Relationships Between Dietary Intake and Weight-Related Experiential Avoidance Following Behavioral Weight-Loss Treatment.

BACKGROUND: Interventions targeting weight-related experiential avoidance (EA) and disinhibited eating (DE) may also improve diet quality. Participants with overweight/obesity and DE who recently completed a behavioral weight-loss program were randomized to receive acceptance and commitment therapy or continued behavioral weight-loss treatment. In this secondary analysis, we explored (1) change in diet quality from baseline to 6-month follow-up (FU) and (2) whether weight-related EA at baseline and (3) change in weight-related EA during treatment were related to change in diet quality from baseline to FU. METHOD: Veterans (N = 68) completed food frequency questionnaires at baseline and FU, which were used to generate diet quality scores on the healthy eating index-15 (HEI-15). Weight-related EA was assessed using the Acceptance and Action Questionnaire for Weight-Related Difficulties-Revised (AAQW-R) at baseline, post-treatment, and FU. Aims were examined with mixed ANOVA analyses. RESULTS: Across both treatment groups, HEI-15 scores declined from baseline to FU. Women's HEI-15 decreased by about 5 times that of men. Baseline AAWQ-R was negatively associated with change in HEI-15. Neither AAWQ-R at post-treatment nor change in AAQW-R from baseline to post-treatment was significantly associated with change in HEI-15 at FU. CONCLUSIONS: Greater weight-related EA at baseline was associated with lower diet quality at FU, but change in weight-related EA during treatment did not predict change in diet quality at FU. Interventions targeting DE and weight-loss may require specific components to improve and sustain healthy dietary intake in Veterans with obesity and DE.

Effects of 42 hr of total sleep deprivation on component processes of verbal working memory.

The current investigation examined changes in working memory (WM) component processes following total sleep deprivation (TSD) in a sample of healthy young persons. Forty subjects were administered a verbal form of a continuous recognition test (CRT) before and after 42 hr of TSD. Parameters of a computational model of the CRT reflecting attention, WM span, and rate of episodic memory encoding were estimated for each individual. Subjects made more errors on the test following sleep deprivation. Analysis of model parameters revealed statistically independent declines in both the attention and WM span parameters, with a larger effect observed for the decline in WM span. Examination of individual profiles suggested that the effects of TSD on verbal WM component processes vary from person to person. Declines in global verbal WM functioning appear to be primarily driven by reduced WM span and attention; however, these effects may be individual-specific. Further applications of the computational model for examining WM component processes with sleep deprivation and other clinical populations are discussed.

Increasing task difficulty facilitates the cerebral compensatory response to total sleep deprivation.

STUDY OBJECTIVES: To test the role of task difficulty in the cerebral compensatory response after total sleep deprivation (TSD). DESIGN: Subjects performed a modified version of Baddeley's logical reasoning task while undergoing functional magnetic resonance imaging twice: once after normal sleep and once following 35 hours of TSD. The task was modified to parametrically manipulate task difficulty. SETTING: Inpatient General Clinical Research Center and outpatient functional magnetic resonance imaging center. PATIENTS OR PARTICIPANTS: 16 young adults (7 women; mean age, 27.6 +/- 6.1 years; education, 15.4 +/- 1.8 years) were included in the final analyses. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Behaviorally, subjects performed the same after TSD as while well rested. Neuroimaging data revealed a linear increase in cerebral response with a linear increase in task demands in several brain regions after normal sleep. Even stronger linear responses were found after TSD in several brain regions, including bilateral inferior parietal lobes, bilateral temporal cortex, and left inferior and dorsolateral prefrontal cortex. CONCLUSIONS: Task difficulty facilitates the cerebral compensatory response observed following TSD. Compensation manifests as both new regions that did not show significant responses to task demands in the well-rested condition, as well as stronger responses within regions typically underlying task performance. The possible significance of these 2 types of responses should be explored further, as should the importance of the parietal lobes for cognitive performance after TSD.

Brain regions involved in simple and complex grammatical transformations.

Grammatical transformation is a verbal reasoning task requiring judging the veracity of statements describing the spatial order of letter sets. We studied 18 adults with FMRI while they performed grammatical transformations of varying complexity levels (2-letter, 3-letter, and 4-letter sentences). Brain regions activated by 2-letter sentences included the visuospatial processing regions of the bilateral parietal lobes and the frontal operculum. A linear increase in sentence complexity engaged dorsolateral and ventrolateral prefrontal cortex as well as significantly increased activation within 2LTR areas. These data provide evidence that grammatical transformation reasoning relies primarily on the posterior visuospatial working memory system and need not necessarily engage the prefrontal cortex. Increasing the complexity of grammatical transformation, though, activates prefrontal cortex.

Age-Related Influences of Prior Sleep on Brain Activation during Verbal Encoding.

Disrupted sleep is more common in older adults (OLD) than younger adults (YOUNG), often co-morbid with other conditions. How these sleep disturbances affect cognitive performance is an area of active study. We examined whether brain activation during verbal encoding correlates with sleep quantity and quality the night before testing in a group of healthy OLD and YOUNG. Twenty-seven OLD (ages 59-82) and 27 YOUNG (ages 19-36) underwent one night of standard polysomnography. Twelve hours post-awakening, subjects performed a verbal encoding task while undergoing functional magnetic resonance imaging. Analyses examined the group (OLD vs. YOUNG) by prior sleep quantity (total sleep time, TST) or quality (sleep efficiency, SE) interaction on cerebral activation, controlling for performance. Longer TST promoted higher levels of activation in the bilateral anterior parahippocampal in OLD and lower activation levels in the left anterior parahippocampus in YOUNG. Greater SE promoted higher activation levels in the left posterior parahippocampus and right inferior frontal gyrus in YOUNG, but not in OLD. The roles of these brain regions in verbal encoding suggest, in OLD, longer sleep duration may be linked to the ability to engage in functional compensation during cognitive challenges. By contrast, in YOUNG, shorter sleep duration may necessitate functional compensation to maintain cognitive performance, similar to what is seen following acute sleep deprivation. Additionally, in YOUNG, better sleep quality may improve semantic retrieval processes, thereby aiding encoding.