Search results for "Sensor"
showing 10 items of 4594 documents
Holistic face processing is induced by shape and texture.
2013
There is increasing evidence that shape and texture are integral parts of face identity. However, it is less clear whether face-specific processing mechanisms are triggered by face shape alone, or if texture might play an important role. We address this question by studying mechanisms involved in holistic face processing. Face stimuli were either full-color pictures of real faces (shape and texture) or line drawings of the same faces (shape without texture). In a change detection task subjects judged whether eyes and eyebrows in two otherwise identical, sequentially presented faces were different in size or not. Afterwards, subjects had to identify the just presented face among two distrac…
Path Following in Non-Visual Conditions.
2018
Path-following tasks have been investigated mostly under visual conditions, that is when subjects are able to see both the path and the tool, or limb, used for navigation. Moreover, only basic path shapes are usually adopted. In the present experiment, participants must rely exclusively on continuous, non-speech, and ecological auditory and vibrotactile cues to follow a path on a flat surface. Two different, asymmetric path shapes were tested. Participants navigated by moving their index finger over a surface sensing position and force. Results show that the different non-visual feedback modes did not affect the task's accuracy, yet they affected its speed, with vibrotactile feedback causin…
Effects of masked repetition priming and orthographic neighborhood in visual recognition of words.
1996
Summay.-The role of orthographic neighborhood (neighborhood size and neighborhood Erequency) in visual-word recognition was analyzed using the masked repetition-priming paradigm. Specifically, we varied stimulus-onset asynchrony (33, 50, and 67 msec.) and type of prime (identical, unrelated, unprimed) in a lexical-decision task. Analyses show additive effects of repetition and stimulus-onset asynchrony. Further, the unrelated condition overestimated the repetition effects relative ro an unprimed condition. Fachtatory effects of neighborhood size and inhibitory effects of neighborhood frequency were also found. The results are interpreted in terms of current models of visual-word recognition…
Role of sensorimotor areas in early detection of motor errors: An EEG and TMS study
2019
Abstract Action execution is prone to errors and, while engaged in interaction, our brain is tuned to detect deviations from what one expects from other’s action. Prior research has shown that Event-Related-Potentials (ERPs) are specifically modulated by the observation of action mistakes interfering with goal achievement. However, in complex and modular actions, embedded motor errors do not necessarily produce an immediate effect on the global goal. Here we dissociate embedded motor goals from global action goals by asking subjects to observe familiar but untrained knotting actions. During knotting an embedded motor error (i.e. the rope is inserted top-down instead of bottom-up during the …
Unconscious response priming during continuous flash suppression.
2017
Continuous flash suppression (CFS) has become a popular tool for studying unconscious processing, but the level at which unconscious processing of visual stimuli occurs under CFS is not clear. Response priming is a robust and well-understood phenomenon, in which the prime stimulus facilitates overt responses to targets if the prime and target are associated with the same response. We used CFS to study unconscious response priming of shape: arrows with left or right orientation served as primes and targets. The prime was presented near the limen of consciousness and each trial was followed by subjective rating of visibility and a forced-choice response concerning the orientation of the prime…
Precision of a commercial hartmann-shack aberrometer: limits of total wavefront laser vision correction.
2012
Purpose To assess the intrasession and intersession precision of higher-order aberrations (HOAs) measured using a commercial Hartmann-Shack wavefront sensor (Zywave; Bausch & Lomb) in refractive surgery candidates. Design Prospective, experimental study of a device. Methods To analyze intrasession repeatability, 1 experienced examiner measured 30 healthy eyes 5 times successively. To study intersession reproducibility, the same clinician obtained measurements from another 30 eyes in 2 consecutive sessions at the same time of day 1 week apart. Results For intrasession repeatability, excellent intraclass correlation coefficients (ICCs) were obtained for total ocular aberrations, total HOAs, a…
The effect of aberrations on objectively assessed image quality and depth of focus
2017
The effects of aberrations on image quality and the objectively assessed depth of focus (DoF) were studied. Aberrometry data from 80 young subjects with a range of refractive errors was used for computing the visual Strehl ratio based on the optical transfer function (VSOTF), and then, through-focus simulations were performed in order to calculate the objective DoF (using two different relative thresholds of 50% and 80%; and two different pupil diameters) and the image quality (the peak VSOTF). Both lower order astigmatism and higher order aberration (HOA) terms up to the fifth radial order were considered. The results revealed that, of the HOAs, the comatic terms (third and fifth order) ex…
Optical factors influencing the amplitude of accommodation
2017
AbstractThe purpose of this work was to find plausible predictors among optical parameters that may explain the inter-individual differences in subjective amplitude of accommodation not explained by age. An exploratory multivariable regression analysis was carried out retrospectively on a dataset with 180 eyes from 97 subjects (ages ranged from 20 to 58years). Subjective amplitudes of accommodation were recorded with the use of a custom-made Badal system. A commercial aberrometer was used to obtain each eye’s wavefront during the full range of accommodation. The plausible predictors under study were pupil diameter in the unaccommodated eye, its reduction with accommodation; fourth- and six-…
The processing of mispredicted and unpredicted sensory inputs interact differently with attention
2018
International audience; Prediction and attention are fundamental brain functions in the service of perception. Interestingly, previous investigations found prediction effects independent of attention in some cases but attention-dependent in other cases. The discrepancy might be related to whether the prediction effect was revealed by comparing mis-predicted event (where there is incorrect prediction) or unpredicted event (where there is no precise prediction) against predicted event, which are associated with different precision-weighted prediction error. Here we conducted a joint analysis on four published electroencephalography (EEG) datasets which allow for proper dissociation of mispred…
Difficult memory task during postural tasks of various difficulties in young and older people: A pilot study
2007
Abstract Objective This study examined the effects of a difficult and individually tailored additional cognitive task on postural stability and electromyographic (EMG) activities of the ankle dorsi- and plantar-flexors, in young and older individuals performing postural tasks of varying difficulties. Methods Eight young (mean age = 24 years) and eight older (74 years) men took part in the investigation. Centre of pressure velocity and surface EMG of ankle joint muscles were both examined during various postural conditions. Results The main findings suggested that high levels of muscle activity were a characteristic of age-related declines in postural stability. Moreover, during the complex …