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).