Brain

Braintastic!

A Stiles Original Production

Brain Facts

• Male brains are slightly larger than female brains.

• Brain Tissue has no pain receptors.

• Adults can generate new brain cells and make new connections.

• Your brain uses about 20% of your body’s energy and makes up only 2% of your weight.

• The Cerebral Cortex has the surface area of a pillow case.

How much of our brain do we actually use?

• All of it!!

• Brain imaging techniques have debunked the alluring 10% Myth

Brain Imaging Techniques• PET Scan- reflects

blood flow and metabolic activity.

• MRI-shows brain structure (radio frequency)

• fMRI-combines strategies of PET and MRI

• CT Scan- x-ray• Angiography-dye,

shows blood vessels• EEG- measures brain

waves

Lobesand I don’t mean ear lobes

Frontal LobeThe frontal lobe can be kind of confusing because it has such a wide range of functions (motor movements to cognitive process)

Thinking, Reasoning, Decision Making, Personality, Planning, Judgment

• Would you like to meet Phineas Gage?

Phineas Gage’s Skull

The MOTOR CORTEX (Frontal Lobe)

The body’s parts (muscles) are individually controlled by the MOTOR CORTEX

Motor Homunculus

This bizarre drawing uses sizes of body parts to show the ability to perform complex movements. (The larger the space on the “MC” the body part occupies the more complex movement it will be able to make)

The right motor cortex controls muscles on the left side of the brain and vice versa.

Parietal Lobes

• Processes sensory info. (pressure, touch, pain)

• Receives sensory input for touch and body position.

• Processes information about size, shape, and texture.

Sensory CortexThis model shows what a man's body would look like if each part grew in proportion to the area of the cortex of the brain concerned with its sensory perception.

The sensory cortex is a narrow strip located on the front edge of the parietal lobe.

Body parts that occupy more space on the SC are more sensitive to external stimulation.

Sensory Homunculus

Touch, location of limbs, spatial coordination

Gate-Control Theory of PainGate open = Pain, Gate closed = No pain

• Experience of pain depends (in part) on whether the pain impulse gets past neurological “gate” in the spinal cord and thus reaches the brain.

• Different nociceptors detect hurtful temps, pressures, or chemicals. The spinal cord contains small nerve fibers

that conduct most pain signals, and larger fibers that conduct most other sensory signals.

Neuromatrix Theory of Pain• Theory that the

matrix of neurons in the brain is capable of generating pain (and other sensations) in the absence of signals from sensory nerves.

• Phantom Limb Pain clip.

DID YOU HEAR THAT?

Auditory Localization

• The brain calculates a sound’s location by using these differences.

– Timing (.000027sec. Diff)

– Sound travels @ 750 mph

• Sound Waves– Loudness (amplitude)

– Pitch (frequency)• Long waves; low frequency/low

pitch• Short waves; high frequency/high

pitch

Auditory Process: Perceiving Pitch

Place Theory: Links the pitch we hear with the place that is stimulated in the cochlea

Frequency Theory: Measures neural impulses travelling the auditory nerve.

Temporal Lobe: involved in hearing, speaking coherently, and understanding verbal and written material.

Primary auditory cortexAuditory Association Area

The Primary Auditory Cortex (top edge) receives electrical signals from receptors in the ears.

Auditory Association Area.

Further processing—makes sense out of sensations.

Wernicke’s Area (left temporal lobe) is necessary for speaking in coherent sentences and for understanding speech.

Damage to Wernicke’s area results in aphasia, which is a difficulty in understanding spoken or written words and a difficulty in putting words into

meaningful sentences.

Let’s Get Visual!

• Cones are clustered near the fovea.• Cones are used in daylight vision.• Cones produce high resolution vision, helps us see

detail and color.• Rods are denser in the peripheral of the retina. • Rod adaption process is much slower than that of

the cones. • They are responsible for our dark-adapted, or

scotopic, vision. • We have many more rods than cones.

What’s Happening?

• In the retina of your eyes, there are 3 types of color receptors (cones) that are most sensitive to either red, blue or green.

• When you stare at a particular color for too long, these receptors get "tired" or "fatigued."

• When you then look at the white background, the receptors that are tired do not work as well.

• Therefore, the information from all of the different color receptors is not in balance and you see the color "afterimages."

• You can see that you vision quickly returns to normal.

If you have ever been hit on the back if the head and saw “Stars”, you already know that vision is located in the OCCIPITAL LOBE.

Primary visual cortex

Visual Association Area

In visual agnosia, the individual fails to recognize some object, person, or color, yet has the ability to see and even describe pieces of parts of some visual stimulus

Neglect Syndrome

Group A

• You are going to look briefly at a picture and then answer some questions about it. The picture is a rough sketch of a poster promoting an upcoming event, a costume ball. Do not dwell on the picture. Look at it only long enough to “take it all in” once. After this, you will answer YES or NO to a series of questions.

Group B

• You are going to look briefly at a picture and then answer some questions about it. The picture is a rough sketch of a poster for

a trained seal act. Do not dwell on the picture. Look at it only long enough to “take it all in” once. After this, you will answer YES or NO to a series of questions.

Picture

In the picture was there . .

1. A car?2. A man?3. A woman?4. A child?5. An animal?6. A whip?7. A sword?8. A man’s hat?9. A ball?10. A fish?

• Top Down processing – you go beyond the sensory information to try to make meaning out of ambiguity in your world

• What you expect (your experiences and your perceptual set) drives this process

• Bottom Up processing- digesting raw sensory information to make sense of something.

Perceptual Ambiguity

• Your brain tries to make sense of what you are looking at based on the region you are focusing on.

Corpus Callosum

Connects hemispheres

limbic systemEmotional link*amygdala*hippocampus

ThalamusRelay sensoryinformation

HypothalamusControls bodyMetabolism Regulates DrivesMaintenance Duties

Pituitary Gland

Secretes hormones-growth

Connects the brainstem to the forebrain. The midbrain is responsible for controlling sensory processes.

The hindbrain functions collectively to co-ordinate motor activity, posture, equilibrium and sleep patterns and regulate unconscious but essential functions, such as breathing and blood circulation.

Survival Functions

Anencephaly: Born with little or no brain tissue. Always Fatal.

Joseph Loren, 1999

Survival is limited to days. The longest a baby has survived with anencephaly is 2 months.

One reason babies can survive for a short while with virtually no Forebrain is because they may have parts of their hindbrain. (Pons, Medulla) Medulla controls vital reflexes.

It is the functions of the forebrain that define us as human and distinguish us from other creatures.