Biology & Behavior:Ways to Study the Brain, Parts

of the Brain, Split Brains

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Section 4: Observing the Brain

• Learning Goals:– Students should be able to answer the following:

1. How do neuroscientists study the brain’s connections to behavior and the mind?

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How We Observe the Brain• Phrenology– Created by Franz

Gall (1796)– Bumps on head

determine personality

• Dramatic Brain Injury– Phineas Gage Case

Study (1848)

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How We Observe the Brain• Electroencephalogram (EEG) An amplified recording of the

electrical waves sweeping across the brain’s surface, measured by electrodes placed on the scalp.

• PET (positron emission tomography) Scan is a visual display of brain activity that detects a radioactive form of glucose while the brain performs a given task.

• MRI (magnetic resonance imaging) uses magnetic fields and radio waves to produce computer-generated images that distinguish among different types of brain tissue. Images show ventricular enlargement in a schizophrenic patient.

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How We Observe the Brain

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EEG

PET ScanMRI

f-MRI

Section 4: Observing the Brain

• Reflection of Learning Goals:– Students should be able to answer the following:

1. How do neuroscientists study the brain’s connections to behavior and the mind?

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Good Understanding

Little Understanding

Fair Understanding

Section 4: Test Your Knowledge (#1)

1. People, like Phineas Gage, who have experienced severe damage to the frontal lobe of the brain seldom regain their ability to:

A. Make and carry out plansB. Recognize visual patternsC. Process auditory informationD. Process olfactory informationE. Integrate their multiple personalities

2. An EEG records:F. Direct electrical stimulation of the brainG. The number of neurons in the brainH. Electrical impulses from the brainI. Chemical activity in specific areas of the brainJ. Stimulation of the frontal lobe

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Section 4: Test Your Knowledge (#2)

1. Identify this type of imaging and hypothesis what it is showing:

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Section 5A: Brain Structure & Functions

• Learning Goals:– Students should be able to answer the following:

1. What specific brain areas control certain functions?

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The Old Brain (Brainstem)• Medulla

– Heartbeat and Breathing

• Pons “bridge”– Coordinates Movement and Sleep

• Reticular Formation– Net of Nerves Inside the Brainstem– Controls Arousal & Alertness– Example: When you name is called

• Locus Coeruleus– Center of Reticular Formation– Alertness and Panic

• Thalamus– Signal Switchboard– Relays information to your pleasure areas– Relays senses (not smell) information to cortex areas

• Ex: Information from eyes to visual cortex

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The Cerebellum “little brain”

• MAIN FUNCTION:– Coordinates balance &

movement • (ex. Walking, playing guitar hero)

• OTHER FUNCTIONS:– Judges time– Stores muscle memory– Discriminates sounds

and texture

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The Limbic System (Emotional)

• Amygdala– Aggression and Fear

• Hypothalamus– Hunger, Thirst, Sex, & Body Temp.– reward center & dopamine pathways

• Hippocampus–Memory

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The Cerebral Cortex• Frontal Lobes

– Thoughts & Decision Making– Contains Motor Cortex– Contains Prefrontal Cortex

• In charge of logic, step-by-step decision making, morals, and emotional control

• Parietal Lobes– Sensation/Touch– Contains Sensory Cortex

• Occipital Lobes– Vision Processing– Contains Visual Cortex

• Temporal Lobes– Hearing & Memory– Contains auditory cortex

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Section 5A: Brain Structure & Functions

• Reflection of Learning Goals:– Students should be able to answer the following:

1. What specific brain areas control certain functions?

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Good Understanding

Little Understanding

Fair Understanding

Section 5B: Brain Structure & Functions

• Learning Goals:– Students should be able to answer the following:

1. What specific brain areas control certain functions?

2. To what extent can a damaged brain reorganize itself?

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The Cerebral Cortex

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The Cerebral Cortex

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Association Areas

Association areas deal with high level thinking such as directions and location

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Language & The Brain• Aphasia is an impairment

of a language area in the brain, usually caused by left hemisphere damage.

• Broca’s area helps us use muscle movements for speaking and pronunciation (Aphasia here is indicated by speaking slowly with missing words)

• Wernicke’s area interrupts understanding of words. (aphasia of this area is indicated by garbled sentences or use of words that don’t make sense) 19

Example Aphasia: What do you do with a cigarette?Broca Aphasia: Uh…(long pause)…cigarette…uh…smoke it.Wernicke Aphasia: This is a segment of pegment, soap a cigarette.

Brain Plasticity

• The ability for the brain to modify itself after damage

• Amputation leads to phantom sensations

• People can generate new brain cells (Neurogenesis)

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Section 5B: Brain Structure & Functions

• Reflection of Learning Goals:– Students should be able to answer the following:

1. What specific brain areas control certain functions?2. To what extent can a damaged brain reorganize itself?

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Good Understanding

Little Understanding

Fair Understanding

Section 5: Test Your Knowledge1. Homework: Study parts of the

brain!!!

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Section 6: Split-Brain & Consciousness

• Learning Goals:– Students should be able to answer the following:

1. What do split brain reveal about the functions of our two brain hemispheres?

2. What is the “dual processing” being revealed by today’s cognitive neuroscience?

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The Two Hemispheres

Our brain is divided into two hemispheres.

The left hemisphere processes reading, writing, speaking, mathematics, and comprehension skills. In the 1960s, it was termed as the dominant brain.

• Right Brain– Creativity– Facial Expressions

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Which face is happier?

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The Two Hemispheres

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No Such Thing as Left-Brain or Right-Brain Dominance. You are NOT primarily left or right brained!

Split Brain Experiment (Sperry & Gazzagnia)

• With the corpus callosum severed, objects (apple) presented in the right visual field can be named. Objects (pencil) in the left visual field cannot. We cut the corpus callosum for seizures.

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Split Brain Experiment (Sperry)

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Split Brain Experiment (Sperry)Try drawing one shape with your left hand and one

with your right hand, simultaneously.

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Dual Processing: Who is really in control?

• Consciousness takes place in two forms:–High Road: Conscious ideas that we

think about and readily recall– Low Road: Unconscious feelings, ides

and experiences that influence our behavior and thought.

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About 1/3 of a second before you think of raising your hand, your brain has already started to process the movement

Section 6: Split-Brain & Consciousness

• Reflection of Learning Goals:– Students should be able to answer the following:

1. What do split brain reveal about the functions of our two brain hemispheres?

2. What is the “dual processing” being revealed by today’s cognitive neuroscience?

Mr. Burnes 31

Good Understanding

Little Understanding

Fair Understanding

Section 6: Test Your Knowledge 1. In people whose corpus callosums’

have not been severed, verbal stimuli are identified more quickly and more accurately:

A. When sent to the right hemisphere firstB. When sent to the left hemisphere firstC. When presented to the left visual field.D. When presented auditorally, rather than

visually.

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