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PubMed1994

What is a crucial determinant in anorthoscopic perception?

There are two important problems in anorthoscopic perception. The first is how a sequence of parts of a figure viewed through a slit is integrated into a whole. The second is how the distortion of an anorthoscopic image along the direction of its motion occurs. To answer the questions, two experiments and two demonstrations were performed by conceiving compound figures of one horizontal and one curvilinear component and a method which permits seeing anorthoscopic and ordinary images at the same time. From the results, the idea of anorthoscopic motion complementary to apparent motion is introduced as a crucial determinant that permits an integration of the parts into a perception of the whole. As regards the distortion of the percept we agree with Rock, et al.'s 1987 assumption but also consider that the distortion depends on the ratio of speed of anorthoscopic motion to real motion.

Attention↗
PubMed1998

Implicit and explicit memory in individuals with mental retardation.

Students with and without mental retardation from three age groups were compared on implicit and explicit memory tasks. Consistent with previous research on intelligence-related differences in controlled and automatic processes, students without mental retardation performed better than those with mental retardation on the explicit memory task, but there was no difference between groups on the implicit memory task. For both groups implicit and explicit memory increased from age 6 to 8 to age 10 to 12, but did not significantly increase to age 15 to 17. Because implicit memory appears to be a relative strength for students with mental retardation, we suggest further exploration into broader types of implicit processes that may be useful in training situations.

Adolescent↗
PubMed2004

Point-light biological motion perception activates human premotor cortex.

Motion cues can be surprisingly powerful in defining objects and events. Specifically, a handful of point-lights attached to the joints of a human actor will evoke a vivid percept of action when the body is in motion. The perception of point-light biological motion activates posterior cortical areas of the brain. On the other hand, observation of others' actions is known to also evoke activity in motor and premotor areas in frontal cortex. In the present study, we investigated whether point-light biological motion animations would lead to activity in frontal cortex as well. We performed a human functional magnetic resonance imaging study on a high-field-strength magnet and used a number of methods to increase signal, as well as cortical surface-based analysis methods. Areas that responded selectively to point-light biological motion were found in lateral and inferior temporal cortex and in inferior frontal cortex. The robust responses we observed in frontal areas indicate that these stimuli can also recruit action observation networks, although they are very simplified and characterize actions by motion cues alone. The finding that even point-light animations evoke activity in frontal regions suggests that the motor system of the observer may be recruited to "fill in" these simplified displays.

Adult↗
PubMed2006

Boundary completion is automatic and dissociable from shape discrimination.

Normal visual perception readily overcomes suboptimal or degraded viewing conditions through perceptual filling-in processes, enhancing object recognition and discrimination abilities. This study used visual evoked potential (VEP) recordings in conjunction with electrical neuroimaging analyses to determine the spatiotemporal brain dynamics of boundary completion and shape discrimination processes in healthy humans performing the so-called "thin/fat" discrimination task (Ringach and Shapley, 1996) with stimuli producing illusory contours. First, results suggest that boundary completion processes occur independent of subjects' accuracy on the discrimination task. Modulation of the VEP to the presence versus absence of illusory contours [the IC effect (Murray et al., 2002)] was indistinguishable in terms of response magnitude and scalp topography over the 124-186 ms poststimulus period, regardless of whether task performance was correct. This suggests that failure on this discrimination task is not primarily a consequence of failed boundary completion. Second, the electrophysiological correlates of thin/fat shape discrimination processes are temporally dissociable from those of boundary completion, occurring during a substantially later phase of processing (approximately 330-406 ms). The earlier IC effect was unaffected by whether the perceived contour produced a thin or fat shape. In contrast, later time periods of the VEP modulated according to perceived shape only in the case of stimuli producing illusory contours, but not for control stimuli for which performance was at near-chance levels. Collectively, these data provide further support for a multistage model of object processing under degraded viewing conditions.

Adult↗
PubMed2005

Effects of script types of Japanese loan words on priming performance.

23 female undergraduate students (M=20 yr., 10 mo., SD=15 mo.) were given a word-fragment completion task, containing a study and nonstudy list. In the present study, the effect of orthographic familiarity (e.g., script type) of a test item on a word-fragment completion task was examined. The script types of word stimuli (Katakana and Hiragana) were manipulated between a study and test phase. Priming effect was greater when the script type was the same between a study and test phase than in the cross-script condition. Further, even if the script type of word stimulus was different between study and test phases, a significant priming effect was obtained when the test fragment was orthographically familiar. These results suggested that not only the consistency of the perceptual feature of the stimulus word between study and test phases, but also orthographic familiarity of the stimulus word in the test phase facilitated priming effect in a word-fragment completion test.

Adult↗
PubMed2005

A qualitative analysis of inaccurate responses on the Hooper Visual Organization Test.

The present study investigated the types of inaccurate responses, i.e., Don't Know, Semantic, Visual (nonlinguistic), Phonological, Circumlocutory, and Perseverative, made on the Hooper Visual Organization Test by a heterogeneous sample of 68 brain-damaged and 63 substance abuse patients. The mean age of the brain-damaged and substance abuse groups were 46.0 (SD=13.5) and 43.7 (SD=12.9) yr., respectively. Analysis showed that the brain-damaged group made significantly more visual and perseverative responses than the substance abuse group. There was significantly more variance in the Visual responses than the Semantic responses for the brain-damaged group. The authors conclude that visuospatial ability is the primary factor for successful performance on this test.

Adult↗
PubMed2006

Surface location and enclosure.

This research addressed the issue of whether impressions of enclosure were more strongly influenced by amount of view covered by vertical boundaries (H1) or the presence of a boundary overhead (H2). There were three studies with totals of 48 stimuli and 142 respondents. Stimuli were balconies, swamps, and space stations. Effect sizes were reported for variables of boundaries below, in front of, and at the observers' sides, as well as amount of view covered by any boundary regardless of location with respect to the observer. Judged enclosure correlated at r =.80 for amount of view covered by vertical boundaries and r =.42 with the presence or absence of boundaries overhead, indicating that enclosure is more strongly related to vertical rather than overhead boundaries (alpha< .001).

Adolescent↗
PubMed1975

Delay in retention of forms.

10 forms were drawn on the palms of 48 subjects who were without vision. Subjects were then required haptically to explore three forms and choose the drawn shape. Three intervals, 0, 5, and 15 sec., were inserted between the presentation of the drawn form and the choice. It was expected that there would be a decline in the accuracy of form recognition with an increase in delay. Form recognition was significantly superior with no delay and loss of shape information seems to occur rather quickly since there was no significant difference in the accuracy of form recognition between the two longer delays.

Female↗
PubMed1980

Factor analysis of perceptual and cognitive abilities tested by different methods.

A battery of visual, perceptual, and cognitive tests, believed to be important for operation of visual sonar displays, was administered to 100 sonar technicians. The measures varied from standard paper-and-pencil tests to computer-administered perceptual tasks. The results of 33 different measures on these men were compiled and subjected to a factor analysis. The factors extracted represent cohesive and reasonable groups which cut, to some extent, across testing techniques. However, all of the paper-and-pencil, perceptual-cognitive tests had high loadings on the same common factor, a result with general implications for occupational testing.

Adult↗
PubMed1981

Correlational structure as a determinant of goodness of complex patterns.

The stimulus sets used by Whitman and Garner (1962) to study the effect of form of redundancy on free-recall learning were arranged in 3 X 3 configurations to form single patterns. Various spatial arrangements of the 9 figures in each of the 3 sets tested several questions regarding judged goodness of form. Rating of goodness of form on a 7-point scale were made by 32 college students. Patterns composed of elements which have correlated structure in the form of simple contingencies, and which Whitman and Garner found were easily learned in free recall, are good; patterns composed of elements which have correlational structure in the form of complex interactions, and which Whitman and Garner found were extremely difficult to learn, are not. Uncertainty calculated for spatial position using 2-dimensional Cartesian coordinates as variables does not appear to be associated with pattern goodness. However, spatial arrangements of the elements exert a very strong effect on pattern goodness.

Adult↗
PubMed1982

Mathematical model for the filling-in of illusory contour.

It is demonstrated that illusory contour in the shape of a square is perceived lighter when abutted by black horizontal lines and white vertical lines, darker when abutted by white horizontal lines and black vertical lines. These differences in perceived brightness and the spread of brightness, or a filling-in phenomenon, can be modeled by the major product of a column vector and a row unit vector where the order of each vector corresponds to extent and the value of each entry in the column vector corresponds to brightness.

Discrimination Learning↗
PubMed1982

Visual information processing at the blind spot.

The perceptual completion at the blind spot was studied by presenting test patterns around the blind area of 3 subjects with normal acuity, and conditions generating the perceptual completion were investigated. To be filled in, a stimulus must fall on at least two quadrants around the blind spot. Both a region between 3.0 and 3.9 degrees in radii around the blind spot, which can generate white homogeneous completion, and the region between 4.3 and 5.2 degrees, which can not generate any completion solely, play important parts in provoking completion. Periodic stimuli were more effective than non-periodic ones.

Humans↗