffuse plaques compared with 0% in controls. APOE4 carriers had greater hyperphosphorylated tau and diffuse Aβ plaques versus E3 carriers (Q = 7.82, p = 0.005). Upregulated gene network clusters included IL1, NFκB, TNF, IFN, and TLRs. A 15-fold frontal down-regulation of the prion-related protein (PrP(C)) was seen in highly exposed subjects. The down-regulation of the PrP(C) is critical given its important roles for neuroprotection, neurodegeneration, and mood disorder states. Elevation of indices of neuroinflammation and oxidative stress, down-regulation of the PrP(C) and AD-associated pathology are present in young megacity residents. The inducible regulation of gene expression suggests they are evolving different mechanisms in an attempt to cope with the constant state of inflammation and oxidative stress related to their environmental exposures. Together, these data support a role for air pollution in CNS damage and its impact upon the developing brain and the potential etiology of AD and mood disorders.

The development of reading in English and Italian in bilingual children

Canadian children (n = 81; 9–13 years) who spoke both English and Italian were administered phonological, reading, spelling, syntactic, and working memory tasks in both languages. There was a significant relationship between English and Italian across all phonological tasks. The relationship was less evident for syntactic skills and was generally absent for working memory measures. Analyses of phonological, syntactic, and memory processes based on levels of skill in English reading showed significantly better performance by skilled readers compared to less skilled readers; this was also true for the 11- to 13-year-olds compared to the 9- to 10-year-olds. Similar results were obtained as a function of levels of skill in Italian reading. On all Italian tasks, the bilingual children lagged behind monolingual children matched on age. However, less skilled and skilled bilingual Italian children had significantly higher scores than monolingual English–Canadian children (with comparable reading skills) on English tasks involving reading, spelling, syntactic awareness, and working memory. The results suggest that English–Italian interdependence is most clearly related to phonological processing, but it may influence other linguistic modules. In addition, exposure to a language with more predictable grapheme–phoneme correspondences, such as Italian, may enhance phonological skills in English.

Cognitive Functioning as Measured by the WISC-R: Do Children with Learning Disabilities Have Distinctive Patterns of Performance?.

Patterns of performance on the Wechsler Intelligence Scale for Children—Revised (WISC-R) have been proposed as useful tools for the identification of children with learning disabilities (LD). However, most of the studies of WISC-R patterns in children with LD have been plagued by the lack of a typically achieving comparison group, by failure to measure individual patterns, and by the lack of a precise definition of LD. In an attempt to address these flaws and to assess the presence of patterns of performance on the WISC-R, we examined data from 121 children with typical achievement (TA), 143 children with reading disabilities (RD), and 100 children with a specific arithmetic disability (AD), ages 6 to 16 years. The results indicated that the RD and AD groups had significantly lower scores than the TA group on all the Verbal IQ subtests. Many of the children with AD and RD showed a significant difference between Verbal and Performance IQ scores, but so did many of the typically achieving children. Although there were some children with LD who showed the predicted patterns, typically, 65% or more of the children with LD did not. Furthermore, a proportion of the TA group—generally not significantly smaller than that of the RD and AD groups—showed discrepancy patterns as well. Our results indicate that the patterns of performance on intelligence tests are not reliable enough for the diagnosis of LD in individual children. Therefore, it might be more profitable to base the detection of an individuals LD on patterns of achievement test scores.

White Matter Hyperintensities, Systemic Inflammation, Brain Growth, and Cognitive Functions in Children Exposed to Air Pollution

Air pollution exposures are linked to neuroinflammation and neuropathology in young urbanites. Forty percent of exposed children and young adults exhibit frontal tau hyperphosphorylation and 51% have amyloid-β diffuse plaques compared to 0% in low pollution controls. In older adults, white matter hyperintensities (WMH) are associated with cognitive deficits while inflammatory markers correlate with greater atrophy than expected for age. We investigated patterns of WMH, magnetic resonance imaging (MRI) volume growth, blood inflammatory mediators, and cognition in matched children from two urban cohorts: one severely and one minimally exposed to air pollution. Baseline and one year follow-up measurements of cognitive abilities, brain MRI volumes, and blood were collected in 20 Mexico City (MC) children (10 with WMH+, and 10 without WMH-) and 10 matched controls (WMH-). MC WMH- children display the profile of classical pro-inflammatory defensive responses: high interleukin 12, production of powerful pro-inflammatory cytokines, and low concentrations of key cytokines and chemokines associated with neuroprotection. MC WMH+ children exhibit a response involved in resolution of inflammation, immunoregulation, and tissue remodeling. The MC WMH+ group responded to the air pollution-associated brain volumetric alterations with white and grey matter volume increases in temporal, parietal, and frontal regions and better cognitive performance compared to MC WMH-. We conclude that complex modulation of cytokines and chemokines influences childrens central nervous system structural and volumetric responses and cognitive correlates resulting from environmental pollution exposures. Identification of biomarkers associating systemic inflammation to brain growth is critical for detecting children at higher risk for cognitive deficits and neurodegeneration, thereby warranting early implementation of neuroprotective measures.

Megacities air pollution problems: Mexico City Metropolitan Area critical issues on the central nervous system pediatric impact.

The chronic health effects associated with sustained exposures to high concentrations of air pollutants are an important issue for millions of megacity residents and millions more living in smaller urban and rural areas. Particulate matter (PM) and ozone (O3) concentrations close or above their respective air quality standards during the last 20 years affect 24 million people living in the Mexico City Metropolitan Area (MCMA). Herein we discuss PM and O3 trends in MCMA and their possible association with the observed central nervous system (CNS) effects in clinically healthy children. We argue that prenatal and postnatal sustained exposures to a natural environmental exposure chamber contribute to detrimental neural responses. The emerging picture for MCMA children shows systemic inflammation, immunodysregulation at both systemic and brain levels, oxidative stress, neuroinflammation, small blood vessel pathology, and an intrathecal inflammatory process, along with the early neuropathological hallmarks for Alzheimer and Parkinsons diseases. Exposed brains are briskly responding to their harmful environment and setting the bases for structural and volumetric changes, cognitive, olfactory, auditory and vestibular deficits and long term neurodegenerative consequences. We need to improve our understanding of the PM pediatric short and long term CNS impact through multidisciplinary research. Public health benefit can be achieved by integrating interventions that reduce fine PM levels and pediatric exposures and establishing preventative screening programs targeting pediatric populations that are most at risk. We fully expect that the health of 24 million residents is important and blocking pediatric air pollution research and hiding critical information that ought to be available to our population, health, education and social workers is not in the best interest of our children.

Schooling, Socioeconomic Context and Literacy Development

This longitudinal study examined the relationship between schooling, literacy development, and socioeconomic context, as reflected by a composite measure of socioeconomic status (SES). Reading, spelling, and phonological abilities were assessed from kindergarten to grade three in Canadian children in a school district with intensive literacy activities. In kindergarten, there were significant associations between SES and all the abilities assessed but these associations declined systematically to non‐significant levels by grade three. Risk and prevalence of reading failure also decreased with more schooling. The results suggest that the attenuation of the association between SES and literacy‐related skills, and the progressive reduction of the risk for reading failure, were positive outcomes associated with the literacy school program, especially in the early grades.

Decreases in Short Term Memory, IQ, and Altered Brain Metabolic Ratios in Urban Apolipoprotein ε4 Children Exposed to Air Pollution.

Childrens urban air pollution exposures result in systemic and brain inflammation and the early hallmarks of Alzheimers disease (AD). The apolipoprotein E (APOE) ε4 allele is the most prevalent genetic risk for AD. We assessed whether APOE in healthy children modulates cognition, olfaction, and metabolic brain indices. The Wechsler Intelligence Scale for Children (WISC-R) and the University of Pennsylvania Smell Identification Test were administered to 50 Mexico City Metropolitan Area children (13.4 ± 4.8 years, 28 APOE ε3 and 22 APOE ε4). N-acetylaspartate (NAA)/creatine (Cr), choline (Cho)/Cr, myo-inositol (mI)/Cr, and NAA/mI were calculated using proton magnetic resonance spectroscopy in the white matter of the frontal and parietal lobes, hippocampus, and pons. APOE ε4 versus ε3 children had a reduced NAA/Cr ratio in the right frontal white matter and decrements on attention, short-term memory, and below-average scores in Verbal and Full Scale IQ (>10 points). APOE modulated the group effects between WISC-R and left frontal and parietal white matter, and hippocampus metabolites. Soap was the predominantly failed odor in urban children and, in APOE ε4 versus ε3 carriers, strongly correlated with left hippocampus mI/Cr ratio. APOE modulates responses to air pollution in the developing brain. APOE ε4 carriers could have a higher risk of developing early AD if they reside in a polluted environment. APOE, cognition, and olfaction testing and targeted magnetic resonance spectroscopy may contribute to the assessment of urban children and their results could provide new paths toward the unprecedented opportunity for early neuroprotection and AD prevention.