PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 1199682

Evoked responses induced by random polygonal pattern presentation.

Z Bohdanecký·T Radil-Weiss·J Spunda·V Bozkov
View original source ↗Export metadata ↓

Abstract

An experiment is described which was designated to test the assumption that visual EEG evoked response waveshapes in human beings may be influenced by the presentation of random shapes differing in level of their similarity and in angular position. A clear-cut difference between the blank flash and the patterns which might be determined by the presence of contours was observed. However, neither differences in EEG evoked responses referred to the shape nor to the angular position of the polygons were found.

Explore related subjects

ElectroencephalographyEvoked PotentialsForm PerceptionHumansPattern Recognition, VisualVisual CortexVisual FieldsJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Z Bohdanecký, T Radil-Weiss, J Spunda, V Bozkov. 1975. Evoked responses induced by random polygonal pattern presentation.. https://pubmed.ncbi.nlm.nih.gov/1199682/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed1992

Visual acuity of low- and high-risk neonates and acuity development during the first year.

Binocular grating acuity of 65 neonates was measured using Teller acuity cards. At the time of testing, age corrected for prematurity ranged from -3 weeks to 2 weeks. On the basis of clinical data, serial ultrasound scans and EEG recording newborns were divided into 4 subgroups: fullterm low-risk (FLR, n = 22); preterm low-risk (PLR, n = 20); preterm medium-risk (PMR, n = 9) and preterm high-risk (PHR, n = 14). Mean visual acuity of PLR infants (0.86 cy/deg; S.D. 0.34 oct) was not significantly different from that of FLR newborns (0.80 cy/deg; S.D. 0.71 oct); the lower variability of the PLR infants might possibly be caused by their longer postnatal experience. Within the preterm groups, mean visual acuity of PLR newborns was found to be significantly higher than that of PMR (0.73 cy/deg; S.D. 0.26 oct) and PHR infants (0.73 cy/deg; S.D. 0.35 oct). This difference can not be explained by dissimilarities in postnatal or corrected age. Brain impairment, as documented by US scans and EEG recording could account for these findings. Longitudinal data are needed in order to substantiate these findings and correlate them with later neurological and neuro-imaging outcome. Preliminary results of an ongoing longitudinal study suggest acuity development of most, but not all, PHR infants, in whom a cystic-periventricular leukomalacia had been diagnosed, to be worse than that of low- and medium-risk infants.

Electroencephalography↗
PubMed1992

Clinical value of polysomnography.

Polysomnography is used increasingly to investigate patients with possible sleep apnoea/hypopnoea syndrome (SAHS), but it has not been assessed critically. We thus examined prospectively the value of electrophysiological and respiratory monitoring in 200 consecutive adults (163 men, 37 women; mean [SD] age 50 [13] years) having polysomnography. At polysomnography, 91 patients had SAHS (greater than 15 apnoeas + hypopnoeas [A + H] per h asleep) and 11 had periodic limb-movement disorder. Recording sleep electrophysiologically was of no diagnostic value and SAHS could be as accurately defined by A + H per time in bed as by A + H per time asleep. 66% of patients with SAHS could be diagnosed with oximetry alone, but many of the undiagnosed patients had moderately severe SAHS and benefited from treatment. Neurophysiological sleep recording is unnecessary and oximetry alone is of limited value in the overnight investigation of patients suspected of having SAHS.

Electroencephalography↗