Conditioned stimulus duration and delay of reward as variables in a lever pulling situation

Ninety kindergarten children served as Ss in a lever-pulling experiment. They were randomly assigned to five experimental groups. A group (LIMI) receiving immediate CS offset and immediate marble delivery did not differ significantly on a starting speed measure from a group (LI) receiving only immediate CS offset. In contrast, Group LIMI was significantly superior to Group LI on a movement speed measure. These results were interpreted as being consistent with the contention that starting speed differences mainly reflect the effect of “dompeting responses”, while movement speed differences principally reflect effects of motivational variables. In another phase of the experiment, a factorial design (which included Group LIMI but excluded Group LI) utilizing two values of delay of marble reward and two values of delay of CS (“Black Light”) offset yielded results which indicate that delay of marble delivery affected starting speeds and that delay of CS offset affected movement speeds. Other results obtained indicate that children's performance on the first trial block was influeneed by watching E perform the same task during an initial demonstration trial, that the trial block to trial block starting speed correlations were positive but smaller in magnitude than corresponding positive movement speed correlations, and that the correlation between starting and movement time for 5-year, 7-month-old children was positive.