# Psychophysics, Anthropometrics and Ergonomics

User Generated

PuneyvOrne917

Computer Science

## Description

Do the "Classic" visual/motor ruler reaction time measurement study, as follows:

1. Using a rule, hold it near the end (highest number) and let it hang down
2. Have a participant put their hand at the bottom of the ruler and have them ready to grab the ruler (they should not be touching the ruler)
3. Tell the participant that you will drop the ruler sometime within the next 5 seconds and they are to catch the ruler as fast as they can after it is dropped
4. Record the level (inches or centimeters) at which they catch the ruler

Repeat multiple times (we recommend 20 times) varying the time the ruler drop within the 5 second window.

Then repeat with a different participant.

Use either the formulas or chart (to right) to convert measures to response times:

d = ½ g t2 or

Where:

t = time (in seconds)

d = distance (in cm)

g = gravity of 980 cm/sec2 or 385.8 in/sec2

Write up your design, procedures, materials, findings and conclusions (use the scientific paper format - module 2G). Include the following:

• A simple block diagram model (no more than about 6 blocks) of the visual-motor processes involved, include both sensory and cognitive processing aspects
• Hypothesis and null hypothesis
• Independent, dependent and confounding variables
• Descriptive analysis: mean, median, mode, range and scatter plot
1. Which participant is fastest? Is the difference significant?
2. Is the data skewed? Explain this result.
3. Over time, does reaction time increase, decrease or stay the same? Explain this result.

User generated content is uploaded by users for the purposes of learning and should be used following Studypool's honor code & terms of service.

Hi that is the copy of the report please check at it to confirm whether it satisfies your expectations

TITLE: VISUAL / MOTOR RULER REACTION TIME MEASUREMENT STUDY

INTRODUCTION
This activity (ruler drop test) is about measuring the body’s response time and studying how
practicing affects the response time of the body to something that you see. This experiment tests
how fast a person’s brain can interpret visual information about an object falling into actions such
as catching the object. The shorter the time the brain takes to translate the information implies a
faster response time or reaction.
In this case the body’s response involves communication between the brain and parts of the body
such as the eyes and the body muscles via the nervous system. For this experiment, an observer is
required to grasp a dropping ruler once released by a colleague. It starts by the eye anticipating the
fall of the ruler. Once it is dropped, the eye sends a signal to the visual cortex, which in turn sends
a message the motor cortex. The motor cortex sends a message to the spinal cord, which then sends
a message to the muscle in the hand/fingers. The final process is the contraction of the muscles as
the hand grasps the ruler. All these processes involve individual neurons that transmit
electrochemical messages to other neurons. [1]
By repeating the dropping and grasping process, with time a participant’s response time reduces,
since practice makes perfect. Much of a person’s response time is the time takes by the nerve
signals and messages to travel from the brain to the spinal cord and the body muscles. [1]

MATERIALS
a)
b)
c)
d)

Metric ruler
Two participants
Table
Chair

PROCEDURE
1) Participant A should hold a ruler near its end and let it hang down
2) Let participant B sit on a chair, with good upright posture and place their forearm so that it
extends over the edge of the table, and at the bottom of the ruler ready to grab it (they
should not be touching it)
3) Participant A will drop the ruler sometime within the next 5 seconds and B is t...

### Review

Anonymous
Great study resource, helped me a lot.

Studypool
4.7
Indeed
4.5
Sitejabber
4.4