Extraretinal and retinal amplitude and phase errors during Filehne illusion and path perception

Pursuit eye movements give rise to retinal motion. To judge stimulus motion relative to the head, the visual system must correct for the eye movement by using an extraretinal, eye-velocity signal. Such correction is important in a variety of motion estimation tasks including judgments of object motion relative to the head and judgments of self-motion direction from optic flow. The Filehne illusion (where a stationary object appears to move opposite to the pursuit) results from a mismatch between retinal and extraretinal speed estimates. A mismatch in timing could also exist. Speed and timing errors were investigated using sinusoidal pursuit eye movements. We describe a new illusion--the slalom illusion--in which the perceived direction of self-motion oscillates left and right when the eyes move sinusoidally. A linear model is presented that determines the gain ratio and phase difference of extraretinal and retinal signals accompanying the Filehne and slalom illusions. The speed mismatch and timing differences were measured in the Filehne and self-motion situations using a motion-nulling procedure. Timing errors were very small for the Filehne and slalom illusions. However, the ratios of extraretinal to retinal gain were consistently less than 1, so both illusions are the consequence of a mismatch between estimates of retinal and extraretinal speed. The relevance of the results for recovering the direction of self-motion during pursuit eye movements is discussed.     

Effects of Stimulant Medication Treatment on Mothers' and Children's Attributions for the Behavior of Children with Attention Deficit Hyperactivity Disorder

Participants were 55 children with attention deficit hyperactivity disorder (ADHD) who were receiving ongoing treatment with stimulant medications and their mothers, and 31 children with ADHD who were beginning stimulant medication and their mothers. Mothers and children offered attributions for child behaviors that occurred when the child was medicated and not medicated. Mothers rated child compliance and prosocial behavior as more global and stable when the child was medicated and rated noncompliance, ADHD symptoms, and oppositional behavior as more externally caused, less global and stable, but more controllable by the child when the child was medicated. Children rated both their compliance and noncompliance as more controllable in the medicated condition. On a forced-choice measure, both mothers and children selected ability, effort, and task attributions for compliance more in the not-medicated condition, and pill-taking attributions more in the medicated condition. This was reversed for noncompliance, which was attributed more to effort, task, or ability in the medicated condition and more to not taking a pill in the not-medicated condition. The potential risks and benefits for parent–child interactions and children's self-perceptions of these medication-related differences in attributions are discussed.     

Levels-of-processing effects on Chinese character completion: The importance of lexical processing and test cue

The levels of processing (LoP) effect was studied in Chinese character completion tasks. The same stem cue, either graphemically or semantically related to the target character, was used to generate either a perceptual or a conceptual test. Participants received either direct or indirect instructions, so that the same stem cue also produced either an explicit or an implicit test of memory. This allowed us to examine simultaneously the roles of perceptual versus conceptual test and retrieval intentionality in the LoP effect. No LoP effects were found when the memory test was implicit. LoP effects were also not found for stems and characters related graphemically (perceptually), but were found for stems and characters related semantically (conceptually) when the memory test was explicit. The results are discussed in terms of the importance of lexical processing for character completion tests and the importance of reinstatement of the study process during retrieval for explicit memory tests.     

Positive behavior support: Expanding the application of applied behavior analysis

Positive behavior support (PBS) is an approach to providing services to individuals who exhibit challenging behavior. Since its inception in the early 1990s, PBS has received increasing attention from the behavior-analytic community. Some behavior analysts have embraced this approach, but others have voiced questions and concerns. In this paper we describe the framework of PBS and show that it is consistent with the tenets of behavior analysis. Also, we illustrate how the framework of PBS might be used to guide practitioners and researchers in the field of applied behavior analysis. We hope to demonstrate that PBS offers useful suggestions regarding how applied behavior analysts can design and evaluate effective programs for people with developmental disabilities or behavioral challenges.     

The Factor Structure of the Beavers Interactional Scales

Confirmatory factor analysis and regression analyses of the Beavers Interactional Scales did not appear to support the model offered by its developers, namely, several specified family attributes contributing respectively to two global factors of Family Competence and Family Style. Moreover, regression analysis indicated that only three of 12 items predicted raters' assessments of Global Family Health, and one of seven items predicted Global Family Style. Individuals interested in the family dynamic centripetal/centrifugal might best think of that as a unitary entity and rate it accordingly.     

Efficiency of multiple-choice tests as a function of spread of item difficulties

The validity of a univocal multiple-choice test is determined for varying distributions of item difficulty and varying degrees of item precision. Validity is a function of _d ² + _v ² , where _d measures item unreliability and _v measures the spread of item difficulties. When this variance is very small, validity is high for one optimum cutting score, but the test gives relatively little valid information for other cutting scores. As this variance increases, eta increases up to a certain point, and then begins to decrease. Screening validity at the optimum cutting score declines as this variance increases, but the test becomes much more flexible, maintaining the same validity for a wide range of cutting scores. For items of the type ordinarily used in psychological tests, the test with uniform item difficulty gives greater over-all validity, and superior validity for most cutting scores, compared to a test with a range of item difficulties. When a multiple-choice test is intended to reject the poorestF per cent of the men tested, items should on the average be located at or above the threshold for men whose true ability is at theFth percentile.This research was performed under contract Nop 536 with the Bureau of Naval Personnel, and received additional support from the Bureau of Research and Service, College of Education, University of Illinois.     

Personality Traits Beyond the Big Five: Are They Within the HEXACO Space?

Paunonen (2002) recently developed the Supernumerary Personality Inventory (SPI), a measure of 10 traits that have low loadings within the space of the Big Five personality factors. If the SPI personality traits are representative of the domain of non-Big Five personality traits, then the major source of the variance in the SPI traits would be expected to correlate strongly with the sixth factor of personality, Honesty-Humility. We tested this hypothesis using self-report measures (N = 200) of the SPI traits, of the Big Five, and of the new six-dimensional ("HEXACO") structure. Results indicated that the first unrotated factor underlying the 10 SPI traits was heavily saturated with variance from Honesty-Humility (r = .65). Nevertheless, the 10 SPI traits contained substantial amounts of unique variance not accounted for by the HEXACO or the Big Five variables, highlighting the importance of the facet-level assessment of personality traits.     

Individuality and social influence in groups: inductive and deductive routes to group identity

A distinction between forms of social identity formation in small interactive groups is investigated. In groups in which a common identity is available or given, norms for individual behavior may be deduced from group properties (deductive identity). In groups in which interpersonal relations are central, a group identity may also be induced from individual group members' contributions, making individuality and individual distinctiveness a defining feature of the group (inductive identity). Two studies examined the prediction that depersonalization produced by anonymity has opposite effects for groups in which social identity has been induced or deduced. Results confirmed the prediction that depersonalization increases social influence in groups whose identity was more deductive. In contrast, depersonalization decreases social influence in inductive identity groups. Implications for the role of social identity in small groups are discussed. ((c) 2005 APA, all rights reserved).     

Ergonomic comparison of operating a built-in touch-pad pointing device and a trackball mouse on posture and muscle activity

This study examined the effects of operating a built-in touch-pad pointing device and a trackball mouse on participants' completion times, hand positions during operation, postural angles, and muscle activities. 8 young men were asked to perform a cursor travel task on a notebook computer using both 60- and 80-cm high table conditions. Analysis showed that the trackball mouse significantly decreased completion times. Participants selected a hand position farther from the table edge and larger elbow angle for the trackball mouse than for the built-in touch-pad pointing device. Participants' neck, thoracic, and arm angles, or splenius capitis, trapezius, deltoid, and erector spinae muscle activities were not significantly affected by the devices, but table height significantly affected participants' completion times, hand positions, and postural angles.