Chapter 2: Cognitive Neuroscience Flashcards
Cognitive Neuroscience
The study of the physiological bases of cognition
Levels of Analysis
Topic can be understood by studying it at a number of different levels of systems
Neurons
Cells in nervous system
- each neuron has a cell body, an axon, and dendrites
The Neuron Doctrine
Individual neurons transmit signals in nervous system, and these cells aren’t continuous
- Ramon y Cajal: used Golgi stain
Nerve Nets
Network of continuously interconnected nerve fibers
Resting Potential
Difference in charge between inside and outside nerve fiber when fiber is at rest
Action Potential
Propogated electrical potential responsible for transmitting neural information and for communication between neurons
Microelectrodes
Small wires that are used to record electrical signals from single neurons
Recording Electrode
Thin glass/ metal probe that can pick up electrical signals fron single neurons
Reference Electrode
Measure difference of charge against recording electrode
Measuring Action Potentials
- Size is not measured
- Rate of firing is measured
Synapse
Space between axon and one neuron and dendrite or cell body of another
Neurotransmitter
Chemical that is released at synapse in response to incoming action potential
- affect electrical signal of receiving neuron, cross synapse and bind with receiving dendrites
Mind
System that creates representations of world, so we can act on it to achieve goals
Principle of Neural Representation
Everything a person experiences is based on representations in the person’s nervous system
Feature Detectors
Neurons that respond best to a specific stimulus (like orientation, size, or more complex features that make up environmental stimuli)
Ex. Hubel and Wiesel cats
Hierarchical Processing
When we perceive different objects we do so in a specific order that moves from lower to higher areas of the brain
Sensory Code
How neural firing represents various characteristics of environment
Specificity Coding
Representation of a stimulus by the firing of specifically tuned neurons specialized to respond only to specific stimulus
*unlikely to be correct
Population Coding
Representation of a stimulus by pattern fo firing of a large number of neurons
Sparse Coding
Representation of a stimulus by a pattern of firing of only a small group of neurons, with the majority of neurons remaining silent
Neuropsychology
Study of behavior of people with brain damage
Cortical Equipotentiality
Brain operates as indivisible whole, as opposed to operating based on specialized areas
Localization of Function
- Specific functions are served by specific areas of brain
- Cognitive functioning declines in specific ways when certain areas of brain are damaged
- Cerebral cortex contains mechanisms responsible for most cognitive functions
Broca’s Aphasia
Labored ungrammatical speech and difficulty in understanding some types of sentences
Wernicke’s Aphasia
Difficulty in understnading language and fluent, grammatically correct, but incoherent speech
Localization of Function: Perception
- Primary recieving areas for the senses
- Coordination of information received from all senses
Double Dissociation
- When damage to on part of brain causes function A to be absent while B is present… and damage to another areas causes function B to be absent while function A is present
- allows us to identify functions that are controlled by different parts of brain
fMRI
Brain imaging technique that measures how blood flow changes in response to cognitive activity
Task-related fMRI
fMRI response that occurs in response to specific cognitive task
Fusiform face area (FFA)
Area in temporal lobe that contains many neurons that respond selectively to faces
Parahippocampal place area (PPA)
Area in temporal lobe that contains neurons that are selectively activated by pictures of indor and outdoor scenes
Extrastriate body area (EBA)
Area in temporal cortex that is activated by pictures of bodies and parts of bodies, but not by faces on other objects
Distributed Representation
Occurs when specific cognition activate many areas of the brain
Central Principle of cognition
Most of our experience is multidimensional
Multidimensional
Multidimentional nature of cognition refers to fact that even simple experiences involve combination of different qualities
Episodic Memories
Events in person’s life
Semantic Memories
Memories for facts
Neural Networks
Interconnected areas of brain that communicate with each other
- Complex structural pathways called networks that form brain’s info highway
- Within structural pathways there are functional pathways that serve different functions
- Network operate dynamically, mirroring dynamic nature of cognition
- Resting state of brain activity, so parts of brain are active all the time, even when there is no cognitive activity
Connectome
Indicate “structural description of network of elements and connections forming the human brain”
Structural Connectivity
The brain’s “wiring diagram” created by axons that connect brain areas
Functional Connectivity
How groups of neurons within the connectome function in relation to types of cognition
- extent to which neural activity in separate brain areas is correlated with each other
6 common functions
- Visual: vision; visual perception
- Somatomotor: 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 environment
- Default Mode: mind wandering, and cognitive activity related to personal life-story, social functions, and monitoring internal emotional states
Dynamics of Cognition
Flow and activity within and across the brain’s functional networks change based on conditions
Default Mode Network
Mode of brain function that occurs when it is at rest
- network of structure that are active when person is not involved in specific tasks
- involved in processes ranging from attention to memory to creativity
