After-effects of reinforcement magnitude: Dependence upon context

On a fixed-interval schedule with rat subjects the duration of the post-reinforcement pause was found to be an increasing function of the magnitude of the preceding reinforcer. This relationship was observed when two magnitudes were contrasted closely in time, but not when the subjects were trained on each magnitude until the establishment of stable responding. After the behaviour was stable, the effect of the magnitude of reinforcement re-emerged when 50% of the scheduled reinforcers were omitted. Thus, the positive relationship between the magnitude of reinforcement and the duration of the post-reinforcement pause depended on the context of presentation of a given magnitude.     

A note on a sufficiency condition for uniqueness of a restricted factor matrix

A counterexample is produced to a conjecture by K. G. Jöreskog concerning sufficiency conditions for uniqueness of a restricted factor matrix. A substitute condition is stated and proved for the most common situation where the restricted elements are specified to be zero.     

On the significance of “double encoding” for the superior recall of pictures to names

Ten-year-old children who were shown pictures of objects immediately preceded by the object's name recalled the material no better than those exposed to the names of the stimuli alone. Both conditions yielded significantly poorer retention than those in which pictures alone were presented or pictures followed by their names. A second study replicated this result. In addition this demonstrated, by a picture and name recognition task, that the effects could not be due to subjects in the “name prior to picture” condition ignoring the pictorial component. These results were interpreted as contradicting the “double encoding” explanation of the superiority of pictures to names in free recall. Parallel visual and verbal encoding of a pictured object does not facilitate retention unless the verbal cue is actively elicited from the subject by the stimulus. The implications of this result for other studies which have employed either simultaneous or sequential presentation of pictures and names are briefly discussed.     

What Happens when History Does Not Walk as We Wish?

The modern ecumenical movement calls the churches to pray together and to stay together. Through the World Council of Churches, this call has been supported by theological reflection, most notably on baptism, eucharist and ministry and, more recently, ecclesiology. It has also been nurtured by the missionary movement and its practical calls to common witness and service. This article sets out the context of the work of a parish church in Edinburgh, UK. It provides context to ecumenical and interfaith relations in the parish and to pastoral work within what is called the pink triangle. It concludes with a reflection on John Zizioulas's local church and considers the implications of an ecclesiology and missiology that reflect the life of the parish: “While cherishing the unity of the Spirit in the one Church, it is also important to honour the ways in which each local congregation is led by the spirit to respond to its own contextual realities.” 1     

Thinking the impossible

The article looks at the structure of impossible worlds, and their deployment in the analysis of some intentional notions. In particular, it is argued that one can, in fact, conceive anything, whether or not it is impossible. Thus a semantics of conceivability requires impossible worlds.