Running head: HEADER TEXT/SHORTENED TITLE, e.g. Face Inversion
Title of Your Lab Report, e.g. ‘The effect of inversion on the identification of familiar faces’
by
Catherine Chauder
200901948
&
Liam Walsh
200704453
A laboratory report
presented to R. McInnis
in Psychology 225
Sensation and Perception
Department of Psychology
St. Francis Xavier University
November, 29, 2012
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Running head: HEADER TEXT/SHORTENED TITLE, e.g. Face Inversion
Abstract
The purpose of the present study was to investigate how [SOME INDEPENDENT VARIABLE
(S)] affect [SOME DEPENDENT VARIABLE(S)]. This was done ...
It was predicted that…. As expected, …. We conclude that …
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Running head: HEADER TEXT/SHORTENED TITLE, e.g. Face Inversion
Title of your study
Face perception is an important process through which the brain and mind can understand
and interpret human faces. The process is essential for recognizing familiar faces, interpreting
human expressions which outwardly display emotions, and basic social interaction. Facial
expressions are used as a silent language, communicating our current thoughts or feelings with
those around us. Our study, however, focuses on face identification pulling from memory cues as
soon as our eyes scan familiar features. It’s easy to recognize a familiar face, but sometimes it’s
hard to remember under which circumstances you know the face or in the case of our study,
match it with a name. Our study focuses not simply on facial recognition, but facial
identification. For the most part, humans are experts at upright facial recognition, but inverted
faces are significantly harder. When it comes to face identification face orientation is everything.
The aim of our experimental study is to identify the effects face orientation and order of
face stimuli have on the participants’ accuracy, as well as their reaction time. Specifically, will
investigate how the inverted face effect will vary the accuracy and reaction time in comparison
to the accuracy and reaction time of identifying upright faces. We will also investigate how the
order of face stimuli presented (upright first or inverted first) will affect the reaction time and
accuracy of face identification by comparing results between participants of each order (A or B).
In order to fully understand the face-inversion effect and how it affects our ability to identify
faces, we must explore the notion that there is a process of facial scanning that takes place during
the course of face recognition.
Peter Hills of Anglia Ruskin University, and David Ross and Michael Lewis of Cardiff
University (2011) believe that there is a hierarchy of facial features in terms of saliency for face
recognition. They state that when upper facial features (such as the eyes) are concealed, face
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Running head: HEADER TEXT/SHORTENED TITLE, e.g. Face Inversion
recognition is more heavily affected than if lower facial features are concealed. According to
their study the scanning of eyes is critical in face recognition and when the eyes are the first
fixed focal point the inversion effect may be smaller (Hills, Ross, Cardiff, 2011). However, Hills
and his colleagues (2011) continue to say that there is evidence that supports the conclusion that
eyes are typically less scanned in an inverted face and that the scanning performance follows a
more random pattern for inverted faces. Through 3 separate experiments they tested the effects
of cueing (eyes, mouth, or no cueing at all) on facial recognition. They expected and
hypothesized that eye cueing during facial inversion would implement a higher accuracy of
facial recognition than no cueing, and that cueing the mouth in both upright and inverted faces
would implement a lower accuracy than no cueing at all. The results of their experiments
demonstrated that the diagnostic utility of eyes in face perception and the location of the first
focal point have an effect on the accuracy of facial recognition, which could potentially underpin
the face-inversion effect (Hills et al, 2011).
In our experiment it is impossible to tell how participants implemented cueing, if at all.
Therefore, since Hills and his colleagues (2011) stated that the scanning performance follows a
random sequence during inverted facial recognition (Hills et al, 2011), we can assume that the
majority of the participants in our study cued the mouth during scanning, or did not cue any focal
point at all. This means that if our participants cued the eyes during inverted facial scanning,
would we expect our mean accuracy of participants to be much higher.
Galit Yovel and colleagues (Yovel et al, 2012) set out to find if there were a difference in
orientation between different race-faces and same-race faces in the perception of neonatology
nurses. They found that poor different race-face recognition is usually credited to little
experience of the visual system with different race-faces. Recognition of passive exposure to
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Running head: HEADER TEXT/SHORTENED TITLE, e.g. Face Inversion
same race-faces is often represented by attempts to individuate same race-faces at a sub
categorical level. They conducted two experiments. First they had participants view three sets of
six face photos. Of the six photos were three infants and three adults. Presented in random order
the identification of adult faces score was higher. In the next phase each of the identified faces
was contrasted with five distractor faces. The participants were asked to identify one of the six
faces. Massive exposure to different race-faces in participant neonatology nurses shows better
ability to individuate faces from a control group of same-race adult faces than that of infant
faces. Despite seeing massive amounts of different-race faces over years neonatology nurses
more readily identified same race-faces consistent with the hypotheses quality of faces is more
salient in face recognition in the visual system than passive but massive exposure to different
race-faces.
A 2x2 mixed design (within and between subjects) was employed in which the two
independent variables were: face orientation (upright or inverted) and order (A – upright
presented first, or B – inverted presented first). The 56 participants of the study were paired up
into groups and assigned an order in terms of face stimuli. By doing this both levels of upright
and inverted face orientation were shown to each participant of each group. The participants
assigned A would view the upright face stimuli first, and the participants assigned B would view
the inverted face stimuli first. Since conditions were assigned, a measure of control was
established in the form of counterbalancing to ensure consistency across situations. The face
stimuli were counterbalanced as each face appeared upright or inverted in a different but equal
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Running head: HEADER TEXT/SHORTENED TITLE, e.g. Face Inversion
order across all groups. Participants were shown the face stimuli on a computer screen controlled
by their partners (playing the roles of the experimenter) whom used a keyboard. Participants
were timed on the length of their reaction to face stimuli and were required to write their
response on a sheet of paper. Assigning an order to each participant is important for contrasting
results between both groups. After the experiment we should be able to verify the advantages or
effects that each order has on reaction time and accuracy. Face orientation plays a very important
role in face identification, and our study intends to emphasize our ability to recognize faces when
they are presented to us as altered or unaltered entities.
It is expected and hypothesized that participants will have a slower reaction time to
stimuli caused by the inverted faces, and that participant accuracy will also be affected by the
inversion effect causing the percentage correct to be lower. In short, face orientation
(independent variable 1) and order (independent variable 2) will have a heavy effect on
participant reaction time and participant accuracy. To address whether these potential effects will
occur an experiment with 56 participants was conducted aiming to test these hypotheses.
Method
Participants
Participants were 56 students from a sensation and perception psychology class at Saint
Francis Xavier University, who participated as part of their lab requirement.
Apparatus
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Running head: HEADER TEXT/SHORTENED TITLE, e.g. Face Inversion
Participants used a computer during the study. The computer presented stimuli comprised
of 18 celebrity faces in total (9 were presented normally and 9 were presented in an inverted
form). The partner (experimenter) of the participant used the keyboard to change the stimulus
when the participant indicated that they were ready for a new stimulus to be presented. A printed
Participant Response Sheet was used by the participant to write and record their answers. Finally,
a time keeping instrument was used by the experimenter (instrument varied per group; phone,
stop watch, wrist watch etc.) to record the reaction time of the participant in seconds.
Procedure
The experiment required the 56 participants to formulate and work in pairs (the odd
number of students was compensated by the instructor pairing up with a student). Each
participant was assigned a letter within their group (A or B) and sat in front of one computer with
a slideshow presented on the computer screen. The slide show consisted of 18 celebrity face (the
stimuli of the experiment); 9 were presented normally and 9 were presented in an inverted form.
The subject to undergo the experiment first was decided amongst the pair, leading the partner to
take on the role of experimenter.
Two experiments occurred per group, ensuring that each participant played the role of
both the subject and the experimenter. During the experiment the participant was presented with
18 celebrity faces in a different order which depended on their assigned letter. Order A presented
9 faces in a non-inverted manner, followed by 9 faces in an inverted manner. Order B presented
9 faces in an inverted manner, followed by 9 faces in a non-inverted manner. However, for both
orders the organization of celebrity faces stayed the same; meaning the faces in Face
Identification Part 1 and Part 2 were identically organized for both Participant A and B, but they
were presented in the opposite orientation. The participant to go first was presented with the first
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Running head: HEADER TEXT/SHORTENED TITLE, e.g. Face Inversion
9 faces and they recorded their written answer on the printed Participant Response Sheet. While
this was happening, the experimenter changed the stimulus by using the keyboard when the
subject indicated they were finished recording their response. The experimenter timed the subject
using a time keeping device and recorded their reaction time in seconds once the subject had
completed the first portion of the experiment. When both the subject and experimenter were
ready, 9 more faces were presented in the opposite orientation and the recording proceeded.
After experiment 1 was finished, the participants reversed roles and conducted experiment 2.
Finally, after both experiments were conducted the participants recorded how many facial
recognitions they had recorded successfully and how many faces they recognized as familiar.
Participants were given 75 minutes to set up and complete the experiment.
Results
From the data collected it can be seen that for Upright Face Orientation, Group A
(participants who viewed upright first) on average obtained a mean accuracy score of 77.3,
whereas Group B (participants who viewed inverted first) on average obtained a mean accuracy
score of 61.6. For Inverted Face Orientation, Group A on average obtained a mean accuracy
score of 38.9, whereas Group B on average obtained a mean accuracy score of 59.6. In terms of
Latency for Upright Face Orientation, Group A on average obtained a mean reaction time of 47.3
seconds, whereas Group B on average obtained a mean reaction time of 49.1 seconds. For
Inverted Face Orientation, Group A on average obtained a mean reaction time of 61.2 seconds,
whereas Group B on average obtained a mean reaction time of 50.3 seconds.
In Figure A & B the effect of Face Orientation (independent variable X) and Order
(independent variable Y) on the dependent variables are shown. It can be noted that Face
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Running head: HEADER TEXT/SHORTENED TITLE, e.g. Face Inversion
Orientation is a within-subject variable and Order is a between subject variable. Figure A.
demonstrates the effect of Face Orientation and Order on the accuracy (percentage correct) of the
participants. Each darkened bar represents the average of 28 participants (Group A) for upright
and inverted face orientation, while each lightened bar represents the average of 28 participants
(Group B) for upright and inverted face orientation. A trend in the data shows that those who
were exposed to upright stimuli first (Order A) had a higher accuracy value for upright faces than
those who were exposed to inverted stimuli first (Order B). Furthermore, those who were
exposed to inverted stimuli first (Order B) had a higher accuracy value for inverted faces than
those who were exposed to upright stimuli first (Order A). Another trend in the data shows that
the average accuracy for both Group A & B was higher for upright face orientation than inverted
face orientation.
Figure B. demonstrates the effect of Face Orientation and Order on the reaction time (in
seconds) of the participants. Again, each darkened bar represents the average of 28 participants
(Group A) for upright and inverted face orientation, while each lightened bar represents the
average of 28 participants (Group B) for upright and inverted face orientation. A trend in the data
shows that order had the same effect on accuracy that it did on reaction time. Another trend in
the data shows that the average reaction time for both Group A & B was higher for upright face
orientation than inverted face orientation
Discussion
The results of the current study …
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Running head: HEADER TEXT/SHORTENED TITLE, e.g. Face Inversion
The present study lends support to the ideas proposed by …
It is possible that the present study is limited by …
Future research would benefit from…
There are some broader implications of the currents study with regards to
….……………. ……………. ……………. …………….
The experiment that was conducted reports results that demonstrate the face-inversion
effect and its influence on reaction time and accuracy of face identification. The experiment
established primarily that inverted face stimuli were harder to identify and the process of
recognizing the inverted face had a longer duration. Specifically, when compared to upright face
identification, inverted face stimuli were identified less accurately and reaction time to the
inverted face stimuli was much longer than that of the reaction time to the upright face stimuli.
These findings support our first hypothesis suggesting that face orientation, specifically the faceinversion effect would have a negative influence on our dependent variables, reaction time and
accuracy. Furthermore, it was discovered that in terms of order, whichever face orientation
stimuli (whether it be upright or inverted) was presented to the participant first, on average had
an advantage on their face identification results. In other words, participants who were first
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Running head: HEADER TEXT/SHORTENED TITLE, e.g. Face Inversion
exposed to inverted faces, on average, tended to do better on inverted face stimuli identification,
in terms of both accuracy and reaction time, than their partner. The same can be said for the
opposite face orientation; participants who were first exposed to upright faces, on average,
tended to do better on upright face identification, in terms of both accuracy and reaction time,
than their partner.
It is easy to understand why upright face stimuli were identified more easily and faster,
but it was unexpected that the order of face stimuli would have such a drastic effect. One
explanation can be related back to Hills and his colleague’s (2011) study on feature diagnosticity
in the face-inversion effect. In their study, the emphasized over and over again the importance of
cueing in face recognition, and that the process for upright face recognition and inverted face
recognition differed. Inverted face recognition process tended to be more random, without
cueing, while the upright face recognition process tended to take cues from the eyes and the
mouth (Hills et al, 2011). Perhaps the first exposure to face orientation set the tone for cue
patterns in each participant. For example, the cue patterns Participant A developed from the first
portion of the experiment (in their case upright face stimuli first), may have carried over to the
second portion of the experiment and were implemented in identifying inverted face stimuli. This
resistance to changing the scanning process during facial recognition could have negative effects
on both the accuracy and reaction time of the participant.
It is possible that the present study is limited by the methodology of the experiment. Due
to the condition that all the participants were located in the same room it was easier for them to
hear the verbal answers of the other participants. The participant to undergo the experiment
second within their group was also at an advantage. Since the second participant had been
previously exposed to the face stimuli during the first participant’s trial, they could rely more
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Running head: HEADER TEXT/SHORTENED TITLE, e.g. Face Inversion
heavily on their memory to make an accurate guess as opposed to solely relying on their ability
to recognize the face stimuli.
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Running head: HEADER TEXT/SHORTENED TITLE, e.g. Face Inversion
References
Hills, P. J., Ross, D. A., & Lewis, M. B. (2011). Attention misplaced: The role of diagnostic
features in the face-inversion effect. Journal Of Experimental Psychology: Human
Perception And Performance, 37(5), 1396-1406. doi:10.1037/a0024247
Yovel, G., Halsband, K., Pelleg, M., Farkash, N., Gal, B., & Goshen-Gottstein, Y. (2012). Can
massive but passive exposure to faces contribute to face recognition abilities?. Journal Of
Experimental Psychology: Human Perception And Performance, 38(2), 285-289.
doi:10.1037/a0027077
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Running head: HEADER TEXT/SHORTENED TITLE, e.g. Face Inversion
a) Accuracy of Face Identification
Percent Correct Identification
100.0
Upright first
Inverted first
75.0
50.0
25.0
0.0
Upright
Inverted
Face Orientation
b) Latency of Face Identification
75.0
Reaction Time (seconds)
Upright first
Inverted first
60.0
45.0
30.0
Upright
Inverted
Face Orientation
Figure A. Accuracy of Face Identification
Figure B. Latency of Face Identification
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Running head: HEADER TEXT/SHORTENED TITLE, e.g. Face Inversion
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