Patient-driven N-of-1 in Parkinson's Disease. Lessons Learned from a Placebo-controlled Study of the Effect of Nicotine on Dyskinesia.

Background: New insights and knowledge in biomedical science often come from observation and experimentation. Methods traditionally used include self-experimentation, case reports, randomised controlled trials, and N-of-1 studies. Technological advances have lead to an increasing number of individuals and patients engaging in self-tracking.

Psychophysical evidence for losses in rod sensitivity in the aging visual system.

Rod sensitivity was measured with a criterion-free psychophysical method at 10 deg in the horizontal meridian of the nasal field of the left eye on 26 young (mean age, 24.1 yr) and 14 older (mean age 72.6 yr) observers in good ocular health.

Photophobia in patients with traumatic brain injury: Uses of light-filtering lenses to enhance contrast sensitivity and reading rate.

Patients who have sustained traumatic brain injury (TBI) often experience a new, intense and chronic photophobia. Photophobia, an intolerance to light, is an incompletely understood, subjective symptom, which has been divided into ocular and central types. Various commercial sources of light-filtering lenses have been developed, which have proven to be successful in diminishing visual symptoms expressed by patients who are photophobic.

Aging, background luminance, and threshold-duration functions for detection of low spatial frequency sinusoidal gratings.

Purpose: This study examined the temporal summation properties of the aging visual system under a wide range of background luminances.

Methods: Contrast thresholds for 0.5 cpd gratings for 12 younger (mean age 20.

Performance of young and older drivers on a static acuity test under photopic and mesopic luminance conditions.

Sixty young (18-25 years) and 91 older volunteers (60-87 years) were tested for static visual acuity under six different luminance levels ranging from 245.5 cd/m2 (photopic) to 0.2 cd/m2 (mesopic).

Temporal summation functions for detection of sine-wave gratings in young and older adults.

Temporal summation functions for 0.416 and 7.5 c/deg sinusoidal gratings were measured in young and old observers in order to test the hypothesis of a shift in sensitivity from "transient" to "sustained" channels in the aging visual system.

Visual information processing speed in hypnotized and nonhypnotized subjects.

Using a backward-masking paradigm with a bias-free and ceiling-free psychophysical task, we tested hypnotized and control subjects for speed of visual information processing. Approximately half of each group received visual imagery suggestions in an attempt to influence attention. Imagery produced no significant differential effect.

Selective attenuation in brightness for brief stimuli and at low intensities supports age-related transient channel losses.

A brightness estimation experiment was conducted on 10 old (ages 60 to 77) and 10 young (ages 22 to 27) volunteers. Participants were introduced to magnitude estimation by scaling the lengths of line stimuli, after which they dark adapted for 10 minutes. Stimuli for brightness estimation were presented binocularly via a free-viewing system and consisted of circular flashes of 2 degrees.

Comprehension of informed consent information by young-old through old-old volunteers.

Comprehension of typewritten informed consent information was evaluated for young-old (60-69 years) through old-old (80-89 years) volunteers as a function of years of education (less than 12, 12, and greater than 12), readability of information (low [college level] vs high [7th grade]), and typeface used in the preparation of the materials (Prestige Elite 72, Letter Gothic, and Orator). All volunteers (N = 235) read a typewritten information sheet and retained it for review while answering eight multiple choice questions. Immediate feedback was provided, and a second test was administered if any answers were incorrect.

Older observers have attenuated increment thresholds upon transient backgrounds.

Foveal increment thresholds were measured in young, middle-aged, and older observers. These thresholds, which involved the detection of a small test flash as a function of the intensity of a larger background adapting field (AF), were measured at the instant of onset of the AF (transient condition) and when the eye had been fully light adapted to the AF (steady-state condition). All stimuli were presented to the left eye in a free-viewing system through a 2 mm artificial pupil.

Reading disability: a hemispheric asymmetry--information processing approach.

A visual half-field task using a Sperling partial-report paradigm was presented to 10 reading disabled and 10 control subjects (7 to 14 yr. old). The design was very similar to that described in 1977 by Morrison, Giordani, and Nagy, examining performance of letters placed in a circular array at both the perceptual and short-term memory stage.

Informed consent for research. Effects of readability, patient age, and education.

Comprehension of informed consent materials from a study of psychological variables associated with chest pain was evaluated as a function of age (27 to 69 years), education (5 to 20 years), and readability of information [low (college level) versus high (7th grade)]. The potentially confounding effect of memory was eliminated by allowing patients to use the written information sheets to find answers to the multiple choice test. Feedback and a repeat test were provided if any answers were incorrect.