Comprehensive Notes on Physiological Psychology
Physiological/Biological Psychology
Physiological psychology explores how the nervous system interacts with the body to produce behavior and mental states.
It covers:
Brain control of movement
Regulation of eating
Hormone's role in behavior
Drug effects on memory and personality
Sleep and dreaming
Language functions
Neurological disorders
Experimentation often involves manipulating the brain and nervous system, frequently utilizing animal models to understand the neural basis of behavior.
Background History
Evolved from philosophical ideas about the mind-body connection.
Significant development occurred in the 19th century through scientific and experimental approaches.
Wilhelm Wundt integrated physiological methods into psychological research.
Behaviorists like John B. Watson and B.F. Skinner studied brain activity regulated behavior through controlled experiments.
Research in Physiological Psychology
Employs various research methods to correlate physiological processes with behavior:
Brain imaging
Neurophysiological recording
Pharmacological interventions
Psychophysiological measurements
Overlaps with related disciplines:
Neurobiology: Focuses on nervous system functions.
Psychopharmacology: Focuses on drug effects on behavior.
Psychophysiology: Focuses on physiological responses related to behavior.
Brain Imaging
Techniques used to visualize and map the brain's structure and function.
Provides insights into neural anatomy, brain activity, and changes related to neurological and psychiatric disorders.
Aids in diagnosis, treatment planning, and research.
Types of Brain Imaging
Magnetic Resonance Imaging (MRI)
Uses strong magnetic fields and radio waves to produce high-resolution, three-dimensional images of brain structures without ionizing radiation.
Most sensitive imaging test for brain anatomy.
Can be enhanced with contrast agents like gadolinium to improve image quality.
Computed Tomography (CT) Scan
Uses multiple X-ray beams from different angles to create cross-sectional images of the brain.
Used for rapid assessment of brain injuries and structural abnormalities.
Involves exposure to ionizing radiation.
Angiography
Involves injecting dye into blood vessels and taking X-rays to visualize cerebral blood vessels.
Useful for detecting vascular abnormalities.
Functional Magnetic Resonance Imaging (fMRI)
Detects changes in blood oxygenation and flow that occur in response to neural activity.
Provides both anatomical and functional information.
Shows which brain areas are active during specific tasks or at rest.
Positron Emission Tomography (PET)
Uses radioactive tracers injected or inhaled to measure metabolic activity, such as glucose or oxygen use in the brain.
Can identify specific neurotransmitter receptors using radiolabeled ligands.
Magnetoencephalography (MEG)
Measures magnetic fields produced by neural electrical activity.
Provides functional data with high temporal and better spatial resolution than EEG.
Electroencephalography (EEG)
Records electrical activity of the brain via electrodes on the scalp.
Offers excellent temporal resolution of neural activity but with limited spatial resolution.
Widely used in research and clinical settings.
Interesting Facts About the Human Brain
Humans use all of their brain, not just 10%.
The brain can survive 5-6 minutes without oxygen.
While awake, the brain generates between 10 and 23 watts of power which can be expressed as .
Headaches are caused by a chemical reaction combined with muscle and nerve activity in the neck and head.
What is the Brain?
The brain is a complex organ that controls:
Thought
Memory
Emotion
Touch
Motor skills
Vision
Breathing
Temperature
Hunger
Every process that regulates our body.
Together with the spinal cord, it makes up the central nervous system (CNS).
Weighs about 3 pounds in the average adult and is about 60% fat; the remaining 40% is a combination of water, protein, carbohydrates, and salts.
Contains blood vessels and nerves, including neurons and glial cells, but is not a muscle itself.
Gray and White Matter of the Brain
Two different regions of the central nervous system.
In the brain:
Gray matter: darker, outer portion composed of neuron somas.
White matter: lighter, inner section underneath composed of axons wrapped in myelin.
In the spinal cord, the order is reversed.
Gray matter processes and interprets information.
White matter transmits information to other parts of the nervous system.
Brain Signals
The brain sends and receives chemical and electrical signals.
Different signals control different processes.
The central nervous system relies on billions of neurons (nerve cells).
Brain Coverings: Meninges
Three layers of protective covering surround the brain and the spinal cord.
Dura mater: outermost layer, thick and tough, includes two layers: the periosteal layer (lines the inner dome of the skull) and the meningeal layer (below that). Spaces between the layers allow for blood flow to the brain.
Arachnoid mater: thin, weblike layer of connective tissue without nerves or blood vessels. Below it is the cerebrospinal fluid (CSF), which cushions the entire central nervous system and continually circulates to remove impurities.
Pia mater: thin membrane that hugs the surface of the brain and is rich with veins and arteries.
Main Parts of the Brain and Their Functions
Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe
Cerebellum
Brain stem
Frontal Lobe
Largest lobe, located in the front of the head.
Involved in personality characteristics, decision-making, and movement.
Recognition of smell.
Contains Broca’s area, which is associated with speech ability.
Parietal Lobe
Middle part of the brain.
Helps identify objects and understand spatial relationships.
Involved in interpreting pain and touch in the body.
Houses Wernicke’s area, which helps the brain understand spoken language.
Occipital Lobe
Back part of the brain that is involved with vision.
Temporal Lobe
Sides of the brain.
Involved in auditory processing, language comprehension, memory, and certain aspects of visual perception.
Cerebellum
Located at the back of the head, below the temporal and occipital lobes and above the brainstem.
Coordinates voluntary muscle movements and maintains posture, balance, and equilibrium.
Studies are exploring its roles in thought, emotions, and social behavior, as well as its possible involvement in addiction, autism, and schizophrenia.
Brainstem
Connects the cerebrum with the spinal cord.
Includes the midbrain, the pons, and the medulla.
Cerebrum
Comprises gray matter (the cerebral cortex) and white matter at its center.
Largest part of the brain.
Initiates and coordinates movement and regulates temperature.
Enables speech, judgment, thinking and reasoning, problem-solving, emotions, and learning.
Relates to vision, hearing, touch, and other senses.
What the Cerebrum Does
Handles much of the brain’s “conscious” actions.
Responsible for elements that require thinking:
Five senses: Manages and processes sensory input.
Language: Controls the ability to read, write, and speak.
Working memory: Short-term memory.
Behavior and personality: The frontal lobe manages personality and behavior, acting as a filter.
Movement: Sends signals to muscles.
Learning, logic, and reasoning: Different areas work together to learn new skills or solve problems.
Frontal Lobe Functions
Primary motor cortex: Voluntary movements
Premotor & supplementary motor cortex: Planning, sequence, & execution of movements.
Frontal eye fields: Voluntary eye movements.
Prefrontal cortex: Memory, learning, personality/behavior, decision-making, motor planning.
Broca’s area: Speech production.
Parietal Lobe Functions
Primary somatosensory cortex: Awareness of somatic sensations (senses)
Somatosensory association cortex: Analyze & recognize somatic senses.
Posterior association area: Multimodal association area, interpretation of visual, auditory sensory.
Occipital Lobe Functions
Primary visual cortex: Awareness of visual information
Visual association cortex: Analyze & recognize visual information
Temporal Lobe Functions
Primary auditory cortex: Awareness of sound (pitch, frequency, location)
Auditory association cortex: Analyze & recognize sounds.
Wernicke's area: Language comprehension (written/verbal)
Primary olfactory cortex: Awareness of smell.
Cerebellum
Located at the back of the head, below the temporal and occipital lobes and above the brainstem.
Like the cerebral cortex, it has two hemispheres.
The outer portion contains neurons, and the inner area communicates with the cerebral cortex.
Coordinates voluntary muscle movements and maintains posture, balance, and equilibrium.
New studies are exploring its roles in thought, emotions, and social behavior, as well as its possible involvement in addiction, autism, and schizophrenia.
Brainstem
Connects the cerebrum with the spinal cord.
Includes the midbrain, the pons, and the medulla.
Midbrain: Involved in motor control (eye movements) and processes visual and auditory information.
Pons: Helps coordinate movements of the face and eyes, facial sensations, hearing, and balance.
Medulla Oblongata: Regulates breathing, heartbeat, blood pressure, and swallowing.
Limbic System
A group of brain structures that regulate emotion, memory, motivation, and behavior.
Includes the amygdala, hippocampus, hypothalamus, cingulate gyrus, and basal ganglia.
These structures work together to help form memories, respond to threats, and process emotions.
Closely linked to mental health conditions like anxiety, PTSD, depression, and addiction.
Understanding how it functions can explain why we react emotionally—and how those reactions can be managed or treated.
Functions of the Limbic System
Emotions – especially fear, anger, and pleasure
Memory formation – turning experiences into lasting memories
Motivation and behavior – driving hunger, reward-seeking, and social bonding
Physiological responses – like heart rate, stress, and the fight-or-flight response
This system ties together emotional and instinctive reactions that keep us safe and help us navigate the world.
Parts of the Limbic System
Hippocampus
Converts short-term experiences into long-term memories, especially episodic and spatial memory.
Supports learning, especially when emotions are involved.
Works closely with the prefrontal cortex to help recall past experiences for decision-making.
Has strong connections with the amygdala, linking emotions to memories.
One of the few brain areas where neurogenesis continues into adulthood, possibly supporting emotional resilience.
Clinical insight: Hippocampal damage is linked to amnesia, disorientation, and memory loss and plays a role in Alzheimer’s disease, dementia, and post-stroke cognitive decline.
Amygdala
Detects emotional stimuli and triggers rapid responses, especially for fear, anger, and threat detection.
Attaches emotional salience to memories, helping prioritize what we remember.
Plays a key role in fear learning, especially through repetition of threatening experiences.
Connects to the hypothalamus and autonomic nervous system, initiating the body’s fight-or-flight response.
Also involved in social behavior, such as recognizing facial expressions and emotional cues.
Clinical view: Abnormal amygdala function is linked to anxiety disorders, PTSD, borderline personality disorder, and even psychopathy.
Hypothalamus
Maintains homeostasis by controlling hunger, thirst, sleep, body temperature, and circadian rhythms.
Regulates hormonal responses by signaling the pituitary gland, acting as the bridge between the brain and endocrine system.
Plays a critical role in sexual behavior, maternal bonding, and aggression.
Initiates the stress response by activating the hypothalamic-pituitary-adrenal (HPA) axis.
Clinical relevance: Chronic dysregulation is associated with mood disorders, eating disorders, and chronic stress syndromes. Overactivity can lead to anxiety; underactivity can contribute to depression.
Cingulate Gyrus
Involved in regulating emotions, especially in response to pain or distress.
Helps monitor conflict and decision-making, particularly when there’s emotional uncertainty.
Integrates emotional processing with motor planning and autonomic responses.
Plays a role in empathy, social interaction, and predicting others’ behavior.
Clinical applications: Structural or functional changes are linked to OCD, depression, schizophrenia, and ADHD. Anterior cingulate dysfunction is often implicated in poor emotional regulation and reduced motivation.
Basal Ganglia (Limbic Region)
Although often associated with movement, the limbic areas (especially the nucleus accumbens) are deeply involved in emotion, reward, and habit formation.
Plays a central role in dopamine-based reinforcement learning, driving behaviors linked to pleasure and motivation.
Connects emotional experiences to goal-directed behavior, helping form routines and habits.
Mental health link: Dysfunction in this region is implicated in addiction, compulsive behaviors, bipolar disorder, and Parkinson’s disease, where both movement and motivation are affected.
Importance of the Limbic System
Works closely with other parts of the brain to shape our thoughts, emotions, and behaviors.
Key relationship with the prefrontal cortex regulates emotional responses, allowing us to pause and think before reacting.
The brain stem also interacts with the limbic system, supporting automatic responses like heart rate and breathing during emotional arousal.
These pathways explain why strong emotions can override logic and why emotionally charged memories are so vivid and long-lasting.