Human Reflexes and Response Times

Human Reflexes and Response Times Auditory and Visual Cues

Reflex • Any response that occurs automatically without conscious

effort. • Two Types: – Simple or basic: built –in, unlearned responses. – Acquired or conditioned: result of practice and learning.

Reflex Arc: Afferent pathway

Stimulus

CNS

Integration Center

Receptor Sensory neurons

Response

Effectors Muscle or gland

Reflex is predictable because the pathway between the receptor and effector is always the same.

Efferent pathway Motor neurons

Receptor

Afferent pathway

Reaction Times • College age men: – 190 ms auditory – 160 ms visual

• Why ? – Auditory stimulus takes 8-10 ms to reach brain. Visual takes 20-40 msec.

Factors Influencing Reaction Time • Stimulus Strength

• Fatigue

• Arousal

• Alcohol

• Age

• Distractions

• Gender

• Breathing Cycle

• Direct vs. Peripheral

• Intelligence

Vision

Today’s lab • Lab should be done by EACH member of the group as a subject. • We will not compare class values, so ignore that part in labscribe questions. • Just compare within your own group.

Homework • Answer ALL questions from labscribe assignment.

• Write a methods section for a scientific paper. Do

NOT copy word for word from labscribe. Write them

in your own words.

Methods • Should describe what was done so that someone who is not in this class could repeat the experiment. • Do not give grave detail regarding the operation of labscribe. • Include information regarding the way data were collected and what analyses of those data you did (mean, standard error of the mean, comparisons).