Search results for "Spatial perception"
showing 10 items of 14 documents
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…
Neglect-like effects induced by tDCS modulation of posterior parietal cortices in healthy subjects
2011
Background Repetitive transcranial magnetic stimulation (rTMS) over right posterior parietal cortex was shown to induce interference on visuospatial perception in healthy subjects. Transcranial direct current stimulation (tDCS) is another noninvasive brain stimulation technique that works modulating cortical activity. It is applied through easy to use, noncostly, and portable devices. Objective/Hypothesis The aim of the current study was to investigate if the novel approach of “dual” stimulation over parietal cortices compared with the unilateral (right) cathodal one is able to induce greater and/or longer-lasting neglect-like effects in normal subjects performing a computerized visuospatia…
Altered tactile localization and spatiotemporal integration in complex regional pain syndrome patients
2018
Background In complex regional pain syndrome (CRPS), altered perception of the affected hand and neglect-like symptoms of the affected body side are common features. In this study, we presented tactile stimuli to the affected hands in CRPS patients and matched healthy controls. Methods The participants' task was to point at the perceived positions of the stimuli using a tracking device. The spatial coordinates of the perceived positions were analysed for accuracy and consistency. We also presented patterns consisting of two stimuli at distinct positions with a delay of 100 ms. These patterns are known to induce spatiotemporal integration ("sensory saltation"). Results CRPS patients were les…
Paired pulse TMS over the right posterior parietal cortex modulates visuospatial perception
2006
Abstract Objective We previously observed a relative contralateral neglect by right parietal single-pulse TMS given 150 ms after visual stimulus presentation. Here we investigated the effects of parietal paired TMS in normal subjects performing a visuospatial task. Methods Thirteen right-handed healthy subjects underwent a line-length judgement task during single-pulse and paired (1, 3, 5, 10 ms ISIs) TMS, delivered on the right parietal cortex 150 ms after visual stimulus. Results Single pulse TMS over the right parietal cortex induced a significant rightward bias compared to the baseline condition. At 1 and 3 ms ISIs, paired-pulse TMS did not show any effect in comparison with single puls…
Comparative assessment of spatial perception in augmented reality depending on the consistency of depth cues
2021
Discrepancies between depth cues (accommodation and vergence) is one of the major issues caused in a stereoscopic augmented reality at close viewing distances. It adversely affects not only user comfort but also spatial judgements. Images with consonant cues at different distances have become available due to the implementation of multifocal architecture in the head-mounted displays, although its effect on spatial perception has remained unknown. In this psychophysical study, we investigated the effects of consonant and conflicting depth cues on perceptual distance matching in the stereoscopic environment of augmented reality using a head-mounted display that was driven in two modes: multif…
The Facilitation of Design Students’ Spatial Perception in Study Process
2015
Spatial thinking is a considerable structural component of design students’ professional competence. Objective of the current study is to evaluate and promote spatial perception of students using in the learning process principles of universal design for learning (UDL). As the result a model for development of design students spatial perception has been developed and approbated.
Tactile field and the dual nature of touch: Poster
2021
I investigate whether it is justified to postulate tactile field analogous in its properties to visual field. I argue that the answer is both ‘yes’ and ‘no’ due to the dual nature of touch: touch is both an interoceptive modality which presents states of one’s body and an exteroceptive modality which presents external entities. More specifically, the interoceptive tactile space, in which tactile bodily sensations are experienced to be localized, has a character of a spatial field. On the other hand, the exteroceptive tactile space, in which external, tactile objects are experienced to be localized does not have field-status.
Cognitive deficits associated with acquired amusia after stroke: A neuropsychological follow-up study
2009
Recent evidence on amusia suggests that our ability to perceive music might be based on the same neural resources that underlie other higher cognitive functions, such as speech perception and spatial processing. We studied the neural correlates of acquired amusia by performing extensive neuropsychological assessments on 53 stroke patients with a left or right hemisphere middle cerebral artery (MCA) stroke 1 week, 3 months, and 6 months after the stroke. In addition, structural magnetic resonance imaging (MRI) was performed on all patients 1 week and 6 months post-stroke. Based on their performance on a shortened version of the Montreal Battery of Evaluation of Amusia (MBEA), the patients we…
Music and speech prosody: a common rhythm
2013
Disorders of music and speech perception, known as amusia and aphasia, have traditionally been regarded as dissociated deficits based on studies of brain damaged patients. This has been taken as evidence that music and speech are perceived by largely separate and independent networks in the brain. However, recent studies of congenital amusia have broadened this view by showing that the deficit is associated with problems in perceiving speech prosody, especially intonation and emotional prosody. In the present study the association between the perception of music and speech prosody was investigated with healthy Finnish adults (n = 61) using an on-line music perception test including the Scal…
Telpisko prasmju novērtēšanas testa digitālās versijas izstrāde
2021
Maģistra darbā izpētīta telpiskās uztveres un kognitīvo procesu teorija, kas ietver procesu komponentes, references ietvarus, telpiskās spējas, telpisko spēju pielietojumu dažādās nozarēs, telpisko spēju atšķirības starp dažādiem indivīdiem un informāciju par telpisko spēju novērtēšanu ar telpisko testu palīdzību. Pēc teorijas izpētes, tika izstrādāts telpisko prasmju novērtēšanas rīks, kas tika izmantots cilvēku testēšanai, lai noteiktu telpiskās spējas kontekstā ar izglītības un profesionālo nozaru virzienu, kur tās var būt noderīgas un pat nepieciešamas. Izmantojot izstrādāto telpisko spēju novērtēšanas rīku, tika ievākti dati un veikta iegūto rezultātu analīze, kā arī izdarīti secinājum…