Interactions of chromaticity and luminance in edge identification depend on chromaticity

2004 ◽  
Vol 21 (3) ◽  
pp. 377-382
Author(s):  
VIVIANNE C. SMITH ◽  
JOEL POKORNY
Keyword(s):  
Fundamental Frequency ◽  
Forced Choice ◽  
The Other ◽  
Linear Summation ◽  
End Points ◽  
Probability Summation ◽  
Compound Stimuli ◽  
Additive Control

The goal of this work was to study interactions of chromaticity and luminance in edge identification. Two horizontal spatial sawtooth patterns, one with positive and the other with negative harmonics, were compared in a two-alternative forced-choice (2-AFC) procedure. The observer identified which pattern had sharp upper or lower edges. The fundamental frequency was 2 cycles/deg (cpd), with 5 cycles presented in a 2.5-deg square field. The pattern was presented as a 1-s raised temporal cosine, replacing part of an 8-deg background. Stimuli were specified in a cone troland (l, s, Y) chromaticity space, with correction for individual equiluminance at a nominal 115 td, and individual tritan direction. A preliminary set of interleaved staircases established edge identification for the six directions of the (l, s, Y) space. Three compound stimuli combining two orthogonal directions were chosen and included with the end-points in five randomly interleaved staircases. For combinations of Y with l-chromaticity, or l- with s-chromaticity, probability summation was observed. Combinations of Y with s-chromaticity revealed opponency. Data for +s, +Y and −s, −Y were subadditive; data for +s, −Y and −s, +Y were additive. Control studies using detection rather than edge identification revealed probability summation for all combinations. Luminance edges did not enhance stimuli with l-chromaticities. There was an interaction of luminance edges with s-chromaticities. Dim “blues” and bright “yellows” showed linear summation. Bright “blues” and dim “yellows” showed opponency.

Intonational differences between the reduplicative babbling of French- and English-learning infants

1991 ◽  
Vol 18 (3) ◽  
pp. 501-516 ◽  
Author(s):  
D. H. Whalen ◽  
Andrea G. Levitt ◽  
Qi Wang
Keyword(s):  
Fundamental Frequency ◽  
The Other ◽  
English Learning ◽  
Complex Contour ◽  
Language Groups ◽  
French And English ◽  
Target Languages ◽  
Perceptual Assessment ◽  
Language Environment

ABSTRACTThe two- and three-syllable reduplicative babbling of five French-learning and five English-learning infants (0;5 to 1; 1) was examined in two ways for intonational differences. The first measure was a categorization into one of five categories (RISING, FALLING, RISE-FALL, FALL-RISE, LEVEL) by expert listeners. The second was the fundamental frequency (F0) from the early, middle and late portion of each syllable. Both measures showed significant differences between the two language groups. 65% of the utterances from both groups were classified as either rising of falling. For the French children, these were divided equally into the rising and the falling categories, while 75% of those utterances for the English children were judged to have falling intonation. Proportions of the other three categories were not significantly different by language environment. In both languages, though, three-syllable utterances were more likely to have a complex contour than two-syllable ones. Analysis of the F0patterns confirmed the perceptual assessment. Several aspects of the target languages help explain these intonational differences in prelinguistic babbling.

scholarly journals Combining Visual Contrast Information with Sound Can Produce Faster Decisions

2019 ◽  
Author(s):  
Birgitta Dresp-Langley ◽  
Marie Monfouga
Keyword(s):  
Response Times ◽  
Luminance Contrast ◽  
Forced Choice ◽  
Sound Frequency ◽  
Choice Response ◽  
Relative Depth ◽  
Probability Summation ◽  
Visual Contrast ◽  
Contrast Information ◽  
The Right

Pieron's and Chocholle’s seminal psychophysical work predicts that human response time to information relative to visual contrast and/or sound frequency decreases when contrast intensity or sound frequency increases. The goal of this study is to bring to the fore the ability of individuals to use visual contrast intensity and sound frequency in combination for faster perceptual decisions of relative depth (“nearer”) in planar (2D) object configurations on the basis of physical variations in luminance contrast. Computer controlled images with two abstract patterns of varying contrast intensity, one on the left and one on the right, preceded or not by a pure tone of varying frequency, were shown to healthy young humans in controlled experimental sequences. Their task (two-alternative forced-choice) was to decide as quickly as possible which of two patterns, the left or the right one, in a given image appeared to “stand out as if it were nearer” in terms of apparent (subjective) visual depth. The results show that the combinations of varying relative visual contrast with sounds of varying frequency exploited here produced an additive effect on choice response times in terms of facilitation, where a stronger visual contrast combined with a higher sound frequency produced shorter forced-choice response times. This new effect is predicted by cross-modal audio-visual probability summation.

Bayesian Comparison of Two Regression Lines

1978 ◽  
Vol 3 (2) ◽  
pp. 179-188
Author(s):  
Robert K. Tsutakawa
Keyword(s):  
Posterior Distribution ◽  
Prior Distribution ◽  
Posterior Probability ◽  
Finite Interval ◽  
Regression Line ◽  
The Other ◽  
End Points ◽  
Independent Variable

The comparison of two regression lines is often meaningful or of interest over a finite interval I of the independent variable. When the prior distribution of the parameters is a natural conjugate, the posterior distribution of the distances between two regression lines at the end points of I is bivariate t. The posterior probability that one regression line lies above the other uniformly over I is numerically evaluated using this distribution.

scholarly journals When regularization gets it wrong: children over-simplify language input only in production

2018 ◽  
Vol 45 (5) ◽  
pp. 1054-1072 ◽  
Author(s):  
Jessica F. SCHWAB ◽  
Casey LEW-WILLIAMS ◽  
Adele E. GOLDBERG
Keyword(s):  
Complex System ◽  
High Accuracy ◽  
Forced Choice ◽  
Choice Task ◽  
The Other ◽  
Natural Languages ◽  
Multiple Factors ◽  
Artificial Languages ◽  
Forced Choice Task ◽  
Unpredictable Variation

AbstractChildren tend to regularize their productions when exposed to artificial languages, an advantageous response to unpredictable variation. But generalizations in natural languages are typically conditioned by factors that children ultimately learn. In two experiments, adult and six-year-old learners witnessed two novel classifiers, probabilistically conditioned by semantics. Whereas adults displayed high accuracy in their productions – applying the semantic criteria to familiar and novel items – children were oblivious to the semantic conditioning. Instead, children regularized their productions, over-relying on only one classifier. However, in a two-alternative forced-choice task, children's performance revealed greater respect for the system's complexity: they selected both classifiers equally, without bias toward one or the other, and displayed better accuracy on familiar items. Given that natural languages are conditioned by multiple factors that children successfully learn, we suggest that their tendency to simplify in production stems from retrieval difficulty when a complex system has not yet been fully learned.

A simple random walk on parallel axes moving at different rates

1975 ◽  
Vol 12 (03) ◽  
pp. 466-476
Author(s):  
V. Barnett
Keyword(s):  
Random Walk ◽  
Simple Random Walk ◽  
Time Instant ◽  
Packed Columns ◽  
The Other ◽  
End Points ◽  
Previous Time ◽  
The Right

Prompted by a rivulet model for the flow of liquid through packed columns we consider a simple random walk on parallel axes moving at different rates. A particle may make one of three transitions at each time instant: to the right or to the left on the axis it was on at the previous time instant, or across to the other axis. Results are obtained for the unrestricted walk, and for the walk with absorbing, or reflecting, end-points.

Maternal Accommodation in Infant-Directed Speech during Mother's and Twin-Infants' Vocal Interactions

2003 ◽  
Vol 92 (2) ◽  
pp. 481-487 ◽  
Author(s):  
Katsuko Niwano ◽  
Kuniaki Sugai
Keyword(s):  
Fundamental Frequency ◽  
Acoustic Analysis ◽  
The Other ◽  
Vocal Response ◽  
Vocal Responses ◽  
Fraternal Twin ◽  
Maternal Speech ◽  
Vocal Interactions ◽  
Vocal Fundamental Frequency ◽  
At Home

In this study a mother's instinctive accommodations of vocal fundamental frequency (f0) of infant-directed speech to two different infants was explored. Maternal speech directed to individual 3-mo.-old fraternal twin-infants was subjected to acoustic analysis. Natural samples of infant-directed speech were recorded at home. There were differences in the rate of infants' vocal responses. The mother changed her f0 and patterns of intonation contour when she spoke to each infant. When she spoke to the infant whose vocal response was less frequent than the other infant, she used a higher mean f0 and a rising intonation contour more than when she spoke to the other infant. The result suggested that the mother's speech characteristic is not inflexible and that the mother may use a higher f0 and rising contour as a strategy to elicit an infant's less frequent vocal response.

scholarly journals Port retrieval for salvage of tissue expansion in case of lost or malfunctioning port

2010 ◽  
Vol 43 (02) ◽  
pp. 181-183
Author(s):  
Lalit K. Makhija ◽  
Manoj K. Jha ◽  
Sameek Bhattacharya ◽  
Ashish Rai ◽  
Sharad Mishra ◽  
...  
Keyword(s):  
Reconstructive Surgery ◽  
Tissue Expansion ◽  
The Other ◽  
End Points

ABSTRACTTissue expansion though a promising modality of reconstructive surgery is fraught with many complications. In addition to expander-related complications, subcutaneous port-related mishaps during tissue expansion, though infrequent, can result in procedure failures. We are reporting two patients with port-related complications. In one patient, there was failure to localise the port and the other had a leaking port. Both the expanders were salvaged by retrieving the ports. In the former, as the port was competent, it was simply exteriorised. But in the later case, the connecting tube was retrieved and the incompetent port was replaced with a Luer lock external port. Both the cases were successfully salvaged without any further complications. Expansions were completed and requisite reconstructive end points were achieved.

scholarly journals Intonational Patterns of Nonverbal Vocalizations in People With Dementia

2011 ◽  
Vol 26 (7) ◽  
pp. 563-572 ◽  
Author(s):  
Christina Samuelsson ◽  
Lars C. Hydén
Keyword(s):  
Disruptive Behavior ◽  
Fundamental Frequency ◽  
Acoustic Analysis ◽  
The Other ◽  
Clinical Settings ◽  
Pitch Range ◽  
Interactional Pattern ◽  
People With Dementia ◽  
Nonverbal Vocalizations ◽  
The Mean

Nonverbal vocalizations in dementia are important clinically since they generally have been regarded as disruptive behavior that is disturbing. The aim of the present study is to describe the interactional pattern, including the prosodic package, of nonverbal vocalizations in a participant in a late stage of dementia. The acoustic analysis shows that the vocalizations do not differ significantly from the verbal utterances regarding mean fundamental frequency or pitch range. The mean fundamental frequency, F0, of the utterances from Anna was significantly higher than the mean F0 from the other elderly participants. The analysis demonstrates that there is a singing-like type of vocalizations that does not resemble the previously described patterns of nonverbal vocalizations. This pattern of the nonverbal vocalization does not resemble the intonation of Anna’s verbal utterances. The other participants perceive Anna’s vocalizations as potentially meaningful turns. Nonverbal vocalizations in clinical settings should be taken as communicative contributions.

The relative contribution of segments and intonation to the perception of foreign-accented speech

2015 ◽  
Vol 37 (2) ◽  
pp. 303-322 ◽  
Author(s):  
JOAN SERENO ◽  
LYNNE LAMMERS ◽  
ALLARD JONGMAN
Keyword(s):  
Fundamental Frequency ◽  
Native Speakers ◽  
Native English Speakers ◽  
The Other ◽  
Foreign Accent ◽  
English Speakers ◽  
Relative Impact ◽  
Accented Speech ◽  
Relative Contribution ◽  
Accented English

ABSTRACTThe present study examines the relative impact of segments and intonation on accentedness, comprehensibility, and intelligibility, specifically investigating the separate contribution of segmental and intonational information to perceived foreign accent in Korean-accented English. Two English speakers and two Korean speakers recorded 40 English sentences. The sentences were manipulated by combining segments from one speaker with intonation (fundamental frequency contour and duration) from another speaker. Four versions of each sentence were created: one English control (English segments and English intonation), one Korean control (Korean segments and Korean intonation), and two Korean–English combinations (one with English segments and Korean intonation; the other with Korean segments and English intonation). Forty native English speakers transcribed the sentences for intelligibility and rated their comprehensibility and accentedness. The data show that segments had a significant effect on accentedness, comprehensibility, and intelligibility, but intonation only had an effect on intelligibility. Contrary to previous studies, the present study, separating segments from intonation, suggests that segmental information contributes substantially more to the perception of foreign accentedness than intonation. Native speakers seem to rely mainly on segments when determining foreign accentedness.

Measurements of Colour Constancy by Using a Forced-Choice Matching Technique

Perception ◽  
1996 ◽  
Vol 25 (2) ◽  
pp. 229-241 ◽  
Author(s):  
David I Bramwell ◽  
Anya C Hurlbert
Keyword(s):  
Forced Choice ◽  
The Other ◽  
Two Dimensional ◽  
Colour Constancy ◽  
Test Patch ◽  
Complex Scenes ◽  
Matching Technique ◽  
Chromatic Sensitivity ◽  
Colour Appearance ◽  
Method Of Constant Stimuli

Colour constancy is typically measured with techniques involving asymmetric matching by adjustment, in which the observer views two scenes under different illuminants and adjusts the colour of a reference patch in one to match a test patch in the other. This technique involves an unnatural task, requiring the observer to predict and adjust colour appearance under an illumination shift. Natural colour constancy is more a simple matter of determining whether a colour is the same as or different from that seen under different illumination conditions. There are also technical disadvantages to the method of matching by adjustment, particularly when used to measure colour constancy in complex scenes. Therefore, we have developed and tested a two-dimensional method of constant-stimuli, forced-choice matching paradigm for measuring colour constancy. Observers view test and reference scenes haploscopically and simultaneously, each eye maintaining separate adaptation throughout a session. On each trial, a pair of test and reference patches against multicoloured backgrounds are presented, the reference patch colours being selected from a two-dimensional grid of displayable colours around the point of perfect colour constancy. The observer's task is to respond “same” or “different”. Fitting a two-dimensional Gaussian to the percentage of “different” responses yields (1) the subjective colour-constancy point, (2) the discrimination ellipse centred on this point, and (3) a map of changes in sensitivity to chromatic differences induced by the illuminant shift. The subjective colour-constancy point measured in this way shows smaller deviations from perfect colour constancy—under conditions of monocular adaptation—than previously reported; discrimination ellipses are several times larger than standard MacAdam ellipses; and chromatic sensitivity is independent of the direction of the illuminant shift, for broad distributions of background colours.

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