Chapter 2 - Cognitive Neuroscience Flashcards
cognitive neuroscience
the study of the physiological basis of cognition
levels of analysis
the idea that a topic can be studied in many different ways. For example, this book on cognitive psychology explains the behavioral and physiological experiments.
neurons
small units of the brain that create and transmit information about what we experience and know.
nerve net
a complex pathway for conducting signals uninterrupted through the network.
neuron doctrine
the idea that individual cells transmit signals in the nervous system, and that these cells are not continuous with other cells. Discovered by Spanish physiologist Ramon y Cajal.
cell body
the metabolic center of the neuron
dendrites
branch out from the cell body and receive signals from other neurons.
axons
long processes that transmit signals to other neurons
synapse
the gap between the end of a neuron’s axon and the dendrite or cell body of another neuron.
neural circuits
a group of interconnected neurons
receptors
specialized neural structures that respond to environmental stimuli such as light, mechanical stimulation, or chemical.
microelectrodes
small wires that are used to record electrical signals from single neurons.
recording electrode
when used to study neural functioning, a very thin glass or metal probe that can pick up electrical signals from single neurons.
reference electrode
used with a recording electrode to measure the difference between the two. Reference electrodes are placed where the electrical current remains constant so that any changes can be recorded.
resting potential
the difference in charge between the inside and outside of a nerve fiber when the fiber is at rest (no other electrical signals are present).
nerve impulse
an electrical response that is propagated down the length of an axon; also called an action potential.
action potential
propagated electrical potential responsible for transmitting neural information and for communication between neurons. Action potentials travel down a neuron’s axon.
neurotransmitter
a chemical released at the synapse in response to incoming action potentials.
principle of neural representation
states that everything a person experiences is based not on a direct contact with stimuli but representations in the person’s nervous system.
retina
the layer of neurons that lines the back of the eye.
visual cortex
the area at the back of the brain that receives signals from the eye.
feature detector
neurons that respond to specific stimulus features such as orientation, movement, and length.
Discovered in the 1960s by David Hubel and Thorsten Wiesel.
hierarchical processing
processing that occurs in a progression from lower to higher areas of the brain.
sensory code
refers to how neurons represent various characteristics of the environment.
specificity coding
the idea that an object could be represented by the firing of a specialized neuron that responds only to that object.
population coding
the representation of an object by the pattern of firing of a large number of neurons.
sparse coding
when a particular object is represented by a pattern of firing of only a small group of neurons, with the majority of neurons silent.
localization of function
one of the basic principles of brain organization that states specific functions are served by specific areas of the brain.
cerebral cortex
a layer of tissue about 3mm thick that covers the brain.
neuropsychology
the study of the behavior of people with brain damage
Broca’s area
an area of the left frontal lobe that is specialized for speech/language production.
Proposed by Paul Broca in 1861.
Wernicke’s area
an area of the temporal lobe responsible for language comprehension.
occipital lobe
the lobe at the back of the brain that is devoted primarily to analyzing incoming visual information.
temporal lobe
lobe on the side of the brain responsible for language, memory, hearing, and vision.
parietal lobe
lobe at the top of the brain responsible for sensations caused by stimulation of the skin and also some aspects of visual information.
frontal lobe
lobe at the front of the brain that serves higher functions such as language, thought, memory, and motor functioning.
prosopagnosia
a condition caused by damage to the temporal lobe that is characterized by an inability to recognize faces.
double dissociation
occurs if damage to one area of the brain causes function A to be absent while function B is present, and damage to another area causes function B to be absent while function A is present.
magnetic resonance imaging (MRI)
creates images of structures in the brain. A standard technique for detecting tumors and other brain abnormalities.
functional magnetic resonance imaging (fMRI)
a brain imaging technique that measures how blood flow changes in response to cognitive activity.
brain imaging
makes it possible to determine which areas of the brain are active during cognitive processes.
voxels
small cube-shaped areas of the brain about 2 or 3 mm on a side. Voxels are not brain structures but are small units of analysis created by the fMRI.
fusiform face area (FFA)
an area in the temporal lobe that contains many neurons that respond selectively to faces. The same part of the brain that is damaged in cases of prosopagnosia.
parahippocampal place area (PPA)
An area in the temporal lobe that contains neurons that are selectively activated by pictures of indoor and outdoor scenes.
extrastriate body area (EBA)
an area in the temporal cortex that is activated by pictures of bodies and parts of bodies, but not faces or other objects.
distributed representation
the idea that specific cognitive functions activate many areas of the brain.
neural network
groups of neurons or structures that are connected together.
diffusion tensor imaging (DTI)
a technique based on detection of how water diffuses along the length of nerve fibers, for tracing nerve pathways and determining connections
Camillo Golgi
developed a staining technique in which a thin slice of brain tissue was immersed in a solution of silver nitrate; fewer than 1 % of the cells were stained.
Ramon y Cajal
a Spanish physiologist who used two techniques, the Golgi stain and a newborn animal brain. A newborn brain is less dense, and the Golgi stain only affects less than 1% of the tissue; these characteristics made it possible for Cajal to discover that the nerve net is not continuous.
Edgar Adrian
in the 1920s, he was able to record electrical signals from single sensory neurons; awarded the Nobel Prize in 1932. He discovered that each action potential travels all the way down the axon without changing its height or shape.
David Hubel
alongside Thorsten Wiesel found that each neuron in the visual area of the cortex responded to a specific type of stimulation presented to a small area of the retina.
Charles Gross
discovered that the neurons in the temporal lobe responded to complex stimuli and neurons in another area of the temporal lobe responded to faces
Paul Broca
proposed, in 1861, that an area of the left frontal lobe is specialized for speech/language production. This area is now called Broca’s area.
Carl Wernicke
identified, in 1879, an area of the temporal lobe responsible for language comprehension. This area is now called Wernick’s area.
Doris Tsao and coworkers
found that 97% of the neurons within a small area in the lower part of a monkey’s temporal lobe responded to pictures of faces but not to pictures of other types of objects.
Alex Huth and coworkers
were able to determine what kinds of stimuli each voxel responds to using a fMRI and having subjects view film clips of various objects and actions.
