PSYC2218 Chapter Notes - Chapter All: Posterior Grey Column, Color Space, Normal Lens
CHAPTER ONE – INTRODUCTION
Sensation
- Ability to detect a stimulus & turn that detection into a private experience
Perception
- Act of giving meaning to a detected sensation
Methods used to study senses
1. Thresholds
- Faintest sound you can hear
- Loudest sound you can hear safely
2. Scaling (Measuring private experience)
- Are our eperiees the sae as soeoe else’s?
3. Signal detection theory (Measuring difficult decisions)
- Eg. Determining if a tumor is cancerous
4. Sensory neuroscience
- Ways in which sensory receptors & nerves undergird your perceptual experience
5. Neuroimaging
- Brain imaging techniques enable us to see traces of that experience as it takes
place in the brain
Dualism
- Mind and body are separate
Materialism
- The idea that the only thing that exists is matter
- Mind and consciousness are results of interactions between bits of matter
Panpsychism
- Mind exists as property of all matter
Just noticeable difference
- Difference threshold
➢ Smallest change in a stimulus that can be detected
- Absolute threshold
➢ Minimum intensity of a stimulus that can be detected
Phychophysical Methods
- Method of constant stimuli
➢ Creating many stimuli w diff intensities in order to find the tiniest intensity
that can be detected
- Method of limits
➢ Tones are presented in ascending order from faintest to loudest
- Method of adjustment
➢ Subject steadily increases / decreases intensity of stimulus
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Magnitude estimation
- Participant assigns values according to perceived magnitudes of stimuli
Cross-modality matching
- Observer adjusts stimulus of one sort to match perceived magnitude of a
stimulus of completely diff sort
Signal detection theory
- Quantifies response of observer to the presentation of a signal in presence of
noise
- Internal noise
➢ Static in nervous system
➢ Detect faint sound / flash of light in presence of internal noise
- Criterion level of response
➢ Response in nervous system exceeds that criterion, you will jump out of the
shower to answer the phone
Sensitivity
- A value that defines the ease w which an observer can tell the diff between the
presence & absence of a stimulus or the diff between 2 stimuli
Spatial frequency
- No. of these light / dark hages aross degree of perso’s isual field
- Cycles per degree
➢ No. of pairs of dark & bright bars per degree of visual angle
Cranial nerves
- 12 pairs of nerves (one of each side of body) that originate from brain stem &
reach sense organs & muscles through openings of skull
- 3 exclusively dedicated to sensory info
➢ Olfactory, Optic, Vestibulocochlear
- 3 more dedicated to muscles that move eyes
➢ Oculomotor, Trochlear, Abducens
Neural firing
- Electrochemical
- Voltage increases along axon caused by changes in membrane of neuron that
permit Na+ to rush very quickly into axon from outside
- Pushes K+ out of axon, restoring neuron to its intial resting voltage
Electroencephalography (EEG)
- Measures electrical activity through dozens of electrodes placed on scalp
- To roughly localize whole populations of neurons & measure their activities w
excellent temporal accuracy
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Magnetoencephalography (MEG)
- Good measure of timing of populations of neurons while providing better idea of
where in brain neurons are most active
- More complex and expensive than EEG
Computed tomography (CT)
- Put it tgt to create 3D picture of head
Magnetic resonance imaging (MRI)
- Very powerful magnetic field that influences the way atoms spin
Functional magnetic resonance imaging (fMRI)
- Activated neurons provoke increased blood flow
Positional emission tomography (PET)
- Small amount of safe, biologically active, radioactive material is introduced into
partiipat’s loodstrea
CHAPTER TWO – THE FIRST STEPS INTO VISION: FROM LIGHT TO NEURAL SIGNALS
Cornea
- Transparent bc made of highly ordered arrangement of fibres & contains no
blood vessels / blood which would absorb light
- Rich supply of transparent sensory nerve endings
➢ Force eyes to close & produce tears if cornea is scratched
Aqueous humor
- Fluid derived from blood fills space directly behind cornea
- Supplies oxygen & nutrients to & removing waste from cornea and lens
Iris (Muscular structure)
- Gives eye its distinctive color & controls size of pupil
- Pupil
➢ Hole in iris
- When level of light increases / decreases, iris automatically expands / contracts
to allow more / less light into eye
Vitreous humor
- Transparent fluid that fills vitreous chamber in posterior part of eye
Myopia (Nearsightedness)
- Image falls in front of the retina
- Corrected with negative lenses
Hyperopia (Farsightedness)
- Image falls behind retina
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find more resources at oneclass.com
Document Summary
Ability to detect a stimulus & turn that detection into a private experience. Act of giving meaning to a detected sensation. Loudest sound you can hear safely: scaling (measuring private experience) Are our e(cid:454)perie(cid:374)(cid:272)es the sa(cid:373)e as so(cid:373)eo(cid:374)e else"s: signal detection theory (measuring difficult decisions) Determining if a tumor is cancerous: sensory neuroscience. Ways in which sensory receptors & nerves undergird your perceptual experience: neuroimaging. Brain imaging techniques enable us to see traces of that experience as it takes place in the brain. The idea that the only thing that exists is matter. Mind and consciousness are results of interactions between bits of matter. Mind exists as property of all matter. Smallest change in a stimulus that can be detected. Minimum intensity of a stimulus that can be detected. Creating many stimuli w diff intensities in order to find the tiniest intensity that can be detected. Tones are presented in ascending order from faintest to loudest.
