Textbook Notes (362,767)
Canada (158,052)
Psychology (4,729)
Psychology 1000 (1,558)
Prof (29)
Chapter 5

Chapter 5 Notes.docx

5 Pages
Unlock Document

Western University
Psychology 1000

Chapter 5 Notes Synesthesia: “Mixing of the senses” They may experience sounds as colours or tastes as touch sensations that have different shapes. Sensation: The stimulus-detection process by which our sense organs respond to and translate environmental stimuli into nerve impulses that are sent to the brain. Perception: The active process of organizing this stimulus input and giving it meaning. Transduction: The process whereby the characteristics of a stimulus are converted into nerve impulses Psychophysics: Studies relations between the physical characteristics of stimuli and sensory capabilities. Absolute threshold: The lowest intensity at which a stimulus can be detected 50% of the time The lower the threshold, the greater the sensitivity Decision criterion: A standard of how certain they must be that a stimulus is present before they will say they detect it Signal detection theory: Factors that influence sensory judgements Subliminal stimulus: One that is so weak or brief that, although it is received by the senses, it cannot be perceived consciously Difference threshold: The smallest difference between two stimuli that people can perceive 50 percent of the time Weber’s Law: States that the difference threshold, or jnd, is directly proportional to the magnitude of the stimulus with which the comparison is being made It is expressed as Weber fraction The smaller the fraction the greater the sensitivity to differences Sensory adaption: Sensory neurons are engineered to respond to a constant stimulus by decreasing their activity and the diminishing sensitivity to an unchanged stimulus Cornea: Where light waves enter through the eye Iris: Muscles that control the pupil’s size Lens: An elastic structure that becomes thinner to focus on distant objects and thicker to focus nearer objects Retina: A multi layered tissue at the rear of the fluid-filled eyeball Myopia = Near-sightedness Good vision for nearby objects but have difficulty seeing far away objects Lens focuses the visual image in front of the retina, too near the lens, resulting in blurred image for faraway objects Hyperopia = Farsightedness Good vision for faraway objects but have difficulty seeing close-up objects Lens focuses the visual image behind the retina, too far away the lens Common for many middle aged people Rods: Black and white brightness receptors Function best in dim light 500 times more sensitive to light than cones Do not give rise to colour Cones: Colour receptors that function best in bright illumination Fovea: Small area in the centre of the retina that contains only cones Bipolar cells: Synaptic communication with the rods and cones Visual acuity: Ability to see fine detail Blind spot: No photoreceptors Photopigments: Protein molecules that allow rods and cones to travel through light waves into nerve impulses Dark adaptation: The progressive improvement in brightness sensitivity that occurs over time under conditions of low illumination Trichromatic theory: Any colour in the visible spectrum can be produced by some combination of wavelengths that correspond to the colours, blue, green and red This is known as the additive colour mixture Three types of colour receptors in the retina If all three cones are equally activated, a pure white colour is perceived Opponent process theory: Each of the three cone types responds to two different wavelengths Red or green. Blue or yellow. Black or white. Dual-process theory: Combines the trichromatic and the opponent process to account for the colour transduction process The theory used today Dichromat: A person who is colour-blind only to one of the systems Must be either blue-yellow, or red-green Monochromat: Sensitive only to black-white system and is totally colour blind Feature detectors: Groups of neurons within the primary visual cortex that are organized to receive and integrate sensory nerve impulses originating in specific regions of the retina. Frequency: The number of sound waves Measured as cycles per second The higher the frequency the higher the perceived pitch Humans are capable of detecting sounds from 20 up to 20 000 Hz Herts (Hz): The technical measure of cycles per second 1 Hz equals one cycle per second Amplitude: The vertical size of the sounds waves Amount of compression and expansion of the molecules Primary determinant of loudness Decibels (db): Measure of differences in amplitude A measure of the physical pressures that occur at the eardrum Absolute threshold from 0 to 10 db Organ of Corti: 16 000 tiny hair cells that are sound receptors Frequency theory: Nerve impulses sent to the brain match the frequency of the sound wave This holds true for lower frequencies Place theory: The specific point in cochlea where the fluid wave peaks and most strongly bends the hair cells serve as a frequency-coding cue. This holds true for higher frequencies Sound localization: The nervous system uses information concerning the time and intensity differences of sounds arriving at the two ears to locate the source of the sounds in space Conduction deafness: Problems involving the mechanical system that transmits sounds waves to the cochlea Can be helped with the use of a hearing aid Nerve deafness: Caused by damaged receptors within the inner ear or damage to the auditory nerve itself Cannot be helped with the use of a hearing aid Common causes can be machines in factories and loud music Gustation = Taste Olfacti
More Less

Related notes for Psychology 1000

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.