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Results 501 - 550 of 1078
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Mercuri E - - 1998
The onset and maturation of visual cortical mechanisms can be recorded by using steady-state visual evoked potentials. The aim of this study was to evaluate and compare orientation-reversal (OR) and phase-reversal (PH) VEP as indicators of the maturation of cortical function in a population of fullterm infants with brain lesions ...
Westall C A - - 1998
PURPOSE: To investigate the correlation between directional asymmetry in ocular responses to monocularly viewed optokinetic stimuli (monocular optokinetic nystagmus, MOKN) and sensory fusion in infants and toddlers with early-onset esotropia. METHODS: Subjects were 14 infants and toddlers with early-onset esotropia (7-26 months old; median, 10 months), and 16 with no ...
Csibra G - - 1998
Neural correlates of saccade planning in 6-month-old infants were investigated by high-density event-related potentials. Subjects made saccades to a target stimulus following a time gap from fixation stimulus offset (gap trials) or with the fixation stimulus still present (overlap trials). Like adults, infants were slower to make a saccade to ...
Nelson C A - - 1998
The present study sought to compare adult and infant ERP responses in analogous tests of visual recognition memory. Adults were tested under two test conditions, in which they were given either explicit instructions to respond to a previously-seen stimulus, or no instructions. Testing in both conditions took place after either ...
Karrer J H - - 1998
Development of cerebral inhibitory processes among individuals with Down syndrome (DS) may be delayed at an early age. In support of this hypothesis, sensory-evoked potentials (EPs) and event-related brain potentials (ERPs) have previously delineated altered habituation to stimuli among infants with DS. The purpose of the current study was to ...
Ahn MO - - 1998
> Objective: To describe the perinatal characteristics of neurologically impaired infants with normal intrapartum fetal heart rate (FHR) patterns. Methods: In a registry of 300 neurologically impaired singleton term infants, a retrospective chart review was undertaken to analyze those patients with a normal intrapartum FHR pattern, i.e. reactive FHR pattern ...
Sireteanu RH - - 1998
Visual acuity was measured in infants with the forced-choice preferential looking technique, using videotaped material from live observations. There was excellent agreement between the acuity values estimated with the two procedures, suggesting that observations on videotaped material can replace "live" observations in the estimation of visual functions in infancy.
Bieber M L - - 1998
Field sensitivities were measured under conditions of M- and L-cone isolation for seven infants (8-12 weeks-old) and two adults, using silent-substitution and the visually evoked potential (VEP). The efficacy of the receptor-isolation conditions were first verified by measuring psychophysical and VEP-derived action spectra from two color-normal adults under conditions of ...
Meek J H - - 1998
This study presents the first measurements using near infrared spectroscopy of changes in regional hemodynamics as a response to a visual stimulus in awake infants. Ten infants aged 3 d to 14 wk viewed a checkerboard with a 5-Hz pattern reversal. The emitter and detector (optodes) of a near infrared ...
Rose S A - - 1998
The present study demonstrated that individual differences in cross-modal transfer showed continuity over a 10-year span. Tactual-visual tasks, requiring visual recognition of shapes that had previously been felt but not seen, were given to full-term and preterm children at 2 ages, 1 and 11 years. Cross-modal performance showed a left-hand ...
Onat T - - 1998
To establish the incidence and course of right ventricular (RV) conduction delay during the regression of right ventricular dominance, 12 serial ECGs were recorded at regular intervals until age 36 months in a cohort of 43 normal neonates. Additionally, ECGs were recorded similarly in 6 infants from the age of ...
Bianchi P E - - 1998
Two infants who presented with wide-amplitude and high-frequency nystagmus and lack of visual awareness in the first 3 months of life were studied. No ocular abnormalities were found. Neurodevelopmental examination, visual evoked potentials and electroretinograms were normal. One infant underwent MRI which resulted in normal findings. Two months later both ...
Dannemiller J L - - 1998
Four experiments are reported on exogenous (stimulus-driven) orienting in 3.5-month-old infants. A small moving bar embedded in a field of static bars was used to draw the infant's attention to one side of the display or the other. The bars could be either red or green. In all four of ...
Wentworth N - - 1998
The microdevelopment of infants' visual expectations was examined by analysis of the eye movements that 80 three-month-old human infants made during interstimulus intervals (ISIs) of an alternating picture sequence. For comparison, identical eye movement data were gathered from 10 infants who watched an irregular sequence. Shifts during ISIs were exhibited ...
McCulloch D L - - 1998
The infant patient presents a challenge to the optometrist who must structure an examination within the infant's limited capabilities and then manage a rapidly developing visual system. The present paper provides an overview of infant visual development and the visually guided behaviours expected during normal development. Techniques for assessing vision ...
Koester L S - - 1998
The authors examine the effects that results when 9-month-old deaf and hearing infants break eye contact during face-to-face interactions with their deaf or hearing mothers. Of particular interest are mothers' responses when their infant looks away, and mothers' degree of success at regaining visual attention by using active bids in ...
Phelan JP - - 1998
>Objective: To describe the fetal heart rate (FHR) patterns of 300 term brain-damaged infants.Methods: The fetal monitor strips of 300 singleton term neurologically impaired neonates were retrospectively analyzed.Results: Of the 300 infants, the admission FHR patterns were: reactive, 152 (51%); nonreactive, 135 (45%); bradycardia, 9 (3%); or unclassifiable, 4 (1%). ...
Birch E E - - 1998
PURPOSE: The overall goal was to develop a simple test of random dot stereoacuity that can be used during the first 24 months of life to measure sensory outcomes following treatment of ophthalmopediatric disorders, both in the context of clinical trials and in the context of clinical management. METHODS: A ...
Skoczenski A M - - 1998
Visual contrast sensitivity is poor in newborn human infants, but improves rapidly to approach adult levels by 8 months of age. During this period, infant sensitivity can be limited by physical factors affecting photon capture, such as eye size and photoreceptor density. Here we show that infant visual sensitivity is ...
Quiñónez R E - - 1998
The purpose of this investigation was to determine what types of changes occur in the distortion product otoacoustic emission (DPE) latency with increasing postconceptual age. These DPE latency changes were then described in relation to developmental changes in conductive and cochlear mechanisms in the neonate. Longitudinal DPE latency measurements were ...
Sawaguchi K - - 1998
Waveform analyses of flash visual evoked potentials (VEPs) in neurologically normal preterm infants (postconceptional age 31-42 weeks) were performed using an autoregressive moving average (ARMA) model to interpret the evoked potentials as dynamic high-order responses to natural and experimental stimulation. Averaged VEP waveforms obtained were decomposed into 7-11 component impulse ...
Corkum V - - 1998
Two experiments examined the origins of joint visual attention with a training procedure. In Experiment 1, infants aged 6-11 months were tested for a gaze-following (joint visual attention) response under feedback and no feedback conditions. In Experiment 2, infants 8-9 months received feedback for either following the experimenter's gaze (natural ...
Bertenthal B I - - 1997
In this investigation of developmental changes in the coordination of perceived optical flow and postural responses, 4 age groups of infants (5-, 7-, 9-, and 13-month-olds) were tested while seated on a force plate in a "moving room." During each trial the walls oscillated in an anteroposterior direction for 12 ...
Richards J E - - 1997
Visual fixation in infants from 3 to 6 months of age was examined for its fit to the theory of "attentional inertia." This theory posits that during the progression of a look there is increasing attention toward the stimulus and an "inertia" to continue looking. An extended audiovisual stimulus was ...
Gilmore R O - - 1997
The nature of the spatial representations that underlie simple visually guided actions early in life were investigated through the application of a 'double-step' saccade paradigm to 3- and 7-month-old infants. Saccades in the older infants, like those observed in adults, were executed within body-centered spatial coordinates that take into account ...
Colombo J - - 1997
Although individual differences in visual habituation have long been interpreted in terms of processes derived from comparator theory, research over the last decade has suggested that arousal or arousability as manifest in sensitization may contribute to infants' attentional profiles, and thus, to individual differences in those profiles. We explored this ...
Boivin X - - 1997
We studied the ability of 32 lambs reared artificially in groups of four to discriminate between their shepherd and an unknown shepherd. Half of the lambs were bottle fed in isolation by one shepherd during the first 3 wk. The other half was fed alternately by three shepherds. Lambs had ...
Dobkins K R - - 1997
In order to investigate the development of temporal contrast sensitivity functions (tCSFs) for chromatic (red/green) stimuli, we obtained chromatic contrast thresholds from 3-month-old infants and adults using behavioral techniques. Stimuli were moving or counterphase-reversing sinusoidal gratings of 0.25 c/deg. Five temporal frequencies were used: 0.7, 2.1, 5.6, 11 and 17 ...
Fang L L - - 1997
PURPOSE: Lessened acuity for oblique contours as compared with horizontal and vertical contours, the oblique effect, is characteristic of humans and animals. The magnitude of the oblique effect in humans varies with ethnic origin. Three experiments were performed to determine the source and extent of this variation in Chinese and ...
Brown A M - - 1997
BACKGROUND: Vernier acuity was measured longitudinally for comparison with published results on early stereopsis development. METHODS: Thirty-seven human infants were tested using forced-choice preferential looking. These included 29 pilot infants (9 or 12 weeks of age) and eight infants tested longitudinally (9 weeks to 11 to 15 weeks of age). ...
Mercuri E - - 1997
AIM: To examine the effects of early lesions in the visual pathway on visual function; and to identify early prognostic indicators of visual abnormalities. METHODS: The visual function of 37 infants with perinatal brain lesions on magnetic resonance imaging was assessed using behavioural and electrophysiological variables. RESULTS: Normal visual behaviour ...
Quiñónez R E - - 1997
The purposes of this investigation were to determine 1) if auditory peripheral maturity is present in the newborn; 2) if not, at what age maturational changes occur in the peripheral auditory system from preterm to full-term; and 3) how results of tests used to identify auditory dysfunction in neonates, such ...
Ottar W L - - 1997
An accurate visual acuity assessment is an important part of the ophthalmic examination. Each patient needs his or her vision assessed whether an adult, a baby, or a child. The purpose of this article is to review some of the testing methods used to assess vision in the less than ...
Boller K - - 1997
The effect of passively exposing infants to visual information in a sensory preconditioning paradigm was assessed in five experiments with seventy-eight 6-month-olds. In the basic paradigm, infants were simultaneously exposed to two contexts (S1 and S2), trained in one of them (S1), and tested in the other (S2). Infants learned ...
Riddell P M - - 1997
PURPOSE: This study compares the development of acuity in the same infants during one testing session using Teller acuity cards (TAC) and sweep visual evoked potentials (sVEP). We asked whether different testing methods in two centers would produce different developmental time courses. METHODS: Forty-eight infants were tested in two centers. ...
Jacobs M - - 1997
PURPOSE: We set out to assess the development of pursuit eye movements in normal infants in an objective, longitudinal fashion. We asked whether smooth pursuit (SP) was present under 2 months of age and how the saccade ratio changed with increasing infant age. METHODS: Smooth pursuit was recorded longitudinally from ...
Littleford R C - - 1997
In vivo nailfold capillary microscopy was performed on 10 men with vibration white finger (VWF) and 10 age-matched male controls. The observed nailfold capillaries required adaptation of Maricq's classifications and addition of new morphological scoring systems. These new classifications produced numerical scores for assessing capillary: dropout, tortuosity, elongation, visualization of ...
Rasengane T A - - 1997
The time course for the development of the temporal contrast sensitivity function in humans is uncertain. Some studies indicate that temporal contrast sensitivity is immature in infants. However, earlier work suggests that critical flicker fusion is adult-like by 2 months. We traced the development of temporal contrast sensitivity to uniform ...
Blumenthal T D - - 1997
In the present study, I investigated the effect of stimulus repetition on human startle eyeblink reflex inhibition (PPI) by a prepulse. Participants were assigned to one of three groups (n = 14 each), in which they received 18 trials of (a) noise startle stimuli presented alone or preceded by 1000-Hz ...
Reinecke R D - - 1997
Current concepts of idiopathic infantile nystagmus are summarized, with special attention to treatment and differential diagnosis of this condition. Advantages of the Anderson procedure over the Kestenbaum procedure are suggested for head turn associated with this condition, and the need for further studies is acknowledged. The importance of the extended ...
Currie D C - - 1997
We investigated the roles that blur, proximity and vergence cues play in the development of accommodation. Accommodative responses to targets incorporating one or more of these cues were measured for four adults and eight infants at 1.5 and 3 months of age using eccentric photorefraction. Adults showed accurate accommodation to ...
Mercuri E - - 1997
Thirty-one full term infants with hypoxic-ischaemic encephalopathy (HIE) were studied with a battery of tests designed to evaluate visual function in infancy and with serial MRI. Their age ranged between 5 and 31 months. The aim of the study was to evaluate whether the degree of HIE or the site ...
Richards J E - - 1997
The effect of attention to a focal stimulus on 3- to 6-month-old infants' peripheral stimulus localization was examined. Fixation was engaged on a central visual stimulus, and a stimulus was presented in the periphery after discrete time intervals (0 to 12 s) or until changes in heart rate (HR) occurred. ...
van Zalen-Sprock R M - - 1997
We investigated the development of the skeleton in the embryonic and early fetal period both with ultrasonography and radiology. Eight normal embryos/fetuses were studied weekly with real-time transvaginal sonography between 8 and 16 weeks of gestation to establish the ultrasonographic characteristics of normal ossification. Additionally, ossification was studied in radiographs ...
Kennedy K A - - 1997
AIMS: To examine the effects of light on retinal development and function in preterm infants as measured by the electroretinogram (ERG). Secondary outcomes included visual acuity testing, the incidence of retinopathy of prematurity, and general wellbeing, reflected in feeding tolerance, rate of weight gain, and length of hospital stay. METHODS: ...
Jankowski J J - - 1997
In this study, the relationships between the length, number, and distribution of looks were investigated. To this end, 5-, 7-, and 9-month-old infants were familiarized for 24 or 36 s with two identical geometric forms and tested with a novel form paired with the familiar one. The distribution of individual ...
Mix K S - - 1997
This article examines an important finding from the literature on infant numerical competence. The finding, reported by P. Starkey, E. S. Spelke, and R. Gelman (1990), was that infants looked longer toward a visual display that was equal in number to an auditory set. In Experiment 1, when the procedures ...
Teller D Y - - 1997
The purpose of the present study was to investigate the capacity of infants to code the direction of motion of moving tritan-modulated gratings. Infant and adult subjects were tested with 0.2 c/d sinusoidal gratings moving at a speed of 20 deg/sec. Three conditions were tested: luminance-modulated gratings, tritan-modulated gratings, and ...
Rosenblum L D - - 1997
In the McGurk effect, perceptual identification of auditory speech syllables is influenced by simultaneous presentation of discrepant visible speech syllables. This effect has been found in subjects of different ages and with various native language backgrounds. But no McGurk tests have been conducted with prelinguistic infants. In the present series ...
White-Traut R C - - 1997
PURPOSE: To examine the immediate responses of preterm infants to two forms of unimodal [auditory only (A) and tactile only (T)] and two forms of multimodal sensory stimulation [auditory, tactile and visual (ATV); auditory, tactile, visual and vestibular (ATVV)]. METHOD: A convenience sample of 54 clinically stable preterm infants (33-34 ...
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