Longitudinal assessment of mental health after a flood: roles of social support, hope, recovery stressors, and prior lifetime trauma.

OBJECTIVES: Severe weather events have mental health consequences for survivors that may change over time. We assessed post-flood mental health longitudinally in three groups of mostly middle-aged and older adults who varied in current and prior severe weather experiences. METHOD: Predictors of central interest were age, perceived social support, state hope (including agency and pathways), recovery stressors, and prior lifetime trauma. Criterion variables included symptoms of depression, post-traumatic stress disorder (PTSD), and worry. RESULTS: Analyses of variance yielded significant Disaster Exposure Group x Wave interactions for depression and PTSD symptoms. Those with flooded homes and properties had elevated symptoms at Wave 1 which were reduced at Wave 2. Older age was associated with fewer symptoms of depression, PTSD, and worry. Recovery stressors and lifetime trauma predicted more PTSD symptoms. Greater agency predicted less PTSD and depression symptoms, whereas pathways predicted less worry. CONCLUSION: These data show that mental health symptoms may decrease over time for those directly impacted by severe flooding. State hope appears to contribute to better mental health after exposure to a devastating flood. Implications for understanding the dynamic relationships among risk variables and positive factors that promote post-disaster mental health in the years after a flood are considered.

Religiosity and Social Support Predict Resilience in Older Adults After a Flood.

In this study, we examined religiosity and social support as predictors of resilience after a devastating flood. Three flood exposure groups of primarily middle-aged and older adults were compared: (1) non-flooded adults as controls, (2) once-flooded adults with structural damage to homes and property in the 2016 flood, and (3) twice-flooded adults who had relocated inland because of prior catastrophic losses in the 2005 Hurricanes Katrina and Rita and then flooded again in 2016. Resilience was assessed using the Connor-Davidson Resilience Scale (CD-RISC). Correlation analyses confirmed that older age was correlated with higher religiosity, charitable work done for others, and resilience. Regression analyses indicated that religious beliefs and coping, social support, and charitable work done for others were associated with higher levels of resilience, whereas flood damage was unrelated to resilience. Implications for current views on post-disaster adversity and resilience in later life are discussed.

High-fat diet induces an ovulatory defect associated with dysregulated endothelin-2 in mice.

High-fat diet (HFD) consumption in female rodents causes impaired estrous cyclicity, fewer pups per litter, and dysregulation of key ovulatory genes suggesting that HFD-induced subfertility may be due to ovulatory dysfunction. To test this hypothesis female mice were fed chow or HFD for 10 weeks at which point ovulation and ovarian gene expression of endothelin-2 (Edn2), a gene critical for ovulation, were assessed. After 10 weeks of HFD, both mice that remained lean and those that became obese had fewer ovulated oocytes than chow controls (P = 0.041, P = 0.0030, respectively). In chow controls, Edn2 was expressed as expected with basal levels during diestrus and proestrus, increased 11.6-fold during estrus, and decreased to basal levels during metestrus. In HFD mice, Edn2 was dysregulated across the entire estrous cycle as were other Edn2 system components (endothelin converting enzyme 1 (Ece-1), and the endothelin receptors (Ednra, Ednrb)). Interestingly, we found dysregulation of key ovarian steroidogenic genes after HFD. We also found that estradiol treatment in prepubertal mice increased Edn2 expression in the ovary (P = 0.030), suggesting that impaired steroidogenesis may be involved in the HFD-induced dysregulation of ovarian Edn2. In conclusion, HFD leads to ovulatory dysfunction regardless of the development of obesity, which appears to be mediated through dysregulation of ovarian Edn2 expression.

Multiyear Measurements on Δ17O of Stream Nitrate Indicate High Nitrate Production in a Temperate Forest.

Nitrification is a crucial step in ecosystem nitrogen (N) cycling, but scaling up from plot-based measurements of gross nitrification to catchments is difficult. Here, we employed a newly developed method in which the oxygen isotope anomaly (Δ17O) of nitrate (NO3-) is used as a natural tracer to quantify in situ catchment-scale gross nitrification rate (GNR) for a temperate forest from 2014 to 2017 in northeastern China. The annual GNR ranged from 71 to 120 kg N ha-1 yr-1 (average 94 ± 10 kg N ha-1 yr-1) over the 4 years in this forest. This result and high stream NO3- loss (4.2-8.9 kg N ha-1 yr-1) suggest that the forested catchment may have been N-saturated. At the catchment scale, the total N output of 10.7 kg N ha-1 yr-1, via leaching and gaseous losses, accounts for 56% of the N input from bulk precipitation (19.2 kg N ha-1 yr-1). This result indicates that the forested catchment is still retaining a large fraction of N from atmospheric deposition. Our study suggests that estimating in situ catchment-scale GNR over several years when combined with other conventional flux estimates can facilitate the understanding of N biogeochemical cycling and changes in the ecosystem N status.

Are individual differences in auditory processing related to auditory distraction by irrelevant sound? A replication study.

Irrelevant sounds can be very distracting, especially when trying to recall information according to its serial order. The irrelevant sound effect (ISE) has been studied in the literature for more than 40 years, yet many questions remain. One goal that has received little attention involves the discernment of a predictive factor, or individual difference characteristic, that would help to determine the size of the ISE. The current experiments were designed to replicate and extend prior work by Macken, Phelps, and Jones (Psychonomic Bulletin & Review, 16, 139-144, 2009), who demonstrated a significant predictive relationship between the size of the ISE and a type of auditory processing called global pattern matching. The authors also found a relationship between auditory processing involving deliberate recoding of sounds and serial order recall performance in silence. Across two experiments, this dissociation was not replicated. Additionally, the two types of auditory processing were not significantly correlated with each other. The lack of a clear pattern of findings replicating the Macken et al. (Psychonomic Bulletin & Review, 16, 139-144, 2009) study raises several questions regarding the need for future research on the characteristics of these auditory processing tasks, and the stability of the measurement of the ISE itself.

Musical training mediates the relation between working memory capacity and preference for musical complexity.

Previous research has examined the relationships among cognitive variables and musical training, but relatively less attention has addressed downstream effects of musical training on other psychological domains, such as aesthetic preference, and the potential impact of domain-general constructs, such as working memory. Accordingly, the present study sought to draw links between musical training, working memory capacity, and preference for musical complexity. Participants were assessed for their experience with musical training, their working-memory capacity, and their preference for musical complexity. Diverging from predictions based on vision research, our analyses revealed that musical training significantly mediated the association between working memory capacity and preference for music complexity. This significant mediation held even after a variety of sociodemographic variables (gender, education, socioeconomic status) were taken into account. Furthermore, the role of working memory capacity was domain general, such that the mediation was significant regardless of which measure of working memory capacity was used (tone, operation, or symmetry span). The current results develop a model of aesthetic preference that illuminates differences between vision and audition in terms of the multifaceted effects of complex skills training on cognition and affect. Moreover, they drive new work aimed at better understanding how domain-general constructs such as working memory capacity might interact with domain-specific cognition.

Unprocessed Atmospheric Nitrate in Waters of the Northern Forest Region in the U.S. and Canada.

Little is known about the regional extent and variability of nitrate from atmospheric deposition that is transported to streams without biological processing in forests. We measured water chemistry and isotopic tracers (δ18O and δ15N) of nitrate sources across the Northern Forest Region of the U.S. and Canada and reanalyzed data from other studies to determine when, where, and how unprocessed atmospheric nitrate was transported in catchments. These inputs were more widespread and numerous than commonly recognized, but with high spatial and temporal variability. Only 6 of 32 streams had high fractions (>20%) of unprocessed atmospheric nitrate during baseflow. Seventeen had high fractions during stormflow or snowmelt, which corresponded to large fractions in near-surface soil waters or groundwaters, but not deep groundwater. The remaining 10 streams occasionally had some (<20%) unprocessed atmospheric nitrate during stormflow or baseflow. Large, sporadic events may continue to be cryptic due to atmospheric deposition variation among storms and a near complete lack of monitoring for these events. A general lack of observance may bias perceptions of occurrence; sustained monitoring of chronic nitrogen pollution effects on forests with nitrate source apportionments may offer insights needed to advance the science as well as assess regulatory and management schemes.

Auditory distraction does more than disrupt rehearsal processes in children's serial recall.

As children mature, their ability to remember information improves. This improvement has been linked to changes in verbal control processes such as rehearsal. Rehearsal processes are thought to undergo a quantitative shift around 7 years of age; however, direct measurement of rehearsal is difficult. We investigated a measure of rehearsal ability in children and compared this measurement to serial recall performance in the presence of auditory distractors. Theories of auditory distraction effects in children rely upon a combination of attentionally based and serial-order-based processes (Elliott et al. in Journal of Memory and Language, 88, 39-50, 2016); the present work contributes to the understanding of auditory distraction effects by measuring both types of processes within one study. Children completed an individually adjusted serial-recall task with auditory distractors. To assess rehearsal, each child's proportionalized articulatory difference (PAD) score was calculated from performance on adaptive digit span tasks performed in quiet and under articulatory suppression (see also Jarrold & Citroën in Developmental Psychology, 49, 837-847, 2013). Attentional processes were measured in two ways: first, by using complex span tasks, and second, by children's vulnerability to disruption in the context of irrelevant sound. The results indicated that the rehearsal measure was significantly related to the auditory distraction effect, but this relation was isolated to the attentional-diversion component of the irrelevant-sound effect. The results provide preliminary evidence that children consume attentional resources during rehearsal. Moreover, irrelevant sound disrupts children's rehearsal not solely through automatic, obligatory conflict. Rather, irrelevant sound diverts children's attention, which prevents attentional resources from supporting rehearsal processes.

Memory Self-Efficacy and Beliefs about Memory and Aging in Oldest-Old Adults in the Louisiana Healthy Aging Study (LHAS).

Background/Study Context. Adaptation to normative age-related declines in memory is an important but understudied aspect of successful aging. The purpose of the present study was to shed new light on memory self-efficacy and beliefs about memory and aging as two integral aspects of adult cognition with relevance to successful aging. METHODS: Young (19 to 27 years) and community-dwelling older adults (60 to 94 years) from the Louisiana Healthy Aging Study (LHAS) completed an adapted Memory Functioning Questionnaire (MFQ) which includes a memory self-efficacy subscale, the Memory Controllability Inventory (MCI), and the Aging Concerns Scale (ACS). RESULTS: Nonagenarians' self-reported memory and beliefs about memory and aging were of central interest. We compared their responses to three younger reference groups to examine hypothesized differences in self-reported memory and beliefs about memory and aging in very late life. Results yielded age effects for most of the MFQ and MCI subscales demonstrating more positive subjective views about memory functioning and control over memory for the young adults. Correlation and regression analyses were conducted to isolate factors that may be associated with memory self-efficacy. Age, symptoms of depression, and memory control beliefs accounted for approximately half of the variance in memory self-efficacy ratings. CONCLUSION: These data indicate that although memory self-efficacy may be age sensitive, we detected no differences in subjective views across the three older groups. Implications for cognitive adaptability and successful aging are considered.

Efficacy of passive sampler collection for atmospheric NO2 isotopes under simulated environmental conditions.

RATIONALE: Nitrogen oxides or NOx (NOx = NO + NO2 ) play an important role in air quality, atmospheric chemistry, and climate. The isotopic compositions of anthropogenic and natural NO2 sources are wide-ranging, and they can be used to constrain sources of ambient NO2 and associated atmospheric deposition of nitrogen compounds. While passive sample collection of NO2 isotopes has been used in field studies to determine NOx source influences on atmospheric deposition, this approach has not been evaluated for accuracy or precision under different environmental conditions. METHODS: The efficacy of NO2 passive sampler collection for NO2 isotopes was evaluated under varied temperature and relative humidity (RH) conditions in a dynamic flux chamber. The precision and accuracy of the filter NO2 collection as nitrite (NO2- ) for isotopic analysis were determined using a reference NO2 gas tank and through inter-calibration with a modified EPA Method 7. The bacterial denitrifer method was used to convert 20 µM of collected NO2- or nitrate (NO3- ) into N2 O and was carried out on an Isoprime continuous flow isotope ratio mass spectrometer. RESULTS: δ15 N-NO2 values determined from passive NO2 collection, in conditions of 11-34 °C, 1-78% RH, have an overall accuracy and precision of ±2.1 ‰, and individual run precision of ±0.6 ‰. δ18 O-NO2 values obtained from passive NO2 sampler collection, under the same conditions, have an overall precision of ± 1.3 ‰. CONCLUSIONS: Suitable conditions for passive sampler collection of NO2 isotopes are in environments ranging from 11 to 34 °C and 1 to 78% RH. The passive NO2 isotope measurement technique provides an accurate method to determine variations in atmospheric δ15 N-NO2 values and a precise method for determining atmospheric δ18 O-NO2 values. The ability to measure NO2 isotopes over spatial gradients at the same temporal resolution provides a unique perspective on the extent and seasonality of fluctuations in atmospheric NO2 isotopic compositions. Copyright © 2017 John Wiley & Sons, Ltd.

Novel Method for Nitrogen Isotopic Analysis of Soil-Emitted Nitric Oxide.

The global inventory of NOx (NOx = NO + NO2) emissions is poorly constrained, with a large portion of the uncertainty attributed to soil NO emissions that result from soil abiotic and microbial processes. While natural abundance stable N isotopes (δ15N) in various soil N-containing compounds have proven to be a robust tracer of soil N cycling, soil δ15N-NO is rarely quantified due to the measurement difficulties. Here, we present a new method that collects soil-emitted NO through NO conversion to NO2 in excess ozone (O3) and subsequent NO2 collection in a 20% triethanolamine (TEA) solution as nitrite and nitrate for δ15N analysis using the denitrifier method. The precision and accuracy of the method were quantified through repeated collection of an analytical NO tank and intercalibration with a modified EPA NOx collection method. The results show that the efficiency of NO conversion to NO2 and subsequent NO2 collection in the TEA solution is >98% under a variety of controlled conditions. The method precision (1σ) and accuracy across the entire analytical procedure are ±1.1‰. We report the first analyses of soil δ15N-NO (-59.8‰ to -23.4‰) from wetting-induced NO pulses at both laboratory and field scales that have important implications for understanding soil NO dynamics.

The Influence of Marcellus Shale Extraction Emissions on Regionally Monitored Dry Reactive Nitrogen Deposition.

Emissions of nitrogen oxides (NOx) in the United States (U.S.) from large stationary sources, such as electric generating units, have decreased since 1995, driving decreases in nitrogen deposition. However, increasing NOx emissions from emerging industries, such as unconventional natural gas (UNG) extraction, could offset stationary source emission reductions in shale gas producing regions of the U.S. The Marcellus Shale in the northeastern U.S. has seen dramatic increases in the number of wells and associated natural gas production during the past 10 years. In this study, we examine the potential impacts of shale gas development on regional NOx emission inventories and dry deposition fluxes to Clean Air Status and Trends (CASTNET) sites in Pennsylvania and New York. Our results demonstrate that the current distribution of CASTNET sites is ineffective for monitoring the influence of Marcellus well NOx emissions on regional nitrogen deposition. Despite the fact that existing CASTNET sites are not influenced by UNG extraction activity, NOx emissions densities from shale gas extraction are substantial and are estimated to reach up to 21 kg NOx ha-1 year-1 in some regions. If these emissions deposit locally, UNG extraction activity could contribute to critical nitrogen load exceedances in areas of high well density.

Retrieval from long-term memory reduces working memory representations for visual features and their bindings.

The ability to remember feature bindings is an important measure of the ability to maintain objects in working memory (WM). In this study, we investigated whether both object- and feature-based representations are maintained in WM. Specifically, we tested the hypotheses that retaining a greater number of feature representations (i.e., both as individual features and bound representations) results in a more robust representation of individual features than of feature bindings, and that retrieving information from long-term memory (LTM) into WM would cause a greater disruption to feature bindings. In four experiments, we examined the effects of retrieving a word from LTM on shape and color-shape binding change detection performance. We found that binding changes were more difficult to detect than individual-feature changes overall, but that the cost of retrieving a word from LTM was the same for both individual-feature and binding changes.

Quantification of nitrate sources to an urban stream using dual nitrate isotopes.

Human-engineered landscapes and subsequent altered hydrology affect the fate and transport of reactive nitrogen, particularly in urban watersheds. In this study, we used dual-nitrate isotopes and mixing model analysis (δ(15)N and δ(18)O of NO3(-)) to quantify nitrogen inputs from two sources concentrated in urban systems, sewage and atmospheric deposition. Analysis was conducted on samples collected from Nine Mile Run (Pittsburgh, PA) including over two years of samples collected biweekly and samples collected through the hydrographs of four storm events. Mixing models incorporated uncertainties in the isotopic composition of potential nitrate sources and resolved the relative proportions of nitrate inputs from each source using Bayesian techniques. The results indicate that up to 94% of nitrate in streamwater originated from sewage sources during baseflow conditions. During storms, atmospheric deposition was a substantial nitrate source (∼ 34%) to total event-based nitrate loads, although sewage-derived nitrate remained the dominant source (66%). The potential influence of denitrification was considered by incorporating associated isotopic fractionations into mixing models; up to 19% of sewage-derived samples showed the isotopic effects of denitrification. This study quantitatively delineates proportions of nitrate from different sources to urban streamwater, while incorporating remaining uncertainties in source endmember compositions.

Characterizing the isotopic composition of atmospheric ammonia emission sources using passive samplers and a combined oxidation-bacterial denitrifier approach.

RATIONALE: Ammonia (NH3) emissions are a substantial source of nitrogen pollution to sensitive terrestrial, aquatic, and marine ecosystems and dependable quantification of NH3 sources is of growing importance due to recently observed increases in ammonium (NH4(+)) deposition rates. While determination of the nitrogen isotopic composition of NH3 (δ(15)N-NH3) can aid in the quantification of NH3 emission sources, existing methods have precluded a comprehensive assessment of δ(15)N-NH3 values from major emission sources. METHODS: We report an approach for the δ(15)N-NH4(+) analysis of low concentration NH4(+) samples that couples the bromate oxidation of NH4(+) to NO2(-) and the microbial denitrifier method for δ(15)N-NO2(-) analysis. This approach reduces the required sample mass by 50-fold relative to standard elemental analysis (EA) procedures, is capable of high throughput, and eliminates toxic chemicals used in a prior method for the analysis of low concentration samples. Using this approach, we report a comprehensive inventory of δ(15)N-NH3 values from major emission sources (including livestock operations, marine sources, vehicles, fertilized cornfields) collected using passive sampling devices. RESULTS: The δ(15)N-NH4(+) analysis approach developed has a standard deviation of ±0.7‰ and was used to analyze passively collected NH3 emissions with a wide range of ambient NH3 concentrations (0.2 to 165.6 µg/m(3)). The δ(15)N-NH3 values reveal that the NH3 emitted from volatilized livestock waste and fertilizer has relatively low δ(15)N values (-56 to -23‰), allowing it to be differentiated from NH3 emitted from fossil fuel sources that are characterized by relatively high δ(15)N values (-15 to +2‰). CONCLUSIONS: The isotopic source signatures presented in this emission inventory can be used as an additional tool in identifying NH3 emission sources and tracing their transport across localized landscapes and regions. The insight into the transport of NH3 emissions provided by isotopic investigation is an important step in devising strategies to reduce future NH3 emissions, a mounting concern for air quality scientists, epidemiologists, and policy-makers.

Constraining nitrogen inputs to urban streams from leaking sewers using inverse modeling: implications for dissolved inorganic nitrogen (DIN) retention in urban environments.

Leaking sewer infrastructure contributes nonpoint nitrogen pollution to groundwater and surface water in urban watersheds. However, these inputs are poorly quantified in watershed budgets, potentially underestimating pollutant loadings. In this study, we used inverse methods to constrain dissolved inorganic nitrogen (DIN) inputs from sewage to Nine Mile Run (NMR), an urban watershed (1570 ha) in Pittsburgh, Pennsylvania (USA) characterized by extensive impervious surface cover (38%). Water samples were collected biweekly over two years and intensive sampling was conducted during one summer storm. A nitrogen budget for the NMR watershed was constructed, ultimately inverted, and sewage DIN inputs constrained using Monte Carlo simulation. Results reveal substantial DIN contributions from sewage ranging from 6 to 14 kg ha-1 yr-1. When conservative estimates of DIN from sewage are included in input calculations, DIN retention in NMR is comparable to high rates observed in other suburban/urban nutrient budgets (84%). These results suggest a pervasive influence of leaking sewers during baseflow conditions and indicate that sewage-sourced DIN is not limited to sewer overflow events. Further, they highlight the importance of sewage inputs to DIN budgets in urban streams, particularly as sewer systems age across the U.S.

Deconfounding serial recall: Response timing and the overarching role of grouping.

We used the timing of serial recall in several situations to reveal important aspects of recall groupings that participants construct and the reasons those groupings occur. We examined the timing of responses in the recall of digit strings within two published experiments. Cowan, Saults, Elliott, and Moreno (2002) examined memory for nine-item lists in a way that deconfounded the presentation modality, input versus output serial position (using a varied starting point of recall), memory load from items not yet recalled (using whole vs. partial recall), and the presence or absence of the temporal grouping of the lists into triads. Accuracy was strikingly different in the two modalities, with grouping drastically changing recall of acoustic lists but with little difference between grouped versus ungrouped visual lists. Despite the modality difference in recall, the present timing results show that participants imposed a similar grouped structure in recall for both modalities. When errors were made, the original grouping structure still was maintained in the output timing. Cowan et al. (2005, Experiment 1) presented ungrouped acoustic lists of varying lengths in a span task. In this case, there was never a grouping structure presented to the participant and the accuracy data did not reveal evidence of grouping, but we show clear grouping in the timing structure. This grouping structure varied with both the list length and an individual's span. Timing in both experiments shows that a grouping structure is imposed on responses in a manner that is dependent on several factors not present in the stimuli. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Nitrogen isotopic composition of coal-fired power plant NOx: influence of emission controls and implications for global emission inventories.

Despite the potential use of δ(15)N as a tracer of NO(x) source contributions, prior documentation of δ(15)N of various NO(x) emission sources is exceedingly limited. This manuscript presents the first measurements of the nitrogen isotopic composition of NO(x) (δ(15)N-NO(x)) emitted from coal-fired power plants in the U.S. at typical operating conditions with and without the presence of selective catalytic reduction (SCR) and selective noncatalytic reduction (SNCR) technology. To accomplish this, a novel method for collection and isotopic analysis of coal-fired stack NO(x) emission samples was developed based on modifications of a historic U.S. EPA stack sampling method. At the power plants included in this study, large differences exist in the isotopic composition of NO(x) emitted with and without SCRs and SNCRs; further the isotopic composition of power plant NO(x) is higher than that of other measured NO(x) emission sources confirming its use as an environmental tracer. These findings indicate that gradual implementation of SCRs at power plants will result in an industry-wide increase in δ(15)N values of NO(x) and NO(y) oxidation products from this emission source.

Examining an Alternative Scoring Procedure for a Clinical Working Memory Measure.

The Digit Span test is a widely used working memory measure. However, when using standardized scoring procedures, previous studies have demonstrated inconsistent relationships between Digit Span subtests and working memory measures frequently used in cognitive psychology experiments. Partial scoring involves awarding credit for all digits recalled in the correct serial location, whereas traditional scoring involves only awarding credit for a trial if all digits are recalled in the correct serial location. The current study compared the traditional all-or-nothing scoring method and the partial scoring method on Digit Span with other working memory measures and with measures of general fluid intelligence. The results showed that when differences were found, partial scoring was associated with stronger relationships with Digit Span Backwards but weaker relationships with Digit Span Forward and Sequencing compared with traditional scoring. These results support previous findings identifying differences between the Digit Span subtests and the utility of examining traditional scoring procedures.

Lexical access speed and the development of phonological recoding during immediate serial recall.

A recent Registered Replication Report (RRR) of the development of verbal rehearsal during serial recall (Elliott et al., 2021) revealed that children verbalized at younger ages than previously thought (Flavell et al., 1966), but did not identify sources of individual differences. Here we use mediation analysis to reanalyze data from the 934 children ranging from 5 to 10 years old from the RRR for that purpose. From ages 5 to 7, the time taken for a child to label pictures (i.e. isolated naming speed) predicted the child's spontaneous use of labels during a visually-presented serial reconstruction task, despite no need for spoken responses. For 6- and 7-year-olds, isolated naming speed also predicted recall. The degree to which verbalization mediated the relation between isolated naming speed and recall changed across development. All relations dissipated by age 10. The same general pattern was observed in an exploratory analysis of delayed recall for which greater demands are placed on rehearsal for item maintenance. Overall, our findings suggest that spontaneous phonological recoding during a standard short-term memory task emerges around age 5, increases in efficiency during the early elementary school years, and is sufficiently automatic by age 10 to support immediate serial recall in most children. Moreover, the findings highlight the need to distinguish between phonological recoding and rehearsal in developmental studies of short-term memory.