Question

Question

Background

All models of memory suggest the existence of short-term memory (STM) function with two major features: 1) the quantity of information that can be held in STM is limited, and 2) information stays in STM for only a short period of time if something isn’t done to keep it there. One of the processes people use to keep information in STM is maintenance rehearsal, i.e., mentally repeating the information over and over again. 1 For many years, cognitive psychologists have studied the exact nature of these two specific characteristics of the STM system. In particular, the work 2 psychologists Lloyd and Margaret Peterson served as a starting point for research focused on how STM works. One major focus of STM research has been on the second notion mentioned above – that information resides in STM for only a short period of time. If that is the case, exactly how is information “lost” from STM? Does it simply decay over time like a wisp of smoke? Or, given its limited capacity, does the conscious stream of new information that enters STM just interfere with and “push out” the older information?

This assignment is an experiment based on the research technique used by the Petersons to explore the idea of “trace decay” in STM

3. It asks the question: “If the information in STM is prevented from being maintained, does it simply decay – and, if

so, what are the characteristics of this decay process?”

Explanation of the Assessment

There were nine trials in the experiment. (The initial practice trial is discarded.) Each trial started by presenting you with three words (called a word triad) for three seconds. After the three seconds, you engaged in a distractor task (counting backward by threes) before being asked to recall the words in the triad. The distractor task varied in length –either six, 12 or 18 seconds. There were three trials for each length of the distractor task 4 (randomly determined), making up the nine total trials. The recall period was 15 seconds in length. There was a five-second “rest period” between each trial.

Data Analysis

You need to convert the data to a mean percent correct recall for each length of distractor task before you begin

your analysis. See the instructions in the following spreadsheet:

Delay (Secs).                                             # Correct

6                                                       699

12                                                     461

18                                                     386

There has been a total of 95 participants in the experiment. This includes data from your class as well as data from other classes where I conducted the same experiment. The data listed are the total number of correct responses at each delay (distractor duration) for all 95 participants.

For example, for the 6-second delay, there were at 699 words correctly identified by all 95 participants across all three 6-second delay trials. Note that, for 95 participants, the highest possible score for each delay is 855 (i.e., 3x3x95). You can compute the mean percent recall for each delay by dividing the # correct for each delay by 855 and then if desired, multiplying by 100 to convert it to a whole number percent.

Questions/Tasks

5. The hypothesis is that recall performance of the word triads will worsen with

longer lengths of the distractor task? Is that hypothesis supported by the data?

6. Peterson and Peterson used the results of this experiment to support the

existence of a short-term memory function in which information fades away

without an active effort to maintain it. Explain how the results of this experiment

support that notion.

7. Many researchers have put forth the concept of proactive interference as an

alternative explanation for the results observed in the Peterson and Peterson

procedure. Explain proactive interference and how it could

be used to explain the results.

8. What does the Peterson and Peterson result say about the type of

environment that would be most helpful if you were in a situation where you

were trying to learn new material?

Answer 1

5.yes the hypothesis is that recall performance of the word traidnwill worsen with longer longer length ofdistractor task.

6.peterson is used the results of this experiment of support

7.manybreaseacrchesrs have put forth the concept of pro active interference as an alternative explanation for the results