Comparison of fundus autofluorescence and minimum-motion measurements of macular pigment distribution profiles derived from identical retinal areas

The optical density of macular pigment was measured at twelve retinal locations in ten subjects by minimum motion photometry, comparing 460 nm with 580 nm or 550 nm. Fundus autofluorescence images were obtained for the same subjects with a scanning laser ophthalmoscope. Optical density was computed from mean calibrated grey-scale values for a central circular field and for annular segments, identical to areas tested psychophysically, and for complete annuli. Psychophysical assessments of optical density were similar irrespective of whether 550 nm or 580 nm was used. Optical density values derived psychophysically showed a linear correlation with assessments based on identical sampled areas of annular segments (slope = 0.98, r2 = 0.97) or complete annuli (slope = 0.89, r2 = 0.96) in autofluorescence images.     

A functional analytic approach to computer-interactive mathematics

Following a pretest, 11 participants who were naive with regard to various algebraic and trigonometric transformations received an introductory lecture regarding the fundamentals of the rectangular coordinate system. Following the lecture, they took part in a computer-interactive matching-to-sample procedure in which they received training on particular formula-to-formula and formula-to-graph relations as these formulas pertain to reflections and vertical and horizontal shifts. In training A-B, standard formulas served as samples and factored formulas served as comparisons. In training B-C, factored formulas served as samples and graphs served as comparisons. Subsequently, the program assessed for mutually entailed B-A and C-B relations as well as combinatorially entailed C-A and A-C relations. After all participants demonstrated mutual entailment and combinatorial entailment, we employed a test of novel relations to assess 40 different and complex variations of the original training formulas and their respective graphs. Six of 10 participants who completed training demonstrated perfect or near-perfect performance in identifying novel formula-to-graph relations. Three of the 4 participants who made more than three incorrect responses during the assessment of novel relations showed some commonality among their error patterns. Derived transfer of stimulus control using mathematical relations is discussed.     

The ethic of caring: the moral response to suffering

An ethic of care can be distinguished from an ethic based on autonomous rights, utilitarian principles, or indeed principles of any kind, since care has less to do with intellect than with emotions and will. Moreover, an ethic of care is consistent with the example of Jesus and the virtues advocated by the apostle Paul. Emily A. Hitchens and Lilyan S. Snow make their case with particular reference to accounts by Civil War nurses, who developed the skills of care without precedent and without the expectation of cure that scientific medicine has aroused.     

The effects of stressful arousal on conjugate lateral eye movement

This study investigated the relationship between stressful arousal and conjugate lateral eye movement tendencies in right-handed males. Sixty subjects were asked both neutral and mildly emotional questions after watching either a stressful industrial accident movie or a bland control film. Subjects had been previously classified as either right-movers, left-movers, or bidirectionals on the basis of their responses in a prefilm interview. A statistically significant interaction between dominant direction and film condition was found on right eye movement. Subjects classified as right-movers displayed increased right eye movement preferences under the stress film, compared to the neutral film condition. This effect was seen with neutral, but not mildly emotional, questions. Results were interpreted within an elaborated brain asymmetry model of conjugate lateral eye movement, in which stressful arousal is assumed to increase subjects' reliance on characteristic, neurologically based ways of dealing with stimuli. Implications for theory and research on brain-behavior relationships in ego-defensive styles are discussed.     

Recovery from aphasia: Spontaneous speech versus language comprehension

Seventy-four aphasic patients, subdivided into four groups (fluent, mixed, nonfluent, and severely nonfluent), were tested three times in the course of 1 year to assess recovery of spontaneous speech and sentence comprehension. Although 12 of the 28 spontaneous speech variables employed showed significant time changes, some of these changes indicated improvement and others deterioration. There was no overall clinical improvement in spontaneous speech in any group. On the sentence comprehension tests, however, all four groups did show considerable, significant improvement. There were no qualitative or quantitative differences among the groups in the course of recovery, despite the fact that the groups differed in the severity of aphasia as well as on the fluency dimension. In certain patients there was also some improvement in spontaneous speech, but this did not in most cases correlate with an improvement in either fluency or sentence comprehension. Possible reasons why receptive abilities improved more than expressive abilities are discussed.     

Considerations in software character generation

Two concerns about the development of a computer-driven display system to achieve tachistoscopic displays are discussed. Approaches to solving these problems are described.     

A visual display system for reading and visual perception research

The selection of a computer visual display system suitable for word recognition and reading research is described. The software character generation routines permit flexible definition of character sets. The display software permits control of size scaling and point density of characters being displayed as well as control over the temporal microstructure of presenting and refreshing the displayed text.     

Isolating visual units in the perception of words and nonwords

In three experiments, reaction times for same-different judgments were obtained for pairs of words, pronounceable nonwords (pseudowords), and unpronounceable nonwords. The stimulus strings were printed either in a single letter case or in one of several mixtures of upper- and lowercase letters. In Experiment 1, the stimuli were common one- and two-syllable words; in Experiment 2, the stimuli included both words and pseudowords; and in Experiment 3, words, pseudowords, and nonwords were used. The functional visual units for each string type were inferred from the effects that the number and placement of letter case transitions had onsame reaction time judgments. The evidence indicated a preference to encode strings in terms of multiletter perceptual units if they are present in the string. The data .also suggested that whole words can be used as functional visual units, although the extent of their use depends on contextual parameters such as knowledge that a word will be presented.     

Jeffrey Meets Kolmogorov

Journal of Philosophical Logic - Jeffrey conditionalization is a rule for updating degrees of belief in light of uncertain evidence. It is usually assumed that the partitions involved in Jeffrey...