What are the characteristics of Attention?
- Paying attention requires effort
- Attention functions like a spotlight
- Some things automatically attract attention: they "Pop Out"
- There is limited-capacity route to attention
Describe the Dual-Task Paradigm? What do both tasks require?
Task 1: press a button to a probe tone --> use foot pedal to disambiguate from hands OR say "high" or "low" to high or low tone
Task 2: press button 1 if an "X" is in the string of letters, press button 2 if no "X" appears; letters can be clear or fuzzy
Both tasks: require 3 stages of processing: Stimulus recognition, Central attention and response selection, response execution
What is the psychological refractory period (PRP effect)?
- Increased difficulty (fuzzy letters) = stimulus recognition takes longer
- Some processes cannot be shared = 1st stimulus must complete processing before 2nd can access stage processes
- Wait time produces RT2 increase, the PRP effect
What is the attentional blink?
- Task 1: search for and identify designated target among distractors
- Task 2: Indicate if probe letter appeared in the stream
- If T1 is correctly identified --> decrease in performance across next 6/7 items
- If T1 is omitted, there is no performance deficit
Appearance is that of a "blink" in attention
What is important for the attentional blink to occur?
- Information input is critical: blank after T1 disrupts effect, Masking is necessary--limits info on T1 adds additional info to be inhibited
- Distinctiveness/Similarity of targets and distractors: Symbols less effective than digits at disrupting letter processing, in figure: legend indicates type of distractor immediately following T1 and T2
What is the attentional blink influenced by?
- Resource Availability
- Level of Automaticity
- Baseline activation of information
- Motivational Salience
Is memory automatic or controlled processing?
- Automaticity occurs after practice
- Practice may make some stages more efficient, but does not allow parallel processing
Same memory set every trial
Different memory set every trial
Function of Inhibition of Return
- Biases attention to new locations
- If searching, biases search away from previous (unproductive) locations
Inhibition of Return in OCD
- General IOR function observed reduced IOR for LVH stimuli in OCD
- Suggests lateralized deficit in volitional attention
What are the 3 networks in the neural Circuitry for Attentions?
Alerting, Orienting, and Executive network
What is the function of the Alerting Network in attention?
Achieving (maintaining) state of heightened sensitivity to incoming stimuli
What is the function of the Orienting Network in attention?
- Selecting attentional focus
- Moving and engaging the spotlight
What is the function of the executive network in attention?
Maintains and sustains attentional focus
Alerting Network brain areas
- Locus Coeruleus: Norepinephrinergic distribution through cortex, increased arousal
- Frontal Cortex
- Parietal Cortex
Orienting network brain areas: Parietal Lobe
- Responsible for overt and covert attentional selection
- Parietal lobes: Disengagement of attention, Indicate that other stimulus is requesting attention, system is damaged in neglect syndrom, over activation may lead to excess distractibility
Orienting Network: Superior Colliculus
Main function is eye movement control, tracking
Orienting Network: Pulvinar (of the thalamus)
- Selects the new target in the spotlight
- Engages attention
- Anterior Gyrus
- Lateral Prefrontal Cortex
- Maintains, sustains attentional focus
- Damage produces rumination
What are concepts and categories good for?
- Reduces complexity of the environment (chunking)
- Allow rapid, easy identification of objects
- Reduces need for constant new learning
- Evaluate relationships among objects
- Quick response selection
Plato's view of cognition
- Emphasis on true forms
- Mind was a shadow of the external truth
Descartes' view of cognition
- Mind contains ideas
- thoughts, images, sensations
- Ideas are the fundamental unit of consciousness
1.) What is a concept
2.) What does it do
3.) How is it expressed?
- 1.) The fundamental unit of thought for modern philosophers
- 2.) Concepts organize information, similar to categories, define categories
- 3.) Simple concepts can be expressed by language, but the linguistic definition is NOT identical to the concept
- Information can be part of conceptual knowledge but not necessary for definition
- Linguistic definitions are NOT conceptual categories
Children begin concepts using...(Piaget)
- Linguistic definitions
- Hypothesis testing
- Developed by questions/answers with adults
What are the 3 types of concept?
- Single: cards with red; cards with circles
- Conjunctive: cards with red circles or cards with 2 borders and 2 shapes
- Disjunctive: cards with either a read shape or a square of any color
What are 2 strategies to developing concepts?
- Wholist (reception): take first positive instance, note attributes, each subsequent instance eliminate any attribute that doe not recure
- Conservative: Find 1st positive instance, test additional cards varying by one dimension from criterion card
Concept forming with familiar items
- Categories with fuzzy borders
- artificial categories designed as unambiguous
- Natural categories have ambiguous 'sort of' members
What are prototypes?
Summaries of concept
Prototypical objects are more influenced by...
Typically a basic level: level at which people most commonly processes information
Differences among categories/concepts are based on...
- Commonalities among members
- Differences with non-members
- Alignable differences: based on a commonality
- Nonalignable differences: not based on commonality
What are the 3 types of category pairs?
- 2 basic categories, same superordinate: (bed-couch, horse-cow)
- 2 basic categories, different superordinate: (bed-horse, couch-cow)
- 2 superordinate categories (furniture animals)
What are Theory-based categories?
- Tend to organize new information based on previous info
- Generate arbitrary criteria
- Prior knowledge affects category formation (Piaget redux)
What is a lexicon
Dictionary: internal, mental representation, known words
What are two ways to measure lexical access?
- Lexical decision: is stimulus a word (y/n)
- Word naming: say word quickly
What are 3 lexical units?
- Shorter RTs for frequent or familiar words
What is repitition priming?
- Present word
- Repeat item on subsequent trial = shorter RT
What is Semantic Priming?
Present word, activation flows to nearyby nodes, access to activated nodes appears as shorter RTs
What are symbolic network models of knowledge?
Concepts represented by nodes, nodes connected via links
What is the TLC model?
- Teachable-language-comprehended, by R. Quillian
- represented as a hierarchical tree
- Prediction: number of nodes to intersection will be associated with search time
- Problems with TLC: doesn't account for the effect of basic categories or prototypicality and fuzzy borders
What is the Spreading Activation Model?
- Each concept is a node in the network
- Nodes related by links, not hierarchy
- Related nodes close together (central members of categories)
- Unrelated nodes far apart (peripheral members of categories)
TLC vs. SAM
- Subjects reject "school is a bus" or "school is a house" quickly
- In SAM, school and bus close
- In TLC nodes far apart--requires more time to reject
Events are represented by...
- propositions or a relationship among concepts
- Predictions: responses to questions should be quicker within propositions compared with between propositions (concepts + relationships)
What is a schema?
- concept-like info about events and related concepts
- a way of organizing concepts and info into practical, useful sets
- Proposition template
What is a script?
- A concept regarding a typical sequence of actions in common events
- Proposition template
- Derived from schemata, organizes info about an event
- Makes events familiar and comprehensible
Recall is often...
a reconstruction with schema filling in the details
Representation of Knowledge summary
- Info stored in semantic network
- Events represented as propositions
- Categories or groups of events may represented in schemata: scripts detail event sequences with schemata
- Episodic info has modality-specific nodes
- Knowledge can be stored in networks of neurons
- Knowledge must be acquired and accessed: the process of learning and memory
What are amodal systems?
- Modality specific conceptual systems
- Semantic networks: relatedness: semantic assoc., semantic memory
- Propositions: relatedness: contextual organization
What were the conclusions about Modality Specific Conceptual Systems?
- Changing modality increased sentence verification times
- Semantic association alone did not reduce RT
What are modal systems?
- Perceptual neural circuits encode stimulus
- Memory involves top down reactivation of same code (neural patterns)
- Neural circuits-metaphor underlying neural network models
What is the primary component of the neural network?
- Node: units, simulate neurons, receive input from multiple sources, connected for output to multiple target
- Implemented as software
What is the smallest network?
- 2 input nodes
- 1 output node
- no intermediate (hidden layer)
What are activation levels?
the weighted sums of the inputs
What do the clarity of images depend on?
- Familiarity, Memory, and schemas
- Larger objects perceived more quickly
When has learning occurred?
Learning has occurred when there is a relatively long term change in behavior that results from experience
What are similar requirements for learning and memory?
- Both require changing behavior: Learning: process of acquisition, Memory: implies learning
- Each is evidence of the other: Learning implies memory, and memory implies learning
Describe the habituation as a mechanism of learning theory?
Decrease in the strength of the response following repeated presentations
What is dishabituation?
- Unrelated stimulus increases response strength
- Habituate to gunshots @ firing range...attractive range instructor
Describe sensitization as a mechanism in learning theory
- Increase in strength of response following repeated presentations
- Soldiers sensitize to nearby artillery shells
- Sensitization generalizes PTSD
- High intensity: sensitization
- Moderate intensity: habituation-sensitization
Describe the Dual-Process in Habituation/Sensitization
- Both processes evoked
- Example: opponent-process often lead to after effects (visual after images, emotional, etc.)
Name and describe two types of conditioning
- Appetitive: Meat powder conditioning in hungry dogs, US is pleasant, satisfies a need or motivation
- Aversive: Eyeblink conditioning, US is unpleasant, normally avoided, causing discomfort
What are the 4 phases of classical conditioning?
What is the Garcia Effect?
- Pair taste with nausea
- novel food in the environment - nausea
- Lab: novel taste in water with injection of LiCl
- ISI = 2 hours
What is the Coolidge Effect?
Describe the Habituation phase of classical conditioning
- CS may have some US value
- present set of CS-only trials
- Decreases US-UR association
- Latent inhibition
Describe the Acquisition phase of classical conditioning
- CS-US association trial
- Intersperse CS-only test trials to assess development
Describe the Extinction phase of classical conditioning
- Repeated CS-only trials
- Assess stability of newly acquired conditional effect
Describe the reacquisition phase of classical conditioning
- Assess savings
- spontaneous recovery
- phase may delayed (hours, days, weeks)
Describe Delay conditioning
- Most typical procedure
- CS precedes US
- CS and US co-terminate
Describe Trace Conditioning
- CS terminates prior to US representation
- more difficult
- requires hippocampus
Describe the Discrimination phase of classical conditioning
- CS+ predicts US
- CS- does not
- CR appears to CS+, but not to CS-
What are the conditioning attributes of the Introvert?
- Reactive to external stimuli
- Tend to withdraw
- Condition easily
What are the conditioning attributes of an extrovert?
- Less reactive
- Condition less easily
Describe Higher Order conditioning?
- CS2 through association with another CS1 produces CR
- Wasp sting --> fear to sight of wasp
- Tool shed --> wasps
- Tool shed --> fear, anxiety
Describe sensory preconditioning
- Like higher order
- CS2-CS1 association precedes CS1-US association
- Tool sheds (already assoc. with wasps) --> fear, anxiety
What is Thorndike's Law of Effect
- A behavior followed by satisfying consequences will be 'stamped in'
- A behavior followed by an annoyer will be 'stamped out'
Describe Skinner's operant conditioning
- Emitted behaviors operate on the environment
- Reinforcers increase the probability that an emitted behavior will be produced again
- Punishers decrease the probability
- Skinner Box- the standard laboratory equipment of the 50s and early 60s
- Learning results from association of stimuli
- Contiguity produces association
What are the challenges to Guthrie's theory
- Garcia effect no predicted
- Free-US training
What is Rescorla-Wagner's modern learning theory?
- A cognitive approach to learning
- Learn that CS predicts (is informative regarding) US
- Response depends on info content of stimulus
- US does not proved additional (predictive) info regarding US
MacKintosh, Pearce & Hall
- Emphasize attention to CS
- Elements available for association
- Associative strengths determine conditioning
- Learning results from formation of Cell AssembliesCovactivation of 2 neurons-synapse between them is strengthened
- Synapse where change occurs is known as a Hebbian synapse
- Hebbian and Rescoral-Wagner approaches are not necessarily mutually exclusive
Fundamental Principle of Neural Network and Learning
- If 2 neurons (nodes) are active simultaneously
- Then the synapse (weight) should be strengthened
- type of learning
- network learns by contiguity
- but contiguity not necessary for learning
- Outcomes of behavior affect subsequent behavior
- alternative strategies for 'teaching' a network have been devised
- Associative strength between 2 stimuli is a function of the difference between the present strength and the target (expected) strength
- A behavior produces suprising outcome --> rapid change in association
- A behavior produces the expected satisfying outcome --> little change in associations
- Principles implemented in connections networks as the Delta Rule
Delta Rule of Learning
- learning is proportional to unexpected results
- learning does not occur in a single cycle
How does info storage occur in a neural network?
- Storage not in any one, single location
- no one memory trace or engram, each cell contributes to many memories
- memory is a property of how all the nodes are connected with each other
- network operates as in accordance with Lashley's principle of mass action
Δwit = (lr) (ai) (atat),
- Δwit: is the change in the weight connecting nodes at twolayers (e.g., input and output)
- lr: is the learning rate, typically assumed to be thereciprocal of the number of input nodes
- ai: is the activation level of the input unit
- at: is the correct activation level of the target output unit
- (i.e., You know if the two nodes (or neurons) are active or not)
Herman Ebbinghaus and early memory Research
- Used nonsense trigrams in study of memory
- Wanted to study pure memory
- How to exclude influence of prior experience
- Trigrams could be totally novel
- Did not require ‘habituation’ as often used inconditioning procedures
Describe "savings" in terms of early memory research
- Relearning takes fewer presentations than originallearning
- Savings = (trialsoriginal – trialsrelearning)/trialsoriginal
- If perfect savings: (20 – 0)/20 = 1.0
- If no savings: (20 – 20)/20 = 0
- If some savings: (20 – 12)/20 = 8/20 = .4
The Forgetting Curve
- Most forgetting occurs in1st hour after learning
- Rate of loss is not constant0.81
- Counter to beliefs of thetime
- Rate of loss decelerates
- Relearning is alwayseasier than the original
- Something is alwayssaved
Why Does Forgetting Occur?
Define Decay and Interference
- Decay: Associations become weaker --> occurs in perceptual buffers, short-term storage, access links to stored info decay with disuse
- Memory traces fade: Ebbinghaus’ explanation
- Memory strength depends on: Original strength (original learning), Time since learning (savings)
- Interference: Memory cannot be retrieved because --> occurs when new info is placed in perceptual buffers, checking access to long-term storage
What is William James' Model of Memory?
- Primary memory: Knowledge of which we are currently aware
- Secondary memory: Information available for recall, Things we could be aware of
- Although not a direct antecedent, is similar toa number of modern models including AS3S,the modal model
Modal Memory Model
- Three sequential registers (or buffers): Each can store information, Differ on characteristics of capacity, duration, etc.
- Information not transferred to the next store is lost
- Information maintained in STM by Rehearsal
- Executive control areas have access to memory stores
- Response selection, attention, etc.
Describe Sensory registers
- Based on Sperling’s work
- Modality specific
- Iconic – visual
- Echoic - auditory
- Fairly large capacity
- 12 – 20 items ( or more)
- Short Duration:.25 - .5 s for the icon, 2 – 4 s for the echo (??)
- Exhaustive retrieval available(with appropriate cues) )
- Vulnerable to masking and decay
Describe short term memory (STM)
- Based on Miller’s and the Brown &Petersons work
- Contains exact sensory features
- Small capacity: 7 ± 2 items, Items may be ‘chunked’
- Duration of 18 - 30 s
- Exhaustive retrieval available(within time limits)
- Vulnerable to both interference and decay
- New items displace old
What is the Brown/Peterson Task?
- Provided letters for recall: Example: J V G M T
- Asked to count backwards out-loud by 3’s: Begin with different number each trial, Decreases ability to rehearse letters, Time for counting varies: 3, 9, 18, 30 s
- Recall letters
- Results: Poorer recall withgreater interval, Almost no recall at 30 seconds
- What most people refer to as‘memory’
- Stores semantic information: Gist, abstracted material, NOT exact sensory information
- Very large (infinite) capacity
- Very long (infinite) duration
- Partial retrieval: depends on cue, reconstructive
- Retrieval failure due to poor cues, interference, brain injury
What is the serial learning effect?
- List learning: 36 words, Presented 3 s per / word, Recall words
- Serial Position Effect: Position of item in listpredicts likelihood ofsubsequent recall
- Items at end of listremembered better
- Usually the first to be recalled: Immediate awareness, Dumped onto responsesheet ASAP
- Result of STM: If 1 minute delay with fillertask (spoken arithmetic) --> effect reduced
What is the primacy effect?
- Items at the beginning of listhave higher probability of recall
- Usually receive the most rehearsal
- Most likely to beconsolidated
- Result of LTM
- If quick presentation rate (1word / s) to preventrehearsal--> primacy effect reduced
Describe Amneisa effects and the modal model
- Most common amnesia: anterograde – inability toform new long-term memories: STM intact – digit span, word span are normal, Normal on tests of implicit memory/procedural memory, LTM retrieval is normal, Cannot learn new information for long term storage
- Retrograde amnesia is the inability to retrieveprevious LTM information: Never occurs without anterograde amnesia