AP PSYCHOLOGY UNIT #2: PART 1
Unit Two: Part 1 - Biological Bases of Behavior
==Terms:==
| Glial Cells (Glia) | Cells in the nervous system support, nourish, and protect neurons; they also play a role in learning, thinking, and memory |
|---|---|
| Refractory Period | In neural processing, a brief resting pause occurs after a neuron has fried; subsequent action potentials cannot occur until the axon returns to its resting state |
| Agonist | A molecule that increases the activity of a neurotransmitter |
| Antagonist | A molecule that inhibits it blocks the action of a neurotransmitter |
| Sensory (afferent) neurons | Neurons carry incoming information from the body’s tissues and sensory receptors to the brain and spinal cord |
| Motor (efferent) neurons | Neurons carry outgoing information from the brain and spinal cord to the muscles and glands |
| Interneurons | Neurons within the brain and spinal cord; communicate internally and process information between the sensory inputs and motor outputs |
| Adrenal Glands | A pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress |
| Pituitary Gland | The endocrine system's most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands |
| Thalamus | The brains sensory control center, located on top of the brainstem; directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla |
| Reticular Formation | A nerve network that travels through the brainstem into the thalamus and plays an important role in controlling arousal |
| Neurogenesis | The formation of new neurons |
| Blindsight | A condition in which a person can respond to a visual stimulus without consciously experiencing it |
==Parts of The Cell:==
- Dendrites (receive messages)
- Cell Body
- Axon (message travels across)
- Myelin Sheath (fatty tissue; allows for fast transmission)
- Terminal Branches
- Terminal Button (contains neurotransmitter)
- Synapse (cleft or gap)
- Neurotransmitters (Chemical Messengers)
==Neurotransmitters:==
- Chemical messengers
- It can be either excitatory or inhibitory
- Serotonin
- Dopamine
- Acetylcholine
- Endorphins
- Drugs can impact the amount released
- Agonists - excite
- Antagonists - inhibit
- Re-uptake (absorption of excess Neurotransmitters)
==Other Terms/Concepts:==
- Action Potential
- Electronic charged positive ions enter the axon and cause an “all or nothing” response
- The Axon section (sausage) becomes depolarized
- When they are stable it is known as Resting Potential
==Brain Research Techniques:==
- Recording/Neuro-imaging Techniques
| Technique | Function |
|---|---|
| Electrode Recording | Insert an electrode into a part of the brain and record neural firing |
| EEG | Measure overall brain electrical activity (measured in waves) |
| CT Scan | X-ray of the brain |
| MRI | Uses magnetic technology to get a picture of the brain’s soft tissue |
| fMRI | Uses magnetic technology and measures blood flow to active areas |
| PET Scan | Insert glucose into the patient, glucose goes to active areas of the brain (the brighter the color, the more neural activity) |
==Stimulation:==
- Using electrodes, magnets, or chemicals, you induce firing in a certain part of the brain
- Example: Penfield stimulated the temporal lobe of a human and they heard music
- Example: If you stimulate the Hypothalamus of a rat, it will not stop eating
==Lesion:==
- Cutting or burning of neural connections
- Example: A lesion of the hypothalamus will cause a rat to NEVER eat
- Example: Kluver and Bucey (1937) killed the temporal lobe of monkeys and they no longer showed any aggression
==The Cerebral Cortex:==
- The Cerebral Cortex is the thin layer on the top of your brain
- We can divide the Cerebral Cortex into 4 regions called Lobes:
| Name | Functions |
|---|---|
| Frontal Lobe (Motor Cortex) | Speech, muscle movement, planning, personality |
| Temporal Lobe (Sensory Cortex) | Primarily movement and sensations |
| Parietal Lobe (Auditory Cortex) | Primarily auditory |
| Occipital Lobe (Visual Cortex) | Primarily sight |
- Further Details
| Area | Result if Damaged |
|---|---|
| Broca’s Area (Left Frontal Lobe) | Someone with damage to this area will not be able to speak (Aphasia) |
| Wernicke’s Area (Left Temporal Lobe) | Someone with damage will not be able to understand/comprehend speech |
==The Hemispheres of The Brain:==
- Each hemisphere controls the OPPOSITE side of the body
- The two halves of the brain are known as Hemispheres
- The two hemispheres are connected by a large band of nerves known as the Corpus Callosum
| Hemisphere | Functions |
|---|---|
| Left Brain | logic, problem-solving, math, language, etc. |
| Right Brain | emotions, art, music, creativity, facial recognition |
==Split Brain Patients:==
- For reasons that are not completely known, severe epilepsy can be controlled by cutting the corpus callosum
- These patients (split-brain patients) have been of great interest to the world of Psychology because their hemispheres are no longer able to communicate
- Example:
- The left eye shows a picture of an object (so the image goes to the right hemisphere)
- The left hand is then able to point out that object in a “lineup”
- But…patient is frustrated because they do not understand how they know that
- Their left brain is speaking out because it does not know what was seen
- More Possible Effects of Split Brain Surgery:
| Effect | Explanation |
|---|---|
| Alien Hand Syndrome | Hands have a “mind of their own |
| Left Brain Rationalization | When an action is taken that was a product of the right brain, the left brain will make up a reason why it happened |
==Plasticity:==
- The brain's ability to change and take over functions of damaged parts
- For example - Someone born blind can have a heightened sense of hearing because the area normally used for seeing isn’t needed for that
==Lower Brain Structures:==
| Term | Function |
|---|---|
| Brainstem | Meeting place of brain and spinal cord |
| Medulla | Helps regulate heartbeat and breathing |
| Reticular Formation | Network of nerves within the Medulla that helps with stimulus filtration and communication between hemispheres |
| Thalamus | Receives info from senses (except smell) |
| Cerebellum | Coordinates voluntary movements |
==The Limbic System:==
- It is the emotional center of our brain
| Term | Function |
|---|---|
| Amygdala | Associated with aggression and fear |
| Hypothalamus | Regulates hunger, thirst, temperature, sexual |
| behavior (reward centers) | |
| Hippocampus | Memory |
==Additional Important Content:==
- The Endocrine System - Considered to be the “slower” chemical message system of the body
- Responsible for secreting hormones
- The two major glands involved in the Endocrine system are:
| Gland | Function |
|---|---|
| Adrenal Gland | Involved in fight or flight, provides an energy boost |
| Pituitary Gland | Involved in sexual behavior and function, controlled by the hypothalamus |
==The Nervous System:==
- Hiking in the woods, a bear jumps out in front of you
- What would happen to your body?
- What do you think, contemplate, etc.?
- When faced with a dangerous or stressful situation, our bodies generally prepare for Fight or Flight
- Our Nervous Systems will respond by reacting in specific ways that will prepare our bodies to act and then, ultimately, recover
==The Central and Peripheral Nervous Systems:==
| Term | Function |
|---|---|
| Central Nervous System | The primary connection between the brain and the body (consists of the brain and the spinal cord) |
| Peripheral Nervous System | Nerves extending from the CNS to the muscles, glands, and senses |
- There are three main nerve types:
| Term | Function |
|---|---|
| Sensory (Afferent) Neurons | nerves containing sensory information |
| Interneurons | nerves within CNS that connect the CNS and PNS |
| Motor (Efferent) Neurons | nerves connected to body tissue |
==Further Components of the Peripheral Nervous System:==
- Peripheral Nervous System has two parts:
| Term | Function |
|---|---|
| Somatic Nervous System | controls movements of skeletal muscles |
| Autonomic Nervous System | controls gland and internal organs |
- The Autonomic NS has two parts:
| Term | Function |
|---|---|
| Sympathetic Nervous System | prepares (arouses) us for defensive action |
| Parasympathetic Nervous System | conserves energy |