Short-term memory and information processing in pigeons

Six pigeons were trained to asymptotic performance on a variable-delay matching-to-sample task in which the samples were sometimes line or color elements and sometimes line-color compounds. On compound-sample trials, the comparison stimuli were sometimes color elements and sometimes line-tilts. Sample type and delay (0, 1.5, and 4.5 sec) were varied within sessions, and sample duration (.4, 1.0, and 3.0 sec) was varied between sessions. Forgetting curves were steeper for line-tilt than for color. As sample duration increased, matching performance improved more for colors than for line-tilts, especially at delays greater than zero. Performance was better with element samples than with compound samples only on the line-tilt dimension at zero delay. Some predictions of a unitary trace growth and decay theory of pigeon short-term memory were not confirmed. A dual-code hypothesis was proposed to account for the data.     

The interaction of memories in the rat: Effects on short-term retention performance

In four experiments, rats were tested for short-term retention of a target spatial location either with or without prior exposures to alternate spatial locations in a T-maze. In all cases, exposure to alternate locations prior to exposure to the target location impaired retention of the target. This impairment increased as the number of exposures to the alternate location was increased, and the impairment decreased as the interval between alternate and target exposures was increased. In no case was the magnitude of the impairment found to increase as the retention interval was lengthened.     

The psychological causality implicit in language

We are concerned with the causality implicit in English verbs that name interactions, either mental or behavioral, between two persons, verbs such as like, notice (mental), and help, cheat (behavioral) in such a context as Ted—Paul. Using four different methods, we show that adult native speakers think of causality in such verbs as unequally apportioned between interactants. For behavioral (or action) verbs greater causal weight is given to the Agent argument of the verb (e.g., Ted in Ted helps Paul) than to the Patient argument (Paul). For mental (or state) verbs greater causal weight is given to the Stimulus argument of the verb (e.g., Paul in Ted likes Paul) than to the Experiencer argument (Ted). For English verbs of the type studied, derivational adjectives often exist (e.g., helpful, cheating, likable, noticeable). Such adjectives are attributive to one or the other argument of the verb base (Agent or Patient; Stimulus or Experiencer). We show that the direction of causal attribution in the adjective (e.g., helpful is attributive to Ted the Agent; likable is attributive to Paul the Stimulus) predicts the primary causal weightings assigned in our experimental tasks. We also show that in the English language adjectives derived from action verbs are almost attributive to the Agent and adjectives derived from state verbs to the Stimulus. Because certain facts about English morphology predict certain ways of thinking about causality, our main finding may seem to be a Whorfian one, a demonstration that language affects thought. However, we argue that it is not that but rather a demonstration that two modes of thought (the Agent-Patient Schema and the Stimulus-Experiencer Schema) affect language use. We suggest that the schemas are universals of human thought.     

A mathematical analysis of a natural class of partitions of a graph

Any finite graph (nondirected, no loops) can be coupled with its complementary graph producing what we term a completed graph. This paper studies completed graphs in the context of a structural concept called stratification that is motivated by theoretical work in social psychology and sociology. A completed graph is stratified in case its node (vertex) set can be divided into two nonempty subsets with exactly one of the two types of ties holding between every pair of nodes from distinct sets. A completed graph is totally stratified in case every one of its nontrivial completed subgraphs is stratified. The first part of the paper relates the concept of stratification to the familiar graph property of connectedness. In particular, a completed graph is totally stratified if and only if it does not have a four point completed subgraph that is connected in both the original graph relation and its complementary relation. Using the concept of stratification, completed graphs can be decomposed uniquely into taxonomic structures, that is, nested sets of partitions. An algorithm for the decomposition based on the work with the concept of stratification is developed. The relationship between the notion of stratification and the ideas in balance theory is examined, and stratification is viewed as a generalization of Davis' notion of clustering. It turns out that the concepts of clique, status, and structural equivalence used throughout the social networks literature can be defined in an interesting way for completed graphs. Cliques are sets of nodes with similar internal links and statuses are sets of nodes with similar external links. Structurally equivalent sets are both cliques and statuses. The concepts of status and structural equivalence are closely related to the decomposition algorithm. In particular, for any totally stratified completed graph, the set of all statuses and the set of all maximal structurally equivalent sets can be generated by mathematical operations performed on the taxonomic decomposition of the completed graph. Finally some of our resuls are informally related to the blockmodeling approach to analyzing social network data discussed in several previous Journal of Mathematical Psychology articles.     

Experiences that motivate moral development: The role of cognitive dissonance

It has been found in previous research concerning Kohlberg's stages of moral development that engagement in a “real-life” moral dilemma sometimes leads to an advance in an individual's level of moral thought. It is argued in this study that such moral growth is often motivated by the need to reduce cognitive dissonance, which, it is suggested, frequently accompanies choice and commitment in moral contexts. Subjects in the present study delivered counterattitudinal messages that contained arguments that were either 1 stage higher or 1 stage lower than their characteristic level of moral reasoning. Half of the subjects freely chose to deliver these messages, and half did not. Afterwards, subjects' attitudes toward the issues discussed in their messages and their tendency to conceptualize moral issues in terms of the higher or lower levels of reasoning contained in their messages were assessed. The subjects who (a) had freely chosen to deliver the message, and (b) had delivered the message containing higher level arguments used significantly more advanced moral reasoning after their counterattitudinal advocacy than they had before it. These subjects showed greater change in their attitudes regarding the topic discussed in their message than other subject groups. These results suggest that moral behavior will be likely to promote moral growth (a) if it occurs under circumstances that promote cognitive dissonance (e.g., free choice) and (b) if advanced moral ideas are made salient during the dissonance reduction process.     

A factor analytic validation of Holland's Vocational Preference Inventory

A principal components analysis was applied to a 135-item pool of the Holland Vocational Preference Inventory, Sixth Revision. The sample consisted of a cross section of 100 men and 200 women college students under the age of 25 yr. An eight-factor structure was defined for each of the sexes which is discussed in relation to Holland's clinically based scales, sex differences and criterion groups as defined by choice of major subject. The a priori clinical scales were partially upheld with differences attributed to the characteristics of the sample and sociopolitical time context during which the test was administered. A new scale emerged relating to an interest in professions involving law and politics.     

Paired-associate learning by normal children and retardates with relevant redundant compound stimuli

During daily sessions four first-grade boys each played a two-choice marble dropping game. When one colored light was presented a plain token was dispensed as soon as S dropped a marble, and when another light was on a token with a hole in its center was delivered. During choice trials that were interspersed among single-color trials S had to choose one of the two different colored holes. At the end of each session S traded tokens with holes for pennies and then turned in the remaining plain tokens which were not exchanged for money. After S had developed a preference for the response that earned the tokens with holes (tokens that were backed up with pennies) E instructed S to try to get as many plain tokens (unexchangeable tokens) as he could. All Ss immediately switched to the response that earned unexchangeable tokens but as soon as E left they returned to choosing the backed up response. When the adult reentered, Ss again chose to work for unexchangeable tokens. Two different Es (male and female) served and the instructions of each were effective in controlling responding as long as the adult was present, except for one S who did not respond to one E, but did respond as described for the other.     

Acquisition of spatial antonym pairs

Twenty-eight children (mean age 4.3 yr) were tested for comprehension of spatial antonym pairs with arrays which contained four objects representing both members of two antonym pairs. The results showed that: (a) the most common error was to point to an object representing the same polarity (marked-unmarked) as the word requested; (b) there was not a high degree of confusion within antonym paris; (c) unmarked antonyms tend to be acquired before marked antonyms; and (d) the order of acquisition of the pairs was: tall-short, long-short, high-low, thick-thin, deep-shallow, wide-narrow. The results were interpreted as supporting a modified semantic-feature hypothesis, in which polarity is acquired before dimension.     

Constraints on the processing of indirect speech acts: evidence from aphasiology

The ability of anterior aphasics and patients with right-hemisphere damage to comprehend both the literal and nonliteral readings of indirect speech acts was examined. Subjects viewed videotaped episodes in which one actor asked another “Can you X?” and the second actor responded with either an action or a simple “Yes.” Subjects judged whether the response was appropriate given its context. Anterior aphasics could comprehend the nonliteral but not the literal reading, supporting models that posit that people have direct access to nonliteral but conventional readings. Patients with right-hemisphere damage could appreciate the direct reading, but failed to distinguish between appropriate and inappropriate action-responses. This finding suggests that it may be possible to dissociate the pragmatic and syntactic aspects of comprehension of indirect speech acts.