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SUSS PSY 107 PSYCHOLOGY Study Unit 2 (Neuron (7 Important…

- - - - All-or-none principle.
        Refers to the fact that the action potential in the axon occurs either completely or
        not at all.
        
        Resting Potential
        In its normal, resting state, ions inside the axon have a negative electrical charge. But this negative state is easily upset.
        
        Action Potential
        When the cell body becomes excited, it triggers a cascade of events, known as the action potential, that temporarily reverses the charge and causes an electrical signal to race along the axon
  - - - Normal Functions
        The most prevalent inhibitory neurotransmitter in neurons of the CNS
      - Problems Associated with Imbalance
        Anxiety Epilepsy
      - Substances That Affect the Action of This Neurotransmitter
        "Miinor” tranquilizers (e.g., Valium, Librium)
        Alcohol
    - - Normal Functions
        The primary excitatory neurotransmitter in the CNS
        Involved in learning and memory
      - Problems Associated with Imbalance
        excessive glutamate apparently causes brain damage after stroke
      - Substances That Affect the Action of This Neurotransmitter
        PCP (“angel dust")
    - - Normal Functions
        The primary neurotransmitter used by efferent neurons carrying messages from the CNS
        Also involved in some kinds of learning and memory
      - Problems Associated with Imbalance
        Certain muscular disorders
        Alzheimer’s disease
      - Substances That Affect the Action of This Neurotransmitter
        Nicotine, Botulism toxin, Curare, Atropine, Barbiturates
    - - Problems Associated with Imbalance
        Lowered levels resulting from opiate addiction
      - Normal Functions
        pleasurable sensations and control of pain
      - Substances That Affect the Action of This Neurotransmitter
        Opiates: opium, heroin, morphine, methadone
    - - Substances That Affect the Action of This Neurotransmitter
        Tricyclic antidepressants Beta-blockers
      - Problems Associated with Imbalance
        High blood pressure Depression
      - Normal Functions
        Used by neurons in autonomic nervous system and by neurons in almost every region of the brain
        Controls heart rate, sleep, stress, sexual responsiveness, vigilance, and appetite
    - - Problems Associated with Imbalance Depression Certain anxiety disorders Obsessive–compulsive disorder
      - Substances That Affect the Action of This Neurotransmitter
        Fluoxetine (Prozac) Hallucinogenics (e.g., LS
      - Normal Functions
        Regulates sleep and dreaming, mood, pain, aggression, appetite, and sexual behavior
    - - Problems Associated with Imbalance
        Schizophrenia Parkinson’s disease
      - Substances That Affect the Action of This Neurotransmitter
        Cocaine Amphetamine Methylphenidate (Ritalin) Alcohol
      - Normal Functions
        A transmitter used in brain circuits that produces sensations of pleasure and reward
        Used by CNS neurons involved during voluntary movement
  - - - Agonists
        
        Drugs or other chemicals that enhance or mimic the effects of neurotransmitters.
        
        Have a excitatory effect on neural pathways making certain neurotransmitters readily available.
        
        For example antidepressant Prozac (fluoxetine) acts as an agonist in the brain’s serotonin pathways, where it makes more serotonin available
      - Antagonists
        
        Drugs or other chemicals that inhibit the effects of neurotransmitters.
        
        They interfere with the neurotransmitters, reducing the stimulation
- - - - Somatic Nervous System
        A division of the PNS that carries sensory information from sense organs to the CNS and also sends
        voluntary messages to the body’s skeletal muscle
        
        Sensory Nervous System (Afferent)
        Sends information from the sense organs to the CNS.
        
        Motor Nervous System (Efferent)
        Sends information from the CNS to the relevant muscles in responses to information received from Sense Nervous System.
      - Autonomic Nervous System
        The portion of the peripheral nervous system that sends information between the CNS and the internal organs and glands.
        
        Parasympathetic Division
        The part of the autonomic nervous system that monitors the routine
        operations of the internal organs and returns the body to calmer functioning after arousal by the sympathetic division.
        Though it has an opposing action, the parasympathetic division works cooperatively with the sympathetic system.
        
        Sympathetic Division
        The part of the autonomic nervous system that sends messages to internal
        organs and glands that help us respond to stressful and emergency situations. AKA the “fight-or-flight” system.
- - - - The Hippocampus and Memory
        
        A component of the limbic system involved in establishing long-term memories.
        
        Grows with experience.
      - The Hypothalamus and Control over Motivation
        
        A limbic structure that serves as the brain’s blood-testing laboratory, constantly monitoring the blood to determine the condition of the body.
        
        Responsible for maintaining the body in a stable, balanced condition,
        
        Serves as the link between the nervous system and the endocrine system, through which it regulates emotional arousal and stress.
        
        Host some of the brain’s reward circuits, especially those that generate the feel-good emotions.
      - The Amygdala and Emotion
        
        A limbic system structure involved in memory and emotion, particularly fear and aggression.
    - - Frontal Lobes
        Involved in thinking and in movement. Also contains mirror neurons which fires in response to (“mirroring”) observation of another person’s actions or emotions.
        
        Prefrontal Cortex
        
        Responsible for advanced mental functions, such as decision making, goal setting, and follow-through, and anticipating future events
        
        Contains biological underpinnings of personality, temperament, and our sense of “self”
        
        Motor Cortex
        
        Controls voluntary movement.
      - Parietal Lobes
        
        Involved in touch sensation
        and in perceiving spatial relationships.
        
        Right parietal lobe
        
        Help us locate, in three-dimensional space, the positions of external objects detected by our senses.
        
        Left parietal lobe.
        
        Specializes in mathematical reasoning and locating the source of speech sounds, as when someone calls your name.
        
        It also works with the temporal lobe to extract meaning from speech and writing.
        
        Somatosensory Cortex
        
        Serves as the primary processing area for the sensations of touch, temperature, pain, and pressure from all over the body
        
        Relates this information to a mental map of the body to help us locate the source of these sensations.
      - Occipital Lobes
        
        House the visual cortex which constructs ongoing images of the world around us.
      - Temporal lobe
        
        Helps make sense of sounds.
        
        Left auditory cortex helps process the meaning of language.
        
        Right temporal helps in interpreting the emotional tone of language.
      - Brain Hemispheric Specialization
        Both hemispheres have different but complimentary processing styles.
        
        Left Hemisphere
        
        Groups object analytically and verbally.
        
        More analytic and sequential
        
        For example - grouping ojects by similarity in function (knife with spoon)
        
        Right Hemisphere
        
        Match things by form or visual pattern
        
        Interprets experience more holistically, emotionally, and spatially
        
        For example - matching coin to clock, which are both round objects
        
        Understanding Split brain patient
        
        First, remember that the corpus callosum enables communication between the hemispheres—so, when it is severed, each hemisphere must process information on its own. This explains, also, why split-brain patients can simultaneously draw a circle with one hand and a square with the other
        
        Because the sensory pathways cross over to the opposite side as they ascend to the cortex, each side of the body communicates with the opposite side of the brain. So, each hemisphere perceives touch sensation from the hand on the opposite side of the body.
        
        Language is usually a left-hemisphere function. This, when combined with the contralateral sensory pathways, explains why these patients could name objects when they were processed in the left hemisphere. When sensory messages came in from the right visual field or the right hand (such as holding the ball in the right hand), the message crossed over to the left hemisphere, which— thanks to its language abilities—could name the object. Conversely, objects seen in the left visual field or felt in the left hand crossed over to the right hemisphere for processing, where—because the right hemisphere cannot produce speech—patients could not name the object. They could, however, identify it by touch.
        
        Cerebral Dominance.
        
        The tendency of each brain hemisphere to exert control over different functions, such as language or perception of spatial relationships.
        
        While it is true that some processes are more under the control of the left hemisphere and others are predominantly right-hemisphere tasks, both hemispheres continually work together to produce our thoughts, feelings, and behaviors—courtesy of the corpus callosum and its role in communication between the hemispheres.
    - - Pons
        
        Regulates brain activity during sleep and dreaming.
        
        Acts as a “bridge” that connects the brain stem to the cerebellum.
      - Reticular Formation
        
        A pencil-shaped structure forming the core of the brain stem.
        
        The reticular formation arouses the cortex to keep the brain alert and attentive to new stimulation.
        
        Monitors the incoming stream of sensory information and directing attention to important messages.
      - Medulla
        
        Controls breathing and heart rate.
        
        The sensory and motor pathways
        connecting the brain to the body cross in the medulla.
      - Thalamus
        
        The brain’s central “relay station,” situated just atop the brain stem.
        
        Nearly all the messages going into or out of the brain pass through the thalamus (except smell).
        
        Acts like the central processing chip in a computer, directing the brain’s incoming and outgoing sensory and motor traffic.
      - Cerebellum
        
        The “little brain” attached to the brain stem. The cerebellum is responsible for coordinated movement.
        
        Help us keep a series of events in order, i.e when listening to the sequence of notes in a melody -
        
        Involved in a basic form of learning that involves habitual responses we perform on cue—i.e when you learn to wince at the sound of the dentist’s drill
        
        Also involved in body balance and muscular coordination
- - - - Transduction.
        
        Transformation of one form of information into another—especially the transformation of stimulus information into nerve signals by the sense organs.
        
        The senses.
        
        Sight
        
        Transduction of Light in the Retina
        
        Incoming light passes through the eye lens, to the ganglion cells and bipolar cells before striking the photoreceptors at the back of the eyeball.
        
        Once stimulated, the rods and cones then transmit information to the bipolar cells (note that one bipolar cell combines information from several receptor cells).
        
        The bipolar cells then transmit neural impulses to the ganglion cells. Impulses travel from the ganglia to the brain via axons that make up the optic nerve.
        
        How the Visual System Creates Colour
        
        Trichromatic theory
        
        based on 3 cone receptors
        
        explains initial stages of color vision
        
        Opponent-process theory
        
        colours in complementary pairs
        
        based on bipolar cells
        
        explains afterimages
        
        Afterimages
        
        Sensations that linger after the stimulus is
        removed
        
        Hearing
        
        How We Hear Sound Waves
        
        Vibrating airborne sound waves are relayed to the inner ear, namely the cochlea.
        
        The cochlea focuses the vibrations on the basilar membrane which is a thin strip of tissue containing haircells connected to neurons.
        
        The swaying of tiny hair cells on the vibrating basilar membrane stimulates sensory nerve endings connected to the hair cells. The excited neurons, then, transform the mechanical vibrations of the basilar membrane into neural activity.
        
        Finally, the neural messages travel to the auditory cortex in the brain
        
        Smell
        
        How we smell.
        
        Biologically, the sense of smell, or olfaction, begins with chemical events in the nose. There, odors in the form of airborne chemical molecules interact with receptor proteins associated with specialized nerve cells.
        
        These cells, incidentally, are the body’s only nerve cells that come in direct contact with the outside environment.
        
        Olfactory bulbs lie very close to, and communicate directly with, structures in the limbic system and temporal lobes that are associated with emotion and memory.
        
        Taste
        
        Registering taste.
        
        The taste receptor cells, located in the taste buds on the top and side of the tongue, sample flavors as food/drinks pass by on the way to the stomach. These taste receptors cluster in small mucous-membrane projections called papillae. Each is especially sensitive to molecules of a particular shape.
        
        Moving beyond the receptors on the tongue, a specialized nerve carries nothing but taste messages to specialized regions of the cortex. There, tastes are realized in the parietal lobe’s somatosensory area.
        
        Touch
        
        Skin senses.
        
        The skin contains nerve endings that, when stimulated, produce sensations of touch, pain, warmth, and cold.
        
        Skin senses are connected to somatosensorysory cortex located in the brain’s parietal lobe
        
        The skin’s sensitivity to stimulation varies tremendously over the body, depending in part on the number of receptors in each area.
        
        Sensory threshold
        
        Two Types
        
        Absolute threshold
        
        Amount of stimulation necessary for a stimulus to be detected
        
        Difference threshold or Just noticeable difference
        
        the Smallest amount by which a stimulus can be changed and the difference be detected (also called just noticeable difference – JND)
        
        Weber’s law
        
        The size of the just noticeable difference – JND is logarithmically proportional to
        the intensity of the stimulus (not linear propportional)
        
        i.e. The JND is always large when the stimulus intensity is high, and small when the stimulus intensity is low
        
        Signal Detection Theory
        
        Perceptual judgment as a result of the combination of sensation and decision-making processes
        
        Steps as follow:
        
        Stimulus
        
        Neural activity
        
        Comparison with personal standard
        
        Action (or no action)
  - - - Top-down Processing
        
        A perceptual analysis that emphasizes the perceiver’s expectations, concept memories, and other cognitive factors, rather than being driven by the characteristics of the stimulus. “Top” refers to a mental set in the brain which stands at the “top” of the perceptual processing system.
        
        i.e Trying to find your car keys in a cluttered room
        
        Perceptual Constancies
        
        An example of Top-Down Processing.
        
        The ability to recognize the same object as remaining “constant” under different conditions, such as changes in illumination, distance, or location
        
        i.e We know a door frame is rectangular in shape even though our sensory image of it is distorted when viewing from an angle.
        
        Colour constancy, which allows us to see a flower as being the same colour in the reddish light of sunset as in the white glare of midday.
        
        Size constancy allows us to perceive a person as the same size at different distances and also serves as a strong cue for depth perception.
        
        Depth Perception
        
        Binoculars cues
        Information taken in by both eyes that aids in depth perception, including binocular convergence and retinal disparit
        
        Retinal Disparity
        
        Arises from the difference in perspectives of the two eyes.
        
        To see how this works, hold a finger about 12 inches from your face and look at it alternately with one eye and then with the other. Notice how you see a different view of your finger with each eye.
        
        We see greater disparity when looking at nearby objects than we do when viewing distant objects, these image differences coming from each eye provide us with depth information.
        
        Binocular Convergence
        
        Suggests how the lines of vision from each eye con-verge at different angles on objects at different distances.
        
        This can be felt when the eye muscles change to foucs on objects at a distance.
        
        Monocular Cues
        Information about depth that relies on the input of just one eye—includes relative size, light and shadow, interposition, relative motion, and atmospheric perspective.
        
        light and shadow
        Lighter-colored objects seem closer to us, and darker objects seem farther away. Thus, light and shadow work together as a distance cue.
        
        Interposition.
        We assume that closer objects will cut off our vision of more distant objects behind them, a distance cue known as interposition. So we know that partially hidden objects are more distant than the objects that hide them. You can see this effect right in front of you now, as your book partially obscures the background, which you judge to be farther away.
        
        linear perspective
        If you have ever looked down a long, straight railroad track, you know that the parallel rails seem to come together in the distance—See Ponzo illusion. This illustrates how linear perspective, the apparent convergence of parallel lines, can serve as a depth cue.
        
        Relative Size
        
        If two objects that are assumed to be the same size cast different-sized images on the retina, observers usually judge them to lie at different distances.
        
        i.e.The guy seating beside you in the lecture hall appears to be bigger due to relative size as compared to the guy seating at the far end of the lecture hall.
        
        Relative Motion.
        As you move, objects at different distances appear to move through your field of vision at a different rate or with a different relative motion. Look for this one from your car window. Notice how the power poles or fence posts along the road-side appear to move by at great speed, while more distant objects stay in your field of view longer, appearing to move by more slowly.
        
        Atmospheric Perspective.
        Haze or fog makes objects in the distance look fuzzy, less distinct, or invisible, creating another learned distance cue called atmospheric perspective.At familiar airports, most pilots have identified a landmark three miles away. If they cannot see the landmark, they know that they must fly by relying on instruments.
        
        Shape constancy that allowed us to see the door as remaining rectangular from different angles.
        
        Gestalt theory of perceptual organisation
        
        Argued that the brain is innately wired to perceive not just stimuli but also patterns of stimulation. They called such a pattern a Gestalt.
        
        Thus, from the raw material of stimulation, the brain forms a perceptual whole that is more than the mere sum of its sensory parts This perspective became known as Gestalt psychology.
        
        The Gestaltists liked to point out that we perceive a square as a single figure rather than merely as four individual lines. An example of our perception of the overall patterns.
        
        The Gestalt Laws of Perceptual Grouping
        The Gestalt principles of similarity, proximity, continuity, and common fate. These “laws” suggest how our brains prefer to group stimulus elements together to form a percept.
        
        Law of Continuity
        The Gestalt principle that we prefer perceptions of connected and continuous figures to disconnected and disjointed ones.
        
        Law of Proximity
        The Gestalt principle that tend to group objects together when they are near each other.
        
        Law of Common Fate
        The Gestalt principle that we tend to group similar objects together that share a common motion or destination.
        
        Law of similarity
        The Gestalt principle that we tend to group similar objects together in our perceptions.
        
        Law of Prägnanz
        The most general Gestalt principle, which states that the simplest organization, requiring the least cognitive effort, will emerge as the figure. Our perceptual system prefers to see a fully developed Gestalt, such as a complete circle as opposed to a broken circle.
        
        Law of Closure
        The Gestalt principle that identifies the tendency to fill in gaps in figures and to see incomplete figures as complete.
        
        Figure and ground
        
        Most basic of perceptual processes identified by Gestalt psychology divides our perceptual experience into figure and ground.
        
        Figure
        The part of a pattern that commands attention. The figure stands out against the ground.
        
        Ground
        The part of a pattern that does not command attention; the background
      - Bottom-up Processing
        
        A perceptual analysis that emphasizes characteristics of the stimulus, rather than our concepts and expectations. “Bottom” refers to the stimulus, which occurs at step one of perceptual processing.
        
        i.e Trying to identify the colour of an object
      - illusion: Definition
        
        An experience when your mind deceives you by interpreting a stimulus pattern incorrectly.
        
        Such errors can occur as a result of applying learned principles of visual perception to ambiguous events.
        
        Why study illusions
        To better understand the fundamental properties of sensation and perception.
        
        How do illusions provide clues to perceptual mechanisms.
        
        Illusions provide clues to perceptual mechanisms because processing directly affected by the stimulus input is usually described as bottom-up processing; top-down processing is influenced by the individual's expectations and knowledge rather than the stimulus itself.
        
        In the case of illusion, our minds are attempting to process the stimuli both from a top-down and bottom up perspective