The effects of cocaine on behavior maintained by timeout from avoidance.

Rats were trained on concurrent schedules under which responses on one lever postponed shock (avoidance) and responses on the other lever produced brief (2-min) periods of signaled timeout from avoidance. For 6 rats, timeout from avoidance was programmed on a variable-interval 45-s schedule that generally resulted in rates that were lower than those on the avoidance lever. For another 6 rats, timeout was arranged on a variable-ratio 15 schedule that produced higher baseline rates. Cocaine (3 to 40 mg/kg) produced large, dose-dependent increases in behavior maintained by timeout in both groups of rats. Avoidance responding was also generally increased by cocaine, but the increases were of lesser magnitude. Increases in response rates were seen across a broad range of doses on behavior maintained by either interval or ratio schedules, an outcome that was unexpected on the basis of most studies of cocaine on food-maintained behavior. These results were similar to those of previous studies of the effects of amphetamine on behavior maintained by timeout from avoidance and suggest that stimulant drugs affect behavior maintained under a shock-postponement schedule differently than they affect behavior maintained by timeout from avoidance.     

Physicians' values and physician-value neutrality

For years articles have decried the lack of empathy in physicians' relationships with patients. In addition to being empathetic, physicians are called upon to assume the posture of value neutrality, i.e., not imposing one's values when dealing with patients. Empathy is clearly an expression of deeply held values; even the language used to define it is value-laden. Physicians are consistently called upon to exhibit traits which are expressions of their underlying values. However, if proponents of value-neutrality are to be taken literally one must not impose any of one's values on one's patients. But then one wonders how empathy could ever be expressed; further, it is hard to imagine what a truly value neutral physician would be like. It is time we recognize that any relationship between two persons requires the expression of values from both parties. These values help shape that relationship and define its further history. Physicians are not excluded from this process just because they consider themselves professionals. Divulging personal values to patients is both more honest and more in keeping with the concepts of justice, beneficence, non maleficence, and autonomy than to feign value-neutrality. A presentation of some type statement of values is timely and would give patients an idea of where a physician stands on a myriad of issues. Rather than being value-neutral, value non-neutrality seems a more right and reasonable posture for physicians to assume.     

A behavioral assessment scale for attention deficit disorder in brazilian children based on DSM-IIIR criteria

A teacher scale based on DSM-III-R diagnostic criteria for attention deficit hyperactivity disorder (ADHD) was developed for the behavioral assessment of children in Brazil. A total of 2, 082 children (782 males and 1,300 females) with a mean age of 11.2 years who were attending a public school in the greater Rio de Janeiro area were the subjects of this study. Two factors (Hyperactivity-Impulsivity and Inattention) were extracted from a principal-factor analysis conducted on the data, and the factor structure of the scale was found to be stable. Ratings of boys were higher than ratings of girls, and younger children had higher ratings than older children for both factors. Test-retest reliability for each item of the scale ranged from .56 to .70. The data are discussed in view of current controversies in the factor structure of teacher ratings of DSM-III-R ADHD symptoms.This research was supported by FINEP (42.88.0138.00) and FUNPENE. GNOB is the recipient of a CNPq Research Career Development Award (30.0197/82). RCAP was supported by a CNPq fellowship (82.2151/87). The authors are grateful to Rosely V. Magalhaes and Angela S. Guedes for assistance in data analysis with the SAS and SPSS packages. The authors wish to thank the school staff and teachers who participated in the study. This work was presented at the Fifteenth European Conference of the International Neuropsychological Society, Portugal, 1993.     

Use of a computer-controlled firearms training simulator in perception response time experiments

This paper describes the use of a custom-configured computer-controlled firearms training simulator to measure perception response (reaction) time (RT) to a stimulus in which the degree of threat presented is a manipulable variable across trials. The computer records the number of frames of videotape traversed between the point of presentation of the threat in the video stimulus and the point at which the subject responds by drawing the firearm. For the purposes of data analysis, these frame-count measures are converted to RT measurements. Example data are presented that capture perception RT at both thedraw-stimulus and thefire-stimulus points in situations for which either only one threat or more than one threat exists. Other elements, such as degree of threat and accuracy of response, provide additional data.     

Mindless reading: Eye-movement characteristics are similar in scanning letter strings and reading texts

The purpose of the present study was to compare the oculomotor behavior of readers scanning meaningful and meaningless materials. Four conditions were used—a normal-text-reading control condition, and three experimental conditions in which the amount of linguistic processing was reduced, either by presenting the subjects with repeated letter strings or by asking the subjects to search for a target letter in texts or letter strings. The results show that global eye-movement characteristics (such as saccade size and fixation duration), as well as local characteristics (such as word-skipping rate, landing site, refixation probability, and refixation position), are very similar in the four conditions. The finding that the eyes are capable of generating an autonomous oculomotor scanning strategy in the absence of any linguistic information to process argues in favor of the idea that such predetermined oculomotor strategies might be an important determinant of eye movements in reading.     

Controlled attention sharing influences time estimation

A seminal attentional model of time estimation predicts that subjective duration will be positively correlated to the amount of attention given to temporal processing. This prediction holds under prospective conditions, in which one is forewarned that judgments of time will be asked, in contrast to retrospective conditions, in which such judgments are required after the relevant period without any prior warning. In three experiments, an attention-sharing method was used. Subjects were asked to control the amount of attention that they devoted to one or the other component of a dual-task paradigm. The first experiment involved word categorization and reproduction of duration. The following experiments, based on signal detection theory, required discrimination of both the duration and the intensity of a single stimulus, in the visual (Experiment 2) or the auditory (Experiment 3) modality. The results indicate that when the attention is directly controlled by the subject, the subjective duration shortens as the amount of attention devoted to the temporal task diminishes. The implications of these results for the possible existence of an internal timer are considered.     

Accreditation Standards for University and College Counseling Centers

The accreditation standards outlined in the article are used by the International Association of Counseling Services, Inc., as the basis for the formal accreditation of college and university counseling programs throughout the United States and Canada. They reflect the program elements and practice standards that are deemed essential in a counseling center that provides high-quality services to students.     

Visual slow brain potentials in children with attention deficit disorder

Using a two-stimulus reaction time paradigm, with two separate reward conditions (contingent and noncontingent), we compared slow wave brain potentials (ERPs) in 144 children with attention deficit disorder (ADD) and 30 normal control children. This article reviews the findings during the 900 msec visual warning stimulus. As we had expected, based on ERP work of Forth and Hare (1989) and Raine, Venables and Williams (1990), and on previous work from our own laboratory, the group differences were found in the negative slow wave portions of the ERP complex during the contingent reward condition but not during the noncontingent condition. Aggressive hyperactive subjects with attention deficit disorder (ADDHA) were discriminated from nonaggressive subjects (including control subjects) during the contingent reward condition in the following ways: (1) greater fronto-central negativity (640–900 msec slow wave) and (2) greater right parietal than left parietal negativity (430–750 msec slow wave). All ADD subgroups, when compared to control (CONTR) subjects, showed greater slow wave negativity (700–900 msec) at the midline occipital electrode site during the contingent reward condition. This could be explained in part as an IQ effect on ERPs reflecting the IQ difference between the ADD subgroups and the controls. These slow wave findings seem to relate to attentional problems of these children. They are discussed in terms of a psychobiological model of inhibition/disinhibition and appetitive activation.