The Brain and the Senses

birthdaytestAI and Robotics

Nov 17, 2013 (3 years and 8 months ago)



The Power of the Brain

Human brain has 10 billion neurons (30,000 can fit in
the head of a pin)

Each neuron has 1000
10,000 connections with other
neurons; up to 10 trillion possible

Messages between them travel in one thousandth of a

Average brain weighs 3
4 lbs. and consumes 20% of the
body’s oxygen supply and 20% of the blood flow

Almost fully developed by age 11, except for the frontal
lobe which develops through your early 20’s

Brain Facts

Brain produces 25 watts of power while you’re awake;
enough to illuminate a light bulb

At age 35, humans start losing 7000 brain cells a day

Alcohol and drugs also kill brain cells and weakens
connections between neurons

Stress over long periods will weaken the brain’s ability
to learn and remember

Same part of the brain interprets physical and
emotional pain

Your brain is more active at night than during the day

Brain Facts

People who ride on roller coasters have a higher chance
of having a blood clot in the brain.

An adult bottle
nosed dolphin’s brain is about the size
of a human adult’s brain.

A living brain is so soft you could cut it with a butter

There is no sense of pain within the brain itself. This
allows neurosurgeons to probe areas of the brain while
the patient is awake.

How do your senses effect your

What do you do when you smell something bad?

When you taste something good?

When you touch something hot?

When you see something beautiful? Something scary?

Have you ever listened to something that gave you
chills or brought you to tears?

Our senses are the way we
perceive the world

What we perceive depends on the relay of information
between the major sensory systems and the central
nervous system (CNS)

Information is processed, interpreted, and acted upon

Senses should work together in an integrated and
coordinated way = sensory integration

Allows for smooth development of complex motor
skills, learning and proper behavior

The Seven Senses

Five main senses: sight, taste, touch, hearing, smell


Less detectable:

Vestibular system: Related to sense of balance, spatial
orientation and movement

Proprioception: Sense of orientation of limbs and effort
necessary for motion

Interoception: Detection of pain, hunger, heat, time,
bladder, etc.

Senses developed in utero (vestibular first)

Vulnerable and subject to damage through stress or
illness during pregnancy or infancy

Issues associated with learning disabilities,
coordination problems, and behavioral/emotional

Sensory Integration Disorder: causes depression,
social anxiety, etc.

Visual Perception

Lens focuses on an image, transmits to light
membrane at the back called retina

Retina: part of the brain that translates patterns of
light into neuronal signals, causes neural impulses


The McGurk Effect

Auditory Perception

Vibrations detected by ear drum; simplifies air
pressure waves into a single of amplitude

Inner ear detects distribution of vibrations with hair
cells in basilar membrane

Converts vibrations into pattern of nerve
firings on the
auditory nerve which transmits sounds to brainstem


Music has strong effects on emotion and is associated
with memories

Voice recognition begins in the womb

Olfaction: Sense of Smell

Humans can distinguish over 10,000 different odor

When you inhale, the air hits millions of cilia (little
hairs) containing olfactory receptor neurons

The shape of the inhaled molecules is identified and
turned into electrical signals sent to the brain

The Power of Smells

Can effects purchasing decisions, perception of a
person or place, your generosity, and political leanings

Example: Clean smells tend to make people more honest
and fair in their interactions as well as generous

Properly themed smells for a product or place create a
positive image and memory

Animals use pheromones to select mates

Gustation: Taste

Substance reacts chemically with receptors in the
10,000 taste buds on the human tongue, cheeks, and

Taste works together with senses of smell,
temperature, texture and pain to determine flavors

Sweet, sour, bitter, salty and savory determined by
interactions with molecules and ions

Taste senses what is harmful and beneficial (aversive
or appetitive)


Three categories of tasters: supertasters (25%),
medium tasters(50%), and non
tasters (25%),
depending on density of taste buds

Supertasters are drawn to salt and sensitive to bitterness

Very picky eaters are often supertasters while very non
picky eaters might be non

Tactition: Touch

Somatosensory system reacts to stimuli using different
receptors on the skin, bones, organs, muscles, joints
and cardiovascular system

Integration of senses/receptors including those for
pain, temperature, bodily orientation, etc.

Information passes via sensory nerves through the
spinal cord to the parietal lobe and cerebral cortex

Touch and Behavior

Feeling “warmth” in the sense of closeness is closely
tied to actual heat: talking with someone over a warm
cup of coffee increases sense of closeness and caring

Sitting in a soft chair makes you more relaxed and
“soft” in negotiations, like at a car dealership

Holding a wooden block vs. a soft blanket effects your
perception of a social interaction

Physical sensory comfort level effects mood, emotions
and behavior


Disorder where one sensory input is involuntarily
linked to another: hear colors, see sounds as shapes,

The artist Kandinsky: painting symphonies