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PSYB51
Chapter 1 & Lecture 1
Question | Answer |
---|---|
Plato's theory of perception and reality? | conception of reality depends on what we can learn about the world through our senses. |
Heraclitus? | Greek philosopher created the metaphor:"you can never step into the same river twice" to explain that no two experiences can be identical b/c experiencing the 1st event changes how we experience the same event a 2nd time and so on. |
Adaptation: | A reduction in response caused by prior or continuing stimulation; perception is quick to ignore anything that stays the same for long. Eg. the olfactory adapts to a strong smell in the room |
Democritus: | believed sensations are caused by collision of atoms; atoms leaving our senses and colliding in sense organs - most reliable senses were those that detect the weight or texture of objects b/c of being in direct contact |
Democritus' primary & secondary qualities: | primary qualities- can be directly perceived (i.e. weight, texture) secondary qualities- require interaction b/w atoms from objects & atoms in the perceiver |
sensory transducer: | A receptor that converts physical energy from the environ. into neural activity; transducers 1st transform info. abt the world into neural signals that can be interpreted by the brain |
Nativism: | idea that the mind produces ideas that are not derived from external sources, & that we have abilities that are innate & not learned |
Rene Descartes: | Argued only humans have mind; considered mind to be quite separate frm body-- mind is unextended (doesn't take up space) & has no space (dualism) |
Descartes similar viewpoint to Plato in regards to | all true ideas must come from the mind and not the senses |
Monism | idea that mind & matter are forms frm, or reducible to, single ultimate substance or principle of being |
Materialism | idea that physical matter is the only reality, & everything incl. the mind can be explained in terms of matter & physical phenomena. Type of monism |
Mentalism | idea that the mind is the true reality & objects exist only as aspects of the mind’s awareness. Type of monism |
Mind-body Dualism | Rene Descartes; idea posits the existence of 2 distinct principles of being in the universe: spirit/soul & matter/body |
Empiricism | idea that experience from the senses is the only source of knowledge |
Thomas Hobbes | only matter existed and rejected the concept of spiritual and religious entities b/c they don’t have matter or bodies. An empiricist. |
Hobbes’ Argument | all knowledge must arise from the senses; rejected nativist ideas of Plato & Descartes |
Hobbes’ Viewpoint | thought memories and were sensory experiences that were old and faded ; b/c of these sensory experiences, he thought imagination was not creative at all thought by him as a decaying sense |
John Locke | tabula rasa “blank slate” on which experience writes. |
John Locke’s Belief | rich experiences of the world around us & subsequent ideas abt that world all begin when the simple stimulation of our sense organs is conveyed to the mind – simple ideas. |
“Simple ideas” | first sensory impressions & thought of as primary qualities. Simple and cannot be divided, these sensory impressions aren’t the same as experiences |
Project Prakash | demonstrated that children can achieve visual proficiency on many tasks despite several yrs. of blindness. |
George Berkeley | studied ways in which perception s/a perception of distance is limited by the info. available to us through our eyes . Convinced everything we know must come from sensory experience; “to be is to be perceived.” |
David Hume | believed that we perceive the world as real as our senses are highly reliable, even if limitations on perception do not permit perception to be completely valid. |
Reliability | refers to the consistency of measurements (eg. Do we get the same answer every time?) |
Validity | refers to the relationship of the measurement to what is measured (eg. A height measurement is not a valid measure of performance in class) |
Hume’s Argument | the world portrayed through our senses seems very real b/c perception is highly reliable |
Gustav Fechner | invented psychophysics & is thought by some to be the true founder of experimental psychology. Best known for his pioneering work relating changes in the physical world to changes in our psychological experiences |
Panpsychism | idea that all matter has consciousness |
Fechner’s panpsychism | extended to include animals and inanimate objects |
Fechner’s Goal | formally describe the relationship b/w sensation (mind) & the energy (matter) that gave rise to the sensation |
Psychophysics | the science of defining quantitative relationships b/w physical & psychological (subjective) events |
Ernst Weber | imp. To Fechner’s work; Weber discovered that the smallest detectable change in a stimulus s/a the weight of an object, is a constant proportion of the stimulus level. Relationship became Weber’s Law. |
Two-point threshold | the minimum distance @ which 2 stimuli (eg. 2 simultaneous touches) are just perceptible as separate |
Weber’s findings | the ability of a subject to detect the difference b/w the standard & comparison weights depended greatly on the weight of the standard. Called the difference required for detecting change in weight the just noticeable difference. |
Difference threshold (JND) | smallest detectable difference b/w 2 stimuli or the min. change in the stimulus that enables it to be correctly judged as different from a reference stimulus |
Weber fraction | constant of proportionality in Weber’s law (eg. 1:40) |
Weber’s law | principle that the JND is a constant fraction of the comparison stimulus. |
Fechner’s law | a principle describing the relationship b/w stimulus & resulting sensation such that the magnitude of subjective sensation increases proportionally to the logarithm of the stimulus intensity (12) |
Absolute threshold | min. amount of stimulation necessary for a person to detect a stimulus 50% of the time (eg. the faintest light or softest touch that can be detected?) |
Method of constant stimuli | requires creating many stimuli w/different intensities in order to find the tiniest intensity that can be detected ; eg. an audio test where you are asked to identify the intensity |
Method of Limits | particular dimension of a stimulus or the difference b/w 2 stimuli is varied incrementally until the participant responds differently (i.e. when sound intensity is ascending or descending to cause overshoot in judgments & identify the threshold) |
Method of Adjustment | the method of limits for which the subject controls the change in the stimulus— seen in daily activities but not usually used to measure thresholds b/c of lack of reliability |
Magnitude Estimation | psychophysical method in which the participant assigns values according to perceived magnitudes of stimuli (i.e. when the doctor asks to rate perceived intensity of pain on a scale of 1 to 10) |
Cross-modality of matching | ability to match the intensities of sensations that come from different sensory modalities; enables insight into sensory differences ( used to measure strength of a stimulus) |
Stevens’ power law | states that the sensation (S) is related to the stimulus intensity (I) by an exponent (b) (eg. sensation might be intensity squared |
Review of Weber’s law | involves clear objective measurement; we know how much the stimulus varied & either subjects can tell the stimulus changed or they cannot. |
Review of Fechner’s law | objective measurements like Weber’s law but the calculation is based on some assumptions abt how sensation works. Assumes that all JNDs are perceptually equivalent which is incorrect. |
Review of Stevens’ law | record the subjects’ ratings & we can check whether those ratings are reasonable & consistent, but there is no way to know whether they are objectively right or wrong. |
Johannes Muller | formulated the doctrine of specific energies, which says that we are aware only of the activity in our nerves & we cannot be aware of the world itself. What is most important is which nerves are stimulated not how they are stimulated |
Doctrine of specific nerve energies | states that the nature of a sensation depends on which sensory fibers are stimulated, not on how fibers are stimulated |
Cranial nerves | 12 pairs of nerves (one for each side of the body) that originate in the brain stem & reach sense organs and muscles through openings in the skull (olfactory, optic, auditory, oculomotor, trochlear, abducens, polysensory) |
Olfactory (I) nerves | conduct impulses from mucous membranes of the nose to the olfactory bulb |
Optic (II) nerves | arise from the retina, & carry visual info. to the thalamus & other parts of the brain |
Auditory (VIII) | 8th pair; connect the inner ear w/the brain, transmitting impulses concerned with hearing & balance. Nerve composed of cochlear nerve & vestibular nerve (aka vestibulocochlear nerve) |
Oculomotor (III) nerves | stimulates all eye muscles except superior oblique muscles and lateral rectus |
Trochlear (IV) nerves | 4th pair; stimulates the superior oblique muscles of the eyeballs |
Abducens (VI) nerves | 6th pair; stimulates the lateral rectus muscle of both eyes |
Cortexes that process info. for the senses | olfaction, visual cortex, & auditory ccortex; cortexes can become polysensory |
Polysensory | blending multiple sensory systems |
Hermann von Helmholtz | all behavior could be explained by only physical forces. Demonstrated that the activity of neurons obeys normal rules of physics & chemistry; was the 1st to effectively measure how fast neurons transmit their signals |
Vitalism | idea that “vital forces” are active w/in living organisms, & these forces can’t be explained by physical processes of matter more generally |
Opthalmoscope | device used directly to look @ the retina, the sheet of blood vessels, receptors, & neurons. |
Helmholtz resonators | each resonator is tuned precisely to a certain frequency of vibration, & when thin end is held @ the ear, listeners can pick out a specific frequency frm a complex sound |
Santiago Ramon y Cajal | insights into the organization of neurons in the brain; b/c of his accuracy, his drawings of neuron organizations are still cited today. |
Synapse | junction b/w neurons that permits information transfer |
Sir Charles Sherrington | demonstrated that the speed of neural transmission decreased @ synapses |
Neurotransmitter | a chemical substance used in neuronal communication @ synapses |
Sir Andrew Huxley & Alan Hodgkin | conducted experiments in which they could isolate a single neuron from the squid & test how the nerve impulse travels across the axon |
Electroencephalography (EEG) | measures electrical activity through electrodes placed on the scalp |
Magnetoencephalography | use of extremely sensitive devices to measure magnetic fields produced by electrical activity in the brain |
Positron emission tomography (PET) | look @ page 26 |
Functional magnetic resonance imaging | researchers measure changes in magnetic activity in hemoglobin, which carries oxygen to the cells. Changes allow us to learn where in the brain neurons are using more oxygen, identifying areas that are most active |