Does recognition memory improve with age?

In order to test the hypothesis that recognition is a developmentally stable component of the memory system, age differences in recognition of faces were examined while controlling for nonmemory factors that might contribute to differences between the groups. Three groups of children (mean ages: 3 years, 4 months; 4 years, 9 months; and 6 years, 11 months) and a group of college students were tested on a recognition task and a similar matching task. The results indicated no change in recognition across the preschool years but an improvement from the later preschool period to the first grade. Further analyses indicated that this improvement was not due to changes in decision criteria or perceptual skills. These findings call into question the view that recognition is a developmentally invariant component of the memory system.     

Self-consciousness, outcome expectancy, and persistence

A study investigated persistence as a function of two variables: the disposition to be self-attentive (called private self-consciousness) and outcome feedback on a prior task that was described as closely related to the target task. More specifically, subjects first completed a concealed-figures test and were told that their performances were either very good or very poor. The second test, which ostensibly measured the same abilities, was an insolvable design problem that is commonly used to measure persistence. Feedback concerning prior outcomes had a direct influence on expectancies for the second task, but persistence on that task was a joint function of feedback and self-consciousness. That is, favorable feedback led to greater persistence than did unfavorable feedback, but only among subjects high in self-consciousness. This finding replicates and extends the results of several previous studies. Discussion centers on the relationship between the present research and an earlier experiment which yielded apparently different results.     

Learning to program in LISP

We have gathered protocols of subjects in their first 30 hours of learning LISP. The processes by which subjects write LISP functions to meet problem specifications has been modeled in a simulation program called GRAPES (Goal Restricted Production System). The GRAPES system embodies the goal-restricted architecture for production systems as specified in the ACT* theory (Anderson, 1983). We compare our simulation to human protocols on a number of problems. GRAPES simulates the top-down, depth-first flow of control exhibited by subjects and produces code very similar to subject code. Special attention is given to modeling student solutions by analogy, how students learn from doing, and how failures of working memory affect the course of problem-solving. Of major concern is the process by which GRAPES compiles operators in solving one problem to facilitate the solution of later problems.     

A partial resolution of the paradox of interference: The role of integrating knowledge

It has been noted that models of memory that posit retrieval interference imply that the more one knows about a topic, the harder it is to retrieve any one of these facts. Smith, Adams, and Schorr (Cognitive Psychology, 1978, 10, 438–464) regard this to be a paradox and postulate that people use world knowledge to integrate various facts about a concept and thereby avoid interference. Exploring this issue further in two experiments we discovered that integration of facts alleviates interference only when a person can perform his memory task by simply making a consistency judgment and can avoid the need to retrieve a specific fact. When foils force subjects to retrieve the specific assertion, the interference occurs among integrated facts as among unrelated facts. It appears that, when possible, subjects will judge whether they have seen a fact simply by judging if it is related to (consistent with) a theme they have studied. In other words, people judge themes rather than facts. Consistent with this interpretation, we found interference among themes; that is, the more themes were associated with a concept, the greater the interference.     

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.     

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.     

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.     

A learning algorithm for boltzmann machines

The computational power of massively parallel networks of simple processing elements resides in the communication bandwidth provided by the hardware connections between elements. These connections can allow a significant fraction of the knowledge of the system to be applied to an instance of a problem in a very short time. One kind of computation for which massively parallel networks appear to be well suited is large constraint satisfaction searches, but to use the connections efficiently two conditions must be met: First, a search technique that is suitable for parallel networks must be found. Second, there must be some way of choosing internal representations which allow the preexisting hardware connections to be used efficiently for encoding the constraints in the domain being searched. We describe a general parallel search method, based on statistical mechanics, and we show how it leads to a general learning rule for modifying the connection strengths so as to incorporate knowledge about a task domain in an efficient way. We describe some simple examples in which the learning algorithm creates internal representations that are demonstrably the most efficient way of using the preexisting connectivity structure.     

Infants' search for visible objects: implications for the interpretation of early search errors

This study examined the error patterns of 9-month-old infants searching for hidden objects and objects that were visible within a container. Although errors occurred in both conditions, there were important differences between them. When the object was hidden, infants showed significant perseveration in that they searched more often at the object's previous hiding place than at a control location. When the object was visible, however, they made fewer errors and the errors they did make were as likely to be to the control location as to the previous hiding place. These results suggest that infants' errors in searching for a visible object reflect lapses of attention rather than systematic misunderstandings of objects or space and so are not incompatible with an information-processing account of early search.     

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.     

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.     

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.     

The development of children's problem solving in a gears task: A problem space perspective

I examined two contexts of development in children's problem solving: (1) the macro-context of different age cohorts (8–9 vs 11–12 years of age); and (2) the micro-context of an approximately one-hour experimental session. Twenty subjects (even divided across sexes and these two age groups) were individually presented a collection of variously sized gears, a board onto which these gears could be easily attached and rotated, and a knob. Each subject was asked to find all solutions, in which two marked gears were turning the same way, and to represent these solutions graphically. Subjects applied four different problem spaces to the task: the Euclidean, the Kinematic, the Dynamic, and the Topological. The Arithmetic Modifier could be applied to any of these problem spaces, resulting in a numerical characterization of the gear constructions and/or production strategies. The 11–12's tended to shift problem spaces adaptively; the 8–9's seldom did so. Analysis of the pathways of transition between the problem spaces revealed a complex picture of partial or complete incorporation, and substitution.     

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.     

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.     

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.