Inflammation, depression, and anxiety related to recognition memory in young adults.

Previous research suggests that common modifiable health risk factors (e.g., depression, anxiety, metabolic illness, inflammation) may have an impact on memory. In the present study, we sought to investigate relationships between a number of these health risk factors and two components of recognition memory (recollection and familiarity). Data were analyzed for 96 healthy young adults between 17 and 25 years old. Recollection and familiarity were measured using an associative recognition procedure involving unitized and unrelated word pairs, and regression analyses were used to relate recognition memory performance to physical health (inflammation via plasma IL-6 levels, central obesity via waste-to-hip ratio, and heart rate variability) and mental health (depression via CESD-R, stress via PSS, and state and personality trait anxiety via STAI) measures of modifiable risk factors. Together, these health variables predicted an additional 19% of the variance in recollection beyond what was accounted for by familiarity, and 15% of the variance in familiarity beyond what was accounted for by recollection. These effects were primarily driven by inflammation, depression, and trait anxiety, which were each significant (p < .05) independent predictors of recognition. Higher levels of depression and inflammation were related to worse recollection yet better familiarity. Higher levels of trait anxiety were related to better recollection but were not related to familiarity. These findings demonstrate complex relationships between these modifiable health risk factors and recognition memory. Future longitudinal and cross-sectional research is needed to further explore these relationships and determine whether or not poor health causes these changes in recognition.

The Shared Etiology of Attentional Control and Anxiety: An Adolescent Twin Study.

We investigated the etiology of attentional control (AC) and four different anxiety symptom types (generalized, obsessive-compulsive, separation, and social) in an adolescent sample of over 400 twin pairs. Genetic factors contributed to 55% of the variance in AC and between 43 and 58% of the variance in anxiety. Negative phenotypic associations between AC and anxiety indicated that lower attentional ability is related to increased risk for all 4 anxiety categories. Genetic correlations between AC and anxiety phenotypes ranged from -.36 to -.47, with evidence of nonshared environmental covariance between AC and generalized and separation anxiety. Results suggest that AC is a phenotypic and genetic risk factor for anxiety in early adolescence, with somewhat differing levels of risk depending on symptomatology.

Aggressive Behaviors in Young Siblings: Associations with Executive Functions and Maternal Characteristics.

Aggressive behaviors in early childhood are associated with multiple undesirable outcomes, including juvenile delinquency, academic failure, and substance abuse. This investigation employed a family study design to examine child, mother and sibling predictors of early-emerging aggressive behaviors. These predictors included several indices of executive functioning within children, depression symptoms and education level of mothers, and inhibitory control (IC) of siblings. The sample consisted of 95 families (191 children; boys = 100) with at least two, typically developing children between 30 and 66 months of age (M(age) = 45.93 months, SD = 12.40). Measures included laboratory-assessed working memory and IC, parent-reported aggressive behaviors, as well as self-reported maternal depression symptoms and education. Results revealed that children showed substantial sibling similarity in aggressive behaviors. Using multilevel regression analyses, low child IC and greater maternal depression symptoms were associated with increased child aggressive behaviors. Child working memory, maternal education, and sibling IC did not uniquely predict child aggressive behaviors. Moderation analyses revealed an interaction between maternal depression symptoms and maternal education, such that the effect of depression symptoms on child aggressive behaviors was particularly evident amongst highly educated mothers. The current analysis moved beyond a main effects model of maternal depression and extended previous findings on the importance of child IC to aggressive behaviors by using a multiple-child-per-family framework. A promising direction for future research includes assessing whether efforts to increase child IC are successful in reducing child aggressive behaviors.

The effect of object processing in content-dependent source memory.

BACKGROUND: Previous studies have suggested that the study condition of an item influences how the item is encoded. However, it is still unclear whether subsequent source memory effects are dependent upon stimulus content when the item and context are unitized. The present fMRI study investigated the effect of encoding activity sensitive to stimulus content in source memory via unitization. In the scanner, participants were instructed to integrate a study item, an object in either a word or a picture form, with perceptual context into a single image. RESULTS: Subsequent source memory effects independent of stimulus content were identified in the left lateral frontal and parietal regions, bilateral fusiform areas, and the left perirhinal cortex extending to the anterior hippocampus. Content-dependent subsequent source memory effects were found only with words in the left medial frontal lobe, the ventral visual stream, and bilateral parahippocampal regions. Further, neural activity for source memory with words extensively overlapped with the region where pictures were preferentially processed than words, including the left mid-occipital cortex and the right parahippocampal cortex. CONCLUSIONS: These results indicate that words that were accurately remembered with correct contextual information were processed more like pictures mediated by integrated imagery operation, compared to words that were recognized with incorrect context. In contrast, such processing did not discriminate subsequent source memory with pictures. Taken together, these findings suggest that unitization supports source memory for both words and pictures and that the requirement of the study task interacts with the nature of stimulus content in unitized source encoding.

Neural activity supporting the formation of associative memory versus source memory.

The ability to form a new association with discontiguous elements constitutes the very crux of episodic memory. However, it is not fully understood whether different types of associations rely on common neural correlates for encoding associations. In the present study, we investigated whether the formation of associative memory (associations between items) and source memory (associations between an item and its context) recruits common neural activity during encoding, or whether each type of association requires different neural activity for subsequent memory. During study, participants were visually presented a list of object pairs in the scanner while the names of objects were simultaneously presented either in a male or female voice. Participants completed a post-scan recognition test for associative and source memories for object pairs and their contexts. Associative memory was predicted in the left inferior prefrontal cortex, the fusiform gyrus and the medial temporal lobe including both perirhinal and parahippocampal cortices and the posterior hippocampus. Encoding activity for source memory was identified in the right insula and the right anterior hippocampus. Further, neural activity in the right posterior hippocampus was recruited for successful formation of both associative and source memories. Collectively, these findings highlight the pivotal role of the hippocampus in successful encoding of associative and source memories and add more weight to the role of the perirhinal cortex in associative encoding of objects. The present findings have implications for roles of the medial temporal lobe sub-regions for successful formation of associative and source memories.