Lecture #2 Flashcards
cognitive neuroscience
the study of the physiological
basis of cognition.
Levels of analysis
refers to the idea that a topic can be studied in a number of different
ways, with each approach contributing its own dimension to our understanding
neurons
create and transmit information about what we experience and know
nerve net
a mesh-like structure of nerve cells that are connected to each other.
Camillo Golgi (1843–1926)
Italian anatomist who developed a staining technique in which a thin slice of brain tissue was immersed in a
solution of silver nitrate.
Ramon y Cajal (1852–1934)
Spanish physiologist who used two
techniques to investigate the nature of the nerve net.
2 techniques to investigate the nature of the nerve net
Golgi stain, which
stained only some of the cells in a slice of brain tissue.
study tissue from the brains of newborn animals, because the density of cells in the newborn brain is
small compared with the density in the adult brain.
neuron doctrine
the idea that individual cells transmit signals in the nervous system, and that these cells are not continuous with other cells as proposed by
nerve net theory.
cell body
the metabolic center of
the neuron; it contains mechanisms to keep the cell alive.
dendrites
that branch out from the cell body is to receive signals from other neurons
Axons
(also called nerve fibers) are usually long processes that transmit signals to other neurons.
synapse
a small gap between the end of a neuron’s axon and the dendrites or cell body of another neuron
neural circuits
a network of neurons that are connected by synapses and work together to process and send information in the brain
receptors
are similar to brain neurons in that they have an axon, but they have specialized receptors that pick up information from the environment.
microelectrodes
small shafts of hollow glass filled with a conductive salt solution that can pick up electrical signals at the electrode tip and conduct these signals back to a recording device
2 types of electrode
-recording electrode
-reference electrode
recording electrode
shown with its recording tip inside the neuron
reference electrode
located some distance away so it is not affected by the electrical signals
resting potential
stays the same as long as there are no signals in the neuron
nerve impulse
an electrical signal that travels along a nerve fiber in response to a stimulus and serves to transmit a record of sensation from a receptor or an instruction to act to an effector
action potential
a rapid sequence of changes in the voltage across a membrane, lasts about 1 millisecond
neurotransmitter
chemical messengers that your body can’t function without. Their job is to carry chemical signals (“messages”) from one neuron (nerve cell) to the next target cell. The next target cell can be another nerve cell, a muscle cell or a gland.
principle of neural representation
states that everything a person experiences is based on representations in the person’s nervous system
feature detectors
responded to specific stimulus
features such as orientation, movement, and length.
experience-dependent plasticity
the structure of the brain is changed by experience.
visual cortex
the part of the brain that processes visual information from the eyes. It’s located in the occipital lobe at the back of the brain.
temporal lobe
part of the brain that processes sensory information, stores memories, and helps with language and emotions. It’s located in the forebrain, behind the ears, and near the temples.
hierarchical processing
the idea that information is processed in a hierarchical manner, with higher levels of processing controlling lower levels. This process allows the brain to detect increasingly complex patterns in stimul
problem of sensory coding
the challenge of determining how neural activity carries information about stimuli from the external world. It’s a central issue in sensory physiology.
sensory code
refers to how neurons represent various characteristics of
the environment.
specificity coding
the idea that memory retrieval is improved when the encoding context is the same as the retrieval context
Population coding
the representation of a particular object by the pattern of firing
of a large number of neurons
Sparse coding
occurs when a particular object is represented by a pattern of firing of
only a small group of neurons, with the majority of neurons remaining silent.
Three types of coding:
(a) Specificity coding
(b) Population coding
(c) Sparse coding
localization of function
the idea that specific parts of the brain control specific functions
cerebral cortex
which is a layer of tissue about 3 mm thick that covers the brain; The cortex is the wrinkled covering you see when you look at an intact brain
subcortical areas
the regions of the brain that are located below the cerebral cortex.
neuropsychology
the study of the behavior of people with brain damage.
cortical equipotentiality
the idea that the brain operated as an indivisible whole as opposed to specialized areas
Broca’s area
a region in the brain that controls speech production and articulation
Tan
what Broca’s patients were called as
Broca’s aphasia
Frontal lobe damaged- a language disorder that makes it difficult for people to speak fluently
Wernicke’s area
a region in the brain that is responsible for understanding written and spoken language
Wernicke’s aphasia
Temporal lobe damaged- a type of aphasia that makes it difficult for people to understand spoken and written language
occipital lobe
the part of the brain that processes visual information.
parietal lobe
is a region of the brain that processes sensory information, including touch, pain, and temperature. It’s located at the top rear of the head, between the frontal and occipital lobes.
frontal lobe
receives signals from all of the senses and is responsible for coordination
of the senses, as well as higher cognitive functions like thinking and problem solving.
prosopagnosia
an inability to recognize faces. People with prosopagnosia can tell that a face is a face, but they can’t recognize whose face it is, even for people they know well such as friends and family members.
double dissociation
echnique that compares the effects of brain lesions on different mental functions. It’s used to determine which areas of the brain are responsible for specific mental functions
brain imaging
a noninvasive procedure that uses energy to create images of the brain. The images can show the structure and function of the brain, and are used to diagnose conditions
Functional magnetic resonance imaging (fMRI)
takes advantage of the fact that neural
activity causes the brain to bring in more oxygen, which binds to hemoglobin molecules in the blood
task-related fMRI
the change in brain activity that can be linked specifically to the task. The results of these calculations for each voxel are then displayed as colorful
activation patterns
fusiform face area (FFA)
a part of the human brain that is especially responsive to faces.
parahippocampal place area (PPA)
a region of the brain that processes visual information about scenes and places.
extrastriate body area (EBA)
a part of the brain that helps people see and understand human bodies and body parts.
multidimensional
that different areas respond to different features of humans—illustrates a central principle of cognition: most of our experience
distributed representation
It’s the fact that looking at a face activates many areas
of the brain
Episodic memories
are memories for events in a person’s life, like remembering what you did yesterday
Semantic memories
are memories for facts, like knowing that the capital of California is Sacramento
Neural networks
are interconnected areas of the brain that can communicate with each
other
Structural connectivity
the brain’s “wiring diagram” created by nerve axons that connect
different brain areas
track-weighted imaging
(TWI)
based on detection of how water diffuses along the length
of nerve fibers, shows nerve tracts determined by this
technique
connectome
Pictures of the brain’s pathways obtained by these new techniques to indicate the “structural description of the network of elements and connections forming the human brain” or more simply, the “wiring diagram” of neurons in the brain
functional connectivity
a measure of how different regions of the brain are statistically dependent on each other. It’s a way to study how brain regions interact and exchange information.
resting-state fMRI
a type of brain imaging that measures spontaneous brain activity without requiring a task or stimulus. It’s used to study how brain regions interact with each other when a person is resting or not actively engaged in a task
resting-state functional
connectivity
- Bharat Biswal and coworkers (1995)
-a technique that measures how brain activity correlates when a person is at rest.
seed location
the location of a region of interest (ROI) that is used to identify patterns of connectivity in the brain.
time-series response
indicates how the response changes over time.
test location
response of the test location Somatosensory, which is located in an
area of the brain responsible for sensing touch
Six Common Functional Networks Determined by Resting-State fMRI:
Visual
Somato-motor
Dorsal Attention
Executive Control
Salience
Default mode
Visual network - Function
Vision; visual perception
Somato-motor network- Function
Movement and touch
Dorsal Attention- Function
Attention to visual stimuli and spatial locations
Executive Control- function
Higher-level cognitive tasks involved in working memory and directing attention during tasks
Salience- function
Attending to survival-relevant events in the environment
Default mode -function
Mind wandering, and cognitive activity related to personal life-story,
social functions, and monitoring internal emotional states
