PSY 219 – Academic Writing in Psychology
Inst. Nilay Avcı
A LAB REPORT EXAMPLE
(A Brief Illustration of the Research Report Genre)
Cognition: Numerical memory span in a chimpanzee
NOBUYUKIKAWAI AND TETSUROMATSUZAWA
Primate Research Institute, Kyoto University, Inuyama, Aichi 484-8506, Japan
(Introduction)
A female chimpanzee called Ai has learned to use Arabic numerals to represent
numbers 1. She can count from zero to nine items, which she demonstrates by
touching the appropriate number on a touch-sensitive monitor 2, 3, and she can order
the numbers from zero to nine in sequence 4-6. Here we investigate Ai's memory
span by testing her skill in these numerical tasks, and find that she can remember
the correct sequence of any five numbers selected from the range zero to nine.
Humans can easily memorize strings of codes such as phone numbers and
postcodes if they consist of up to seven items, but above this number they find it
much harder. This 'magic number 7' effect, as it is known in human information
processing7, represents a limit for the number of items that can be handled
simultaneously by the brain.
(Method)
To determine the equivalent 'magic number' in a chimpanzee, we presented
our subject with a set of numbers on a screen, say 1, 3, 4, 6 and 9. She had already
displayed close to perfect accuracy when required to choose numerals in ascending
order, but for this experiment all the remaining numbers were masked by white
squares once she had selected the first number. This meant that, in order to be
correct in a trial, she had to memorize all the numbers, as well as their respective
positions, before making the first response. Chance levels with three, four and five
items were 50, 13 and 6%, respectively.
(Results)
Ai scored more than 90% with four items and about 65% with five items,
significantly above chance in each case. In normal background trials, response
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PSY 219 – Academic Writing in Psychology
latency was longest for the first numeral and much shorter for all the others,
indicating that Ai inspected the numbers and their locations and planned her actions
before making her first choice. In masking trials, response latency increased only
for the choice directly after the onset of masking, but this latency was similar to
those recorded in background trials, indicating that successful performance did not
depend on spending more time memorizing the numbers.
In one testing session, after Ai had chosen the correct number and all the
remaining items were masked by white squares, a fight broke out among a group of
chimpanzees outside the room, accompanied by loud screaming. Ai abandoned her
task and paid attention to the fight for about 20 seconds, after which she returned to
the screen and completed the trial without error.
(Discussion)
Ai's performance shows that chimpanzees can remember the sequence of at
least five numbers, the same as (or even more than) preschool children. Our study
and others8-10 demonstrate the rudimentary form of numerical competence in nonhuman primates.
References
1.
Matsuzawa, T. Nature 315 , 57-59 (1985). Links
2.
Matsuzawa, T., Itakura, S. & Tomonaga, M. in Primatology Today (eds Ehara, A., Kumura,
T., Takenaka, O. & Iwamoto, M.) 317-320 (Elsevier, Amsterdam, 1991).
3.
Murofushi, K. Jpn. Psychol. Res. 39 , 140-153 (1997).
4.
Tomonaga, M., Matsuzawa, T. & Itakura, S. Primate Res. 9, 67-77 (1993).
5.
Biro, D. & Matsuzawa, T. J. Comp. Psychol. 113 , 178-185 (1999).
6.
Tomonaga, M. & Matsuzawa, T. Anim. Cogn. (in the press).
7.
Miller, G. A. Psychol. Rev. 63 , 81-97 (1956).
8.
Rumbaugh, D., Savage-Rumbaugh, E. S. & Hegel, M. J. Exp. Psychol. Anim. Behav.
Process. 13 , 107-115 (1987). Links
9.
Brannon, E. & Terrace, H. Science 282 , 746-749 (1998). Links
10.
Boysen, S., Mukobi, K. & Berntson, G. Anim. Learn. Behav. 27 , 229-235 (1999).
Copyright Nature Volume 403 Number 6765 Page 39 - 40 (2000) . Dowloaded from the web March 31,
2000 (http://www.nature.com)
http://www.uic.edu/classes/psych/psych303/Psych303/Tbl2.html
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PSY 219 – Academic Writing in Psychology
Table 3. JRV of Nature article (appeared in Tennessean, January 6, 2000)
Sentences in JRV
Sections in News Storya
From Memory, Chimp gets numbers Right
Headline
A chimpanzee has shown it can
Main Event
remember the correct sequence of five
random numbers — an experiment that adds
to the growing evidence that animals have
some basic numerical ability. A female
chimp tested with the numbers between zero
and nine performed about as well as an
Rhetorical Moveb
Move 1 and
2: Hooking the reader
and highlighting the
major research
outcome
average preschool child would, researchers
at Kyoto University in Japan have found.
The Chimp, named Ai, had already
Background
demonstrated that she could put five
numbers in ascending order when they were
scattered across a computer screen.
Move 3: Reviewing
related reseach.
But Kyoto researchers Nobuyuki Kawai Details of main event
and Tetsuro Matsuzawa reported in today’s
issue of the journal Nature that they took the
experiment a step further.
Move 4: Purpose of
the new research
When the chimp touched the first
Details of main event
number, the four others were covered up
behind small white squares on the
screen. She then had to touch the squares in
the proper order. Kawai and Matsuzawa
said the chimp had to memorize all the
numbers to make the right choice.
Move 7: Describing
the experimental
procedure.
The chimp succeeded better than 90% of Details of main event
the time in identifying four numbers in the
proper order, and was successful about 65%
Move 5: Identification
of positive results.
of the time with five items, far better than
chance in each case. Matsuzawa noted that
in one testing session, Ai was distracted by a
fight among chimps outside the lab, but
returned to the screen and completed the
trial correctly.
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PSY 219 – Academic Writing in Psychology
The study builds on research by Herbert
Background
Terrace and Elizabeth Brannon at Columbia
University in New York. Brannon said,
however, the Japanese research showed
stronger evidence of mathematical skill.
Move 8: Explaining
the research outcome.
“What is interesting about this work is that Consequence
they actually trained the chimpanzee to see
the relationship between the symbol and the
underlying number.”
Move 9: Stating the
implication of the
research.
a These are the categories identified by Van Dijk (1986). He segmented the news report into two major sections,
the Summary and the News story. The Summary consists of the Headline and the Lead; the News story consists
of several categories, including main event, details of main event, background, consequences, and comments.
bRhetorical moves are taken from Nwogu (1991).
http://www.uic.edu/classes/psych/psych303/Psych303/Tbl3.html
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