Unit 3 Biological Bases of Behavior

Studying the Brain, and Older Brain Structures Module 11 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. Studying the Brain, and Older Brain Structures 11-3 Describe the limbic system’s structures and functions.

How do scientists study the brain? lesion stimulation brain tissue is destroyed and researchers study the impact on functioning 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? 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? 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. These indicate brain functioning. CT (CAT), MRI, and fMRI 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? CT B. MRI C. fMRI D. PET EEG

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? amygdala B. thalamus C. medulla D. hippocampus hypothalamus

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? cerebral cortex B. medulla C. corpus callosum D. hippocampus hypothalamus

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: CT scan MRI fMRI

Learning Target 11-1 Review Describe several techniques for studying the brain’s connections to behavior and mind. Case studies and lesioning first revealed the general effects of brain damage. CT and MRI scans show anatomy. EEG, MEG, PET, and fMRI (functional MRI) recordings reveal brain function.

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.