Discriminability between alternatives in a switching-key concurrent schedule

Six pigeons were trained to discriminate between two intensities of white light in a symbolic matching-to-sample procedure. These stimuli were then used to signal which schedule was available on the main key in a switching-key concurrent schedule. The concurrent schedules led to a symbolic matching-to-sample phase in which the subject identified the concurrent schedule to which it last responded before a reinforcer could be obtained. The concurrent schedules were varied across conditions. Discriminability, measured during the symbolic matching-to-sample performance, was high throughout and did not differ across the two procedures. Performance in the concurrent schedules was like that typically obtained using these schedules. Delays were then arranged between completion of the concurrent schedules and presentations of the symbolic matching-to-sample phase. A series of conditions with an intervening delay of 10 s showed that both concurrent-schedule performance and symbolic matching-to-sample performance were affected by the delay in a similar way; that is, choice responding was closer to indifference.     

Effects of reinforcer delays on choice as a function of income level

Three rats earned their daily food ration by responding during individual trials either on a lever that delivered one food pellet immediately or on a second lever that delivered three pellets after a delay that was continuously adjusted to ensure substantial responding to both alternatives. Choice of the delayed reinforcer increased when the number of trials per session was reduced. This result suggests that models seeking closure on choice effects must include a parameter reflecting how preference changes with sessionwide income. Moreover, models positing that reinforcer probability and immediacy (1/delay) function equivalently in choice are called into question by the finding that probability and immediacy produce opposing effects when income level is changed.     

Time-place learning by pigeons, Columba livia

In each of two experiments, 2 pigeons received discrimination training in which food reinforcement for key pecking was conditional upon both spatial and temporal cues. In Experiment 1, food was available for periods of 30 s at each of three locations (pecking keys) during trials that lasted 90 s. In Experiment 2, food was available for periods of 15 min at each of four locations (pecking keys) during a 60-min trial. In both experiments, pigeons' key pecking was jointly controlled by the spatial and temporal cues. These data, and other recent experiments, suggest that animals learn relationships between temporal and spatial cues that predict stable patterns of food availability.     

The relationship between research and design of AIDS prevention program

The global threat of AIDS requires massive public educational campaigns that employ social and behavioral sciences such as psychology, sociology, and anthropology because sexual behavior possesses a social dimension. Research is concerned with what stimulates behavioral change, what are the prerequisites of learned behavior, and what enables personal control over the environment and future. Educational programs designing strategies for AIDS prevention require social and behavioral science content and input. Interdisciplinary provides general principles with psychological, social, and cultural aspects of human behavior. Without knowledge about psychological processes (thinking, perception, speech, aspects of personality, and interactive behavior) and social processes (economic conditions, social networks, and resources) which are implicated in health problems and also in AIDS, these educational programs cannot produce credible results. These programs and their subsequent implementation require their application in practice in a systemic and consistent fashion. Evaluations are also needed to make sure that the applied processes for behavioral change conform to methodological criteria that ensure their effectiveness. These types of studies are more complex than pure AIDS research which is aimed at finding a cure.     

Design and implementation of a program for AIDS prevention in female prostitutes

The Companeros model of HIV infection prevention in Ciudad Juarez, Mexico, is presented as conceived by the National Institute of Drug Abuse (NIDA). 518 women who were IV drug users, sexual partners of drug addicts, or prostitutes were requested to participate, and 232 consented. Initial and follow-up AIDS assessments were utilized along with an assessment of sociodemographic variables, including knowledge, sexual behavior, use and abuse of drugs, and previous health history. Educative sessions about AIDs and sexually transmitted diseases (STDs) included group discussions and interaction, video watching, personal experiences, and sociodramas. 61% of prostitutes were 29, 12.6% were 13-19 years old, 31.1% were aged 30-39, and 8.9% were 40. 11% had no formal education, 58% had 6 years of primary and part of 3 years of secondary education, only 18.6% completed secondary education; and 13% had higher education. 19% lived in a hotel or shelter. Family disintegration reached 44%; these women did not live with their children. Only 5.2% thought they had excellent health, 51% said they had good health, 31% stated they had average health, and 12% admitted having had health problems. 14.6% had genital ulcers, 1.3% had herpes, 15% had gonorrhea, and 10% had syphilis. Since IV drug use among these women was almost nonexistent sexual relations constituted the principal risk factor. Responses to a questionnaire showed that the most frequent sexual behavior was vaginal penetration followed by fellatio; anal penetration was less common. 34.9% of the women practiced fellatio without protection, 16.3% had anal intercourse without protection. The proportion of AIDS cases in Mexico in women of reproductive age was growing at an exponential rate, possible because of misinformation about AIDS, a history of STDs, and a low rate of condom use.     

繁殖群中婴幼川金丝猴社会关系发展的个案研究

使用瞬时取样法,对繁殖笼内出生的两只婴幼川金丝猴进行连续22个月的行为记录。结果表明,川金丝猴婴猴断乳大约在19—20月龄;断乳表现为母婴之间矛盾冲突的过程;群内其他雌性对初生婴儿表现出明显的抢婴、护婴和育婴行为;父亲对婴幼猴表现出接纳和容忍的态度;婴儿在断乳前是群内全体成员保护和爱护的对象,以后开始进入社会关系网,受到成年个体的责备,但很轻微;雌性幼猴在32月龄时尚未被记录到对群内成员表现威胁、蜷缩和匍伏等行为模式。     

立体视觉的心理物理和VEP比较研究

心理物理试验是研究立体视觉的主要方法。70年代VEP开始用于体视研究,并取得许多结果。由于VEP信号复杂,这些结果不能令人满意。本文使用心理物理试验和VEP对比方法对体视加以研究。我们的结果是:VEP波形中第一个正峰与刺激图形的亮度有关;N_2峰和P_3峰的潜伏期对判断体视存在与否有重要价值;本试验确定N_2峰潜伏期在体视存在时约为240ms—280ms,无体视存在时约为290ms—310ms;P_3峰潜伏期在体视存在时约为280ms—310ms,无体视存在时约为340ms—360ms;体视存在时的VEP与无体视存在时的VEP的互相关系数小于0.1;有体视的VEP其功率谱密度在8Hz附近有一峰;心理物理试验中使用强制选择得到的结果从VEP波形比较中可以确认是可靠的;有体视的VEP其N_2和P_3的潜伏期随视差变化呈现规律性改变。