Cognitive Neuroscience (CH 2) Flashcards
What is Cognitive Neuroscience?
-Study of the physiological basis of cognition
What are Veters?
-The idea that a topic can be studied in a number of different ways w/ each approach contributing to its own dimension & understanding
What are the processes for Perception?
-Chemical Processes–>Neurons activated–> Brain Structures activated–> Groups of Brain Structures activated–>Perception
What are the processes Memory?
-Chemical Processes–>Neuron activated–> Brain Storage–> Storage Activated–> Memory
What are Nerve Nets?
-Interconnected complex pathway for conducting signals uninterrupted through a network
What is Neuron Doctrine?
-The idea that individual cells transmit signals to nervous system & are not continuous
What is the Soma?
- Cell body
- The metabolic center of a neuron=keeps cell alive
What are Dendrites?
-Receive signals from other neurons
What are Axons/Nerve Fibers?
-Long process that transmits signals to other neurons
What are Cajal’s 3 Conclusion about Neurons?
- Synapse= gap between a neuron’s axon & the dendrites of another neuron
- Neural Circuits= Neuron’s forming connection w/ specific neurons
- Receptors= Neuron’s specialized in picking up info from environment
What was Edgar Adrian (1920s) famous for?
- Record electrical signals from Single Sensory Neuron
- Used Microelectrodes (small shaft of hollow glass w/ conductive salt solution)
What did Edgar Adrian discover?
- Used 2 electrodes. 1 inside neuron & the other for reference that located far away
- When axon is at rest, Resting Potential= -70mV
What is a Nerve Impulse?
-Transmitted down axon when receptor is stimulated
What is Action Potential?
- When the charge of inside axon rise to +40mV
- Transmitters are then released when hits the dendrites
- Applying more pressure= increased firing rate
What is the Principle of Neural Representation?
- Everything a person experiences= based on representation in the person’s nervous system
- Neurons at higher levels of the visual system fire to complex stimuli like geometrical patterns & faces
- Specific stimuli causes neural firing that is distributed across many areas of cortex
What are Hubel & Wiesas famous for?
-Presented visual stimuli to cats & determined which stimuli caused specific neurons to fire
What did Hubel & Wiesas discover?
- Each neuron in visual area of the cortex responded to a specific type of stimulation presented to a small area of Retina
- Features Detectors= Responded to orientation, movement, length
What is Experience-Dependent Plasticity?
- Structure of brain is changed by experience
- Rearing kittens in an enviornment w/ only vertical lines= Visual Cortex reshaped so it contained neurons that responded to vertical lines and non responded to horizontal lines
- Supports idea that that perception is determined by neurons that fire to specific qualities of a stimulus
What was Gross famous for?
-Study response of neurons in Temporal Lobe of the monkey’s cortex
What did Gross Discover?
- Neurons in the Temporal Lobe started firing when shadow of hand was being tested
- Other areas of the Temporal Lobe responded to faces
What is Hierarchial Processing in Visual Cortex?
- Simpler stimuli send axons to higher levels of the Visual System
- Then those signal of neurons combine & interact to see geo patterns
- then they send signal to higher areas for response to faces
What is Sensory Coding?
-How neurons represent various characteristics of the enviornment
What is Specificity Coding?
-Object could be represented by firing of a specialized neuron that responds ONLY TO THAT OBJECT
What is the alternate idea of Specificity coding?
-Number of neurons are involved in representing an object
What is Population Coding?
- Representation of a particular object by the pattern of firing large number of neurons
- Large # of stimuli can be represented bc large groups of neurons can create hella different patterns
What is Sparse Coding?
- Particular object is represented by a pattern of a small group of neurons w/ the majority being silent
- Particular neuron can respond to more than 1 stimuli
What is Localization of Function?
- Specific functions are served by specific areas of the brain
- Many functions are served by Cerebral Cortex= layer 3mm= covers brain
- Other functions are served by Subcortical Areas=located below cortex
What is Cortical Equipotemality?
-Belief in 1800s that brain operated as indivisible whole
What is Broca’s area and Broca’s Aphasia?
- Damage in the Frontal Lobe= caused patients to have labored, ungrammatical sentences
- Broca’s Aphasia= patients w/ damaged language production
What is Wernicke’s Area and Wernicke’s Aphasia?
- Damage in Temporal Lobe
- Wernicke’s Aphasia= patients w/ incoherent speech w/ good grammatical structure & were unable to comprehend others
What happens when there’s damage to Occipital Lobe?
- Blindness
- A connection between area of Occipital Lobe that was damaged & place in the visual space where person was blind
- EX= Damage to left part of occipital lobe= area of blindness was in the upper right part of visual space
How does the Auditory Cortex work?
- Receives signals from ears
- Located in Upper Temporal Lobe= ears
How does the Somatosensory Cortex work?
- Receive signals from skin= touch, pain, pressure
- Located in Partietal Lobe
How does the Frontal Lobe work?
- Receives signals from all senses
- Responsible for coordination of the senses, thinking, & problem solving
What is Prosopagnosia?
- Inability to recognize faces
- Caused by damaged to the Temporal Lobe in the lower right side
What is Double Dissociation?
- When damage to one area caused Function A to be present but Function B to absent
- When damage to another area caused function A to be absent but Function B to be present
What is Tsao & coworkers famous for?
-Recording single neurons= determining the localization of function
How did Tsao & Coworkers make their discovery? & what did they Conclude?
- Recording in the lower part of the monkey’s Temporal Lobe when responding to different shapes/ stimuli
- Found that 97% of neurons within the small area of the lower part of the temporal lobe responded to picture of faces & not other objects
- Supported by brain imaging
How does fMRI work?
- Takes advantage that neural activity causes brain to bring in more O2
- This O2 binds to hemoglobin molecules in the blood which increases magnetic properties of hemoglobin= increases fMRI signal
What are Voxels?
-Small units of 2-3mm of analysis created by the fMRI
What is Task Related fMRI?
-Change in brain activity that’s linked specifically to task
What is the Fusiform Face Area? (FFA)
- Face area located at Fusiform Gyrus on the underside of temporal lobe
- This is the same part of the brain that is damaged in prosopagnosia cases
What is the Parahippocampal Place Area & how is it activated?
- Area that is activated when perceiving pictures of outdoor & indoor scenes
- Spatial layout is important bc there’s an increase in activation when viewing empty & fully furnished rooms
What is the Extrastriate Body Area (EBA) & how is it activated?
-Activated by pictures of body parts and bodies
What is the Central Principle of Cognition?
- Most of our experience is Multidimensional
- Different areas respond to different features of humans
What is Distributed Representation?
-Looking at something, thinking/remembering activates hella and sometimes widely separated areas of the brain
What are Episodic Memories?
-Events that happened in your life
What are Semantic Memories?
-Facts
What is the 1st Path in Language Processing?
-Involved w/ processing sounds, productions of speech, & saying words
What is the 2nd Path in Language Processing?
-Understanding sentences
What are Neural Networks?
- Interconnected areas of the brain that communicates with each other
- 4 principles
What are the 4 Principles of Neural Networks?
- Complex structural pathways= information highway
- Within these pathways are functional pathways that serve different functions
- Operate dynamically
- During the Resting state of brain activity, parts of the brain are active all the time even when there’s no cognitive activity
How is the brains “Wiring Diagram” created?
-Nerve axons connecting to different areas of the brain
What is Track Weighted Imaging? (TWI)
- Based on detection on how water diffuses along the length of nerve fibers
- Connectome= structural description of the network of elements & connecting forming the brain
What is Functional Connectivity?
-Different parts of the brain’s neural networks are involved in carrying out different cognitive or motor tasks
How can Functional Connectivity be measured?
- Measuring the extent to which neural activity in 2 brain areas are correlated
- Method is using Resting State fMRI= measuring when not performing cognitive tasks
- Another method is measuring task-related fMRI at seed & test locations & determining the correlation
- 2 areas that are functionally connected DOES NOT MEAN that they directly communicate by neural pathways
What is the Default Mode Network? (DMN)
- Network of structures that respond when a person is not involved in specific tasks= mod of brain function that occurs at rest
- Presentation of a task caused decrease in some areas vs stopping a task caused an increase in the same areas
- Areas in Frontal & Parietal lobes decrease activity during tasks
