Modeling the role of parallel processing in visual search

Treisman's Feature Integration Theory and Julesz's Texton Theory explain many aspects of visual search. However, these theories require that parallel processing mechanisms not be used in many visual searches for which they would be useful, and they imply that visual processing should be much slower than it is. Most importantly, they cannot account for recent data showing that some subjects can perform some conjunction searches very efficiently. Feature Integration Theory can be modified so that it accounts for these data and helps to answer these questions. In this new theory, which we call Guided Search, the parallel stage guides the serial stage as it chooses display elements to process. A computer simulation of Guided Search produces the same general patterns as human subjects in a number of different types of visual search.     

Active engagement in a web-based tutorial to prevent obesity grounded in Fuzzy-Trace Theory predicts higher knowledge and gist comprehension

We used Sharable Knowledge Objects (SKOs) to create an Intelligent Tutoring System (ITS) grounded in Fuzzy-Trace Theory to teach women about obesity prevention: GistFit, getting the gist of healthy eating and exercise. The theory predicts that reliance on gist mental representations (as opposed to verbatim) is more effective in reducing health risks and improving decision making. Technical information was translated into decision-relevant gist representations and gist principles (i.e., healthy values). The SKO was hypothesized to facilitate extracting these gist representations and principles by engaging women in dialogue, “understanding” their responses, and replying appropriately to prompt additional engagement. Participants were randomly assigned to either the obesity prevention tutorial (GistFit) or a control tutorial containing different content using the same technology. Participants were administered assessments of knowledge about nutrition and exercise, gist comprehension, gist principles, behavioral intentions and self-reported behavior. An analysis of engagement in tutorial dialogues and responses to multiple-choice questions to check understanding throughout the tutorial revealed significant correlations between these conversations and scores on subsequent knowledge tests and gist comprehension. Knowledge and comprehension measures correlated with healthier behavior and greater intentions to perform healthy behavior. Differences between GistFit and control tutorials were greater for participants who engaged more fully. Thus, results are consistent with the hypothesis that active engagement with a new gist-based ITS, rather than a passive memorization of verbatim details, was associated with an array of known psychosocial mediators of preventive health decisions, such as knowledge acquisition, and gist comprehension.     

Why is visual search superior in autism spectrum disorder?

This study investigated the possibility that enhanced memory for rejected distractor locations underlies the superior visual search skills exhibited by individuals with autism spectrum disorder (ASD). We compared the performance of 21 children with ASD and 21 age‐ and IQ‐matched typically developing (TD) children in a standard static search task and a dynamic search task, in which targets and distractors randomly changed locations every 500 ms, precluding the use of memory in search. Children with ASD exhibited overall faster reaction time (RT) relative to TD children, and showed no disruption in search efficiency in the dynamic condition, discounting the possibility that memory for rejected distractors augments their visual search abilities. Analyses of RT x set size functions showed no group differences in slopes but lower intercepts for the ASD group in both static and dynamic search, suggesting that the ASD advantage derived from non‐search processes, such as an enhanced ability to discriminate between targets and distractors at the locus of attention. Eye‐movement analyses revealed that the ASD and TD groups were similar in the number and spatial distribution of fixations across the search array, but that fixation duration was significantly shorter among children with ASD. Lower intercepts in static search were related to increased symptom severity in children with ASD. In summary, ASD search superiority did not derive from differences in the manner in which individuals with ASD deployed their attention while searching, but from anomalously enhanced perception of stimulus features, which was in turn positively associated with autism symptom severity.     

Informing supervision practice through research: A narrative inquiry

Intention: This study focused on questions of whether and how clients benefit from supervision. As practitioner research, the study was intended to shape the researchers’ own supervision practice. Method: The qualitative approach was based on interviews with a small number of experienced practitioners about their supervision experiences. The findings are presented in the form of reflexive stories, told by each researcher. Findings: In these stories the researchers tell how engagement with experienced practitioners’ accounts of their past supervision shaped the hopes and intentions the researchers hold for their future supervision. Implications forpractice: The stories suggest there are therapeutic benefits in an ethic of transparency that provides for practices that overtly carry stories in both directions between counselling and supervision.     

Religious Fundamentalism as Schema: Influences on Memory for Religious Information

Those with differing levels of religious fundamentalism (RF) may be selective in their memory for religious information. In Study 1, participants read a text about money or sex, with a judgmental or not-judgmental message. Higher RF was associated with more accurate recall and fewer intrusions. In Study 2, participants high or low in RF read texts about sex. High-RF participants had more accurate recall and fewer intrusions. However, high-RF participants had more recognition false alarms to sentences that were not presented. High RF may aid memory for religious information, but also increase familiarity of related but not presented information. Exposure to not-judgmental messages decreased RF scores, suggesting that textual messages can impact responses to fundamentalism scales.     

Outcomes of Parent Education Programs Based on Reevaluation Counseling

We report two studies in which a parent education program based on Reevaluation Counseling was field-tested on mothers randomly assigned to treatment groups or equivalent, no-treatment comparison groups. The goal was to evaluate the program's viability, whether there were measurable effects, whether those effects were sustained over time, and whether the program was effective among diverse populations. The first study involved middle income, married mothers (n = 25) with at least one child younger than age five. Eleven members of the no-treatment group participated in the program three months later. Pretest, posttest, and follow-up measures included a parental attitude survey and a parenting stress index. The second study involved 18 black mothers with children enrolled in Head Start. Six members of the no-treatment group participated in the program two months later. Added to the pretest, posttest, and follow-up measures were a parent attitude research instrument and a parenting practices questionnaire. Results were replicated within and across studies. Significant effects suggest that the program can reduce parenting-related stress, improve parental attitudes, and encourage authoritative parenting practices, although some effects tend to diminish somewhat over time. The program appears viable with mothers of various social status groups.     

Preventing Depression Among Adolescent Girls: Pathways Toward Effective and Sustainable Programs

Up to 25% of adolescent girls experience an episode of major depression, at least twice the rate found with adolescent boys. In addition to reducing the suffering associated with depression, prevention efforts with this high-risk population have the potential to avert short- and long-term functional impairment, reduce the risk of associated mental and physical health problems, and provide mental health services to teens who may not otherwise receive help. The effectiveness of such programs depends upon the ability to reach at-risk girls and provide effective intervention, and to accomplish these goals in ways that are sustainable in community settings such as schools. This article discusses the advantages and drawbacks of several methods of delivering prevention programs for adolescent depression, and highlights strategies to enhance the effectiveness and sustainability of these programs. Lessons learned from the implementation of a universal prevention program for Grade 9 girls (Resourceful Adolescent Program-RAP; Shochet et al., 2001) are discussed, and practical recommendations are provided with regard to systems, program, implementation, and evaluation factors. Session-by-session details of RAP are highlighted, focusing on cognitive-behavioral and interpersonal therapy concepts and methods, adapted for use in a classroom setting.     

Tracking unique objects

Is content addressable in the representation that subserves performance in multiple-object-tracking (MOT) experiments? We devised an MOT variant that featured unique, nameable objects (cartoon animals) as stimuli. There were two possible response modes: standard, in which observers were asked to report the locations of all target items, and specific, in which observers had to report the location of a particular object (e.g., "Where is the zebra?"). A measure of capacity derived from accuracy allowed for comparisons of the results between conditions. We found that capacity in the specific condition (1.4 to 2.6 items across several experiments) was always reliably lower than capacity in the standard condition (2.3 to 3.4 items). Observers could locate specific objects, indicating a content-addressable representation. However, capacity differences between conditions, as well as differing responses to the experimental manipulations, suggest that there may be two separate systems involved in tracking, one carrying only positional information, and one carrying identity information as well.     

Contextual cuing by global features

In visual search tasks, attention can be guided to a target item--appearing amidst distractors--on the basis of simple features (e.g., finding the red letter among green). Chun and Jiang's (1998) contextual cuing effect shows that reaction times (RTs) are also speeded if the spatial configuration of items in a scene is repeated over time. In the present studies, we ask whether global properties of the scene can speed search (e.g., if the display is mostly red, then the target is at location X). In Experiment 1A, the overall background color of the display predicted the target location, and the predictive color could appear 0, 400, or 800 msec in advance of the search array. Mean RTs were faster in predictive than in nonpredictive conditions. However, there was little improvement in search slopes. The global color cue did not improve search efficiency. Experiments 1B-1F replicated this effect using different predictive properties (e.g., background orientation-texture and stimulus color). The results showed a strong RT effect of predictive background, but (at best) only a weak improvement in search efficiency. A strong improvement in efficiency was found, however, when the informative background was presented 1,500 msec prior to the onset of the search stimuli and when observers were given explicit instructions to use the cue (Experiment 2).     

Neuropsychological Performance in Gulf War Era Veterans: Motivational Factors and Effort

Assuming that the underlying etiology of unexplained health-related symptoms in returning Gulf War (GW) veterans is multifactorial, the possible role of feigning or exaggeration of symptoms is worth consideration as a contributing factor. The present study assessed the relationship between motivation to perform well during neuropsychological assessment and objective neuropsychological test performance. Motivation was measured as the score on a visual memory task (Test of Memory Malingering, TOMM) of low difficulty. Participants included 77 veterans from the cohorts of GW- (n = 58) and Germany-deployed (n = 19) GW-era veterans described in two other papers in this issue who were administered the TOMM. Most veterans earned perfect or near-perfect scores on the TOMM (48–50/50). Scores 47 were associated with lower scores on neuropsychological tasks assessing attention, executive functions, and memory. Variability in test performance within and between tasks measuring similar functions was also found in participants with lower TOMM scores.