Spatiotemporal boundaries of linear vection

Thresholds for the perception of linear vection were measured. These thresholds allowed us to define the spatiotemporal contrast surface sensitivity and the spatiotemporal domain of the perception of rectilinear vection (a visually induced self-motion in a straight line). Moreover, a Weber’s law was found, such that a mean relative differential threshold in angular velocity of about 41% is necessary to perceive curvilinear vection. This visually induced self-motion corresponds to the sensation of moving in a curved path. It is proposed that curvilinear vection is induced when the apparent velocity difference is detectable. The spatiotemporal domain of perception of rectilinear vection and its spatiotemporal contrast surface sensitivity are centered on low spatial frequencies. Concurrently, the values which correspond to the relative differential thresholds of curvilinear vection are low spatial frequencies. Accordingly, the peripheral ambient visual system seems to be involved in perceiving linear vection. It is argued further that the central ambient system might also be involved in the processing of linear vection.     

Role of the striatal cholinergic system in the regulation of learned manipulation in rats

The experiments were performed on adult Wistar male rats trained to push with the forepaw on a fixed piston inside a narrow tube. It was found that after localized intracerebral injection of a cholinergic antagonist into the dorso-lateral (but not medial) neostriatum (i.e., the caudato-putamen) the behavioral performance requiring brief innate movements remained unchanged, but the performance requiring a prolonged pushing movement (> 50 msec) became disrupted. Microinjection of carbacholine (0.03-3 μ g/1 μ1) did not affect the performance of the acquired movements, whereas scopolamine (3 μ g/1 μ1) led to the significant decrease in pushing time. We conclude that changes in the state of the dorso-lateral neostriatal cholinergic system result only in disturbances of the sensory-controlled component of a complex instrumental movement. The 1994 Pavlovian Society Young Investigator Awardee was Nadezda Dubrovskaya, first author of this paper, which was presented at the annual meeting of the Pavlovian Society, July 3, 1994, in Prague, Czech Republic.     

A pointing technique for rapidly collecting localization responses in auditory research

A technique is described for rapidly collecting responses in auditory-localization experiments. Subjects indicate the perceived direction of the sound by pointing at a 20-cm-diam spherical model. In Experiment 1, the subjects judged the direction of a broadband signal, which could originate from any of 239 directions ranging through 360° of azimuth and between ?45° and +90° of elevation. Using this technique, the subjects responded 2–8 times more rapidly than previous subjects who used either a verbal-reporting technique or a head-pointing technique. Localization judgments were as accurate as they had been with verbal reports, but were not as accurate as judgments collected using the head-pointing technique. In Experiment 2, the signal was turned off and the experimenter read the spherical coordinates of the signal location to the subjects. The subjects pointed to these coordinates more accurately than they had judged the direction of the sounds in Experiment 1, suggesting that the response technique had not been the limiting factor in that experiment. Circumstances relevant to the choice of response techniques for auditory-localization experiments are discussed.     

The Fire Chief microworld generating program: An illustration of computer-simulated microworlds as an experimental paradigm for studying complex decision-making behavior

Computer-simulated microworlds bridge the gap between the complexity of field investigations and the rigor of laboratory studies. The purpose of this paper is to draw attention to the major methodological issues involved in developing and using computer-simulated microworlds for the psychological study of complex decision-making behavior. These issues comprise flexibility and generality in the microworlds that can be created, adequate psychological validity, automatic trial administration and data logging, capacity to interface simulations of psychological processes, and adequate testing and documentation. Each of these issues is illustrated by indicating how it has been addressed in Fire Chief, a microworld generating program specifically designed for creating realistic, yet controllable, decision-making task environments in the psychology laboratory. Fire Chief (Omodei & Wearing, 1993a) is introduced as both fully portable to other research teams and suitable for use in many different contexts requiring a complex task situation.     

Prenatal gender preference of mothers of feminine and masculine boys: Relation to sibling sex composition and birth order

A mother's (prenatal) wish for a girl has, at times, been implicated as an etiological factor for boyhood femininity or its DSM-III-R diagnostic equivalent, the Gender Identity Disorder of Childhood. In one sample of 52 feminine and 52 nonclinical control boys from Los Angeles, the proportion of mothers who recalled a wish for a girl during the pregnancy did not differ significantly between groups (26.9% vs. 19.2%, respectively); however, in both groups, the maternal wish for a girl was significantly more common in sibships in which all of the proband's older siblings were male. In a second sample of 103 feminine boys from Toronto, the maternal wish for a girl was significantly higher than that found in the Los Angeles sample (43.7% vs. 26.9%), but a control group was not available; as in the Los Angeles sample, the maternal wish for a girl was significantly more common in sibships in which all of the proband's older siblings were male. Implications of these findings for further study of maternal influences on boyhood femininity are discussed.     

An advocacy intervention program for women with abusive partners: Six-month follow-up

Presented the 6-month follow-up findings of an experimental intervention designed to provide postshelter advocacy services to women with abusive partners. The intervention involved randomly assigning half the research participants to receive the free services of an advocate, 4 to 6 hours per week, for the first 10 weeks postshelter. One hundred forty-one battered women were interviewed about their experiences immediately upon their exit from a domestic violence shelter: 95% of the sample were interviewed 10 weeks thereafter (postintervention), and 93% were successfully tracked and interviewed 6 months later. At the 6-month follow-up, participants in both groups reported increased social support, increased quality of life, less depression, less emotional attachment to their assailants, and an increased sense of personal power. Although women in both groups reported some decrease in physical abuse over time, there were no statistically significant differences between those with and those without advocates, and abuse continued to be a problem for many women. Those who were still involved with their assailants continued to experience higher levels of abuse and had been more economically dependent upon the men prior to entering the shelter. Women who had worked with advocates continued to report being more satisfied with their overall quality of life than did the women in the control group. The authors thank the Editor and anonymous reviewers for their helpful comments. Thanks also to all present and past staff of the Community Advocacy Project, who helped in data collection and analyses. This work was supported by National Institute of Mental Health Grant 1R01 MH 44849.     

Discrimination of Facial Identity and Facial Affect by Temporal and Frontal Lobectomy Patients

The purpose of this study was to determine the extent to which lobectomy affects ability to discriminate facial identity or facial expression. Fifteen right temporal, 15 left temporal, 5 right frontal, and 4 left frontal lobectomy patients, pair-matched for age, sex, and education to normal control subjects, participated in this study. Tasks included a Facial Identity Matching Task and a Facial Affect Matching task. The lobectomized patients as a whole were significantly impaired on both tasks (22% decrement in performance). The patients made twice as many errors resulting from perseveration of response-set of the first condition (identity or emotion matching) into the second condition. The site of lobectomy did not influence general performance on any one task or selective performance on any subset of affective categories. It was concluded that all four brain regions play a significant and equal role in face processing, and that circuits more specifically dedicated to visual face processing, which are responsible for hemispheric dominance affects and affect/identity dissociations, are probably located more posteriorly in the brain. Finally, it was concluded that perseveration of acquired habit may, under specific conditions, characterize temporal lobe dysfunction just as much as frontal lobe dysfunction.