Chapter 2 reviewer
COGNITIVE PSYCHOLOGY CHAPTER 2:Cognitive Neuroscience
CHAPTER OUTLINE
Cognition in the Brain: The Anatomy and Mechanisms of the
Brain
• Gross Anatomy of the Brain
▪ Forebrain
▪ Midbrain
▪ Hindbrain
• Cerebral Cortex and Localization of Function
▪ Hemispheric specialization
▪ Lobes of the cerebral Hemisphere
Viewing the Structures and Functions of the Brain
• Postmortem Studies
• Studying Live Nonhuman Animals
• Studying Live Animals
▪ Electrical Recordings
▪ Static Imaging Techniques
▪ Metabolic Imaging
Brain Disorders
• Stroke
• Brain Tumors
• Head Injuries
Intelligence and Neuroscience
• Intelligence and Brain Size
• Intelligence and Neurons
• Intelligence and Brain Metabolism
• Biological Bases of Intelligence Testing
• The P-FIT Theory of Intelligence
Did you know? Our brains are a central processing unit for
everything we do.
Things to remember:
• Cognitive psychologists are especially concerned with
how the anatomy and physiology of the nervous system
affect and are affected by human cognition.
• Cognitive neuroscience: is the field of study linking the
brain and other aspect of the nervous system to
cognitive processing and, ultimately, to behavior.
• The brain is the organ in our bodies that most directly
controls our thoughts, emotions, and motivations; the
brain is reactive as well as directive.
Figure 2.1: The Brain
A major goal of present research of the brain is to study
localization of function.
What is localization of function?
• It refers to the specific areas of the brain that control
specific skills or behaviors.
Cognition in the Brain: The Anatomy and Mechanisms of the
Brain
•
The Nervous
System
•
Is the basis for our ability to perceive,
adapt to, and interact with the world
around us.
Through this system we receive,
process, and then respond to
information from our environment.
Cerebral
cortex
•
Controls many of our thought
processes.
Neurons
•
Basic building block of the nervous
system
Gross Anatomy of the Brain
Three Major
regions of the
Brain
•
•
•
Forebrain
Midbrain
Hindbrain
Note The labels do not correspond exactly to locations of regions
in an adult or even a child’s head. Rather, the terms come from
the physical arrangement of these part of the nervous system of
a developing embryo.
COGNITIVE PSYCHOLOGY CHAPTER 2:Cognitive Neuroscience
Septum
•
Involves in anger and fear.
Amygdala
•
Figure 2.2: Fetal Brain Development
The Forebrain
•
Is the region of the brain located toward the top
and front of the brain.
The forebrain comprises the:
Cerebral
Basal
Limbic
Thalam Hypothal
cortex
Ganglia
System
us
amus
Cerebral cortex
•
•
Is the outer layer of the cerebral hemisphere.
Plays a vital role in our thinking and other mental
processes.
Basal Ganglia
• Collection of neurons crucial to motor function.
Dysfunction: (Lesion to the Basal Ganglia)
Can result to motor deficits.
• Deficits include tremors, involuntary
movements, changes in posture, muscle
tone, and slowness of movement.
Deficits are observed in Parkinson’s disease and
Huntington’s disease.
Limbic System
•
Important to emotion, motivation, memory, and
learning.
• Allows us suppresses instinctive responses.
• So, animals have underdeveloped limbic
systems.
• Helps us to adapt our behaviors flexibly in response
to our changing environment.
The Limbic System comprises three (3) central
interconnected cerebral structures.
Septum
Amygdala
Hippocampus
Plays an important role in emotion as well, especially
in anger and aggression.
• Stimulation in the amygdala commonly
results in fear.
• Also has an enhancing effect for the perception of
emotional stimuli.
Dysfunctions: (Lesion to the amygdala)
• Lesion to the amygdala prevent the enhancing of the
emotional stimuli.
• Damage to or removal of the amygdala can result in
maladaptive lack of fear.
• Organisms approaches potentially
dangerous objects without fear.
• Two other effects of lesions to the amygdala are
visual agnosia (inability to recognize objects) and
hypersexuality (sex addiction)
Additional Information
• Persons with autism display limited activation in the
amygdala.
Hippocampus
From the Greek word for “seahorse” because of its
approximate shape
•
•
Plays an essential role in memory formation.
Is essential for flexible learning and for seeing the
relations among items learned as for spatial memory.
• Appears to keep track of where things are and how
these things are spatially related to each other.
Dysfunctions: (Lesion on the hippocampus)
• Still can recall existing memories but they are unable
to form new memories.
• Korsakoff’s syndrome: A disease that
produces loss of memory function.
Symptoms; apathy, paralysis of muscles
controlling the eye, and tremor.
• Disruption in the hippocampus appears to result in
deficits in declarative memory (memory for pieces of
information) but does not result in deficits in
procedural memory (memory for courses of action)
Renowned case:
• Patient known as H.m.
• After brain surgery retained his memory for events
that transpired before the surgery but had no
memory for events after the surgery.
COGNITIVE PSYCHOLOGY CHAPTER 2:Cognitive Neuroscience
•
Thalamus
•
•
Approximately in the center of the brain
Relays incoming sensory information through groups
of neurons that project to the appropriate region in
the cortex.
• Helps in the control of sleep and walking.
Dysfunctions: (Lesions to the Thalamus)
• When the thalamus malfunctions results can be pain,
tremor, amnesia, impairment of language, and
disruptions in walking and sleeping.
Case:
Schizophrenia
• Reveal abnormal changes in the thalamus (from
imaging and in vivo studies)
• These abnormalities result in difficulties in filtering
stimuli and focusing attention.
• In result, people with schizophrenia
experience symptoms such as
hallucinations and delusions.
–
Hypothalamus
From Greek word “hypo” meaning “under”
•
Located at the base of the forebrain, beneath the
thalamus.
• Regulates behavior related to the species survival:
fighting, feeding, fleeing, and mating.
• Also is active in regulating emotions and reactions to
stress.
• It interacts with the limbic system.
• Plays a role in sleep.
• Important for the functioning of the endocrine
system.
• Involved in the stimulation of the pituitary
glands.
Dysfunction (Lesions to the Hypothalamus)
• Neural loss within the hypothalamus is noted in cases
of narcolepsy (person falls asleep often and at
unpredictable times)
Brainstem
•
•
Helps to control eye movement and coordination.
Connects the forebrain to the spinal cord.
Hypothalamus
A network of neurons essential to the regulation of
consciousness and vital functions such as heartbeat
and breathing.
Hindbrain
• A structure that is in the brain stem.
• Essential for certain kinds of adaptive behaviors.
Injection of small amounts of excitatory amino acids or
electrical stimulation of this area can result:
• An aggressive response
• Confrontational response
• Avoidance or flight response
• Heightened defensive reactivity or reduced
reactivity.
Did you know? Physicians decide of a brain death patient based
on the function of the brainstem.
The Hindbrain
It comprises the
Medulla
The pons
The cerebellum
oblongata
Medulla oblongata
•
•
•
An elongated interior structure located at the point
where the spinal cord enters the skull and joins with
the brain.
Controls heart activity and largely controls breathing,
swallowing and digestion.
The place which nerves from the right side of the
body cross over to the left side of the brain and
nerves from the left side of the body cross over to the
right side of the brain.
The pons
Derives from the Latin for “bridge”
•
•
Reticular activating system (RAS)
•
It comprises the:
Thalamus
Midbrain
Periaqueductal gray (PAG)
The Midbrain
RAS and the thalamus are essential to our having any
conscious awareness of or control over our
existence.
•
Serves as a bridging function.
Serves as a kind of relay station because it contains
neural fibers that pass signals from one part of the
brain to another.
Contains a portion of the RAS and nerves serving
parts of the head and face.
Additional Information:
COGNITIVE PSYCHOLOGY CHAPTER 2:Cognitive Neuroscience
•
•
•
•
Hindbrain; evolutionarily the oldest and most primitive
part of the brain. First part of the brain to develop
prenatally.
Midbrain; relatively newer addition to the brain in
evolutionary terms. Second part of the brain to develop
prenatally.
Forebrain; Most recent evolutionary addition to the
brain. Last part of the three portions of the brain to
develop prenatally.
The evolution of the human brain has offered us the
enhanced ability to exercise voluntary control over
behavior.
Sulci
•
•
Singular, sulcus
Small grooves
Fissures
•
Large grooves
Gyri
•
Bulges between adjacent sulci or fissures.
Gray matter
•
•
Surface of the cerebral cortex that is grayish.
It primarily comprises the grayish neural-cell bodies
that process the information that the brain receives
and sends.
White matter
•
Bran’s interior comprises mostly white, myelinated
axons.
Contralateral transmission
•
From one side to another
Ipsilateral transmission
•
On the same side
The corpus callosum
•
Figure 2.3 Structures of the brain.
Cerebral Cortex and Localization of Function
•
Plays an extremely important role
in human cognition.
• 1–3-millimeter layer that wraps
the surface of the brain.
• Comprises 80% of the human
brain.
• Enables us to think.
Cerebral cortex
• We can plan, Coordinate
thoughts and actions,
perceive visual and sound
patterns, and use
language.
• Forms the outer layer of the two
halves of the brain (left and right
cerebral hemispheres.)
The cerebral cortex comprises three elements:
Sulci
Fissures
Gyri
Is a dense aggregate of neural fibers connecting the
two cerebral hemispheres ( left and right).
If the corpus callosum has been cut:
• The two halves of the brain cannot communicate
with each other.
Humans with epilepsy in whom the corpus callosum has been
severed.
• Surgically severing this neurological bridge prevents
epileptic seizures from spreading from one
hemisphere to another. This procedure drastically
reduces the severity of the seizures.
Hemispheric Specialization
Can be traced back to Marc Dax (1836)
• He treated more than 40 patients suffering from
aphasia (loss of speech) because of brain damage.
• He noticed a relationship between the loss of speech
and the side of the brain in which damage had
occurred,
• He saw every case there had been damage to the left
hemisphere of the brain. He was not able to find even
COGNITIVE PSYCHOLOGY CHAPTER 2:Cognitive Neuroscience
one case of speech loss because of damage to the
right hemisphere only.
French scientist Paul Broca (1861)
• He claimed that an autopsy revealed that an aphasic
stroke present had a lesion in the left cerebral
hemisphere of the brain.
• In 1864, He was convinced that the left hemisphere
of the brain is critical in speech.
• The specific part of the brain that Broca identified is
now called Broca’s area that contributes to speech
German neurologist Carl Wernicke
• He studies language-deficit patients who could speak
but whose speech made no sense.
• He traced language ability to the left hemisphere.
• A different precise location, now known as
Wernicke’s area which contributes to language
comprehension.
Karl Spencer Lashley (1915)
• Often described as the “father of neuropsychology”
• He found that implantations of crudely built
electrodes in apparently identical locations in the
brain yielded different results.
Nobel Prize-winning psychologist Roger Sperry (1964)
• He argued that each hemisphere behaves in many
respects like a separate brain.
• He and his colleagues severed the corpus callosum
connecting the two hemispheres of a cat’s brain.
• They then proved that information presented
visually to one cerebral hemisphere of the cat was
not recognizable to the other hemisphere.
Figure 2.4 Functional Areas of the Cortex
Split-brain patients
•
•
•
People who have undergone operations severing
the corpus callosum
Language is localized in the left hemisphere.
Spatial-orientation tasks seem to be localized in the
right hemisphere.
The left hemisphere
•
Important not only in language but also in
movement.
• To examine past experiences to find patterns.
• Finding patterns is an important step in the
generation of hypothesis.
Disorder:
• Apraxia: Disorders of skilled movements. Often have
had damage to the left hemisphere.
• Such people have lost the ability to carry out
familiar purposeful movements like forming
letters when writing by hand.
The right hemisphere
•
•
•
•
It has little grammatical or phonetic understanding.
It does have very good semantic knowledge (basic
knowledge)
Also involve in practical language use.
Plays a primary role in self-recognition.
COGNITIVE PSYCHOLOGY CHAPTER 2:Cognitive Neuroscience
•
Seems to be responsible for
identification of one’s own face.
the
Dysfunctions:
• People with right-hemisphere damage tend to have
deficits in following conversations or stories.
• Also have difficulties in making inferences from
context and in understanding metaphorical or
humorous speech.
Interesting Research:
• In the studies of split brain, patients presented with a
composite photograph that shows a face that is made
up of the left side and right side of the faces of two
different persons.
• Patients are unaware that they saw conflicting
information in the two halves of the picture.
• When asked to give an answer about what they saw in
words, they report that they saw the image in the right
half of the picture.
• When they are asked to use the fingers of the left hand
(contralaterally sends and receives information to and
from the right hemisphere) to point to what they saw,
participants choose the image from the left half of the
picture.
• It seems that the left hemisphere is controlling the
patients’ verbal processing (speaking) of visual
information. The right hemisphere appears to control
spatial processing (pointing) of visual information.
Figure 2.5 A study with Split-brain patients.
Gazzaniga (1985)
•
Argues that the brain, especially the right
hemisphere, is organized into relatively
independent functioning units that work in parallel.
• He said that operations are often outside of
conscious awareness. These various independent
and often subconscious operations are taking place,
the left hemisphere tries to assign interpretations to
these operations.
• Left hemisphere perceives that the individual is
behaving in a way that does not intrinsically make
any sense.
Example:
Concluding that people are drunk based on their
behaviors or otherwise not in full control of his
senses.
• The brain thus finds a way to assign some meaning
to that behavior.
Levy (1974)
•
•
Has found some evidence that the left hemisphere
tends to process information analytically (piece bypiece, usually in a sequence)
Right hemisphere tends to process it holistically (as
a whole)
The Lobes of the Cerebral Hemispheres
•
Four lobes divide the cerebral hemisphere and cortex
into four parts.
• The four lobes are largely arbitrary anatomical
regions divided by fissures.
• The four lobes, names after the bones of the skull
lying directly over them.
The four lobes:
Frontal
Parietal
Temporal
Occipital
Lobe
Lobe
Lobe
Lobe
The frontal lobe
(toward the front of the brain)
•
•
•
Associated with motor processing and higher
thought process, such as abstract reasoning, problem
solving, planning and judgement.
Tends to be involved when sequences of thoughts or
actions are called for.
Critical in producing speech.
COGNITIVE PSYCHOLOGY CHAPTER 2:Cognitive Neuroscience
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The prefrontal cortex
(toward the front of the frontal lobe)
•
Involved in complex motor control and tasks that
require integration of information over time.
•
Specializes in the planning, control, and execution of
movement, particularly of movement involving any
kind of delayed response.
If your motor cortex were electrically stimulated, you
would react by moving a corresponding body part.
The parietal lobe
(upper back portion of the brain)
•
•
Associated with somatosensory processing.
Receives inputs from the neurons regarding touch,
pain, temperature sense, and limb position when you
are perceiving space and your relationship to it.
The temporal lobe
(directly under your temples)
•
•
•
Associated with auditory processing and
comprehending language.
Also involved in your retention of visual memories.
Matches new things you see to what you have
retained in visual memory.
Figure 2.7 (part 1) Homunculus of the primary motor cortex
Homunculi
(homunculus is Latin for “little person”)
The occipital lobe
•
•
Associated with visual processing.
Contains numerous visual areas, each specialized to
analyze specific aspects of a scene.
Projection areas
•
•
•
•
Are the areas in the lobes in which sensory
processing occurs.
The nerves contain sensory information going to
(projecting to) the thalamus.
It is from here that the sensory information is
communicated to the appropriate area in the
relevant lobe.
Communicate motor information downward through
the spinal cord to the appropriate muscles via the
peripheral nervous system (PNS)
The frontal lobe
(located toward the front of the head, the face)
•
•
Plays a role in judgement, problem solving,
personality, and intentional movement.
It contains the Primary motor cortex.
Primary motor cortex
•
•
It can be mapped by the motor cortex to show where
and in what proportions different parts of the body
are represented in the brain.
Depict the body parts of a person mapped on the
brain.
Primary somatosensory cortex
(located right behind the fontal lobe’s primary motor cortex)
•
•
Receives information from the senses about
pressure, texture, temperature, and pain.
If were electrically stimulated, you probably would
report feeling as if you had been touched.
COGNITIVE PSYCHOLOGY CHAPTER 2:Cognitive Neuroscience
Figure 2.7 (part 2) Homunculus of the Somatosensory Cortex
Cerebral cortex pertaining to hearing.
(located in the temporal lobe, below the parietal lobe)
•
•
•
•
Performs complex auditory analysis.
This analysis is need in understanding human
speech or listening to a symphony.
Specialized- some parts are more sensitive to
sounds of higher pitch, others to sound of lower
pitch.
Primarily contralateral, although both sides of the
auditory area have at least some representations
from each ear.
The visual cortex
(Primarily in the occipital lobe)
•
•
•
Neural fibers carrying visual information travel
ipsilaterally from the left eye to the left cerebral
hemisphere and from the right eye to the right
cerebral hemisphere.
Other fibers cross over the optic chiasma and go
contralaterally to the opposite hemisphere.
Neural fibers go from the left side of the visual field
for each eye to the right side of the visual cortex
Figure 2.8 The optic tract and pathways to the primary visual
cortex.
Indicators of the part of the brain with respect to other body
parts.
Rostral
Refers to the front part of the brain (literally the
“nasal region)
Ventral
Refers to the bottom surface of the body/brain
(the side of the stomach)
Caudal
Literally means tail and refers to the back part
of the body brain)
Dorsal
Refers to the upside of the brain (literally
means “back”, and in animals the back is on the
upside of the body).
Did you know: The brain typically makes up only one fortieth of
the weight of an adult human body. It is also the supreme organ
of cognition.
Neuronal structures and Function
Neurons
•
•
•
Neocortex
•
•
Soma
(cell body)
Transmits electrical signals from one
location to another in the nervous
system.
The greatest concentration of neurons
is in the neocortex of the brain.
Tend to be arranged in the form of
networks, which provide information
and feedback to each other within
various kinds of information
processing.
The part of the brain associated with
complex cognition.
This tissue can contain as many as
100,000 neurons per cubic millimeter.
Four basic parts of neurons
Dendrites
Axon
Soma
Terminal
buttons
COGNITIVE PSYCHOLOGY CHAPTER 2:Cognitive Neuroscience
•
•
Contains the nucleus of the cell(the center portion
that performs metabolic and reproductive functions
for the cell).
Responsible for the life of the neurons and connects
the dendrites to the axon.
Terminal buttons
•
Synapse
Dendrites
•
Branch-like structures that receive information from
other neurons
Did you know? Learning is associated with the formation of new
neuronal connections.
Axon
•
•
•
Long, thin tube that extends (and sometimes splits)
from the soma and responds to the information.
A white, fatty substance that surrounds some of the
axons of the nervous system, which accounts for
some of the whiteness of the white matter of the
brain.
Some are myelinated (in that they are surrounded
by a myelin sheath)
Myelin Sheath
•
Serves as juncture between the terminal buttons of
one or more neurons and the dendrites (sometimes
the soma) of on or more other neurons.
Did you know? Synapses are important in cognition. Rats show
increases in both the size and number of synapses in the brain
because of learning.
Neurotransmitters
Myelin
•
Small knobs found at the ends of the branches of an
axon that do not directly touch the dendrites of the
next neurons. Rather, there is a very small gap, the
synapse.
This sheath, which insulates and protects longer
axons from electrical interference by other neurons
in the area.
•
Chemical messengers for transmission of
information across the synaptic gap to the receiving
dendrites of the next neurons.
Three types of chemical substances are involved in
neurotransmitters
Monoamine
Synthesized by the nervous system
Neurotransmitters through enzymatic actions on one of
the amino acids in our diet.
Amino acid
Obtained directly from the amino acids
Neurotransmitters in our diet without further synthesis.
Neuropeptide
Are peptide chains (molecules made
from the parts of two or more amino
acids)
Acetylcholine
•
•
Associated with memory functions, and the loss of
acetylcholine through Alzheimer’s disease has been
linked to impaired memory functioning in
Alzheimer’s patients.
Plays an important role in sleep arousal.
Dopamine
•
Figure 2.9 The composition of a neuron.
•
Nodes of Ranvier
•
•
Small gaps in the myelin coating along the axon,
which serve to increase conduction speed even
more by helping to create electrical signals.
Also called action potentials.
•
•
•
Associated with attention, learning, and movement
coordination.
Also involved in motivational processes, such as
reward and reinforcement.
Schizophrenics show very high levels of dopamine.
Drugs used to combat schizophrenia often inhibit
dopamine activity.
Patients with Parkinson’s disease show very low
dopamine levels.
COGNITIVE PSYCHOLOGY CHAPTER 2:Cognitive Neuroscience
Did you know? Gambling is a compulsive disorder that results
from impaired impulse control.
studies and in
vivo
(from Latin,
“living”)
•
structure and function of the
human brain.
The recent trend is to focus on
techniques that provide
information about human mental
functioning as it is occurring.
Serotonin
•
•
•
•
Plays an important role in eating behavior and bodyweight regulation.
Also involved in aggression and regulation
impulsivity.
Drugs that block serotonin tend to result in an
increase in aggressive behavior.
High serotonin levels play a role in some types of
anorexia.
• Loss of appetite is related to high serotonin
levels.
Postmortem studies
•
•
•
Note: Lesions: areas where body tissue has been damaged.
Receptors and Drugs
•
•
Receptors
Acute toxicity
•
•
Chronic toxicity
•
Naxolene
(naltrexone)
•
Normally are occupied by the
standard neurotransmitters can be
hijacked by psychopharmacologically
active drugs, legal or illegal.
The molecules of the drugs enter
receptors that normally would be for
neurotransmitter substances
endogenous (originating to) in the
body.
Studying Live Nonhuman Animals
•
To study the changing activity of the living brain,
scientist must use in vivo research. Many early in
vivo techniques were performed exclusively on
animals.
Three ways of doing research to animals.
Obtain single-cell Selective lesioning Employing genetic
recording
knockouts.
Single-cell recording
•
The damage done from a particular
overdose.
Often treated with naxolene or
related drugs.
The damage done by long-term drug
addiction.
Occupies opiate receptors in the
brain better than the opiates
themselves occupy those sites. Thus,
it blocks all effects of narcotics.
• Has such strong affinity for the
endorphin receptors in the brain that
it actually displaces molecules of
narcotics already in these receptors
and then moves into the receptors.
Viewing the structures and functions of the brain
Postmortem
• Techniques on both humans and
(from Latin,
animals. Each technique provides
“after death)
important information about the
Dissection of brains have been done for centuries.
Often use dissection to study the relation between
the brain and behavior.
In the ideal case, studies start during the lifetime of
a person. Researchers observe and document the
behavior of people who show signs of brain damage
while they are alive.
•
•
•
Researchers insert a very thin electrode next to a
single neuron in the brain of an animal.
They then record the changes in electrical activity
that occur in the cell when the animal is exposed to
a stimulus.
In this way, scientists can measure the effects of
certain kinds of stimuli, on the activity of individual
neurons.
The task of the researcher is to find stimuli that
produce a consistent change in the activity of the
neurons.
Selective lesioning
•
•
•
Surgically removing or damaging a part of the brainto observe resulting functional deficits.
Neurochemical ways induce lesions in animals’
brains by administering drugs that destroy only cells
that use a particular neurotransmitter.
Some drugs’ effects are reversible, so that
conductivity in the brain is disrupted only for a
limited amount of time.
COGNITIVE PSYCHOLOGY CHAPTER 2:Cognitive Neuroscience
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Employing genetic knockout procedures
•
•
By using genetic manipulation, animals can be
created that lack certain kinds of cells or receptors
in the brain.
Comparisons with normal animals then indicate
what the function of the missing receptors or cells
may be.
•
•
Studying Live Humans
•
Many of the techniques used to study live animals
cannot be used on human participants.
• An array of less invasive imaging techniques for use
with humans have been developed.
Three types of imaging techniques.
Electrical
Static Imaging
Metabolic Imaging
Recordings
Techniques
Techniques
Techniques
•
Is the record of a small change in the brain’s
electrical activity in response to a stimulating event.
Provide very good information about the timecourse of task-related brain activity.
The ERP technique has been used in a wide variety
of studies.
▪ Studies of mental abilities like selective
attention have investigated individual
differences by using event-related
potentials.
ERP methods are also used to examine language
processing.
Additional Information: N400 effect- is a component of ERPs
that occurs especially when people are presented with
meaningful stimuli.
Static Imaging Techniques
•
Electrical recordings Technique
•
•
The transmission of signals in the brain occurs
through electrical potentials.
When recorded, this activity appears as waves of
various widths (frequencies) and heights
(intensities)
Electroencephalograms (EEGs)
•
Are recordings of the electrical frequencies and
intensities of the living brain, typically recorded over
relatively long periods.
• Possible to study brain-wave activity indicative of
changing mental states such as deep sleep or
dreaming.
• Very sensitive to changes over time.
• Also used as a tool in the diagnosis of epilepsy
because they can indicate whether seizures appear
in both sides of the at the same time, or whether
they originate in one part of the brain and then
spread.
To obtain EEG recording:
• Electrodes are placed at various points along the
surface of the scalp.
• The electrical activity of underlying brain areas is
then recorded.
• Therefore, the information is not localized to
specific cells.
Event-related Potentials (ERP)
Psychologists use still images to reveal the structure
of the brain.
• Allow for the observation of large abnormalities of
the brain, such as damage resulting from strokes or
tumors.
• However, they are limited in their resolution and
cannot provide much information about smaller
lesions and aberrations.
Three types of static imaging techniques.
Angiogram
Computed
Magnetic
tomography (CT)
resonance
scans
imaging scans
(MRI)
Computed tomography (CT or CAT) scans
•
Consists of several X-ray images of the brain taken
from different vantage points that, when combined,
result in a three-dimensional image.
Angiography
•
The aim is not to look at the structures in the brain,
but rather to examine blood flow.
• When the brain is active, it needs energy, which is
transported to the brain in the form of oxygen and
glucose by means of blood.
Procedure:
1. In angiography, a dye is injected into an artery that
leads to the brain, and then an X-ray image is taken.
2. The image shows the circulatory system, and it is
possible to detect strokes, aneurysms, or
arteriosclerosis
COGNITIVE PSYCHOLOGY CHAPTER 2:Cognitive Neuroscience
Additional Information:
• Stokes- disruption of the blood flow often caused by
the blockage of the arteries through a foreign
substance.
• Aneurysms- abnormal ballooning of an artery
• Arteriosclerosis- A hardening of arteries that makes
them inflexible and narrow.
Magnetic resonance imaging (MRI)
•
Reveals high-resolution images of the structure of
the living brain by computing and analyzing
magnetic changes in the energy of the orbits of
nuclear particles in the molecules of the body.
• MRIs allow for much clearer picture of the brain
than CT scans.
• Also facilitates the detection of lesions.
Procedure:
1. A strong magnetic field is passed through the brain
of a patient.
2. A scanner detects various patterns of
electromagnetic changes in the atoms of the brain.
3. Theses molecular changes are analyzed by a
computer to produce a three-dimensional picture of
the brain.
4. The picture includes detailed information about
brain structures.
Two kinds of MRIs
Structural MRI
Functional MRI
▪
Metabolic Imaging
Rely on changes that takes place within the brain because of
increased consumption of glucose and oxygen in active areas
of the brain.
Positron
emission
tomography
(PET)
Subtraction method
•
Provide images of the brain’s size and shape
•
Visualize the parts of the brain that are activated
when a person is engaged in a particular task.
This method uses two different measurement:
▪ Taken while the subject was involved in a
more general or control activity.
▪ Taken when the subject was engaged in the
task of interest.
Positron emission tomography (PET) scan
•
•
•
Structural MRI
•
Four types of Metabolic Imaging
Functional
Magnetoencephalography
(Meg)
magnetic
resonance
imaging (fMRI)
•
Functional MRI
•
•
•
Measure increases in oxygen consumption in active
brain areas during kinds of information processing.
Can assist in the diagnosis of disorders of cognitive
decline like Alzheimer’s by searching for
abnormalities in the brain.
Have been used to show that blood flow increases
to the occipital lobe of the brain during visual
processing.
Used for comparatively studying the brains of
people who score high versus low on intelligence
tests.
Have been used to illustrate the integration of
information from various parts of the cortex.
Used to study regional cerebral blood flow during
several activities involving the reading of single
words.
Not highly precise because they require a minimum
of about half a minute to produce data regarding
glucose consumption.
Functional magnetic resonance imaging (fMRI)
•
•
Figure2.10 Magnetic Resonance Imaging (MRI)
Is aa neuroimaging technique that uses magnetic
fields to construct a detailed representation in three
dimensions of levels of activity in various parts of
the brain at a given moment in time.
Creates a magnetic field that induces changes in the
particles of oxygen atoms.
COGNITIVE PSYCHOLOGY CHAPTER 2:Cognitive Neuroscience
•
Can identify regions of the brain active in many
areas such as vision, attention, language, and
memory.
Two related procedures
Pharmacological MRI
Diffusion tensor imaging
(phMRI)
(DTI)
Pharmacological MRI
•
•
•
Combines fMRI methods with the study of
psychopharmacological agents.
These studies examine the influence and role of
psychopharmacological agents on the brain.
Allowed for the examination of drugs used for
treatments.
Diffusion tensor imaging (DTI)
•
•
Examines the restricted dispersion of water in tissue
and, of special interest, in axons.
Measures how far protons have moved in a
particular direction within a specific time interval.
Recently developed technique:
Transcranial magnetic stimulation (TMS)
•
Temporarily disrupts the normal activity of the brain
in a limited area.
• It can imitate lesions in the brain or stimulate brain
regions.
Procedure:
1. Requires placing a coil in a person’s head and then
allowing an electrical current to pass through it.
2. The current generates a magnetic field.
3. This field disrupts the small area (no more than a
cubic centimeter) beneath it.
4. The researcher can then look at cognitive
functioning when the area is disrupted.
5. This method is restricted to brain regions that lie
close to the surface of the head.
Figure 2.11 Brain Imaging Techniques.
Brain Disorders
•
•
Magnetoencephalography (MEG)
•
•
Measures activity of the brain from outside the
head (similar to EEG) by picking up magnetic fields
emitted by changes in brain activity.
Is used to help surgeons locate pathological
structures in the brain.
A number of brain disorders can impair cognitive
functioning.
Brain disorders can give us valuable insight into the
functioning of the brain.
Stroke
•
•
•
Vascular disorder- is a brain disorder caused by a
stroke.
Strokes occur when the flow of blood to the brain
undergoes a sudden disruption.
People who experience stoke typically show marked
loss of cognitive functioning.
COGNITIVE PSYCHOLOGY CHAPTER 2:Cognitive Neuroscience
▪
The nature of the loss depends on the area
of the brain that is affected by the stroke.
Two kinds of strokes may occur.
Ischemic stroke
Hemorrhagic stroke
Ischemic stroke
•
•
•
Usually occurs when a buildup of fatty tissue occurs
in blood vessels over a period of years.
A piece of this tissue breaks off and gets lodged in
arteries of the brain.
Ischemic strokes can be treated by clot-busting
drugs.
Hemorrhagic stroke
•
•
•
•
•
•
•
•
Occurs when a blood vessel in the brain suddenly
breaks.
The blood spills into surrounding tissue.
As the blood spills over, brain cells in the affected
areas begin to die.
Typical symptoms of strokes.
Numbness or weakness in the face, arms, or legs
(especially on one side of the body)
Confusion, difficulty speaking or understanding
speech.
Vision disturbances in one or both eyes.
Dizziness, trouble walking, loss of balance or
coordination
Severe headache with no known cause
Benign tumors
•
•
•
•
Do not contain cancer cells.
They typically can be removed and will not grow
back.
Cells from benign tumors do not invade surrounding
cells or spread to other parts of the body.
If the tumor press against sensitive areas of the
brain, they can result in serious cognitive
impairments.
Malignant brain tumors
•
•
•
•
•
Contain cancer cells.
More serious and usually threaten the victim’s life.
Often grow quickly.
Tend to invade surrounding healthy brain tissue.
Malignant cells may break away and cause cancer in
other parts of the body
Most common symptoms of brain tumors.
•
•
•
•
•
•
•
•
Headaches (usually worse in the morning)
Nausea or vomiting
Changes in speech, vision, or hearing.
Problems balancing or walking.
Changes in mood, personality, or ability to
concentrate.
Problems with memory
Muscle jerking or twitching (seizure or convulsions)
Numbness or tingling in the arms or legs.
Brain Tumors
•
•
Also called neoplasms.
Can affect cognitive functioning in very serious
ways.
• Tumors can occur in either the gray or the white
matter of the brain.
▪ Tumors of the white matter are more
common.
• Brain tumors can be benign or malignant.
Two types of brain tumors can occur.
Primary brain tumors
Secondary brain tumors
Primary brain tumors
•
•
Start in the brain.
Most childhood brain tumors are of this type.
Secondary brain tumors
•
Start as tumors somewhere else in the body, such as
in the lungs.
Did you know? The diagnosis of brain tumor is typically made
through neurological examination, CT scan, and/or MRI. The
most common form of treatment is a combination of surgery,
radiation, and chemotherapy.
Intelligence and Neuroscience
Karl Lashley
• He studied the brain to find biological indices of
intelligence and other aspects of mental processes.
• Karl Lashley failed, despite great effort.
Some investigators believed:
• At some point we will have clinically useful
psychophysiological indices of intelligence.
• But widely applicable indices will be much longer in
coming.
In the meantime:
• The biological studies we now have are largely
correlational
COGNITIVE PSYCHOLOGY CHAPTER 2:Cognitive Neuroscience
•
•
Intelligence and Brain Size
•
•
•
One line of research looks at the relationship of
brain size or volume to intelligence.
The amount of gray matter in the brain is strongly
correlated with IQ in many areas of the frontal and
temporal lobes.
Brain areas that are correlated with IQ appear to
differ in men vs women.
Intelligence and Neurons
•
•
•
Complex patterns of electrical activity in the brain,
which are prompted by specific stimuli, appear to
correlate with scores on IQ test.
Intelligence was measured by a Multidimensional
Aptitude Battery.
Neural conduction velocity appears to be more
powerful predictor of IQ scores for men than for
women.
▪ So, gender differences may account for
some of the differences in the data.
Intelligence and Brain Metabolism
•
•
•
An alternative approach to studying the brain
suggests that neural efficiency may be related to
intelligence.
Higher intelligence correlates with reduced levels of
glucose metabolism during problem-solving tasks.
▪ That is, smart brains consume less sugar
and therefore expend less effort than less
smart brains doing the same task.
Cerebral efficiency increases as a result of learning
on a relatively complex task involving visuospatial
manipulations.
Biological Bases of Intelligence Testing
•
•
•
Performance on intelligence tests may not indicate
a crucial aspect of intelligence.
People with lesions on the frontal lobe of the brain
frequently perform quite well on standardized IQ
tests.
Intelligence involves the ability to learn from
experience and to adapt to the surrounding
environment.
The P-FIT Theory of Intelligence
•
Stresses the importance of interconnected brain
regions in determining differences in intelligence.
The regions this theory focuses on are the
prefrontal cortex, inferior and superior parietal
lobe, anterior cingulated cortex, and portions of the
temporal and occipital lobes.
Describes patterns of brain activity in people with
different levels of intelligence
COGNITIVE PSYCHOLOGY CHAPTER 2:Cognitive Neuroscience
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