COGP (QUIZ1)

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

was believed to be continuous, like a highway system in which one street connects directly to another, but without stop signs or traffic lights when visualize in this way, this provided a complex pathway you were conducting signals uninterrupted through the network

Ramon y Cajal (1852-1934)

• used to techniques to investigate the nature of the nerve net

• first use the golgi stain, which stained only some of the cells in a slice of brain tissue

• second, he decided to 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

Basic Parts of a Neuron

• cell body

• dendrites

• axon (nerve fiber)

• synapse

• neural circuits

• receptors

Cell Body

is the metabolic center of the neuron; it contains mechanisms to keep the cell alive

Dendrites

branch out from the cell body and receive signals from other neurons

Axon (Nerve Fiber)

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

neurons are not connected indiscriminately to other neurons but form connections only to specific neurons

Receptors

neurons that are specialized to pick up information from the environment, such as the neurons in the eye, ear, and skin

Edgar Adrian

recorded electrical signals from single sensory neurons using microelectrodes in 1920, and was awarded the nobel prize in 1932

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

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

• when the axon, or nerve fiber is at rest, the records, a difference in potential between the tips of two electrodes of 70 millivolts (a millivolt is 1/1000 of a volt)

• stays the same as long as there are no signals in the neuron

• in other words, the inside of the neuron has a charge that is 70 mV more negative than the outside, and this difference continues as long as the neuron is at rest

Action Potential

• as the impulse continues past the electrode, the charge inside the fiber reverses course and start becoming negative again, until it returns to the resting potential

• lasts about 1 millisecond ( 1/1000 of a second)

Neurotransmitters

makes it possible for the signal to be transmitted across the gap that separates the end of the axon from the dendrite or cell body of another neuron

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

which the structure of the brain is changed by experience

Hierarchical Processing

progression from lower to higher areas of the brain

Sensory Coding

refers to how neurons represent various characteristics of the environment

Specificity Coding

an object could be represented by the firing of a specialized neuron that responds only to that subject

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.

Localization of Function

specific function are served by specific areas of the brain

Cerebral Cortex

a layer of tissue about 3 mm thick that covers the brain

Neuropsychology

the study of behavior of people with brain damage

Cortical Equipotentiality

an accepted principle brain function in 1800–the idea that the brain operated as an indivisible whole as opposed to specialized areas

Broca’s area

in 1861, a published work based on patients who had suffered brain damage due to strokes that caused disruption of the blood supply to the brain. These strokes caused damage to an area in the fronal lobe that came to be called:

Broca’s aphasia

patients with this problem–slow, labored, ungrammatical speech caused by damage to broca’s area– are diagnosed having

Carl Wernicke 1879

described a number of patients who had damage to an area in their temporal lobe that came to be called wernicke’s area. His patients produced speech that was fluent and grammatically correct but tended to be incoherent

Occipital Lobe

damage in this where the visual cortex is located resulted in blindness, and that there was a connection between the area of this lobe that was damaged and the place in visual space where the person was blind

Temporal Lobe

the auditory cortex, which receives signals from the ears, is in the upper part of this and is responsible for hearing

Parietal Lobe

the somatosensory cortex, which receives signals from the skin, is in this and is responsible for perceptions of touce, pressure, and pain

Frontal Lobe

reveives signals from all of the senses and is responsible for coordination of senses, as well as higher cognitive functions like thinking and problem solving

Propsopagnosia

• an inability to recognize faces

• people with this dan 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 Disassociation

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. To demonstrate, it is necessary to find two people with brain damage that satisfy the above 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

• this added oxygen increases the magnetic properties of the hemoglobin, so when a magnetic field is presented to the brain, these more highly oxygenated hemoglobin molecules respond more strongly to the magnetic field and cause an increase in this signal

Neural Networks

• are interconnected areas of the brain that can communicate with each other

• the idea of this is a logical extension of the idea of distributed processing, because it makes sense that if many areas are involved in a particular type of cognition, that they might be connected

Structural Connectivity

is the brain’s “wiring diagram” created by nerve axons that connect different brain areas

Visual

vision; visual perception

Somato-motor

movement and touch

Dorsal Attention

attention to visual stimuli and spatial locations

Executive Control

higher-level cognitive tasks involved in working memory and directing attention during tasks

Salience

attending to survival-relevant events in the environment

Default Mode

mind wandering, and cognitive activity related to personal life-story, social functions, and monitoring internal emotional states

The Default Mode Network

network of structures that respond whan a person is not involved in specific tasks