Choice with Concurrent Interval Schedules of Reinforcement: The Effects of Different Timing Procedures

Using a Findley changeover procedure, two groups of rats were exposed to various concurrent variable-time (VT) schedules of milk presentation. The rules governing the operation of the timers for the stimulus events differed for the two groups with resulting differences in the overall degree of changeover responding but not with respect to time allocation measures, which in both cases consisted of undermatching. When an interrupted VT reinforcement timer was reset upon re-entry of that component, the rats tended to emit changeover responses almost exclusively to the more favorable component. When the VT reinforcement timers were left running regardless of which components the rats selected, changeover responses were significantly more frequent and equally distributed among both the more and less favorable components. In comparing the present results with those from a similar procedure in which shock was used (Deluty & Church, 1978), it is apparent that what is basic to choice in concurrent interval schedules is not matching or some mathematical variation of it. Instead, it is a tendency to optimize on the basis of the favorability of the stimulus events and the contingencies regarding how those events are timed and administered.

     

A Piagetian perspective on mathematical construction

In this paper, we offer a Piagetian perspective on the construction of the logico-mathematical schemas which embody our knowledge of logic and mathematics. Logico-mathematical entities are tied to the subject's activities, yet are so constructed by reflective abstraction that they result from sensorimotor experience only via the construction of intermediate schemas of increasing abstraction. The ‘axiom set’ does not exhaust the cognitive structure (schema network) which the mathematician thus acquires. We thus view ‘truth’ not as something to be defined within the closed ‘world’ of a formal system but rather in terms of the schema network within which the formal system is embedded. We differ from Piaget in that we see mathematical knowledge as based on social processes of mutual verification which provide an external drive to any ‘necessary dynamic’ of reflective abstraction within the individual. From this perspective, we argue that axiom schemas tied to a preferred interpretation may provide a necessary intermediate stage of reflective abstraction en route to acquisition of the ability to use formal systems in abstracto.     

Converging operations on a basic level in event taxonomies

Research on object concepts has identified one level of abstraction as "basic" in cognition and communication. We investigated whether concepts for routine social events have a basic level by replicating the converging operations used to investigate object concepts. In Experiment 1, subjects were presented with event names from a taxonomy and were asked to list the actions comprising the event. Many more actions were listed at the middle than at the highest taxonomic level, without a further increase at the most specific level, paralleling the pattern of superordinate-, basic-, and subordinate-level object concepts. From these action lists, brief stories were composed for each event. In Experiment 2, subjects made pairwise similarity judgments on the stories. The mean similarity of events increased with specificity, as expected. But differentiation of categories (within-category similarity compared to between-category similarity) was highest for super-ordinates, contrary to results with object categories. In Experiment 3, subjects were fastest in recognizing actions as belonging to events named at the basic level. In Experiment 4, subjects predominantly chose basic-level terms to name stories. We conclude that event taxonomies do show basic-level structure, albeit a less sharply defined and less stable structure than in object taxonomies. The benefits and hazards of extending models of object concepts to other entities, such as social events, are discussed.     

Acquiring English at different ages: The English displacement effect and other findings

An analysis of the language backgrounds of 237 persons in a psychology department subject pool is presented. Specific findings indicate that (a) only about two-thirds of the subjects were native speakers of English, (b) native English speakers can be divided into several different groups on the basis of bilingual background and age of acquisition of their second language, (c) the number of native English speakers who would be considered ideal for psycholinguistic experiments in English (e.g., monolinguals and bilinguals who acquired a second language in or after adolescence) is only about a third of the sample, (d) nonnative English speakers appear to have their native, non-English-language abilities reduced as a function of their acquisition of English; that is, English appears to displace other languages that a person knows (the English displacement effect), and (e) age of English acquisition is shown to be an important factor, by correlating negatively with rated English abilities and reported Scholastic Aptitude Test (SAT) scores, and positively with rated ability in a non-English language.Portions of this research were first presented at the 59th annual meeting of the Eastern Psychological Association in Buffalo, New York, April 1988. I gratefully thank Doris Aaronson for the numerous comments she made on earlier versions of this paper.     

The GRIMS. A psychometric instrument for the assessment of marital discord

Research in marital therapy has been disadvantaged by the lack of a good, short and recent psychometric questionnaire to objectively assess the state of a marriage for research, demographic and clinical purposes. The Golombok Rust Inventory of Marital State (GRIMS) is a companion questionnaire to the Golombok Rust Inventory of Sexual Satisfaction (GRISS), and concentrates on aspects other than the sexual in a dyadic relationship between two adults living together. It is a 28 item psychometrically constructed inventory designed to produce a single scale along which changes in a marriage may develop as marital therapy progresses. It has been shown to be valid for this purpose, and to have a good reliability.     

Deontic logic and the possibility of moral conflict

Standard dyadic deontic logic (as well as standard deontic logic) has recently come under attack by moral philosophers who maintain that the axioms of standard dyadic deontic logic are biased against moral theories which generate moral conflicts. Since moral theories which generate conflicts are at least logically tenable, it is argued, standard dyadic deontic logic should be modified so that the set of logically possible moral theories includes those which generate such conflicts. I argue that (1) there are only certain types of moral conflicts which are interesting, and which have worried moral theorists, (2) the modification of standard dyadic deontic logic along the lines suggested by those who defend the possibility of moral conflicts makes possible only uninteresting types of moral conflicts, and (3) the general strategy of piecemeal modification standard dyadic deontic logic is misguided: the possibility of interesting moral conflicts cannot be achieved in that way.     

Implicit learning: Indirect, not unconscious

Dienes and Berry (1997) argue that there really are two kinds of knowledge, implicit and explicit, that can be characterized through a subjective threshold. We argue that the subjective threshold does not separate two forms of knowledge, but instead two uses of knowledge, for two different purposes. With Neal and Hesketh (1997), we suggest that an understanding of learning will be better served by investigating the processing that occurs under various circumstances than by attempting to isolate learning that occurs with awareness from that which occurs without it.     

Chicks Injected with Antisera to either S-100α or S-100β Protein Develop Amnesia for a Passive Avoidance Task

The cellular expression of S-100β protein is upregulated in Alzheimer's disease and in Down's syndrome, and this protein has been implicated in memory-related processes in laboratory animals. However, the possibility that the α subunit of S-100 is also involved in memory has not yet been examined. In the present study, day-old black Australorp white Leghorn cockerel chicks (Gallus domesticus) received injections of monoclonal antisera to S-100α (1:50) or S-100β (1:500) into each hemisphere immediately after training on a one-trial passive avoidance task. The chicks displayed significantly lower retention levels than control birds that had been injected with antisera to carbonic anhydrase, or with saline (p< .01). S-100α antisera had an amnestic effect when injected between 0 and 20 min after training, with memory deficits occurring from 30 min postlearning, at the point of transition between the A and the B phases of the Gibbs-Ng intermediate memory stage. By contrast, the S-100β antisera needed to be injected either 5 min before or immediately after training and produced amnesia 10 min earlier, at the start of the A phase of the intermediate memory stage. We conclude that the two subunits of the S-100 protein are required at different points in the sequence of events leading to the consolidation of passive avoidance memory.