A Well Designed Investigation Catch It!

Engage in Reaction Time The soccer goalie on the cover page sees the ball coming and has to move quickly to reach and catch the ball. In less than a second, he must see where the ball is traveling and know where to move his arms, legs, and hands so he can catch the ball before it goes into the goal. How can the goalie make all these decisions so fast? (student responses)

Explore Reaction Time Today you will explore how quickly people react to catch a falling ruler. Then, you and your partners will compare the reaction times of different people.

Teacher Model (Procedures) The teacher (starter) holds the ruler vertically (straight up and down). The student opens the fingers of the catching hand and holds them near the bottom of the ruler, right next to the “O” cm line (without actually touching it) Without warning, the starter lets go of the ruler and the student (catcher) catches it by quickly pinching the fingers around the falling ruler. The teacher reads the measurement on the ruler at the point where the fingers are holding it. All members record the distance the ruler dropped in a data table. Repeat several times.

Record Your Data Use the following data table to record your reaction time for each trial (3 trials). Record your average reaction time for 3 trials. Students should work in pairs (one person is the starter, and the other is the catcher) Students should collect all the data from each member of their team (see data table on next slide)

Distance Ruler Dropped/Reaction Time Distance Ruler Fell (cm) Reaction Time (sec.) 1 .05 2 .07 3 .08 4 .09 5 0.10 10 0.14 15 0.18 20 0.20 25 0.23 30 0.25

Data Collection Table See Data Table 2016

Class Data Table (see word document)

Analyze the Data Compare the class data Which of your subjects had the fastest reaction time? What factors contributed to the different reaction times? Were there any similarities among the people with the fastest reaction times? List observations and questions for research.

Data Observations Fast Reaction Time Traits Slow Reaction Time Traits

Questions For Further Research? What factors influence human reaction time? How do your senses get information to the brain and how does your brain respond? (list student questions)

Reaction Reflection Reaction Time Definition: The interval of time between application of a stimulus and detection of a response. Reaction time (RT) is the elapsed time between the presentation of a sensory stimulus and the subsequent behavioral response

Types of Reaction Time Simple reaction time is usually defined as the time required for an observer to detect the presence of a stimulus. For example, an observer might be asked to press a button as soon as a light appears. Simple RT to detect the onset of a light flash is approximately 150 to 300 milliseconds[3].

Reaction Time in Your Body Stimulus 􀃆(Drop Ruler) Sensory Neuron 􀃆(Sends message to spinal chord) Spinal Cord or Brain 􀃆(Brain receives message) Motor Neuron 􀃆sends message back to response area Response (the action that responds to the stimulus)

Sensory neurons convert a stimulus into an electro-chemical signal, which flows the length of the sensory neuron(s), then through a neuron or neurons of the central nervous system, and then through the length of the motor neuron(s). Generally, motor neurons will cause a muscle to contract or a gland to secrete a substance. Reactions that involve only the receptor, the spinal cord, and the effector, are faster than those which involve processing in the brain. Reactions which only travel to, through, and from the spinal cord are often called spinal reflexes or cordmediated reflexes; withdrawing one’s hand from a hot stove is an example of such a reflex.

Types of Reaction Time In ‘simple reaction time’ experiments, there is only one stimulus and one response. Catching a dropped stick, or hitting a button when a light changes are examples. In ‘recognition reaction time’ experiments, there are symbols to respond to and symbols to be ignored. In ‘choice reaction time’ experiments, there are multiple stimuli and multiple responses. The reaction must correspond to the correct stimulus. Typing a letter which matches a printed letter prompt is an example of this type of experiment

What Affects Reaction Time? (list factors)-see next few slides for some help!

Factors Effecting Reaction Time

Setting Up “A Well Designed Investigation” DECIDE: Introduce an independent variable (what you are changing) and form a testable question and a hypothesis based upon the control set up (ruler drop time experiment) DESIGN: Form a set of procedures for the experiment CREATE: Create a data table to organize the collection of your dependent variables (what you are measuring or recording) CONDUCT: Perform the experiment and collect the data (put all data on data table) CALCULATE: The average time it took each student in your group to catch the ruler GRAPH: Create a bar graph that compares the average reaction times of the students for the factor you tested INTERPRET THE DATA: Forma conclusion discussing how the independent variable affected the reaction time of each person.

Present Your Findings: Poster Rubric The testable question your group was investigating is clearly visible A brief description of how your group did your experiment A bar graph demonstrates your findings A conclusion is included that includes data support