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Results 551 - 600 of 1078
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Courage M L - - 1997
The increased viability of extremely low birth weight (ELBW) infants (those weighing less than 1,000 g) and the associated increased risk of visual impairment has highlighted the need for reliable indices of visual functioning for this population. By use of the Teller Acuity Cards, we assessed grating visual acuity in ...
Tellinghuisen D J - - 1997
Two experiments investigated the role of distractor characteristics and type of object-directed attention on infants' distraction latencies during object exploration. In Experiment 1, 7- and 10-month-old infants' distraction latency was a function of both attention and the characteristics of the distractors. Infants took longer to turn toward distractors during focused ...
Dougherty T M - - 1997
A longitudinal study investigated the relation between infant expectations and reaction time (RT) and childhood IQ and RT. Measures of visual anticipation and visual RT were taken at 3.5 months and 4 years of age. In addition, manual RT and verbal and performance IQ were measured at 4 years of ...
Clarke M P - - 1997
The results of flash visual evoked potentials (VEPs) in 44 infants blind or severely visually impaired from non-ocular causes are presented, and related to the subsequent visual outcome. Ocular causes of visual impairment were excluded by clinical examination and electroretinography. Using a 2 x 2 contingency table, a significant association ...
Hafström M - - 1997
A new method for automatic analysis of non-nutritive sucking in newborn infants is described, which uses a specially designed computer program that analyses an analogue signal obtained from a pressure transducer inside a pacifier. Validation is done with four independent methods: electromyogram, visual identification, control of the automatic treatment and ...
Ekert P G - - 1997
Visual evoked potentials (VEPs) have proved to be accurate predictors of outcome in term infants with hypoxic-ischemic encephalopathy. Parallels between term asphyxia and hypoxic-ischemic injury in the preterm brain suggested the hypothesis that VEPs may predict the development of periventricular leukomalacia (PVL) and later cerebral palsy. 123 infants less than ...
Aitkin L - - 1996
The development of hearing was studied in the Northern Quoll, a nocturnal marsupial carnivore whose young are born into a pouch in an immature state after about 21 days in utero. Startle responses to noise bursts of 105 dB sound pressure level first appeared at 60 days after arrival in ...
Snir M - - 1996
A 2-month-old female infant with intractable congenital glaucoma and diffuse corneal opacification underwent trabeculectomy with 5-fluorouracil (5-FU) injection in both eyes followed by penetrating keratoplasty (PKP) combined with partial cyclocryotherapy in the right eye. The latter procedure was undertaken despite the B-scan ultrasonographic finding of extensive optic disc cupping in ...
Fujii M - - 1996
It is difficult to estimate the accurate onset of symptoms clinically resulting from Chiari II malformation. Brainstem auditory evoked potentials (BAEPs) may be a useful method in the selection of potential candidates for surgery. We studied 153 BAEPs in 131 asymptomatic infants under 6 months of age with meningomyelocele (MMC). ...
Lewkowicz D J - - 1996
Using a habituation/test procedure, the author investigated adults' and infants' perception of auditory-visual temporal synchrony. Participants were familiarized with a bouncing green disk and a sound that occurred each time the disk bounced. Then, they were given a series of asynchrony test trials where the sound occurred either before or ...
Rovee-Collier C - - 1996
The effects of set size and novelty on visual pop-out in 6-month-old infants was assessed in a perceptual-identification (memory reactivation) paradigm in which infants, trained and tested in their own homes, viewed a mobile containing a unique novel or familiar object amidst different numbers of familiar or novel distractors, respectively. ...
Adams R J - - 1996
A recently developed psychophysical "card" technique was used to evaluate monocular contrast sensitivity in ninety 3-, 6-, 12-, 24-, and 36-month-old human infants. Results showed that for 3-, 6-, 24-, and 36-month-olds, monocular contrast sensitivity functions were very similar to binocular contrast sensitivity functions estimated in a previous experiment. However, ...
Katbamna B - - 1996
We evaluated the effect of electrode montage on the spectrum of the infant auditory brainstem response (ABR). Spectral profiles of ipsilateral, contralateral, noncephalic, and horizontal recordings obtained in response to slow and fast repetition rates and at low and high stimulus intensities were also evaluated. Findings indicate that the spectrum ...
Eldredge L - - 1996
Bilateral ABRs were recorded from 452 infants 32-45 weeks conceptional age. Differences in laterality, gender and appropriateness for gestational age were investigated in order to increase our understanding of developmental processes in early life. Rate effects were also studied in a subsample of infants (145 ears). All subjects were free ...
Malcuit G - - 1996
In experiments on infant attention, the sudden presentation of a stimulus elicits an orienting response (OR). Its persisting presence then reinforces its visual exploration. When subsequently projected, this stimulus comes to signal the availability of something to look at. The aim of the present study was to sort out the ...
Harland R E - - 1996
This study examined the relationship between birth risk factors and sensory capacity in 1245 young adults (mean age = 19.9 years). Nine birth risk factors were included (long labour, breech birth, breathing difficulty, instrument delivery, Caesarian delivery, multiple birth, premature birth, low birth weight, and high-risk birth order) and six ...
Fledelius H C - - 1996
An ophthalmic follow-up comprised 88 children aged 7-10 years who had regular screening for retinopathy of prematurity (ROP) after their pre-term delivery 1982-84. Mean values of birth weight and gestational age in the 88 were 1467 g and 31 weeks. Out of 28 with early evidence of ROP four had ...
Hadders-Algra M - - 1996
1. The present study addressed the question of whether daily balance training can affect the development of postural adjustments in sitting infants. 2. Postural responses during sitting on a moveable platform were assessed in twenty healthy infants at 5-6, 7-8 and 9-10 months of age. Multiple surface EMGs and kinematics ...
Birch E - - 1996
Dynamic random dot fusion, stereopsis and stereoacuity were evaluated in 149 healthy, fullterm infants, using both forced-choice preferential looking (FPL) and steady-state visual evoked potential (VEP) protocols. Few infants aged 2-3 months demonstrated fusion or stereopsis in either the FPL or VEP protocol; most infants aged 5 months and older ...
Lambert S R - - 1996
Cataracts are one of the most treatable causes of visual impairment during infancy. Recent epidemiological studies have shown that they have a prevalence of 1.2 to 6.0 cases per 10,000 infants. The morphology of infantile cataracts can be helpful in establishing their etiology and prognosis. Early surgery and optical correction ...
Frick J E - - 1996
In 5 experiments, 4-month-old infants were tested for their ability to recognize degraded visual targets as a function of individual differences in fixation duration. Targets were degraded by removing 10% of the total contour either from vertices (vertex-absent) or from midsegments (vertex-present). Both qualitative and quantitative differences were found in ...
Gregory N G - - 1996
Sixty-one calves were electrically stunned with 100-250 V currents (103-1806 mA) and the prevalence and duration of insensibility was assessed from their physical behaviour, the presence of epileptiform activity in their electrocorticograms, and the absence of visual evoked responses in their electrocorticograms. A current applied at 100 V across the ...
Eken P - - 1996
A longitudinal prospective follow-up study looking at the correlation between haemorrhagic-ischaemic lesions on neonatal cranial ultrasound (US) and the development of cerebral visual impairment (CVI) in infancy resulted in the detection of nine infants with severe visual impairment, which was not due to opthalmological abnormalities. Extensive cystic leukomalacia proved to ...
Braddick O - - 1996
A variety of behavioural and electrophysiological studies agree that the onset of functional binocular interaction in human visual cortex normally occurs between 10 and 16 weeks of age. Measures of sensitivity to binocular correlation and to disparity agree closely, and behavioural and visual evoked potential measures on the same infant ...
Dobkins K R - - 1996
In order to investigate the presence of directionally selective mechanisms in 3-month-old infants, we employed a summation-near-threshold paradigm previously developed for studies of adult vision (Levinson & Sekuler, 1975 Journal of Physiology (London), 250, 347-366); Watson, Thompson, Murphy & Nachmias, 1980 Vision Research, 20, 341-347). The degree of contrast summation ...
Kiorpes L - - 1996
Interpretation of measurements of visual performance in infants must be based on knowledge of the locus of highest sensitivity in the infant retina. While we know that adult contrast sensitivity and spatial resolution is highest at the fovea, recent anatomical data show that the infant fovea is relatively immature. We ...
Brockway P D - - 1996
The postnatal development of atrial natriuretic peptide (ANP) stimulus-secretion coupling was examined in rabbit ileum. A positive correlation between age and ANP-induced secretory responsiveness was observed. The short circuit current (Isc) response in 14-day animals was significantly (p < 0.05) less than that seen in 21-day, 28-day and adult animals. ...
Brown A M - - 1995
Infant color vision is poor, and most psychophysical experiments agree that infant color vision emerges between ages 3 weeks and 3 months. Presumably, the color vision of infants is poor during the months immediately after it has emerged. We have tested two alternative explanations for the poor color vision of ...
Nozza R J - - 1995
Estimates of behavioral thresholds of infants are elevated relative to those of adults. Explanations for the differences include auditory sensory factors and non-sensory factors, but no direct estimates of the relative contributions of these two factors have been made. In this investigation, thresholds in quiet and in increasing levels of ...
Carruthers J D - - 1995
In the past year, new work on sensory testing in preverbal infants has expanded our knowledge in three areas: 1) visual acuity testing in infants in varying levels of illumination; 2) visual evoked cortical potential-evidence for binocular function in infantile esotropia; and 3) a new time-efficient method to evaluate color ...
Leaf A A - - 1995
Electroretinograms (ERGs) and visual evoked potentials (VEPs) to flash stimulation were recorded from 51 infants (gestational age 26 to 42 weeks; post-conceptional age (PCA) 31 to 47 weeks) to give cross-sectional data on the maturation of these responses. Sequential recordings were taken from a separate group of 24 preterm infants ...
Skoczenski A M - - 1995
Vernier acuity in human infants is more than two orders of magnitude poorer than in adults and does not appear to reach adult levels until well beyond the first postnatal year. One source of these developmental differences in vernier acuity may be the presence of levels of intrinsic blur that ...
Tsuneishi S - - 1995
To establish normal values for flash visual evoked potentials (VEPs) in the preterm period, we analyzed 356 records from 63 neurologically normal infants (26-35 weeks gestation) followed longitudinally. Using both sleep and drowsy state recording within the same session and a mean of 5.7 weekly recording sessions per infant, we ...
Pierson L L - - 1995
The Auditory Brainstem Response (ABR) was recorded from fetal sheep in utero between gestational ages of 111 days and 136 days (Normal gestation is 145 days). The ABR was detected at 111 days gestation (dGA) and morphology of the waveform improved rapidly from 116 to 123 dGA. At 123 dGA, ...
Bargones J Y - - 1995
Psychometric functions are described for individual 6- to 9-month-old infants and for individual adults for auditory detection of repeated, long- and short-duration tone bursts in quiet and for single, long-duration tone bursts in quiet and in noise. In general, infant psychometric functions have reduced upper asymptotes, shallower slopes, and poorer ...
Breton M E - - 1995
PURPOSE: To describe and analyze developmental change from birth through maturity of human electroretinogram (ERG) response, especially in terms of rod phototransduction as represented in the ERG a-wave. METHODS: Electroretinograms were recorded from 16 human infants from 5 to 270 days of age, two children 1.9 and 3.4 years of ...
Hansen R M - - 1995
We tested the hypothesis that the dark-adapted sensitivity of the near central retina is lower than that of peripheral retina in 10-week-old infants. A spatial two alternative forced-choice psychophysical method was used to estimate the threshold for 2-deg spots presented 10 deg and 30 deg from the center of a ...
Bieber M L - - 1995
Spectral efficiency functions based on heterochromatic flicker photometry (HFP) were measured for three adults and 42 infants using a rapid visually-evoked potential (VEP) method. A 5 degrees-diameter, broadband standard (0.6 cd/m2) was presented in square-wave counterphase (15 Hz) with one of 13 monochromatic lights (420-660 nm; 20 nm steps). The ...
Abdala C - - 1995
The results of previous research reports have led some investigators to hypothesize that frequency contribution to the infant click-evoked auditory brain-stem response (ABR) is low-frequency dominated and derived primarily from the apical cochlea. This is in contrast to latency and morphology of the adult click-evoked ABR which reflects contributions from ...
Luna B - - 1995
Grating acuity and visual fields were assessed in 66 children who had had perinatal asphyxia (ASPH). Also tested were 41 healthy preterm children (H-PT). Subjects were tested at birth to one month, and four, nine, 12, 17, 24, 30 and 36 months corrected age. The mean acuity scores of the ...
Preisler G M - - 1995
Results from two longitudinal studies of blind infant--sighted mother and of deaf infant-hearing mother/deaf mother interaction, are summarized in this paper. The aim is to shed light on the role of visual and auditory stimulation in the development of communication. Video-recorded interactions taken during infancy were transcribed in a systematic, ...
Hansen R M - - 1995
Dark-adapted adults' electroretinographic b-wave thresholds are approximately 2 log units below a-wave thresholds and approximately 3 log units above the perceptual threshold, and their perceptual and the visually evoked cortical potential (VEP) thresholds are similar. Dark-adapted infants' scotopic a- and b-wave thresholds for full-field stimuli are both about 0.5 log ...
Uauy-Dagach R - - 1995
There is now clear evidence that dietary supplementation of omega-3 fatty acid is essential for normal eye and brain development. Corn oil-based diets induce omega-3 deficiency in preterm infants, affecting retinal responses to light, cortical visual evoked potentials, and behavioral measures of visual acuity. Preterm infants require docosahexanoic acid (DHA) ...
Roy M S - - 1995
The purpose of this study was to evaluate the visual development of preterm infants from 1 to 6 mo of age, using the pattern visual evoked potentials (VEP) in response to three check sizes: 60, 30, and 15 min of arc. Pattern VEP were recorded in 24 full-term and 24 ...
Mukai Y - - 1995
To find how larval fish sense mechanical stimuli via their free neuromasts, we examined morphological changes in free neuromasts in the larval willow shiner, Gnathopogon elongatus caerulescens. Free neuromasts were found on the body surface of newly hatched larvae and their number increased on both the head and trunk with ...
Hartmann E E - - 1995
Studies of sensory and perceptual abilities in infants require creative, innovative techniques. Although the young infant's response repertoire may appear limited to the naive individual, a number of highly refined procedures have been developed and implemented with these non-verbal humans over the last twenty years. The most successful protocols for ...
Schaal B - - 1995
Two-day-old newborns were videotaped during a double-choice test contrasting the odours of their amniotic fluid (AF) and of a control stimulus. To control for early motor asymmetries, the lateral position of both stimuli was balanced both between and within subjects. On average, neonates oriented their nose for a significantly longer ...
Slater A - - 1995
In recent years it has been demonstrated that cognitive development from infancy to later childhood displays some degree of (correlational) continuity. Studies that have demonstrated this continuity are reviewed, focusing on measures of visual information processing, means-ends problem-solving and other cognitive indices of infant performance. Models of continuity are described ...
Sinskey R M - - 1994
A cataract extraction and primary capsulotomy with intraocular lens (IOL) implantation was performed on a 17-day-old infant with a monocular mature congenital cataract. The IOL power, calculated at the time of surgery, was undercorrected to compensate for the growth of the eyeball. Two additional surgical procedures were required to resolve ...
Yu X H - - 1994
Adaptive implementation of an optimal time-varying filter (TVF) for evoked potential (EP) estimation is addressed in this paper. A data-adaptive scheme is used, which converges asymptotically to the optimal TVF solution. Two basic adaptive TVF's (ATVF's) are first introduced, namely least mean square (LMS) ATVF and recursive least-squares (RLS) ATVF. ...
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