bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of prognostic factors on recovery from sudden hearing loss
Authors: Ceylan A , Çelenk F , Kemaloğlu Y K , Bayazıt Y A , Göksu N , Özbi˙len S 
Published: January 2007

AbstractObjective:To define the impact of patient-related and audiovestibular parameters on the prognosis of sudden hearing loss.Methods:Eighty-three patients were included in this retrospective study. All were treated medically. We recorded the patients' demographic parameters, systemic diseases, time elapsed between onset of sudden hearing loss and initiation of treatment, tinnitus, vestibular symptoms, type of initial audiogram, pure tone averages and speech discrimination scores. For all patients, audiological measurements were performed on initial admission and at the completion of treatment on the 10th day.Results:There was no correlation between the hearing gain and recovery rate scores and patients' gender or age (p>0.05). However, a correlation was found between gender and relative hearing gain. Vertigo was not correlated with hearing gain and recovery rate scores (p<0.05). However, relative hearing gain correlated negatively with the presence of vertigo (−r=0.05, 81 degrees of freedom,p=0.043). Patients with <40 dB hearing loss on admission showed a better relative hearing gain (r=0.55, 81 degrees of freedom,p=0.03). Relative hearing gain correlated positively with better pre-treatment speech discrimination scores (r=0.82, 81 degrees of freedom,p=0.009) and negatively with poorer pre-treatment pure tone averages (−r=0.082, 81 degrees of freedom,p=0.009). There was no correlation between the scores for hearing gain, relative hearing gain and recovery rate and: systemic diseases (p>0.05); time elapsed between onset of sudden hearing loss and initiation of treatment (p>0.05); type of audiogram on initial admission (p>0.05), except for midfrequency type of audiogram; and tinnitus (p>0.05).Conclusions:The outcome of sudden hearing loss was unaffected by systemic disease, tinnitus or type of audiogram (except for midfrequency type). The following were poor prognostic factors in the outcome of sudden hearing loss: female gender, presence of vertigo, initiation of treatment more than seven days after onset of hearing loss, and >40 dB hearing loss on admission.
Search Time as a Function of Context Letter Frequency
Authors: Latimer C R 
Published: January 2007

Neisser (1967) posits the operation of purely feature analytic processes in the scanning of context letters in search lists. This contention was tested by varying the relative frequency of occurrence in English of the context letters in alphanumeric search lists, while holding their feature content constant. It was hypothesized that faster search time on lists of high-frequency context letters would indicate letter-level processing. Equality of search time would indicate the purely feature-level processing required by Neisser's theory. Context letters were segregated into high- and low-frequency sets and their features defined and held constant according to two feature analyses. This yielded a 2 × 2 design with 22 subjects per condition. Attention was given to the control of feature frequency, size of the context-letter set, and approximation of English at the level of bigram, trigram, and word. Results supported a letter level or template model of processing but were shown also to be explainable in terms of some feature-testing models of pattern recognition. Apparatus which allowed for the removal of reaction time in search lists is described.
Luminance Thresholds for Motion Contingent on Colour
Authors: Mayhew J E W 
Published: January 2007

Sekuler and Ganz (1963) called the difference in luminance threshold for movement in the same direction versus movement in the opposite direction to the adapting motion ‘direction-specific adaptation’ (DSA). The experiments reported here investigate colour-contingent DSA. After exposure of subjects to clockwise motion of a red pattern alternating with counterclockwise motion of a green pattern, their threshold for clockwise motion was found to be greater than for counterclockwise motion when the illumination was red, but lower when the illumination was green.
Relation between the Magnitude of Flicker Sensation and Evoked Potential Amplitude in Man
Authors: Regan D , Beverley K I 
Published: January 2007

Estimates of the subjective magnitudes of flicker sensations correlate poorly with the amplitudes of electrical brain responses (evoked potentials). A power function of exponent between 0·9 and 1·5 describes the relation between stimulus and subjective sensory magnitude. On the other hand, the relation between stimulus and objective measure varies with electrode position, is different for different frequency components of the evoked potential, and may not be a power function at all. As a rough generalisation, correlations between evoked potentials and perception are poorer when spatially-unpatterned stimuli are used than when the stimulus is spatially patterned.
Some Effects of Exposure to Optical Disarrangement on Adaptation to Optical Rearrangement
Authors: Uhlarik J 
Published: January 2007

Although optical rearrangement has been extensively investigated, disarrangement has received far less attention. It is quite possible that the response of the perceptual system to the latter state, which entails a decorrelation of the normal relationship between vision and motor behavior, will lead to a better understanding of the nature of visual spatial localization. Two studies are described in which exposure (and adaptation) to prism-displaced vision is preceded by a period of exposure to disarrangement. In the first study, concurrent exposure with a target was used. No increase in localization variability resulted from preexposure to disarrangement. However, it was found that this experience retarded the subsequent adaptation to rearrangement, relative to a condition of preexposure to normal viewing. It is argued that this result supports the existence of a cross-correlator comparator mechanism in sensorimotor coordination. The second study was similar to the first except that there was no target-error information available during disarrangement or rearrangement. The pattern of results for the second study was different from those of the first study; this suggests that there might be important differences in the manner in which information regarding intermodality discordance and target-error is processed by the comparator.
Motor-Transformation Learning
Authors: Hay J C 
Published: January 2007

Motor-transformation learning theory asserts that people learn through experience what stimulus transformations are under the control of their behavior. More specifically, it asserts that the parameter values of certain predetermined transformation groups are learned. This theory was inferred, in the first place, from research on adaptation to optical rearrangement—in particular, from position-constancy adaptation in inverting-spectacles experiments, prism-displacement experiments, and in more recent computer-controlled feedback experiments. The detailed characteristics of position-constancy adaptation are found to be consistent with the theory. Diverse consequences radiate from the theory for other human abilities, both in perception and in memory retrieval. These diverse implications are tested in studies of (a) learning to manipulate ‘objects’ in an artificial computer-controlled visual space; (b) learning to compute, in the absence of overt action, the consequences of such action; (c) learning how to access the features of prior stimuli by the execution of motor actions.
The Effect of Stationary Patterns on Adaptation for Movement: Evidence for Inhibitory Interaction
Authors: Mayhew John E W 
Published: January 2007

Contingent movement aftereffects (CMAEs) can be demonstrated by adapting to a red pattern rotating clockwise (cw) alternating with a green pattern rotating counterclockwise (ccw). After 5 min subjects typically report stationary test patterns as apparently rotating clockwise when they are green and counterclockwise when they are red. Also, luminance thresholds for motion now depend on both the colour and direction of the moving pattern. The thresholds for red—cw and green—ccw motion will be relatively greater than for the opposite colour motion pairings. This is called contingent threshold elevation. When stationary dots the same colour as the moving patterns are added to the adapting stimuli, subjects report weak CMAEs but no contingent threshold elevation can be demonstrated. When stationary dots opposite in colour to the moving patterns are added to the adapting stimuli, neither CMAEs nor contingent threshold elevation can be demonstrated. And yet colour specific adaptation does occur, and can be demonstrated in the colour specificity of the simple movement aftereffect. When stationary dots are added to the adapting pattern, the simple movement aftereffect though reduced, is greatest on a test pattern of the same colour as the moving dots. These findings suggest that the CMAE, contingent threshold elevation, and the colour specificity of the movement aftereffect involves neural processes differentially sensitive to the presence of stationary patterns.
Implicit Labelling and Readiness for Pronunciation during the Perceptual Process
Authors: Noizet Georges , Pynte Joël 
Published: January 2007

The authors assume that during the visual perception of labelable objects there occurs an implicit labelling which gives rise to a readiness for pronunciation, and that the two phenomena are involved in stimulus processing. In order to test these assumptions, the duration of eye fixation on drawings representing familiar objects was measured. The data show that on an average this duration was longer when the name for the object required four or five syllables to pronounce than when it required only one syllable. This syllable effect was observed in various experimental conditions where possible effects of other variables could be controlled. The effect was obtained irrespective of whether or not the subjects were allowed to see the drawings before the experiment, and of whether or not they were allowed to go through the list of names for the objects.
Individual Variation in Directional Bias in Visual Perception
Authors: Annett Marian 
Published: January 2007

Directional biases in visual perception were examined for individual differences in sixty-five subjects on two tasks. One task required judgments of the onset asynchrony of pairs of dots presented at random, either one dot in each visual field, or both in the left visual field (LVF), or the right visual field (RVF). The second task required the recall of four letter strings presented randomly in either visual field. Dot-asynchrony judgments were influenced by two main biases: first, an outward from the centre bias in both visual fields, and second, a lateral bias which was significantly from left to right (L—R) in the total sample. A substantial minority of subjects were biased to judge the dots as occurring in right to left (R—L) order. Accuracy of letter report decreased fairly consistently from L—R in the RVF but varied in the LVF. Some subjects showed a L—R report gradient, some a R—L gradient, and some a U-shaped recall pattern. Significant correlations between measures of L—R and R—L biases on the two tasks show that the biases have some stable foundation. The findings suggest that there are directional biases affecting visual perception which are due neither to learned reading habits, nor to cerebral specialization of function.
Rivalry with Continuous and Flashed Stimuli as a Measure of Ocular Dominance across the Visual Field
Authors: Leat Susan J , Woodhouse J Margaret 
Published: January 2007

Two measures of sensory ocular dominance were compared. Both involved dichoptic presentation of orthogonal gratings—a situation which results in binocular rivalry. The gratings were presented briefly in experiment 1 and continuously in experiment 2 and by the predominance of one grating over the other a quantitative estimation of ocular dominance was obtained in both cases. Comparison of the results showed that (a) binocular rivalry suppression was present for exposures of 250 ms and (b) the briefly presented gratings were a more sensitive test for ocular dominance than conventional continuously presented stimuli. The variation of dominance over the horizontal meridian of the visual field was considered. For many subjects a consistent different in the ocular dominance in the two halves of the visual field, and therefore of the cortex, was found. Some showed dominance of the ipsilateral eye in each hemisphere while others showed dominance of the contralateral eye. It was found that there is, in fact, a continuum of types of dominance pattern amongst individuals.
Pattern and Orientation Effects on Afterimage Duration
Authors: Cerf-Beare Aleeza 
Published: January 2007

Patterns composed of a pair of lines: vertical+horizontal, vertical+oblique, horizontal+oblique, and oblique+oblique, either centrally-aligned or edge-aligned, were shown at two positions of rotation. After a 1-s exposure to the pattern observers timed the duration of afterimages consisting of individual lines (fragmentary state) and the pattern as a whole (unitary state) for the ensuing 60 s. Summing unitary and fragmentary afterimage durations yielded the total afterimage duration for each pattern. Three hypotheses were confirmed by the results: (i) total afterimage duration is constant for all patterns when integrated spatiotemporal luminances are equal; (ii) unitary afterimage duration is also constant; (iii) fragmentary afterimages of vertically oriented lines have longer durations than either their horizontal or oblique pair members, regardless of alignment and, with one exception, rotation. For all patterns, the durations of the unitary and the fragmentary state represent a fixed portion of the total afterimage duration. The difference between afterimage duration for differently oriented lines in patterns which include a vertical is discussed in relation to the vertical–horizontal illusion, the function and structure of cortical orientation processes, and perceptual development.
Transparency: Relation to Depth, Subjective Contours, Luminance, and Neon Color Spreading
Authors: Nakayama Ken , Shimojo Shinsuke , Ramachandran Vilayanur S 
Published: January 2007

The perception of transparency is highly dependent on luminance and perceived depth. An image region is seen as transparent if it is of intermediate luminance relative to adjacent image regions, and if it is perceived in front of another region and has a boundary which provides information that an object is visible through this region. Yet, transparency is not just the passive end-product of these required conditions. If perceived transparency is triggered, a number of seemingly more elemental perceptual primitives such as color, contour, and depth can be radically altered. Thus, with the perception of transparency, neon color spreading becomes apparent, depth changes, stereoscopic depth capture can be eliminated, and otherwise robust subjective contours can be abolished. In addition, we show that transparency is not coupled strongly to real-world chromatic constraints since combinations of luminance and color which would be unlikely to arise in real-world scenes still give rise to the perception of transparency. Rather than seeing transparency as a perceptual end-point, determined by seemingly more primitive processes, we interpret perceived transparency as much a ‘cause’, as an ‘effect’. We speculate that the anatomical substrate for such mutual interaction may lie in cortical feed-forward connections which maintain modular segregation and cortical feedback connections which do not.
Pre-Attentive Detection of a Target Defined by Stereoscopic Slant
Authors: Holliday Ian E , Braddick Oliver J 
Published: January 2007

Does the visual system represent stereoscopic depth purely as a map of local disparities, or does it explicitly represent local relationships of disparity, such as disparity gradients? Experiments are reported in which visual search for a target containing the same disparity range as other elements in the display, but differing in the relationship of the disparities (stereo slant), was used to determine whether the target showed ‘pop-out’ like a unitary feature, or the serial search characteristic of feature conjunctions. Each stereo pair of elements was selected randomly from a range of outline parallelograms leaning to the right or to the left, so that the target could not be identified using any monocular shape cue. Response times for detection of the target (present on 50% of the trials) were independent of the number of elements in the display. This result was confirmed by varying element size and spacing, and by using oblique crosses rather than parallelograms as stimuli. It is concluded that stereoscopically defined slant, or disparity gradient, can be processed and compared in parallel across the display, and acts in this respect as an explicit unitary visual property. This contrasts with findings in analogous experiments on movement, which show that targets defined by divergence or deformation of optic flow can only be identified by serial search.
Mobility of Normal Observers under Conditions of Reduced Visual Input
Authors: Eyeson-Annan Margo , Brown Brian 
Published: January 2007

The importance in mobility performance of the rate of presentation of visual information, binocular versus monocular vision, the use of multiple rather than single reference points, and local motion parallax was investigated in two experiments. In each experiment ten subjects walked a triangular mobility course in a totally darkened room; the only visible targets were light emitting diodes (LEDs), mounted on poles, at the apices of the triangle. The LEDs were mounted so that one or two could be used in a trial; if two were used the distance between them was varied horizontally (in experiment 1) and vertically (in experiment 2). The subjects walked around the course under a range of conditions, including two ‘optimal trials’ in full light. The LEDs were flashed for 1 ms at frequencies of 0.5, 1 and 5 Hz in experiment 1 and at 1 and 5 Hz in experiment 2. Mobility was measured with the use of an ultrasonic locator system which measured the subject's position on the course 10 times per second. The mean velocity of the subject in traversing the course was significantly reduced when the flash rate was slower, when the subject had one eye occluded, or when there was only one LED on the pole; when the spacing between the LEDs was varied, either vertically or horizontally performance was unaffected. These results imply that the frequency of updating of visual information is important in determining mobility performance, as are binocular cues, but that local motion parallax is not important. The number of LEDs on each pole had a significant effect on mobility performance: an ‘object’ (two lights) gave more information than a point reference.
Visual Recognition in the Peripheral Field: Letters versus Symbols and Adults versus Children
Authors: Zegarra-Moran Olga , Geiger Gad 
Published: January 2007

The plot of the form-resolving field (FRF) was obtained by tachistoscopically presenting two figures in each stimulus, one in the center of gaze and the other in the peripheral field. The figures in the periphery were placed at various eccentricities in different presentations. The ensuing plot of average letter recognition as a function of eccentricity is the FRF. Only the horizontal components of the FRFs were used in the comparisons. Three sets of figures were used as stimuli: regular-size letters, large-size letters, and symbols. Three groups of subjects were compared: adult ordinary readers, reading children, and pre-reading-age children. The last were tested with symbols only. In letter recognition, the FRFs for young and adult ordinary readers are similar and fall off monotonically and symmetrically with eccentricity, hence conforming with the first Aubert—Foerster law (1857). However, the FRFs tested with symbols are narrower than those tested with letters of the same sizes and stroke widths, which is not in accordance with the first Aubert—Foerster law. In addition, the FRFs of symbols are different for each subject group. It is suggested that recognition in the peripheral field is not determined by visual acuity alone; rather, it is further confined or determined by the visual strategy employed to accomplish the task, and its associated distribution of lateral masking.
Up–down Asymmetry in Vertical Induced Motion
Authors: Lott Lori A , Post Robert B 
Published: January 2007

Induced motion (IM) is the illusory movement of an object in the direction opposite to the real motion of adjacent detail. One theory of IM suggests that it results, in part, from suppression of optokinetic nystagmus (OKN) by fixational (smooth-pursuit) effort. In several studies an asymmetry in human vertical OKN has been reported, with upward optokinetic stimulation eliciting higher OKN gain than downward motion. This provides a test of the nystagmus-suppression theory of IM. If suppression of OKN contributes significantly to IM, upward inducing stimuli should result in a greater magnitude of the illusion than should downward stimulus motion. Additionally, the asymmetry of vertical OKN should become more pronounced at higher stimulus velocities. Therefore, the asymmetry of vertical IM should be greater at higher inducing-stimulus velocities. Twelve subjects viewed a large, random-dot stimulus, which moved either upward or downward at a velocity of 10, 40, or 70 deg s−1. Subjects fixated a horizontally moving laser spot and adjusted a rod to match the apparent slope of the motion path of the spot. IM magnitude was derived from these measures. Mean IM velocity was significantly higher with upward than with downward stimulation, and the difference was maximal at velocities of 40 and 70 deg s−1. The results are discussed within the context of the nystagmus-suppression theory and other theories of IM.
Independent Effects of Lighting, Orientation, and Stereopsis on the Hollow-Face Illusion
Authors: Hill Harold , Bruce Vicki 
Published: January 2007

Three experiments were conducted to investigate factors contributing to the ‘hollow face’ illusion. A novel method was employed in which the distance from the mask at which the illusion became apparent or disappeared, when retreating or approaching, respectively, was taken as a measure of the strength of the illusion. In all the experiments an effect of direction of observer's movement was found, demonstrating the stability of the initial percept. Upright orientations were compared with inverted ones to investigate if the illusion reflects a bias towards a familiar percept. The direction of lighting was also varied. Independent main effects of orientation and lighting were found to be consistent with preferences both for upright faces and for top lighting. However, inverted faces also produced the illusion to some extent, suggesting a general preference for convexity. The role of stereopsis in resolving the illusion was tested by comparing monocular with binocular viewing conditions. Monocular viewing conditions gave rise to shorter distances, suggesting that the retinal disparities available with binocular viewing are important in disambiguating the illusion at small distances. The results are interpreted within the framework of a 22-dimensional sketch derived from independent modular processing of visual information.