What Can the Systems Community Contribute to Ensure the Survival of Civilization

Much of what we need to plan for our survival is already known, but what we know, how we know, and who knows is divided up between disciplines. Thus much of the problem of ensuring our survival is a matter of learning across the disciplines. We identify four modes through which we bring disciplinary knowledge together: the unity of science, integrated assessment, heuristic models, and distributed learning networks. Although none of them are perfect, we can learn how to put our knowledge together across the disciplines much better than we do.     

Instrumental responding following reinforcer devaluation

In two experiments, hungry rats were given instrumental lever-press training for an appetitive reinforcer and, in addition, were exposed to another type of food which was not contingent on lever pressing. In the first experiment, exposure to each type of food was on separate days, whereas in the second experiment rats were exposed to each type of food in strict alternation within each session. Subsequently, a food aversion was conditioned to the reinforcer for the experimental group and to the non-contingent food for the control group. In both experiments, animals with an aversion to the reinforcer responded less in an extinction test than animals with an aversion to the non-contingent food. Subsequent reacquisition tests confirmed that the aversion to the non-contingent food in the control group was of comparable strength with that to the reinforcer in the experimental group. The results were discussed in terms of whether the reinforcer is encoded in the associative structure set up by exposure to an instrumental contingency.     

The Interpretation of Anaphoric Noun Phrases Time Course, and Effects of Overspecificity

Two experiments investigated the interpretation of anaphoric noun phrases, and in particular those thatcould only be linked to their antecedents via knowledge-based inferences. The first experiment showed that much of the inferential processing was carried out as the anaphoric noun phrase was read, although there was some indication that inferential processing continued to the end of the clause. The second experiment attempted to establish why anaphoric noun phrases that are more specific than their antecedents cause problems. It showed that the difficulty did not lie in adding the extra information carried by the anaphor to the representation of the referent. Rather, we suggest, putting extra information in the anaphoric noun phrase disrupts the process of linking that noun phrase to its antecedent.