•
• The first sample on the right is the “Ouchi Illusion” (Ouchi 1977,
Spillmann et al 1986). When you shake you head rapidly, or better
shake the display, a central disk will segregate as a distinct object,
which in addition can seen to be floating atop the background.
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Akiyoshi Kitaoka’s image on the left is called “Out of Focus”. It also leads
to a seeming shift of the central disk with respect to the surround. It is
very effectively provoked by the eye movements occurring during
reading. So, while you are reading this cast your “inner eye” below and
watch for a seeming decoupling of disk and background. You may also
observe that the disk floats above the background.
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• This sample is called “Floating Motion” from Pinna & Spillmann
(2002). You do not need to shake your head, or use saccades from
reading. Rather, just by exploratory eye movements over the image,
the center square “decouples”. Here the background seems to move,
while the central square remains in place, and seems to float on top.
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• As Kitaoka & Ashida (2003) describe, asymmetric
luminance steps are required for this to work. Presumably
appearance of these triggers motion detectors.
• Gregory & Heard (1983) were the first to describe that
asymmetric luminance steps cause illusory movement.
Sensory Memory
• George Sperling was one of the first
researchers to demonstrate iconic memory
in 1960.
• Those before him used the whole-report
technique to measure the capacity of iconic
memory.
– In the experiment, subjects are presented with a
matrix of letters for just merely 50 milliseconds
– After the image disappears, subjects are asked
to recall all of what they saw
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The Capacity of Iconic Memory
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• With this type of procedure, most people
would be able to remember four or five
letters
• But you know that you were shown more
than just four or five letters, so the true
capacity of iconic memory must be greater
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Partial Report Technique
Partial Report Technique
(Sperling, 1960)
• Allowed researchers to measure sensory memory
(specifically iconic)…without disrupting rapidly
decaying contents
– Sperling felt that the limitations of our span of
apprehension were less likely due to visual factors and
more likely attributed to the apparently restrictive
nature of our information processing architecture, (i.e.,
our inability to remember and report more than a few
items at a time).
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• Using special equipment, Sperling designed the
partial-report technique in which subjects are
only asked to report a specific part of the display
• Immediately after the display disappears, a tone
sounds
– High tone-subject report the top row
– Low tone-the bottom row
– Middle tone-the middle row
• The subject does not know ahead of time which
tone will be sounded.
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Using this method, the subjects seemed to store between
nine and ten items in iconic memory.
Partial Report Technique
(Sperling, 1960)
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Memory
• Acquisition, Storage, Retrieval
– We must have a way to add new information
– The vast amounts of information that we
acquire over our lifetimes must be stored
– Information is not much good to you unless you
can retrieve it
• Start with analysis of memory acquisition
– Note that ultimately, the three components are
interdependent and interactive
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Memory as Information-processing
The Route into Memory
• How do we acquire new information?
Incoming
– By what methods do we study this issue?
Information
Sensory
Analysis
• Information processing approach
– Box and arrow models representing stages and
processes
Stage
One
Input
Stage
Two
Stage
Three
Output
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A series of stages
through which
information is
detected,
recognized, stored,
and retrieved
Short-term
(working)
memory
Long-term
(secondary)
memory
Maintenance
via rehearsal
Loss?
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Are there two types of memory?
Learning Lists of Items
• Short-term (working) memory
– Small, at hand, in use, active, current, fast
• List of 30 words, one per second, followed
by free recall of as many words as can be
remembered
• Serial position curve
• Operator tells you a phone number and you dial it
• Long-term (secondary) memory
– Vast, reference library, files, dormant, slow
• Recall your third grade teacher’s name
• What is the evidence for the distinction and is it
persuasive?
– Primacy effect
– Does it imply two systems that are distinct in the
brain?
– Recency effect
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• Memory rehearsal, more attention
• Still in working memory so easily accessible
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