The rhinal cortex: 'gatekeeper' of the declarative memory system

Almost all studies probing neural activity underlying the declarative memory system in humans have investigated either memory encoding or retrieval. Here, however, we suggest integrating encoding and retrieval operations into a single operation executed by the rhinal cortex. The more familiar an item is, the less rhinal processing it requires and the less vigorously it is encoded into memory. Given the anatomical position and the functional properties of the rhinal cortex, this operation fulfills an essential task: it optimally allocates limited encoding resources away from familiar information and towards novel information. We propose a rhinal processing stage that optimizes the declarative memory system by fully integrating encoding and retrieval operations into a single 'gatekeeper' operation.     

Reading rates of stutterers and nonstutterers during silent and oral reading

The purpose of this study was to investigate the differences between the reading rates of stutterers and nonstutterers during both silent and oral reading of fluently spoken words. Ten adult stutterers and 14 nonstutterers were instructed to read two lists of words over four trials each. The first trial of either the first or the second list was a silent reading trial. All the other trials were oral reading trials. The word lists consisted of nouns with word lengths from two to five syllables. The dependent variables were the silent and oral reading times per word and per syllable. The major findings were that stutterers, as compared to nonstutterers, required longer reading times per word and per syllable during both silent and oral reading. These results indicate that stutterers differ from nonstutterers in the basic processing time for verbal material.     

Psychologists' attitudes toward aids

Abstract

Practicing psychologists in all areas of the country will see an increasing number of persons at risk for AIDS, or with AIDS-related illnesses. Previous research has shown that AIDS elicits negative reactions from the general public and from certain health care professionals. In the current study, a national sample of randomly selected practicing psychologists completed attitude measures after reading vignettes that described a male patient with either AIDS or leukemia who was either homosexual or heterosexual. Respondents evaluated the AIDS patient more negatively and reported less willingness to interact with him in a professional role or in casual social situations. It is important to develop training and continuing education programs to prepare psychologists to deal with persons affected by AIDS.     

Exploring the influence of encoding format on subsequent memory

Distinctive encoding is greatly influenced by gist-based processes and has been shown to suffer when highly similar items are presented in close succession. Thus, elucidating the mechanisms underlying how presentation format affects gist processing is essential in determining the factors that influence these encoding processes. The current study utilised multivariate partial least squares (PLS) analysis to identify encoding networks directly associated with retrieval performance in a blocked and intermixed presentation condition. Subsequent memory analysis for successfully encoded items indicated no significant differences between reaction time and retrieval performance and presentation format. Despite no significant behavioural differences, behaviour PLS revealed differences in brain–behaviour correlations and mean condition activity in brain regions associated with gist-based vs. distinctive encoding. Specifically, the intermixed format encouraged more distinctive encoding, showing increased activation of regions associated with strategy use and visual processing (e.g., frontal and visual cortices, respectively). Alternatively, the blocked format exhibited increased gist-based processes, accompanied by increased activity in the right inferior frontal gyrus. Together, results suggest that the sequence that information is presented during encoding affects the degree to which distinctive encoding is engaged. These findings extend our understanding of the Fuzzy Trace Theory and the role of presentation format on encoding processes.     

Contributions of the medial temporal lobe to declarative memory retrieval: manipulating the amount of contextual retrieval

We investigated how the hippocampus and its adjacent mediotemporal structures contribute to contextual and noncontextual declarative memory retrieval by manipulating the amount of contextual information across two levels of the same contextual dimension in a source memory task. A first analysis identified medial temporal lobe (MTL) substructures mediating either contextual or noncontextual retrieval. A linearly weighted analysis elucidated which MTL substructures show a gradually increasing neural activity, depending on the amount of contextual information retrieved. A hippocampal engagement was found during both levels of source memory but not during item memory retrieval. The anterior MTL including the perirhinal cortex was only engaged during item memory retrieval by an activity decrease. Only the posterior parahippocampal cortex showed an activation increasing with the amount of contextual information retrieved. If one assumes a roughly linear relationship between the blood-oxygenation level-dependent (BOLD) signal and the associated cognitive process, our results suggest that the posterior parahippocampal cortex is involved in contextual retrieval on the basis of memory strength while the hippocampus processes representations of item-context binding. The anterior MTL including perirhinal cortex seems to be particularly engaged in familiarity-based item recognition. If one assumes departure from linearity, however, our results can also be explained by one-dimensional modulation of memory strength.     

Psychosocial Issues in Families Affected by Maple Syrup Urine Disease

The primary aim of this study was to ascertain the psychosocial issues faced by families affected by maple syrup urine disease (MSUD). The psychosocial adjustment and quality of life of children with MSUD were also described. Participants included 55 families and their children (ages 5 to 18 years) and teachers. Measures included a MSUD Family Survey, the Behavior Assessment System for Children (BASC) and the Pediatric Quality of Life Inventory (PedsQL). Parents reported via the MSUD Family Survey that the greatest sources of stress were financial and emotional. Many parents reported difficulty interacting with the medical staff and with schools. On the BASC, half of the children fell within the average range in psychosocial adjustment, although there were elevations in scales measuring attention, hyperactivity, and learning problems. On the PedsQL, the mean quality of life scores were closer to children with cancer than to a healthy sample. Despite the emotional and financial burden, parents reported that MSUD has also had a positive influence on their lives, leading to a world-view that is more compassionate and caring.     

Relationship between Cattell’s 16PF and fluid and crystallized intelligence

The aim of the study was to explore the relationship between the five global factors and 16 dimensions of Cattell’s personality model and fluid and crystallized intelligence. A total of 105 third graders (45.7% males) of three high schools participated in the research. Fluid intelligence was measured by Raven’s Advanced Progressive Matrices and crystallized intelligence was measured by the Mill Hill Vocabulary Scale. Personality traits were measured by the Sixteen Personality Factor Questionnaire. Anxiety is correlated neither with fluid nor with crystallized intelligence. Extraversion and Self-Control are negatively correlated with fluid intelligence whereas Tough-Mindedness is positively correlated with it. Independence is positively correlated with crystallized intelligence and Tough-Mindedness is negatively correlated with it. Regression analysis reveals that all broad personality factors, except anxiety, are significant predictors of fluid intelligence. When combined together, these factors account for 25% of the variance of fluid intelligence scores. The regression model with crystallized intelligence as a criterion variable is not statistically significant. The study results are consistent with the Chamorro-Premuzic and Furnham’s (2005) two-level conceptual framework. Although using a different taxonomy of personality, the results are in accordance with the model’s presuppositions.     

Young Adults with MSUD and Their Transition to Adulthood: Psychosocial Issues

Maple Syrup Urine Disease (MSUD) is an autosomal recessive condition with an incidence of 1 in 185,000 births worldwide. Regardless of the type of MSUD, treatment includes immediate and lifelong dietary restriction of isoleucine, leucine and valine. There is little known about the psychosocial impact of MSUD on the developmental milestones of emerging adulthood. We used a qualitative case study approach to explore the human experiences of MSUD on young adults (n?=?8) and parents (n?=?8). All participants were administered a semi-structured, qualitative interview as well as quantitative measures. Six core themes emerged: 1) lifelong strain of dietary management; 2) social isolation from peers and impact on dating; 3) impact of MSUD on academics and employment; 4) medical experiences and transition to adult care; 5) impact on family functioning; and 6) positive effects and growth. The results of this investigation highlight and expand awareness of the psychological and social needs of young adults with MSUD. This study calls for a collaborative, multidisciplinary effort in the treatment of these patients and their families.     

Race/Ethnic Differences in Social Resources as Cognitive Risk and Protective Factors

Overall social network size, often the sum of common lifetime relationships, including children, family, and friends, has been linked to cognitive impairment and Alzheimer’s Disease. However, little research has examined the association between network size composition and cognitive function in middle-aged and older adults in the context of race/ethnicity. We investigated the associations between the number of close children, family, and friends independently with executive function (EF) and memory across a subsample of non-Hispanic Black, Hispanic, and non-Hispanic White participants who completed the Health and Retirement Study Harmonized Cognitive Assessment Protocol (N = 2,395). We found that network size composition was more closely linked to EF than memory and that these associations varied by race/ethnicity. Specifically, the strongest associations existed between EF and quadratic estimates of the number of close children of non-Hispanic Black participants, and number of close family members for Hispanic participants. Among Black participants, a curvilinear relationship indicated that two close children were associated with greater EF, while a smaller or larger number of close children were associated with lower EF. On the other hand, among Hispanic participants, higher EF was associated with fewer (0–1) and greater (4-5+) numbers of family member contacts. Overall, these results indicate that examining children, family, and friends independently may be more useful than the common practice of aggregation of overall network size, especially in the context of race/ethnicity.