Delayed reinforcement and delayed choice in symbolic matching to sample: Effects on stimulus discriminability

Six pigeons were trained to peck a red side key when the brighter of two white lights (S₁) had been presented on the center key, and to peck a green side key when the dimmer of two white lights (S₂) had been presented on the center key. Equal frequencies of reinforcers were provided for the two types of correct choice. Incorrect choices, red side-key pecks following S₂ presentations and green side-key pecks following S₁ presentations, resulted in blackout. With 0-s delay between choice and reinforcement, the delay between sample presentation and choice was varied from 0 to 20 s. Then, with 0-s delay between sample presentation and choice, the delay between choice and reinforcement was varied from 0 to 20 s. Both types of delay resulted in decreased discriminability (defined in terms of a signal-detection analysis) of the center-key stimuli, but delayed choice had more effect on discriminability than did delayed reinforcement. These data are consistent with the view that the two kinds of delay operate differently. The effect of a sample-choice delay may result from a degradation of the conditional discriminative stimuli during the delay; the effect of a choice-reinforcer delay may result from a decrement in control by differential reinforcement.     

Delayed matching in the capuchin monkey with brief sample durations

Two capuchin monkeys were trained in a delayed matching-to-sample task in which the duration that the sample was available for viewing was very brief, 0.075 to 0.45 sec. The matching performance of one animal was above chance with delay (retention) intervals as long as 4 min; the other S showed significant matching with a 2-min retention interval. The performance of both Ss was independent of sample exposure duration, indicating that their capacity to match successfully at long retention intervals is not dependent on repeated viewing of the sample stimulus. The marked practice effect shown by one S with prolonged training at 2-min delay suggests the capacity of “learning how to remember.” A constant high performance level on 2-sec delay control trials indicates that the observed practice effect was not the result of enhanced attending to the sample stimulus.     

Development of relational learning: Effects of instruction and delay of transfer

Preschool children were trained on a color relevant oddity problem by one of three methods: increased salience of the oddity relationship, instruction on the solution rule, or a combination of increased salience and rule instruction. The youngest Ss solved the training problem when the solution rule was provided but not under the salience procedure. The two older groups solved in all conditions and errors decreased with age. The generality of the solution was determined by performance on a form relevant transfer task. The youngest Ss made fewer errors on the transfer problem following rule instruction training than following training in the combined procedure. The intermediate age group made fewer errors when the transfer task was administered one week after training than one minute after training. The transfer problem was easily solved by the oldest Ss and performance was independent of training procedure and amount of delay. These results were interpreted as reflecting developmental differences in relational concept learning.     

Mnemonic elaboration and recency judgments in children

Recency judgments in second and fourth grade Ss were examined when contextual or spatial locations were correlated with sequential order. No age differences were apparent when the cues were not available; however, unlike fourth grade Ss, the younger Ss failed to take advantage of the additional cues when they were provided. In Experiment 2, second grade Ss were successfully trained to use the appropriate strategy, suggesting that the age related deficiency was one of production rather than mediation. The effectiveness of mnemonic elaboration as an aid to recall of order information was established, together with the short-term efficiency of training such mnemonic strategies in young children who do not adopt them spontaneously. The data support the hypothesis that memory tasks are developmentally sensitive when a deliberate mnemonic strategy can be applied but insensitive to developmental differences when no strategy is appropriate.     

Some determinants of behavioral contrast in pigeons and rats

In Expt. 1, pigeons trained on a multiple variable interval, extinction schedule, showed a positive contrast effect by comparison with control groups trained with S+ only, provided that the interval between stimulus presentations was short (10 sec), but not when it was long (60 sec). Positive contrast also occurred more readily with an easier discrimination, and its appearance was highly correlated with the temporary appearance of transient contrast effects. Although a longer interval between trials produced an overall increase in rate of responding in subjects trained only with S+, it was suggested that this at best represented a different type of contrast effect. In Expt. 2, rats showed positive contrast to S+ when S− was correlated with a lower frequency of reinforcement, but not when it was correlated with a reduced magnitude of reinforcement. The results were discussed in terms of frustration theory.     

The effects of perceptual pretraining on concept identification and preference

The effects of perceptual pretraining on preferences and concept identification performance in five- and eight-year-old Ss were investigated. The results indicated that perceptual pretraining facilitated performance on a concept identification task with a non-preferred relevant cue for the five-year-olds, but not for the eight-year-olds. However, perceptual pretraining did not affect preference in either age group and Ss were as consistent in their preference responding before and after perceptual pretraining as was a control group that had not received perceptual pretraining. Preferences were highly consistent in both age groups over a one week period. Perceptual pretraining was interpreted to increase the usability of the less preferred dimensions for the younger Ss, and to leave the affective preference response unaltered in both groups.     

A judgement analysis of social perceptions of attitudes and ability

A judgement analysis of people's social inferences of attitudes and ability was conducted. University students were asked to infer the liberalness (N = 60; Study 1) or intelligence (N = 40; Study 2) of targets seen in pictures. Multiple regression analyses revealed that attractiveness was the most important cue for predicting inferences of liberalness, while an ethnic cue (i.e., being Asian) was the most important cue for judgements about intelligence. Results also showed that a single-cue model was less susceptible to overfitting, but significantly less accurate than a multiple-cue model in predicting participant's intelligence judgements. Although the multiple regression models suffered a degree of overfitting, cross validation showed that they continued to have significant predictive value when applied to new data. Furthermore, a “random partner” method (comparing each participant's own regression equation with that of another, randomly selected, participant) provided evidence of significant idiosyncratic variation in the way intelligence judgements were made.     

Optional shift behavior as a function of age and dimensional dominance

An optional reversal-nonreversal shift task for which the relevant color or form cues were either dominant or nondominant was presented to 320 Ss, 6 through 20 years of age. Dominance, as defined in terms of relative cue similarity, was related to initial learning and shift behavior for kindergarten and third-grade Ss; but not for sixth-grade and college Ss. The speed of initial learning and percentage of reversal shifts was related to age when the nondominant dimension was relevant. There were no developmental differences when the dominant dimension was relevant.     

Informational and motivational components of social reinforcement

Thirty-six four-year-old children of each sex were tested in a two-choice marble dropping task. There were three Ss in each cell of a 3 × 2 × 2 × 2 factorial design. The factors investigated were: reinforcement condition (Contingent, Yoked, Nonreinforcement), sex, base preference level (strong vs weak), Base Rate Level (high vs low). The dependent variables were: base preference ratio, base rate, preference ratio change, rate change. The contingently reinforced Ss had significantly higher preference change scores than Ss in the other two reinforcement conditions but only at the high base preference level. The Ss in both the contingent and yoked groups had higher rate change scores than Ss in the nonreinforcement group. The results were interpreted as indicating social reinforcement may have two effects, one a cue function and the other an effect on S's motivational system. The results indicate that regression effects do not operate in the two-choice task and that crossing baseline levels of performance is an effective way to control baseline differences in analyses of change in the two-choice task.     

Facilitation versus inhibition in non-spatial attribute discrimination tasks

Inhibition of Return is a delay in initiating attentional shifts to previously inspected locations. It has been explained as a mechanism to facilitate visual search of a scene by inhibiting the allocation of attention to locations that have already been examined. We (Hu, Samuel, &; Chan, Journal of Experimental Psychology: General, 2010) recently demonstrated that similar processing costs can appear when a non-spatial attribute (color or shape) repeats—detection of a target stimulus was slower if the target shared color or shape with a recently presented cue. In the current study, we test whether such inhibitory effects occur for non-spatial attribute repetition when observers must make a discrimination judgment about targets. We found two independent effects: First, there was a standard location-based IOR effect—target discrimination was slower when the target appeared in the same location as a preceding cue. Second, reaction times were faster if the target's color or shape matched the cue's color or shape; this facilitation effect contrasts with both the location-based inhibition that was present in the current experiments, and with the inhibitory effect of feature repetition in our previous detection task study. The data are best accounted for by a three-factor model recently suggested by Lupiáñez (Attention and time, 2010).     

The Rabkin Test as a Means of Detecting and Analyzing Defective Color Vision

This study investigated the attentional and mental-set conditions which determine the acquisition and use of memory schema cues. Ninety male and female undergraduate Ss listened to and shadowed the Bransford-Johnson “washing clothes” paragraph under a variety of conditions defined by cue placement (before or during shadowing), attentional mental set (told of relation of cue to passage, or not told), and modality of cue (given visually or auditorily). It was found that cue placement and cue modality had no effect on subsequent recall of the passage, but that attentional mental set did. It was argued that the data supported a model of the mind that emphasized conscious intention in both attention and schema activation, a position associated with Wilhelm Wundt.     

The predictive validity of a vocational interest inventory-“Ramak”: Seven year follow-up

The purpose of this study was to test the predictive validity of the Ramak-a vocational interest inventory based on Roe's (1956) classification of occupations. In this follow-up, 81% of the original sample, tested 7 yr earlier, was located. These Ss responded to a questionnaire which inquired into their vocational choice and vocational choice satisfaction, together with retesting of the Ramak. Results showed that: (a) The median interpersonal test-retest reliability was .412 for males and .401 for females, while the median within-the-person profile stability was .535 for males and .700 for females; (b) With few deviations, for each occupational field the Ss occupied in that field had the highest interest in that field; (c) With the exception of Arts and Entertainment in both sexes, for each interest field Ss who had the highest score were those engaged in that field; (d) The correlation between vocational choice satisfaction and the interests in the relevant field was .405 and .294 for males and females, respectively; (e) For both sexes, Ss occupied in their highest-scoring interest field were more satisfied with their vocational choice than those who were not. The effectiveness of the Ramak in vocational counseling is evaluated.     

Maintenance rehearsal affects knowing,not remembering; elaborative rehearsal affects remembering,not knowing

In a directed-forgetting paradigm, each word in a study list was followed by a cue designating that word as eitherlearn orforget. This cue appeared after either a short or a long delay. It was assumed that a long delay would increase maintenance rehearsal of all the words, and that only the words followed by a learn cue would be rehearsed elaboratively. Moreover, because the interval between the words was constant, a short cue delay should allow more time for elaborative rehearsal. In a subsequent test, subjects maderemember orknow responses to indicate whether recognition of each word was accompanied by conscious recollection or by feelings of familiarity in the absence of conscious recollection. The hypothesis was that remembering depends on elaborative rehearsal, and knowing depends on maintenance rehearsal. In accord with this hypothesis, the learn-versus-forget designation influenced remember but not know responses, and there were more remember responses after the short cue delay; cue delay influenced know responses, regardless of word designation.     

Stimulus generalization and the response-reinforcement contingency

Generalization gradients along a line-tilt continuum were obtained from groups of pigeons that had been trained to peck a key on different schedules of reinforcement. In Exp. I, gradients following training on a differential-reinforcement-of-low-rate (DRL) schedule proved to be much flatter than gradients following the usual 1-min variable interval (VI) training. In Exp. II, the value of the VI schedule itself was parametrically studied; Ss trained on long VI schedules (e.g., 4-min) produced much flatter gradients than Ss trained on short VI schedules (30-sec; 1-min). The results were interpreted mainly in terms of the relative control exerted by internal, proprioceptive cues on the different reinforcement schedules. Several implications of the results for other problems in the field of stimulus generalization are discussed.     

Finite automata and S−R models

Suppes (1969, Journal of Mathematical Psychology, 6) apparently proved that any finite automaton could be mimicked by the asymptotic behavior of a stimulussampling S?R model, broadly implying that cognitive theory could be reduced to S?R theory. Here it is shown that the finite automata used by Suppes are more restricted and less powerful than finite automata in general. Furthermore, the S?R models proposed by Suppes are limited to producing the behavior of only these restricted automata, and cannot mimic all finite automata. Hence, the formal claim that S?R models are adequate to produce all behaviors obtainable from finite automata, and the informal claim that cognitive theory reduces to S?R theory, do not follow from Suppes's (1969) result. Some alternative S?R models and their problems are also briefly discussed.     

Inhibition and language pragmatic view in redundant data problem solving

The present study concerns redundant data problems, defined as problems in which irrelevant data is provided. This type of problem provides a misleading context [Pascual-Leone, J. (1987). Organismic process for neo-Piagetian theories: A dialectical causal account of cognitive development. International Journal of Psychology, 22, 531–570] similar to the Piagetian class inclusion task. The two experiments performed showed that adding the a-pragmatic cue ‘in total’ to the final question of redundant data problems increased both 7- and 9-year-old children's failure rate, without modifying the structure of the problem. This indicates that a non-structural linguistic cue can bias children towards failure by enhancing the lack of inhibition of the ordinary adding schema.     

Subjective estimates of shock probability following classical aversive conditioning with visual and gustatory conditioned stimuli

In two recent studies (Evans and Busch, 1974; Busch and Evans, in press) designed to explore the relevance of “cue appropriateness” concepts to aversion therapy, it was found that taste was a less effective CS than color. The major limitations of these studies were that conditioning was inferred from subjective ratings (although cross-validated by an unobtrusive but equally inferential performance measure), and the taste stimuli were rated more negatively in the pre-test than the color stimuli, thus creating possible ceiling effects.Quite apart from limitations in these particular studies, almost all cue appropriateness research contains methodological flaws; obvious ones are the failure to equate stimuli in different sense modalities for subjective intensity, or salience, and the failure to equate the ISIs when visual and gustatory elements of ingestible substances are the cues of interest. One of our studies (Busch and Evans, in press) partially resolved the timing problem, but in studies of visually-oriented college students the salience problem remains acute. It therefore seemed worthwhile to investigate whether, in the paradigm used in our laboratory, subjects simply attend less to taste cues than to color cues.In order to determine cue salience, a measure other than the development of CRs must be used. If an organism comes to give a CR to a certain stimulus, that is prima facie evidence of attention to, or if one prefers it, reception of, that stimulus, although generalization studies show the elements of the stimulus actually controlling the CR may not necessarily be the ones expected by the experimenter. Animal conditioning studies have shown, however, that the failure of CRs to emerge does not inevitably mean that the stimulus was ignored and an appropriate CR may appear if performance-related variables are manipulated. Similarly, humans may or may not show a CR and yet be able to verbalize correctly the contingency experienced during the conditioning. Thus for human Ss a cognitive expectancy measure should be able to reveal cue salience independent of the actual elaboration of a CR. We therefore repeated the Evans and Busch (1974) procedure and measured, instead of attitudinal changes to the CS, the Ss' perception of the contingency they had experienced.     

Positive contrast obtained in reacquisition following interpolation of nonreinforced or partially reinforced trials

Two experiments investigated the effects of shifting from either nonreinforcement or partial reinforcement (PRF) to continuous reinforcement conditions (CRF). In the first experiment, three groups of rats were given food reinforcement under CRF conditions in a runway followed by regular extinction trials (RE), extinction trials where Ss were delayed for 30 sec before entering the empty goal box (DE), or CRF trials where Ss were delayed for 30 sec before entering the baited goal box (DF). Then all Ss were run on the delayed reinforcement condition (DF). In the final delayed reinforcement condition, group DE ran significantly faster than group DF, reflecting positive contrast. In the second experiment, four groups of rats were trained in a runway to receive either 4% or 18% sucrose reinforcers under either PRF or CRF conditions. Then all Ss were transferred to a Skinner box and bar presses were continuously reinforced, with each S continuing to receive the same sucrose concentration as before. The former PRF Ss, regardless of the reinforcer, bar pressed at a significantly higher rate in the Skinner box than the former CRF Ss. The evidence seemed to favor the view that the effectiveness of a reinforcer is not an absolute, unchanging quantity but rather depends on the historical context in which the reinforcer occurs.     

The assessment of subjective probability distributions: A training experiment

For this experiment 22 Ss were especially trained to assess subjective probability distributions for proportions concerning student characteristics. Two different assessment techniques were used. There were four experimental sessions. From the second session on, Ss received feedback about their performance in the previous session(s). While Ss' associated by far too much confidence with their assessments at the beginning, they learned to assess more realistic distributions. Furthermore, discrepancies between techniques were reduced.Some considerations for a more effective training procedure are made and the concept of giving feedback only according to the tightness of the assessed distribution is critically discussed.     

Effects of Specific Cue Content on Need for Achievement Scores

Based on the hypothesis that cue content of need for achievement tests can influence scores on these tests because of the cue's specific past associations for the Ss, a study was conducted with special cues and selected Ss to discover differences which might ordinarily be masked. The Ss were 14 male undergraduate swimmers and 14 male undergraduate musicians from the University of Michigan. They were given a French (1955) type need for achievement test. The results of the study indicate that cue content is important, but only under rather specific conditions. The implications of the findings for interpretation of n Ach scores in general are discussed.