How cells communicate: the system used by slime moulds

The way in which cells in multicellular organisms communicate and inform each other of their presence and relative position is an intriguing but mysterious problem. The form of communication used during the phase of aggregation in the cellular slime moulds represents a particularly amenable system for study. When these organisms run short of nutrients, some of the cells of the amoebal population emit rhythmic pulses of cyclic adenosine monophosphate. These chemical signals are slowly relayed to all the other amoebae within range and bring about an ordered migration of them towards the pulsating centre and the triggering of cellular development.     

Intergenerational transmission of warm-sensitive-stimulating parenting: a prospective study of mothers and fathers of 3-year-olds

More than 200 New Zealand men and women studied repeatedly since age 3 were videotaped interacting with their own 3-year-old children to determine (a) whether childrearing and family climate experienced in 3 distinct developmental periods while growing up (i.e., early childhood, middle childhood, early adolescence) predicted parenting and (b) whether romantic relationship quality moderated the effect of childrearing history on observed parenting. Support for the first hypothesis emerged across all 3 developmental periods for mothers (only), with no evidence of moderating effects of romantic relationship quality for mothers or fathers. Results are discussed in terms of supportive versus harsh parenting, mother-father differences, and the characteristics of the sample.     

The effect of mindfulness on extinction and behavioral resurgence

In the present experiments, we investigated the effects of mindfulness on behavioral extinction and resurgence. Participants received instrumental training; either they received FI training (Experiment 1), or they were trained to emit high rates and low rates of response via exposure to a multiple VR yoked-VI schedule prior to exposure to a multiple FI FI schedule in order to alter their rates of responding learned during Experiment 2. Participants were then exposed to either a focused- (mindfulness) or an unfocused-attention induction task. All participants were finally exposed to an extinction schedule in order to determine whether a mindfulness induction task presented immediately prior to extinction training affected extinction (Experiment 1) and behavioral resurgence (Experiment 2). During the extinction phase, the rates of responding were higher in the control group than in the mindfulness group, indicating that the mindfulness group was more sensitive to the contingencies and, thus, their prior performance extinguished more readily (Experiment 1). Moreover, rates of response in the extinction components less precisely reflected previous training in the mindfulness group, suggesting less resurgence of past behaviors after the mindfulness induction (Experiment 2).     

Priced Out?

While the literature on postsecondary student success identifies important academic and social factors associated with student outcomes, one question that persists concerns the influence of financial aid. We use the National Student Clearinghouse’s StudentTracker service to develop a more complete model of student success that accommodates opportunities for students to choose to either graduate from the university of first-entry, graduate from a transfer university, or depart from college without a degree. The multinomial regression model reveals differential effects of financial aid. Results suggest that loan aid appears to encourage students to search out alternative institutions or drop out of college entirely, and merit aid appears to increase the likelihood of students persisting and graduating from the university of first-entry.     

Extinction of enhanced latent inhibition

Hungry rats were used in a classical conditioning procedure in which visual stimuli were paired with food. Conditions in which nonreinforced exposure to a nontarget stimulus was followed by exposure to a simultaneous compound nontarget/target stimulus (a blocking procedure) resulted in enhanced latent inhibition to the target relative to exposure to the nontarget, followed by exposure to the target stimulus alone. A third phase of nonreinforced exposure training, in which the target was exposed alone following the compound, reduced levels of latent inhibition relative to results obtained with the blocking procedure. Experiments also suggested that this was not the result of restoration of associability by the omission of an expected presentation of the nontarget stimulus in the final preexposure phase. These results suggest that enhanced latent inhibition is due to summation of a direct-target-no-event association and a second-order association of these elements via target-nontarget and nontarget-no-event association. Exposure to the target after compound exposure extinguished the target-nontarget association and reduced the sources of no-event learning for the target.     

The role of response-reinforcer correlation in signaled reinforcement effects

In three experiments, we examined the effects of signaling reinforcement during operant responding in order to illuminate the factors underlying instrumental overshadowing and potentiation effects. Specifically, we examined whether signaling reinforcement produces an enhancement and attentuation of responding when the response-reinforcer correlation is weak and strong, respectively. In Experiment 1, rats responded on variable-ratio (VR) or variable-interval (VI) schedules that were equated for the number of responses emitted per reinforcer. A signal correlated with reinforcement enhanced response rates on the VR schedule, but attenuated response rates were produced by the signal on the VI schedule. In Experiment 2, two groups of rats responded on a VI schedule while the two other groups received a conjoint VI, negative fixed-ratio schedule in which the subjects lost the availability of reinforcements if they emitted high response rates. A reinforcement signal attenuated responding for the simple VI groups but not for the animals given the negative fixed-ratio component, although the signal improved response efficiency in both groups. In Experiment 3, a poor correlation between responding and reinforcement was produced by a VI schedule onto which the delivery of response-independent food was superimposed. A signal for reinforcement initially elevated responding on this schedule, relative to an unsignaled condition; however, this pattern was reversed with further training. In sum, the present experiments provide little support for the view that signaling reinforcement enhances responding when the response-reinforcer correlation is weak and attenuates responding when this correlation is strong.     

Understanding Learning Culturally: Overcoming the Dualism Between Social and Individual Views of Learning

This paper identifies limitations within the current literature on understanding learning. Overcoming these limitations entails replacing dualist views of learning as either individual or social, by using a theory of learning cultures and a cultural theory of learning, which articulate with each other. To do this, we argue that it is possible and indeed necessary to combine major elements of participatory or situated views of learning with elements of Deweyan embodied construction. Bourdieu’s concepts of habitus and field are used to achieve this purpose, together with the use of ‘becoming’ as a metaphor to help understand learning more holistically. This theorizing has a predominantly heuristic purpose, and we argue that it enables researchers to better explain data. We also suggest that a cultural approach of the sort proposed here leads toward the asking of better questions about learning and its improvement and has high practical significance.

Child sexual abuse: A study of prevalence in Great Britain

Of 2019 men and women (aged 15 years and over) interviewed as part of a MORI Survey of a nationally representative sample of Great Britain, 10% reported that they had been sexually abused before the age of 16 (12% of females; 8% of males). There was no increased risk associated with specific social class categories or area of residence. For all types of sexual abuse, the mean age of victims when first abused was significantly lower for females. Subjective reports of the effects of sexual abuse indicated that the majority (51%) felt harmed by the experience, while only 4% reported that it had improved the quality of their life. We estimate that there are over 4.5 million adults in Great Britain who were sexually abused as children, and that a potential 1,117,000 children will be sexually abused before they are 15 years of age. At least 143,000 of these will be abused within the family. The social and mental health implications are enormous, and the authors suggest that an effective intervention and prevention policy is urgently required.     

Making a class act: as seen in one Year 8 English lesson

This article reports on active teaching and learning approaches taken by one English teacher and a secondary PGCE student‐teacher to bring about changes to the work culture in a Year 8 mixed‐ability class. It is written by the PGCE tutor, student‐teacher, class teacher and external examiner, following an observation of one lesson, in a series of lessons, given by the student‐teacher. This lesson is analysed through its motivating content, approach to critical reading, inherent creativity and active approaches to learning. It indicates how a challenging class has been changed by approaches that provide alternatives to currently advocated objectives‐driven and direct instructional approaches.