Search results for "Eye movement"
showing 10 items of 238 documents
Sleep phenotypes of intellectual disability: a polysomnographic evaluation in subjects with Down syndrome and Fragile X syndrome
2008
Abstract Objective To analyze sleep architecture and NREM sleep alterations by means of the Cyclic Alternating Pattern (CAP) in children with Down syndrome (DS) and Fragile-X syndrome (fraX), the two most common causes of inherited mental retardation, in order to find out eventual alterations of their sleep microstructure related to their mental retardation phenotypes. Methods Fourteen patients affected by fraX (mean age 13.1 years) and 9 affected by Down syndrome (mean age 13.8 years) and 26 age-matched normal controls were included. All subjects underwent overnight polysomnography in the sleep laboratory, after one adaptation night and their sleep architecture and CAP were visually scored…
Differences in Visual Attention Patterns to Sexually Mature and Immature Stimuli Between Heterosexual Sexual Offenders, Nonsexual Offenders, and Nono…
2018
Men, whether gynephilic or androphilic, show both early and late attention toward adults and not toward children. We examined early and late visual attention to sexually mature versus immature stimuli in four groups of heterosexual men: sexual offenders against children (SOAC = 18), sexual offenders against adults (SOAA = 16), nonsexual offenders (NSO = 18), and nonoffending men (NOM = 19). We simultaneously presented adult and child stimuli and measured time to first fixation, number of first fixations, total duration of fixation, and fixation count to four areas of interest: entire body, then face, chest, and pelvis. We found a significant interaction where only SOAC tended to fixate more…
Online detection of rem sleep based on the comprehensive evaluation of short adjacent eeg segments by artificial neural networks
1997
Abstract 1. 1. For scientific and clinical requirements the present objective is a robust automatic online algorithm to detect rapid eye movement (REM) steep from single channel sleep EEG data without using EMG or EOG information. 2. 2. For data preprocessing 20 seconds time periods of the continuous EEG activity are digitally filtered in 7 frequency bands. Then the RMS values of these filtered signals are calculated along segments of 2.5 seconds. The resulting matrix of RMS values is representing information on the power of the signal localized in time and frequency and serves as input to an artificial neural network. A pooled set of EEG data together with the corresponding manual evaluati…
Conventional and spectral power analysis of all-night sleep EEG after subchronic treatment with paroxetine in healthy male volunteers.
1998
Paroxetine is a selective and potent serotonin reuptake inhibitor with reported antidepressant properties. Since changes in the regular sleeping pattern were described as side effects under treatment with paroxetine, the impact of the drug on the sleep architecture is of major interest. The present study addressed the question of subchronic effects of paroxetine medication (30 mg/day) in eight healthy male volunteers in a double blind, placebo-controlled crossover-design. Conventional sleep EEG parameters and additionally computed spectral power analysis based on FFT of 20-s time epochs in the delta, theta, alpha, beta and gamma frequency range for different sleep stages after 4 weeks of tr…
Parafoveal versus foveal N400s dissociate spreading activation from contextual fit.
2009
Using concurrent electroencephalogram and eye movement measures to track natural reading, this study shows that N400 effects reflecting predictability are dissociable from those owing to spreading activation. In comparing predicted sentence endings with related and unrelated unpredicted endings in antonym constructions ('the opposite of black is white/yellow/nice'), fixation-related potentials at the critical word revealed a predictability-based N400 effect (unpredicted vs. predicted words). By contrast, event-related potentials time locked to the last fixation before the critical word showed an N400 only for the nonrelated unpredicted condition (nice). This effect is attributed to a parafo…
Effects of Emotional Context on Memory for Details: The Role of Attention
2013
It was repeatedly demonstrated that a negative emotional context enhances memory for central details while impairing memory for peripheral information. This trade-off effect is assumed to result from attentional processes: a negative context seems to narrow attention to central information at the expense of more peripheral details, thus causing the differential effects in memory. However, this explanation has rarely been tested and previous findings were partly inconclusive. For the present experiment 13 negative and 13 neutral naturalistic, thematically driven picture stories were constructed to test the trade-off effect in an ecologically more valid setting as compared to previous studies…
Did you see that? Dissociating advanced visual information and ball flight constrains perception and action processes during one-handed catching
2013
The integration of separate, yet complimentary, cortical pathways appears to play a role in visual perception and action when intercepting objects. The ventral system is responsible for object recognition and identification, while the dorsal system facilitates continuous regulation of action. This dual-system model implies that empirically manipulating different visual information sources during performance of an interceptive action might lead to the emergence of distinct gaze and movement pattern profiles. To test this idea, we recorded hand kinematics and eye movements of participants as they attempted to catch balls projected from a novel apparatus that synchronised or de-synchronised ac…
Who is looking at me? The cone of gaze widens in social phobia
2011
Gaze direction is an important cue that regulates social interactions and facilitates joint attention. Although humans are very accurate in determining gaze directions in general, they have a surprisingly liberal criterion for the presence of mutual gaze. Using an established psychophysical task that required observers to adjust the eyes of a virtual head to the margins of the area of mutual gaze, we examined whether the resulting cone of gaze is altered in people with social phobia. It turned out that during presence of a second virtual person, the gaze cone's width was specifically enlarged in patients with social phobia as compared to healthy controls. The size of this effect was correla…
Asymmetric modulation of human visual cortex activity during 10 degrees lateral gaze (fMRI study).
2005
We used BOLD fMRI to study the differential effects of the direction of gaze on the visual and the ocular motor systems. Fixation of a target straight ahead was compared to fixation of a target 10 degrees to the right and 10 degrees to the left from gaze straight ahead, and to eyes open in complete darkness in thirteen healthy volunteers. While retinotopic coordinates remained the same in all fixation conditions, the fixation target shifted with respect to a head-centered frame of reference. During lateral fixation, deactivations in higher-order visual areas (one ventral cluster in the lingual and fusiform gyri and one dorsal cluster in the postero-superior cuneus) and, as a trend, activati…
Acquired monocular elevation paresis. An asymmetric upgaze palsy.
1992
Five patients with acquired monocular elevation paresis were investigated using direct current electrooculography. With recovery, upward saccade velocities significantly increased in both eyes in all patients. The gain of upward-following eye movements significantly increased in the paretic eye of all patients and in the opposite eye of four patients. These findings are interpreted in terms of an asymmetric upgaze palsy which clinically presented as monocular elevation paresis in the more severely affected eye. A brainstem lesion contralateral to monocular elevation paresis was suggested in four patients by contralateral Horner's syndrome and contralateral abduction paresis, each in one pat…