Integration of visual and vestibulo-tactile inputs affecting apparent self-motion around the line of sight

We investigated the effects of visual and vestibulo-tactile inputs on perceived self-motion. Each of 23 subjects was exposed to an optical pattern rotating around the roll axis (i.e., line of sight) while the chair, in which the subject was placed, was rotated back and forth between +/-70 degrees (i.e., large rolling) or between +/-35 degrees (i.e., small rolling) from the gravitational vertical. Each subject judged perceived velocity of self-motion under each of 16 combinations of pattern velocity and chair velocity. The main results were the following: (1) The mean estimation increased with pattern velocity, and it also increased with chair velocity, (2) to attain a constant perceived velocity of self-motion, pattern velocity was traded for chair velocity, and for the large rolling of the chair, visual inputs were more effective than vestibulo-tactile inputs, whereas for the small rolling, the inverse was true; (3) analyses of multiple regression, when applied to the mean estimations, showed that for both rollings of the chair, the visual component dominated over the vestibulo-tactile component, but for the small rolling of the chair, the difference in effectiveness between the two components was attenuated. We discuss these findings in terms of visual-vestibular interaction.     

Relationship between stages of smoking acquisition and environmental factors among junior high school students

To study the relationship of stages of smoking acquisition and environmental factors, 757 Japanese junior high school students (390 boys and 367 girls) anonymously answered a questionnaire regarding the four stages of smoking acquisition (precontemplation, contemplation, preparation, and action stages) and environmental factors of smoking behavior. Analysis showed that the influence of advertising and students' interpersonal situations on smoking behavior increased from the precontemplation stage to the action stage.     

Integration and representation in rats' serial pattern learning in the T-maze

Rats were exposed to three-trial series consisting of reinforced (R) trials and one nonreinforced (N) trial in a fixed order, RRN and RNR (Experiments 1 and 2) or NRR and RRN (Experiment 3), on extended visually distinct runways in a T-maze. When initially presented with the same sequence on each series in a session (separate presentations) with the same runway on all trials within a series (Experiments 1 and 3), all the rats developed slower running speeds on N than on R trials. When a runway was sometimes changed between the first and next two trials during separate presentations training (Experiment 2) or both sequences were later intermixed within each session in each experiment, only rats exposed to each sequence on a specific runway maintained these serial running patterns. Rats displayed serial running patterns on a test RNN sequence similar to that on the RNR sequence (Experiment 2), as would be predicted by an intertrial association model of serial pattern learning (Capaldi & Molina, 1979), but responded on test RRR and NRN sequences (Experiment 3) as would be predicted by an ordinal-trial-tag/intratrial association model (Burns, Wiley, & Payne, 1986). Results from test series of free-choice trials in Experiments 1 and 2 failed to support a prediction of the intratrial association model that these rats would integrate RRN and RNR sequences. Rather than always selecting a baited runway on both the second and the third free-choice trials, the rats only selected a baited runway on the third trial on the basis of their choice on the second trial, as would be predicted by the intertrial association model. Only after experiencing all possible outcome sequences during forced-choice training in Experiment 3 did these rats predominantly select a baited runway on every free-choice trial.     

A feature-segmentation model of short-term visual memory

A feature-segmentation model of short-term visual memory (STVM) for contours is proposed. Memory of the First stimulus is maintained until the second stimulus is observed. Three processes interact to determine the relationship between stimulus and response: feature encoding, memory, and decision. Basic assumptions of the model are twofold: (i) the STVM system divides a contour into convex parts at regions of concavity; and (ii) the value of each convex part represented in STVM is an independent Gaussian random variable. Simulation showed that the five-parameter fits give a good account of the effects of the four experimental variables. The model provides evidence that: (i) contours are successfully encoded within 0.5 s exposure, regardless of pattern complexity; (ii) memory noise increases as a linear function of retention interval; (iii) the capacity of STVM, defined by pattern complexity (the degree that a pattern can be handled for several seconds with little loss), is about 4 convex parts; and (iv) the confusability contributing to the decision process is a primary factor in deteriorating recognition of complex figures. It is concluded that visually presented patterns can be retained in STVM with considerable precision for prolonged periods of time, though some loss of precision is inevitable.     

Visual feature binding in early infancy

How does the developing brain of the human infant solve the feature-binding problem when visual stimuli consisting of multiple colored objects are presented? A habituation--dishabituation procedure revealed that 1-month-old infants have the ability to discriminate changes in the conjunction of a familiar shape and color in two objects. However, this good earlier performance was followed by poorer performance at 2 months of age. The performance improved again at 3 months of age. Detailed analysis of the oculomotor behaviors revealed that the age of 2 months was a period of drastic transition when the tendency to stay with the fixated objects disappeared and repetitive saccades between the two objects emerged. Our findings suggest that the ability to perceive conjunctions of features is available to infants very early, that the perceptual/neural basis at 1 and at 3 months of age may be fundamentally different, and that feature integration by vigorous eye movements or selective attention may be the key functional difference between the age groups.     

Employment of persons with disabilities in information technology jobs: literature review for "IT works"

This article reviews relevant literature as to the labor pool of qualified individuals with disabilities and employment in information technology (IT) sector jobs. First, the article reviews the empirical literature on barriers to employment in IT for persons with disabilities. The examination then is extended to studies of barriers to employment for individuals with disabilities in other employment sectors. Findings illustrate the limited experiences that IT and non-IT companies have in employing and accommodating employees with disabilities. Implications are discussed for enhancing the employment of qualified workers with disabilities in IT through research, education, training, and mentoring programs.     

Attending to the big picture: mood and global versus local processing of visual information

Two experiments employed image-based tasks to test the hypothesis that happier moods promote a greater focus on the forest and sadder moods a greater focus on the trees. The hypothesis was based on the idea that in task situations, affective cues may be experienced as task-relevant information, which then influences global versus local attention. Using a serial-reproduction paradigm, Experiment 1 showed that individuals in sad moods were less likely than those in happier moods to use an accessible global concept to guide attempts to reproduce a drawing from memory. Experiment 2 investigated the same hypothesis by assessing the use of global and local attributes to classify geometric figures. As predicted, individuals in sad moods were less likely than those in happier moods to classify figures on the basis of global features.     

A crossmodal attentional blink between vision and touch

There is currently a great deal of interest regarding the possible existence of a crossmodal attentional blink (AB) between audition and vision. The majority of evidence now suggests that no such crossmodal deficit exists unless a task switch is introduced. We report two experiments designed to investigate the existence of a crossmodal AB between vision and touch. Two masked targets were presented successively at variable interstimulus intervals. Participants had to respond either to both targets (experimental condition) or to just the second target (control condition). In Experiment 1, the order of target modality was blocked, and an AB was demonstrated when visual targets preceded tactile targets, but not when tactile targets preceded visual targets. In Experiment 2, target modality was mixed randomly, and a significant crossmodal AB was demonstrated in both directions between vision and touch. The contrast between our visuotactile results and those of previous audiovisual studies is discussed, as are the implications for current theories of the AB.     

Windowed cross-correlation and peak picking for the analysis of variability in the association between behavioral time series

Cross-correlation and most other longitudinal analyses assume that the association between 2 variables is stationary. Thus, a sample of occasions of measurement is expected to be representative of the association between variables regardless of the time of onset or number of occasions in the sample. The authors propose a method to analyze the association between 2 variables when the assumption of stationarity may not be warranted. The method results in estimates of both the strength of peak association and the time lag when the peak association occurred for a range of starting values of elapsed time from the beginning of an experiment.     

Hotep's Story: Exploring the Wounds of Health Vulnerability in the US

A wide variety of forms of domination hasresulted in a highly heterogeneous health riskcategory, ``the vulnerable.' The study of healthinequities sheds light on forces thatgenerate, sustain, and alter vulnerabilities toillness, injury, suffering and death. Thispaper analyzes the case of a high-risk teenfrom a Boston ghetto that illuminatesintersections between ``race' and class in theconstruction of vulnerability in the US.Exploration of his ``wounds' helps specify howlarge-scale social and cultural forces becomeembodied as individual experience of disparatehealth risk. The case demonstrates that healthinequities would not occur if resources –employment, income, wealth, education, housing,profiling in the legal system, and health care– were more justly managed in keeping withstandards outlined in the Universal Declarationof Human Rights. Professional responses to the``wounds of vulnerability' may reveal importantaspects of who we are and what our work asscholars, practitioners, and advocates mustbecome.