Cognitive Science 1 - Midterm 1 Study Guide

Hebbian Learning

- "Neurons that wire together fire together" - When learning occurs, physical connections are being made in the brain - Hebb's theory was the first testable hypothesis - Eric Kandel proved Hebb's work - Forms a neural network because of the neuron connections that are made while we learn - "When an axon of cell A is near enough to excite a cell B and repeatedly or persistently takes part in firing it, some growth process or metabolic change takes place in one or both cells such that A's efficiency, as one of the cells firing B, is increased." - Hebb, 1949

Analogy

- 4 Stages of Analogical Reasoning: -- COMPREHENSION of the target problem -- REMEMBERING a similar source problem for which the solution is already known -- The source and target are COMPARED AND MAPPED -- The source problem is ADAPTED TO PRODUCE A SOLUTION to the target problem - Analogies are represented in the left prefrontal cortex of the brain

The Default Network

- A network of interacting brain regions known to activate "by default" when a person is not in task -- Aka: when people are not doing anything they will begin mind wandering 3 important things to know about it - Comes upon really fast (fraction of a second) - Thinks outside of the here and now - Cognitive achievement: only species who can do this But is it good? - mind wandering mind is a unhappy mind (emotional cost) - Happiness is in the present moment

The Exemplar approach to categorization

- Accumulation of already encountered instances - If we encounter a new example that resembles something we already encountered, we assign it to that category

Action potentials

- Action potential initiates at the axon hillock; starting at the axon and propagates downwards in one direction from the cell body to the axon terminals -- Axon hillock: where the axon is met ---- Like the calculator of the neuron; collects all the excitatory and inhibitory values ---- Evaluates action potential - Electrical part is only contained within axon -- Chemical part happened at the cell body & at axon terminals;ends of the neuron

Mental Context reinstatement

- Bringing the contexts back to mind with mental imagery - Context-dependent effect: remembering more in the same context, but you can get almost as much information if you remember the context - Studying vocab in two phonetically similar languages (Swahili & Chinyanja), minimize interference by studying them in different contexts -- First: encoded (randomized subjects and let them explore)

The Prototype approach to categorization

- Central member that is average of category and is used to compare (most prototypical member). - Some members of the category are more related to the category than others. - The typical dog, typical summer day, etc.

CRUM

- Computational representational understanding of mind - Thinking can be best understood in terms of representational structures in the mind and computational procedures that operate on those structures (Thagard) -- Thinking is performers by computations operating on representations -- Example: MATHEMATICS ---- Numbers = representational ---- Adding, subtracting, multiplying, dividing = computational - We (our minds) think in concepts (schemas), propositions (declarative knowledge), rules (procedural knowledge), analogies (reasoning, problem solving), images (visual imagery), logic -- Locations/ Represented in the brain: ---- Concepts: basal ganglia, prefrontal cortex ---- Propositions: left hemisphere ---- Rules: basal ganglia, prefrontal cortex ---- Images: occipital lobe

Brain imaging techniques

- Computer Axial Tomography (CAT) - Magnetic resonance imaging (MRI): measures soft tissue structure my aligning protons with a powerful magnet - Positron emission tomography (PET) - functional magnetic resonance imaging (fMRI) a version that shows changes in brain activity over time - transcranial magnetic stimulation (TMS): a noninvasive method to excite neurons in the brain: weak electric currents induced in the tissue by rapidly changing magnetic fields

Harvard's Implicit Association Test

- Conjunction Fallacy: bank teller example. Basically implicit bias. - We tend to put things in certain categories based on what we already know about them.

Phrenology

- Created by Franz Gall - "Science of the mind" - Pseudoscience that is based off of the shape and size of one's skull and equating it to intelligence - Correlated size of eyeballs with the ability to learn; studied brain functions - Localization of function - Essentially thought that brain structure could determine one's personality - 3 basic principles: -- Brain is the sole organ of the mind -- Basic characteristics and intellectual traits are innately determined (nature vs nurture argument) -- Differences in individuals = differences in their brains

Cognitive disorders

- Damage to the dorsal stream: -- Akinetopsia (motion blindness) -- Optic ataxia (deficit in visually guided reaching) - Damage to the ventral stream: -- Achromatopsia (color-blindness) -- Prosopagnosia (face-blindness to familiar faces; affects 2.5% of the world's population)

Neural reinstatement of study context

- Decoding reinstatement of VR contexts (through MRI scans, you can encode which environment the subject is in) - New sample of dual context participants performed same learning protocol, but day 2 testing was in an MRI scanner - When patients mentally reinstate themselves, they shed a facilitation (conquering reinstatement) - Representational similarity analysis - context reinstatement template (high RSA means you're reactivating the original learning contexts well, which means higher recall) - Mental reinstatement of VR contexts improves recall of a foreign language - Cortical reinstatement of context-specific representations - Distinctive environmental contexts may help learners compartmentalize knowledge, reducing interference - Reactivate visual representations

Visual Pathways

- Dorsal (the "where" information, spatial information) - Ventral(the "what" information, information about objects) - Superior collucus (subconscious visual processing; responsible for 10% of visual processing)

PET

- Dynamic/Functional Imaging - Positron Emission Tomography - Requires injection of the radioactive isotope - Measures blood flow in the brain - Bad Temporal resolution (30 second delay) - Good Spatial resolution - Invasive

Localization of Function

- Franz gall - 4 lobes and their function -- frontal lobe: motor activity, planning/decision making -- parietal lobe: sensations - touch, pain, temperature -- temporal lobe: auditory system -- occipital lobe: visual system

fMRI

- Functional magnetic resonance imaging - functional/ dynamic - Shows changes in brain activity over time - Picks up and detects oxygenated blood in the brain - Very strong magnets (measured in teslas) - Bad temporal res., great spatial res. - Non-invasive

Glial cells

- Glial cells are much more abundant than neurons - Albert Einstein's brain had more than the average number of Glial Cells - 3 different types -- Oligodendroglia: provides insulation (myelin) to neurons ---- makes up 76% of glial cells -- Astrocytes: star-shaped cell ---- provides physical and nutritional support for neurons ---- 17% of glial cells are astrocytes ---- "mother cell" ---- help digest parts of dead neurons along with the microglia -- Microglia: digest parts of dead neurons ---- make up 7% of glial cells ---- "janitor cells" (they clean up after the neurons and get rid of unnecessary waste) ---- Diseases such as Parkinson's and Alzheimer's are connected to a microglial cell deficiency

Retrograde Amnesia vs. Anterograde Amnesia

- H.M.'s Hippocampus case study: brain is structures in a from that allows it to be responsible for consolidation & transfer of information from STM to LTM -- Had damage to hippocampus = anterograde amnesia: inability to retain new information subsequent to damage (but able to recall past) -- Retrograde amnesia: can't recall past events

Single-cell/multi-cell recording

- Hubel and Wiesel created single-unit recording and trans-synaptic tracing - Multi-Cell: brain recording -- Measures neuronal activity -- Measures multiple neurons at once -- Invasive - Single: brain recording -- Measures neuronal activity -- Invasive -- Good spatial and temporal resolution

Virtual memory palace

- Imagine yourself in a familiar place or landmark - Method of Loci - discovered that if the visual images of things to be memorized were placed in sequence along imagined journey they are easily recalled later - Order doesn't matter - Higher number = more error - Performance correlated with object placement - Spatial memory is likely a scaffolding - Volitional placement of the objects resulted in improvement in verbal recall - Some subjects in the control group might have used object-location binding strategy to bolster list encoding - VR paradigms provide a unique opportunity to examine the influences of environmental contexts on memory and harness the power of memorable contexts to scaffold with a frame of reference - Conflicts: practicality and affordability - Context could include state of mind as well

Single Context learners

- Learned language in the same virtual world

Dual Context learners

- Learned languages in different virtual worlds - Advantage in interference (high intrusions, less likely to recall word in different language) - Subjects who studied the two languages in two different virtual contexts showed better long-term retention than subjects who studied the languages in the same context

Learning and Memory

- Learning in a nervous system requires a change in the biochemistry of synapse, synaptic plasticity - Sea slug case study: differences in the brain for short and long term memory -- Short term memory- linked to functional changes in existing synapsis/connections -- Long term memory- associated w/ the change in number of synaptic connections

Prototype effect

- Listing: prototypes listed first - Direct rating: prototypes rated higher than others. - Asymmetric reasoning - non-central members are judged as being more similar to central members than the other way around. - Contrastivity

MRI

- Magnetic resonance imaging - structural/static - Uses a strong magnet to measure soft tissue by the alignment of protons - Provides static images - Can be used repeatedly - Bad temporal resolution - Good spatial resolution - Non-invasive

Challenges of VR-based learning platforms

- Memory is context-dependent -- Will knowledge acquired in a virtual environment transfer to real world knowledge? ---- (Protocols in social settings) - Recall -- A changed environment can hurt recall -- Think scuba divers -- Imagining the original study setting can help retrieval of information

Neurogenesis in the Hippocampus

- Neurogenesis: the creation of new neurons - Hippocampus highly effective to cortisol -- Chronic stress leads to decreased neurogenesis - Not all forms of stress is bad: we have high levels of cortisol when we wake up and decreases throughout the day

EEG

- Non-invasive imaging technique that measures electrical activity of neurons and has high temporal resolution - Measures gross electrical activity of the entire brain - Event related potential (ERP) is a response to a representation of a stimulus - Attaches electrodes to the scalp - Invented by Hans Berger - Good temporal res., bad spatial res.

TMS

- Noninvasive - Transcraneal Mangetic Stimulation - Uses magnetic fields to stimulate nerve cells in the brain - Good temporal resolution, bad spatial resoltuion

Cognitive Decline

- Our brain's memory declines around the 3rd decade of our lives - As we age our memory worsens

SOAR

- Rule based cognitive system - Created by Allen Newell - Production memory= rule based learning (if-then) - Knowledge based reasoning - Used to create a system that has the same computational and cognitive abilities as humans

ACT-R

- Rule based cognitive system - Created by John Anderson - Cognitive model that involves the transfer of working memory to production memory and declarative memory

Neural Substrates of LTM

- Semantic memory: linked to the limbic cortex - Hippocampus mediates consolidation of episodic memory - Basal ganglia & motor cortex associated with procedural memory function

Atkinson & Shiffrin's Multistore Model of Memory

- Sensory Memory -- Iconic memory: a brief persistence of a visual impression (think icon/visual) -- Echoic memory: sensory memory that processes auditory information (when auditory stimulus is heard it is stored in memory to be processed and understood) - Working Memory/Short-Term Memory -- Current information monitored and manipulated (working it: can be received by senses or retrieved from LTM) -- Capacity can be increased by chunking (grouping into meaningful wholes) -- Rehearsal also helps with the duration you remember Ex: phone number, social security number - Long Term Memory -- Declarative: explicit recall memory (aware of it) --- Semantic: facts about the world --- Episodic memory: specific personal events --- Procedural: implicit memory (not entirely aware of it) skill based ex: driving

The Feature approach to categorization

- Specify those characteristics of a category that are both necessary and sufficient for membership in that category - Bachelor: adult, human, male, unmarried - Needs to be a precise match - All features must be included for category to be adequate

Roger Sperry's Split Brain patients

- Sperry's experiment found that each hemisphere of the brain (left and right) have their own set of sensations - Performed experiment on monkeys to see the relationship between the left and right hemisphere of the brain - Each hemisphere can operate independently from the other and they both have their own functions - There is one stream of consciousness between the two - Found that what one sees in the opposite line of sight determines how they express it -- Example: Patient who has undergone a lobotomy is shown a ring in his right visual field and a key in his left visual field. He is only able to articulate that he saw a ring because speech is controlled by the left hemisphere and the connections are made contralaterally -- Information is not trapped in the right hemisphere, the patient knows what they saw, they just cannot articulate it. He is able to pick up what he saw using his contralateral hand

Corpus callosotomy

- Split brain experiment - word on right field of view, patient would answer the word on screen because left hemisphere is dominant for verbal processing - word on left field of view, patient would answer nothing because right hemisphere cannot share information with the left, patient is unable to say but can draw it

Stress and its Effects on the Hippocampus

- Stress decrease/shorten dendrite length and inhibit neuronal communications -- When chronic stress it activates HPA axis, this can cause a type of neurotoxins to the neurons

CAT

- Structural/static - Scan is according to the amount of x-ray absorption - Good temporal resolution - Bad spatial resolution - Non-invasive - Computer axial tomography

Categories and Prototypes - Levels

- Superordinate: Overarching category. Fits lots of things. -- Ex: furniture. - Basic level: overall perceived shape, single mental image, general motor program, shortest word, first used by children. -- Ex: chair, desk. - Subordinate: specifics of basic level categories. -- Ex: leather chair, wood chair, L-shaped desk, etc.

The role of presence in retention

- The sense of experiencing a virtual world as a place that one is actually inhibiting, rather than something one is watching on a screen - Forgetting you are in a virtual setting - The dual context results was only significant in those who experienced a high degree of presence in the virtual environments

Specialized cells in Visual Cortex

- V1 (the primary visual area of the cerebral cortex; it is the first stage of the processing of visual inforamtion) -- Processes visual infro from the LGN (lateral geniculate nucleus), which is located in Thalamus in the Visual Cortex; then the processed information is sent to higher visual areas -- P ganglion cells (shape) - layers 3-6 -- M cells (motion) - layers 1, 2 -- Non M - Non P cells, aka kinocellular (color) - all layers -- Simple cells (orientation detectors) -- Complex cells (directionality) - V3 - V5 (extrastriate cortex)

Brain recording and stimulation techniques

- brain's electrical activity measured -- single cell recording -- multiple unit recording ---- Invasive techniques of measuring and recording electrical activity that occurs in a specific part of the brain, or across the brain - brain recording technique -- electroencephalogram (EEG) measures the gross electrical activity of the entire brain ---- Non-invasive, nice medium ---- BUT, there's a lot of noise (interference from the skull, movement, motion artifacts that interfere with signal) -- Event related potential (ERP) is an EEG recording in response to a stimulus

Synaptic transmission

- neurons communicate with each other at synapses - exocytosis: action potential results in the release of neurotransmitters across the synaptic cleft - Neurotransmitters bind to receptors in the dendrite of the receiving neuron creating IPSPs or EPSP which are summed at the axon hillock - Hebbian Learning: neurons that fire together wire together -- eric kandel showed in sea slugs' reflexes using classical conditioning

Retinotopic organization

- two types of visual fields- -- left half of each eyeball is the left visual field; -- right half of each eyeball is the right visual field

Marr's three levels

1.) Computational (infromation-processing systems can be analyzed in terms of the problems they can solve) 2.) Algorithmic (representations and processes by which these systems solve the probelms; the "software") 3.) Implementational (the physical instantiatin of these representations and processes; the "hardware") - Marr's model of vision -- image->primal sketch (based on feature extraction)->2.5D sketch (intermediate stage)->3D sketch (stage we can view images in our mind's eye)