The Role Of The Ventromedial Prefrontal Cortex In Value-Based Decision-Making

The ventromedial prefrontal cortex (vmPFC) has been shown to correlate with the subjective value for options, across reward type and across hundreds of functional neuroimaging studies. Despite the prominence of its role in preference-based decision-making, its specific contributions to how decisions are made have not yet been well-characterised. Study 1 addresses what the vmPFC signal represents during decision-making. While the vmPFC signal has been shown to correlate highly with subjective value in past studies, this signal is also consistent with mental navigation through a conceptual attribute space using a grid-like code. We found that the mental navigation model lacked support in the evidence, and the subjective value model remains the best explanation for vmPFC signal during decision-making. After having established that the signal in vmPFC reflects subjective value, Study 2 addresses whether subjective value representations remain consistent for non-choice preference tasks, and when this representation comes online during the decision process. This study shows that the value network seen previously for choice tasks also is active during a matching bidding task, and that the vmPFC, interestingly, represents value only at the time of the final choice. Finally, in Study 3, I address the question of how the vmPFC is necessary for subjective value in my third chapter. Transitivity (the idea that if A \u3e B, and B \u3e C, then A \u3e C) is a key property of a value-based system. Individuals with ventromedial frontal lobe damage have been found to make more transitivity errors in the past, but it is not known whether vmPFC damage causes fundamentally intransitive choices (implying abolishment of value), or transitive but noisier choices (implying preservation of value but increased instability). We found strong evidence for the second case, demonstrating that vmPFC damage adds instability to valuation but does not abolish it. The evidence I present here is consistent with the theory that vmPFC is involved in a subjective value-based process during decision-making, yet that value is a distributed process over many brain regions where other regions may compensate for the loss of the vmPFC in calculating value

Undergraduate International Student Enrollment Forecasting Model: An Application of Time Series Analysis

This study developed statistical models to forecast international undergraduate student enrollment at a Midwest university. The authors constructed a SARIMA (Seasonal Autoregressive Integrated Moving Average) model with input variables to estimate future enrollment. The SARIMA model reflected enrollment patterns by semester through highlighting seasonality. Further, authors added input variables such as visa policy changes, the rapid increase of Chinese undergraduate enrollment, and tuition rate into the model estimation. The visa policy change and the increase of Chinese undergraduate enrollment were significant predictors of international undergraduate enrollment. The effect of tuition rates was significant but minimal in magnitude. Findings of this study generate significant implications for policy, enrollment management, and student services for international students

Community environment, cognitive impairment and dementia in later life: results from the Cognitive Function and Ageing Study

Background: Few studies have investigated the impact of the community environment, as distinct from area deprivation, on cognition in later life. This study explores cross-sectional associations between cognitive impairment and dementia and environmental features at the community level in older people. Method: The postcodes of the 2424 participants in the year-10 interview of the Cognitive Function and Ageing Study in England were mapped into small area level geographical units (Lower-layer Super Output Areas) and linked to environmental data in government statistics. Multilevel logistic regression was conducted to investigate associations between cognitive impairment (defined as MMSE3 in GMS-AGECAT) and community level measurements including area deprivation, natural environment, land use mix and crime. Sensitivity analyses tested the impact of people moving residence within the last two years. Results: Higher levels of area deprivation and crime were not significantly associated with cognitive impairment and dementia after accounting for individual level factors. Living in areas with high land use mix was significantly associated with a nearly 60% reduced odds of dementia (OR: 0.4; 95% CI: 0.2, 0.8) after adjusting for individual level factors and area deprivation, but there was no linear trend for cognitive impairment. Increased odds of dementia (OR: 2.2, 95% CI: 1.2, 4.2) and cognitive impairment (OR: 1.4, 95% CI: 1.0, 2.0) were found in the highest quartile of natural environment availability. Findings were robust to exclusion of the recently relocated. Conclusion: Features of land use have complex associations with cognitive impairment and dementia. Further investigations should focus on environmental influences on cognition to inform health and social policies

Infants’ Developing Coordinated Visual-Manual Object Exploration and Linkswith Vocabulary Development

Research has demonstrated links between visual and manual object exploration and infants’ object perception (e.g.,Soska, Adolph, & Johnson, 2010). However, systematic investigation of the development of visual and manual object explo-ration and potential cascading effects on early word learning is lacking. In a longitudinal study of infants aged 9 to 24 months,we captured dynamic visual and manual information using head-mounted eye tracking and motion tracking of infants’ handsas infants and their parents played with objects. Parents completed the MCDI vocabulary assessment at every visit. We willpresent preliminary data investigating individual and developmental differences in visual and manual object exploration, theresulting object views that are generated, and their relation to word learning. The results will inform our understanding of therelations between motor development, visual attention, and word learning in infancy

Finding Clarity Amidst the Clutter: How Parents Name Objects

A core issue in the study of word learning is understanding how beginning learners cope with referential ambiguityin the clutter of natural learning environments, and how parents may help them find the referent in that clutter. Here we ask howsensitive parents are in taking advantage of optimal visual moments where a single object is visually large in view to providelinguistic labels for their infants. Using a mini-head camera, we recorded parent-child free play interactions and studied theparent naming events for 12 and 30 month old children from the infant-perspective in a context of high clutter (30 objectsdumped on the floor). Despite the cluttered context, parents and infants frequently created infant-perspective scenes in whichone object was visually singled out. At both age levels, parents named objects in these moments of visual clarity and almostnever named objects in sub-optimal moments

Community environment, cognitive impairment and dementia in later life: results from the Cognitive Function and Ageing Study

Background: Few studies have investigated the impact of the community environment, as distinct from area deprivation, on cognition in later life. This study explores cross-sectional associations between cognitive impairment and dementia and environmental features at the community level in older people. Method: The postcodes of the 2424 participants in the year-10 interview of the Cognitive Function and Ageing Study in England were mapped into small area level geographical units (Lower-layer Super Output Areas) and linked to environmental data in government statistics. Multilevel logistic regression was conducted to investigate associations between cognitive impairment (defined as MMSE3 in GMS-AGECAT) and community level measurements including area deprivation, natural environment, land use mix and crime. Sensitivity analyses tested the impact of people moving residence within the last two years. Results: Higher levels of area deprivation and crime were not significantly associated with cognitive impairment and dementia after accounting for individual level factors. Living in areas with high land use mix was significantly associated with a nearly 60% reduced odds of dementia (OR: 0.4; 95% CI: 0.2, 0.8) after adjusting for individual level factors and area deprivation, but there was no linear trend for cognitive impairment. Increased odds of dementia (OR: 2.2, 95% CI: 1.2, 4.2) and cognitive impairment (OR: 1.4, 95% CI: 1.0, 2.0) were found in the highest quartile of natural environment availability. Findings were robust to exclusion of the recently relocated. Conclusion: Features of land use have complex associations with cognitive impairment and dementia. Further investigations should focus on environmental influences on cognition to inform health and social policies