2.4-2.9 How Do the Parts of Your Brain Function?

2.4 Our Understanding of How the Brain Works Has Improved Over Time

  • The central nervous system (CNS) includes the brain and the spinal cord. Together, these structures make possible the complex processing that humans can do.

  • Studies of patients with brain injuries showed that specific brain regions are specialized to process certain types of information (localization of function).

  • Modern methods let us study the brain in action:

    • EEG measures the brain's electrical activity.

    • Functional Magnetic Resonance Imaging (fMRI) maps brain activity during a mental task based indirectly on blood flow to different brain areas.

    • Transcranial Magnetic Stimulation (TMS) disrupts brain activity in a specific brain region, letting researchers explore the brain processes involved in particular mental activity and behaviors.

  • Connections to foundational principles:

    • Localization of function explains how specific regions contribute to particular cognitive and motor processes.

    • Imaging and stimulation techniques provide causal and correlational evidence about brain–behavior relationships.

  • Practical and ethical implications:

    • Noninvasive methods (EEG, fMRI, TMS) enable safer study of brain function, but must be used with informed consent and consideration of participant well-being.

  • Real-world relevance:

    • Understanding brain function supports education, rehabilitation after injury, and treatment of neurological conditions.

2.5 The Hindbrain and Midbrain House Basic Programs for Your Survival

  • The spinal cord carries sensory signals from the body to the brain and motor signals from the brain to the body.

  • The spinal cord is also responsible for basic reflexes.

  • The hindbrain is located at the top of the spinal cord and includes three main structures:

    • Medulla: regulates basic survival functions (e.g., respiration and heart rate).

    • Pons: regulates sleep and arousal and coordinates body movements.

    • Cerebellum: essential for movement, coordination, and balance.

  • The midbrain is located in the middle of the brain above the pons and includes the substantia nigra, which is responsible for initiating voluntary movements.

  • Significance:

    • These regions provide foundational, automatic control essential for life and daily function.

  • Connections to broader principles:

    • Basic autonomic and motor control systems interface with higher cortical areas to shape behavior and responsiveness to the environment.

2.6 Forebrain Subcortical Structures Control Your Motivations and Emotions

  • Beneath the cerebral cortex of the forebrain are four subcortical forebrain structures that are part of the limbic system:

    • (1) Thalamus

    • (2) Hypothalamus

    • (3) Hippocampus

    • (4) Amygdala

  • Together, these structures (forming part of the limbic system) support multiple functions:

    • (1) Thalamus: processes most sensory input.

    • (2) Hypothalamus: regulates the basic functions of the body and controls motivated behaviors.

    • (3) Hippocampus: forms memories.

    • (4) Amygdala: helps navigate environments and modulates memory processing during emotional arousal, contributing to emotional responses.

  • Additional notes:

    • These structures interact with cortical areas to influence learning, memory, motivation, and emotional regulation.

  • Significance:

    • The limbic system links physiological states with cognitive and emotional processes, shaping behavior in context (e.g., hunger, fear, reward).

2.7 The Cerebral Cortex of the Forebrain Processes Your Complex Mental Activity

  • The wrinkled cerebral cortex processes the most complex information in the brain.

  • The two halves of the brain—the left and right hemispheres—are connected by the corpus callosum, which lets information flow between the sides of the brain.

  • The cerebral cortex has four structural areas: (1) occipital lobes, (2) parietal lobes, (3) temporal lobes, and (4) frontal lobes.

  • Across the four lobes there are 6 regions that are specialized for processing certain information.

  • Relationship to broader principles:

    • Cortical specialization supports diverse cognitive functions (vision, touch, language, planning).

    • Hemispheric integration enables complex, coordinated behavior.

2.8 The Hemispheres Work Together With Some Specialization

  • Split-brain studies provide important insights into hemispheric specialization:

    • In split-brain patients, the hemispheres are separated, so information cannot be transferred from one hemisphere to the other.

    • The left hemisphere is primarily responsible for logical thought and language.

    • The right hemisphere is primarily responsible for spatial relationships and abstract thinking.

  • Practical takeaway:

    • For most people, the hemispheres work together in producing thought and behavior; people are not simply "left-brain" or "right-brain" dominant.

  • Real-world relevance:

    • Understanding hemispheric specialization informs approaches to education, rehabilitation, and interpreting neuropsychological assessments.

2.9 Using Psychology in Your Life: How Can You Succeed If You Have a Learning Disability?

  • A learning disability is a neurological disorder that affects the brain's ability to receive, process, store, or respond to information. Examples include ADHD and dyslexia.

  • If you have or suspect you might have a learning disability, contact a staff member of your campus office for disability support services or student affairs.

  • Educational implications:

    • Schools must provide equal opportunity to the benefits of education for people with learning disabilities by making accommodations in course presentation, assignments, and tests.

  • Ethical and practical considerations:

    • Importance of early identification, appropriate supports, and reducing stigma and barriers to learning.

  • Real-world relevance:

    • Supports enable students to demonstrate abilities and achieve academic and career goals.

Key Terms

  • Medulla: Regulates basic survival functions (e.g., respiration and heart rate).

  • Pons: Regulates sleep and arousal and coordinates body movements.

  • Cerebellum: Essential for movement, coordination, and balance.

  • Thalamus: Processes most sensory input.

  • Hypothalamus: Regulates the basic functions of the body and controls motivated behaviors.

  • Hippocampus: Forms memories.

  • Amygdala: Helps navigate environments and modulates memory processing during emotional arousal, contributing to emotional responses.

  • Occipital lobes: One of the four structural areas of the cerebral cortex, specialized for processing certain information (vision).

  • Parietal lobes: One of the four structural areas of the cerebral cortex, specialized for processing certain information (touch).

  • Temporal lobes: One of the four structural areas of the cerebral cortex, specialized for processing certain information (auditory processing, memory).

  • Frontal lobes: One of the four structural areas of the cerebral cortex, specialized for processing certain information (planning, decision-making, executive functions).

  • Split brain: A condition in which the hemispheres of the brain are separated, so information cannot be transferred from one hemisphere to the other, providing insights into hemispheric specialization.

Broca's area is a region in the frontal lobe of the dominant hemisphere (usually the left) of the brain with functions linked to speech production. Damage to Broca's area can lead to Broca's aphasia, a condition characterized by difficulty producing speech, although comprehension of language remains relatively intact.