Chapter 2 Flashcards
Cognitive Neuroscience
The marriage of neuroscience and cognitive psychology.
Nerve Net Theory
19th Century anatomist’s belief that the brain was made up of a continuous complex pathway of uninterrupted conducting signals. Nerve Net
Camillo Golgi
Staining procedure used to identify single neurons from other tissue.
Myelin Sheath
Myelin is a fatty white substance that surrounds the axon of some nerve cells, forming an electrically insulating layer.
Nodes of Ranvier
Gaps between the Myelin that allow ions in to trigger and speed up action potential
Dendrites receive two types of chemical signals from the presynaptic neuron:
Excitatory: Increases chance neuron will fire
Inhibitory: decreases chance neuron will fire
Localization of Function in the Brain
The idea that specific cognitive functions are served by neurons in specific areas of the brain.
Name the four lobes of the brain
Frontal Lobe
Parietal Lobe
Temporal Lobe
Occipital Lobe
Frontal Lobe
- Front, forehead area
- Broca’s area
- Movement, motor planning,
judgment & reasoning
Parietal Lobe
Located behind frontal lobe and on top of temporal lobe.
- Input for touch, temperature & pain
Temporal Lobe
- Wernicke’s area
- Object recognition
- Includes primary auditory cortex
- By temples
Occipital Lobe
- Located in the back of the head Visual centers Color perception Motion Spatial organization
Define Fusiform face area (FFA) and where it is located.
Thought to respond specifically to faces
Temporal lobe
Prosopagnosia
inability to recognize faces
Parahippocampal place area (PPA)
Helps you identify where things are - “place”
Extrastriate body area (EBA)
Helps you identify body parts - “body”
Broca’s area
Language production
Broca’s Aphasia
Inability to speak
Wernicke’s area
Language comprehension
Wernicke’s Aphasia
Inability to understand language
Agnosia vs Aphasia
language impairment vs visual impairment
Double Dissociation
When two related mental processes are shown to function independently of each other
Example: Broca’s Aphasia (deficit in production) and Wernicke’s Aphasia (deficit in comprehension)
Electro-Encephalography (EEG)
Measures electrical activity Lowest $ Accurate temporal resolution “Noisy” data Lower spatial resolution
Event-Related Potential (ERP)
An ERP is an average of many trials of stimulus presentation. Used with EEG’s.
ERP Components:
Polarity = -/+ Direction
Latency = Time
Positron Emission Tomography (PET)
Measures changes in blood flow
good spatial resolution
Very $ radioisotopes needed ($1,000-$1,200 cost per scan!)
Low accessibility
functional Magnetic Resonance Imaging (fMRI)
Measures changes in blood flow. Excellent spatial resolution. (over a large area) Okay temporal resolution. No radioisotopes! Subject must remain STILL Expensive Low accessibility
Subtraction technique during fMRI
measures brain activity before and during stimulation presentation
Hubel & Wiesel
Feature Detectors
Hubel & Wiesel Neural Code
Pattern of neural firing when the object is present is the representation of the object
Specificity Coding
The representation of a specific stimulus by the firing of specialized neurons that fire only to those specific stimuli. ( Jennifer Aniston neuron)
Distributed Processing / Coding
Activation of a number of different brain areas
Specificity coding
Representation of a specific stimulus by firing of specifically tuned neurons specialized to just respond to a specific stimulus.
Sparse coding: small number of neurons
Population coding: large number of neurons
