PSYC 367 Sensory Systems

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PSYC 367Sensory Systems

• Dr. Debbie Giaschi
• (pronounced Jawski)

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Fraser Spiral
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visual illusion a discrepancy between what is
perceived and what is physically present in the
real world
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x
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complementary afterimages
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The Hermann grid
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simultaneous brightness contrast
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colour assimilation
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optical illusion a discrepancy between what is
in the retinal image and what is present in the
real world
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moon illusion
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Aristotles illusion
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COURSE OUTLINE
PSYCHOLOGY 367(001) Sensory
Systems
Term 1, 2009W Instructor Dr.
Debbie Giaschi office Kenny 2531 phone
875-2345x7807 e-mail giaschi_at_interchange.ubc.
ca Teaching Assistants Matt Dixon Marita
Partanen John Secen office Kenny Kenny
3606 Kenny 3606 All questions about exam grading
and results should be directed to the TAs.
Office Hours Dr. Giaschi Tuesday, 1245-145
pm John Wednesday, 1000-1100 am Matt
Wednesday, 230-330 pm Marita Thursday,
930-1030 am We are also easily reached by
e-mail at psyc367ubc_at_gmail.com. We will check
this account daily so please send all questions
about course content, assignments and exams here.
Textbook Sensation Perception, 2nd edition
(2009) by Jeremy Wolfe et al.
e-book details www.sinauer.com/ebooks/wolfe2e
textbook demos www.sinauer.com/wolfe2e
website www.giaschilab.ca/psyc367main.html (You
will find the course syllabus, instructional
objectives, lecture outlines, lecture slides and
grades at this site)
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Lecture Outline available at
www.giaschilab/psyc367main.html 1.
Demonstrations of cool perceptual stuff Fraser
spiral complementary afterimages Hermann grid
simultaneous brightness contrast colour
assimilation Aristotles illusion naturally-occur
ring illusions (eg. moon illusion) 2. Overview
of course course syllabus 3.
Introduction -steps in perception (physical
stimulus, physiological response, sensory
experience) -broad questions to be examined in
this course 1) What is the relationship between
the stimuli reaching the receptors and the events
inside the person? 2) What is the relationship
between the events occurring inside the person
and the persons perception? 3) What is the
relationship between the stimuli reaching our
receptors and our perception? 4. Early
philosophy of perception -Heraclitus world is
continually changing effect of experience,
adaptation -Plato perception determines reality
evolution, species differences -Democritus
perception reflects reality sensory
transducers 5. Nativism and empiricism -Descartes
mind-body dualism vs. monism (materialism,
mentalism) -Hobbes, Locke, Berkeley, Hume
perception depends on experience
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Readings and Lectures
Grades Midterm Exam 40 Final Exam 40 Research
Projects 20 total 100
Exams Oct 27 Dec TBA
Research Projects internet experiments due Sept
22 group sign up Sept 22
individual proposal due Sept 29 group
planning Oct 8 (in class) group
experiment Oct 15 (in class) group
analysis/slides Oct 29 (in class)
slides due Nov 5 individual report
due Nov 17

Subject pool participation up to 3 bonus marks
hsp.psych.ubc.ca
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INSTRUCTIONAL OBJECTIVES

• By the end of the class, you will be able to
• 1. Describe at least one artificial and one
  real-world situation in which the information
  from our senses is not reliable.
• Describe the steps in the perceptual process.
• List the 3 relationships to be studied in this
  course and the techniques available to study each
  relationship.
• Summarize the viewpoints of the 3 Greek
  philosophers and discuss their influence on
  modern ideas about perception.
• Distinguish between nativism and empiricism,
  dualism and monism, materialism and mentalism.

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physical stimulus
physiological response
sensory experience
eg. light, sound, odour
pattern of electrical activity in sensory
receptors, nerves, brain
eg. see something, hear something, smell something
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physical stimulus
physiological response
sensory experience
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1) What is the relationship between the stimuli
reaching the receptors and the events inside the
person ?
transduction how energy in the environment gets
transformed into electrical energy by the nervous
system
information processing what happens to the
electrical signals as they travel through the
nervous system to the brain
sensory coding how the brain understands what
the electrical signals reaching it mean
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2) What is the relationship between the events
occurring inside the person and the persons
sensory experience?
3) What is the relationship between the stimuli
reaching the receptors and our sensory experience?
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Techniques for studying the steps in perception
psychophysics
physical stimulus
physiological response
sensory experience
animal single-unit recording
animal lesion studies
human clinical studies
human brain imaging magnetoencephalogra
phy positron emission tomography functional
magnetic resonance imaging event-related
potentials
human brain imaging
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Early Philosophy of Perception

• Heraclitus (540480 BCE) You can never step
  into the same river twice.
• everything is always changing
• idea that perceiver cannot perceive the same
  event in exactly the same manner each time

• We now know
• adaptation a reduction in response caused by
  prior or continuing stimulation

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Early Philosophy of Perception

• Platos The Allegory of the Cave (380 BCE)

Fig 1.3
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Early Philosophy of Perception

• We now know
• Perception and your sense of reality are the
  products of evolution
• survival
• importance of type of energy in the environment
  determines which senses have developed

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Early Philosophy of Perception

• Some species sense energies that humans cannot
• bees see ultraviolet lights
• rattlesnakes sense infrared energy
• dogs and cats can sense sounds with higher
  frequencies
• birds, turtles, and amphibians use magnetic
  fields to navigate
• elephants can hear very
• low-frequency sounds,
• which are used to
• communicate

Fig 1.5
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Early Philosophy of Perception

• Democritus (460370 BCE) the world is made up of
  atoms that collide with one another, and the
  sensations caused by these make contact with our
  sense organs
• perception is the result of the physical
  interaction between the world and our bodies
• idea of primary qualities and secondary qualities

• We now know
• sensory transducer a receptor that converts
  physical energy from the environment to neural
  activity

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Nativism and Empiricism

• nativism the idea that the mind produces ideas
  that are not derived from external sources
• we have abilities that are innate and not learned

• Descartes (15961650) dualist view of the world
  both mind and body exist separately

• mindbody dualism

Fig 1.6
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Nativism and Empiricism

• monism the idea that the mind and matter are
  formed from, or reducible to, a single ultimate
  substance or principle of being
• modern day psychologists who believe that
  consciousness can be studied scientifically take
  this approach

• materialism the idea that physical matter is the
  only reality, and everything including the mind
  can be explained in terms of matter and physical
  phenomena
• mentalism the idea that the mind is the true
  reality, and objects exist only as aspects of the
  minds awareness

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Nativism and Empiricism

• empiricism the idea that experience from the
  senses is the only source of knowledge

• Hobbes (15881678) believed that everything that
  could ever be known or even imagined had to be
  learned through the senses

Fig 1.7
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Nativism and Empiricism

• Locke (16321704) sought to explain how all
  thoughts, even complex ones, could be constructed
  from experience with a collection of sensations

Fig 1.8
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Nativism and Empiricism

• Berkeley (16851753) studied ways in which
  perception is limited by the information
  available to us through our eyes

• concluded that all of our knowledge about the
  world must come from experience, no matter how
  limited perception may be

- the world exists only to the extent that it is
perceived
Fig 1.9
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Nativism and Empiricism

• Hume (17111776) argued that the world seems very
  real because perception is highly reliable as
  long as the world is stable, our senses deliver
  the same answers every time

- illusions are instances in which perception is
reliable but not accurate
Fig 1.10