The Glare Effect Does Not Give Rise to a Longer-Lasting Afterimage

Hongjing Lu; Daniele Zavagno; Zili Liu

doi:10.1068/p5484

The Glare Effect Does Not Give Rise to a Longer-Lasting Afterimage

Perception ◽

10.1068/p5484 ◽

2006 ◽

Vol 35 (5) ◽

pp. 701-707 ◽

Cited By ~ 9

Author(s):

Hongjing Lu ◽

Daniele Zavagno ◽

Zili Liu

Keyword(s):

Low Level ◽

Physical Stimuli ◽

Glare Effect

The glare effect is an illusion in which a region appears self-luminous when flanked by gradients that decrease in luminance with distance from the region (Zavagno, 1999 Perception28 835–838). This region also appears brighter than a surface of the same luminance. We investigated, using the paradigm of afterimages, whether a low-level mechanism at the level of the retina or LGN could account for this apparent brighter sensation. We first replicated the result from the literature that brighter and longer-lasting physical stimuli generate longer-lasting afterimages. We then compared the glare-effect stimuli with their counterpart controls, and found that the glare-effect stimuli did not give rise to longer-lasting afterimages. This suggests that the apparent brighter sensation of the glare effect is not due to a retinal or LGN mechanism, but must have a cortical origin.

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THE EFFECTS OF PHYSICAL STIMULI ON THE LARVAL STAGE OF TERRANOVA DECIPIENS: III. ELECTROMAGNETIC SPECTRUM AND GALVANOTAXIS

Canadian Journal of Zoology ◽

10.1139/z63-022 ◽

1963 ◽

Vol 41 (2) ◽

pp. 197-217 ◽

Cited By ~ 3

Author(s):

Keith Ronald

Keyword(s):

Latent Period ◽

Direct Current ◽

Larval Stage ◽

Fish Muscle ◽

Electromagnetic Spectrum ◽

Light Radiation ◽

Directional Response ◽

Low Level ◽

Physical Stimuli ◽

Directional Stimulus

Various frequencies in the range of 25.9 kc to approximately 100 mmmc were used as a source of stimuli to the larval stage of the nematode Terranova decipiens. Larvae exposed to 650 kc ultrasound were killed in 4 minutes, while those exposed to 25.9 and 1000 kc were killed in 30 and 270 minutes respectively. The larvae were not affected by radiation produced either in the radio- or the micro-wave frequencies. Light radiation of less than 280 mμ had no effect on the nematode, while fish muscle insulated the larvae from the limited effects of radiations between 253.7 to 900 mμ. The larvae showed no photo tactic response. When exposed to 4 million roentgen equivalent physical, the larvae died immediately (LD50); however, after a latent period of 288 hours a much lower dose (400,000 rep) will bring about death. The larvae were stimulated by low-level direct current applied intermittently, but exhibited no directional response to any level of alternating or direct current. The low resistance offered by the fish muscle habitat of the nematode excludes any application of directional stimulus.

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Tryptophan-Niacin Metabolism in Rat with Puromycin Aminonucleoside-Induced Nephrosis

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831.76.1.28 ◽

2006 ◽

Vol 76 (1) ◽

pp. 28-33 ◽

Cited By ~ 7

Author(s):

Yukari Egashira ◽

Shin Nagaki ◽

Hiroo Sanada

Keyword(s):

Body Weight ◽

Urinary Excretion ◽

Enzyme Activities ◽

Treated Group ◽

Control Group ◽

Puromycin Aminonucleoside ◽

Low Level ◽

Key Enzyme

We investigated the change of tryptophan-niacin metabolism in rats with puromycin aminonucleoside PAN-induced nephrosis, the mechanisms responsible for their change of urinary excretion of nicotinamide and its metabolites, and the role of the kidney in tryptophan-niacin conversion. PAN-treated rats were intraperitoneally injected once with a 1.0% (w/v) solution of PAN at a dose of 100 mg/kg body weight. The collection of 24-hour urine was conducted 8 days after PAN injection. Daily urinary excretion of nicotinamide and its metabolites, liver and blood NAD, and key enzyme activities of tryptophan-niacin metabolism were determined. In PAN-treated rats, the sum of urinary excretion of nicotinamide and its metabolites was significantly lower compared with controls. The kidneyα-amino-β-carboxymuconate-ε-semialdehyde decarboxylase (ACMSD) activity in the PAN-treated group was significantly decreased by 50%, compared with the control group. Although kidney ACMSD activity was reduced, the conversion of tryptophan to niacin tended to be lower in the PAN-treated rats. A decrease in urinary excretion of niacin and the conversion of tryptophan to niacin in nephrotic rats may contribute to a low level of blood tryptophan. The role of kidney ACMSD activity may be minimal concerning tryptophan-niacin conversion under this experimental condition.

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