The amplitude and phase of the second harmonic (15 Hz) of the electroretinographic responses to three different spatial frequency grating stimuli (0.25, 1 and 4 c/deg), reversed at 7.5 Hz, were studied i normal human subjects, before and 30 min after the systemic administration of three doses (0.071, 0.357 or 1.428 mg/kg) of a selective D2 blocker, l-sulpiride, to three populations of 18, 19, o...

OBJECTIVE To report the phenotype associated with the codon 172 RDS (gene for retinal degeneration slow) mutation in 11 separate families with an arginine-to-tryptophan substitution with common ancestry, and 1 family with an arginine-to-glutamine transition. PATIENTS Screening for RDS gene mutations was performed in 400 subjects with autosomal dominant retinal degeneration. Twelve families we...

BACKGROUND Osteo-odontokeratoprosthesis (OOKP) is an autologous transplantation procedure in which the cornea is replaced by an optical cylinder glued to a biological support. Patients undergoing OOKP surgery may develop a secondary glaucoma whose diagnosis, by means of standard diagnostic procedures, is often doubtful. METHODS In the present study pattern electroretinograms (PERGs), visual e...

PURPOSE To assess the effect of autosomal dominant optic atrophy (ADOA) on ON and OFF retinal ganglion cell (RGC) function by evaluating the ON and OFF components of the photopic negative response (PhNR). METHODS Twelve participants from six families with OPA1 ADOA and 16 age-matched controls were recruited. Electrophysiological assessment involved pattern ERGs (PERGs), focal (20°) and full-f...

PURPOSE To compare psychophysically determined spatial variations in photopic and scotopic sensitivity across the macula in patients with retinitis pigmentosa (RP) and normal visual acuity who manifest an abnormal high-density ring of fundus autofluorescence (AF). METHODS Eleven patients with a clinical diagnosis of RP were examined. All had rod-cone dystrophy (International Society for Clini...

In previous studies, we found a strong reduction in contrast perception and retinal contrast gain in patients with major depression, which normalized after remission of depression. We also identified a possible role of the dopaminergic system in this effect, because visual contrast perception depends on dopaminergic neurotransmission. Dopamine is also known to play an important role in the path...

This section of AJP includes physics education research ~PER! articles. It continues the editorial process that begun with the green PER Supplementary Issues to AJP published in July of 1999–2001. The PER section ~PERS! is a response to the tension between the long-standing policy of AJP not to publish research articles and the growing interest within the AAPT community in PER. Articles in the ...

Makalah ini meneliti kata kerja deiktik datang dan pergi sebagai spesifikasi ruang dalam bahasa Melayu. Kata yang juga dipanggil gerak merujuk kepada mana-mana menandakan arah bagi sesuatu entiti sedang bergerak seperti pergi. Justeru usaha untuk memahami komponen perg i, maka kajian mengambil 100 konkordans daripada Pangkalan Data Korpus Dewan Bahasa Pustaka. Dalam menganalisis , menggunakan M...

Purpose Our aim was to elaborate how on and off signals contribute to pattern ERGs and pattern visual evoked potentials (VEPs) by using pedestal patterns arising from incremental and decremental onset stimulation. Methods Pattern onset/offset ERGs and VEPs were produced by black and white checks of 60' side length and 88% spatial contrast appearing in a 16° field for 200 ms from white (110 cd...