Claudia M. Hunter

• Ph.D.
• Researcher at Rensselaer Polytechnic Institute

Shift work, especially that involving rotating and night shifts, is associated with an increased risk of diseases, including cancer. Attempts to explain the association between shift work and cancer in particular have focused on the processes of melatonin production and suppression. One hypothesis postulates that exposure to light at night (LAN) su...

Background: By affecting the internal timing mechanisms of the brain, light regulates human physiology and behavior, perhaps most notably the sleep-wake cycle. Humans spend over 90% of their waking hours indoors, yet light in the built environment is not designed to affect circadian rhythms. Objective: Using a device calibrated to measure light...

Until we know more, it is recommended that lighting in health care facilities should be designed to minimize acute melatonin suppression in night shift workers.

Objectives: Light therapy has shown promise as a nonpharmacological treatment to help regulate abnormal sleep-wake patterns and associated behavioral issues prevalent among individuals diagnosed with Alzheimer's disease and related dementia (ADRD). The present study investigated the effectiveness of a lighting intervention designed to increase cir...

Previous research has shown that, given a high enough luminance, a significant number of people experience discomfort from a luminaire overhead. However, the data that led to this conclusion were obtained from people who were all knowledgeable about lighting and hence who might have had an enhanced sensitivity to lighting conditions. This paper des...

A lighting installation constructed from luminaries fitted with full-spectrum fluorescent lamps and multi-layer polarized panels provides full-spectrum, polarized lighting. It has been claimed that major energy savings in office lighting can be made by replacing conventional fluorescent lighting with full-spectrum, polarized lighting at a lower ill...

A convergent set of findings suggests that the phenomenal impression of a scene's structure contains representations of some of the viewed objects, set at relatively precise spatial locations in the visual field. The representation is thought to be limited to 4–5 objects by the capacity of visual short-term memory (Hunter, Warlaumont, and Edelman,...

As part of a larger study sponsored by the Light Right Consortium, temporary office workers spent a day in an office working under one of four different lighting installations. For two of these installations the office workers had the freedom to adjust the lighting of the cubicles they occupied: either with a switchable desk lamp, or varying the di...

This paper describes two experiments concerning the effects of variations in lighting quality on office worker performance, health, and well-being. Experiment 1 had four experimental conditions: a regular array of fully direct recessed parabolic luminaires; direct/indirect luminaires with no control; direct/indirect luminaires with a switchable des...

What does the phenomenal impression made by a scene consist of? The answer, we conjecture, is scene structure: objects and their locations (“what” + “where”). If this is so, the impression must persist, even if for a short time, at those stages of the visual pathway where units tuned both to complex shapes and their locations are present (specifica...

This experiment tests the hypothesis that light sources that produce smaller pupil sizes ensure better achromatic visual task performance at the same photopic illuminance. Two groups of subjects, one in the age range 18-28 years and the other in the range 61-78 years, performed a Landolt ring task for eight different gap sizes, two different illumi...

The question this study addressed was, "Can different forms of realistic office lighting affect the performance of office work or the health and well-being of employees?" An office was furnished as a typical open plan workplace for nine workers, with perimeter windows allowing access to a view but limited daylight penetration. Two experiments were...

The design of telepresence systems is a problem in both ethics and in human factors. Designers have an obligation to provide systems that meet society's needs and wants for surveillance, while preserving as much of its citizens' privacy as possible. The results of two surveys reported in this paper indicate that people have fewer concerns about sys...

Interior lighting design and selection can be a demanding assignment for a health facilities manager or department head. It requires a balance between conflicting needs, such as providing good task lighting for a nursing station while also shielding luminaires that are visible from patients' rooms to avoid glare.

This paper describes a study that compares the relative merits of high-intensity discharge vehicle headlamps with conventional halogen vehicle headlamps. Reaction times of study participants are measured. The study has implications for driving safety and for the ways in which it would be useful to refine vehicle headlamps.

An experimental field investigation is described that compares the off-axis visual performance of HID forward lighting systems with comparable halogen systems to determine the relative visual effects of HID lighting. This has been accomplished for European beam patterns; North American beam patterns are currently being examined. The goal of the inv...

The visual discomfort from simulated traffic signals under nighttime viewing conditions was assessed. Discomfort increased with increasing signal luminance and decreasing viewing distance. Color identification of signals was very high for all signal colors and luminances studied. Red signals meeting luminous intensity specifications of the Institut...

This report describes an evaluation of gas station canopy lighting using 3 types of luminaires: drop-lens, non-cutoff luminaires, in which the lamp is visible from far away; flat-lens, full-cutoff luminaires; and drop-lens, cutoff luminaires, in which the lamp is not visible from far away. The evaluations considered photometric conditions, energy e...

The successful creation of telepresence and virtual environments requires a change in design paradigm. We must move away from attempts to recreate reality in its entirety toward the creation of environments that are psychologically real for humans, because in fact, reality mediated through display devices is largely subjective. The experiments disc...

The rise time of a light source is the time it takes to reach full light output after application of power. Different light sources used in traffic signals have different minimum rise times. LEDs have minimum rise times in the order of nanoseconds, while incandescent lamps have minimum rise times in the order of tens of milliseconds. Whether these...

Simulated light-emitting diode (LED) traffic signals of different luminances were evaluated relative to incandescent signals of the same nominal color and at the luminances required by the specifications of the Institute of Transportation Engineers. Measurements were made of the reaction times to onset and the number of missed signals for red, yell...

Luminous Intensity for Traffic Signals: A Scientific Basis for Performance Specifications - Appendices

This study examines potential mappings between the subjective experience of speed when mediated through visual display devices and the physical velocity of a vehicle, especially when the apparatus for experiencing speed and the actual vehicle are not in the same scale. Such mappings are important for creating psychological reality in telepresence e...

Humnan factors experiments on visual responses to simulated traffic signals using incandescent lamps and light-emitting diodes are described.

Capturing the Daylight Dividend conducted activities to build market demand for daylight as a means of improving indoor environmental quality, overcoming technological barriers to effective daylighting, and informing and assisting state and regional market transformation and resource acquisition program implementation efforts. The program clarified...