Color-detection thresholds in rhesus macaque monkeys and humans.

Macaque monkeys are a model of human color vision. To facilitate linking physiology in monkeys with psychophysics in humans, we directly compared color-detection thresholds in humans and rhesus monkeys. Colors were defined by an equiluminant plane of cone-opponent color space. All subjects were tested on an identical apparatus with a four-alternative forced-choice task. Targets were 2° square, centered 2° from fixation, embedded in luminance noise. Across all subjects, the change in detection thresholds from initial testing to plateau performance ("learning") was similar for +L − M (red) colors and +M − L (bluish-green) colors. But the extent of learning was higher for +S (lavender) than for −S (yellow-lime); moreover, at plateau performance, the cone contrast at the detection threshold was higher for +S than for −S. These asymmetries may reflect differences in retinal circuitry for S-ON and S-OFF. At plateau performance, the two species also had similar detection thresholds for all colors, although monkeys had shorter reaction times than humans and slightly lower thresholds for colors that modulated L/M cones. We discuss whether these observations, together with previous work showing that monkeys have lower spatial acuity than humans, could be accounted for by selective pressures driving higher chromatic sensitivity at the cost of spatial acuity amongst monkeys, specifically for the more recently evolved L − M mechanism.

Effect of Patients' Life Stories in Bringing Meaning to Nursing Home Care.

INTRODUCTION: Although there is an increasing need for geriatricians, fewer physicians are entering the field. Family medicine residents find geriatrics, especially nursing home care, unsatisfying. Life stories of older adult patients may help providers cope with the challenges of nursing home care and increase provider satisfaction by offering a way to connect with patients. METHODS: We conducted a qualitative study on life stories' effects on attitudes towards nursing home care. Fourteen patient stories were created. Seven Boston University family medicine residents and one nurse practitioner participated in a semistructured interview both before and at least 2 months after learning about their patients' stories. Data were analyzed using qualitative techniques from grounded theory. RESULTS: Participants found nursing home care challenging, particularly for patients who were nonverbal due to advanced dementia, because they had difficulties forming meaningful relationships or discussing medical decisions with their patients. Life stories increased empathy, deepened relationships with patients, and led participants to feel more satisfied in their role as providers. The stories were considered useful for end-of-life discussions. CONCLUSION: Life stories incorporated into physician practice may help health care providers feel more connected to their patients and ultimately more satisfied in the care of nursing home patients.