Choice of extinction-signalling stimuli by rats

Rats in a two-lever situation were exposed to alternating periods of intermittent reinforcement and extinction. Extinction periods were either unsignalled or were signalled by a response-produced stimulus. The signal was sometimes a stimulus paired with food delivery in the reinforcement periods and sometimes a stimulus that occurred only in extinction periods. Both kinds of signal accelerated extinction relative to the unsignalled condition. When the signal was the stimulus paired with food in reinforcement periods, the rats tended to prefer the lever that gave that signal even though the signal accelerated extinction. There was no comparable effect for the stimulus that occurred only in extinction periods; when this signal was contingent on only one of the two levers, the rats either avoided it (Experiment 3) or were indifferent (Experiment 4). It is concluded that a stimulus can be a “secondary reinforcer” as measured by preference, even though it decreases resistance to extinction; the implications are discussed with reference to formal theories of choice behavior.     

Precocious conservation in context: The solution of quantity tasks by nonquantitative strategies

C. Sinha and B. Carabine's (1981, Journal of Child Language, 8, 109–129) claim of a U-shaped course to the development of quantitative knowledge with an early stage of conservation based on functional significance was tested in two experiments. Children at three age groups from 3 to 6 years were presented with the original procedure or control versions in which the display was slightly altered. Results showed that although Sinha and Carabine's result was replicable, their interpretation is unwarranted. Performance in the younger groups was best interpreted as the use of nonquantitative possession or position strategies.     

Choice reaction performance following an error

Some data are presented showing the changes in choice-reaction time (CRT) and the probability of error (PE) on the five trials following an error in a two-choice experiment. The magnitudes of the increase in RT and the decrease in PE are different according as the error-trial stimulus is re-presented or the alternative stimulus is preservec. In addition, RT is quicker to recover its equilibrium value than is PE.This pattern of changes implicates two distinct adjustments to the underlying decision process following an error: (i) a selective outward adjustment of the boundary at which the error was uttered, and (ii) a delay, with respect to presentation of the reaction stimulus, of the epoch at which the subject begins sampling information from the stimulus display. When these ideas are concatenated with the sequential probability-ratio-test model for CRT, a theoretical relation can be derived between the difference in mean RT for an error and for the same response given correctly, on the one hand, and the decrease in PE on the trial following an error, given that the alternate stimulus is presented, on the other. This relation is satisfied by the data.     

Autocorrelation of choice-reaction times.

A choice-reaction (CR) task requires that the subject estimate, raking the warning signal or his response on the preceding trial as a reference point, the time when the reaction stimulus is due, so that he can begin deciding on his response at an appropriate time. This paper presents a model for the reproduction of temporal intervals, with particular emphasis on the sequential statistics of a series of such reproductions. When this model is concatenated with the sequential probability ratio test model for 2CRT, it provides a quantitative account of the pattern of autocorrelation found in a series of RTs. There is no corresponding autocorrelation in the incidence of errors, however, because after an error the subject systematically adjusts the epoch at which he begins sampling as a precaution against a further error. These post-error adjustments can readily be incorporated into the model. The ideas presented enable several different CR phenomena to be related, and they have implications for the relation between speed and accuracy, for the form of empirical distributions of RTs, and for the effects of temporal uncertainty.     

A critical comparison of two random-walk models for two-choice reaction time

Two random-walk models for two-choice reaction time, being the sequential probability ratio test model initially suggested by Stone and the relative judgment theory recently proposed by Link, are here compared. The comparison shows the precise mathematical relation between the models, the predictions they have in common, and two points at which they differ. Three experiments concerned with the effect of stimulus probability on two-choice reaction time are examined with respect to three predictions from the models. In this three-way comparison the two models are more like each other than either is to the data; a greater variety of phenomena is revealed than either model can at present accommodate.     

Nest material and food as reinforcers for fixed-ratio responding in mice

Three experiments investigated the importance of operant-reinforcer distance as a factor affecting continuous reinforcement (CRF) and fixed-ratio (FR) performance in mice, with nest material and food as reinforcers. In Experiment 1, nest material (paper strips) was presented on a series of FR schedules of increasing size, with the operandum located as close as possible to the reinforcer dispenser. Subjects compensated for increases in FR size by proportionately increasing their response output, but ratio strain occurred at low FR values. In Experiment 2, response rate was found to be inversely related to operant-reinforcer distance on a CRF schedule with nest material as reinforcer. In Experiment 3, food was presented on a series of FR schedules at two levels of deprivation, and with three operant-reinforcer distances. Operant-reinforcer distance was found to affect CRF response rate, degree of compensation for increases in FR size, and occurrence of ratio strain, but only when deprivation level was low. The results support the view that nest material and food share fundamentally similar reinforcing properties, but that nest material is a weaker reinforcer under normal test conditions.     

Vocational maturity in adulthood: Toward turning a model into a measure

It is postulated that adult vocational maturity needs to be assessed because of the changing developmental tasks encountered during the course of a career. Vocational maturity having been found to be multidimensional, existing undimensional inventories of adult vocational maturity are considered of limited although demonstrated validity. Relevant theories of adult vocational development and adjustment are reviewed. Super's proposed adult vocational maturity model is examined for the promise that it offers and for the problems that arise in developing a multidimensional measure of vocational maturity. A way of surmounting these problems is proposed as a basis for work now being undertaken.     

The effects of S-R uncertainty in the PRP paradigm: A reply to Kantowitz

Karlin and Kestenbaum (1968) reported a series of apparently complex interactions between S-R uncertainty and RT in an experiment using the psychological refractory period paradigm. McLeod (1977) showed that these effects could be predicted by a parallel processing limited capacity model. Kantowitz (1978) criticised that paper on the grounds that it paid insufficient attention to the predictions of response conflict theory and made no mention of errors.It will be shown (a) that response conflict theory, as described by Kantowitz, fails to predict the effects found by Karlin and Kestenbaum (b) that the comments about errors miss the point of McLeod (1977) (c) that in his final section Kantowitz falls into an old trap which awaits the unwary analyser of PRP data.     

Errors in children's subtraction

Many of the errors that occur in children' subtraction are due to the use of incorrect strategies rather than to the incorrect recall of number facts. A production system is presented for performing written subtraction which is consistent with an earlier analysis of the nature of such a cognitive skill. Most of the incorrect strategies used by schoolchildren can be accounted for in a principled way by simple changes in the production system, such as the omission of individual rules or the inclusion of rules appropriate to other arithmetical tasks. The production system model is evaluated against a corpus of over 1500 subtraction problems done by 10-year olds and is shown to account for about two-thirds of the (nonnumber fact) errors. It also provides an alternative, simpler interpretation of the subtraction errors analysed by Brown and Burton (1978). Some implications for teaching are discussed.     

Commentary on social class differences in sociodramatic play in historical context: A reply to McLoyd

Historical origins of the research on the cultural correlates of imaginative behavior by the Israeli psychologists Feitelson, Smilansky, and Eifermann are presented. It is argued that despite McLoyd's searching analysis of the deficiencies in studies which attempt to relate level of imaginative play to social class, those earlier cross-cultural studies, together with some 50 years of prior research on social class and play in general, provide a context which gives support to those studies despite their particular methodological deficiencies.     

The demonstration of capacity limitation

The study of divided attention has produced many apparent demonstrations of “capacity limitation.” Possible ambiguities in such demonstrations are considered for three major types of experimental situation: simultaneous inputs with separate responses; choice; and classification. Two issues emerge. First, demonstrations always rest on assumptions about process set, i.e., the set of internal processes by which the task actually is performed. Alternative process sets are considered for situations of each type. Second, a demonstration of capacity limitation is made either by increasing the number of simultaneous processes, or by changing the bias between them. In either case effects unrelated to capacity limitation may influence the results. If several processes contribute to a single response, some performance decrement must accompany an increase in their number, simply through the increased overall chance for error. If the subject is biased toward one alternative in a choice or classification situation, the benefits enjoyed by this alternative may reflect not a preferential allocation of attentional capacity, but simply a willingness to decide in favor of this alternative with relatively little evidence.     

The voice of confidence: Paralinguistic cues and audience evaluation

A standard speaker read linguistically confident and doubtful texts in a confident or doubtful voice. A computer-based acoustic analysis of the four tapes showed that paralinguistic confidence was expressed by increased loudness of voice, rapid rate of speech, and infrequent, short pauses. Under some conditions, higher pitch levels and greater pitch and energy fluctuations in the voice were related to paralinguistic confidence. In a 2 × 2 design, observers perceived and used these cues to attribute confidence and related personality traits to the speaker. Both text and voice cues are related to confidence ratings; in addition, the two types of cue are related to differing personality attributes.     

Rhythm and dominance

Subjects were tested by a short experimental procedure involving tapping of a rhythm with one limb with a simultaneous regular beat with another limb. Informal observations had suggested a rhythm dominance effect—that is was dramatically easier with some limb combinations. Notably it was easy when the right hand tapped the rhythm and the left hand the beat but almost impossible the other way round. Equally, both hands dominated both feet. Our tests revealed enormous individual differences, subjects separating neatly into three groups. Some people could not do the task at all, some could do it with any limb combination, the latter group including all the serious musicians tested. For the remainder the rhythm dominance effect was clear. However, the laterality effect was the same (right hand advantage) for a majority (60%) of left handers. We conclude, then, that this effect is linked to language dominance and not handedness. In addition it seems there is a task scheduler which imposes its own view in combining this laterality effect with the dominance of hands over feet.     

The role of short-term working memory in mental arithmetic

A series of experiments explored the role of information storage in working memory in performing mental arithmetic. Experiment 1 assessed the strategies people report for solving auditorily presented multidigit problems such as 325 + 46. As expected, all subjects reported breaking down the problems into a series of elementary stages, though there were considerable individual differences with regard to the order of their execution. Strategies of this type necessitate both the temporary storage of information and the mobilization of long-term knowledge. Experiments 2 and 3 examined the effects of delaying the output of individual partial results on calculation accuracy and showed that interim information is forgotten if it is not utilized immediately. Experiment 4 showed that forgetting the initial information is also a source of error and suggested that forgetting increases as a function of the number of calculation stages intervening between initial presentation and subsequent utilization of information. Two simple quantitative models were derived from a general task analysis, one of which assumed a decay process in working storage and the other no decay. The decay model gave a reasonable fit to data from Experiments 2–4, and in doing so it coped appreciably well with the effects of a large variety of task variables (e.g., carrying, the provision of written notes, calculation strategy, output order). The decay model is a tractable analysis of a complex task, and it is suggested that similar analyses may prove fruitful for other problem-solving activities which involve the use of working memory.     

Remembering plurals: Unit of coding and form of coding during serial recall

Subjects were required to recall lists of six words which had been presented visually in sequence. One or two of the words might be plural nouns. A substantial number of errors occurred in which the plural form became detached from its original root. This is taken as evidence for a morpheme-based code as opposed to a unitary word code. A significantly high proportion of these errors maintained the form of the plural ( /S/, /Z/ or (ЪZ/) which is considered evidence for a primarily phonological coding of the plural morpheme. There is however a suggestion that on some occasions the plural is coded morphemically—i.e., in a way which does not distinguish between the various plural endings.     

Individualized learning environments: Intra- and interpersonal consequences

This study examines the effects of individual goal structures on the intra- and interpersonal behavior of 120 fourth-grade children. Each group of four children was introduced to one of two individualized learning programs: (a) workbook materials color-coded according to level of difficulty (allowing implicit comparisons among children as to progress), and (b) materials not coded according to difficulty (discouraging comparisons). In both learning programs, children worked individually (at story writing) and were rewarded for the work. Results indicate that boys, but not girls, who were rewarded equally for doing good work in an individualized setting but who start and end at a lower step than other more frequently took away a toy from those peers with whom they compared themselves than did boys who were rewarded equally for good work and where there were no comparisons. Boys as a group, regardles of condition, gave more prize tickets to themselves than to others and gave more prize tickets to themselves than girls gave either to themselves or others. Both boys and girls appear to adopt the evaluations of their work given by the experimenter and appear to be influenced thereby in later prized-giving to themselves and to others.     

The nature of curiosity in children

This study examined several behaviors claimed to reflect curiosity in order to determine whether there are one or more types of curiosity. A secondary purpose was to examine the relations between the one or more types of curiosity and sex, social class, intelligence, achievement level, and ratings of personality traits. In two individual sessions 84 American first-grade boys and girls were administered five tasks which measured observation of complex and simple stimuli, preference of complex and simple stimuli, preference for the unknown, structure of meaning, and object exploration. A normalized Varimax factor analysis allowed the extraction of five factors: manipulatory curiosity, perceptual curiosity, conceptual curiosity, curiosity about the complex, and adjustive-reactive curiosity. Only the first factor was related to a demographic variable, sex. The nature of the factors and their theoretical and practical significance are discussed.     

Differences or deficits? The significance of pretend and sociodramatic play

The developmental significance of pretend and sociodramatic play remains unresolved. Quite possibly, such play experiences facilitate a range of developmental competences which other experiences (including focused training) can facilitate equally effectively. If this were so, individual differences in such forms of play need not be a matter of direct concern in themselves. Such differences could be related to proximate variables which would be of greater scientific significance than broader or vaguer social class labels, although the political and economic realities of socioeconomic status should not be forgotten.