Asymmetries in the acquisition of polar adjectives: Linguistic or conceptual?

This study was designed to determine whether the asymmetry in children's acquisition of polar adjective pairs is based on linguistic factors related to differences in adult usage and frequency or on an underlying conceptual difference. 24 children, aged 3;7–4;11, took part in a concept-learning task in which nonsense syllables replaced English words for the positive and negative ends of four dimensions: size, height, length, and thickness. The data indicate that the syllables for the negative end of each dimension have a longer learning period and a greater prelearning error rate. These results support the hypothesis that the asymmetry observed in the acquisition of polar adjectives is based on an underlying conceptual asymmetry.     

The development of conceptual and rote recall skills among school age children

One hundred eighty children from Grades K, 5, and 9 performed a recall task within one of four instructional conditions: serial recall; standard free recall; labeling free recall; labeling cued recall. The task required that Ss view and recall items from three successively presented sets of categorized pieture stimuli. Controls were imposed upon the associatice relatedness of items within sets so as to minimize the occurrence of associative responding during recall. The clustering data showed that kindergarten and fifth grade children are able to use conceptual skills to effectively mediate recall, but fail to effect these skills on a spontaneous basis in free recall. The results were discussed in line with the hypothesis that young children fail to engage in planful cognitive activity in recall tasks.     

Speech acquisition in a nonverbal isolate child

The present study attempted to evaluate experimentally the relationship between two response classes: cooperative play and speech. One child was observed in a preschool free-play setting. Base rates of speech and play with peers indicated that the child never spoke to or played with peers during free-play periods. Base rates of teacher attention were observed to fluctuate directly with the child's isolate play. When differential attention and extinction operations were presented, removed and presented again, the frequency of cooperative play with peers increased, decreased and increased accordingly. Moderate fluctuations in verbal behavior also correlated with the presence and absence of the differential attention and extinction operations, even though the operations were applied only to cooperative play. The results suggest that some nonverbal isolate children may begin producing speech when play behaviors with peers are reinforced by teachers.     

Developmental trends in children's component selection

A new method is introduced for assessing children's component selection—i.e., the disposition to attend to a single feature of multifaceted stimuli. Eight-year-old children were found to exercise component selection to a lesser degree than 4-year-olds; while children at both age levels attended primarily to one stimulus component (shape), the older children showed a moderate amount of attention to a secondary redundant feature (color) as well. However, a comparable age difference in attention deployment was not observed when a single stimulus dimension (shape) was “relevant” in two variant tasks. These results imply a developmentally increasing ability to distinguish between conditions in which attending to redundant stimulus information can and cannot be useful. That this ability undergoes little further development beyond age 8 was suggested in a second experiment with 8- and 12-year-olds in which the three tasks produced relatively similar developmental trends in performance.     

Between-chains and within-chain speed gradients as functions of length

Two experiments examined between-chains and within-chain speed gradients as functions of length. The first, involving straight runways, revealed hyperbolic gradients within chains for each of three lengths, .61, 1.22, and 2.44 m. Between-chains comparisons showed a goal gradient effect confined to the start box segment and a long-chain depression effect in the last two segments. The second experiment, involving discrete-trial fixed-ratio bar-pressing schedules of FR(1 + 4), FR(1 + 8), and FR(1 + 16), showed goal gradient effects for starting speeds and for speeds across the first segment beyond start. Also, confounding effects apparent in the runway, of acceleration, deceleration, and long-chain depression, were diminished or absent in the bar-pressing situation.     

Effects of prefeeding on performance with body weight held constant

Two experiments are reported in which rats received either no prefeeding, nutritive substance prefeeding, or nonnutritive substance prefeeding prior to running in a straight alley. The running-speed data supported body weight as an overall measure of hunger drive. Performance was a function of body weight but not stomach weight or associated stomach bulk.     

Interactive effects of deprivation in the albino rat

The interactive effects of feeding and drinking schedules were investigated in three experiments. Twenty-four hour water-deprived rats consumed their entire obligatory water intake prior to feeding, whereas 24-hr food-deprived rats consumed only small quantities of food prior to drinking. This drinking was apparently due to a shift of water stores rather than an actual negative water balance. Experiment 3 investigated the effects of 24, 48, or 72 hr of water, food, or total deprivation. Water-deprived rats did not adequately suppress food intake and became thirstier than totally deprived rats. The effects of total deprivation were essentially identical to those of food deprivation. These experiments indicate the degree to which deprivation schedules impose restrictions on the reinforcement parameters of behavioral experiments.     

A two-phase model account of aversive classical conditioning performance in humans and rabbits

A two-phase model was applied to classical conditioning performance in man and rabbits. During phase 1, response probability remained constant. During phase 2, response probability generally increased, although one operator was sufficient for a majority of Ss and two operators were required for a minority of Ss. The latter Ss exhibited increases in responding after a CR trial and decreases in responding after a non-CR trial. The pattern of parameters was similar for man and rabbits. In man, increases in UCS intensity resulted in a decrease in the duration of phase 1 and an increase in the limit of the operators for those Ss requiring more than a single operator to describe performance during phase 2. The value of employing a model to describe the data and understand the effects of independent variable manipulation was discussed.     

Structural ambiguity in serial pattern learning

Four experiments on serial anticipation learning of lights by college students show that (a) the operations of transposing and taking the mirror image are used, (b) temporal inversion is not used, (c) a sequence made of two contrasting halves may be as easy to learn as a sequence having a single homogeneous hierarchical structure. Data revealed intrasequence confusion errors made by importing an operation from one part of the sequence to another. In homogeneous sequences, subjects appear to lose track of where they are in a sequence, and therefore repeat an operation already performed. The evidence supports the idea of an hierarchical cognitive structure, but shows that learning is not a simple function of that structure. Errors and difficulties arise from structural ambiguities, substrings of events that can be reconciled with more than one possible cognitive structure.