Lecture 2 Visual Perception & Sensory Memory, imaging techniques Flashcards
What is dissociation?
A disruption in one component of mental functioning but no impairment of another (e.g. HM)
What is a neuron?
A neuron is a cell that is specialized for receiving and transmitting infromation to other neurons (a neuron impulse) (transmitting info to others neurons)
Structure of a neuron
Dendrites
Axon
Soma
Axon Terminals / Aborizatons (output)
Myelin Sheath
How do neurons talk to eachother?
Through electrical pulses (chemical reactions)
Describe action potential
The change in electrical charge of a neuron from negative to positive results in action potential or spike
This charge propagates from the dendrites and down the axon
All-Or-None-Principle
All action potentials are the same
Either a neuron fires or it does not
Resting Potential
Neuron has not been activated
Synapses
The region in which the axon terminals of one neuron and the dendrites of another come together
May be a few or many synapses
Neurotransmitter
The chemical substance released into the synapse between 2 neurons
Responsible for activating or inhibiting the next post-synaptic neuron
Inhibit occurs because we do not want ALL neurons firing at once
Convergence:
many neurons maConvergence: many neurons may converge onto a single neuron
How do connections between neurons change during learning?
Long-term Potentiation (LTP) :When you’ve activated a network it may be easier to activate the next time
Consolidation:Long-term change over days, weeks, months, or years
What does left hemisphere specialize in?
Language sounds, letters, words, speech, reading, writing, arithmetic, verbal memory, complex voluntary movement
What does right hemisphere specialize in?
Non-language sounds, geometric patterns, faces, nonverbal memory, prosody, narrative, inference, spatial processes, movements in spatial patterns
Masking
reduction or elimination of the visibility of one brief (≤ 50 ms) stimulus, called the “target”, by the presentation of a second brief stimulus, called the “mask”.
Information in sensory memory can be erased
Monocular:
target and mask to one eye
Binocular:
target and mask to both eyes
Dichoptic
target to one eye, mask to other eye
Energy Masking
Occurs with mono and binocular, not with dichoptic
Pattern Masking
Is effective with all, even dichoptic
You will get that masking
Why is there Masking in SM?
Erases information to allow for next event to be cleanly encoded into SM
SM encoding takes how long?
50ms
How long does SM last?
250-500ms (1/4 s) max
SM can select items from display based on what primitive features?
Location
Colour
Angles
What types of masking are there?
Forward
Backward
Energy
Pattern
What is an energy mask?
Such as a flash of light (from someone’s camera), or white noise. Theres no features to it
Pattern Mask
Has features
e.g. circle around the letter was a circle feature
When is masking the strongest?
masking is strongest with energy masking when it happens at same time as stimulus
What is whole-report technique vs partial-report technique?
Whole: Report all items in the display (list all letters)
Partial:Report cued items only (report one row paired with sounds)
Saccades
Movement of the eyes from one fixation to another
25ms - 175 ms
Fixations
Eyes pause to foveate and gather visual information
