Exam #2 Perception
Terms
undefined, object
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- Independent Variables
- 1. stimulus 2. organismic 3. comparative 4. developmental
- Measurement Definitions
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random vs. systematic error
precision vs. accuracy
realiable vs. validity - Psychophysical Methods: Phenomenology
- Looking at what is in consciousness, the meaning of our experiences. Naive: lack of experiences, as given Analytical Introspection: elements of sensory experiences and simple feelings through examining our own
- Psychophysical Methods: Scaling
- Establish order and distance to an attribute. *magnitude estimation *1 & 2 dimensional
- Psychophysical Methods: Fechner's "Classical Psychophysics"
- 4. Threshold Concept (barrier vs. dependent variable). The physical and mental are parallel, barrier=absolute thresholds and dependent variables=relevant quantifiable output of subject. Using light.
- Fechner's Three Techniques:
- 3. Constant Stimuli-experimenter selects the stimulus level for each trial at random, yes/no (less discrete)
- Sources of Variability in Psychophysical Measurements
- 1.stimulus 2.receptor orientation 3.state of nerves 4.subject's attention 5.response error
- Contemporary Variants: Spatial and temporal forced-choice MCS
- Spatial=nature of space and temoral=time related. A subject is presented with a #of spatial/temporal alternatives in each trial, and is forced to choose a location.
- Contemporary Variants: Staircase Versions of ML
- 2. double random staircase tracking-- a.k.a. discrimination ... point the difference between two stimuli is detectable, whether one is heavier than the other.. AL=absolute threshold, IU=interval of uncertainty, PSE=point of equality, DL=difference threshold between two stimuli, JND= mental difference a subject notices in proportion, CE=constant error PSE-Standard
- Signal Detection Theory in Psychophysics
- Current Status of TSD Perception: 1. TSD rarely used in basic research because of experiments are usually the subjects 2. would be valuable w/children, animals 3.TSD when not sure about subject's a)criterion b)understanding c)cooperation 4.too expensive, many observations to make a ROC graph
- Perceptual Functions
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- type a- threshold experiments
- type b= all other phenomenology and scaling
-type a only allows neural inferences
-type b cna inspire a type a experiment - Galen
- Greek physician writing in Rome, 4 bodily humors- blood, yellow bile, black bile, phlegm. Ideas in spirits- animal spirit(brain) for movement/perception/senses -vital spirit (heart) blood/body temp. -natural spirit(liver) nutrition/metabolism..Substances act like what we think of as forces used by humans and dumb brutes to initiate and control actions.
- before 1650 Albertus Magnus
- ventricles
- Before 1650 Leonardo da Vinci
- wax cast of ventricles and shape
- Before 1650 William Harvey
- challenged- circulation, blood flows through the body like tides, pumped from heart. Credited of modern experimental physiology.
- Before 1650 Robert Boyle
- vacuum chamber/air-pump able to carry out a variety of trials aimed to elucidate the air
- Before 1650 Nicolaus Steno
- evaluating the brain in smaller parts
- Before 1650 Leeuwenhoek
- drawing of capillaries
- Nerves
- Carry messages from the brain to muscles. Carry messages from sensors back to the brain. Body of salt water, outside is +, charge is lost when the top end of a nerve cell is stimulated = depolarization, down the cell from the brain to the muscle. Nerve swells out to the muscle, relasing a chemical Acety-choline into the gap between the nerve and muscle. Part of the PNS system. Afferent nerves convey sensory signals to the CNS. While efferent nerves conduct stimulatory signals from CNS to muscles and glands. Most nerves connect to CNS through spinal cord.
- Muscle
- A polarised membrane like nerves. Special receptors built into this membrane, when attached to acetyl-choline to a receptor=depolarised. Muscle contraction occurs without conscious thought and necessary for survival.
- Rene Descartes
- Natural sciences, methodological skepticism: he doubts that any idea can be doubted. Thought exists, cannot be separated from me, I exsist. Thinking the only thing that cannot be doubted, there are limitations to the senses. Skepticism of the external world.
- Giovanni Borelli
- Explain the movements of the animal body on mechanical principles (biomechanics). Testing hypotheses against observation and blood. Microscopy to investigate stomatal movements of plants.
- Jan Swammerdam
- Studied insects and their various phases during life, and different forms of the same animal to muscle contraction, also found red blood cells. He used the microscope in disections and wax injections.