Urban African-American males' perceptions of condom use, gender and power, and HIV/STD prevention program

The overall goal of the research project was to develop, administer and assess a brief male-focused condom promotion program for inner-city young adult African-American males. To achieve that goal, we conducted a formative study consisting of both quantitative and qualitative research methods. For the qualitative component, which was guided by the relevant tenets of the social cognitive theory and the stages of change model, a series of focus group discussions was conducted among the target population based upon a thematic topic guide that covered three broad areas: young men's perceptions of condom use relative to pregnancy and HIV/sexually transmitted disease (STD) prevention, gender-based issues surrounding condom use, and potential guidelines for the development of customized condom promotion programs. Those focus group discussions were audiotaped and the transcribed data summarized and analyzed based on those thematic topics. The findings revealed that respondents were more likely to assume that they know the risk behaviors of their sexual partners, more likely to consider pregnancy as a socially desirable outcome, more likely to control condom use within relationship dynamics and sexual contexts, and also more likely to provide suggestions on suitable components for program development. The implications and limitations of those findings from this qualitative component of the project are herein described, including potential recommendations for program development.     

Partial recovery from amnesia following bilateral surgical fornix transection is correlated with cortical plasticity

We report a case of an interventricular ependymoma which was surgically removed but also required bilateral transection of the fornices resulting in memory impairment which gradually improved. Functional MR images using a memory paradigm showed that recovery correlated with cortical plasticity involving activation of the orbitofrontal cortex and the middle temporal gyrus.     

Mine and me: exploring the neural basis of object ownership

Previous research has shown that encoding information in the context of self-evaluation leads to memory enhancement, supported by activation in ventromedial pFC. Recent evidence suggests that similar self-memory advantages can be obtained under nonevaluative encoding conditions, such as when object ownership is used to evoke self-reference. Using fMRI, the current study explored the neural correlates of object ownership. During scanning, participants sorted everyday objects into self-owned or other-owned categories. Replicating previous research, a significant self-memory advantage for the objects was observed (i.e., self-owned > other-owned). In addition, encoding self-owned items was associated with unique activation in posterior dorsomedial pFC (dMPFC), left insula, and bilateral supramarginal gyri (SMG). Subsequent analysis showed that activation in a subset of these regions (dMPFC and left SMG) correlated with the magnitude of the self-memory advantage. Analysis of the time-to-peak data suggested a temporal model for processing ownership in which initial activation of dMPFC spreads to SMG and insula. These results indicate that a self-memory advantage can be elicited by object ownership and that this effect is underpinned by activity in a neural network that supports attentional, reward, and motor processing.     

Cortical and subcortical mechanisms at the core of imitation

Imitation is thought to require a perception-action matching process that utilizes the "mirror neuron" system, but other cognitive functions such as error detection may also be required for even simple imitation. We sought to explore the core neural substrate of imitation by examining the imitation of simple finger actions using fMRI. Participants observed one of two actions and were instructed to imitate the action they observed, or to perform the alternative non-matching action. The contrast between imitation and non-matching actions was associated with activation in areas previously associated with imitation and "mirror neuron" functioning, including insula, intraparietal sulcus, dorsal premotor cortex, and superior temporal gyrus. Imitation was also specifically associated with activity in areas of prefrontal cortex, lateral orbitofrontal cortex (OFC), amygdala, red nucleus, thalamus, hippocampus, and substantia nigra. We suggest that lateral OFC responds to action-perception mismatch and other clusters reflect working memory, motor planning, associative learning, and visuo-motor integration of goal-directed action. Although computational models have predicted integration of these functions to enable imitation, their specific brain bases have not previously been identified. Together they offer a potentially powerful means through which matching one's actions to those of others can lead to behavioral modification and development.     

Age-associated sex and asymmetry differentiation in hemispheric and lobar cortical ribbon complexity across adulthood: A UK Biobank imaging study

Cortical morphology changes with ageing and age-related neurodegenerative diseases. Previous studies suggest that the age effect is more pronounced in the frontal lobe. However, our knowledge of structural complexity changes in male and female brains is still limited. We measured cortical ribbon complexity through fractal dimension (FD) analysis at the hemisphere and lobe level in 7010 individuals from the UK Biobank imaging cohort to study age-related sex differences (3332 males, age ranged 45–79 years). FD decreases significantly with age and sexual dimorphism exists. With correction for brain size, females showed higher complexity in the left hemisphere and left and right parietal lobes whereas males showed higher complexity in the right temporal and left and right occipital lobes. A nonlinear age effect was observed in the left and right frontal, and right temporal lobes. Differential patterns of age effects were observed in both sexes with relatively more age-affected regions in males. Significantly higher rightward asymmetries at hemisphere, frontal, parietal, and occipital lobe level and higher leftward asymmetry in temporal lobe were observed. There was no age-by-sex-by asymmetry interaction in any region. When controlling for brain size, the leftward hemispheric, and temporal lobe asymmetry decreased with age. Males had significantly lower asymmetry between hemispheres and higher asymmetry in the parietal and occipital lobes than females. This work provides distinct patterns of age-related sex and asymmetry differences that can aid in the future development of sex-specific models of the normal brain to ascribe cognitive functional significance of these patterns in ageing.