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Results 201 - 250 of 952
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Balkenius Anna - - 2010
Here, we analyse the flight behaviour of the hawkmoth Manduca sexta while it approaches three different artificial flower stimuli: a clearly visible blue flower, an invisible scented flower and a flower that is both visible and scented. By tracking the moths in fine temporal detail, we find that flight towards ...
Win-Hall Dorothy M - - 2010
This study was undertaken to compare static and dynamic accommodation measurements using the Grand Seiko WR-5500 (WAM) in young, phakic subjects. Fifteen subjects, aged 20 to 28 years (23.8 ± 0.58 years; mean ± SD years) participated. Accommodation was stimulated with printed text presented at various distances. In static mode, ...
Sabeti Faran - - 2011
Multifocal pupillographic objective perimetry (mfPOP) has the advantage of being a non-invasive, objective method for measuring up to 88 visual field responses from both eyes concurrently within 5min. To date mfPOP has been used to assess the peripheral visual field. Here we examine the practicality of mfPOP for testing the ...
Olsson Shannon B - - 2011
Olfactory studies have expanded beyond the study of single compound odor perception to explore the processing of complex mixtures and blends. The spatiotemporal presentation of blend stimuli is a challenging task requiring volatiles with diverse chemical and physical properties to be presented as a unified stimulus. This not only necessitates ...
Ma Qingguo - - 2010
The aim of the present study is to find the neural features of the impact of induced negative emotion on brand extension. Facing three sequential stimuli in triples consisted of negative emotion pictures (stimulus 1), beverage brand names (stimulus 2), and product names (stimulus 3) in other categories, 20 participants ...
Hoffmann Errol R - - 2010
An experiment is reported that is an extension of Payne (1995) and of Vu and Proctor (2003). These authors used various light/key arrangements to determine the ability of naive subjects to rate the usability of interface designs and found that naive judgements were not accurate, apart from selecting a best ...
Peterchev Angel V AV Division of Brain Stimulation and Therapeutic Modulation, Department of Psychiatry, Columbia University/New York State Psychiatric Institute, New York, NY, USA. - - 2010
In this article, we review the parameters that define the electroconvulsive therapy (ECT) electrical stimulus and discuss their biophysical roles. We also present the summary metrics of charge and energy that are conventionally used to describe the dose of ECT and the rules commonly deployed to individualize the dose for ...
Viswanathan Deepa - - 2010
Having foreknowledge of the type and timing of sensory stimulation modulates the electrophysiological response and can result in short-term habituation. Here we explore if dishabituation is similarly affected. Seventeen healthy subjects were tested with five different auditory stimuli paradigms to see if knowledge of the stimulus train length and/or deviant ...
Yang Qiang Q Montana State University, Bozeman, MT 59717, USA. - - 2010
We demonstrate an integrated FPGA solution to project highly stabilized, aberration-corrected stimuli directly onto the retina by means of real-time retinal image motion signals in combination with high speed modulation of a scanning laser. By reducing the latency between target location prediction and stimulus delivery, the stimulus location accuracy, in ...
Lundström Johan N JN Monell Chemical Senses Center, Philadelphia, PA, United - - 2010
Many human olfactory experiments call for fast and stable stimulus-rise times as well as exact and stable stimulus-onset times. Due to these temporal demands, an olfactometer is often needed. However, an olfactometer is a piece of equipment that either comes with a high price tag or requires a high degree ...
Holmeslet Berit - - 2011
To explore the mechanisms for skull tap induced ocular vestibular evoked myogenic potentials (oVEMP). An electro-mechanical "skull tapper" was used to test oVEMP in response to four different stimulus sites (forehead, occiput and above each ear) in healthy subjects (n=20) and in patients with unilateral loss of vestibular function (n=10). ...
Aquino Gerardo - - 2010
Nonergodic renewal processes have recently been shown by several authors to be insensitive to periodic perturbations, thereby apparently sanctioning the death of linear response, a building block of nonequilibrium statistical physics. We show that it is possible to go beyond the "death of linear response" and establish a permanent correlation ...
Frankó Edit E KU Leuven Medical School, Leuven, - - 2010
It has been proposed that perceptual learning may occur through a reinforcement process, in which consistently pairing stimuli with reward is sufficient for learning. We tested whether stimulus-reward pairing is sufficient to increase the sensorial representation of a stimulus by recording local field potentials (LFPs) in macaque extrastriate area V4 ...
Wang A L - - 2010
Brief radiant laser pulses selectively activate skin nociceptors and elicit transient brain responses (laser-evoked potentials [LEPs]). When LEPs are elicited by pairs of stimuli (S1-S2) delivered at different interstimulus intervals (ISIs), the S2-LEP is strongly reduced at short ISIs (250 ms) and progressively recovers at longer ISIs (2,000 ms). This ...
Elze Tobias - - 2010
In experimental visual neuroscience brief presentations of visual stimuli are often required. Accurate knowledge of the durations of visual stimuli and their signal shapes is important in psychophysical experiments with humans and in neuronal recordings with animals. In this study we measure and analyze the changes in luminance of visual ...
Situ Ping - - 2010
To investigate the interaction between corneal stimuli at different positions and tear secretion and to establish relationships between nociceptive stimuli detection thresholds and stimulated tearing. Using a computerized Belmonte-esthesiometer, mechanical and chemical stimuli, from 0% to 200% of the threshold in 50% steps, were delivered (in random order) to the ...
Kornblum Sylvan - - 2010
Reports an error in "The effects of irrelevant stimuli: 1. The time course of stimulus-stimulus and stimulus-response consistency effects with Stroop-like stimuli, Simon-like tasks, and their factorial combinations" by Sylvan Kornblum, Gregory T. Stevens, Anthony Whipple and Jean Requin (Journal of Experimental Psychology: Human Perception and Performance, 1999[Jun], Vol 25[3], ...
Gulgin Heather - - 2010
Many sports involve movements during which the lower extremity functions as a closed kinetic chain, requiring weight-bearing (WB) range of motion (ROM). Assessment of the capacity for internal and external rotation motion at the hip is typically performed with the individual in a prone, supine, or seated position. Such measurements ...
Krusche Paul - - 2010
We investigated discrimination of large quantities in salamanders of the genus Plethodon. Animals were challenged with two different quantities (8 vs 12 or 8 vs 16) in a two-alternative choice task. Stimuli were live crickets, videos of live crickets or images animated by a computer program. Salamanders reliably chose the ...
Crozier G K D - - 2010
The concept of "market stimulus"--the idea that free markets can play a role in widening access to new technologies--may help support the view that parents should be permitted to purchase germ-line enhancements. However, a critical examination of the topic shows that market stimulus, even if it applies to human genomic ...
Carlsen Anthony N - - 2011
Recent studies have used a loud (>120dB) startle-eliciting acoustic stimulus as a probe to investigate early motor response preparation in humans. The use of a startle in these studies has provided insight into not only the neurophysiological substrates underlying motor preparation, but also into the behavioural response strategies associated with ...
Burnovicz Ana - - 2010
Reports on experience-dependent changes in invertebrate autonomic function are few. In the crab Chasmagnathus, repeated presentations of a visual danger stimulus (VDS) elicit long-term cardiac adjustments. Although these changes can be explained in terms of an associative process, they do not necessarily indicate an anticipatory conditioned response. In the present ...
Favelle Simone - - 2010
The present study investigated the time course of visual information processing that is responsible for successful object change detection involving the configuration and shape of 3-D novel object parts. Using a one-shot change detection task, we manipulated stimulus and interstimulus mask durations (40-500 msec). Experiments 1A and 1B showed no ...
Chan Alan H S - - 2010
This study investigated the performance of 24 participants in eight different three-dimensional spatial stimulus-response (S-R) mapping conditions. The stimulus visual signals were positioned at the corners of an imaginary cube, and responses were made by hands and feet. There was a significant interaction of visual signal position and response device ...
Yue Xiaomin X Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA. - - 2011
An intriguing region of human visual cortex (the fusiform face area; FFA) responds selectively to faces as a general higher-order stimulus category. However, the potential role of lower-order stimulus properties in FFA remains incompletely understood. To clarify those lower-level influences, we measured FFA responses to independent variation in 4 lower-level ...
Kim Tae T Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15203, USA. - - 2010
Inhalation anesthetics (e.g. isoflurane) are preferable for longitudinal fMRI experiments in the same animals. We previously implemented isoflurane anesthesia for rodent forepaw stimulation studies, and optimized the stimulus parameters with short stimuli (1-3-s long stimulation with ten electric pulses). These parameters, however, may not be applicable for long periods of ...
Krieglmeyer Regina - - 2010
Theories from diverse areas of psychology assume that affective stimuli facilitate approach and avoidance behavior because they elicit motivational orientations that prepare the organism for appropriate responses. Recent evidence casts serious doubt on this assumption. Instead of motivational orientations, evaluative-coding mechanisms may be responsible for the effect of stimulus valence ...
Lancioni Giulio E - - 2010
This study assessed whether a program based on microswitch and computer technology would enable three post-coma participants (adults) with motor and communication/consciousness impairments to choose among environmental stimuli and request their repetition whenever they so desired. Within each session, 16 stimuli (12 preferred and 4 non-preferred) were scheduled for the ...
Gerdjikov Todor V - - 2010
Understanding the neural code underlying perception requires the mapping of physical stimulus parameters to both psychophysical decisions and neuronal responses. Here, we employed a novel psychophysical task in head-fixed rats to measure discriminability of vibrotactile whisker deflections. Rats could discriminate 90 Hz from 60 Hz pulsatile stimuli if stimulus intensity ...
Zhang Yan - - 2010
The ongoing neural activity in human primary somatosensory cortex (SI) is characterized by field potential oscillations in the 7-13 Hz range known as the mu rhythm. Recent work has shown that the magnitude of the mu oscillation immediately preceding the onset of a weak stimulus has a significant impact on ...
Logigian Eric L EL Department of Neurology, University of Rochester Medical Center, Box 673, 601 Elmwood Avenue, Rochester, New York, USA. - - 2010
It is unknown how evoked myotonia varies with stimulus frequency or train length, or how it compares to voluntary myotonia in myotonic dystrophy type 1 (DM1). First dorsal interosseous (FDI) tetanic contractions evoked by trains of 10-20 ulnar nerve stimuli at 10-50 HZ were recorded in 10 DM1 patients and ...
Fischmeister Florian Ph S - - 2010
Throughout recent years there has been an increasing interest in studying unconscious visual processes. Such conditions of unawareness are typically achieved by either a sufficient reduction of the stimulus presentation time or visual masking. However, there are growing concerns about the reliability of the presentation devices used. As all these ...
Vergeer Mark - - 2010
In the past decade, effects of pattern coherence have indicated that perception during binocular rivalry does not result solely from reciprocal inhibitory competition between monocular channels. In this study we were interested in feature selectivity both during dominance and during suppression. The first experiment shows that a suppressed stimulus perceptually ...
Zevin Jason D JD Sackler Institute for Developmental Psychobiology, Weill Cornell Medical College, New York, New York 10065, USA. - - 2010
Functional magnetic resonance imaging (fMRI) studies of speech sound categorization often compare conditions in which a stimulus is presented repeatedly to conditions in which multiple stimuli are presented. This approach has established that a set of superior temporal and inferior parietal regions respond more strongly to conditions containing stimulus change. ...
Chen-Bee Cynthia H CH Department of Neurobiology and Behavior, 2205 McGaugh Hall, University of California, Irvine, CA 92697-4550, United States. - - 2010
Intrinsic signal optical imaging (ISOI) can be used to map cortical function and organization. Because its detected signal lasts 10+s consisting of three phases, trials are typically collected using a long (tens of seconds) stimulus delivery interval (SDI) at the expense of efficiency, even when interested in mapping only the ...
Wolfe Benjamin - - 2010
While two-dimensional stimuli may be easily presented with any computer, an apparatus which allows a range of stimuli to be presented in three dimensions is not easily or cheaply available to researchers or clinicians. To fill this gap, we have developed the Realspace Testing System (RTS) which addresses the need ...
Hong S Lee - - 2010
Uncertainty and predictability have remained at the center of the study of human attention. Yet, studies have only examined whether response times (RT) or fixations were longer or shorter under levels of stimulus uncertainty. To date, no study has examined patterns of stimuli and responses through a unifying framework of ...
Chalk Matthew - - 2010
Expectations broadly influence our experience of the world. However, the process by which they are acquired and then shape our sensory experiences is not well understood. Here, we examined whether expectations of simple stimulus features can be developed implicitly through a fast statistical learning procedure. We found that participants quickly ...
Bhatkar Viprali V - - 2010
A fundamental unsolved problem in psychophysical detection experiments is in discriminating guesses from the correct responses. This paper proposes a coherent solution to this problem by presenting a novel classification method that compares biomechanical and psychological responses. Subjects (13) stood on a platform that was translated anteriorly 16 mm to ...
Vasserman Genadiy - - 2010
Traditionally, the information content of the neural response is quantified using statistics of the responses relative to stimulus onset time with the assumption that the brain uses onset time to infer stimulus identity. However, stimulus onset time must also be estimated by the brain, making the utility of such an ...
Khuu Sieu K - - 2010
We examined whether motion blur accompanying apparent motion (AM) affects the shape of a stimulus presented in the motion path. In a two-alternative forced-choice procedure, observers judged the shape of a Gaussian test stimulus flashed in the path of motion, relative to a reference stimulus, which was a circular Gaussian ...
Gazziro Mario M Wernher von Braun Center for Advanced Research, Campinas, SP, BRAZIL. - - 2010
This article describes the development of a dual-monitor visual stimulus generator that is used in neuroscience experiments with invertebrates such as flies. The experiment consists in the visualization of two fixed images that are displaced horizontally according to the stimulus data. The system was developed using off-the-shelf FPGA kits and ...
Wasserman Edward A - - 2010
Discriminating same from different collections of items is central to human thought and reasoning. Recent comparative research suggests that same-different discrimination behavior is not uniquely human, does not require human language, is based on the variability of the collection of items, obeys fundamental psychophysical laws, and may be captured by ...
Elze Tobias - - 2010
In visual psychophysics, precise display timing, particularly for brief stimulus presentations, is often required. The aim of this study was to systematically review the commonly applied methods for the computation of stimulus durations in psychophysical experiments and to contrast them with the true luminance signals of stimuli on computer displays. ...
Johnson Aaron - - 2010
Studies of eccentricity-dependent sensitivity loss typically require participants to maintain fixation while making judgments about stimuli presented at a range of sizes and eccentricities. However, training participants to fixate can prove difficult, and as stimulus size increases, they become poorly localized and may even encroach on the fovea. In the ...
Bruckmann Anna - - 2010
PURPOSE: To compare the results of advanced visual field defects (VFD) measured with the conventional reference perimeter Octopus 101 (O-101) and the new portable T?bingen Mobile Campimeter (TMC). METHODS: Thirty-seven subjects (18 to 75 years), 13 with advanced arcuate scotomas, 12 with VFD respecting vertical meridians, 6 with concentric constriction ...
Serrano-Pedraza Ignacio - - 2010
The perceived direction of motion of a brief visual stimulus that contains fine features reverses if static coarser features are added to it. Here we show that the reversal in perceived direction disappears if the stimulus is reduced in size from 2.8 deg to 0.35 deg radius. We show that ...
Wang Jingyun J Retina Foundation of the Southwest, Dallas, Texas 75231, USA. - - 2010
The goal of this study was to compare objectively the sensitivity of the accommodation system in human infants and adults under binocular and monocular viewing conditions. Full-term infants from 2 to 4 months of age and pre-presbyopic adults were presented with a high-contrast cartoon stimulus moving sinusoidally in diopters around ...
Nahum Louis - - 2011
Adaptive behavior requires the ability to react to potentially harmful stimuli, characterized by high negative inherent emotional salience (iES) (e.g., spiders, snakes), and to the unexpected non-occurrence of anticipated events. When presented simultaneously, threatening stimuli and unexpected absence of anticipated outcomes induce distinct electrocortical responses in different time periods. In ...
Fleming Stephen M SM Wellcome Trust Centre for Neuroimaging, University College London, 12 Queen Square, London, United Kingdom. - - 2010
Wagering contingent on a previous decision, or post-decision wagering, has recently been proposed to measure conscious awareness. Whilst intuitively appealing, it remains unclear whether economic context interacts with subjective confidence and how such interactions might impact on the measurement of awareness. Here we propose a signal detection model which predicts ...
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