Development is in the details: Event-related theta oscillations reveal children and adults verify multiplication facts differently.

When verifying the correctness of single-digit multiplication problems, children and adults show a robust ERP correctness effect thought to reflect similar cognitive processes across groups. Recent studies suggest that this effect is instead a modulation of the negative-going N400 component in children, reflecting access to semantic memory, and the positive-going P300 component in adults, reflecting stimulus categorization. However, the relative difference in ERP amplitude is the same for both components, more positive for correct than incorrect solutions, presenting a challenge to ascertaining the appropriate interpretation. Time-frequency analysis (TFA) of the N400/P300 window provides an objective approach to dissociating these effects. TFA measured from solution onset during single-digit multiplication verification revealed significant modulations of event-related as theta power (3-6 Hz) in both groups. Correct trials elicit less power in children (9-12 years) and more power in adults relative to incorrect trials. These findings are consistent with modulations of the N400 and P300, respectively, where opposite effects were predicted for spectral power. The ERP results further support a reinterpretation of the multiplication correctness effect. In contrast, TFA of the N400 effect elicited to a word-picture verification task revealed the same event-related theta effect in both groups, with increased power for mismatched than matched pictures. Together, these findings provide evidence for a developmental shift in cognitive processing specific to the multiplication task. Models of arithmetic should account for this overlooked difference in cognitive processing between children and adults.

When multiplying is meaningful in memory: Electrophysiological signature of the problem size effect in children.

Children are less fluent at verifying the answers to larger single-digit arithmetic problems compared with smaller ones. This problem size effect may reflect the structure of memory for arithmetic facts. In the current study, typically developing third to fifth graders judged the correctness of single-digit multiplication problems, presented as a sequence of three digits, that were either small (e.g., 4 3 12 vs. 4 3 16) or large (e.g., 8 7 56 vs. 8 7 64). We measured the N400, an index of access to semantic memory, along with accuracy and response time. The N400 was modulated by problem size only for correct solutions, with larger amplitude for large problems than for small problems. This suggests that only solutions that exist in memory (i.e., correct solutions) reflect a modulation of semantic access likely based on the relative frequency of encountering small versus large problems. The absence of an N400 problem size effect for incorrect solutions suggests that the behavioral problem size effects were not due to differences in initial access to memory but instead were due to a later stage of cognitive processing that was reflected in a post-N400 main effect of problem size. A second post-N400 main effect of correctness at occipital electrodes resembles the beginning of an adult-like brain response observed in prior studies. In sum, event-related brain potentials revealed different cognitive processes for correct and incorrect solutions. These results allude to a gradual transition to an adult-like brain response, from verifying multiplication problems using semantic memory to doing so using more automatic categorization.

Differential effect of sleep deprivation on place cell representations, sleep architecture, and memory in young and old mice.

Poor sleep quality is associated with age-related cognitive decline, and whether reversal of these alterations is possible is unknown. In this study, we report how sleep deprivation (SD) affects hippocampal representations, sleep patterns, and memory in young and old mice. After training in a hippocampus-dependent object-place recognition (OPR) task, control animals sleep ad libitum, although experimental animals undergo 5 h of SD, followed by recovery sleep. Young controls and old SD mice exhibit successful OPR memory, whereas young SD and old control mice are impaired. Successful performance is associated with two cellular phenotypes: (1) "context" cells, which remain stable throughout training and testing, and (2) "object configuration" cells, which remap when objects are introduced to the context and during testing. Additionally, effective memory correlates with spindle counts during non-rapid eye movement (NREM)/rapid eye movement (REM) sigma transitions. These results suggest SD may serve to ameliorate age-related memory deficits and allow hippocampal representations to adapt to changing environments.

Meaning to multiply: Electrophysiological evidence that children and adults treat multiplication facts differently.

Multiplication tables are typically memorized verbally, with fluent retrieval leading to better performance in advanced math. Arithmetic development is characterized by strategy shifts from procedural operations to direct fact retrieval, which would not necessitate access to the facts' conceptual meaning. This study tested this hypothesis using a combination of event related brain potentials (ERP) and behavioral measures with 3rd-5th grade children and young adults. Participants verified the solutions to simple multiplication problems (2 × 3 = 6 or = 7) and the semantic fit of word-picture pairs, separately. Children showed an N400 effect to multiplication solutions with larger (more negative) amplitude for incorrect than correct solutions, reflecting meaning-level processing. A similar ERP response was observed in the word-picture verification task, with larger negative amplitude for word-picture pairs that were semantically mismatched compared to matched. In contrast, adults showed a P300 response for correct solutions, suggesting that they treated these solutions as potential targets in over-rehearsed mathematical expressions. This P300 response was specific to math fact processing, as the word-picture verification task elicited a classic N400 in adults. These ERP findings reveal an overlooked developmental transition that occurs after fifth grade, and speak to theories of arithmetic that have been based primarily on adult data.

How do caregivers affect children's academic performance? Evidence from Primary Caregivers' Educational Attainment and Children's Performance on Standardized Assessments.

Children's performance on standardized testing are affected by a variety of external factors, such as access to resources, school environment, or primary caregiver's education. Educational inequalities, likewise, have a negative impact on the quality of education and access to resources, and impact student performance. Student outcomes and performance, hence, are multidimensional in that there are many factors that play a role in student success. For instance, previous research has shown that mother's educational attainment has an impact on their children's academic performance. By understanding the effects of primary caregivers' educational attainment on student achievement, policies can be created to promote equity in the education system. The goal of the present study is to understand the impacts of primary caregivers' educational attainment and language history on children's standardized assessment performance. We analyzed data from a large-scale study that collected demographic information (age, language background, socioeconomic status, primary caregivers' education), standardized assessment scores (math fluency, oral comprehension, working memory, phonological awareness, and vocabulary size), and performance (accuracy, response times) on a simple multiplication task. The study included a total of 176 children, and we hypothesized that children with highly educated primary caregivers were more likely to perform higher on academic assessments and the math task. Results showed that children with fathers as primary caregivers performed better on our measure of math fluency compared to children with mothers as primary caregivers. Additionally, the primary caregiver's educational attainment showed significance in performance on math fluency, oral comprehension, and math task accuracy in the "some college" and "graduate degree" category. Together, these findings suggest that primary caregivers' educational attainment can affect children's performance on standardized assessments, though future research should explore a broader population sample.

Bilingual children access multiplication facts from semantic memory equivalently across languages: Evidence from the N400.

Typically, bilinguals learn multiplication facts in only one instruction language. Consequently, these facts may be represented and/or accessed as language-specific memories, requiring a qualitatively different retrieval process in their other language. Indeed, behavioral studies reveal that bilinguals verify arithmetic facts faster and better in the language of learning. Here, event-related potentials (ERPs) were used as a window into the neurocognitive processes underlying this language bias in children. ERPs were recorded while bilingual children verified the correctness of multiplication solutions. Operands were presented as spoken number words in Spanish and English, separately. Although a language bias was revealed in behavior, both languages elicited the same ERP correctness effect, an N400, reflecting similar cognitive processes in both languages. This suggests that the source of the behavioral difference is not at the level of semantic access. Our findings highlight the flexibility of the bilingual brain, especially when both languages are learned early.

Eating high fat chow and the behavioral effects of direct-acting and indirect-acting dopamine receptor agonists in female rats.

Eating high fat chow increases the sensitivity of male rats to some behavioral effects of the direct-acting dopamine receptor agonist quinpirole; it is not known whether sensitivity to quinpirole is similarly enhanced in female rats eating high fat chow. Female Sprague-Dawley rats had free access to standard chow (5.7% fat) or either free or restricted access (i.e. body weight matched to rats eating standard chow) to high fat (34.3% fat) chow. Quinpirole (0.0032-0.32 mg/kg) produced hypothermia and a low frequency of yawning. Eating high fat chow produced insulin resistance without affecting quinpirole-induced yawning or hypothermia. Pretreatment with the dopamine D2 receptor antagonist L-741,626 failed to increase quinpirole-induced yawning, indicating that the low frequency of yawning was not due to enhanced D2 receptor sensitivity. Compared with younger (postnatal day 75), drug-naive female rats in a previous study, rats in the present study (postnatal day 275) were more sensitive to cocaine-elicited (1-17.8 mg/kg) locomotion and the development of sensitization across 5 weeks; however, eating high fat chow did not further enhance these effects. These results suggest that drug history and age might modulate the effects of diet on sensitivity to drugs acting on dopamine systems.