BBB - The Brain: Neuroplasticity and Tools of Discovery Lesson

Learning Targets:

  • Describe the relationship between different brain structures and their influence on behavior and mental processes.
  • Discuss the reasons why human biology is important to psychologists.
  • Explain the combined role of biology and personal experiences in facilitating neuroplasticity.
  • Identify and evaluate various methods used to study how the brain is connected to behavior and mental processes.

Courtesy of the AP psychology course and exam description, effective fall 2024. (n.d.). Links to an external site.

 

The Importance of Human Biology in Psychology

The Brain

Our brain serves as the central command center of our bodies, governing our thoughts, emotions, and behaviors. Weighing in at around three pounds, the brain accounts for 2% of our body weight and consumes 20% of our oxygen while at rest. Comprising billions of neurons and glial cells, the brain forms a complex network of neural pathways crucial for our functioning, all protected by the sturdy fortress of our skull.

Studying the brain has always been challenging due to its intricate nature and safeguarding mechanisms. Historical methods like case studies of brain-damaged individuals and exceptionally skilled individuals have shed light on brain function, though their generalizability is limited. Today, modern research aims to offer foundational knowledgeIllustrated example of Phrenology about the brain's organization and operation, building upon centuries of neurological exploration.

Throughout history, viewpoints on the brain's function have evolved, from Hippocrates' recognition of the brain as the seat of the mind to Franz Gall's phrenology approach. Gall's work in phrenology was controversial and has since been discredited, mainly in modern neuroscience. However, his contributions were significant in the history of psychology as they sparked interest in the idea that different brain regions might be responsible for specific functions. This laid the groundwork for later neuroscientific research that would eventually lead to our current understanding of the brain's complex organization and function.

Contemporary biological psychologists now integrate biological, genetic, neural, hormonal, and psychological perspectives to understand human behavior within the complex biopsychosocial system. By examining the interactions between these systems, scientists can unravel the intricate mechanisms shaping our thoughts and actions over time, highlighting the interdisciplinary nature of psychology's study of human biology.

Behavioral Or Mental Processes Biological Influences : Inherited traits by genetics random genetic variations caused by gene replication Natural selection of traits for their adaptability Genes that adjust to environmental factors Psychological Influences fears and expectations that are acquired through learning. Emotional reactions How we process information and interpret our perceptions Socio-cultural influences Impact the presence of other people expectations set by culture society and family Influences from peers and other groups Powerful role models such as those seen in the media

Understanding Neuroplasticity: The Influence of Biology and Personal Experiences

Neuroplasticity, the brain's incredible ability to adapt and change, is influenced by genetics and personal experiences. Imagine the brain as a garden, where pathways are constantly being formed and pruned based on what we encounter in our lives. For example, when someone learns a new skill, like playing an instrument, the brain creates new connections and strengthens existing ones. This phenomenon showcases how our daily experiences actively shape the structure of our brains. Through practice and exposure to new challenges, we sculpt our brains, highlighting this remarkable organ's ongoing evolution and adaptability. Neuroplasticity underscores the uniqueness and potential for growth within each individual, demonstrating the extraordinary capabilities of the human brain.

Ways to Study the Brain: Accidents and Lesions

Image of Phineas Gage and the injuries to his brainAccidents

Sometimes, the brain becomes damaged, giving us a unique opportunity to study the brain. The most famous case study occurred on September 13, 1848, and involved Phineas Gage. Phineas Gage was a mild-mannered railroad worker involved in an accident. A four-foot, thirteen-pound iron pole shot through his head just under his left eye and came out the top. Miraculously, Phineas fully physically recovered. However, his personality changed forever.

Dr. John Harlow attended Phineas right after the accident and during recovery. He noted that before the accident, Phineas had been described as friendly, competent, and respectful. Afterward, he was described as stubborn, ill-tempered, and profane. Based on this case study, the idea that our frontal lobes were responsible for socio-emotional behavior, reasoning ability, thinking and planning, and decision-making came to fruition.

Lesions and Lobotomy

A lesion is the destruction or removal of part of the brain. Researchers study the effects of destroying parts of the brain on behavior and functioning. When parts of the brain are altered, destroyed, or removed, the effects are observed, providing useful information on what different brain parts do.

During the 1900s, doctors commonly performed frontal lobotomies (A frontal lobotomy involves cutting the connections to and from the prefrontal cortex, resulting in major personality changes.) on mental patients to change their personalities and alleviate their illness. This procedure was commonly performed on patients suffering from schizophrenia, depression, anxiety, and nuisance behavior. Unfortunately, these procedures were often done under less-than-ideal conditions outside of an operating room, with no anesthesia, and without the service of a surgeon.

Ways to Study the Brain: Brain Scans

Brain scans are a less invasive way to study the brain. No longer are researchers waiting for accidents to happen or going out and damaging or lesioning the brain. Brain scans electrically, chemically, and magnetically stimulate parts of the brain and record the effects.

Complete the Types of Brain Scans activity below:

There are some limitations to consider when using brain scans. The limited amount of equipment available and the excessive cost are other factors. Additionally, because of the small number of scans produced, it is difficult to generalize. Human behavior is so complex, and brain scans only provide a simple snapshot of behavior.

Photograph of Roger_Wolcott_SperryWhen we do use brain scans, it is essential to read the description and results carefully and be sure that you understand what is being measured. Providing a comparison scan is also essential to know what you are looking for and how it compares to what is considered "normal".

Split-Brain

Roger Sperry was an American neuropsychologist who significantly contributed to our understanding of the brain and its functions. He is best known for his research on split-brain patients, which showed that the brain's two hemispheres are specialized for different functions, a phenomenon known as brain lateralization. Through his experiments, Sperry demonstrated that the brain's left hemisphere is specialized for language processing and analytical reasoning. In contrast, the right hemisphere specializes in spatial perception, visual imagery, and holistic thinking. His work had significant implications for our understanding of brain plasticity and continues to influence the field of neuropsychology today.

 

 

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