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.     

Self-directed attention and the comparison of self with standards

Several theorists have assumed that self-directed attention causes a comparison between one's present behavior or state and whatever is salient and relevant as a standard of comparison. Indirect evidence bearing on this assumption was gathered in a series of four studies by monitoring subjects' tendencies to access concrete information needed to make such behavior-standard comparisons. Self-focus was varied in two of these studies by experimental manipulations: a mirrored surface, and a live observer. In the other two studies, self-focus was operationalized in terms of subjects' dispositional tendencies to direct attention to themselves (self-consciousness). Consistent with expectations, in Experiments 1 and 2, self-directed attention led to increased frequency of referring to drawings of geometric figures when attempting to reproduce them. In Experiments 3 and 4, self-focused attention increased subjects' tendencies to seek out information about ostensible performance norms reflecting the behavior of other subjects, also as predicted.     

Self-consciousness,self-report of aggressiveness,and aggression

Private self-consciousness consists of attending to one's thoughts, feelings, and motives. Public self-consciousness consists of attending to oneself as a social object. The effect of dispositional self-consciousness on the accuracy of self-reports was studied in research on aggression. High- and low-private self-conscious subjects rated their own aggressiveness. Several weeks later their aggressive behavior was objectively measured. The correlation between self-report of aggressiveness and aggressive behavior was significantly higher for high-than for low-private self-conscious subjects. The correlation between self-report and behavior was unaffected by public self-consciousness. The implications of these findings for self-consciousness theory and personality dispositions are discussed.     

Eye fixations and cognitive processes

This paper presents a theoretical account of the sequence and duration of eye fixation during a number of simple cognitive tasks, such as mental rotation, sentence verification, and quantitative comparison. In each case, the eye fixation behavior is linked to a processing model for the task by assuming that the eye fixates the referent of the symbol being operated on.     

Self-consciousness, self-awareness, and self-attribution

Self-awareness was either manipulated by a mirror (experimental) or not (control). Subjects were selected for being high or low in private self-consciousness (disposition to attend to one's thoughts, feelings, motives). Private self-consciousness had a stronger effect on self-attributions than did self-awareness. These findings have implications for attribution, self-consciousness, and the relationship between manipulations and dispositions.     

The functional equivalence of problem solving skills

The tower of Hanoi problem is used to show that, even in simple problem environments, numerous distinct solution strategies are available, and different subjects may learn different strategies. Four major classes of solution strategies are described for the problem. Different strategies have different degrees of transferability, place different burdens on short-term memory and on perception, and require different learning processes for their acquisition. The analysis underscores the importance of subject-by-subject analysis of “what is learned” in understanding human behavior in problem-solving situations, and provides a technique for describing subjects' task performance programs in detail.     

Defining the locus of developmental differences in children's causal reasoning

Five experiments were performed in the area of children's causal reasoning to validate a previously reported developmental difference, to examine the role of a possible mediating mechanism, and to test a number of competing theoretical interpretations. As previously, the regularity of a cause-effect pairing influenced the causal attributions of 8- and 9-year-olds but not of 5- and 6-year olds; the results were found not to be artifacts of either a response induced commitment to choosing a particular object or the brevity of the exposure period. The developmental difference also was not explained by discrepant encoding of the term “cause,” by memorial deficiencies, or by differences in criteria for drawing causal inferences. Instead, it appeared that greater perceptual distractibility prevented the younger children from searching for and finding the temporally invariant relationship hypothesized to be crucial to inferring causality in the experimental situation.     

Modeling strategy shifts in a problem-solving task

A computer simulation model was fitted to human laboratory data for the Missionaries and Cannibals task to explain (1) the effects upon problem performance of giving a hint, and (2) the effects of solving the problem a second time after one successful solution had been achieved. Most of the variance in the relative frequencies of different moves can be explained by positing that the effect of the hint, or of previous experience in solving the problem, is to cause subjects to switch more promptly from a strategy of balancing the numbers of missionaries and cannibals on both sides of the river, to a means-ends strategy.     

Three aspects of cognitive development

An attempt was made to characterize and explain developmental differences in children's thinking, specifically in their understanding of balance scale problems. Such differences were sought in three domains: existing knowledge about the problems, ability to acquire new information about them, and process-level differences underlying developmental changes in the first two areas. In Experiment 1, four models of rules that might govern children's performance on balance scale problems were proposed. The rules proved to accurately describe individual performance and also to accurately predict developmental trends on different types of balance scale problems. Experiment 2 examined responsiveness to experience; it was found that older and younger children, equated for initial performance on balance scale problems, derived different benefits from identical experience. Experiment 3 examined a potential cause of this discrepancy, that younger children might be less able than older ones to benefit from experience because their encoding of stimuli was less adequate. Independent assessment procedures revealed that the predicted differences in older and younger children's encoding were present; it was also found that these differences were not artifactual and that reducing them also reduced the previously observed differences in responsiveness to experience. It was concluded, therefore, that the encoding hypothesis explained a large part of the developmental difference in ability to acquire new information.     

A test of parallel versus serial processing applied to memory retrieval

Townsend has identified necessary and sufficient conditions that reaction time distributions meet if they are produced by two underlying processes that are parallel and within-stage independent. This paper describes an attempt to use one of these conditions to assess the assumption of independent parallel memory retrieval in Anderson's ACT theory. In the experimental test, subjects studied profession-location pairs, with each profession and location included in two pairs. One pair had a high frequency of presentation and the other had low. When cued with a profession (or location), subjects responded with the first of the two studied locations (or professions) that came to mind. The reaction times to these responses were used to test the ACT assumption of independent parallel search. The problems encountered in trying to apply Townsend's abstract test to a concrete situation included the need to consider mixtures and convolutions of distributions and empirical, rather than theoretical, distributions. These difficulties are discussed at length and some formal analyses concerning their effect on the test are given. Despite these problems, we were able to use Townsend's test and the results of the experiment support the within-stage independent parallel assumption of ACT.     

Identifying the relevant aspects of a problem text

Forty-nine subjects judged the relevancy of sentence parts of a word problem (the Allsports problem). Patterns of subjects' judgments suggest three problem-solving heuristics: a SETS heuristic, a TIME heuristic, and a QUESTION heuristic. Presentation of the question before the problem tends to suppress SETS and TIME heuristics. A computer program (ATTEND) is presented to simulate subjects' behavior on the Allsports problem. The program is context-sensitive in that it can change a relevance judgment upon the acquisition of further information. Averaged subject judgments and ATTEND judgments agree for 87% of the items.     

Comprehending quantified sentences: The relation between sentence-picture and semantic memory verification

People were timed as they decided whether quantified sentences like All (some) of the round figures are red were true or false of an accompanying picture. The response latency was a function of the quantifier and the relation between the sets mentioned in the subject and predicate of the sentence. The pattern of latencies was similar to the pattern found for sentences that refer to concepts in semantic memory, e.g., All (some) dogs are animals (Meyer, 1970). This result suggests that the same process may be operating in both domains. Two alternative models of the process are considered. One model assumes that the common process consists of computing the relation between the two sets mentioned in the sentence. The other model assumes that the common process consists of comparing the representation of the sentence to the representation of information computed from the second source. Both models are integrated with broader theories of performance in various comprehension tasks.     

Span and rate of apprehension in children and adults.

Children and adults quantified random patterns of dots, under unlimited exposure duration. For adults and children two distinct processes appear to operate. For adults the quantification of collections of from one to three dots is essentially errorless, and proceeds at the rate of 46 msec per item, while the quantification rate for from 4 to 10 dots is 307 msec per dot. For children the same operating ranges appear to hold, however children are much slower. The lower slope is 195 msec per dot, while the upper is 1049. Although the results for adults and children are similar except for the overall rates, the nature of the isomorphism between children and adults is unclear.     

The role of elaborations in memory for prose

In two experiments, subjects read stories and were asked to make plausibility judgments about statements with respect to the stories. The inherent plausibility of the queried statements, the amount of attention subjects focused on information necessary for making a judgment, and the interval between presentation of the relevant story information and the test probe were varied orthogonally. The pattern of latencies obtained to make these judgments cast strong doubt on the notion that question answering is typically accomplished by searching for a single fact in memory. Rather, people seem to retrieve any relevant, available information and then use this to compute whether a statement seems true. The independent variables in these experiments can be interpreted according to whether they affect the retrieval or the judgment phase.     

Self-focused attention and reactions to fear

Two studies were conducted to study the effect of self-focused attention on behavioral responses to fear. In Experiment 1, phobics and nonphobics were asked to approach and hold a snake either in the presence of a mirror or with no mirror. In Experiment 2, high and low private self-conscious subjects were asked to submit to a series of either mild or strong electric shock for humanitarian reasons. In each case, self-directed attention caused increased responsivity to the fearful affect and made subjects more likely to withdraw from the situation, regardless of the fact that a behavioral standard existed which called for an opposite response. The theoretical and behavioral implications of the findings were discussed.     

Developments in infants' search for displaced objects

In an exploratory study of infants' search for displaced objects, 13-month-olds and 21-month-olds were tested on three kinds of displacement problems—visible displacements, invisible displacements, and transpositions—as well as singlehiding problems. Two aspects of performance on the displacement problems were distinguished: (1) searching within the locations involved in the displacement rather than at a control location, and (2) selecting between the displacement locations. Both the younger and the older infants were able to select the correct location on visible displacement problems and to search within the displacement locations on invisible problems. Neither age group was able to solve the transposition problems, but the older infants did at least search within the relevant locations on those problems. Age differences appeared to be due primarily to improved skill at identifying relevant locations rather than to improvements in selecting among those locations. Other factors contributing to the age differences in performance were a decrease in response biases and an increase in skills for coping with multiple possibilities.     

Texture gradient registration and the development of slant perception.

The processes underlying the development of slant perception were investigated by manipulating the degree of texture element variability. Subjects at four grade levels were required to make judgments of physical slant of surfaces with three levels of variability. Absolute error of judgment decreased with age, but texture variability had no effect at any grade level. The results suggest that there is no improvement in the ability to extract gradient information. Rather, improvement in the consistency of judgment reflects a developmental change in the relationship between stimulus information and judgment.     

Comparison of two oddity tasks with pigeons

Two oddity tasks were compared: one in which the odd stimulus could appear on any of the three stimulus positions (true oddity); the other in which the odd stimulus could only appear on the left or right but not the center (oddity-from-sample). A stimulus-configuration theory predicts faster oddity-from-sample learning, whereas a theory, based on shifts in observing over trials, predicts faster learning of true oddity. Pigeons learned the oddity-from-sample task faster, thus supporting configuration theory. Performance on the oddity-from-sample task but not the true oddity task was facilitated by increasing the number of responses required to terminate a trial. When the oddity-from-sample pigeons were shifted to the true oddity task, no evidence of positive transfer was found, suggesting that a configuration theory alone is insufficient to explain differences in acquisition. Only when a correction procedure was introduced did the true oddity pigeons perform above 50%.