Kindergarten children's use of category membership

Kindergarten children (N = 70) learned to order 12 photographically presented objects. The objects were well known and either unrelated or categorizable into two, three, four, or six well-known categories. Free recall was assessed. Results indicated that the children used category membership both to learn and to recall the items. However, they processed the list composed of six pairs of items at least as efficiently as lists composed of fewer but larger groups of items (including a list indexed as easiest through previous adult performance).     

Contingent reinforcement of lowered blood-alcohol levels in an outpatient chronic alcoholic

Recently. the proposition that alcohol abuse is an operant behavior and thus functionally related to its consequences has been investigated under experimental conditions. In controlled laboratory settings, in which inpatient chronic alcoholics are allowed access to alcoholic beverages, alcohol consumption has been markedly altered via operant strategies. Monetary rewards (Cohen et al., 1971), the opportunity to participate in an enriched environment (Cohen et al., 1971). and visits to a girlfriend (Bigelow et al., 1973) have been used as reinforcers for decreased drinking.Other investigators (Sulzer, 1965; Miller, 1972: Hunt and Azrin, 1973) have successfully applied similar contingency management techniques to alcoholics in the natural environment. However, failure to control for the influence of extraneous therapeutic variables (e.g., attention-placebo factors, job counseling) together with reliance on self-report measures of drinking behavior seriously limit the conclusiveness of these results. Objective assessment is particularly essential with operant techniques since consequent events must be systematically scheduled upon the occurrence or non-occurrence of drinking. Documentation of drinking in the natural environment is a difficult task since the alcoholic frequently consumes alcohol when he is alone. In lieu of direct observation, blood alcohol concentrations are an obvious means of objective assessment. Such data are most conveniently obtained via breath tests similar to the ones that law enforcement officers utilize to identify intoxicated motorists.The purpose of the present study was to investigate the influence of reinforcement contingencies on lowering blood alcohol concentrations obtained in an alcoholic's natural environment.     

The role of reference in children's acquisition of a miniature artificial language

Nursery school children were presented with a simple miniature artificial language in one of three conditions. In the first, the stimuli to which the words referred contained an inherent lawful relationship and the language syntax reflected this relationship. In the second, the stimuli contained an inherent lawful relationship but the language syntax did not reflect this relationship. In the third, no lawful relationship existed among the stimuli to which the words referred so the language syntax imposed an arbitrary relationship among stimuli. Subjects in the first group were able to produce more correct utterances than those in the other two groups when the stimuli to which the words referred were not present, suggesting that some form of semantic mediation mechanism was being used. Evidence from novel constructions indicates that for both groups using stimuli containing an inherent lawful relation there were interactions between semantic learning mechanisms and syntax learning mechanisms.     

Partial reinforcement effects and type of reward

In two experiments 68 rats were trained to bar press or run down a straight runway for food or for water under conditions of either continuous reinforcement or partial reinforcement. In both experiments, there was greater persistence of behavior which had been reinforced with food than with water. In Expt 2, the partial reinforcement extinction effect (PREE) was observed with food reward, but not with water.Within the context of the experimental procedures used, it can be concluded that the rat has mechanisms for developing persistence which are dependent on the specific motivational system involved. This conclusion is related to theories of partial reinforcement effects and to possible biological origins of the mechanisms.     

Semantic feature representations for normal and aphasic language

Aphasic and non-neurological patients grouped nouns on the basis of similarity of meaning. These word groupings served as input matrices for hierarchical clustering and multidimensional scaling analyses. The emergent structures suggest that, while the normal adult has a number of levels upon which to organize his lexicon, the adult aphasic's lexicon can be characterized as a set of partial entries that are tied to affective and situational data. The results also suggest that semantic feature representations derived from similarity-of-meaning judgments are of relevance in the study of factors which influence actual language performance.     

Moral reasoning development and graduate education

The Defining Issues Test (DIT) of moral reasoning development was administered to 20 advanced and 20 first-year graduate students, plus 40 college graduates matched to the graduate groups on sex, age, and verbal ability. A two-way ANOVA design was used to infer whether graduate education, selection, maturation, or a combination of these effects is (are) associated with group differences on the DIT. Results suggest that differences found between the graduate students and college graduates can be accounted for by a combination of maturational and selection effects, contrary to the hypothesized effects of formal education.     

Reaction time, intelligence, and attention

The roles of attention in reaction time and in the relationships among reaction time, intelligence, and achievement were analyzed. The subjects were 105 seventh-grade children. The results were generally consistent with most studies involving the Hick paradigm: both mean reaction time and the standard deviation of reaction time correlated with the intelligence and achievement measures used. Reaction time measures were correlated with attention and perceptual speed as well as with general intelligence, or g. Implications of these results for current theories linking reaction time and intelligence are discussed.     

Intratrial proactive interference in pigeon short-term memory: Manipulation of stimulus dimension and dimensional similarity

Proactive interference was studied using an intratrial preparation in two delayed matching-to-sample experiments employing pigeons. On interference trials, an interfering sample and a target sample were presented successively and were followed by a test consisting of a choice between two stimuli, one associated with each sample. Control trials were identical to interference trials except that the interfering sample was not presented. On both types of trials, choice of the comparison corresponding to the target sample was defined as correct. Colored fields and line orientations were employed as sample stimuli in Experiment 1, and samples of food and no food and of number of pecks were employed in Experiment 2. Interference was found to be equally robust regardless of whether the interfering and target samples were each selected from any of the four dimensions (color, line orientation, food/no food, or number of pecks). Amount of interference was found to be independent of whether the interfering and target samples employed on a trial were selected from the same dimension or from different dimensions. Evidence was also obtained suggesting that line orientation comparison stimuli are more likely to elicit a response not based on memory than are color comparison stimuli.     

The infant's acquisition of knowledge of bimodally specified events

Four-month-old infants viewed, for a duration of several minutes, two objects that bounced in synchrony with two percussion sounds. This synchrony was the only information tying each sound to its respective object. During the viewing the infants learned about the relationships between sound and object. Learning was revealed in two ways. In a search test, infants looked for an object when its sound was played. In a transfer test, infants' declining interest in a sound presented alone generalized to the visible object that the sound specified. Studies that reversed the spatial locations of the objects revealed that sound-object learning, rather than place or response learning, guided infants' perceptual exploration.