Reconstruction of arbitrary versus logical sequences by preschool children

The ability of preschool children to construct and reconstruct ordered sequences was examined in a series of four experiments. In Expt. 1, the task was to copy, with the model present or absent, the order of items pegged on a clothesline. In Expts. 2–4, the subjects were required to reconstruct ordered series of pictures from memory. In all experiments, the orders were either logical or arbitrary. Reconstruction of an arbitrary series of events is within the problem solving capacity of 4-yr-old children if (a) reconstruction takes place in the presence of the model or follows immediately upon the removal of the model and (b) the original sequence is presented simultaneously. If, however, the lag between viewing and reconstruction is increased and/or the original set is not viewed simultaneously, as a unit, performance declines. The provision of an inherent order to the items within a set, either by introducing a connective narrative, or a depicted logical sequence, is sufficient to maintain that order over time and to provide a unifying cohesion to the items when viewed successively.     

The effect of a teacher's presence on the classroom behavior of conduct-problem children

Six institutionalized conduct-problem children performed in a classroom under three reinforcement conditions: (1) noncontingent reinforcement: (2) reinforcement for being on task and (3) reinforcement for the accuracy and rate fo their academic behavior. Within each of these conditions, the teacher was either present throughout the class session or absent for a portion of the session. In the teacher's absence, on-task behavior was markedly reduced and disruption was markedly increased, regardless of the reinforcement condition in operation. In contrast, the teacher's absence had no effect on academic accuracy and had a major effect on academic rate only when reinforcement was delivered noncontingently. Furthermore, the extent to which the children became disruptive in the teacher's absence was reduced when reinforcement was contingent upon academic accuracy and rate, instead of being contingent upon being on task or delivered noncontingently. It is suggested that the reinforcement of academic behavior, rather than on-task behavior or classroom social behavior, not only will improve the latter behaviors as well, but possibly also make them less dependent upon the presence and continued surveillance of the teacher.     

The selective impairment of semantic memory

The selective impairment of semantic memory is described in three patients with diffuse cerebrallesions. These patients, selected on the basis of a failure to recognize or identify common objects (agnosia for objects), were investigated in detail. In particular, their perceptual, language and memory functions were assessed, and the limits and properties of their recognition difficulties explored.

It was found that knowledge of pictorial representations of objects, and of words, was impaired or impoverished, and in both instances knowledge of subordinate categories was more vulnerable than superordinate categories. Evidence is presented that this impairment of semantic memory cannot be accounted for by intellectual impairment, sensory or perceptual deficits, or expressive language disorder. The implications of damage to the semantic memory system for the operation of other cognitive systems, in particular short and long-term memory functions, are considered. Some tentative evidence for the structural basis for a hierarchically organized modality-specific semantic memory system is discussed.     

Effects of alcohol and marijuana on dynamic visual acuity: I. Threshold measurements

Alcohol and marijuana produce significant dose-related reductions in dynamic visual acuity. Ten subjects participated in a double-blind experiment involving three dose levels of each drug (including placebo). The reduction of DVA produced by alcohol (1.0 ml 95% ethanol/kg body weight) was greater than for marijuana (15 mg Δ-9-tetrahydrocannabinol), and we suggest that this difference was produced by differential oculomotor effects of the two drugs. We have speculated that reduction in DVA under alcohol may be a contributing factor in alcohol-related traffic accidents.     

The influence of texture on judgments of slant and relative distance in a picture with suggested depth

Six surfaces from natural environments with different visual textures were photographed at angles of 60, 65, and 70 deg from perpendicular. Measurements were taken of 24 Ss’ judgments of the inferred angles of slant and inferred midpoints of the six textured surfaces represented in the photographs which were viewed in the frontoparallel plane. Judgments of both slant and relative distance within the photographs were influenced by represented angle of slant and by variations in surface texture.     

A digital system for recording startle,responses in small animals

An easily constructed, isometric startle-recording system is described. The animal enclosure is attached to a plywood board-which, in ten, is mounted in a “springboard” arrangement. Movement is detected by a phonocartridge mounted beneath the chamber, and a digital record of this movement is obtained through the use of a voltage-to-frequency converter. A brief experiment in which the system was used to assess the rat’s reaction to electric footshock is also presented.     

Modification of deficits in reading for comprehension

Subjects were asked to read a passage orally and then to answer questions about the passage. When praise and pennies were given for correct answers, the percentage of correct answers increased in two sixth-grade subjects whose reading for comprehension was tested to be 2 yr below grade level. The behavior of these subjects was compared to that of two subjects whose reading for comprehension was tested to be on grade level. Although no evidence for changes in the accuracy of answering comprehension questions is found in the previous literature, the percentage of correct answers in the children with deficits increased to approximately the same level as the children tested to be on grade level.     

Productivity and uniqueness in continued word association as a function of subject creativity and stimulus properties

Ninety-six male and 44 female college students gave written continued associations for 2 minutes to each of 24 stimulus words and then completed the Remote Associates Test and the Revised Art Scale No significant relationship was found between the creativity measures for either sex Few relationships, differing for males and females, were found between the creativity measures and associative productivity or uniqueness Productivity and uniqueness were found to be substantially related, and common responses occurred earlier in time than unique responses The properties of the stimulus words (frequency, form class, and slope of associative hierarchy) had marked effects on response productivity and uniqueness The study confirms the strong impact of stimulus properties on associative productivity and demonstrates similar effects on uniqueness The creativity data, yielding weaker and less consistent relationships, are in keeping with a specificity theory but lend only limited support to Mednick's associative hypotheses.     

Interaction effects of social and tangible reinforcement

Interaction effects between tangible and social reinforcement with children were investigated by comparing bar press rates of three groups of kindergarten children under three different reinforcement conditions: tangible, social, and tangible alternated with social reinforcement. Following the reinforcement period bar press rates of the three groups were compared during a brief period of nonreinforcement. In addition, the effects of sex and density of reinforcement were investigated.     

Conditioned taste aversions: Two-stimulus tests are more sensitive than one-stimulus tests

Weanling and mature rats were presented with saccharin or saline solutions for 1 h on alternate days. Following exposure to saccharin, rats were injected with 0, 21, or 37 mg/kg of cyclophosphamide. Injections had no significant effect on saccharin preference in one-stimulus tests, but had a highly significant effect in two-stimulus tests.