Search results for "Percept"
showing 10 items of 3839 documents
Entropy of balance--some recent results.
2010
Abstract Background Entropy when applied to biological signals is expected to reflect the state of the biological system. However the physiological interpretation of the entropy is not always straightforward. When should high entropy be interpreted as a healthy sign, and when as marker of deteriorating health? We address this question for the particular case of human standing balance and the Center of Pressure data. Methods We have measured and analyzed balance data of 136 participants (young, n = 45; elderly, n = 91) comprising in all 1085 trials, and calculated the Sample Entropy (SampEn) for medio-lateral (M/L) and anterior-posterior (A/P) Center of Pressure (COP) together with the Hurst…
Dosage individualization of erythropoietin using a profile-dependent support vector regression
2003
The external administration of recombinant human erythropoietin is the chosen treatment for those patients with secondary anemia due to chronic renal failure in periodic hemodialysis. The objective of this paper is to carry out an individualized prediction of the EPO dosage to be administered to those patients. The high cost of this medication, its side-effects and the phenomenon of potential resistance which some individuals suffer all justify the need for a model which is capable of optimizing dosage individualization. A group of 110 patients and several patient factors were used to develop the models. The support vector regressor (SVR) is benchmarked with the classical multilayer percept…
Are individuals with an eating disorder less sensitive to aesthetic flaws than healthy controls?
2008
Abstract Objective This study aimed to investigate whether the positive evaluation of other people's bodies is due to difficulties in the recognition of flaws in attractive features of others. Method Thirty female individuals with an eating disorder (IEDs) and 30 normal controls (NCs) rated pictures of a woman's face in relation to various manipulated facial features. Accuracy rates, discrepancy scores, and response times were assessed. Participants also answered questionnaires relating to social comparison, internalization of the slender ideal, and eating disorder symptoms. Results NCs were significantly more accurate at detecting flaws and recognized the degree of manipulation better than…
Influence of appearance-related TV commercials on body image state.
2008
This study investigates the influence of media exposure on body image state in eating-disordered (ED) patients. The attitudinal and perceptual components of body image are assessed, as well as any associations with dysfunctional cognitions and behavioral consequences. Twenty-five ED patients and 25 non-ED controls (ND) viewed commercials either featuring appearance (AC; 5 min) or not featuring appearance (NC; 5 min). Both perceptual and attitudinal body image components changed markedly after the AC condition for ED patients, compared with the ND group and NC condition. Cognitions referring to dietary restraint and internalization/social comparison also changed significantly in ED patients…
Cerebellar patients demonstrate preserved implicit knowledge of association strengths in musical sequences
2006
Recent findings suggest the involvement of the cerebellum in perceptual and cognitive tasks. Our study investigated whether cerebellar patients show musical priming based on implicit knowledge of tonal-harmonic music. Participants performed speeded phoneme identification on sung target chords, which were either related or less-related to prime contexts in terms of the tonal-harmonic system. As groups, both cerebellar patients and age-matched controls showed facilitated processing for related targets, as previously observed for healthy young adults. The outcome suggests that an intact cerebellum is not mandatory for accessing implicit knowledge stored in long-term memory and for its influenc…
Mismatch negativity (MMN) as a tool for investigating auditory discrimination and sensory memory in infants and children
2000
For decades behavioral methods, such as the head-turning or sucking paradigms, have been the primary methods to investigate auditory discrimination, learning and the function of sensory memory in infancy and early childhood. During recent years, however, a new method for investigating these issues in children has emerged. This method makes use of the mismatch negativity (MMN), the brain's automatic change-detection response, which has been used intensively in both basic and clinical studies in adults for twenty years. This review demonstrates that, unlike many other components of event-related potentials, the MMN is developmentally quite stable and can be obtained even from pre-term infants…
Amusic does not mean unmusical: Beat perception and synchronization ability despite pitch deafness
2013
Pitch deafness, the most commonly known form of congenital amusia, refers to a severe deficit in musical pitch processing (i.e., melody discrimination and recognition) that can leave time processing--including rhythm, metre, and "feeling the beat"--preserved. In Experiment 1, we show that by presenting musical excerpts in nonpitched drum timbres, rather than pitched piano tones, amusics show normal metre recognition. Experiment 2 reveals that body movement influences amusics' interpretation of the beat of an ambiguous drum rhythm. Experiment 3 and a subsequent exploratory study show an ability to synchronize movement to the beat of popular dance music and potential for improvement when give…
Motion-Cuing Algorithms
2015
Objective:The aim of this study was to characterize the human response to motion-cuing algorithms (MCAs) by comparing users’ perception to several proposed objective indicators.Background:Other researchers have proposed several MCAs, but few improvements have been achieved lately. One of the reasons for this lack of progress is that fair comparisons between different algorithms are hard to achieve, for their evaluation needs to be performed with humans and the tuning process is slow.Method:This characterization is performed by means of a comparison of the subjective perception of vehicle simulation users (90 participants) against several proposed objective indicators that try to measure MCA…
Legibility of Text and Pictograms in Variable Message Signs: Can Single-Word Messages Outperform Pictograms?
2018
The current research shows the advantage of single-word messages in the particular case of variable message signs (VMSs) with a high aspect ratio.Early studies on traffic sign design proposed that pictorial information would advantage equivalent text messages in static signs.We used a driving simulator to present individually 36 VMSs, showing six words (e.g., "congestion") and six danger signs (e.g., congestion traffic sign). In Experiment 1, 18 drivers read aloud the text or orally identified the pictograms as soon as they could correctly do it. In Experiment 2, a different sample of 18 drivers gave a motor response, according to the meaning of the message. We analyzed the legibility dista…
Thalamic infarctions cause side-specific suppression of vestibular cortex activations.
2005
H2O15-PET was performed during caloric vestibular stimulation of the right and left external ears in eight right-handed patients with acute unilateral infarctions or haemorrhages of the posterolateral thalamus (four right, four left). The posterolateral thalamus is the relay station for ipsi- and contralateral ascending vestibular input to the multiple multisensory vestibular cortex areas. The aim of this study was to evaluate the differential effects of unilateral vestibular thalamic lesions on thalamo-cortical projections, right hemispheric dominance and reciprocal inhibitory visual-vestibular interaction, as well as perceptual and ocular motor consequences during caloric irrigation. The …