Developmental differences in frequency judgments of words and pictures

Children in kindergarten, third, and fifth grades were presented a list of either pictures or words (with items presented for varying numbers of times on the study trial). In both picture and word conditions, half of the Ss estimated how many times each item had been presented (absolute judgments) and the other half judged which of two items had occurred more often on the study trial (relative judgments). The primary finding was that while frequency judgment performance improved with age for both pictures and words, there was relatively greater improvement for pictures (i.e., the picture-word difference increased with age). These results lend strong support to the frequency theory of discrimination learning and, in particular, may be useful in accounting for effects associated with age and with age by stimulus mode interactions.     

Selective attention and the processing of integral and nonintegral dimensions: A developmental study

In two experiments, first- and fourth-grade subjects (age 6 and 9 years) performed a speeded card-sorting task with either integral or nonintegral dimensions. The dimensions were so arranged that subjects sorted on three types of task: (1) single dimension, (2) correlated dimensions, and (3) orthogonal dimensions. Results of the first experiment indicate that both first- and fourth-grade subjects sorted integral dimensions in a manner not qualitatively different from that of the adult (Garner & Felfoldy, Cognitive Psychology, 1970, 1, 225–241). In comparison with single-dimension tasks, performance was facilitated on the correlated-dimensions tasks and interference was observed on the orthogonal-dimensions tasks. Performances with nonintegral dimensions revealed an age-related processing difference. Fourth graders sorted nonintegral dimensions like the adult; no differences in performance were observed between the tasks. In contrast, first-graders sorted nonintegral dimensions as if they were integral. Interference was consistently observed on orthogonal-dimensions tasks. On correlated-dimensions tasks, interference was observed on easy tasks and redundancy facilitated difficult tasks. In the second experiment, first graders showed consistent facilitation on the correlated-dimensions task; all other results were indentical to those of Experiment I. The results were interpreted as consistent with perceptual learning theory (Gibson, Principles of perceptual learning and development. New York: Appleton-Century-Crofts, 1969).     

Note on the invariance of response latency in shuttlebox avoidance learning

Rats trained to avoid shock by running in a shuttlebox showed an orderly increase over trials in the probability of avoidance but no corresponding change over trials in the latency of the avoidance response. Both responding in the presence of shock (escapes) and responding prior to shock onset (avoidances) appeared to be stationary in time. Latencies were found to vary with different experimental conditions but in every case to be invariant over trials.     

Punishment of observing by a stimulus associated with the lower of two reinforcement frequencies

Three pigeons were used to investigate the effects of a stimulus associated with the lower of two reinforcement frequencies on the response producing it. In a three-key chamber, pecking the center key produced grain on alternating variable-interval schedules with mean durations of 2 min or 30 sec. Initially, green illumination of the keys accompanied the more favorable (30-sec) schedule and red accompanied the less favorable (2-min) schedule. Then the keys remained yellow unless the bird pecked one of the side (observing) keys to produce the discriminative stimuli for a 30-sec period. Subsequently, when red was withheld as a possible consequence of pecking a particular side key, the rate on that key increased; when red was restored, the observing rate decreased. Thus the stimulus associated with less frequent reinforcement had a punishing effect on the behavior producing it. When green was withheld on one of the side keys and the other key produced both colors, observing behavior was not maintained on the red-only key, but was maintained on the key that produced both colors.     

The perception of dichotic chords by hemispherectomized subjects

Hemispherectomized subjects display a strong ear dominance in their perception of dichotically presented two-tone chords. The frequency of the tone presented to the ear contralateral to the remaining hemisphere dominated the pitch mixture of the chord. The described effect does not vary with the age at which the hemispherectomy was performed. These results are consistent with the hypothesis, developed to account for findings in normal subjects, that the pitch mixture of a dichotic chord is determined by a subcortical pitch processor. The effects observed in hemispherectomized subjects may result from an interruption of an efferent pathway from the cortex to the subcortical pitch processor or from an asymmetrical degeneration of the processor which may be located in the thalamus (medial geniculate).     

Metaphoric comprehension: Studies in reminding and resembling

The theoretical problems posed by metaphoric comprehension are discussed in the context of experiments on prompted recall. Listeners heard sentences of the form “Topic is (like) Vehicle.” In most cases, a statement of the implicit resemblance (the “ground”) was very effective in prompting recall of its related metaphor. This result could not be attributed to the activation, transfer, or additive combination of pre-existing properties of the topic and vehicle terms or to pre-existing associations between grounds and sentence terms. It is argued that the vehicle domain guides a novel schematization of the topic domain, that the perceived resemblance is a higher-order relation among entities (both explicit and implicit) in each domain, and that this abstract relation constitutes the “functional memory unit.” Prompted recall may begin with recognition of this previously experienced relation.     

Process assessment: An examination of reinforcer effectiveness and predictive validity

This research describes an assessment procedure based on measures of actual learning. First-grade children (N = 120) learned five sight vocabulary words under feedback only, and were then assigned to one of five conditions where they learned five additional words either under feedback, praise, candy, praise and candy, or reproof. In a sixth condition (reciprocal to the first treatment), students learned the first five works under praise and the second five under feedback only. Although results indicated no differences in learning rate under different reinforcement conditions, learning measures under feedback accounted for approximately 39% of the variance in achievement (r = .62), with combined reinforcement learning measures slightly improving prediction (r = .68). The order of treatments had no effect on learning rate. Implications for this process approach to assessment are discussed. Directions for future research are suggested.