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Practice task An examiner presents the stimuli one by one and asks a subject to judge whether there is a face or not on

each stimulus.

INSTRUCTIONS

I'm going to show you some black and white random patterns. In a subset of them, human faces

are superimposed. When you find a face, please say “Yes” and tell me the place where you see a

face. When you don't see a face, please just say “No”.

(Presentation of the first stimulus)

“Do you see a face or not?”

When subject's response is “Yes”, the examiner should say “That’s right” or "Correct" and

moves on to the next picture. If subject's response is “No”, the examiner should point to the face

and say “There is a face here, so the correct answer is 'Yes' ". When a subject does not appear to

understand the task, the examiner should repeat the instructions until the participant has a full

understanding.

(Presentation of the second stimulus)

“Is there a face, or not?”

If a subject responds with “No”, the examiner should say “That’s right” or "Correct" and move

on to the next picture. If subject's response is “Yes”, the examiner should say “There is no face.

The correct answer is "No".” Again, when a subject does not appear to understand the task, the

examiner should repeat the instructions.

(The presentation of the third stimulus)

Same as above.

Important notes

The aim of the practice task is to make sure that a subject understands that there are two types of

stimuli: those with a face and those without a face.

If a subject asks whether the stimuli have human faces or ones of animals, an examiner should reply that

“It doesn't matter. Either is OK".

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Noise task (40 sheets) Examiner presents stimuli one by one. The duration of presentation for each stimulus is up to 30 seconds.

The subject is required to figure out whether there is a face or not on each stimulus. An examiner may move

on to the next stimulus when a subject makes a clear response before the 30 second time limit. (Note:

This is different from the scenery task in which an examiner has to give a subject enough time to make

descriptions as detailed as possible.)

INSTRUCTIONS

"Now, let's start the test"

(First stimulus presentation)

“Is there a face, or not?”

(Subject’s response)

“Good.”

(Recording the subject's response on the recording sheets and moving on to the next stimulus)

“Is there a face, or not?”

Repeat the same procedures for the remaining stimuli.

Important notes

If a subject seems to try to find faces in all stimuli and not to understand that there are both stimuli

with a face and those without, an examiner should give an instruction of “There are stimuli without

a face as well as those with one”.

If a subject responds just with “I don’t know”, the examiner should encourage him or her with

comments of “If you see a face, please say 'Yes'. If you find no face, say 'No'.”.

When a subject responses with such comments as “It looks like a face", the examiner has to make clear

whether the subject regards it an illusion or real one.

Do not give any feedback to subjects on whether their answer is correct or not.

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Scoring Subject’s responses are classified into the following three categories.

1. CORRECT:

(a) When a subject responds with “Yes” on the stimuli with a face and;

(b) When a subject responds with “No” on the stimuli without a face.

2. PAREIDOLIA:

(a) When a subject responds with “Yes” on the stimuli without a face and;

(b) When a subject responds with “Yes” on the stimuli with a face but with pointing to locations at

which no face exists.

3. MISS:

(a) When a subject answers “No” on the stimuli with a face.

Recording

The recording of responses should be done according to the following procedures:

1. CORRECT:

Circle “N (null)” or “face” in the left column of the record paper.

2. PAREIDOLIA:

Write “P” in the middle column of the record paper.

3. MISS:

Cross (X) on the "Face" in the left column of the record paper.

Important notes When a subject fails to find a face at the correct locations and instead identifies non-existent faces at locations

at which no faces exists, the response should be categorized into both MISS and PAREIDOLIA. Therefore,

the sum of the numbers of CORRECT, PARIEIDOLIA and MISS responses can be more than 40.

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Example of the recording of the record paper

Record the total numbers of correct responses, pareidolias and misses.

Pareidolia task2012082120120821

Practice

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