The role of attention in motion extrapolation: are moving objects 'corrected' or flashed objects attentionally delayed?

Objects flashed in alignment with moving objects appear to lag behind [Nijhawan, 1994 Nature (London) 370 256-257]. Could this 'flash-lag' effect be due to attentional delays in bringing flashed items to perceptual awareness [Titchener, 1908/1973 Lectures on the Elementary Psychology of Feeling and Attention first published 1908 (New York: Macmillan); reprinted 1973 (New York: Arno Press)]? We overtly manipulated attentional allocation in three experiments to address the following questions: Is the flash-lag effect affected when attention is (a) focused on a single event in the presence of multiple events, (b) distributed over multiple events, and (c) diverted from the flashed object? To address the first two questions, five rings, moving along a circular path, were presented while observers attentively tracked one or multiple rings under four conditions: the ring in which the disk was flashed was (i) known or (ii) unknown (randomly selected from the set of five); location of the flashed disk was (i) known or (ii) unknown (randomly selected from ten locations). The third question was investigated by using two moving objects in a cost-benefit cueing paradigm. An arrow cued, with 70% or 80% validity, the position of the flashed object. Observers performed two tasks: (a) reacted as quickly as possible to flash onset; (b) reported the flash-lag effect. We obtained a significant and unaltered flash-lag effect under all the attentional conditions we employed. Furthermore, though reaction times were significantly shorter for validly cued flashes, the flash-lag effect remained uninfluenced by cue validity, indicating that quicker responses to validly cued locations may be due to the shortening of post-perceptual delays in motor responses rather than the perceptual facilitation. We conclude that the computations that give rise to the flash-lag effect are independent of attentional deployment.     

Task demands and limb apraxia in stroke

The present study was designed to examine the frequency and severity of apraxia in patients with left- or right-hemisphere stroke in both pantomime and imitation conditions and to compare the frequency of apraxia in each stroke group across the three patterns of apraxia described in Roy's model (Roy, 1996). Ninety-nine stroke patients and 15 age-matched healthy adults performed eight transitive gestures to pantomime and to imitation. Gestural performance was quantified as accuracy on five performance dimensions; a composite score, an arithmetic combination of the five performance dimensions, was used as an index of the overall accuracy. Analyses revealed a comparable proportion of patients in each stroke group were classified as apraxic in the imitation condition, but a higher proportion of left stroke patients were apraxic in the pantomime condition. The severity of apraxia in each stroke group and the performance dimensions affected were, however, comparable. Analyses of the patterns of apraxia (pantomime alone, imitation alone or apraxia in both conditions) revealed a higher frequency of apraxia in both stroke groups for the pattern reflecting apraxia in both conditions, indicating that a disruption at the movement execution stage of gesture performance was most common.     

Fifty Years of Prison Suicide in Austria: Does Legislation Have an Impact?

The absolute and relative frequency of suicides in jails and prisons in Austria over the 50 years from 1947 to 1996 is described. Important legislational changes regarding the criminal justice system are discussed with regard to possible consequences for the incidence of prisoners' suicides. Within the five decades a significant increase in the absolute numbers of jail and prison suicides was evident in spite of the considerable decrease in the total inmate population. Therefore, the suicide rate of inmates of correctional facilities increased significantly. Possible reasons for this phenomenon are discussed in relation to changes of the criminal law.     

Childhood Gender Nonconformity and Body Dissatisfaction in Gay and Heterosexual Men

Although researchers have long hypothesized a relation between gender role orientation (i.e., masculinity and femininity) and body dissatisfaction, findings have been inconsistent. The current study employed a measure of recalled childhood gender nonconformity to examine gender role behaviors in association with body dissatisfaction among an ethnically diverse (76% Caucasian, 2% African American, 8% Asian, and 16.4% Hispanic American) group of predominantly college-aged males of both homosexual (n = 129) and heterosexual (n = 52) orientation. Consistent with past research, gay males reported more body dissatisfaction and recalled more childhood gender atypical behaviors (e.g., disliking athletics, playing with dolls). Group differences in body dissatisfaction, however, disappeared when childhood gender nonconformity was statistically controlled, suggesting childhood atypical gender role behavior may place males at greater risk for adult body dissatisfaction. A within-group analysis also found that a high feminine subtype of gay males had greater body dissatisfaction than less feminine subtypes had. Results support the assertion that gender role behaviors may contribute to body dissatisfaction among gay males.     

Gender bias in self-report personality disorder inventories

There has been considerable controversy and research regarding gender biases in the diagnosis of personality disorders, but few studies have explored whether personality disorder self-report inventories might contain gender biases. The current study investigated whether items from three commonly used inventories evidence a potential for gender bias. Subjects were from outpatient mental health clinics. Items were considered gender biased if they exhibited gender differences and failed to correlate with or, more importantly, correlated negatively with dysfunction. Thirty-eight items evidenced potential bias, the majority of which were from Narcissistic scales. The implications of the results for the clinical assessment of purportedly maladaptive personality traits and for the construction of personality disorder scales are discussed.     

Low-frequency acoustic modulations generated by the high-frequency portion of the cochlea, noninvasively recorded from the scalp of mice (Mus musculus)

Vocalizations often contain low-frequency modulations of the envelope of a high-frequency sound. The high-frequency portion of the cochlear nerve of mice (Mus musculus) generates a robust phase-locked response to these low-frequency modulations, and it can be easily recorded from the surface of the scalp. The cochlea is most sensitive to envelope modulation frequencies of approximately 500 to 2000 Hz. These responses have detection thresholds that are approximately 10 dB more sensitive than auditory brainstem responses, and they are very sharply tuned. These measurements may provide a nontraumatic means of repeatedly assessing cochlear functions involved in sound localization and perception of vocalizations.     

Numerical competence in rats (Rattus norvegicus): Davis and Bradford (1986) extended

The task of rats (Rattus norvegicus) was to enter 1 box of a defined ordinal number among an array of boxes. In Experiments 1 and 2, the rats correctly chose the 4th box from arrays of 6 and 12 boxes, respectively. In Experiments 3 and 4, in which the ordinal number of the correct box was increased in a graduated fashion, they were able to select the correct box even when its position was higher than 10th among 12 and 18 boxes, respectively. In Experiment 5, the possibility that the rats had used cues to the openability of the box doors was ruled out. In Experiments 6 and 7, the rats succeeded in the task even when the total number of boxes was varied from trial to trial. In Experiment 8, both small- and large-sized boxes were used to control for the possibility of using the cumulative length of the boxes as a cue. Overall, the results suggest that performance was based on numerical cues. Intentional acts were occasionally observed but appeared not to be essential for solving the task.     

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.