Humans perceptually extract quantity information from our environments, be it from simple stimuli in isolation, or from relational magnitudes formed by taking ratios of pairs of simple stimuli. Some have proposed that these two types of magnitude are processed by a common system, whereas others have proposed separate systems. To test these…

To determine whether the distraction effect associated with material rewards in discrimination learning can account for the superior performance of reward groups in probability learning, the performance of 144 school children (preschool, second, and fifth grades) on a two-choice successive discrimination task was compared under three reinforcement…

Results indicated the following: unitary stimuli were easier to encode; partitioned stimuli were easier to recode; recoding was much more difficult than encoding; extended training improved performance; second graders were slightly better at encoding and much better at recoding than were kindergarten children. (Author/DB)

Study supported in part by U.S. Office of Education Grant.

This study tested the prediction that a satiation effect would be observed only for noncontingent social stimuli, and not for groups presented with contingent stimuli. (Author/SB)

Coding and recoding of hypothesis information was studied with college students and third, fifth, and seventh graders. Deficiencies in young children's ability to code, but not recode, contributes to their less efficient performance on discrimination problems. (DP)

Two studies of 7-year-olds and college students tested the hypothesis of a developmental difference in the degree to which subjects' memory performance was controlled by categorical properties vs. specific instance properties of test items. (GO)

A four choice discrimination problem was used to examine imitative behavior in children matched in mental age but differing in chronological age. The finding that older children imitated less than younger children is discussed in terms of socialization. (DP)

This study tested Levine's hypothesis testing model of discrimination learning with a procedure for determining which hypothesis is sampled without introducing blank trials. (DP)

Liniar functions fitted to the proportion of optional reversal shifts as a function of log CA were used to assess the effect of stimulus and training variables on the development of reversal-shift. (ST)

Main effect of reinforcement for mean response latency indicated that subjects took longer to respond under disapproval than under approval or silence. (Authors)

Subjects were trained against their initial dimensional preference in a two-dimensional simultaneous discrimination learning task. (RH)