Acquisition of the same/different concept
by an African grey parrot: learning with
respect to categories of color, shape,
and material
DR. IRENE PEPPERBERG(PARROT LEARNING)-CORE
STUDY 3
Background

Psychologists believe only human possess true
language skills alongside the ability to show range of
cognitive skills.

One cognitive skill that had been reported as a
specific concept seen in humans is the
comprehension of “same” or “different”

Psychologist Premack research on pigeons showed
that pigeons may understand “same” but not
”different” but no other research had attempted to
investigate this cognitive skill.
Cont. . .

Identifying items as the same or different requires a
particular set of cognitive skills. Firstly, the animal
must recognize the category being shared(for
example, that both in green color). From this single
attribute they must also realize that this sameness
can be applied to other novel items.

This requires a skill known as symbolic representation,
meaning the concept of same and different
learned from one experience can be applied to an
entirely new and different situation.
Cont. . .

Previous research had only asked non-humans to state
same or different without category label, or just
indicate whether the object is same or different, simply
press a lever to indicate whether same or different and
recognize pairs that were 100% same or different.

Pepperberg reported that Alex, an African grey parrot
can categories objects(color, shape, material), count
up to six and use functional phrases

This study was designed to test the cognitive skills of
same/different comprehension in African grey parrot.

Part of the process involved in the study used social
learning process & operant conditioning
Aims
1.
The aim is to replicate the findings of linguistic and
cognitive skills that had been previously achieved
with chimps in a grey parrot.
2.
To investigate if an avian object could use vocal
label to demonstrate symbolic comprehension of
the concepts of same and different.
Methodology





Research Method: Experimental Case Study
Sampling technique & Participants: opportunity
sampling –an African grey parrot
Data Collection: Quantitative
Data Analysis: Measure of central tendency-Mean
Variables
 IV: whether the object is familiar or novel
 DV: whether the parrot responds correctly to the
questions about ”what’s same” & “what’s different”
About Alex. . .

Alex had been involved in prior research since 1977 on
communication and cognition for around 10 years. He
had a free access to all parts of the laboratory.

Alex had considerable vocabulary as a result of his
previous experience as a research subject. He could
name colors(red, green, yellow, blue & grey) several
shapes(triangle, square), different kinds of material
(wood, cork, paper) & metallic objects(key & chain)

During his sleeping hours he was placed in a cage with
water and standard seed mix, fruits, nuts, vegetables &
toys to play with.

Alex died in 2007 of natural cause at the age of 31
Design

Alex was presented with two objects that could be
differentiated based on three categories: color,
shape, material

He would then be asked either what’s same or
what’s different.

A correct response only be recorded if Alex
vocalized the appropriate category and not the
specific color, shape or material.
Cont. . .

Alex had to go through four processes to get a
correct response:
1.
Attend to multiple features of two different objects
2.
From the vocal question determine whether the
response is based on sameness or difference
3.
Work out what is same or different
4.
Vocally produce a category response
Cont. . .

Alex could understand abstract categories. He
could respond correctly to question such as “what
color” & “what Shape”

He could explain why something is same or
different.

Alex was tested on similar and novel objects that
were not in his labelling repertoire(a stock of skills
that individual habitually uses)
General Training

The primary technique used in Alex learning was called
model/rival technique based on principles of social
learning.

One of the human acts as a trainer while the second
human answered question about objects, giving praise
reward(the object itself) for correct response and
disapproval for incorrect answer. The second human
was acting as a model for alex response but also as
rival for the trainers attention. The role of model/rival &
trainer were frequently reversed and alex was given
the opportunity to participate in these sessions.

To keep alex motivation high he would be rewarded
with item of his choice
Training( same/different)

A trainer would hold up two objects in front of the
model/rival & simply ask what’s same or what’s
different then the roles were reversed.

Both types of question and the training objects were
mixed within each session of training. The initial training
contrasted just the categories of color, shape, matter.

Sessions occurred two to four times per week and
lasted from five min to one hour.

To prevent boredom alex was also trained on number
concept, new labels for other objects, recognition of
photographs and object permanence.
Experimental Procedure

After training trials were carried out by secondary
trainers who had never trained alex on same or
different labelling. This was used to reduce any
effect of cuing from the original
trainer(Pepperberg).

On a previous day the principal trainer would list all
possible objects that could be used for testing. A
student who was not involved in any training of Alex
would then choose from the same or different pairs
and then randomly order the questions. A
secondary trainer would present alex with the
object and then ask a question what’s same or
what’s different.
Cont. . .

The principal trainer was present during the times of
the trial with her back to alex. she never knew what
was being presented to alex. However, she would
repeat out loud what she thought alex had said.

If alex gave a correct response he was
rewarded(operant conditioning/positive
reinforcement) if not then the same object was
presented again with the same question asked until
the correct response was given. The same materials
were never presented again during the test so there
was a single first trial response.
Cont. . .

To prevent boredom and expectation cuing a
range of different question, similar pairings of familiar
objects used in training and novel object pairings
were presented to alex during trials.

Alex was never tested exclusively on same or
different in one session and was never tested
successively in one session with the same question

Testing took place over 26 months

The training for alex to acquire color and shape
labels took four months and matter took nine
months.
Cont. . .

Objects and pairing used for experimental trials
were both similar to training process and novel. Any
completely new objects was within alex’s
environment for several days prior to being used so
that alex got used to at least seeing the object to
reduce any fear response he may show.

Pepperberg also used probes in testing phase. Alex
was asked questions where the correct category
label could be two of the three labels. E.g. he may
have been shown a green wooden triangle and a
yellow wooden trainable and asked what’s same?
Data Calculation & Results

Percentage success rate on trials was measured for
familiar and novel objects by dividing the number of
correct identification by the total number of
presentations(Mean)
1.
Familiar Objects: Alex scored 78%correct
responses overall and 70% on first trial only
performance
2.
Novel Objects: Alex scored 85%correct responses
overall and 82% on first trials.
3.
Probes: Alex scored 90% correct responses overall
and 89% on first trials.
Conclusion

The data indicates that avian subject can show
symbolic comprehension of the concept of
same/different. His scores on tests were above
chance suggesting he understood what the
questions were asking. This was shown via the probe
questioning.

It would therefore appear that symbolic
representation in the case of same and different is
not exclusive to primates
Evaluation- Strengths
1.
The research involved collecting quantitative data in
the form of correct responses to the same/different
questions.
2.
Ethical guidelines followed: Number, housing,
procedure, rewards, protection from distress
3.
Advantages of using animal: relatively easy and
cheap to care for. Alex had been involved in
training for other studies and was known to respond
well to training in vocabulary exercise. The study
was conducted over a number of years which
would have been difficult to achieve with human
participant.
Cont. . .

Lab experiments have high levels of standardization and so
can be replicated to test for reliability. the study had
strandardized materials & tests. The trials were recorded so
they can be rechecked for accuracy

Case study: detailed in depth information regarding cognitive
abilities of the parrot. Led to new discovery that animals also
have the ability of symbolic comprehension.

Lab experiments have high levels of control that result in high
internal validity such as using secondary trainer during trials,
testing Alex on novel objects and on probes, using video
recording for trials, testing was delayed for the purpose of
accuracy because alex had not learned to say matter(he
pronounced mah mah). This shows that it was IV effecting DV.
Alex knew what he was talking about, his response was not
due to practice effect or rote learning and researcher bias
was also eleminated.
Weaknesses
1.
Lab experiment so low ecological validity and tasks
lack mundane realism.(external validity)
2.
Only alex was used in the study so this could make
generalizability difficult(population Validity). Alex can
be different from other African grey parrots. If this is the
case, Alex may be unique and have skills that do not
represent a wider population of African grey parrots.
3.
Unethical because caging a bird and keeping it in an
artificial environment and engaging it in artificial tasks.
4.
Practical imitations to working with animals. The parrot
is unable to explain its reasoning which can cause
interpretation bias.
Nature Vs Nurture
Nature

-
Nurture

Theories of operant
conditioning and social
learning demonstrate Alex
nurture based learning.
Application to everyday life

Using techniques of operant
conditioning(reinforcement) and social
learning(modelling) animals could be trained

** read book for detailed evaluation
Exam Style Questions
1.
Discuss two strengths and two weaknesses of
Pepperberg (parrot learning) study. One of the points
should include use of animals in research. (10)
2.
Alex’s primary trainer was present in each trial.
However, they did not look at the parrot and were
asked to repeat his response. Explain why Pepperberg
was given this role.(4)
3.
How was dependent variable operationalized in
Pepperberg study.(2)
4.
Describe one way that nurture is illustrated in
Pepperberg’s study.(4)
5.
Describe the techniques used in Alex training. (4)