Brain working memory network indices as landmarks of intelligence.

Identifying the neural correlates of intelligence has long been a goal in neuroscience. Recently, the field of network neuroscience has attracted researchers' attention as a means for answering this question. In network neuroscience, the brain is considered as an integrated system whose systematic properties provide profound insights into health and behavioral outcomes.

A mixed-modeling framework for whole-brain dynamic network analysis.

The emerging area of dynamic brain network analysis has gained considerable attention in recent years. However, development of multivariate statistical frameworks that allow for examining the associations between phenotypic traits and dynamic patterns of system-level properties of the brain, and drawing statistical inference about such associations, has largely lagged behind. To address this need we developed a mixed-modeling framework that allows for assessing the relationship between any desired phenotype and dynamic patterns of whole-brain connectivity and topology.

Effects of an Allostatic Closed-Loop Neurotechnology (HIRREM) on Brain Functional Connectivity Laterality in Military-Related Traumatic Stress.

Background And Purpose: Brain asymmetries are reported in posttraumatic stress disorder, but many aspects of laterality and traumatic stress remain underexplored. This study explores lateralization changes in resting state brain network functional connectivity in a cohort with symptoms of military-related traumatic stress, associated with use of a closed-loop neurotechnology, HIRREM.

Methods: Eighteen participants (17 males, mean age 41 years [SD = 7]) received 19.

Graph-Theoretical Study of Functional Changes Associated with the Iowa Gambling Task.

The primary aim of this study was to examine changes in functional brain network organization from rest to the Iowa Gambling Task (IGT) using a graph-theoretical approach. Although many functional neuroimaging studies have examined task-based activations in complex-decision making tasks, changes in functional network organization during this task remain unexplored. This study used a repeated-measures approach to examine changes in functional network organization across multiple sessions of resting-state and IGT scans.

Changes in brain network efficiency and working memory performance in aging.

Working memory is a complex psychological construct referring to the temporary storage and active processing of information. We used functional connectivity brain network metrics quantifying local and global efficiency of information transfer for predicting individual variability in working memory performance on an n-back task in both young (n = 14) and older (n = 15) adults. Individual differences in both local and global efficiency during the working memory task were significant predictors of working memory performance in addition to age (and an interaction between age and global efficiency).

Changes in global and regional modularity associated with increasing working memory load.

Using graph theory measures common to complex network analyses of neuroimaging data, the objective of this study was to explore the effects of increasing working memory processing load on functional brain network topology in a cohort of young adults. Measures of modularity in complex brain networks quantify how well a network is organized into densely interconnected communities. We investigated changes in both the large-scale modular organization of the functional brain network as a whole and regional changes in modular organization as demands on working memory increased from n = 1 to n = 2 on the standard n-back task.

Intraindividual variability in domain-specific cognition and risk of mild cognitive impairment and dementia.

Intraindividual variability among cognitive domains may predict dementia independently of interindividual differences in cognition. A multidomain cognitive battery was administered to 2305 older adult women (mean age 74 years) enrolled in an ancillary study of the Women's Health Initiative. Women were evaluated annually for probable dementia and mild cognitive impairment (MCI) for an average of 5.

Stability of whole brain and regional network topology within and between resting and cognitive states.

Background: Graph-theory based analyses of resting state functional Magnetic Resonance Imaging (fMRI) data have been used to map the network organization of the brain. While numerous analyses of resting state brain organization exist, many questions remain unexplored. The present study examines the stability of findings based on this approach over repeated resting state and working memory state sessions within the same individuals.

The locus of the benefits of repetition-lag memory training.

The repetition-lag training procedure developed by Jennings and Jacoby (2003 , Neuropsychological Rehabilitation, 14, 417) has been shown to improve older adults' performance in the recognition memory task used for training, and to improve performance in a variety of other memory and executive function tasks ( Jennings, Webster, Kleykamp, & Dagenbach, 2005 , Aging, Neuropsychology, and Cognition, 12, 278). The present study examined the effects of concurrent interference tasks during the study or test phases of training to localize the source of gains. Overall, the results suggest that training is resilient and resistant to interference, but also that the processes used during the test phases of training are more important to the gains seen in the primary task and in the transfer tasks than those used in the study phases.

Designing clinical trials for assessing the effects of cognitive training and physical activity interventions on cognitive outcomes: the Seniors Health and Activity Research Program Pilot (SHARP-P) study, a randomized controlled trial.

Background: The efficacy of non-pharmacological intervention approaches such as physical activity, strength, and cognitive training for improving brain health has not been established. Before definitive trials are mounted, important design questions on participation/adherence, training and interventions effects must be answered to more fully inform a full-scale trial.

Methods: SHARP-P was a single-blinded randomized controlled pilot trial of a 4-month physical activity training intervention (PA) and/or cognitive training intervention (CT) in a 2 × 2 factorial design with a health education control condition in 73 community-dwelling persons, aged 70-85 years, who were at risk for cognitive decline but did not have mild cognitive impairment.

Telephone interview for cognitive status (TICS) screening for clinical trials of physical activity and cognitive training: the seniors health and activity research program pilot (SHARP-P) study.

Objective: To examine the performance of the Telephone Interview for Cognitive Status (TICS) for identifying participants appropriate for trials of physical activity and cognitive training interventions.

Methods: Volunteers (N=343), ages 70-85 years, who were being recruited for a pilot clinical trial on approaches to prevent cognitive decline, were administered TICS and required to score ≥ 31 prior to an invitation to attend clinic-based assessments. The frequencies of contraindications for physical activity and cognitive training interventions were tallied for individuals grouped by TICS scores.

Age-related changes and the attention network task: an examination of alerting, orienting, and executive function.

The effects of aging on alerting, orienting, and executive function were examined with the use of the Attention Network Task, which combines the Posner spatial cuing task and the Eriksen flanker task into a single procedure. We found that older adults showed significantly less alerting than young adults in response to a warning cue, although there were no age differences in orienting or executive function once processing speed was taken into account. We suggest that age differences in alerting may depend in part upon the presentation duration or persistence of the warning cue.

Manipulating noise frequencies alters hemispheric contributions to decision making.

Participants listened to the Asian disease problem framed in terms of either gains or losses and chose between two plans to combat the disease. All participants heard the problem embedded in other sounds; for some it was the relatively lower-frequency information, and for others it was the relatively higher-frequency information. The classic framing effect appeared only for those participants for whom the problem was the relatively lower-frequency information (p<.

Recollection training and transfer effects in older adults: successful use of a repetition-lag procedure.

We examined an approach aimed at training consciously-controlled recollection, introduced by Jennings and Jacoby (2003) , for its ability to replicate and generalize. A continuous recognition task, requiring recollection to identify the occurrence of repeated items over gradually increasing lag intervals (number of intervening items between the first and second presentation of a repeated word), was given to a group of older adults twice a week for three weeks. Pre-and-post training performance was assessed on multiple measures and compared with a recognition practice and no contact control group.

Patterns of impaired verbal, spatial, and object working memory after thalamic lesions.

Working memory processes in six individuals with isolated thalamic lesions were assessed. Participants were given a verbal, spatial, and object n-back task, each at three levels of task load (1-back, 2-back, and 3-back). Relative to a control group, the patients were impaired on the verbal and spatial n-back tasks, and possibly on the object n-back task as well.