Instrumental learning and cognitive flexibility processes are impaired in children exposed to early life stress

Children who experience severe early life stress show persistent deficits in many aspects of cognitive and social adaptation. Early stress might be associated with these broad changes in functioning because it impairs general learning mechanisms. To explore this possibility, we examined whether individuals who experienced abusive caregiving in childhood had difficulties with instrumental learning and/or cognitive flexibility as adolescents. Fifty‐three 14–17‐year‐old adolescents (31 exposed to high levels of childhood stress, 22 control) completed an fMRI task that required them to first learn associations in the environment and then update those pairings. Adolescents with histories of early life stress eventually learned to pair stimuli with both positive and negative outcomes, but did so more slowly than their peers. Furthermore, these stress‐exposed adolescents showed markedly impaired cognitive flexibility; they were less able than their peers to update those pairings when the contingencies changed. These learning problems were reflected in abnormal activity in learning‐ and attention‐related brain circuitry. Both altered patterns of learning and neural activation were associated with the severity of lifetime stress that the adolescents had experienced. Taken together, the results of this experiment suggest that basic learning processes are impaired in adolescents exposed to early life stress. These general learning mechanisms may help explain the emergence of social problems observed in these individuals.     

Effects of change in fatigue and depression on physical activity over time in relapsing-remitting multiple sclerosis

This prospective, observational study examined the effects of change in the symptoms of fatigue and depression on physical activity over time in persons with relapsing-remitting multiple sclerosis (RRMS). Adults with a confirmed diagnosis of RRMS completed a battery of questionnaires at baseline (n = 269) and six-month follow-up (n = 263). The data were analyzed using linear panel analysis and covariance modeling in Mplus 3.0. The panel model fit the data (χ(2) = 24.00, df = 15, p = 0.07, SRMR = 0.04, CFI = 0.98) and demonstrated that changes in both fatigue (path coefficient = -0.09) and depressive symptoms (path coefficient = -0.12) were significantly associated with residual change in physical activity. Such findings support the importance of fatigue and depression for predicting longitudinal changes in physical activity in adults with RRMS.     

Ovarian steroids enhance object recognition in naturally cycling and ovariectomized, hormone-primed rats

Learning and memory processes may be influenced by fluctuations in steroid hormones, such as estrogens and progestins. In this study, we have used an animal model to investigate the effects of endogenous fluctuations in ovarian steroids in intact female rats and effects of administration of ovarian steroids to ovariectomized rats for non-spatial, working memory using the object recognition task. Performance in this task relies on cortical and hippocampal function. As such, serum, cortical, and hippocampal concentrations of estradiol (E2), progesterone (P4), and P4's metabolite, 5alpha-pregnan-3alpha-ol-20-one (3alpha,5alpha-THP), were measured by radioimmunoassay. Experiment 1: Rats in behavioral estrus, compared to those in diestrus or estrus, spent a greater percentage of time exploring a novel object concomitant with increases in serum E2, P4, and 3alpha,5alpha-THP levels. Regression analyses revealed that there was a significant positive relationship between E2 levels in the hippocampus and 3alpha,5alpha-THP levels in the hippocampus and cortex and performance in this task. Experiment 2: Administration of E2 and/or P4 immediately post-training increased the percentage of time spent exploring the novel object and produced levels of E2, P4, and 3alpha,5alpha-THP akin to that of rats in behavioral estrus. Experiment 3: Post-training administration of selective estrogen receptor modulators, including 17beta-E2, propyl pyrazole triol, and diarylpropionitrile increased the percentage of time spent exploring the novel object compared to vehicle-administration. Experiment 4: Post-training P4 or 3alpha,5alpha-THP administration, compared to vehicle, increased the percentage of time spent exploring the novel object and produced P4 and/or 3alpha,5alpha-THP levels within the physiological range typically observed for rats in behavioral estrus. Experiment 5: If post-training administration of E2 and/or P4 was delayed one hour, no enhancement in object recognition was observed. Together, these results suggest that E2 and progestins can have mnemonic effects through actions in the cortex and/or hippocampus.     

ERbeta-selective SERMs produce mnemonic-enhancing effects in the inhibitory avoidance and water maze tasks

Estradiol (17beta-E2) can have mnemonic-enhancing effects; however, its mechanisms for these effects are not well-understood. The present studies examined effects of 17beta-E2 and selective estrogen receptor modulators (SERMs) on emotional and spatial memory of female, Long-Evans rats. First, whether or not 17beta-E2 has dose-dependent effects on inhibitory avoidance memory was investigated. Only the highest concentration of 17beta-E2 examined (10 microg), which produces physiological concentrations of E2, was effective at enhancing inhibitory avoidance memory (Experiment 1). Further studies were designed to elucidate whether SERMs may produce mnemonic effects similar to those of 17beta-E2. Compounds utilized were, the ERalpha-selective SERMs, propyl pyrazole triol (PPT) or 17alpha-E2, the ERbeta-specific SERMs, diarylpropionitrile (DPN) or 7,12-dihydrocoumestan (coumestrol), or vehicle (oil). Post-training administration of 10 microg 17beta-E2 or coumestrol enhanced memory in the inhibitory avoidance task compared to vehicle (Experiment 2). Memory in the water maze was enhanced by post-training administration of 17beta-E2, coumestrol, or DPN, compared to vehicle (Experiment 3). Co-administration of 17alpha-E2&DPN enhanced inhibitory avoidance memory similar to that seen following 17beta-E2 or coumestrol (Experiment 4). Administration of E2 2 h post-training was not effective at enhancing memory in the inhibitory avoidance or water maze tasks (Experiment 5). Lordosis of rats was enhanced by 17beta-E2, 17alpha-E2, or PPT, compared to vehicle (Experiment 6). These data suggest that: E2's actions at ERbeta, rather than ERalpha, may enhance spatial memory, E2's actions at ERalpha can facilitate sexual behavior, and that E2's actions involving both ERalpha and ERbeta may be important for emotional memory.     

Memory for the Events of Early Childhood

There has been much recent interest in the phenomenon of childhood amnesia, the difficulty most adults have in recalling at least the first 3 years of life. In contrast, it has been shown that infants 18 months of age or less can retain information over long periods. Although there is no agreed-upon explanation of this paradoxical phenomenon, there are proposed biological, cognitive, and social-cognitive explanations. Distinguishing among these accounts involves investigating both adults' memories for childhood events and the mnemonicabilities of young children. These studies may not only reveal the reason why our earliest years are shrouded from us as adults, but also shed light on the memory processes that allow us a rich representation of the remainder of our personal past.     

Memory and attention in combat-related post-traumatic stress disorder (PTSD)

Vietnam combat veterans assigned diagnoses of PTSD were compared on measures of attention/concentration, new learning, and memory with Army National Guard enlistees who reported no unusual traumatic events or stress-related symptoms. Results showed that PTSD veterans performed more poorly than the comparison sample on a measure of verbal learning, exhibiting less proficient cumulative acquisition across repeated exposures, greater sensitivity to proactive interference, and more perseverative errors. Veterans with PTSD diagnoses also evidenced impairments in word fluency and visual attention/tracking abilities. These preliminary findings suggest that diagnoses of chronic PTSD in combat veterans are associated with cognitive performance deficits, when comparisons are made with military troops judged to be free of stress-related psychopathology. Results are consistent with self-reported complaints of concentration and memory impairments among PTSD-diagnosed clinical samples, thus highlighting the need for continued investigation of the neuropsychologlcal sequelae of prolonged stress exposure.     

Best Practices for Counseling Clients Experiencing Poverty: A Grounded Theory

Poverty is a pressing sociopolitical issue in the United States and worldwide. Poverty experiences have a significant effect on one’s mental health and overall wellness. Therefore, the ability to effectively serve clients experiencing poverty is critically important to professional counselors. However, there are no empirical models for counseling clients experiencing poverty. The authors present the results of a constructivist grounded theory study in which 21 professional counselors who work with clients experiencing poverty were interviewed to identify best practices for working with this population. Five major best practices are identified: (a) awareness, (b) training, (c) knowledge, (d) skills, and (e) advocacy. Implications for professional counseling are included.     

Memories of early childhood: Qualities of the experience of recollection

Memories judged to be recollections were contrasted with memories known to be based on second-hand sources in order to investigate the phenomenological qualities that underlie the experience of recollection. Adults rated the qualities of their recollections of an early childhood experience. Their ratings were compared with ratings of the qualities of memories of a similar autobiographical experience where the information was known to derive from other sources. Reported recollections were rated higher than memories based on other sources for many qualities, including sensory and spatial detail, location, thoughts, feelings, completeness, event detail, and pictorial representation. Comparison of the ratings of memories dating from different ages suggests that a memory may be judged to be recollected even if only a subset of the qualities characterizing recollections are present. This provides partial support for and clarification of Rubin's multiple-systems model of autobiographical memory.