Complete the following lab activity:

Lab 10a: Working Memory: Remembering Limb Movements

Introduction

Purpose: To demonstrate the characteristics of working memory for remembering limb movements. Different retention interval conditions are compared to determine how each condition influences retention test performance. Forgetting is inferred from the amount of error occurring during the retention test, which means that a higher amount of error indicates that more has been forgotten than a lower amount.

Textbook Reading

Chapter 10

Task and Equipment Needed

The task is a line-drawing task. The blindfolded participant draws a line of a self-selected length along a ruler or straight-edge. This drawing activity is followed by a retention interval of a specified length which may include an activity. At the end of the retention interval the blindfolded participant attempts to draw a line that is the same length as the previously drawn line.

Equipment

Pencil (Note: If available, two different colored pencils would be preferred, one for the initial line and the other for the reproduced line).

Blank paper

Ruler or straight-edge

Procedures

You will need another person to do this experiment. One should be designated the participant and one the experimenter. Both should be seated so that they face each other. The participant experiences three trials in each of three different retention interval conditions: (1) Immediate recall; (2) 20-sec. unfilled retention interval; and (3) 20-sec. filled retention interval. Each trial involves the following protocol: (1) Goal movement - The participant draws a line of a desired length along the ruler or straight-edge. (2) Retention interval - The participant engages in the requirements of the retention interval. (3) Movement recall - The participant draws a line along the ruler or straight-edge that reproduces the line drawn in (1).

Retention interval conditions

Immediate recall - The participant begins movement recall as soon as possible after completing the goal movement.

20-sec. unfilled retention interval - The participant sits quietly for 20 seconds.

20-sec. filled retention interval - The participant counts backwards from a 3-digit number, which is given by the experimenter, for 20 seconds.

Procedures for each trial within each retention interval condition

Each participant will perform three trials in each retention interval condition, which should be experienced in the same order as described above.

Before beginning trial one of the Immediate Recall condition, the experimenter blindfolds the participant; puts a pencil in the participant's hand, and positions the participant's hand and pencil at the beginning of the ruler or straight-edge. The experimenter guides that participant's hand and pencil along the ruler or straight-edge to familiarize the participant with the type of movement that will be required. The experimenter should allow the participant to move to the farthest point possible for the line drawing task.

The experimenter places the participant's hand and pencil at the beginning of the ruler or straight-edge, and issues the verbal instruction "Draw a line of any length."

The participant returns his or her hand and pencil to the starting point and engages in the appropriate retention interval condition. If the condition is the 20-sec. filled retention interval, the experimenter should immediately say a 3-digit number from which the participant should count backwards by 3's for 20 seconds. A different 3-digit number should be used for each trial.

To begin the movement recall, the experimenter should move the participant's hand to a different start location than he or she used for the goal movement. The experimenter should then issues the verbal instruction "Draw a line that is the same length as the one you just drew."

Repeat numbers 3, 4, and 5 for two more trials in the retention interval condition. At the end of the three trials, begin the three trials for the following retention interval condition.

Recording the line drawings and measurement procedures

Use three blank sheets of unlined paper for the line drawings. On the top of the long side of each sheet write the name of each retention interval condition and the participant's name. Along the left side of the sheet, write the numbers 1, 2, and 3 so that they are spaced in such as way to allow two lines to be drawn by each number. These numbers indicate the trial numbers for the retention interval condition.

If the participant uses the same pencil to draw the goal movement and recall movement, it is important to label each line for each trial.

After the participant completes the 9 trials, measure the length of each line (mm units are preferred) and record the length beside the line.

To determine the error for the recall line, subtract the length of the goal movement line from the recall movement line (i.e., error = recall movement - goal movement). Write this value (including the algebraic sign) on the right side of the sheet beside the recall movement line. Note that recall lines that are shorter than the goal lines are designated by a minus algebraic sign, and recall lines that are longer than the goal lines are designated by a plus algebraic sign.

Results

Individual Data Table

Name Section Date 

Questions

AE       

CE

VE