Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 70 for “"Visual stimulus"”.
-
Towards improved visual stimulus discrimination in an SSVEP BCI
The dissertation investigated the influence of stimulus characteristics, electroencephalographic (EEG) electrode location and three signal processing methods on the spectral signal to noise ratio (SNR) of Steady State Visual Evoked Potentials (SSVEPs) with a view for use in Brain-Computer …
-
The effect of a visual stimulus on behavioral state and visual responsiveness in preterm infants
… by preterm infants. In addition, the effects of visual stimulation on the organization of behavioral state and on the development of the visual skills in preterm infants was assessed. Twenty preterm infants were observed at the time of admission and discharge from the intermediate unit of a …
-
Understanding experience-dependent plasticity of cellular and network activity in the mouse primary visual cortex
… impactful sensory modules is vision. Primary visual cortex (V1) in mammals is particularly malleable during a juvenile critical period, but this plasticity lasts even in adulthood. A representative form of visual cortical plasticity is ocular dominance (OD) plasticity following temporary …
-
The Dark Focus of Visual Accommodation: Its Existence, Its Effects, Its Measurement
The "dark focus" or "resting state" of visual accommodation to the refractive state to which the eye tends to return in the absence of any visual stimulus, as in complete darkness. This tendency is reviewed in terms of past and current attempts at its quantification and its effects on visual …
-
Investigation into Stand-alone Brain-computer Interfaces for Musical Applications
… It adopts a paradigm called steady state visually evoked potential (SSVEP) to provide the user with control. It aims to encapsulate all braincomputer music interface (BCMI)-based operations into a stand-alone application, which would improve the portability of BCMIs. This projects …
-
A disjunctive analysis of neonatal approach stimulus prepotence
… the relative importance of auditory and visual stimuli in eliciting initial approach and following responses in domestic fowl. 72 Canadian Athens random-bred chicks were tested at 24 or 36 hours post-hatch. A repetitive, tapping tone (4 per sec., 50 msec. duration, 500 Hz) served as the …
-
Towards an integrated model of feedforward-feedback processing in the visual cortex
… work is to explore a potential improvement on a visual recognition system. The system is a biologically-plausible computational model of the feedforward part of the ventral stream in the visual cortex and successfully models human performance on visual recognition tasks for the first 50-100 …
-
Effetti dell'integrazione visuo-acustica in pazienti con disturbo di campo visivo
Human brain is provided with a flexible audio-visual system, which interprets and guides responses to external events according to spatial alignment, temporal synchronization and effectiveness of unimodal signals. The aim of the present thesis was to explore the possibility that such a system might …
-
The role of context in infant preference for father's voice
… male and female four-month-olds were tested in a visual-fixation preference procedure. Attentional preference was measured by the amount of time the infants watched a visual stimulus. It was found that infants did not show greater attentional or affective responsiveness to paternal ID over …
-
Mild Traumatic Brain Injuries and Their Implications on Changes in Event Related Potentials: A look into Visual Gating (P50)
… a self-reported concussion. Here we show that a visual attention and gating mechanism exists in both populations (control and concussed) as seen by the P50 ERP after the presentation of our visual stimulus, which is dependent on the Order the stimulus is presented (1<sup>st</sup> or …
-
The performance and strategies of adolescents in learning to read artificial words /
… revealed that subjects 1 earned parts of the visual a'nd auditory features of words prior to hooking up the visual stimulus to the word's name. Performance measures-which appear to affect the rate of learning were as follows: auditory short-term memory, auditory delayed short-term memory, …
-
AGING-RELATED DECREMENTS DURING THE ACTIVITIES OF THE TIMED UP AND GO TEST WHEN COMBINED WITH MOTOR TASK AND VISUAL STIMULATION
… is associated with increased reliance on the visual system for postural control, termed “visual dependence”. Discordance between visual, vestibular and proprioceptive sensory information can lead to balance loss and falls. In addition to increased visual dependence (VD), older adults have more …
-
Development, Evaluation, and Analysis of Complex Eye Movement Biometrics
… occur naturally during directed viewing of a visual stimulus. The proposed techniques are then evaluated according to standard practices in the biometric field to assess performance under varying environmental conditions. The results of this evaluation are analyzed to provide recommendations …
-
Observation of training room stimuli in determining stimulus control and transfer of training
… children participated in an assessment of stimulus control and transfer of training. Each subject was taught to perform a simple, nonverbal, imitative task in a training room, and transfer to a novel setting was assessed. During training, subjects were video-taped in order to determine how …
-
The Neural Correlates of Spatial Language
… relationship) and responded to whether or not a visual stimulus matched the preceding auditory sentence. fMRI results revealed that a specific region in bilateral parietal cortex, the precuneus, was significantly active during spatial language processing. In a second experiment, there was a …
-
Mobilização rápida de citocromo-oxidase por estimulação sensorial em córtex visual de gatos e primatas
… (Felis catus) and three monkeys (Cebus apella). Visual stimulus of low spatial frequency, with variations in colour and brightness and no spatial orientation allowed the observation of cytochrome oxidase-rich patches in flattened sections of cat's visual cortex. The patches appeared in Vl, V2 and …
-
Optogenetic disruption of memory-drive, oculomotor behavior in the non-human primate
… three epochs of the memory-guided saccade task: visual stimulus presentation, the delay interval, and motor preparation. It is unclear, though, whether FEF activity during each epoch is necessary for memory-guided saccade execution. To address this question, techniques for millisecond-precise …
-
Oxygen Polarography in the Awake Macaque: Bridging BOLD fMRI and Electrophysiology
… potential and oxygen responses to an engaging visual stimulus in two distinct brain systems. In area V3, a key region in the visual system and representative of stimulus driven sensory cortex, we show increased tissue oxygen and local field potential power in response to visual stimulus. In …
-
State-Space Models and Latent Processes in the Statistical Analysis of Neural Data
… are able to capture the encoding and decoding of visual stimulus to neural code. Our formalism gives us insight into the underlying architecture of the neural system. And we are able to estimate the common-noise that the cells receive. In the third chapter we discuss methods for optimally …
-
Aplicação da entropia de permutação A sinais EEG durante estimulação dinâmica de cenário virtual
… study, such changes were caused by a dynamic visual stimulus (ED). One form of EEG signal analysis is the calculation of signal entropy, which measures the degree of complexity about a particular message or signal. This study consisted in the use of Permutation Entropy (PE) for the analysis of …
Page 1 of 4