Brain Research Methods

Brain Research Methods

• Early historical approaches to studying the brain relied on subjective data not supported by evidence
• Modern approaches use empirical evidence to understand the links between brain and behavior
• Key sources of knowledge include case studies, autopsies, and surgical/non-surgical procedures

Case Studies

• In-depth investigations of a single person or group of people that involve gathering descriptive data via observation, questionnaires, and interviews
• Phineas Gage's case (1848) involved a metal bar piercing his frontal lobe, changing his personality and providing information about its role in personality
• Henry Molaison underwent surgery removing part of his brain (medial temporal lobe) to treat epilepsy. He developed anterograde amnesia, which impacted the understanding on learning and memory.

Autopsies

• Surgical dissections performed on deceased persons to study their health conditions, determine cause of death, and study human physiology, anatomy, function, and behavior
• Paul Broca's autopsy of "Patient Tan" who had language difficulties led to discovery of Broca's area and its role in language production

Surgical Operations

• Live brain surgery helps scientists understand brain function by observing differences in patients before and after operations

Egas Moniz and Lobotomies

• Egas Moniz performed lobotomies by severing connections in the frontal lobe, often calming patients but with negative effects like lack of empathy and reduced emotional responses
• Procedure widely used (1930s-1950s) but considered unethical and illegal today. Still provided information on the frontal lobe.

Sperry and Gazzaniga and Split-Brain Surgeries

• Treated epileptic patients by severing the corpus callosum
• Led to the discovery that the left hemisphere is responsible for verbal tasks and the right for non-verbal tasks

Non-Surgical Operations

• Technological advancements allow study of brain structure and function without invasive surgery

Electrical Brain Stimulation (EBS)

• Involves inserting or placing an electrified wire on specific brain areas to initiate or block bodily responses which allows mapping of brain

Brain Mapping

• A non-invasive technique that measures electrical activity in the form of brain waves through the surface of the head using electrodes on the scalp to identify problem areas

Neuroimaging

• Non-invasive techniques to obtain brain images for diagnosing diseases and understanding brain function

Computerized Tomography (CT)

• Uses a series of X-rays scan brain from various angles to form 2D images
• Advantages: Relatively safe/cost effective and provides clear 2D images to identify damage from brain tumors and stroke
• Disadvantages: Lacks detailed images and doesn't provide behavioral and mental process info, radiation used

Positron Emission Tomography (PET)

• Measures blood flow volume and location by tracking radioactive glucose for color-coded images of activity levels in parts of the brain
• Advantages: Provides info about structural function during tasks, diagnoses dementia/tumors, can be used on people with medical devices
• Disadvantages: Abnormality can't be seen and damage to brain tissues can't be assessed

Magnetic Resonance Imaging (MRI)

• Utilizes magnetic fields/radiowaves to produce detailed 3D images
• Advantage: Harmless unlike Xrays - Disadvantage: Very expensive

Functional Magnetic Resonance Imaging (fMRI)

• Records oxygen levels to create high-quality images that reveal activity in certain regions of the brain

Brain Structures

• The brain contains the hndbrain, midbrain and forebrain

Hindbrain

• Located at the base of the skull
• Linked to the spinal cord to help the body function and survive
• Consists of cerebellum, pons and medulla

Medulla

• Long stem structure located at the lowest part of the brain
• Sends messages between the spinal cord and higher parts of the brain.
• Controls breathing, blood pressure, heart rate, swallowing, digestion, sneezing and vomiting

Pons

• The structure of the brainstem located above the medulla
• Connects cerebellum, cerebral cortex, pathways for motor movement
• Affects breathing, sleep, arousal, rapid eye movement, facial expressions

Cerebellum

• Major structure of the hindbrain at the base of the brain
• Coordinates voluntary movements, maintaining balance and posture, speech and vision

Midbrain

• Located between the hindbrain and the forebrain
• Key role movement, processing visual information, sleep-wake cycle, regulating temperature, contains rericular formation

Reticular Formation

• Network of neurons within the hindbrain and midbrain, filters sensory data to determine which stimuli reach conscious awareness

Forebrain

• Encompasses most visible portions
• Includes cerebral cortex, amygdala, hypothalamus, thalamus
• Responsible movement, sensory interpretation, language, personality

Cerebrum

• Largest part of the forebrain. Higher function process of reasoning.
• Includes voluntary movement, personality, emotions, touch, vision and hearing
• It has a cerebral cortex and 2 hemispheres

Corpus Callosum

• Connects the left and right cerebral cortex that are mirror images of each other

Cerebral Cortex

• Outer portion of the brain. Divided in left and right hemisphere

Hypothalamus

• Small structure - controls survical actions like sleep, thirst, hunger
• It helps regulate the endocrine system to ensure that the body's internal processes

Thalamus

• Act as brain control center for center sensory

Cerebral Cortex Structure/Role

• Outer brain region made of 3 parts
• Involved in higher order process
• Important in how we interact in the world

Cerebral Cortex Lobes

• Two hemispheres divided into 4 lobes: frontal, parietal, occipital and temportal

Frontal Lobe

• Located near front of the head
• Higher cognitive function such as movement behavior

Prefrontal Cortex

• Planning skills, reasoning, problem solving

Premotor Cortex

• Controls motor sequence

Primary Motor Cortex

• Resposible for body movement and motor cortices

Parietal Lobe

• Receives process bodily senstations

Primary Somatosensory Cortex

• Processes sensory information

Occipital Lobe

• Is located at the back of the head and interpets information from eyes

Temporal Lobe

• Located along sides of brain responsible precessing auditory information

Cerebral Cortex Association areas

• Help to integrate motor movement and sensory skills

Broca's Area

• Coordination for muscle movement

Hemispheres

• Divided two cerebral hemispheres the right and left

Hemispheric Specification

• Different roles dependent on behaviors
• Example primary motor cortex controls the rightside

Lateralized

• Most functions dont occurs in both side

Corpus Collosum

• Bundler of nerve bundles that separates the brain

Brain Plasticity

• Brain's ability to adapt with experiences

Neuroplasticity

• Composed of neuros and plasticity

Structure Plasticity

• Changing response of learning and experiences

Function Plasticity

• To control where function is to control damage
• Requires ability of brain to create new pathways

Nuero Plasticity

• Brain will adapt to damage and overcome a loss of function

Social impacts

• Can prevent someone form being able to interact socially

Abis

• Damage to help can be hard life changes

Chronic Traumatic Encephalopathy

• Concussions with headaches

CTE Symptoms

• Problems with thinking, mood regulation, and behavioral processes