Economic and biological influences on key pecking and treadle pressing in pigeons

Pigeons were studied on a two-component multiple schedule in which the required operant was, in different conditions, biologically relevant (i.e., key pecking) or nonbiologically relevant (i.e., treadle pressing). Responding was reinforced on a variable-interval (VI) 2-min schedule in both components. In separate phases, additional food was delivered on a variable-time (VT) 15-s schedule (response independent) or a VI 15-s schedule (response dependent) in one of the components. The addition of response-independent food had different effects on responding depending on the operant response and on the frequency with which the components alternated. When components alternated frequently (every 10 s), all pigeons keypecked at a much higher rate during the component with the additional food deliveries, whether response dependent or independent. In comparison, treadle pressing was elevated only when the additional food was response dependent; rate of treadling was lower when the additional food was response independent. When components alternated infrequently (every 20 min), pigeons key pecked at high rates at points of transition into the component with the additional food deliveries. Rate of key pecking decreased with time spent in the 20-min component when the additional food was response independent, whereas rate of pecking remained elevated in that component when the additional food was response dependent. Under otherwise identical test conditions, rate of treadle pressing varied only as a function of its relative rate of response-dependent reinforcement. Delivery of response-independent food thus had different, but predictable, effects on responding depending on which operant was being studied, suggesting that animal-learning procedures can be integrated with biological considerations without the need to propose constraints that limit general laws of learning.     

FUNCTIONAL ANALYSIS OF EPISODIC SELF-INJURY CORRELATED WITH RECURRENT OTITIS MEDIA

A functional analysis examined the consequences that maintained episodic self-injury and the relationship between those consequences and otitis media for a child with moderate developmental disabilities. Results indicated that self-injury occurred only during periods of otitis media. Otitis media may have served as an establishing operation related to escape from ambient noise.     

Categorization of natural movements by pigeons: visual concept discrimination and biological motion

In three experiments, pigeons were exposed to a discriminated autoshaping procedure in which categories of moving stimuli, presented on videotape, were differentially associated with reinforcement. All stimuli depicted pigeons making defined responses. In Experiment 1, one category consisted of several different scenes of pecking and the other consisted of scenes of walking, flying, head movements, or standing still. Four of the 4 birds for which pecking scenes were positive stimuli discriminated successfully, whereas only 1 of the 4 for which pecking was the negative category did so. In the pecking-positive group, there were differences between the pecking rates in the presence of the four negative actions, and these differences were consistent across subjects. In Experiment 2, only the categories of walking and pecking were used; some but not all birds learned this discrimination, whichever category was positive, and these birds showed some transfer to new stimuli in which the same movements were represented only by a small number of point lights (Johansson's “biological motion” displays). In Experiment 3, discriminations between pecking and walking movement categories using point-light displays were trained. Four of the 8 birds discriminated successfully, but transfer to fully detailed displays could not be demonstrated. Pseudoconcept control groups, in which scenes from the same categories of motion were used in both the positive and negative stimulus sets, were used in Experiments 1 and 3. None of the 8 pigeons trained under these conditions showed discriminative responding. The results suggest that pigeons can respond differentially to moving stimuli on the basis of movement cues alone.     

Personality factors of individuals who survive traumatic experiences without professional help

This is a study of the personality resources that enable certain individuals to cope successfully with traumatic experiences without planned psychotherapeutic intervention. A survey of 40 trauma-surviving respondents reveals some common positive developmental and psychosocial factors. Also, five cases are described who experienced serious trauma, three of them living successful lives and two remaining disabled. The biological predisposition and the specific interaction of ones nature and nurture leading toward resolution of traumatic experiences are discussed. Individuals who have survived Posttraumatic Stress Disorder should be studied further within a psychobiological framework.     

The effects of a vitamin supplement on the pica of a child with severe mental retardation

The effects of a common multiple vitamin on the pica of a child with severe mental retardation and anemia were evaluated. A BAB design revealed that pica was decreased by the vitamin. The results suggest that pica can be effectively treated by implementation of a simple nutritional or biological intervention. Further research investigating the generality of this finding and the effects of combining biological and behavioral interventions are discussed.     

Reparations and the Rectification of Race

Positive law and problems with identifyingbeneficiaries confine reparations for U.S.slavery to the level of discourse. Within thediscourse, the broader topic of rectificationcan be addressed. The rectification of slaveryincludes restoring full humanity to our ideasof the slaves and their descendants and itrequires disabuse of the false biological ideaof race. This is not racial eliminativism,because biological race never existed, but moreimportantly because African American racialidentities and redress of present racism arebased on lifeworlds of race in contrast withwhich the biological idea has been an externalimposition.     

纳米细菌与冠心病

最近新发现的纳米细菌是目前已知的最小的细菌,其直径为几十至几百纳米.与其它细菌不同,它们是一种生长繁殖缓慢,能通过普通滤菌器(0.2um),吴有生物矿化作用和一定抗辐射能力,革兰氏染色阴性的球形细菌.它们最特殊的生物学特性是可以在生理状态的钙、磷浓度下分泌主要由羟磷石灰碳酸盐构成的保护性外壳.因此,它们被认为与机体内病理性钙化密切相关.近年来研究发现,它们可能是冠心病的一种感染性致病源.抗纳米细菌治疗的临床实验显示在冠心病患者中具有一定疗效.     

学前儿童朴素生物学研究新进展:活力因果机制及其应用

学前儿童倾向于采用活力因果机制,即用生命力的交换和获取来解释与机体有关的生命现象.活力因果解释介于意图因果解释和机制因果解释之间,被认为是专属于生物领域的一种因果认知机制,它的提出为存在独立的朴素生物学理论提供了强有力的证据.4到6岁是活力机制发展的关键时期.同时,在年长儿童和成人对机体生命现象的认识中,这一机制继续发挥着作用,并不会随着儿童年龄的增长被其它因果机制完全取代.探讨可能导致活力因果机制发展差异性的影响因素以及它与其它因果机制的共同作用将是未来研究的方向.     

Physical home environment is associated with prefrontal cortical thickness in adolescents

Biologically embedded experiences alter developmental trajectories in ways that can influence health, learning, and/or behavior. These systematic differences in experiences may contribute to different biological outcomes as individuals grow and develop, including at the neural level. Previous studies of biologically embedded experiences on neurodevelopment have focused on large‐scale institutional or economic factors (e.g. socioeconomic status [SES]) and psychosocial factors (e.g. caregiving behavior). Less attention has focused on how the quality of the immediate home settings, such as the physical home environment (PHYS), influences neurodevelopment. Moreover, no study has investigated these effects in adolescents, who undergo significant physical maturation and neurodevelopment that may influence how they respond to their physical environments. The goal of the current study was to examine whether PHYS quality is biologically embedded in the developing adolescent brain as evidenced by cognitive achievement and cortical development in 56 (48% female) healthy adolescents (14–18 years (M = 16.83 years, SD = 1.17). Using in‐home assessments of the physical home environment, anatomical brain scans, and indices of academic achievement, we found that adolescents who have more physical problems in the home (e.g. structural hazards, crowding, excessive noise, poorly lit) have thinner prefrontal cortices, which was associated with lower levels of reading achievement, independent of SES and psychosocial factors. By conducting home visits to assess physical characteristics of adolescents’ home, we highlight a typically overlooked aspect of the home environment that has relevance for adolescents’ cognitive and brain development.