Class Notes (838,116)
Canada (510,680)
Psychology (4,227)
PSY312H5 (118)
Lecture 5

Lecture 5 Perceptual Development PSY312

7 Pages
88 Views
Unlock Document

Department
Psychology
Course
PSY312H5
Professor
Stuart Kamenetsky
Semester
Winter

Description
February 3, 2014 Lecture 5: Perceptual Development -5 senses: smell(olfactory), sight(visual), touch, taste(gustatory), hear(auditory) -incoming sensory information, you adult developed person, able to detect 5 incoming sensations -what are those sensations? -perception -how they develop? -we rely the most on visual sensation -other vertebrates don't rely on visual sensation as much -second most important sensory input is auditory -third most important, involved in evolution, other vertebrates rely on olfactory (smell) -touch is a complex sense, because they are many touch receptors: pain, temperature, pressure, vibration -vestibular system is right behind the ear, balance Principles of Sensation -Transduction; physical energy to neural signal -taking complex information and transducing it into meaningful information that is useful to you (thought- sophisticated and complex) -Absolute threshold-- smallest strength of a stimulus that can be detected -important because the sensory detectors that we have are really sensitive -detect differences in colour, detect things that are really far away using visual system -detecting difference sounds (long and short 'a') -Difference threshold; (jnd) smallest difference that can be detected -somatosensory cortex (touch) -lips and hands -Sensory adaptation -use sensation to adapt to an environment -infants are born legally blind, we rely on it so much as adults but it's the least developed at birth -hearing well developed at birth Vision Purpose of the visual system -transform light energy (protons) into an electrochemical neural response -represent characteristics of objects in our environment such as size, colour, shape and location -electromagnetic radiation (incoming input of vision) - energy -energy occurs in a spectrum, of waves, can be converted into mass, mass can be converted to energy (interchangeable) -energy is frequency(length) waves -visual part of the spectrum is very concise, particular part of that energy spectrum (400-700 February 3, 2014 nHz) -visual system is detecting nanometres - radio waves are really long (driving in a car) -a wave has a hill and a trough -light waves cannot get through the molecules in skin -gamma rays can get through molecules in skin (really short waves of electromagnetic radiation) -they can disrupt the molecules and organs in your skin (radiation poisoning) -visual spectrum don't hurt you -even larger than radio waves are electricity (AC circuits) -people don't want to live beside power source because it causes cancer...no the waves are too long, it cannot get inside of you -frequency, wave length determines colour -amplitude, how high the waves are (tall or short), determines brightness -different receptors that detect colour and contrast -magnocellular system and parvocellular system -system that detect movement, shape, location -separate that detects object, colour -put together at the back of the brain ADD IN LIGHT: THE VISUAL STIMULUS PICTURE - Light: The Visual Stimulus -light can be described as both a particle and a wave -wavelength of a light is the distance of one complete cycle of the wave -visible light has wavelengths from about 400nm to 700nm -wavelength of light is related to its perceived colour -number of waves that occur per second (hertz) -eyeball unable to detect other frequencies, only the narrow band -other species that can detect other frequencies -in through the eye -artificial eye, camera, incoming radiation -front of the eye, protective layer called the cornea, transparent -right behind the cornea, lens, to focus, the lens bends the light to accommodate (the lens changes shape) - muscles attached to lens that accommodate to distance -lens accommodate in infancy not so good -iris: different colours (brown is the most common colour) , also accommodates -iris causes muscles in pupil to dilate -too much incoming electromagnetic radiation can hurt you, so eye accommodates (amplitude -black dot in the middle of the eye is called a pupil (too bright, pupil shrink, too dark, pupil opens, more light- reflexive) February 3, 2014 -accommodate for distance, brightness -pupil is a hole, covered by the cornea, radiation comes through pupil and hits the back of the eye -back of the eyeball, transduction takes place, well developed in infancy but not working very well (back of the eyeball is called retina, which has receptors called rods and cones) -blind spot filled in cognitively by the cortex (behind the retina) -optic disk, optic nerve leaves the eye, (no receptors there) -receptors come in different layers and detect and transduce -3 layers of transducing cells at the back of the eyeball -sensory receptor cells -magnocellular and parvocellular -lights turned off, now detecting contrast -lights on, now see colour, detected by cones, very sensitive to wavelength -part of visual system that develops the soonest is the rods (sensation contrast) -sensation colour not so early -less colour looking out the sides of your eyes -cones focus on central part of visual -more rods on the periphery (sides) of the eyes (high for contrast) -rods develop first (movement, contrast) -connected to the bipolar cells, coordinating sensation from the rods and cones -multiple rods connect to bipolar cells -only one connect to cones -bipolar then connected to ganglion cells, form the optic nerve Difference Between Rods and Cones Cones: -allow us to see in bright light -allow us to see fine spatial detail -different colours Rods: -see in dim light -cannot see fine spatial detail -cannot see different colours Which is more sensitive to electromagnetic radiation, in the 400-700, cones or rods? Rods are very sensitive. Develop earlier than cones -rods more numerous in the periphery, cones more in the central Processing Visual Information -Ganglion cells: neurons that connect to the bipolar cells; their axons form the optic nerve February 3, 2014 -Bipolar cells: neurons that connect rods and cones to the ganglion cells -Optic chiasm: point in the brain where the optic nerves from each eye meet and partially crossover to opposite sides of the brain (inner crosses, the outer doesn't) -chemical in the eye that transducin electromagnetic radiation and changes it into a chemical signal: Rhodopsin -after the optic chiasm it becomes the optic tract Hearing: Sound Waves -Auditory perception occurs when sound waves interact with the structures of the ear -Sound Wave: changes over time in the pressure of an elastic medium (for example, air or water) -without air (or another elastic medium) there can be no sound waves, and thus no sound Are you transducing electromagnetic radiation when you hear? No, not detecting energy, d
More Less

Related notes for PSY312H5

Log In


OR

Join OneClass

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

Sign up

Join to view


OR

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.


Submit