Unit Two. Cognition (How do we know?)
2.1. Perception: We encounter the world around us through sensation—the five senses. Perception takes place when relevant structures within the brain analyze the sensory information it receives and interprets it, gives or remembers the names of the things we encounter through our senses and decides if they represent something we want to approach or avoid.
a. Influences on Perception:
Our senses pick up information on a pretty regular basis that makes no impression on us at all. Indeed, if we were able to become aware of every flicker of light, every sound, and smell, we would have difficulty functioning. Perception involves ignoring (unintentionally or not), a lot of what is going on around us. We do, however, tend to perceive things when we are paying attention, and some things will grab our attention even when our minds are elsewhere—the sound of a rattlesnake shaking its tail in warning will almost certainly get our attention.
Selective attention: You are in a room filled with the noise of conversations. You want to hear the conversation you are having, so you block out all of the other noise and focus on the voice of your conversation partner. In the same situation, you overhear your name mentioned across the room. Someone is talking about you. Your attention is immediately focused.
Perceptual Set: Predisposition to see things one way and not another.
Schemas: concepts that organize information in our experience and creates our perceptual sets.
Top-down processing: A later stimulus determines how we perceive an earlier one. You feel a slap on the back of your head. You turn around ready to fight, or at least yell at the jerk who hit you and you realize it is a close friend who surely means you no harm. The second event causes us to reinterpret the first.
Depth Perception:
Monocular Clues:
Binocular Clues—retinal disparity
Perceptual constancy. We don’t expect things getting closer to us to actually increase in size.
McGurk Effect (What happens when visual cues override other cues?)
b. Perceptual Organization and Interpretation
Cultural background can influence what we perceive as in the Muller-Lyer Illusion.
40 Studies, Reading 5
2.2. Thinking, Problem-Solving
a. Concepts and Creativity
b. Solving Problems and Making Decisions:
Algorithm: Unless you make a mistake, an algorithm will find the right answer (assuming there is a right answer). Mathematical formulas are a kind of algorithm. If you use the right data with the right algorithm, you will get the right answer (such as when you try to find the length of the hypotenuse of a triangle.
Heuristics: a quick way to solve a problem, occasionally prone to errors: trial and error, rules of thumb. It is what you do when faced with a complex problem and incomplete information. One example of an ineffective heuristic is, when taking a multiple choice exam, to select “c” every time.
Mental Set: when faced with a problem that is similar to one already faced, try solving it the same way. This can prove problematic, especially in giving advice.
Fixation: Inability to consider a problem in a new way or with a different perspective
Intuition: Sensing a problem or a solution while lacking real evidence.
Insight—an “aha” moment when a solution is suddenly made clear. Your unconscious mind may have been working on the problem below your level of awareness.
Inductive Reasoning: from the general to the specific.
Deductive Reasoning: from the specific to a generalization. Logic is based on deduction.
Creativity: having the ability to create ideas or solve problems in new ways.
Threshold Theory: A certain level of intelligence is necessary for creativity, although intelligence by itself is not enough.
Convergent Thinking: narrow the field of potential solutions to a problem until we arrive at the best one. Multiple Choice Questions test convergent thinking, as does the MCQ portion of the AP Exam.
Divergent Thinking: Expanding the number of solutions
2.3. Introduction to Memory
40 Studies, Reading 15 (Cognitive Maps)
2.4. Encoding Memories: The process of sensing, processing and storing information to be retrieved later as memories.
Visual Encoding (the most shallow type or processing)
Acoustic Encoding (remembering a sound or a tune.
Semantic encoding (based on meaning—the deepest form of encoding and the most likely to be remembered)
Encoding can be enhanced by
Maintenance Rehearsal: keep repeating the data to be memorized
Elaborative Rehearsal: focus on the meaning of the term and make connections. For example, if you were trying to remember a vocabulary word like “sympathy” you might recall that “sym” as a prefix means “with” and “pathos” means “to suffer.” Therefore, when we have sympathy for someone we are sharing their pain—suffering with them. Can you link this information to the function of the Sympathetic Nervous System?
Self-Reference effect: Apply the term to your own experiences. This is the most effective tool for encoding into Long Term Memory.
Imagery: creating visual images of the idea to be remembered.
2.5. Storing Memories:
If you have ever lost a computer file on the hard drive (or looked for a library book that had been shelved in the wrong place), you understand the importance of mental filing systems. Information in our brains are not dropped in at random, but are filed in ways that make it possible for us to retrieve them (or not).
The Atkinson-Shiffrin three-stage model explains how sensory input is transformed either into long-term memories or is forgotten.
Input: Sensory information
Sensory memory: passing sensory input. It will either pass into the short term memory or bypass the memory without ever having registered. Most sensory information never makes it past this point.
Iconic Memory: very brief sensory memory of a visual stimuli
Echoic Memory: three or four second memory of an auditory stimuli.
Short term memory: Holds seven bits of memory data (plus or minus two) for about thirty seconds (unless you intentionally try to retain it). Short-term memory is aided by chunking, rehearsal, or the use of mnemonic devices.
Encoding into long-term memory (or memory consolidation). If we rehearse or recall information repeatedly we will be reinforcing the neural network that makes long term memory possible. Long-term memory is effectively limitless though memories do fade over time unless they are retrieved regularly. Memories can also be modified and corrupted while moving into long-term memory.
2.6. Retrieving Memories:
Recall—bringing data from long-term memory into conscious awareness. The names of your sixth grade teachers:
Recognition—You see again something you learned previously, although you might not be able to bring it to mind unaided.
Relearning: When we re-learn something we had previously learned and forgotten, we can recapture our lost learning much more quickly than we learned it the first time.
Retrieval Cues
Serial Position Effect: We tend to remember the first and last members of a series.
Recency Effect: We remember the last thing that we saw or was said.
Primacy Effect: We also remember the first thing we saw or heard.
Mnemonic Devices
Method of Loci—building a memory palace for things that need to be remembered
Semantic Network Theory
Priming: activation of memory by association.
Context Dependent Memory: We tend to remember information in the same place we encoded it. We do better taking a test in the same room we learned the information being tested.
State Dependent Memory: Memory is dependent on the state we are in when the memory was encoded: drunk, angry, etc.
Mood-congruent memories: We store our emotions at the same time we store memories and tend to recall them when we are experiencing a congruent mood. When we are angry, we tend to remember other things that made us angry.
Recovered or constructed memories. The theory of recovered memories holds that traumatic memories can be repressed for years but recovered with the help of therapy. Elizabeth Loftus challenges this theory—recovered memories have been created, often by the therapist.
Spacing Effect: We learn better over time than by cramming it all in at once.
Testing Effect: Having retrieved information (as in a test), we can recall it more effectively than if we simply re-read it. This is the theory behind the use of index cards and note taking (and editing).
2.7. Forgetting and Other Memory Challenges
40 Studies, Reading 16 (Implanted and False Memories)
Hermann Ebbinghaus and the Ebbinghhaus Curve: We forget much of what we learned in the first twenty minutes after learning. If we can hold onto a memory for a day, we can probably recall it a month later.
Retroactive Interference: Old information is harder to recall when we learn new information. Once you change a password, you will likely forget the old password quickly.
Proactive Interference: Existing memories block new memory formation.
Amnesia: Retrograde, Anterograde
Source Amnesia (misattribution error)
Deja Vu
Misinformation Effect
Freudian Theory of forgetting: Repressed Memories
Suppressed Memories
2.8. Intelligence and Achievement. Intelligence refers to one’s ability to learn and to solve problems.
a. Theories of Intelligence:
Charles Spearman and the idea of a measurable general intelligence (g factor). Spearman used Factor Analysis.
L.L Thurstone: Clusters of mental ability
Word fluency, verbal comprehension, spatial ability, perceptual speed, numerical ability, inductive reasoning, memory.
Daniel Coleman: Emotional Intelligence
Robert Sternberg: Analytical, Creative, Practical
Raymond Cattel: Fluid and Crystalized Intelligence
Speed of Processing: How fast can you think?
Claude Steele: Stereotype Threat
Flynn effect: IQ scores appear to have been rising steadily since the tests were first given in the early 20th century.
b. Assessing Intelligence: Psychometrics
Tests: Standardized, usually giving a normal curve.
Tests: Reliable—yields the same results over time
Tests: Validity: Test results predicts what they are intended to predict.
Test Types: Achievement Tests (like the AP or EOC, the testing comes after the learning has taken place. Aptitude tests: The ACT and SAT are intended to predict your future success. They are standardized, reliable, and valid.
Alfred Binet: IQ = Mental Age/Chronological Age x 100. A nine year old taking the test and scores near the mean, his or her IQ equals 100.
GRIT: now hard are you willing to work and for how long? What role does grit play in IQ score?
Lewis Terman: recognized that the Binet scores lost all meaning after childhood. Developed the Stanford-Binet test which measures the deviation from the norm rather than a simple ratio.
David Wechsler: The Wechsler Adult Intelligence Scale
Francis Galton and Eugenics: Argued that if intelligence is an inherited trait, then it should be possible to encourage highly intelligent people to reproduce while discouraging people with lower intelligence. His ideas were influential in the US in he early 20th century and in Nazi Germany in the 1930s and 1940s.
IQ tests can be biased to benefit certain groups and discourage others.
The Stereotype threat:
c. Stability of and Influences on Intelligence Intelligence seems to be stable
through adulthood.
d. Group Differences and the Question of Bias
Francis Galton and Eugenics: Argued that if intelligence is an inherited trait, then it should be possible to encourage highly intelligent people to reproduce while discouraging people with lower intelligence. His ideas were influential in the US in he early 20th century and in Nazi Germany in the 1930s and 1940s.
IQ tests can be biased to benefit certain groups and discourage others.
The Stereotype threat:
c. Stability of and Influences on Intelligence Intelligence seems to be stable
through adulthood.
d. Group Differences and the Question of Bias
Biological Basis of Memory
Hippocampus: responsible for the formation of memory; processes explicit memories for storage.
Information moves from the hippocampus for storage elsewhere.
Damage to the left side of the hippocampus impacts memory of verbal information. Damage to the right side impacts visual information.
Sleep in needed for memory consolidation, especially NREM-3 sleep.
Working memory (in the frontal lobes), makes sense of auditory and visual information, links new information to existing information in the Long Term Memory
Implicit Memories: riding a bike, skills that are not communicated verbally.
Explicit Memories: Stuff you know.
The Thalamus: Encodes sensory memories into the short-term memory (pre-frontal cortex and temporal lobes).
Cerebellum: stores implicit memories gained from classical conditioning and conditioned reflexes.
Basal Ganglia: procedural memories (like tying your shoes)
Amygdala: emotional and emotion-laden memories.
Long-term Potentiation: as you practice a skill, the synapses that carry out the skill are strengthened. Learning actually shapes the anatomy of your brain.
Glutamate and acetylcholine: neurotransmitters associated with memory formation.
40 Studies, Readings 13, 14 (Self-fulfilling prophecies, Multiple Intelligences)