Search results for "Intelligence"
showing 10 items of 6959 documents
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…
Dimension reduction: additional benefit of an optimal filter for independent component analysis to extract event-related potentials.
2011
The present study addresses benefits of a linear optimal filter (OF) for independent component analysis (ICA) in extracting brain event-related potentials (ERPs). A filter such as the digital filter is usually considered as a denoising tool. Actually, in filtering ERP recordings by an OF, the ERP' topography should not be changed by the filter, and the output should also be able to be modeled by the linear transformation. Moreover, an OF designed for a specific ERP source or component may remove noise, as well as reduce the overlap of sources and even reject some non-targeted sources in the ERP recordings. The OF can thus accomplish both the denoising and dimension reduction (reducing the n…
DaVinci's Mona Lisa entering the next dimension.
2013
For several of Leonardo da Vinci's paintings, such as The Virgin and Child with St Anne or the Mona Lisa, there exist copies produced by his own studio. In case of the Mona Lisa, a quite exceptional, rediscovered studio copy was presented to the public in 2012 by the Prado Museum in Madrid. Not only does it mirror its famous counterpart superficially; it also features the very same corrections to the lower layers, which indicates that da Vinci and the ‘copyist’ must have elaborated their panels simultaneously. On the basis of subjective (thirty-two participants estimated painter-model constellations) as well as objective data (analysis of trajectories between landmarks of both paintings), …
Monocular Versus Binocular Calibrations in Evaluating Fixation Disparity With a Video-Based Eye-Tracker
2015
When measuring fixation disparity (an oculomotor vergence error), the question arises as to whether a monocular or binocular calibration is more precise and physiologically more appropriate. In monocular calibrations, a single eye fixates on a calibration target that is taken as having been projected onto the center of the fovea; the corresponding vergence state represents the heterophoria (the resting vergence position), which has no effect on the calibration procedure. In binocular calibrations, a vergence error may be present and may affect the subsequent measurement of the fixation disparity during binocular recordings. This study includes a test of the precision of both monocular and …
Measuring Perceived Ceiling Height in a Visual Comparison Task
2017
When judging interior space, a dark ceiling is judged to be lower than a light ceiling. The method of metric judgments (e.g., on a centimetre scale) that has typically been used in such tasks may reflect a genuine perceptual effect or it may reflect a cognitively mediated impression. We employed a height-matching method in which perceived ceiling height had to be matched with an adjustable pillar, thus obtaining psychometric functions that allowed for an estimation of the point of subjective equality (PSE) and the difference limen (DL). The height-matching method developed in this paper allows for a direct visual match and does not require metric judgment. It has the added advantage of pro…
Quantifying the Wollaston Illusion
2020
In the early 19th century, William H. Wollaston impressed the Royal Society of London with engravings of portraits. He manipulated facial features, such as the nose, and thereby dramatically changed the perceived gaze direction, although the eye region with iris and eye socket had remained unaltered. This Wollaston illusion has been replicated numerous times but never with the original stimuli. We took the eyes (pupil and iris) from Wollaston’s most prominent engraving and measured their perceived gaze direction in an analog fashion. We then systematically added facial features (eye socket, eyebrows, nose, skull, and hair). These features had the power to divert perceived gaze direction by…
The Auditory Kuleshov Effect: Multisensory Integration in Movie Editing
2016
Almost a hundred years ago, the Russian filmmaker Lev Kuleshov conducted his now famous editing experiment in which different objects were added to a given film scene featuring a neutral face. It is said that the audience interpreted the unchanged facial expression as a function of the added object (e.g., an added soup made the face express hunger). This interaction effect has been dubbed “Kuleshov effect.” In the current study, we explored the role of sound in the evaluation of facial expressions in films. Thirty participants watched different clips of faces that were intercut with neutral scenes, featuring either happy music, sad music, or no music at all. This was crossed with the facia…
Allocentric time-to-contact and the devastating effect of perspective
2014
AbstractWith regard to impending object–object collisions, observers may use different sources of information to judge time to contact (tC). We introduced changes of the observer’s vantage point to test among three sets of hypotheses: (1) Observers may use a distance-divided-by-velocity algorithm or, alternatively, elaborated τ-formulae, all of which give exact tC information; (2) observers may use simple τ-formulae (i.e., formulae of the type: visual angle divided by its own first temporal derivative); (3) observers may capitalize on non-τ variables. Hypotheses (2) and (3) imply specific patterns of errors. We presented animated, impending collisions between a moving object and a stationar…
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…
Neural Correlates of Visual versus Abstract Letter Processing in Roman and Arabic Scripts
2013
In alphabetic orthographies, letter identification is a critical process during the recognition of visually presented words. In the present experiment, we examined whether and when visual form influences letter processing in two very distinct alphabets (Roman and Arabic). Disentangling visual versus abstract letter representations was possible because letters in the Roman alphabet may look visually similar/dissimilar in lowercase and uppercase forms (e.g., c-C vs. r-R) and letters in the Arabic alphabet may look visually similar/dissimilar, depending on their position within a word (e.g., [Formula: see text] - [Formula: see text] vs. [Formula: see text] - [Formula: see text]). We employed a…