Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SIZE PERCEPTION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11Linked to original sources
PubMed2002

Work loss associated with increased menstrual loss in the United States.

OBJECTIVE: To estimate the effect of increased menstrual flow on the loss of work. METHODS: Heavy or otherwise abnormal menstrual bleeding is a common problem among women in the reproductive age range. Until now, there has been no evidence of its effect on absences from work. We used data from the National Health Interview Survey 1999, a personal interview household survey using a nationwide representative sample of the civilian noninstitutionalized population of the United States. Participants were 3133 women aged between 18 and 64 years who reported having a natural menstrual period in the last 12 months and in the last 3 months, never having taken medication containing estrogen (except past use of oral contraceptives), and never having been told that they had reproductive cancer. Analysis was performed using data from 2805 women, 373 having self-described heavy flow and 2432 having normal flow. The main outcome measure was work loss associated with the degree of menstrual flow. RESULTS: Using binary logistic regression, age, marital status, education, family size, perception of health, and flow of menstrual periods are associated with work losses (P <.05). The odds ratio of 0.72 (95% confidence interval 0.56, 0.92) indicates that women who have a heavier flow are 72% as likely to be working as are women who have a lighter or normal flow. CONCLUSION: Menstrual bleeding has significant economic implications for women in the workplace: work loss from increased blood flow is estimated to be $1692 annually per woman.

Absenteeism↗
PubMed1997

Pitfalls in estimating motion detector receptive field geometry.

A number of psychophysical investigations have used spatial-summation methods to estimate the receptive field (RF) geometry of motion detectors by exploring how psychophysical thresholds change with stimulus height and/or width. This approach is based on the idea that an observer's ability to detect motion direction is strongly determined by the relationship between the stimulus geometry (height and width) and the RF of the activated motion detectors. Our results show that previous estimates of RF geometry can depend significantly on stimulus position in the visual field as well as on the stimulus height-to-width ratio. The data further show that RF estimates depend on the stimulus in a manner that is inconsistent with basic predictions derived from current motion detector models. Hence previous estimates of height, width, and height-to-width ratios of motion detector RFs are inaccurate and unreliable. This inaccuracy/unreliability is attributed to a number of sources. These include incorrect fixed-parameter values in model fits, as well as the confounding of physiological spatial summation area through combined use of contrast thresholds and Gaussian-windowed stimuli. A third source of error is an asymmetric variation of spatiotemporal correlation in the stimulus as either its height or width is varied (and the other dimension held constant). Most importantly, a fourth source of unreliability is attributed to the existence of a nonlinear, nonmonotonic distribution of motion detectors in the visual field that has been previously described and is a natural result of visual anatomy.

Contrast Sensitivity↗
PubMed1980

Variability and sequential effects in cross-modality matching of area and loudness.

Individual subjects' performance was examined for cross-modality matching (CMM) of loudness to visual area, as well as for magnitude estimation (ME) of the component continua. Average exponents of power functions relating response magnitude to stimulus intensity were .73 for area, .20 for loudness, and 2.44 for CMM. Predictions of the CMM exponent based on ME were higher than the empirical values, whereas more accurate predictions were made from magnitude production exponents obtained in a previous study. Sequential dependencies were assessed by comparing the response on trial n to the response on trial n--1. The coefficient of variation of the response ratio Rn/Rn-1 was systematically related to the stimulus ratio Sn/Sn-1 for both area and loudness. The coefficient was lowest for ratios near 1 and increased for larger or smaller values. For CMM, the coefficient of variation appeared to be independent of stimulus ratios. The correlation between log Rn and log Rn-1 was also related to Sn/Sn-1 for both ME and CMM. The correlation was highest when Sn/Sn-1 was 1 and dropped to 0 with increasing stimulus separation, but CMM yielded a shallower function than ME.

Adult↗
PubMed2005

The role of feedback information for calibration and attunement in perceiving length by dynamic touch.

Two processes have been hypothesized to underlie improvement in perception: attunement and calibration. These processes were examined in a dynamic touch paradigm in which participants were asked to report the lengths of unseen, wielded rods differing in length, diameter, and material. Two experiments addressed whether feedback informs about the need for reattunement and recalibration. Feedback indicating actual length induced both recalibration and reattunement. Recalibration did not occur when feedback indicated only whether 2 rods were of the same length or of different lengths. Such feedback, however, did induce reattunement. These results suggest that attunement and calibration are dissociable processes and that feedback informs which is needed. The observed change in variable use has implications also for research on what mechanical variables underlie length perception by dynamic touch.

Adult↗
PubMed2000

The spatial spread of attentional modulation of the motion aftereffect.

The spatial spread of attentional modulation of selective adaptation was investigated in four experiments in which the duration of the movement aftereffect (MAE) was measured with and without processing of intermittently changing digits at the fixation point. In the first experiment, the effects of diverting attention on MAE duration were found to reduce as the distance between the fixation digits and the inner edge of the surrounding adapt/test grating was increased. A second experiment suggested that eye movements were unlikely to underlie the attentional effects. In experiment 3, the attentional effect stayed constant as the outer diameter of the adapt/test gratings was increased. In experiment 4 (as in experiment 1) the modulatory effects of attention were larger the closer the adapt/test gratings were to the locus of attention, when the area of the grating was held constant but its eccentricity varied. In experiments 1 and 4, an intermittently changing fixation digit was found to reduce MAE durations more than an unchanging digit, even when subjects were not required to process it, suggesting that exogenous as well as endogenous attentional processes modulate early motion processing.

Attention↗
PubMed2003

Intra- and interactive touch on the face.

Experiments were performed in which the subjective size of steel balls was judged by the method of absolute magnitude estimation (AME). The balls were rolled actively ("scripting") by the right index finger pad of the subject over the passively receiving areas of the face, namely the forehead, cheek and the vermilion border of the lower lip. These areas were stimulated on the subject's own person (intra-active touch), on another person's face (interactive touch) and by another person upon the face of the subject (interactive touch). Results indicate that size perception appears to be governed primarily by the mechanical characteristics of the stimuli, including the balls and the sites on the face. When the subject's finger was used to script upon another's face, there were significant differences among or between the sites. When another person scripted upon the subject's face there were no significant differences among any of the sites. The results are discussed considering mode of stimulation and tissue mechanics.

Cheek↗
PubMed1996

On orienting the hand to reach and grasp an object.

Subjects were required to reach and grasp a parallelepiped, the position, orientation and size of which were varied. The kinematics of reaching and grasping movements was studied in full vision and in no vision conditions. Both direction and movement amplitude of reaching were affected by object orientation. Conversely, both the time course of finger axis orientation and the angular displacement of the hand at wrist were influenced by object position. These results were not modified by the absence of visual control. Finger aperture during grasping was affected by both object size and orientation. This latter result was not due to a distorted size perception, as shown by a control matching experiment. Taken together, the results of the present study suggest the integration between distal and proximal components during reaching and grasping.

Adult↗
PubMed1991

Body-image marking. Validity of body-width estimates as operational measures of body image.

The relation of image-marking estimates of body width (IM) to actual widths, to other indices of body-size perception, and to measures of body satisfaction were examined using data obtained in a nonclinical sample of 200 women. The results of regression and correlational analyses were as follows: (a) actual widths accounted for only a small proportion of the variance in IM estimates, (b) the variance in IM estimates remaining after actual width was accounted for was not meaningfully related to other body-image indices, and (c) actual widths were more highly correlated with other body-image indices than were differences between estimated and actual widths (IM estimate-actual width). The current results suggest that most of the variance in IM estimates is error variance. Possible methodological confounds, which may bias women's estimates of body widths in the direction of overestimation, are discussed.

Adult↗
PubMed1995

Development and validation of a new body-image assessment scale.

This investigation reports the development and validation of a new and improved body-image assessment tool, the Contour Drawing Rating Scale, consisting of nine male and nine female contour drawings. The drawings were designed with detailed features, are of precisely graduated sizes, and are easily split at the waist for accurate upper and lower body comparisons. Initial evidence of the scale's reliability and validity supports its use as a measure of body-size perception.

Adolescent↗
PubMed1994

Attitudes toward body size and dieting: differences between elderly black and white women.

Eating restraint and body size perceptions of 404 White and African-American women 66 to 105 years of age (mean age = 73 years) were assessed by questionnaire. Compared with overweight White women, overweight Black women were 0.6 times as likely to feel guilty after overeating, 0.4 times as likely to diet, 2.5 times as likely to be satisfied with their weight, and 2.7 times as likely to consider themselves attractive. Among those who were not overweight, Black women were half as likely as White women to consider themselves overweight. Compared with Black women, White women perceived themselves to be larger and reported a lower ideal body weight.

Black or African American↗
PubMed1994

Marketing and psychophysics: cornflakes and Stevens' power function.

Although major firms do not publish their pricing and packaging strategies, an analysis of 83 pairs of boxes of breakfast cereals using Stevens' Law showed that firms price their products on the perception of size rather than by actual size. By contrast, laundry detergents are priced by actual weight and volume.

Choice Behavior↗
PubMed2005

An interval size illusion: the influence of timbre on the perceived size of melodic intervals.

In four experiments, we investigated the influence of timbre on perceived interval size. In Experiment 1, musically untrained participants heard two successive tones and rated the pitch distance between them. Tones were separated by six or seven semitones and varied in timbre. Pitch changes were accompanied by a congruent timbre change (e.g., ascending interval involving a shift from a dull to a bright timbre), an incongruent timbre change (e.g., ascending interval involving a shift from a bright to a dull timbre), or no timbre change. Ratings of interval size were strongly influenced by timbre. The six-semitone interval with a congruent timbre change was perceived to be larger than the seven-semitone interval with an incongruent timbre change (interval illusion). Experiment 2 revealed similar effects for musically trained participants. In Experiment 3, participants compared the size of two intervals presented one after the other. Effects of timbre were again observed, including evidence of an interval illusion. Experiment 4 confirmed that timbre manipulations did not distort the perceived pitch of tones. Changes in timbre can expand or contract the perceived size of intervals without distorting individual pitches. We discuss processes underlying interval size perception and their relation to pitch perception mechanisms.

Humans↗
PubMed2006

Motion onset captures attention: a rejoinder to Franconeri and Simons (2005).

Recently, we have provided evidence that the onset of motion captures attention (Abrams & Christ, 2003, 2005a, 2005b). In the present article, we clarify the motion onset hypothesis, we discuss recent data (Franconeri & Simons, 2005) that, at least on the surface, seem to challenge the hypothesis, and we present results from a new experiment (Christ & Abrams, 2005). Finally, we conclude that, although motion onset does indeed appear to capture attention, motion in the absence of a motion onset might also attract attention under certain circumstances.

Attention↗