Hypothalamic-Pituitary-Adrenal Reactivity to Acute Stress: an Investigation into the Roles of Perceived Stress and Family Resources.

Rurally situated African Americans suffer from chronic exposure to stress that may have a deleterious effect on health outcomes. Unfortunately, research on potential mechanisms that underlie health disparities affecting the African American community has received limited focus in the scientific literature. This study investigated the relationship between perceived stress, family resources, and cortisol reactivity to acute stress. A rural sample of African American emerging adults (N = 60) completed a battery of assessments, the Trier Social Stress Test (TSST), and provided four samples of salivary cortisol: prior to receiving TSST instructions, prior to conducting the speech task, immediately following the TSST, and 15-20 min following the TSST. As predicted, cortisol levels increased in response to a controlled laboratory inducement of acute stress. Moreover, diminished levels of family resources were associated with blunted cortisol reactivity to acute stress. Of note, higher levels of perceived stress over the past month and being male were independently associated with lower levels of cortisol at baseline. Lack of family resources had a blunting relationship on the hypothalamic-pituitary-adrenal axis reactivity. These findings provide biomarker support for the relationship between family resources-an indicator associated with social determinants of health-and stress physiology within a controlled laboratory experiment. Identifying mechanisms that work toward explanation of within-group differences in African American health disparities is both needed and informative for culturally informed prevention and intervention efforts.

Off-line sentence processing: what is involved in answering a comprehension probe?

The aim of this study was to better characterize the influence of the comprehension probe on syntax-related activation patterns observed in fMRI studies of sentence comprehension. In this study, sentence comprehension was assessed by presenting a true/false statement after each sentence. To disassociate the sentence reading from the comprehension probe activation, a 6-s delay was placed between these processing phases. Two factors were manipulated, one affected the sentence and the other affected the probe. The sentences were manipulated by varying their syntactic complexity; conjoined-active and object-relative sentences were examined. The comprehension probes asked whether one of the first two mentioned nouns in the preceding sentence performed the action of one of the two verbs. The probes were manipulated by varying the distance (number of intervening words) between the noun and verb within the sentence; there were three probe types: short distance, long distance, and false statements. The results, which focused on the processing taking place during the probe, showed that the distance manipulation resulted in significant differences in both behavioral and brain activation measures. This was particularly true of BA 44, which revealed an interaction between complexity and distance such that the complexity effect was all but eliminated for the long-distance condition. Additionally, we replicated our previous finding of syntactic complexity effects during the probe phase. Finally, post hoc analysis revealed that participants used two distinct strategies during sentence reading; significant effects of strategy use on both behavioral and brain activation data were observed.