Neurobiological basis of psychology
The NERVOUS SYSTEM is the body’s electrochemical communication circuitry, made up of billions of interconnected cells
Pathways of the nervous system
Sensory Input (Afferent Nerves) --> Integrated by the brain (Neural Networks) --> Motor Output (Efferent Nerves)
Divisions of the Nervous system
Central Nervous System
- Brain
- Spinal cord
Peripheral Nervous System
- Somatic Nervous System (voluntary movements)
- Autonomic Nervous System (involuntary movements)
- Sympathetic Nervous System (arouses/excites the body)
- Parasympathetic Nervous System (relaxes or calms the body)
Cell structure: Neuron (nerve cells that handle the process of information)
- Cell Body: contains the nucleus and it is responsible for the growth, maintenance, development of the cell
- Dendrites: receives information form other neurons towards the cell body
- Axons: carries information towards other neuron away from the cell body
- Terminal buttons: found in the ends of the axons. Contains synaptic vesicles that have neurotransmitters
Neurotransmitters: they either stimulate/excite other neurons to fire or they inhibit them or both. There are more than 50 neurotransmitters found in the human body. Drugs that interfere with neuro transmitters are called agonist (drugs that increase or mimics the neurotransmitters) and antagonist (those that blocks the effects of the transmitters)
a. Acetylcholine (Ach)
simulates firing of neuron
involved in the action of muscles, learning and memory
found in the CNS and PNS
Examples: venom/poison of a black widow = stimulates to make spasms
poison dart/tranquilizers = blocks the receptors for Ach, paralyzing the person
nicotine = stimulates the receptors
Alzheimer’s disease (Ach deficient)
b. GABA (gamma aminobutyric acid)
found in the CNS (1/3 of the brains synapse)
keeps many neurons from firing
controls the preciseness of the signals carried from 1 neuron to the other
low level of GABA = anxiety
valium increases inhibiting effect of GABA
c. Norepenipherine
usually inhibits firing of neurons BUT excites the heart muscles, intestines etc.
eg: stress stimulates the release norepenipherine
controls alertness
Too little of norepenipherine = depression; too much = manic states
d. Dopamine
mainly inhibits
helps control voluntary movement
affects sleep, mood, attention and learning
eg. Stimulants like cocaine/amphetamines produce excitement, alertness, decreased fatigue and increased motor activity
e. Serotonin
also inhibits
regulates sleep, mood, attention and learning
regulates sleep and wakefulness w/ acetylcholine and norepinepherine
low level of serotonin is associated with depression
PROZAC (antidepressant) increase the brain levels of serotonin
f. Endorphin
natural opiate
stimulates other neurons
protects the body from pain and elevates pleasure
eg. morphine - anesthesia
Levels of Organization of the Brain
I. Hindbrain
a. Medulla
When the spinal cord enters the skull
Controls breathing
Regulates reflexes
Allows us to maintain an upright
b. Cerebellum
rear of hindbrain, just above the medulla
rounded structure that are important in motor coordination
ex. Arm and leg movement.: playing the piano, playing
c. Pons
-bridge in the hindbrain
contains several fibers involved in sleep and arousal
2. Midbrain
located in between the hindbrain and forebrain
contains several nerve fibers that ascend and descend to connect higher and lower portions of the brain.
Relays information between the brain and eyes & ears.
Linked to our ability to attend to an object visually
a. Reticular Formation
collection of neurons involved in stereotyped patterns of behavior eg. Walking, sleep, turning to attend to a sudden noise.
b. Brain Stem.
-includes most of the hindbrain and midbrain (except the cerebellum)
- Connects the spinal cord until the reticular formation
- Most ancient part of the brain (500 Million yrs”)
- Clumps of cells that determine alertness and regulates basic survival functions ex. Breathing, heart beat, blood pressure.
3. Forebrain:
highest level of the human brain
a. Limbic System
-loosely connected of structures under the cerebral cortex
-important in memory and emotion
a.1. Amygdala (Latin for “almond” shape)
located at the base of the temporal lobe
involved in the discrimination of objects necessary for survival
Ex food, mates ,social rivals
neurons in the amygdala fires selectively to such stimuli
involved in emotional awareness and expression
DAMAGE: eat, fight or mates with inappropriate objects
a.2. Hippocampus
role in storage of memories
DAMAGE: Individuals do not retain new conscious memories after the damage
(note) Memories are not stored in the limbic system but determine what information should have a lasting neural trace in the cortex.
b. Thalamus
located on top of the brain stem in the central core of the brain.
sorts information and send it to the appropriate places in the forebrain for further information and integration
involved in sense receptors
also involved in sleep and wakefulness (with reticular formation)
Ex. cerebellum-àthalamusàmotor area (cerebral cortex)
c. Basal Ganglia
located above the thalamus, under the cerebral cortex
clusters of neurons
works with the cerebellum and cerebral cortex to control and coordinate voluntary movement
enables for habitual behavior
Ex. riding a bicycle, driving
DAMAGE: can cause unwanted movements
Ex. jerking of limbs
Or too little movement
Ex. like Parkinson’s disease
d. Hypothalamus
small forebrain structure below the thalamus
monitors three pleasurable activities:
1. eating
2. drinking
3. sex
involved in emotion, stress, rewards
sensitive to change in blood & neural output
Ex. Blood 1-2c = skin/sweat glands have circulation
Emotional State & Stress: How people handle stress
e. Cerebral cortex
highest region in the forebrain
most recently developed
involved in highest mental function: thinking/planning
convoluted
f. Lobes
f.1. Occipital lobe
- back of the head
- responds to visual stimulus
- connect to process info. On visual stimuli
ex. Color, shape, motion
Damage may cause blindness
f.2. Temporal lobe
- part of cerebral cortex above the ears
- involved in hearing, language, processing & memory
- connected to the limbic system
Damage: cannot retain experiences to long term memory
f.3. Frontal lobe
found in the cerebral cortex behind the for brain
involved in control of voluntary muscles, intelligence and personality
eg. Phineas Gage (Sept 13, 1848) prefrontal cortex (responsible for planning and monitoring/organizing thinking) was damaged.
f.4. Parietal lobe
located on top of the rear head
involved in registration of spatial location, attention and motor cortex
eg. Judging how far the buildings are
g. Cortexes
- Visual Cortex: vision and sight
- Auditory Cortex: hearing and sound
- Prefrontal Cortex: planning, reasoning
- Motor Cortex: voluntary movement
- Somatosensory: body sensation
- Association Cortices/Association Areas:
comprises 75% of the cerebral cortex and integrates information among the other cortex
(note) a damage to a specific part does not result in specific loss of a function (except for the language areas)
EXAMPLE:
Broca’s Area which is involved in speech production
Wernicke’s Area which is involved in comprehending language.
Cerebral Hemispheres:
Roger Sperry (1974) had an epileptic patient called ‘W.J.’ created the split brain theory:
Left Connected by the Corpus Callosum Right
Receives information from the Receives information from the the right side of the body left side of the body
Speech & grammar Appropriate use of language
Logic, mathematics Processes non-verbal info.
Processes verbal information Spatial reasoning, visual recognition, and emotional recognition
Pathways of the nervous system
Sensory Input (Afferent Nerves) --> Integrated by the brain (Neural Networks) --> Motor Output (Efferent Nerves)
Divisions of the Nervous system
Central Nervous System
- Brain
- Spinal cord
Peripheral Nervous System
- Somatic Nervous System (voluntary movements)
- Autonomic Nervous System (involuntary movements)
- Sympathetic Nervous System (arouses/excites the body)
- Parasympathetic Nervous System (relaxes or calms the body)
Cell structure: Neuron (nerve cells that handle the process of information)
- Cell Body: contains the nucleus and it is responsible for the growth, maintenance, development of the cell
- Dendrites: receives information form other neurons towards the cell body
- Axons: carries information towards other neuron away from the cell body
- Terminal buttons: found in the ends of the axons. Contains synaptic vesicles that have neurotransmitters
Neurotransmitters: they either stimulate/excite other neurons to fire or they inhibit them or both. There are more than 50 neurotransmitters found in the human body. Drugs that interfere with neuro transmitters are called agonist (drugs that increase or mimics the neurotransmitters) and antagonist (those that blocks the effects of the transmitters)
a. Acetylcholine (Ach)
simulates firing of neuron
involved in the action of muscles, learning and memory
found in the CNS and PNS
Examples: venom/poison of a black widow = stimulates to make spasms
poison dart/tranquilizers = blocks the receptors for Ach, paralyzing the person
nicotine = stimulates the receptors
Alzheimer’s disease (Ach deficient)
b. GABA (gamma aminobutyric acid)
found in the CNS (1/3 of the brains synapse)
keeps many neurons from firing
controls the preciseness of the signals carried from 1 neuron to the other
low level of GABA = anxiety
valium increases inhibiting effect of GABA
c. Norepenipherine
usually inhibits firing of neurons BUT excites the heart muscles, intestines etc.
eg: stress stimulates the release norepenipherine
controls alertness
Too little of norepenipherine = depression; too much = manic states
d. Dopamine
mainly inhibits
helps control voluntary movement
affects sleep, mood, attention and learning
eg. Stimulants like cocaine/amphetamines produce excitement, alertness, decreased fatigue and increased motor activity
e. Serotonin
also inhibits
regulates sleep, mood, attention and learning
regulates sleep and wakefulness w/ acetylcholine and norepinepherine
low level of serotonin is associated with depression
PROZAC (antidepressant) increase the brain levels of serotonin
f. Endorphin
natural opiate
stimulates other neurons
protects the body from pain and elevates pleasure
eg. morphine - anesthesia
Levels of Organization of the Brain
I. Hindbrain
a. Medulla
When the spinal cord enters the skull
Controls breathing
Regulates reflexes
Allows us to maintain an upright
b. Cerebellum
rear of hindbrain, just above the medulla
rounded structure that are important in motor coordination
ex. Arm and leg movement.: playing the piano, playing
c. Pons
-bridge in the hindbrain
contains several fibers involved in sleep and arousal
2. Midbrain
located in between the hindbrain and forebrain
contains several nerve fibers that ascend and descend to connect higher and lower portions of the brain.
Relays information between the brain and eyes & ears.
Linked to our ability to attend to an object visually
a. Reticular Formation
collection of neurons involved in stereotyped patterns of behavior eg. Walking, sleep, turning to attend to a sudden noise.
b. Brain Stem.
-includes most of the hindbrain and midbrain (except the cerebellum)
- Connects the spinal cord until the reticular formation
- Most ancient part of the brain (500 Million yrs”)
- Clumps of cells that determine alertness and regulates basic survival functions ex. Breathing, heart beat, blood pressure.
3. Forebrain:
highest level of the human brain
a. Limbic System
-loosely connected of structures under the cerebral cortex
-important in memory and emotion
a.1. Amygdala (Latin for “almond” shape)
located at the base of the temporal lobe
involved in the discrimination of objects necessary for survival
Ex food, mates ,social rivals
neurons in the amygdala fires selectively to such stimuli
involved in emotional awareness and expression
DAMAGE: eat, fight or mates with inappropriate objects
a.2. Hippocampus
role in storage of memories
DAMAGE: Individuals do not retain new conscious memories after the damage
(note) Memories are not stored in the limbic system but determine what information should have a lasting neural trace in the cortex.
b. Thalamus
located on top of the brain stem in the central core of the brain.
sorts information and send it to the appropriate places in the forebrain for further information and integration
involved in sense receptors
also involved in sleep and wakefulness (with reticular formation)
Ex. cerebellum-àthalamusàmotor area (cerebral cortex)
c. Basal Ganglia
located above the thalamus, under the cerebral cortex
clusters of neurons
works with the cerebellum and cerebral cortex to control and coordinate voluntary movement
enables for habitual behavior
Ex. riding a bicycle, driving
DAMAGE: can cause unwanted movements
Ex. jerking of limbs
Or too little movement
Ex. like Parkinson’s disease
d. Hypothalamus
small forebrain structure below the thalamus
monitors three pleasurable activities:
1. eating
2. drinking
3. sex
involved in emotion, stress, rewards
sensitive to change in blood & neural output
Ex. Blood 1-2c = skin/sweat glands have circulation
Emotional State & Stress: How people handle stress
e. Cerebral cortex
highest region in the forebrain
most recently developed
involved in highest mental function: thinking/planning
convoluted
f. Lobes
f.1. Occipital lobe
- back of the head
- responds to visual stimulus
- connect to process info. On visual stimuli
ex. Color, shape, motion
Damage may cause blindness
f.2. Temporal lobe
- part of cerebral cortex above the ears
- involved in hearing, language, processing & memory
- connected to the limbic system
Damage: cannot retain experiences to long term memory
f.3. Frontal lobe
found in the cerebral cortex behind the for brain
involved in control of voluntary muscles, intelligence and personality
eg. Phineas Gage (Sept 13, 1848) prefrontal cortex (responsible for planning and monitoring/organizing thinking) was damaged.
f.4. Parietal lobe
located on top of the rear head
involved in registration of spatial location, attention and motor cortex
eg. Judging how far the buildings are
g. Cortexes
- Visual Cortex: vision and sight
- Auditory Cortex: hearing and sound
- Prefrontal Cortex: planning, reasoning
- Motor Cortex: voluntary movement
- Somatosensory: body sensation
- Association Cortices/Association Areas:
comprises 75% of the cerebral cortex and integrates information among the other cortex
(note) a damage to a specific part does not result in specific loss of a function (except for the language areas)
EXAMPLE:
Broca’s Area which is involved in speech production
Wernicke’s Area which is involved in comprehending language.
Cerebral Hemispheres:
Roger Sperry (1974) had an epileptic patient called ‘W.J.’ created the split brain theory:
Left Connected by the Corpus Callosum Right
Receives information from the Receives information from the the right side of the body left side of the body
Speech & grammar Appropriate use of language
Logic, mathematics Processes non-verbal info.
Processes verbal information Spatial reasoning, visual recognition, and emotional recognition