Effects of fixed-time shocks and brief stimuli on food-maintained behavior of rats

When a fixed-time schedule of shocks was presented to rats lever pressing for food on a random-interval schedule, a pattern of behavior developed with a high rate of pressing after shock declining to near zero before the next shock was delivered. Once this pattern had stabilized, one-quarter of the shocks were replaced with brief auditory stimuli (tones) in a random sequence. Tone maintained behavior similar to shock, although tone was never paired with shock. Both tone and shocks elicited responding when presented at various times as probe stimuli, and responding was usually totally suppressed if neither stimulus occurred at the beginning of the fixed-time interval. When other stimuli were paired with tone and shock, only those paired with tone gained discriminative control and elicited responding. These findings suggest that stimuli that signal a shock-free, or safe, period will maintain the pattern of behavior generated by shock on a fixed-time schedule. There is a parallel between this phenomenon and the control of behavior on second-order schedules of positive reinforcement with nonpaired brief stimuli.     

How would a latent period for early breast cancer affect the benefit of screening?

The ideal goal of a screening program for breast cancer is to detect the disease at a stage when it is still curable by a simple lumpectomy. This goal would be possible if the tumor had an early latent period before it was vascularized. However, even if there existed a harmless screening examination that was sensitive enough to discover the cancer at this stage the benefit to be gained from a screening program would be highly dependent on the time the tumor spends in the latent stage as well as on the chance of false negatives at the examination. Calculations derived from a mathematical model suggest a variety of theoretically possible situations including: (1) For certain cancers screening every three years would offer almost as much benefit as screening every year; (2) A large increase in the sensitivity of a screening examination does not necessarily lead to a large increase in the benefit of a screening program; (3) For certain cancers the benefit of screening might remain low no matter how sensitive the examination used.     

Units of phonological recoding of word-like stimuli used by children and adults

Third-grade, sixth-grade, and coUege-age subjects performed a “same”-“different” task, using a phonological identity criterion for visually presented pseudowords. Consistent with Krueger’s (1978) model of single-glance “same”-“different” judgments, judgments of phonologically matching stimuli were made more quickly and less accurately than were judgments of phonologically nonmatching stimuli, and error rates and RTs were longer for phonologically similar nonmatching pairs than for phonologically dissimilar nonmatching pairs. It was concluded that subjects of all ages tested could process phonologically recoded information in a holistic fashion, and the implications of these conclusions with respect to reading processes are discussed.     

The effects of lexical and semantic information on same-different visual comparison of words

Previous research has indicated that phonemic and orthographic factors cannot account for the fact that words (clear/clear) are responded to more rapidly than orthographically legal nonwords (creal/creal) in a same-different visual comparison task. However, the role of semantic and lexical factors is less certain. The effects of semantic similarity on both same and different judgments were evaluated in several experiments. In the first experiment, subjects were not any slower on semantically related (rang/rung) than on unrelated (rang/rank) different judgments even with a 3,000-msec interval between the first and second word. In Experiment 2, subjects based their judgments on whether or not the first letter of each word was visually identical. Same judgments were not any faster for semantically related than unrelated items even though other evidence indicated that subjects were processing the whole word and not just the first letter. Experiment 3 showed that the word/orthographically legal nonword difference could be replicated with the first-letter visual comparison task employed in Experiment 2. These and related results were discussed with reference to the idea that the word/orthographically legal nonword difference is due to the facilitating effects of a lexical entry upon the encoding, but not the comparison of an item.     

Children's beliefs about adoption: A developmental study

Attributions about adoption were examined in adopted and nonadopted children between the ages of 6 and 13 years. Results indicated that nonadopted children had a more negative view of adoption than their adopted age-mates, at least during the early to middle childhood years. By 10–11 years, however, no group difference was noted in adoption beliefs. In addition, with increasing age nonadopted children became less negative about adoption whereas adopted children became more negative about adoption. These results are discussed in the context of differential socialization for adopted and nonadopted children. Implications of adoption beliefs for children's adoption adjustment also are raised.     

Children's occupational sex-typing

Preschool and elmentary school children responded to questions measuring sex-typing of attribution (who would like this job), service preference (who the child would choose to do this job), and personal job choice (would the child like to do this job) dimensions for each of nine jobs, and stated a free-choice job preference. A subsample completed a cognitive classification measure. With age through second grade attribution and service preference sex-typing increased; generally, the match scores between the three aspects and census reality increased; the use of sex-typed categories in service preference decreased. For some aspects, girls were less sex-typed than boys; for others, each sex showed own-sex bias. Age, not classification skill, accounted for more variance in the sex-typing measures.This research was supported in part by an Indiana University Grant-in-Aid for dissertation research awarded to the first author. A shorter version of this article was presented as a paper at the annual meeting of the American Psychological Association, Toronto, 1978. The authors would like to thank the children, parents, and school personnel in all five cooperating schools, including Central Elementary School, David Satter, Principal; Children's Corner Cooperative Nursery School, Sue Yamaguchi, Director; Christian Center Day Care Preschool, Monroe County United Ministries, James Fisbo, Executive Director, Jean K. Lloyd, Preschool Director; St. Charles School, Kathleen Fleming, Principal.     

A review of observer reactivity in adult-child interactions

The present article reviews studies which have examined the question of observer reactivity in adult-child interactions. Seventeen studies were located. Studies were classified according to the paradigm used to examine reactivity, the setting in which the study was conducted, the identification of the child as a behavior problem, and the occurrence and direction (i.e., increases or decreases in the observed behavior) of reactivity. The results indicated that the awareness paradigm has been employed most frequently, the laboratory has been the primary setting utilized, and problem and nonproblem children have been employed with approximately equal frequency. Reactivity was reported in about three-fourths of the studies. For adults positive and neutral verbal and physical behaviors were more reactive than negative behaviors. The positive and neutral behaviors typically increased in the observer's presence. For children conclusions are not warranted at this time as too few studies have examined children's behavior.Preparation of this article was supported in part by NIMH Grant MH28859-01.     

The Relationship Between the Francis Scale of Attitude Toward Christianity and Measures of Intrinsic,Extrinsic and Quest Religiosity

A sample of 244 churchgoers completed the Francis Scale of Attitude toward Christianity, together with measures of intrinsic, extrinsic and quest religiosity proposed by Batson. The findings support the view that, among a religiously committed sample, a positive attitude toward Christianity is associated positively with intrinsic religiosity and negatively with both extrinsic religiosity and quest religiosity. Pastoral Theology and Mansel Jones Fellow at     

Mapping of the Anatomical Circuit of CaM Kinase-Dependent Courtship Conditioning in Drosophila

Globally inhibiting CaM kinase activity in Drosophila, using a variety of genetic techniques, disrupts associative memory yet leaves visual and chemosensory perception intact. These studies implicate CaM kinase in the plastic processes underlying learning and memory but do not identify the neural circuitry that specifies the behavior. In this study, we use the GAL4/UAS binary expression system to define areas of the brain that require CaM kinase for modulation of courtship conditioning. The CaM kinase-dependent neurons that determine the response to the mated female during conditioning and those involved in formation and expression of memory were found to be located in distinct areas of the brain. This supports the idea that courtship conditioning results in two independent behavioral modifications: a decrement in courtship during the conditioning period and an associative memory of conditioning. This study has allowed us for the first time to genetically determine the circuit of information flow for a memory process in Drosophila. The map we have generated dissects the behavior into multiple components and will provide tools that allow both molecular and electrophysiological access to this circuit.