A new visual-verbal saccade test: the development eye movement test (DEM).

The use of presently available clinical oculomotor tests of a visual-verbal format are limited because they do not evaluate automaticity of number naming. There is a significant relationship between automaticity of number naming and reading performance. Presented is a new oculomotor test that has a specific method to factor out the consequences of automaticity on oculomotor performance.

Clinical implications of parallel visual pathways.

Visual information travels from the retina to visual cortical areas along at least two parallel pathways. In this paper, anatomical and physiological evidence is presented to demonstrate the existence of, and trace these two pathways throughout the visual systems of the cat, primate, and human. Physiological and behavioral experiments are discussed which establish that these two pathways are differentially sensitive to stimuli that vary in spatial and temporal frequency.

Visual function and reading disability: an optometric viewpoint.

Recent research has identified a low-level transient visual system deficit in patients with reading disability. This deficit has been shown to have consequences on higher level perceptual and cognitive functions, including reading. This new information provides optometrists with a theoretical framework to expand the understanding of the relationship between vision and reading.

Experimental evidence for a transient system deficit in specific reading disability.

This paper summarizes the experimental evidence for a transient system deficit in specific reading disability. Differences have been found between controlled readers and specifically disabled readers in measurements of visible persistence, pattern contrast sensitivity and temporal or flicker contrast sensitivity. This transient system deficit was found in approximately 75% of the specifically reading disabled subjects tested.

How important are lens oxygen ratings? They are one of many performance factors.

To prevent corneal edema in most patients, contact lenses must transmit oxygen to the following minimum degree: (a) in daily wear, 24.1 x 10(-9) (cm x ml O2)/(s x ml x mm Hg), and (b) in extended wear, 34.3 x 10(-9) (cm x ml O2)/(s x ml x mm Hg).

The effects of a luminance-modulated background on the grating-evoked cortical potential in the cat.

Averaged grating-evoked cortical potentials were recorded from area 17 of awake cats. Peak latency of early components of the visual-evoked potential (VEP) response to stimulus onset increased as a function of spatial frequency, while amplitude tended to be largest at intermediate spatial frequencies. Latency increased and amplitude generally decreased to lower spatial-frequency stimuli (less than 0.

Optimum conditions for growth of cyanobacteria on solid media.

The colony forming ability of single cells or very short filaments of 7 strains of cyanobacteria was tested on media solidified by agar or by agar substitutes (Gel Gro or Gel Rite). In addition, the effect of various methods for preparation of agar media on colony forming ability was measured. High efficiency colony formation for most of the strains required that the agar be autoclaved separately from the salts in the medium.

Phosphate transport and arsenate resistance in the cyanobacterium Anabaena variabilis.

Cells of the cyanobacterium Anabaena variabilis starved for phosphate for 3 days took up phosphate at about 100 times the rate of unstarved cells. Kinetic data suggested that a new transport system had been induced by starvation for phosphate. The inducible phosphate transport system was quickly repressed by addition of Pi.

The apparent size of three-dimensional objects and their silhouettes: a solid-superiority effect.

A solid object looks larger than its outline or silhouette under many viewing conditions. This solid-superiority effect may result from the assimilation or confusion of visual contours within the projection of a three-dimensional object on the picture plane. An aspect of the Müller-Lyer illusion may also play a role.

Mechanosensory interneurons (MSIs) in the crayfish 6th abdominal ganglion are inhibited by activation of other MSIs.

1. Identified mechanosensory interneurons (MSIs) in the 6th abdominal ganglion of the crayfish Procambarus clarkii have been shown to inhibit other projecting MSIs. 2.

Age-related alterations in retinal function.

Age-related visual deficits that occur in the absence of recognized visual disease are frequently observed. Many of the optical factors contributing to these deficits have been delineated, but the contributing neurophysiological alterations have not been clearly defined. This investigation examined age-related variations in the retinal and cortical processing of visual information.