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The prediction of visual collisionMole, G. January 1985 (has links)
No description available.
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Aging and Associative and Inductive Reasoning Processes in Discrimination LearningOrtz, Courtney 01 June 2006 (has links)
The purpose of this study was to investigate how associative and inductive reasoning processes develop over trials in feature positive (FP) and feature negative (FN) discrimination learning. Younger and older adults completed initial and transfer tasks with either consistent or inconsistent transfer. Participants articulated a rule on every trial. The measure of discrimination learning was the number of trials it took participants to articulate the exact rule. In the initial task, older adults articulated the rule more slowly than younger adults in FP discrimination and took marginally more trials to articulate the rule in FN discrimination than younger adults. Age differences were greater in FP discrimination than in FN discrimination learning because younger adults performed well in FP discrimination learning. In the transfer task, older adults articulated the FP rule more slowly than younger adults and both groups articulated the rule more quickly with consistent than inconsistent transfer. Older adults articulated the FN rule slower than older adults. The differences in trials to articulate the FN rule for the two groups were somewhat larger for inconsistent transfer than consistent transfer. Discrimination learning was explained in terms of associative and inductive reasoning processes reasonably well. The measure of associative processes was forgotten responses, whereas the measures of inductive reasoning processes were irrelevant cue shifts and perseverations. In FP discrimination learning in the initial task, older adults had a greater proportion of forgotten responses, irrelevant cue shifts, and marginally more perseverations than younger adults. Therefore, older adults had more difficulty with associative and inductive reasoning processes than younger adults in FP discrimination. In FN discrimination, older adults had a greater proportion of forgotten responses than younger adults. Older and younger adults had a similar number of irrelevant cue shifts and perseverations. Therefore, in FN discrimination older adults had more difficulty with associative processes than younger adults. Both groups had difficulty with inductive reasoning processes. In FP discrimination in the transfer task, older adults had a greater proportion of forgotten responses, irrelevant cue shifts, and perseverations than younger adults, and these proportions were similar in consistent and inconsistent transfer. Therefore, in FP discrimination older adults had more difficulty than younger adults with both associative and inductive reasoning processes. Both processes were similar with regards to consistent and inconsistent transfer. In FN discrimination, older adults had a greater proportion of forgotten responses than younger adults, and the proportion of forgotten responses was greater in inconsistent than in consistent transfer. Both groups made a similar number of irrelevant cue shifts, and there was a marginal difference in consistent and inconsistent transfer for this measure with a greater number in inconsistent transfer. Older adults had a greater proportion of perseverations than younger adults. However, there were no differences in the number of perseverations for consistent and inconsistent transfer. Thus, older adults had difficulty with associative and inductive reasoning processes. Younger adults' inductive reasoning skills improved. The associative and inductive reasoning processes in FN discrimination were not as efficient in inconsistent transfer as in consistent transfer.
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Memory for Non-Focal WordsJones, John 01 December 2006 (has links)
In two experiments a modified flanker paradigm was used to simultaneously present a focal word and an incidental non-focal word. The participants' task was to process the focal word in one of two conditions: naming aloud or a conceptual decision (concrete or abstract). The focal and non-focal words were either semantically related or not. Participants were instructed to direct their attention at the focal word. Furthermore, the presentation of the focal word was brief to reduce the possibility of eye movement to the non-focal word. Memory was measured with implicit and explicit memory tests. Evidence was found to suggest implicit memory traces were created for incidentally presented non-focal items, but explicit tests showed no sign of memory.
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Zebrafish Retinal Development and the Effects of Abnormal Light Rearing ConditionsSaszik, Shannon 01 August 1998 (has links)
Anatomical and physiological studies have shown that the zebrafish is a useful model of vertebrate visual function. Anatomy has shown that the zebrafish possess the traditional three cone types (S-, M-, and L- cones), and a fourth cone type that is sensitive to ultraviolet light (U-cones). Physiologically, the adult zebrafish appears to have a complex visual system with color opponent mechanisms. Anatomical results suggest that the zebrafish may be a good model of retinal development as well. The zebrafish retina develops in a sequential manner and is immature at hatch. Bilotta et al. (1996) also found that the retina was functionally immature in larvae zebrafish. In addition, after exposure to abnormal light rearing conditions, larvae zebrafish showed deficits in visual behavior, even though there appears to be no effect on the gross morphology of the young zebrafish retina. The purpose of the present study was to use a physiological approach to assess retinal development and the effects of abnormal light rearing conditions. Larvae zebrafish were raised under three light rearing conditions: constant light (LL), constant dark (DD), and normal cyclic light (LD) for six days following fertilization. After six days, the animals were placed back into normal cyclic light. Three ages were tested: 6-8, 13-15, and 21-24 dpf. The method used to assess retinal function was the electroretinogram (ERG). Comparisons were made across the three age groups and the three conditions. Differences in the ERG waveforms and spectral sensitivities across the three ages were found. The 6-8 and 13-15 dpf subjects were less sensitive than the 21-24 dpf group. Also, the 21-24 dpf had adult-like U- and S-cone function, but were missing the L-M and the M-S opponent mechanisms found in the adult. Deficits from the light rearing conditions were seen immediately following exposure (6-8 dpf). The LL condition subjects showed the greatest deficit in the ultraviolet and short-wavelength areas, and the DD condition subjects showed a slight deficit across the entire spectrum. At 13-15 dpf, the LL and DD groups showed an increase in sensitivity and by 21-24 dpf the differences that had been apparent were gone. The results of this study show that the zebrafish is a good model for vertebrate retinal development and function. Thus, the behavioral developmental trend that is seen in other vertebrates is also present in the zebrafish. In addition, the zebrafish is adversely affected by abnormal light rearing environments. The pattern of damage that was seen in primates appears to be present in the zebrafish. However, unlike the primates, the zebrafish appears to be capable of regeneration, thereby suggesting that the zebrafish would be a viable model for light environment effects and regeneration.
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Iconic Memory and Aging: Effects of Stimulus Duration, Stimulus Contrast, and Inter-Stimulus IntervalLaJoie, Andrew 01 May 1998 (has links)
Previous studies have shown that old adults perform more poorly on the classic Sperling partial report task than do young adults. In this study, the researcher examined whether age differences in performance could be accounted for by changes in visual and perceptual ability. Eighteen old adults (M = 70 years) and 18 young adults (M = 22 years) were administered whole and partial report trials with stimulus durations of 150 ms; a second group of 18 young adults was tested with stimulus durations of 30 ms. Stimuli were presented at two levels of contrast (98 and 44 percent) and the partial report trials included four cue-delay conditions (0, 50, 150, 300 ms). Measures of processing speed, visual acuity, contrast sensitivity and word fluency were collected as predictor variables. Old adults demonstrated partial report superiority at the 0 ms cue-delay, but fell to whole report levels at longer delays. Young participants demonstrated partial report superiority across all cue-delays, regardless of stimulus duration. Letter recall was not influenced by stimulus contrast. Predictor variables, except word fluency, accounted for approximately equal amounts of age-related variability. Results suggest that factors such as processing speed and visual ability, rather than changes in iconic memory, may be responsible for age differences in partial report performance.
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Exploration of the Relationship Between Moral Judgment Development and Crystallized IntelligenceJones, Kristy 01 August 2004 (has links)
Recent studies have reported different findings about how moral judgment as defined by the Defining Issues Test (DIT; Rest, Narvaez, Bebeau, & Thoma, 1999) relates to verbal intellectual ability. For example, Sanders, Lubinski, and Benbow (1995) argued that DIT scores are reducible to indices that represent verbal intellectual ability. Thoma and his colleagues (Derryberry, Thoma, Narvaez, & Rest, 2000; Thoma, Derryberry, & Narvaez, 2003; Thoma, Narvaez, Rest, & Derryberry, 1999) found support that DIT scores and indices of verbal intellectual ability are separate sources of information. In considering this relationship, these previous studies have most often referred to grade point average (GPA), American College Test (ACT), and Scholastic Aptitude Test (SAT) scores in describing verbal intellectual ability. As such, this research has been vague in defining what is meant by verbal intellectual ability. The present study recognizes Cattell and Horn's (1978) conception of crystallized intelligence as similar to the construct that the aforementioned research has considered. Therefore, the present study was designed to gain a better understanding about the nature of DIT scores in considering how they relate to an actual assessment of crystallized intelligence. For the current study, 117 participants provided complete data across two sessions. In the first session, participants were given the DIT and the Attitudes toward Human Rights Inventory (ATHRI; Getz, 1985). In the second session, participants were assessed using the Kaufman Adolescent and Adult Intelligence Test (KAIT; Kaufman & Kaufman, 1993). Results support the idea that DIT and KAIT scores are separate sources of information and influence ATHRI scores differently. Results also show that crystallized intelligence scores contribute to moral judgment scores though there is much variance that is unshared between these two constructs. Thus, the present study affirms the construct validity of the DIT but points to a role for crystallized intelligence in the measurement of moral judgment. Based on the evidence from the current study, there is evidence that upholds an important approach to measuring moral judgment development. Furthermore, there is little evidence supporting queries (e.g., Lykken, 1991) that have maintained that measurements of popular psychological constructs are the product of intellectual ability.
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The Perception and Recognition of 3-D Shape from Shadows Cast onto Curved SurfacesLee, Young-Lim 01 August 2003 (has links)
The informativeness of a cast shadow or silhouette boundary contour for the perception of 3-D object shape has been investigated for a long time. Some researchers have focused on the informativeness of static shadows (Attneave, 1954; Koenderink, 1984; Richards, Koenderink, & Hoffman, 1987; Norman, Phillips, & Ross, 2001; Tse, 2002) while other researchers have focused on the informativeness of moving or deforming shadows (Miles, 1931; Wallach, & O'Connell, 1953; Norman, & Todd, 1994; Norman, Dawson, & Raines, 2000; Norman, & Raines, 2002). Past research has shown that changing the angle of illumination does not affect the perception of 3-D shape from cast shadows (Norman et al., 2000). The current experiment extends the prior experiments by further investigating whether curved background surfaces (with both positive and negative Gaussian curvature) affect the perception and recognition of 3-D object shape from deforming and/or static cast shadows. In this experiment, the observers viewed either deforming or static shadows of naturally shaped objects (bell-peppers) cast onto either flat, hemispherical, or saddle-shaped surfaces. The results revealed significant main effects of motion (deforming vs. static shadows), object, and the type of background surface. The results revealed that there were also a number of significant interactions involving particular objects, the presence or absence of motion, and the type of background surface. The observers' ability to recognize objects from deforming shadows was higher than their ability to recognize objects from static shadows. In addition, the observers' ability to recognize objects from the shadows cast onto the hemisphere background surface was generally as accurate as their ability to recognize objects from the shadows cast onto the flat plane. However, the observers' ability to recognize the objects was reduced when the shadows were cast onto the saddle background surface. The results of the experiment confirm previous findings showing that shadow boundary contours, especially deforming contours, are perceptually informative and help observers to perceive and recognize 3-D object shape. This experiment also extends previous studies by showing how differently curved background surfaces affect the perception and recognition of 3-D object shape.
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The Role of Implicit Racial Attitudes and Universal Orientation in Cross-Racial Face RecognitionCampbell, Gordon 01 August 2002 (has links)
The "other-race" effect refers to the common observation that individuals are better at remembering faces of their own race than faces of another race. The relevance of the "other-race" effect to social interaction between people of different races and eyewitness identification of criminal suspects has spurred much research into uncovering the nature of the asymmetry between recognition of own- and otherrace faces. So far, however, many attempts to consistently demonstrate factors that contribute to the "other-race" effect have failed. One of the factors that may play a role in the "other-race" effect, but has yet to be shown to do so empirically, is racial attitudes. Past research attempting to link racial attitudes to cross-race face recognition has mainly used explicit measures of racial attitudes. The goal of the current study was to find out if explicit racial attitudes, implicit racial attitudes, and a personal social outlook of "inclusiveness" relate to the "other-race" effect. White participants completed explicit attitudes measures, a measure of "inclusiveness," the Bona Fide Pipeline procedure (Fazio, Jackson, Dunton, & Williams, 1995), and a short priming task designed to assess racial attitudes. Explicit racial attitudes were found to relate to the "other-race" effect in a nonlinear manner. Implicit racial attitudes measured by the Bona Fide pipeline did not relate to the "other-race" effect, but implicit racial attitudes measured by the short priming task related to cross-race face recognition in a linear manner. Scores from the measure of "inclusiveness" as a social outlook did not relate to the "other-race" effect. Implications for research on the "other-race" effect and the Bona Fide Pipeline procedure are discussed.
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The Effect of Cognitive Load on Illusory CorrelationSimpson, Jason 01 May 2002 (has links)
This study investigated two theories of illusory correlation in social judgment by examining how varying the level of cognitive load during encoding of social stimuli affected the amount of illusory correlation. If the level of illusory correlation increases in a monotonic relationship with increasing cognitive load, then this type of increase would provide evidence for the distinctiveness-based view of illusory correlation (Hamilton & GifFord, 1976); however, if levels of illusory correlation show a curvilinear relationship, this relationship would provide support for the differentiated meaning view (Haslam, McGarty, & Brown, 1996). Cognitive load was manipulated by having participants perform an auditory secondary task while stimuli were presented and the level of illusory correlation was examined after low, medium, and high levels of cognitive load. The findings failed to provide support for either the distinctiveness-based or the differentiated meaning view. However, there was some indication that more illusory correlation was present in the high cognitive load condition than in low load condition.
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The Effect of Age-Related Stereotypes on Memory Self-Efficacy and Memory Task-Performance of Older AdultsKarns, Brenda 01 May 2001 (has links)
Forty-six older adults participated in a study to examine the hypothesis that there is a significant association between stereotypes of age-related memory decline and memory self-efficacy beliefs. It was also hypothesized that this relationship affects performance on measures of memory performance. A measure of age stereotype vulnerability was assessed along with two measures of memory self-efficacy, four measures of implicit, explicit, and working memory, and two measures of implicit and explicit sequential learning. Structural equation modeling was used to analyze the relationships among stereotypes of age, memory self-efficacy, and subsequent performance on various tasks of memory and learning. Emphasis was placed on the memory self-efficacy construct as a moderating variable and its utility in examining cognitive behavior in adults. The model hypothesized for this research was not supported.
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