UNIT 2: Biological Bases of Behavior
PART I: Biological Bases of Behavior
Learning Targets
11-1 Describe several techniques for studying the brain’s connections to behavior and mind.
11-2 Describe the components of the brainstem, and summarize the functions of the brainstem, thalamus, reticular formation, and cerebellum.
11-3 Describe the limbic system’s structures and functions.
How do scientists study the brain?
lesion
brain tissue is destroyed and researchers study the impact on functioning
stimulation
Brain regions are stimulated electrically, chemically, or magnetically and researchers study the impact on functioning
How do EEG, MEG and CT scans �image the brain?
EEG
A recording of the waves of electrical activity
across the brain’s surface measured by electrodes placed on the scalp.
MEG
A brain imaging technique that
measures magnetic fields from the
brain’s natural electrical activity.
CT
CAT
X-ray photographs taken from different angles and combined by computer to show
a slice of the brain’s structure; shows structural damage.
How do PET, MRI and fMRI scans �image the brain?
PET
A visual display of brain activity that detects where a radioactive glucose goes while the brain performs a given task. Shows activity.
MRI
A technique that uses magnetic fields and radio waves to produce computer-generated images of brain anatomy.
More detailed than CT scan.
fMRI
A measure of blood flow and brain activity by comparing successive MRI scans to show brain function or as well as structure.
Shows damage.
Which imaging techniques show structure and which indicate function?
These show the structures of the brain.
CT (CAT), MRI, and fMRI
These indicate brain functioning.
EEG, MEG, PET and fMRI
How do the various imaging �techniques compare?
AP® Exam Tip
Knowing which brain imaging technique would be used to show activity or structure is often tested on the AP® Exam.
Pay close attention to the chart on the previous slide and check your understanding of the various methods and results of brain imaging techniques.
1. What Would You Answer?
Which of the following scanning techniques measures glucose consumption as an indicator of brain activity?
B. MRI
C. fMRI
D. PET
Which structures make up �the brainstem?
What are the functions of the medulla?
at the base of the brainstem
controls heartbeat and breathing
What are the functions of the pons?
just above the medulla
controls sleep and helps coordinate movements
What are the functions of the reticular formation?
nerve network that travels through the brainstem into the thalamus
helps control arousal and filters incoming sensory stimuli
What are the functions of the thalamus?
at the top of the brainstem
relay station for incoming and outgoing sensory information (with the exception of smell)
2. What Would You Answer?
Damage to which of the following puts a person’s life in the most danger because it may cause breathing to stop?
B. thalamus
C. medulla
D. hippocampus
What are the functions of the cerebellum?
at the rear of the brainstem
processing sensory
input, coordinating movement
and balance, nonverbal learning and memory
Which structures make up �the limbic system?
What are the functions of the amygdala?
two
lima-bean-sized neural clusters
linked to
emotion, fear, and aggression
What does research suggest about the functions of the amygdala?
One study showed math anxiety is associated with hyperactivity in the right
amygdala (Young et al., 2012).
Another study linked criminal behavior with amygdala dysfunction
(Boccardi et al.,2011; Ermer et al., 2012).
Researchers found when people view angry and happy faces, only the angry ones increase activity in the amygdala.
(Mende-Siedlecki et al., 2013).
What are the functions of the hypothalamus?
below (hypo) the thalamus;
directs eating, drinking, body temperature
helps govern the
endocrine system via the pituitary gland, linked to emotion and reward
What does research suggest about the functions of the hypothalamus?
Stimulating the reward centers of the hypothalamus will motivate a rat to cross an electrified grid, receiving painful electric shocks, to reach a bar that will give additional stimulation.
What are the functions of the hippocampus?
Small structure with two “arms” that wrap around the thalamus
helps process for storage explicit (conscious) memories of facts and
events
What does research suggest about the functions of the hippocampus?
Humans who lose their hippocampus to surgery or injury also lose their ability to form new memories of facts and events (Clark & Maguire, 2016).
Those who survive a hippocampal brain tumor in childhood struggle to remember new information in adulthood. (Jayakar et al., 2015)
NFL players who experience one or more loss-of-consciousness concussions may later have a shrunken hippocampus and poor memory
(Strain et al., 2015).
3. What Would You Answer?
Damage to which of the following brain structures would affect the processing of new explicit memories?
B. medulla
C. corpus callosum
D. hippocampus
4. What Would You Answer?
Thomas fell and hit his head, so his parents brought him to the emergency room.
Explain how the following scans would give doctors different information about the type of injury Thomas may have:
Learning Target 11-1 Review
Describe several techniques for
studying the brain’s connections to
behavior and mind.
Learning Target 11-2 Review
Describe the components of the
brainstem, and summarize the functions of
the brainstem, thalamus, reticular formation, and cerebellum.
The brainstem: automatic survival functions
medulla: heartbeat and breathing
pons: coordinate movements
reticular formation: filters incoming stimuli; affects arousal
Thalamus: sensory control center
Cerebellum: coordination and balance; processes sensory information.
Learning Target 11-3 Review
Describe the limbic system’s
structures and functions.
The limbic system: emotions, memory, and drives
amygdala: aggression and fear
hypothalamus: maintenance functions, pleasurable rewards, control of the endocrine system
hippocampus: conscious memories
pituitary (the “master gland”) controls the hypothalamus by stimulating it to trigger the release of hormones.