Coping

We use a variety of methods to survive emotionally and physically. We take defensive measures whenever we’re under attack. We react whenever someone yells at, ridicules, or scolds us. It’s not that we don’t have coping skills. The problem is that we don’t select them. Usually we use whatever is at hand. Read more

Day 2: Outline

 

Receptive fields
   Each visual cell has a “hot zone”; place which is more sensitive
   Cells which respond to specific stimuli
      “on” cells = firing when light is on
      “off” cells = brief burst when light goes off
      “on-off” cells = brief burst for on and off 

3 Magnitude Principles
   1. Firing rate increases (to a limit 1,000/sec)
   2. Volley theory = cells fire in a sequence
   3. Other nerves take over (e.g. rods to cones; inner to outer hair cells)

PERCEPTION
   Processes
   Direction
      Bottom-up
         From Light to Brain
              Sun radiates a photon
              Photon = packet of information
              8 minutes later, photon reaches you
      Top-down
         Cognitive influences
         Stroop Effect = say the color you see

Visual System
   Process|
      Selective gathering of light
      Projection or focusing of the light on a photosensitive surface
      Conversion of the light into a pattern of chemical or electrical activity
      Light sources: sun, light bulbs, candles, moon
      Doesn’t matter if an object is a source or a reflector of light
      Strength of reflection is a function of:
         color of object
         smoothness of object
         relative orientation between light rays, surface and observer

Eye
   Photoreceptor = receptor of photons
   Transforms light into nerve impulses
      More light = higher frequency of impulses
      Transducer of light into neural signal
   Perception is hard
      Objects can be hidden or blurred
      Recognize objects from different viewpoints
      Differentiating between objects

Structuralism
   Wilhelm Wundt
      Perception is like chemistry
      Combine elements (sensations); add up the dots
      Problems with structuralism
         Can’t explain apparent motion
         Phi phenomenon 

Gestalt
   Similarity = things moving in same direction go together
   Proximity = see as columns, rows or both
   Connectedness = things that are linked go together
   Common Region = things that are bound together go together
   Figure & Ground
      Figure is always in front of ground
      Ground appears more continuous

Illusions
   Brightness contrast
      Grey square on white background
      Grey square on black background
   Delboeuf Illusion = compare outer to inner
   Estimation = height of 4-story building overestimated by 25%
   Horizontal-Vertical Illusion
      “Horizon line” is perceived as shorter than vertical line
      Seen by people raised with seeing long vistas
      Not seen by eople raised without experience seeing natural horizon
          (Rain Forest People)
   Muller-Lyer Illusion
      Only seen by people raised in a “carpeted” environment
      Not see by those raised without carefully squared off buildings 

TACTILE SENSATIONS
   3 types of tactile sensations
      1. Pressure
         Light
         Deep
      2. Temperature
         Cold
         Warm
         Not hot
      3. Pain
        Sharp
        Dull 

SKIN MAPPING
   4 findings:
      1. Sensations are not continuous across skin
         Localized in discrete points
      2. Number of pain spots > number of pressure > number for temperature
      3. Localization shifts over time
      4. Specific sensations not always directly correspond to type of receptor
             Pressure can be felt as pain 
   Ascending Pathways
      1. Lemniscal System
         Pressure information
         Small receptive fields
         Rapid transmission in long axons
         Travels up the back of the spinal chord
         Travels to somatosensory I in the Parietal lobe
               (front part of parietal lobe)
         SSI is organized into the sensory humunculus
      2. Spinothalamic System (Extralemniscal)
         Pain & temperature information
         Large receptive fields (dermatomes)
         Small axons and slower transmission
         Travels up sides of spinal chord
         Travels to somatosensory II in the parietal lobe
             (back part of parietal lobe)
         SSII does not have a neat organization
             Many overlapping representations 

PERCEPTUAL EXPERIENCES
   Temperature
      Two independent systems
         Cold
        Warm
        Hot is not the extreme of warm 
           Both warm and cold spots respond to “hot” stimuli 
      “Paradoxical cold” = can not distinguish extreme hot from extreme cold
      Physiological zero = current skin temperature
           Things you touch are compared to your current skin temperature 

   Pain
      Sharp and dull pain are independent systems
      Travel in different areas of spinal chord
      Treatment for one not usually effective for the other
         all tactile senses except pain adapt very quickly
      Survival function of pain

   Touch
      Passive touch
         Being touched
         Touch nose & touch knee, which “feels touched”?
      Haptic perception (active touch)
         1. cutaneous receptors lying beneath the skin surface
         2. kinesthetic receptors found in muscles, tendons, and joints
         Use of kinesthetic & tactile info to identify objects
            (blind people and babies)
            Identify 3-D objects with the hand
         Uses both:
           1. cutaneous receptors lying beneath the skin surface
           2. kinesthetic receptors found in muscles, tendons, and joints
         Uses three distinct systems:
            Sensory system
            Motor system
            Cognitive system 

   Flavor is overall, total sensation
   Learned preferences for flavors

Taste & Smell
   The Chemical Senses
   Systems for detecting chemicals
   3 Research Difficulties
      1. Hard to control amount of odorant reaching the smell receptors
      2. Very rapid adaptation
      3. Taste buds die off every 4 – 11 days

   Gustation (Taste)
      Detects chemicals dissolved in a solution
      Saliva helps to dissolve the chemical
      Four taste qualities (sweet, sour, bitter, salty)
      Possible two more: umani (savory; MSG) and fatty acid
      1. Sweet
           Receptors in apical membrane
           Bind glucose
               sucrose = glucose & fructose
               carbohydrates

      2. Sour
          Acid = pH of less than 7
            Vinegar = acetic acid
            Lemon juice = citric acid
            Milk = lactic acid
            Meat = carboxylic acids
         Acid & water combine
            Form hydronium ions (H3O+)
            Detected by hydrogen ion channels
            Hydrogen ions permeating sodium channels
            Hydrogen ions also inhibit potassium channel
            Acid give off H+ ion (protons = H+)
            Proton-sensitive ion channels
            Activates sour-taste receptors
            Cell depolarization
                 decrease in intracellular pH in the cells
                 transmitter release onto gustatory neurons

      3. Bitter
         Receptors release acetylcholine (Ca2+)
         Internal stores; no external Ca2+ needed
         Elevated acetylcholine level fires neighboring neuron

      4. Salty
         Detects sodium chloride (Na+ Cl-)
         Sodium chloride ions enter receptor cells
         Na-channels
            similar to but differ from neuron & muscle sodium channels
         Depolarization causes transmitter release
         Increased firing in neuron

      5. Umani (savory)
         Non-salty MSG
         Food tastes “fuller”
         Detection of glutamate
         Found in meats, cheese, etc.
        1908, Kikunae Ikeda (Tokyo Imperial U)
            researching seaweed broth
            isolated monosodium glutamate
            began commercial distribution of MSG
         Binding activates G-protein
         Ionotropic glutamate receptors on tongue
            When activated, calcium enters cell
            Transmitter release
            Increased firing of adjacent neuron
                Makes all taste receptors more sensitive
                Less taste required to trigger them

      6. Fatty acid
         Linoleic acid
         In lots of vegetables
         Safflower & sunflower oil
        An essential fatty acid: omega-6 fatty acids
        Readily available in most diets
         Only requires a tablespoon of polyunsaturated plant oils per day 

   Tongue
      Tongue contains papillae:
         Filiform – shaped like cones and located over entire surface
         Fungiform – shaped like mushrooms and found on sides and tip
         Foliate – series of folds on back and sides
         Circumvallate – shaped like flat mounds in a trench located at back
      Taste buds
         Tongue contains approximately 10,000 taste buds
         Each taste bud has taste cells with tips that extend into the taste pore
         Transduction occurs when chemicals contact receptor sites on the tips
      Taste pores = where the taste stimulus enters
      Taste cell = tip of the taste cell is just under the pore
          Groups of 30-100 cells
          Elongated “neuroepithelial” cells
          Embedded in papillae
          Epithelium = relatively flat surface (food can’t penetrate)
             Tiny fibers (processes) stick out at tip of bud
             Stick out thru “taste pore”

   Tongue localization
      Entire surface can detect all tastes
      However, small differences
         tip = sweet
         sides = salt and sour
         back (& soft palate) = bitter
   Taste buds are also located in:
      Oral cavity
      Pharynx
      Llaryngeal
      Start of the esophagus

   How Perceive Taste
      Sensory coding
        Firing rate of neurons
        Patterns of neurons
           Activity across many receptors
           Same receptors, different amounts of activity
           Assume four taste buds
              Respond to each taste 

   Olfaction (Smell)
      Detects chemicals in the air
      All smells are small molecules (less than 350 molecular mass)
      Roof of each nostril, called the nasal mucosa
          Contains olfactory epithelium
          Covered with mucus
      Olfactory epithelium
          Contains sensory cells
          Bowman’s glands (make nasal secretions)
      Pigmented epithelial cell
          Deeper the color, more olfactory sensitivity
             Humans = light yellow
             Dogs = brown or dark yellow
         Perhaps absorbs infrared radiation?
         10 million in humans; more in rats and cats
      Receptor cells
         Have dendritic “knob”
         Enlarged terminal
         Projects above epithelium surface
         Contain 10-20 olfactory cilia
             Contain smell receptors
             Cilia don’t move
      Olfactory epithelium
         Odorants are carried along the mucosa
         Come in contact with sensory neurons
         Cilia of sensory neurons contain receptors
         Humans have about 350 types of receptors
             Each has a protein that crosses the membrane 7 times
         Receptor cells are bipolar neurons
               Capable of regenerating

   Flavor
      Not the same as taste
         Apple, onion, and potato have same taste, they differ in flavor
         Durian fruit  
      Composed of: 
         Taste
         Smell
         Touch (texture)
         Temperature
         Color
         Sometimes pain
        Also effected by:
           Hormonal influences 
           Drugs and chemicals 
           Genetic variations
           Age

 

 

Copyright © 2009 Ken Tangen

How To Learn Anything

Here are 10 Tips to help you learn anything. Using them can help you do better in work, school, sports and relationships. These are not study suggestions. They go the core of what learning is. Read more

Tip 1: Avoid (reduce)

The best tip for learning is to avoid it. Or at least, try to reduce it to things that important. You can use this as a general rule for reading books. Try to find one good idea from a book. Just one. If you can find one good idea, it’s well worth the price of the entire book. And you find more than one good idea in a book, think of how valuable that is. Read more

Tip 2: Bits (chunks)

Learning is easier if you divide up the material. Think of it like eating a giant pizza. You do it bite by bite. In learning, long passages can be broken down in smaller segments, long lists can be converted into several smaller lists, and stacks of information can be sorted into small piles. Read more

Tip 3: Chaining

Tip 4: Don’t Forget

It is much easier to keep things in memory than to put them in. So try to avoid relearning. Although it’s impossible to prevent all forgetting, you can work at keeping things in memory. Learn it, store it, test it, and keep it. Read more

Tip 5: Encoding Specificity Principle

Learning works best when the study conditions and the recall conditions match. You know from your own experience that practice sessions are different than performances. Playing the guitar in your bedroom isn’t the same as playing it on stage. Singing in a choir doesn’t prepare you for performing a solo. Playing football in the backyard is not the same as playing it in a gigantic stadium. Read more

Tip 6: Switch Tasks

Pretend memories are boxes with labels on them. Each label describes a particular characteristic of that box. Having lots of labels on one box makes it easier to find. You can search by size, color, contents, etc. Having only a few labels on a box makes it more difficult to find (less search options). Read more

Tip 7: Higher Criteria

We have a tendency to target our energies. We set a goal, determine what needs to be done to achieve that goal, and proceed to execute our plan. It’s a good system. But we don’t do more than is necessary. We are minimalists. We only do what we need to do. Read more

Next Page »