psychology session 9 - university of toronto · sensation and relaxation • sensory rooms were...
TRANSCRIPT
Psychology
Session 9Sensation and Perception
Date: November 4th, 2016
Course instructor: Cherry Chan
Mothercraft College
Agenda
1. Sensation and perception
2. Vision
3. Perceptual organization
4. Sound
5. Smell
6. Taste
7. Touch
What is sensation and
perception?
• Sensation: detecting external stimuli and
sending those stimuli to the brain
• Perception: internal representations of
external stimuli
(Wood, Wood, Boyd, Wood, & Desmarais, 2017)
Sensation and Relaxation • Sensory rooms were first developed for patients
with cognitive impairments, learning disabilities,
dementia, and young children with complex
disabilities.
• Staff and patients have reported an increase
state of relaxation, lower levels of distress, and
psychological and physiological improvements.
(Smith & Jones, 2014)
• Multisensory environment relaxes students and
provides opportunities for students to focus on
particular activities (Stephenson & Carter, 2011)
Signal detection theory
• Detecting a stimulus against a background
“noise” (Wood et al., 2017).
• A signal is detected based on subjective
experience.
• It is a sensory process, depending on the
intensity of the stimulus, and a decision
process, influenced by the individual’s bias (Wade, Tavris, Saucier, & Elias, 2014).
Figure 1. Responses in Signal Detection. Adapted from Psychology (p.194) by C. Wade, C. Tavris, D. Saucier, and L. Elias, 2014.
Sensing without perceiving
• Selective attention: focus on certain
aspects of the environment and block out
others
• Inattentional blindness: unable to
consciously perceive something you are
looking at because you are not paying
attention to it (Wade et al., 2014)
Vision
• Cornea: bending the light towards pupil
• Pupil: opening where light enters eye
• Iris: muscles contract and dilate pupil
• Lens: focus objects onto retina
• Retina: membrane that contains light-
sensitive receptor cells (rods and cones)(Wood et al., 2017)
Figure 2. Major Structures of the Eye. Adapted from Psychology (p.198) by C. Wade, C. Tavris, D. Saucier, and L. Elias, 2014.
Nearsightedness vs
farsightedness
Figure 3. Normal, nearsightedness, and farsightedness. From Normal,
nearsightedness, and farsightedness by Lusby (2013) Retrieved fromhttp://www.nlm.nih.gov/medlineplus/ency/imagepages/19511.htm
Rods and cones
Figure 4. Differences between Rods and Cones. Adapted from Psychology (p.199) by C. Wade, C. Tavris, D. Saucier, and L. Elias, 2014.
Cones
Figure 5. Three types of cones. From Seeing colour by Arizona State
University (2010) Retrieved from http://askabiologist.asu.edu/rods-and-cones
What’s wrong with this child?
Figure 6. Scheibe illusion. From Upside-down optical illusions again by Vurdlak
(2008) Retrieved from http://www.moillusions.com/2008/03/upside-down-
optical-illusion-again.html
Perceptual
organization
Figure 7. Gestalt grouping principles.
From Perception by Diane (2010)
Retrieved from
http://www.rhsmpsychology.com/Ha
ndouts/Gestalt_grouping.htm
Perceptual constancy
• An object has stable properties regardless
of distance, viewing angle, and lighting.
– Size
– Brightness
– Colour
– Shape
(Wood et al., 2017)
Size
Figure 9. In the left panel, the man in the background appears to be about the same height as the
woman in the foreground From Do artists see their retinas? by Perdreau & Cavanagh (2011)
Retrieved from http://c431376.r76.cf2.rackcdn.com/12334/fnhum-05-00171-
HTML/image_m/fnhum-05-00171-g001.jpg
Brightness
Figure 10. Brightness constancy. From Accuracy and inaccuracy in perception by Fong
(2011) Retrieved from
http://students.flatworldknowledge.com/bookhub/10145?e=stangor-ch04_s05
Colour
Figure 11. Colour constancy. From Colour constancy in perception by Gurney
(2010) Retrieved from http://gurneyjourney.blogspot.fr/2010/01/color-
constancy.html
Depth cues
• Binocular depth cues
– Convergence: focusing on nearby objects by
turning eyes inward
– Binocular disparity: differences between two
retinal images
(Wood et al., 2017)
Monocular depth cues
• Interposition: One object blocking the view of another
• Linear perspective: parallel lines come closer
together when they recede into distance
• Relative size: larger objects are closer
• Texture gradient: fuzzy objects are further away
• Atmospheric perspective: blurry and bluish-tint
objects are further away
• Shadow or shading: light creates shadows
• Motion parallax: when you are moving, objects move
in the opposite direction and at different speeds (Wood et al., 2017)
Impossible figures
Figure 12. Elephant feet. From Cognitive illusions by World Mysteries (2011)
Retrieved from http://www.world-mysteries.com/illusions/sci_illusions3.htm
Context and perception
Figure 13. The Cat. From Context effect by Wikipedia (2013) Retrieved from
http://upload.wikimedia.org/wikipedia/commons/3/3a/TheCat.png
Sound• Frequency: the pitch of the sound
• Amplitude: intensity of sound
– A cue for sound distance
• Timbre: sound quality
• Our two ears helps to discern sound
direction
– i.e. sound coming from the right will reach the
right ear a fraction of a second before the left
ear
(Wade et al., 2014; Wood et al., 2017)
Figure 14.Major Structures of the Ear. Adapted from Psychology (p.213) by C. Wade, C. Tavris, D. Saucier, and L. Elias, 2014.
Kinesthetic and vestibular
• Kinesthetic sense: body position
• Vestibular sense: movement
(Wood et al., 2017)
Figure 15. Balance disorder illustration.
From Semicircular canal by
Wikipedia (2013) Retrieved from
http://upload.wikimedia.org/wikipedi
a/commons/3/33/Balance_Disorder
_Illustration_A.png
Smell
Figure 16. Receptors for Smell. Adapted from Psychology (p.218) by C. Wade, C. Tavris, D. Saucier, and L. Elias, 2014.
A Taste Test
Figure 17. Taste Test. Adapted from Psychology (p.217) by C. Wade, C. Tavris, D. Saucier, and L. Elias, 2014.
Touch and pain
• Tactile information is transmitted to the brain
when an object touches and depresses the skin.
• Nerve endings in the skin send signals to the
somatosensory cortex in the parietal lobe.
• Two point threshold: the distance between two
points of stimulation before a person is able to
feel two separate points of contact.
• Endorphins relieve pain and promote positive
mood
(Wood et al., 2017)
ReferencesSmith, S., & Jones, J. (2014). Use of a sensory room on an intensive
care unit. Journal of Psychosocial Nursing and Mental Health
Services, 52(5), 22-30.
Stephenson, J., & Carter, M. (2011). The use of multisensory
environments in schools for students with severe disabilities:
Perception from teachers. Journal of Developmental and Physical
Disabilities, 24(1), 95-109.
Wade, C., Tavris, C., Saucier, D., Elias, L. (2014). Psychology (4th
Canadian ed., DSM-5 Update ed., 4th ed.). Toronto, ON: Pearson
Education Canada.
Wood, S.E., Wood, E.G., Boyd, D., Wood, E., & Desmarais, S. (2017).
The world of psychology (7th Canadian ed). Toronto, ON: Pearson
Canada