Robert E. Morin

Recognition reaction time and size of the memory set: A developmental study*

Kindergarten, fourth-grade, and college Ss were tested on a recognition reaction-time task with memory sets of two, three, and four items. Though overall reaction time (RT) varied with age, the slopes of the functions relating RT to size of the memory set did not differ significantly as a function of age. Within the context of a theory of recognition memory developed by Sternberg (1966), the results suggest that young children scan memory for familiar pictures as quickly as do adults.

Age Related Changes in the Effectiveness of Name and Visual Codes in Recognition Memory.

Abstract In the first of three studies college, third grade, and kindergarten Ss were able to determine that two stimuli presented 700 msec apart were the same more quickly if they were visually identical than if they shared the same name. If 3000 msec elapsed between stimulus presentations third grade and college Ss responded at the same rate in making both types of matches, whereas kindergarten Ss appeared to continue to respond more quickly in making visual matches. Study II was an unsuccessful attempt to replicate the kindergarten finding. A warning signal, presented 500 msec prior to the second stimulus, reduced RTs at both interstimulus intervals, but no significant differences in making visual and name matches occurred. In Study III first-graders, responding either with or without a warning signal, were found to respond like the older Ss in Study I. The warning signal again reduced RT at both intervals. The results suggest that Ss across a wide age range are able to use the visual properties of a stimulus for only a very brief period as the basis for making matching judgments.

Random generation: Number of symbols to be randomized and time per response

Attempts to randomize digits are relatively less successful the greater the number of digits to be randomized and the faster the rate at which responses must be made. However, increases in the number of digits and/or response rate result in improvements in information generated per unit time.

Short-term recognition memory for spatially isolated items

With from three to six digits presented prior to a recognition probe, the only evidence for a von Restorff effect existed in faster reaction times to probes of the isolated stimulus with sets of size 6.

Are these two stimuli from the same set? Response times of children and adults with familiar and arbitrary sets ☆

Abstract When fourth-grade children and adults decide whether two stimuli are from the same or different sets, reaction time data suggest that the S s use an encoding strategy if the sets have familiar names and a search strategy if the sets are arbitrarily grouped elements. Kindergarten S s show some signs of encoding, but also exhibit behavior suggestive of deficiencies in mediation and rehearsal, and a dependence on visual cues.

Short-Term Memory in Children: Keeping Track of Variables with Few or Many States.

Abstract Does ability to remember the most recent state of a variable (e.g., that dog was the last animal seen) depend on whether the variable has few or many states? When adult S s are tested in a keeping-track task, the answer to the question is negative, consistent with expectations from Millers argument that the capacity of short-term memory (STM) is better described in terms of “chunks” than in terms of “bits” of information. The present study tested the hypothesis that number of states is an important variable determining the retention of young children. The prediction follows from a consideration of the role played by rehearsal in the STM of children and adults. The obtained data are consistent with the prediction and show that retention is dependent on number of states with 4-year-old children as S s.

Reduction of redundant stimulus information in short-term memory

Twenty-six Ss were tested on a recognition memory task in which stimulus material was presented repetitiously on some trials. The number of items and the number of repeated itmes presented for memory were varied. A typical linear function relating reaction time of the recognition response to number of items in memory was found for nonredundant information. Evidence for the reduction of redundant information was provided by the finding that reaction times were alike on trials in which the amount of information remained constant although the number of items increased.

Keeping track of several variables: Number of variables and stimulus recurrence distributions

It can be easier to keep track of the states of many variables than to keep track of the states of few. This finding is attributed to changes in stimulus recurrence distributions (and required recency discriminations) which accompany changes in the number of variables to be monitored.

Short term memory and reaction time: keeping track of several variables

Reaction time (RT) and response accuracy depend on the remoteness, in terms of time and number of intervening trials, of a previous response which serves as the stimulus for a present response.