AP Psychology - Unit 1.4 Brain Structures and Functions

Neuroplasticity/Brain Plasticity

• the brain’s ability to adapt and change to different circumstances

Phineas Gage

• survived a famous accident where a tampering rod shot through his skull

• he experienced severe personality changes

• his case study helped neuroscientists and psychologists to discover that the brain is composed of different areas and hemispheres that have specialized functions

Brain Lateralization

• the idea that each hemisphere of the brain is specialized for different neural functions or brain processes

Left Hemisphere of the Brain

specializes in:

• language

• logic

• reasoning/analysis

• science and math

Right Hemisphere of the Brain

specializes in:

• creativity

• imagination

• rhythm

• holistic thinking

• visual-spatial awareness

Lesioning

• destroying/damaging brain tissue

• can occur naturally (trauma or disease), during surgery, or experimentally

Autopsy

• dissecting the human body

• can help doctors/scientists confidently define the cause of death and give a proper diagnosis

Electroencephalogram (EEG)

• measures the waves of electrical activity sweeping across the brain’s surface

• electrodes are placed on the scalp 

• allows researchers to record electrical signals from neurons firing

• helps with sleep studies and seizure research

Functional MRI (fMRI)

• shows brain function as well as structure

• reveals the blood flow and, therefore, brain activity (active parts of the brain receive more blood flow)

Contralateral Organization

• right visual field is processed by the left hemisphere

• left visual field is processed by the right hemisphere

Spinal Cord

• enables chemical messages to travel between the brain and body

Brainstem

responsible for connecting the brain with the spinal cord and automatic survival  functions

located in the hindbrain division 

includes the:

• medulla oblongata

• pons

Medulla Oblongata

the brainstem’s base

located below the pons

controls autonomic/unconscious functions such as:

• heart rate

• breathing 

• digestion

• blood pressure

Pons

connects different parts of the nervous system, especially the cerebrum an the cerebellum 

play a huge role in sleep cycles and dreaming, particularly regulating REM sleep

• REM sleep: stands for Rapid Eye Movement; distinct sleep stage characterized by vivid dreaming, increase in neural activity, and rapid eye movement

Reticular Activating System (RAS)/Reticular Formation

• bundle of nerves that run through the brain stem

• plays a significant role in regulating arousal and consciousness as it helps control an individual’s circadian rhythm and general alertness

• neurons that make up the reticular activating system filter incoming sensory information from afferent neurons and alert the brain to important signals

Cerebellum

“little brain”

located at the base of the brain in the back

mainly controls muscle movement, balance, coordination, and posture

additionally, it controls some forms of procedural learning;

• procedural learning: a type of long-term memory that involves learning how to perform tasks through repetition and practice, often without conscious awareness

Cerebrum

• largest part of the brain

• split into two cerebral hemispheres

• enables an individual to speak, perceive, and think

Cerebral Cortex

• covers the cerebrum

• outer layer of the brain

• composed of grey matter

• divided into two hemispheres (left and right hemisphere) and is made up of four main lobes (frontal lobes, parietal lobes, occipital lobes, and temporal lobes)

Corpus Callosum

• thick band of neural fibers

• connects the cerebral hemispheres and allows them to communicate with one another

Frontal Lobes

located just behind the forehead

responsible for higher level thinking and executive functioning

help an individual do many things such as:

• produce and organize speech

• plan

• solve problems

• manage

• make decisions

• regulate attention

• control impulses

Prefrontal Cortex

located in the front of the frontal lobes

one of the last areas of the brain to fully develop

executive functioning

involved in:

• judgement

• planning

• foresight

• attention

• complex thought

Motor Cortex

• located in the back of the frontal lobes

• controls voluntary muscle movement

Motor Homunculus

• a diagram that visualizes the brain’s control over an individual’s movement

• shows how much space in the motor cortex is devoted to each part of the body

• complex areas like the hands and face take up more space

Broca’s Area

• located in the frontal lobes

• involved in speech production

• helps coordinate the muscle movements needed to speak, especially those related to the mouth, lips, and tongue

Broca’s Aphasia

• a condition where a person struggles to produce speech

• the individual will know what they want to say, but will have difficulty forming complete sentences

Parietal Lobes

located near the top and back part of the brain

responsible for processing sensory information and spatial awareness

• association areas: regions that help the brain organize and make sense of information from the different senses

Somatosensory Cortex

• part of the parietal lobes

• processes touch, pain, pressure, and temperature from the body and the senses

Sensory Homunculus

• a diagram that visualizes the amount of brain area that is dedicated towards specific body parts

• body parts like the hands and lips take up more space in the somatosensory cortex, because they are more sensitive parts of the body

Temporal Lobes

• located just above the ears

• processes sounds

• helps with language comprehension

• crucial for memory storage

Hippocampus

• a part of the limbic system

• plays a key role in forming new long-term memories, especially explicit memories (does NOT help store memories)

• controls learning and emotional regulation

Amygdala

• a part of the limbic system

• involved in emotion, especially fear and aggression

• helps an individual respond emotionally to intense situations

Auditory Cortex

• located in the temporal lobes

• processes what an individual hears

Wernicke’s Area

• located in the temporal lobes

• responsible for creating and comprehending language

Wernicke’s Aphasia

• a condition where an individual has difficulty comprehending spoken language

• an individual may be able to speak in sentences and phrases, but the words won’t make sense

Occipital Lobes

• located in the back of the brain

• processes and interprets visual information

Primary Visual Cortex

• located in the occipital lobes

• processes what an individual sees

Thalamus

• a part of the limbic system

• receives sensory information from an individual’s senses, except for smell

• send the sensory information to the right parts of the brain

• known as the sensory relay station

Hypothalmus

• a part of the limbic system

• helps maintain a stable internal environment (homeostasis) by balancing an individual’s hunger, thirst, body temperature, reward pathway, and sexual behavior

• regulates the endocrine system by signaling messages to the pituitary gland

Limbic System

located between the brainstem and the cerebral cortex

plays a major role in emotions, motivation, memory, and learning

composed of the:

• thalamus

• hypothalamus

• hippocampus

• amygdala

Pituitary Gland

• “master gland”

• releases hormones that affect physical development, growth, and metabolism

• secretes hormones that influence the other glands in the endocrine system

Forebrain

• 85% of the brain

• manages voluntary motor activities and complex cognitive activities

Midbrain

• connects the hindbrain with the forebrain

• relay station for auditory and visual information

Hindbrain

• “old brain”

• controls survival instincts and involuntary processes