Biology of the Mind Flashcards
Biopsychology.
- Scientific study of the
biology of mind and
behavior
Neurons
- Receive and send
electrochemical signals. - Approx. 100 billon
neurons in the brain. - Approx. 100 trillion
connections between
them.
Two main divisions. (Nervous System)
- Central Nervous System
(CNS). - Peripheral Nervous
System (PNS).
CNS.
- Brain.
- Spinal cord.
PNS.
- All nerves outside of the
brain and spinal cord. - Composed of two
divisions: somatic
nervous system and
autonomic nervous
system.
Somatic Nervous
System
- Afferent nerves carry
sensory signals from skin,
sensory organs, skeletal
muscles, and joints to the
CNS. - Efferent nerves carry
motor signals from the
CNS to the muscles.
Controls voluntary
movement.
Autonomic Nervous System
- Afferent nerves carry
sensory signals from the
internal organs to the
CNS. - Efferent nerves carry
automatic motor signals
from the CNS to the
internal organs. Controls
automatic movements
(e.g., heart rate,
digestion). - The ANS is divided into
the Sympathetic and
Parasympathetic
nervous system.
Sympathetic Nervous
System.
- Increases arousal and
energy. - Activates the fight-orflight response (e.g.,
release of stress
hormones, increased
respiration, increased
heartrate, slows
digestion, increased
blood flow to extremities,
etc.).
Parasympathetic
Nervous System.
- Conserves energy.
- Activates the rest-anddigest system.
- Actions tend to be in
opposition to those of the
sympathetic nervous
system.
Meninges.
Protect Brain and spinal cord
Meninges. Consists of
three layers.
1. Dura mater.
2. Arachnoid membrane.
- Subarachnoid space.
3. Pia mater.
Cerebrospinal fluid
(CSF).
- Clear fluid.
- Protects brain.
- Supports brain.
- Provides the brain with
necessary nutrients. - Helps clean the brain.
- Located in the
subarachnoid space (of
the Meninges), the
central canal of the
spinal cord (hollow canal
that runs the length of
the spinal cord), and the
cerebral ventricles of
the brain (four hollow
chambers in the brain).
Blood Brain Barrier
Protective barrier
between the brain and
the cerebral blood
vessels.
The endothelial cells of
the cerebral blood vessels
are squeezed tightly
together to form tight
junctions.
Tight junctions allow
for the passage of:
- small, uncharged
molecules. - fat-soluble molecules.
Tight junctions
prevent the passage
of:
- large molecules.
- proteins.
- charged molecules.
Three general
divisions of the brain.
- Forebrain.
- Midbrain.
- Hindbrain.
Medulla.
- Lowest part of brain
stem. - Regulates fundamental
life systems (e.g.,
breathing, heart rate). - Regulates reflexes (e.g.,
swallowing, vomiting).
Reticular formation.
- Tract of nerves that
traverses the center of
the brain stem from the
medulla to the midbrain. - Regulates arousal.
- Many other roles (e.g.,
sleep-wake cycle,
selective attention,
muscle tone
maintenance).
Pons.
- Contains tracts of the
reticular formation. - Regulates sleep-wake
cycle. - May play a role in
dreaming.
Cerebellum.
- Regulates motor
coordination and balance. - Also plays a role in
higher cognitive functions
(e.g., attention, planning,
learning, language,
decision making,
memory, moral
judgements, visual
perception). - Contains approx. 70% of
all neurons in the brain.
Midbrain
Two main divisions of the
midbrain:
- Tectum. (Divisions of the mid Brain)
- Processes visual and
auditory information. - Automatically directs
the body towards or away from the sensory stimuli
- Tegmentum. (Divisions of the mid Brain)
- Movement.
- Contains the substantia
nigra. The substantia
nigra contains dopamineproducing neurons that
supply dopamine to other
brain regions to facilitate
movement.
Parkinson’s
disease
e is caused by the
death of these dopamine producing neurons in the substantia nigra.
Forebrain
The forebrain controls the
most complex functions.
The forebrain can be
divided into the cerebral
cortex and subcortical
structures (i.e.,
structures below the
cerebral cortex).
The cerebral cortex
the
outermost layer of the
forebrain. It is often
referred to as grey
matter. The layer
beneath the cerebral
cortex is known as white
matter.
longitudinal fissure
Separates the left and right cerebral
hemispheres
Although the
hemispheres are
separated by the
longitudinal fissure, they
remain connected to each
other by the corpus callosum
.
The central sulcus and
the lateral fissure
divide
the cortex into four lobes:
the frontal lobe, the
parietal lobe, the
temporal lobe, and the
occipital lobe.
The Frontal Lobe
The frontal lobe contains
the prefrontal cortex and
the primary motor cortex.
Primary motor cortex.
- The left primary motor
cortex controls the right
side of the body, and the
right primary motor
cortex controls the left
side of the body. - Different areas of the
primary motor cortex are
responsible for controlling
different body parts. See
the diagram on the
PowerPoint for the
mapping of the body
across the motor cortex. - Body parts that require
more fine motor
movement (e.g., fingers
and hands) have more
cortex dedicated to them
than body parts that
require less (e.g., elbow).
Prefrontal Cortex.
- Responsible for our
highest cognitive
functions (e.g., planning,
decision making,
reasoning, language, and
emotional and behavioral
regulation).
Broca’s area.
speech production.
People with damage to
the brain area in and
around Broca’s area
experience Broca’s
Aphasia (i.e., expressive
aphasia). People with
Broca’s Aphasia have
difficulty producing
speech but can
understand speech. Their
speech will be meaningful
Prefrontal cortex
influences
personality
and emotional
regulation.
The Parietal Lobe
Contain the Primary
Somatosensory Cortex.
- this area is responsible
for processing tactile
sensations.
- Different areas of the
somatosensory cortex
receive information from
different body parts.
- Body parts that are
more sensitive have more
area of somatosensory
cortex dedicated to them.
Proprioception.
The sense of the positioning of our body
parts.
- The somatosensory
cortex allows for my
sense of proprioception
by processing information
about muscle tension.
Visual-spatial
information.
The parietal lobe is
responsible for processing
information about the
locations of objects in
space (e.g., where a cup
is located on a table
relative to my distance
from the table).
- The parietal lobe
integrates proprioception
information with visualspatial information to
allow us to interact
smoothly with objects in
space (e.g., reaching out
and grabbing the cup).
Damage to the Parietal
Lobe.
- Difficult reaching for and
grabbing an object (e.g.,
reaching past the cup or
grabbing too strongly). - Astereogonosia (i.e.,
inability to recognize
objects by touch alone). - Asomatognosia (i.e.,
inability to recognize that
a body part belongs to
you). - Contralateral Neglect
(i.e., inability to attend to
stimuli on one side of
space). Typically, the
result of damage to the
right parietal lobe and
people no longer attend
to stimuli on the left side
of space. Not a problem
with vision but a problem with attention
Occipital Lobe
Contains the Primary
Visual Cortex.
Damage to the primary
visual cortex
can result in
cortical blindness.
Cortical blindness can be
complete or localized to
an area in visual space.
People who are cortical
blind have normal eye
function but no conscious
visual perception.
- People with complete
cortical blindness are
unable to generate visual
images.
Temporal Lobe
Contains the Primary
Auditory Cortex.
Contains Wernicke’s
area.
- Left temporal lobe of
most people.
- Plays a role in
understanding language.
- Damage to Wernicke’s
area can cause
Wernicke’s aphasia.
People with Wernicke’s
aphasia have difficulty
understanding language.
Although their speech will
have normal pace and
include grammatical
elements, it will often not
make any sense (e.g.,
word salad, gibberish).
Damage to the inferior
temporal lobe can result
in visual agnosia (i.e.,
inability to recognize
objects).
Prosopagnosia.
- Inability to recognize
faces.
- Caused by damage to
the fusiform face area in the temporal lobe.
Subcortical Structures:
The Basal Ganglia
The basal ganglia are
clusters of neurons
that function together
as a system.
- Caudate Nucleus.
- Putamen.
- Globus Pallidus.
- Nucleus Accumbens.
Many of the basal
ganglia play an
important role in
movement.
- The ability to initiate
desired movements and
inhibit undesired
movements. - The movement function
of the basal ganglia is
dependent on a supply of
dopamine from the
Substantia Nigra (a
midbrain structure).
People with Parkinson’s
disease experience a
loss of dopamine
producing neurons in the
Substantia Nigra.
Nucleus Accumbens. - Dopamine activity in the
nucleus accumbens
influences motivation and
reward (e.g., pleasurable
experiences).
Subcortical Structures:
Thalamus
Two-lobed structure
that acts a sensory
relay station for all
sensory modalities
except smell.
Smell has its own private
relay station called the
olfactory bulb.
Subcortical Structures:
Hypothalamus
Regulates biological
drives (e.g., hunger,
sleep, sex, and thirst).
Contains the biological
clock that regulates
sleep-wake cycles.
Controls Autonomic
Nervous System.
Who’s the boss!
- Hypothalamus controls
the pituitary gland (i.e.,
an endocrine gland
responsible for releasing
hormones that travel in
the blood influencing
organs and other glands
throughout the body).
- So-called Master
Gland.
Subcortical Structures:
The Limbic System
For the sake of this class,
we listed the
hypothalamus, thalamus,
amygdala, and
hippocampus as
structures of the limbic
system.
The limbic system has
been termed by some as
the emotional brain.
- Several concerns about
the use of the term
Limbic System.
Subcortical Structures:
Amygdala
Important role in emotion,
particularly fear.
- Appraises a stimulus as
a threat or not.
Subcortical Structures:
Hippocampus
Important role in the
formation of new
memories.
- Damage to the
hippocampus can impair
memory formation (e.g.,
H.M).
- Spatial memories
(e.g., the Morris Water
Maze and rats).
Lateralization
Some brain abilities are
localized to a specific
hemisphere.
- Language skills are
localized to the left
hemisphere in most
people (e.g., Broca’s area
and Wernicke’s area).
