Visually produced locomotion in an autokinetic setup.
Explore the source record for details and available documents.
Cues↗
SEARCH · Search PubMed
Results for “Distance 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.
Contrast and assimilation in the Baldwin illusion.
Four experiments were conducted to investigate the role of "large" squares on the occurrence of assimilation and contrast in the Baldwin illusion. In Exps. 1 and 2, in which subjects reproduced the length of the test line, large squares induced illusions of assimilation. In Exp. 3, reproduction of the entire length of the test line also resulted in illusions of assimilation but bisection of the test line and reproduction of one-half the length of the test line resulted in contrast. Exp. 4 replicated the findings involving judgments of one-half the length of the test line. Over-all, the results indicate that judgments of one-half the length of the test line result in contrast, whereas judgments of the entire extent result in assimilation.
Adult↗
Effects of training and visual distance on speechreading performance.
The purpose of this study was to investigate the effects of training on subjects' ability to speechread sentences at varying visual distances of 3-6 ft., 6-12 ft., and 12-18 ft. 15 college women who received training obtained higher sentence speechreading scores than the 15 untrained women. The emphasis placed on kinesthetic feedback may have assisted the trained subjects' performance; however, distance up to 18 ft. did not appear to affect subjects' ability to speechread sentences, regardless of training.
Adult↗
The registered distance of the celestial sphere: some historical cross-cultural data.
Estimates of the diameters of the sun and moon expressed in centimetres have been reported by several authors in the past. These estimates imply that the sizes of the sun and moon are perceived as if these bodies are only some tens of metres distant. In this study five units of length that were used by ancient astronomers to estimate arcs on the celestial sphere were investigated. The purpose was to determine whether the lengths and angles represented by these units imply a specific registered distance of the star sphere. The sizes of the Babylonian cubit, Arab fitr and shibr, Greek eclipse digit, and Chinese chang support the conclusion that the registered distance of the stars was about 10 to 40 metres in these four cultures over the last two millennia.
Astronomy↗
Effect of starting position on reproduction of movement: further evidence of interference between location and distance information.
Two experiments done with a short-term memory paradigm examined the influence of shifts in the starting position on the reproduction of kinesthetic location (Exp. 1) and on distance cues (Exp. 2). We assessed possible causes of the systematic pattern of undershooting and overshooting as related to the shift in the starting position. In each experiment, two groups of 10 students were given 25 trials, and each had criterion and reproduction tasks involving linear-positioning movements with a 10-sec. retention interval. Each experiment had two independent variables, the group of subjects and the shift in the starting position. The two groups differed in the possible sources of information, the distance moved (Exp. 1) or the end-location (Exp. 2), which were assumed to cause undershooting and overshooting during reproduction. Analysis showed that the information about the distance moved may produce undershooting and overshooting in reproduction of the end-location (Exp. 2). Also, the information about the end-location may produce undershooting and overshooting in reproduction of the distance moved (Exp. 2). The findings were further evidence of interference between location and distance cues in motor short-term memory.
Cues↗
Influence of phenomenal time on perceived space.
It is known from work by Helson and King that the apparent spatial distance between stimuli presented in succession depends on the time interval between those stimuli ("tau effect"). It is also known that the apparent time (i.e., the interval of time perceived between stimuli presented in succession) depends on the spatial distance between the stimuli defining the time interval (called "kappa effect" by Cohen, Hansel, and Sylvester). For the "kappa effect," apparent time between lights and stimuli on the skin of the forearm undergoes modification depending on the apparent spatial distance, as presented in Suto's work beginning in the early 1940s. The present work is complementary to Suto's. Its purpose is to test whether apparent spatial distance depends on the objective or subjective (apparent, phenomenal) time interval. To achieve this, our crucial (third) experiment was preceded by two exploratory experiments: the first to verify the illusion in which a subdivided interval appears longer than an empty interval of the same length (Oppel-Kundt temporal illusion); the second to verify the presence of the "tau effect" with simultaneous tactual and auditory stimuli for time intervals between 1500 and 2500 msec. In the third experiment subjects received successive tactual stimuli defining two spatial distance and two time intervals. They also received auditory stimuli that produced the Oppel-Kundt illusion by making the time intervals phenomenally different. The results fill a small experimental gap by showing it is subjective (phenomenal) and not objective (physical) time that influences perceived spatial distances.
Adolescent↗
Attention and the Müller-Lyer illusion: simulation of an experiment by Larsen and Garn.
Explore the source record for details and available documents.
Attention↗
Visual cues and attention demand in locomotor positioning.
The aim of this study was to determine what visual cues are used to assess the time-to-contact (Tc) with a stationary target during locomotor positioning. For this purpose, we performed an experiment with restricted central visual cues and analysed the attention demand involved in use of visual cues. 11 subjects were asked to walk towards a target surface and stop in front of it. Two target sizes were used: the tau strategy, consisting of assessing Tc from the relative expansion rate of the target during locomotion, was possible only with the larger one. The same task was also performed in a dual-task situation wherein reaction time to auditory stimuli was recorded. Analysis showed that braking was initiated earlier only in the dual-task situation involving the small target. The secondary task reaction time also increased considerably and actually even sooner when the positioning was done on the small target. These results suggest that a strategy other than tau may be used to assess Tc: with this strategy, the braking distance and walking speed are taken into account. Furthermore, different processing levels must have been involved in these two different methods, since the attention demand differed from one positioning task to the other.
Adult↗
Conservation of distance in African children from rural and urban schools.
This paper contains a review of the small literature on the association of rural/urban residence and attainment of distance conservation among African children and an account of a study of the age at which children in Sierra Leone, West Africa, attain conservation. 150 children from the ages of 8 to 18 years, from rural and urban schools, were assigned Piagetian tasks to judge their conservation of distance. Analysis showed that at 11 + years, conservation was observed and that there was no significant difference between the urban sample and the rural one. Several confounds in the data limit conclusions but use of the children's own languages was possible in some experiments.
Child↗
The eyes in imagery and perceptual processes: first remarks.
Through an echographic system we examined the activity of the crystalline lens of 10 men and women during real perceptual activity and during imagery. Subjects had to perceive near and far stimuli and to imagine reading a word on a page of a book (near imagined stimulus) or seeing a ship on the horizon (far imagined stimulus). Results showed that processes of accommodation (linked to the variations of the optical axis of the crystalline lens) occur in both real and imaginative conditions. The first results suggest an active role of the eye during imagery.
Accommodation, Ocular↗
Concept mapping of movement-related knowledge.
Concept mapping was developed by Novak and Gowin in 1984 as a technique to examine an individual's knowledge-base in a given domain. In the motor domain, however, with a heavy emphasis on automated and tacit knowledge there may not be a base of information which can be verbally reported. 52 subjects with similar academic backgrounds were asked to explain all they knew about the concept of movement, and these reports were transcribed and assessed by four judges. Subjects also completed a pattern-recognition task related to procedural knowledge for movement. Over-all, the judges were able to identify a clear hierarchy in the levels of movement-related knowledge, suggesting that this technique may be useful in research on movement. However, this declarative knowledge appeared to be distinct from associated procedural knowledge, supporting Anderson's (1982) theory and the need for several tools to provide a more complete reflection of the knowledge base in a particular domain.
Acceleration↗
Is spatial judgement of ball trajectories a highly differentiated or hierarchically organized skill?
An experiment was designed to examine the structure of spatial judgement skill related to ball trajectories. 54 subjects (16 to 23 years old) were administered prediction tasks in two highly contrasted planes (saggital vs fronto-parallel) and a speed of visual-discrimination task. Factor analysis shows that the skill is hierarchically organized with a broad-spectrum factor which covers the whole range of perceptual conditions and two group factors, one per trajectory plane. The low magnitude of the partial correlations between Inspection Time and Prediction Tasks (with simple reaction time kept constant) was interpreted as a confirmation of the hierarchical nature of the skill.
Adolescent↗
Effects of visualization and Danjeon breathing on target shooting with an air pistol.
This investigation was conducted to assess which technique, visualization, Danjeon breathing, or a combination of these, would be most effective in enhancing target shooting with an air pistol. 48 college students (28 men, 20 women) were selected and randomly assigned to one of four groups (ns = 12): control, visualization, Danjeon breathing, and visualization plus Danjeon breathing. Data were analyzed by a 4 x 5 (groups x days) analysis of variance with repeated measures on days. Both the combination of visualization plus Danjeon breathing and the Danjeon breathing alone were significantly better than the control on most of the measures of shooting performance.
Adolescent↗
A study of the application of Fitts' law to selected cerebral palsied adults.
Fitts' Law was applied to the evaluation of discrete aimed arm movements in one dimension performed by 6 adults with cerebral palsy and 6 adults with normal movement. Targets (1.27, 3.81, 6.35, 8.89 cm in width) placed at distances of 20.32, 30.48, 40.64, and 50.80 cm provided Indices of Difficulty of 2.19 to 6.32 bits. A video game was used for the signal to move. The t tests for corrected means showed that the cerebral palsied group had greater reaction and movement times than than the normal group. Linear regression analyses for pooled data and for the individual cerebral palsied subjects showed (a) no relationship between reaction time and Index of Difficulty for either group and (b) a negative, linear relationship between reaction time and Index of Difficulty for 1 cerebral palsied subject. Movement time was linearly and positively related to the Index of Difficulty for the normal group but not for the cerebral palsied group. Two cerebral palsied subjects had movement times which conformed to Fitts' Law. While the exceptions to Fitts' Law may be due to the limited range of movement and spasticity caused by severe cerebral palsy, there are indications that two of the cerebral palsied subjects were performing ballistic rather than visually guided aimed movements. Fitts' Law may still apply when the distances and target positions are individualized to conform to subjects' specific limitations and when the signal to move is auditory rather than visual.
Adult↗
Effect of fading knowledge of results on acquisition, retention, and transfer of a simple motor task.
Explore the source record for details and available documents.
Adult↗
Influence of looking at hazard lights on car-driving performance.
The purpose of the present study was to determine what effect (if any) looking at an automobile's hazard lights has on the direction in which a car is driven. Eight Japanese drivers participated in this experiment. Analysis indicated that (a) at night drivers passed closer to a forward-facing stationary car than during the day and (b) when instructions were given to look at the hazard lights of a forward-facing stationary car, drivers passed closer than when no such instructions were given or when the hazard lights were off. The relationship between looking at the visible targets in a visually poor environment and the direction in which a car is driven was discussed.
Adult↗
Visuospatial functions in patients with spasmodic torticollis.
Visuospatial functions were studied in 18 patients with spasmodic torticollis and 18 matched controls. Subjects were examined with respect to their judgement of the subjective vertical, personal and extrapersonal orientation, the discrimination of left and right, the ability to judge angles and distances, and a drawing task. Patients showed marked deficits in extrapersonal orientation and atypical displacement errors to the right when requested to set the subjective vertical. Results were largely independent of the clinical characteristics of the disease. The pattern of results was attributed to a subtle attention deficit underlying complex measures of visuospatial functions. This may reflect a discrete dysfunction of the striatal-frontal circuits at least in a subgroup of patients.
Attention↗
Figural characteristics associated with random appearance of dot patterns.
43 subjects judged the amount of visual randomness of dot patterns in two experiments. The properties of stimuli were changed from Exp. 1 to Exp. 2, but the common characteristics associated with visual randomness were found.
Attention↗