Social and Behavioral Sciences Commons^™

Perirhinal Cortex Contributes To Accuracy In Recognition Memory And Perceptual Discriminations., Edward B O'Neil, Anthony D Cate, Stefan Köhler

Brain and Mind Institute Researchers' Publications

The prevailing view of the medial temporal lobe (MTL) holds that its structures are dedicated to long-term declarative memory. Recent evidence challenges this position, suggesting that perirhinal cortex (PRc) in the MTL may also play a role in perceptual discriminations of stimuli with substantial visual feature overlap. Relevant neuropsychological findings in humans have been inconclusive, likely because studies have relied on patients with large and variable MTL lesions. Here, we conducted a functional magnetic resonance imaging study in healthy individuals to determine whether PRc shows a performance-related involvement in perceptual oddball judgments that is comparable to its established role in …

Activity Loss Is Associated With Cognitive Decline In Age-Related Macular Degeneration., Barry W. Rovner, Robin J. Casten, Benjamin E. Leiby, William S. Tasman

Department of Psychiatry and Human Behavior Faculty Papers

BACKGROUND/METHODS: The objective of this study was to determine whether relinquishing cognitive, physical, and social activities is associated with an increased risk of cognitive decline in patients with age-related macular degeneration (AMD). We conducted a 3-year longitudinal study of 206 nondemented patients with AMD.

RESULTS: Twenty-three subjects (14.4%) declined cognitively. Age, sex, education, decline in visual acuity, and number of dropped activities were associated with cognitive decline; each additional dropped activity increased the risk by 58%. Subjects who relinquished three activities were 3.87 times (95% confidence interval, 1.95-7.76) more likely to become demented than subjects who relinquished no activities; those …

Breast Cancer Survival In Ontario And California, 1998-2006: Socioeconomic Inequity Remains Much Greater In The United States, Kevin M. Gorey

Social Work Publications

This study re-examined the differential effect of socioeconomic status on the survival of women with breast cancer in Canada and the United States. Ontario and California cancer registries provided 1,913 cases from urban and rural places. Stage-adjusted cohorts (1998-2000) were followed until 2006. Socioeconomic data were taken from population censuses. SES-survival associations were observed in California, but not in Ontario, and Canadian survival advantages in low-income areas were replicated. A better controlled and updated comparison reaffirmed the equity advantage of Canadian health care.

Breast Cancer Survival In Canada And The Usa: Meta-Analytic Evidence Of A Canadian Advantage In Low-Income Areas, Kevin M. Gorey

Social Work Publications

BACKGROUND: This study tested the hypothesis that relatively poor Canadian women with breast cancer have a survival advantage over their counterparts in the USA.

METHODS: Seventy-eight independent retrospective cohort (incidence between 1984 and 2000, followed until 2006) outcomes were synthesized. Fixed effects meta-regression models compared women with breast cancer in low-income areas of Canada and the USA.

RESULTS: Low-income Canadian women were advantaged on survival [rate ratio (RR) = 1.14; 95% confidence interval (CI) 1.13-1.15] and their advantage was even larger among women <65 years of age who are not yet eligible for Medicare coverage in the USA (RR = 1.21, 95% CI 1.18-1.24). Canadian advantages were also larger for node positive breast cancer, which may present with greater clinical and managerial discretion (RR = 1.40, 95% CI 1.30-1.50), and smaller when Hawaii, the state providing the most Canadian-like access, was the US comparator (RR = 1.12, 95% CI 1.01-1.20).

CONCLUSIONS: More inclusive health care insurance coverage in Canada vs the USA, particularly among each country's relatively …

Wait Times For Surgical And Adjuvant Radiation Treatment Of Breast Cancer In Canada And The United States: Greater Socioeconomic Inequity In America, Kevin M. Gorey

Social Work Publications

PURPOSE: The demand for cancer care has increased among aging North American populations as cancer treatment innovations have proliferated. Gaps between supply and demand may be growing. This study examined whether socioeconomic status has a differential effect on waits for surgical and adjuvant radiation treatment (RT) of breast cancer in Canada and the US.

METHODS: Ontario and California cancer registries provided 929 and 984 breast cancer cases diagnosed between 1998 and 2000 in diverse urban and rural places. Residence-based socioeconomic data were taken from censuses. Cancer care variables were reliably abstracted from health records: stage, receipt of surgery and RT, …

Associations Of Physician Supplies With Breast Cancer Stage At Diagnosis And Survival In Ontario, 1988 To 2006, Kevin M. Gorey

Social Work Publications

BACKGROUND: The authors examined whether the supply of primary care physicians had protective effects on breast cancer stage and survival in Ontario and whether supply losses during the 1990s were associated with diminished protection.

METHODS: Random samples of the Ontario Cancer Registry, respectively, provided 879 women and 951 women who were diagnosed with breast cancer between 1988 and 1990 (followed until 1996) and 1998 and 2000 (followed until 2006), respectively. Active physician supply data (1991 and 2001) joined to each woman's census division of residence was taken from the Scott's Medical Database.

RESULTS: Protective thresholds were observed among the earlier …

Computing Travel Time When The Exact Address Is Unknown: A Comparison Of Point And Polygon Zip Code Approximation Methods, Ethan M. Berke, Xun Shi

Dartmouth Scholarship

Travel time is an important metric of geographic access to health care. We compared strategies of estimating travel times when only subject ZIP code data were available.Using simulated data from New Hampshire and Arizona, we estimated travel times to nearest cancer centers by using: 1) geometric centroid of ZIP code polygons as origins, 2) population centroids as origin, 3) service area rings around each cancer center, assigning subjects to rings by assuming they are evenly distributed within their ZIP code, 4) service area rings around each center, assuming the subjects follow the population distribution within the ZIP code. We used …

Increased Racial Differences On Breast Cancer Care And Survival In America: Historical Evidence Consistent With A Health Insurance Hypothesis, 1975-2001, Kevin M. Gorey

Social Work Publications

PURPOSE: This study examined whether race/ethnicity had differential effects on breast cancer care and survival across age strata and cohorts within stages of disease.

METHODS: The Detroit Cancer Registry provided 25,997 breast cancer cases. African American and non-Hispanic white, older Medicare-eligible and younger non-eligible women were compared. Successive historical cohorts (1975-1980 and 1990-1995) were, respectively, followed until 1986 and 2001.

RESULTS: African American disadvantages on survival and treatments increased significantly, particularly among younger women who were much more likely to be uninsured. Within node positive disease all treatment disadvantages among younger African American women disappeared with socioeconomic adjustment.

CONCLUSIONS: Growth …

Small Individual Loans And Mental Health: A Randomized Controlled Trial Among South African Adults, Lia C. H. Fernald, Rita Hamad, Dean Karlan, Emily J. Ozer, Jonathan Zinman

Dartmouth Scholarship

Background: In the developing world, access to small, individual loans has been variously hailed as a poverty-alleviation tool – in the context of "microcredit" – but has also been criticized as "usury" and harmful to vulnerable borrowers. Prior studies have assessed effects of access to credit on traditional economic outcomes for poor borrowers, but effects on mental health have been largely ignored.

Methods: Applicants who had previously been rejected (n = 257) for a loan (200% annual percentage rate – APR) from a lender in South Africa were randomly assigned to a "second-look" that encouraged loan officers to approve their …

Is American Health Care Uniquely Inefficient?, Alan M. Garber, Jonathan Skinner

Dartmouth Scholarship

No abstract provided.

Freesurfer-Initiated Fully-Automated Subcortical Brain Segmentation In Mri Using Large Deformation Diffeomorphic Metric Mapping., Ali R Khan, Lei Wang, Mirza Faisal Beg

Brain and Mind Institute Researchers' Publications

Fully-automated brain segmentation methods have not been widely adopted for clinical use because of issues related to reliability, accuracy, and limitations of delineation protocol. By combining the probabilistic-based FreeSurfer (FS) method with the Large Deformation Diffeomorphic Metric Mapping (LDDMM)-based label-propagation method, we are able to increase reliability and accuracy, and allow for flexibility in template choice. Our method uses the automated FreeSurfer subcortical labeling to provide a coarse-to-fine introduction of information in the LDDMM template-based segmentation resulting in a fully-automated subcortical brain segmentation method (FS+LDDMM). One major advantage of the FS+LDDMM-based approach is that the automatically generated segmentations generated are …

Effects Of Acute Ethyl Alcohol Consumption On A Psychophysical Measure Of Lateral Inhibition In Human Vision., Kevin D Johnston, Brian Timney

Brain and Mind Institute Researchers' Publications

Acute consumption of ethyl alcohol affects a variety of visual functions. However, there have been few systematic attempts to investigate the neural mechanisms underlying these effects. Here, we employed the Westheimer paradigm to investigate the hypothesis that alcohol reduces lateral inhibition within human "perceptive fields", the psychophysical analogue of physiological receptive fields. Westheimer functions obtained under alcohol and no-alcohol conditions at photopic, mesopic, and scotopic levels of adaptation showed changes consistent with an alcohol-induced decrease in lateral inhibition. We conclude that this decrease in lateral inhibition may be responsible for some of the changes in visual perception that result from …

Using Built Environment Characteristics To Predict Walking For Exercise, Gina S. Lovasi, Anne V. Moudon, Amber L. Pearson, Philip M. Hurvitz, Eric B. Larson, David S. Siscovick, Ethan M. Berke

Dartmouth Scholarship

Environments conducive to walking may help people avoid sedentary lifestyles and associated diseases. Recent studies developed walkability models combining several built environment characteristics to optimally predict walking. Developing and testing such models with the same data could lead to overestimating one's ability to predict walking in an independent sample of the population. More accurate estimates of model fit can be obtained by splitting a single study population into training and validation sets (holdout approach) or through developing and evaluating models in different populations. We used these two approaches to test whether built environment characteristics near the home predict walking for …

Lower Adherence To Screening Mammography Guidelines Among Ethnic Minority Women In America: A Meta-Analytic Review, Rebecca J. Purc-Stephenson, Kevin M. Gorey

Social Work Publications

OBJECTIVE: This study investigates the association between ethnic minority status and receiving a screening mammogram within the past 2 years among American women over 50.

METHOD: The findings from 33 studies identified from interdisciplinary research databases (1980 to 2006) were synthesized. Separate pooled analyses compared white non-Hispanics to African Americans (28 outcomes), Hispanics (18 outcomes), and Asian/Pacific Islanders (10 outcomes).

RESULTS: Using the random effects model, results showed that African Americans were screened less than white non-Hispanics at a marginal level (OR 0.87, 95% CI 0.75, 1.00). Larger and significant discrepancies were observed for Hispanics (OR 0.65, 95% CI 0.50, …

Cancer Survival In Ontario, 1986-2003: Evidence Of Equitable Advances Across Most Diverse Urban And Rural Places, Kevin M. Gorey

Social Work Publications

OBJECTIVES: This study examined whether place and socio-economic status had differential effects on the survival of women diagnosed with breast cancer in Ontario during the 1980s and the 1990s.

METHODS: The Ontario Cancer Registry provided 29,934 primary malignant breast cancer cases. Successive historical cohorts (1986-1988 and 1995-1997) were, respectively, followed until 1994 and 2003. Diverse places were compared: the greater metropolitan Toronto area, other cities, ranging in size from 50,000 to a million people, smaller towns and villages, and rural and remote areas. Socio-economic data for each woman's residence at the time of diagnosis were taken from population censuses.

RESULTS: …

Reflex Changes Associated With Anticipatory Postural Adjustments Preceding Voluntary Arm Movements In Standing Humans, Siddharth Vedula, Paul J. Stapley, Robert E. Kearney

Faculty of Health and Behavioural Sciences - Papers (Archive)

Dynamic changes in human stability, such as those induced by upper body movements, are preceded by anticipatory postural adjustments (APAs) in the rest of the body. We measured the excitability of the stretch reflex of the triceps-surae muscle group during APAs associated with unilateral right arm raises in standing humans. Our results demonstrate that reflex excitability and underlying muscle activity are linked during the APA period, but that they differ in their relative timing. This supports the idea that reflexes are controlled independently of muscle activation.

Clinic Variation In The Cost-Effectiveness Of Contingency Management, Todd A. Olmstead, Nancy M. Petry

UCHC Articles - Research

This study determined whether, and by how much, the cost-effectiveness of contingency management (CM) varied across the eight clinics in the National Institute on Drug Abuse Clinical Trials Network MIEDAR trial. Incremental costs, incremental outcomes, and incremental costeffectiveness ratios (ICERs) of CM compared to usual care were calculated, compared and contrasted for each of the clinics. Results showed that the incremental cost of using CM compared to usual care varied by a factor of 1.9 across the clinics, ranging from an additional $306 to an additional $582 per patient. The effect of CM on the longest duration of continuous stimulant …

Human Parietal "Reach Region" Primarily Encodes Intrinsic Visual Direction, Not Extrinsic Movement Direction, In A Visual Motor Dissociation Task., Juan Fernandez-Ruiz, Herbert C Goltz, Joseph F X Desouza, Tutis Vilis, J Douglas Crawford

Brain and Mind Institute Researchers' Publications

Posterior parietal cortex (PPC) participates in the planning of visuospatial behaviors, including reach movements, in gaze-centered coordinates. It is not known if these representations encode the visual goal in retinal coordinates, or the movement direction relative to gaze. Here, by dissociating the intrinsic retinal stimulus from the extrinsic direction of movement, we show that PPC employs a visual code. Using delayed pointing and event-related functional magnetic resonance imaging, we identified a cluster of PPC regions whose activity was topographically (contralaterally) related to the direction of the planned movement. We then switched the normal visual-motor spatial relationship by adapting subjects to …

Neuropathological Findings Processed By Artificial Neural Networks (Anns) Can Perfectly Distinguish Alzheimer's Patients From Controls In The Nun Study, Enzo Grossi, Massimo P. Buscema, David Snowdon, Piero Antuono

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: Many reports have described that there are fewer differences in AD brain neuropathologic lesions between AD patients and control subjects aged 80 years and older, as compared with the considerable differences between younger persons with AD and controls. In fact some investigators have suggested that since neurofibrillary tangles (NFT) can be identified in the brains of non-demented elderly subjects they should be considered as a consequence of the aging process. At present, there are no universally accepted neuropathological criteria which can mathematically differentiate AD from healthy brain in the oldest old. The aim of this study is to discover …

Alcohol Slows Interhemispheric Transmission, Increases The Flash-Lag Effect, And Prolongs Masking: Evidence For A Slowing Of Neural Processing And Transmission., Sarah A Khan, Brian Timney

Brain and Mind Institute Researchers' Publications

While the alcohol literature is extensive, relatively little addresses the relationship between physiological effects and behavioural changes. Using the visual system as a model, we examined alcohol's influence on neural temporal processing as a potential means for alcohol's effects. We did this by using tasks that provided a measure of processing speed: Poffenberger paradigm, flash-lag, and backward masking. After moderate alcohol, participants showed longer interhemispheric transmission times, larger flash-lags, and prolonged masking. Our data are consistent with the view that alcohol slows neural processing, and provide support for a reduction in processing efficiency underlying alcohol-induced changes in temporal visual processing.

Pregnant Teenager Involvement In Sexual Activity And The Social Context, Maria José Carvalho Sant'anna, Júlia Kerr Catunda, Kepler Alencar Mendes Carvalho, Verônica Coates, Hatim A. Omar

Pediatrics Faculty Publications

Pregnancy during adolescence represents a challenge to society as a whole. Its incidence is increasing and brings about social and medical consequences to both the teen mothers and their children. The purpose of this study was to evaluate pregnant teenager involvement in sexual activity and the social context. The group studied comprised 152 pregnant teenagers attending the Department of Pediatrics, Santa Casa de Sao Paulo (SCSP) General Hospital. All information was analyzed. The age at first intercourse was 14.2 years and the average period between first intercourse and pregnancy was 1.4 years. Most pregnancies (75%) were neither planned nor wanted, …

Depression, Sensation Seeking, And Maternal Smoking As Predictors Of Adolescent Cigarette Smoking, Judy Van De Venne, Kay Bradford, Catherine A. Martin, Megan Cox, Hatim A. Omar

Family Sciences Faculty Publications

The purpose of this study was to examine maternal and adolescent depression, maternal and teen sensation seeking, and maternal smoking, and their associations with adolescent smoking. Data were collected from a sample of 47 male and 66 female adolescents (ages 11-18 years) and their mothers from three different health clinics. The findings indicated that maternal sensation seeking was linked indirectly with adolescent smoking through teen sensation seeking, both of which were significantly associated with teen smoking (β = 0.29, p < 0.001 and β = 0.32, p < 0.001, respectively). Teen depression was associated positively with teen smoking (β = 0.24, p < 0.01) when controlling for sensation seeking behaviors. Maternal smoking was also directly linked to adolescent smoking (β = 0.20, p < 0.05). These findings underscore a potentially important role of sensation seeking in the origins of adolescent smoking, and clarify pathways of influence with regard to maternal attitudes and behaviors in subsequent teenage nicotine use.

Representation Of Head-Centric Flow In The Human Motion Complex., Jeroen Goossens, Sean P Dukelow, Ravi S Menon, Tutis Vilis, Albert V Van Den Berg

Brain and Mind Institute Researchers' Publications

Recent neuroimaging studies have identified putative homologs of macaque middle temporal area (area MT) and medial superior temporal area (area MST) in humans. Little is known about the integration of visual and nonvisual signals in human motion areas compared with monkeys. Through extra-retinal signals, the brain can factor out the components of visual flow on the retina that are induced by eye-in-head and head-in-space rotations and achieve a representation of flow relative to the head (head-centric flow) or body (body-centric flow). Here, we used functional magnetic resonance imaging to test whether extra-retinal eye-movement signals modulate responses to visual flow in …

A Contralateral Preference In The Lateral Occipital Area: Sensory And Attentional Mechanisms., Matthias Niemeier, Herbert C Goltz, Anil Kuchinad, Douglas B Tweed, Tutis Vilis

Brain and Mind Institute Researchers' Publications

Here we examined the level of the lateral occipital (LO) area within the processing stream of the ventral visual cortex. An important determinant of an area's level of processing is whether it codes visual elements on both sides of the visual field, as do higher visual areas, or prefers those in the contralateral visual field, as do early visual areas. The former would suggest that LO, on one side, combines bilateral visual elements into a whole, while the latter suggests that it codes only the parts of forms. We showed that LO has a relative preference for visual objects in …

The Consequences Of The Growth Of Health Insurance Premiums, Katherine Baicker, Amitabh Chandra

Dartmouth Scholarship

n the United States, two-thirds of the non-elderly population is covered by employer- provided health insurance (EHI). According to a Kaiser Family Foundation national survey (2003), the cost of EHI has increased by over 59 percent since 2000 with no accompanying in- crease in the scale or scope of benefits. These increases in health insurance premiums may have significant effects on labor markets, including changes in the number of jobs, hours worked per employee, wages, and compensation packages. Indeed, it is possible that a significant portion of the increase in the uninsured population may be a consequence of employers shedding …

Multijurisdictional Approach To Biosurveillance, Kansas City., Mark A Hoffman, Tiffany H Wilkinson, Aaron Bush, Wayne Myers, Ron G Griffin, Gerald L Hoff, Rex Archer

Manuscripts, Articles, Book Chapters and Other Papers

No abstract provided.

Gaze-Centered Updating Of Visual Space In Human Parietal Cortex., W Pieter Medendorp, Herbert C Goltz, Tutis Vilis, J Douglas Crawford

Brain and Mind Institute Researchers' Publications

Single-unit recordings have identified a region in the posterior parietal cortex (PPC) of the monkey that represents and updates visual space in a gaze-centered frame. Here, using event-related functional magnetic resonance imaging, we identified an analogous bilateral region in the human PPC that shows contralateral topography for memory-guided eye movements and arm movements. Furthermore, when eye movements reversed the remembered horizontal target location relative to the gaze fixation point, this PPC region exchanged activity across the two cortical lobules. This shows that the human PPC dynamically updates the spatial goals for action in a gaze-centered frame.

The Lateral Occipital Complex Subserves The Perceptual Persistence Of Motion-Defined Groupings., Susanne Ferber, G Keith Humphrey, Tutis Vilis

Brain and Mind Institute Researchers' Publications

How are the bits and pieces of retinal information assembled and integrated to form the coherent objects that we see? One long-established principle is that elements that move as a group are linked together. For instance a fragmented line-drawing of an object, placed on a background of randomly distributed short lines, can be impossible to see. But if the object moves relative to the background, its shape is instantly recognized. Even after the motion stops, the percept of the object persists briefly before it fades into the background of random lines. Where in the brain does the percept of the …

Effects Of Ethanol On Anti-Saccade Task Performance., Sarah A Khan, Kristen Ford, Brian Timney, Stefan Everling

Brain and Mind Institute Researchers' Publications

It has been shown that saccade-related neurons in the superior colliculus (SC) display an increased level of prestimulus activity and a higher stimulus-related burst in action potentials preceding direction errors in the anti-saccade task compared with correct anti-saccades. From this, it has been hypothesized that errors occur when the incoming visual signal in the SC passes a threshold and triggers a reflexive saccade. This hypothesis predicts that an attenuated visual signal will reduce the number of direction errors. Since ethanol has been shown to have a suppressive effect on cortical visual event-related potentials (ERPs), the purpose of the present study …

An International Comparison Of Breast Cancer Survival: Winnipeg, Manitoba And Des Moines, Iowa, Metropolitan Areas, Kevin M. Gorey

Social Work Publications

PURPOSE: Extending previous Canadian-United States cancer survival comparisons in large metropolitan areas, this study compares breast cancer survival in smaller metropolitan areas: Winnipeg, Manitoba and Des Moines, Iowa.

METHODS: Manitoba and Iowa cancer registries, respectively, provided a total of 2,383 and 1,545 women with breast cancer (1984 to 1992, followed until December 31, 1997). Socioeconomic data for each person's residence at the time of diagnosis was taken from population censuses.

RESULTS: Socioeconomic status and breast cancer survival were directly associated in the US cohort, but not in the Canadian cohort. Compared with similar patients in Des Moines, residents of the …