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Determinants of face recognition: the role of target prevalence and similarity

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Studies of facial identity processing typically assess perception and/or recognition, with designs differing with respect to one important aspect: Target Prevalence. That is, some include “target absent” (TA) among “target present” (TP) trials. In visual search tasks, TA trials shift an observer’s decisional criterion towards a stricter one, increasing error rates. However, decisional biases will differ inter-individually and can change intra-individually as well. From one standpoint, excluding TA trials is logical as it ensures comparable levels of expectation, or decisional bias across observers, and tasks. However, in reality, TA trials may occur, e.g. in police line-ups, where it is important to consider observers’ face recognition ability independently for TA and TP trials. To our knowledge, the effect of including TA trials has not been systematically investigated in tests of face recognition. We sought to fill this void by testing different versions of the previously established Models Memory Test that measures old/new recognition of experimentally learned facial identities. Our study aimed to answer the open question of whether — and if, how — observer expectation matters in face recognition with naturalistic stimulus variations. We discuss implications for line-up scenarios that are simulated in research settings and occur regularly in policing.
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RESEARCH ARTICLE
CORRESPONDING AUTHOR:
Meike Ramon
Applied Face Cognition Lab,
Institute of Psychology,
University of Lausanne,
Quartier UNIL-Mouline –
Bâtiment Géopolis, 1015
Lausanne, Switzerland
meike.ramon@unil.ch
KEYWORDS:
Face identity processing; Face
recognition; Target Prevalence;
Expectation/context
TO CITE THIS ARTICLE:
Boudry, L., Nador, J. D.,
& Ramon, M. (2024).
Determinants of Face
Recognition: The Role of Target
Prevalence and Similarity.
Journal of Cognition, 7(1): 27,
pp. 1–15. DOI: https://doi.
org/10.5334/joc.339
ABSTRACT
Studies of facial identity processing typically assess perception (via matching) and/
or memory (via recognition), with experimental designs differing with respect to one
important aspect: Target Prevalence. Some designs include “target absent” (TA) among
“target present” (TP) trials. In visual search tasks, TA trials shift an observer’s decisional
criterion towards a stricter one, increasing misses. However, decisional biases will differ
between individuals and across an individual’s decisions as well. In this way, excluding
TA trials ensures comparable levels of expectation and thus a more controlled decisional
bias both within and between observers by not considering correct rejections and false
alarms. However, TA trials may occur, e.g., in police line-ups, where it is important to
consider observers’ face recognition ability net of the potential biases introduced by
TA and TP trials. And, while these have been investigated in numerous other stimulus
domains, their effects have not yet been extended to face recognition. We therefore
sought to fill this void by testing different versions of the previously established Models
Memory Test, which measures old/new recognition of experimentally learned facial
identities. Our study found significant expectation effects, driven by target prevalence
that persist even given prevalence changes. This implies that face recognition – even
measured with naturalistic changes – is influenced by prior perceptual decisions.
LIONEL BOUDRY
JEFFREY D. NADOR
MEIKE RAMON
*Author affiliations can be found in the back matter of this article
Determinants of Face
Recognition: The Role of
Target Prevalence and
Similarity
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INTRODUCTION
Over the past two decades, scientific interest in face identity research has increased
dramatically. Searching the term “Face Processing” on pubmed.com yields 267 articles
published in the year 2000. Now, twenty years on, the same search returns seven times this
number. Several technological advances facilitating facial image creation and processing
have contributed to this growth, including proliferation of devices with cameras, alongside
rapid improvements in machine learning and artificial intelligence (AI) algorithms. These
developments have largely been benchmarked using instances where accurate processing of
facial identity is paramount, as in security and law enforcement settings (Ramon et al., 2019;
Ramon & Rjosk, 2022; Mayer & Ramon, 2023).
Assessing the extent of the benefits that these technological advances can provide requires
thorough knowledge of human performance as a benchmark. Therefore, psychological studies
over this same period have sought to characterize ability in face identity processing (FIP). These
lines of research include neuropsychological studies examining the effects of brain damage
(Ramon, Busigny, Gosselin & Rossion, 2016; for reviews see Rossion, 2022 a, b), fundamental
research investigating how real-life experience shapes measured FIP (for reviews see Ramon
& Gobbini, 2018; Meissner & Brigham, 2001), and individual differences among neurotypical
individuals (Fysh et al., 2022; Stacchi et al., 2020; Bobak et al., under review). A recent subset
of studies have focused on individuals with superior skills, so-called Super-Recognizers (Russell,
Duchaine & Nakayama, 2009; Ramon, 2021), to characterize the mechanism(s) underlying their
unique ability (Nador et al., 2021 a,b; 2022; Linka et al., 2022) and how to identify them (Mayer
& Ramon, 2023; Ramon & Rjosk, 2022; Ramon, 2021). Consequently, there has been a surge in
the development of FIP assessment tools, which typically measure specific subprocesses with
varied (at times suboptimal) reliability and precision (Fysh & Ramon, 2022; Bobak et al., under
review; Stacchi et al., 2020; Fysh et al., 2020).
TARGET PREVALENCE IN TESTS OF FIP AND VISUAL SEARCH
Across professional domains, FIP measures have been developed for several reasons (for
review, see Young & Ellis, 1989). For instance, a body of neuroscientific research aims to
understand FIP’s subprocesses and neural correlates (Rossion et al., 2020; Yovel, 2016) In law
enforcement, understanding FIP differences is important e.g., in the context of perpetrator
identification through testimony of witnesses or forensic professionals (Mayer & Ramon, 2023).
The motivation for studying FIP typically influences a range of methodological choices. These
can relate to performance measures considered, e.g., accuracy or response time for identity
matching (see. Fysh & Ramon, 2022; Nador et al., 2022), or experimental design. While some
studies seek to maximize ecological validity (e.g. Bate et al., 2018) by applying natural and
realistic changes to stimuli, others may artificially increase task difficulty by adding ambient
noise to their stimuli (e.g. Russell et al., 2009).
Furthermore, to approximate real-life scenarios, some studies consider the effect of Target
Prevalence (the presence of target identities among foils during/across experimental trials) on
FIP. Thus, in 1-to-many matching, or n-alternative forced-choice recognition tasks, the target
identity signal is often absent from the possible response options on a subset of trials. (Bruce et
al., 1999; Bate et al., 2018). This is thought to serve as a model for myriad real-world scenarios,
including policing and security. For example, a mug-shot line-up created by the police may
either include the depiction of a person of interest (target present), or not (target absent).
Ideally, witnesses and professionals should not only be able to recognize persons of interest
(or “targets”) when present, but also refrain from falsely identifying others in the lineup (“foils”)
as the perpetrator, whether or not the target is absent. However, to the best of our knowledge,
no such studies to date have systematically varied Target Prevalence during face recognition
tasks, leaving substantial doubt (warranted or not) in witnesses and professionals’ judgments.
This doubt arises from more domain-general work on visual search, wherein the role of Target
Prevalence is routinely studied in diverse scenarios, such as screening baggage at airport security
for weapons (Wolfe & Van Wert, 2010; Wolfe et al., 2007), or screening radiological images to
diagnose tumors (Nakashima et al., 2013). Critically, in both fields, targets are exceedingly rare.
In mammography, for example, only 3% of scans present a tumor (Gur et al., 2004). In radiology,
low Target Prevalence has been shown to induce miss rates as high as 30% for tumors after
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scan examinations (Evans et al., 2013). In airport security, baggage screeners reportedly miss
95% of weapons hidden in luggage (Fishel, Levine, & Date, 2015); some recent estimates hold
that only 10 firearms are identified per million passengers screened (Transportation Security
Administration, 2015).
Overall, researchers have shown that hit rates – the proportion of correctly identified targets
among foils – decline drastically when targets are rare (Wolfe et al., 2007). This “low prevalence
effect” is a major concern for visual search tasks in general, presumably also including FIP.
Importantly, though, this effect arises due to observers’ inherent bias towards signaling the
presence or absence of a target, such that when targets are rarer, observers are less likely to
signal their presence. It should be noted, though, that this need not necessarily imply decreased
sensitivity to targets; observers also make fewer false alarms (incorrectly identifying a foil as a
target) under such circumstances (Wolfe et al., 2007; Peltier & Becker, 2016).
EFFECTS OF TARGET PREVALENCE AND SIMILARITY ON FACE MEMORY
In practice, FIP-related tasks often – but not always – require memory of a given facial identity.
On one hand, for instance, police officers may screen CCTV footage for the presence of a
particular suspect whose photograph they have in hand. On the other, a witness may need
to identify a suspect specifically from memory. Unfortunately, false alarms in these scenarios
have serious ramifications, and eyewitness testimony is extremely prone to false alarms, to
the point that they are among the most common causes of suspect misidentifications (Wells
& Olson, 2003).
Consequently, the inclusion of Target Absent trials experimentally has become a priority (e.g.
Bate et al., 2018; Bruce et al., 1999; Matthews & Mondloch, 2018), leading researchers to
proffer many such assessments. However, no such studies have systematically varied Target
Prevalence to assess changes in hit rate, and remain prone to bias as they include Target Absent
trials.
To address this, we adapted one such assessment tool, the Models Memory Test (MMT; Bate
et al., 2018). The MMT measures recognition performance for learned face identities using
“ambient images” (Jenkins & Burton, 2011), i.e. naturally occurring variability in facial
appearance. Throughout two target recognition phases, observers are presented with triplets
of images containing two distractor and one target identity. Both phases differ in the similarity
between initially learned target images and the potential matching target stimulus. Similarity
can be high, with minor changes between the learned image of a given identity and its
matching probe, or low, i.e. entailing greater changes (see Figure 1). Additionally, the MMT
includes Target Absent trials at a constant rate of 50% of the trials throughout, and as such
cannot assess the effect of varying their prevalence on hit rates. Therefore, we extended it to
include conditions with only Target Present trials.
Practically, naturally occurring changes in facial appearance negatively impact face recognition
(Patterson & Baddeley, 1977). The MMT exploits this effect of image changes to systematically
increase Target-To-Match Similarity. That is, across the recognition phases, targets’ facial
appearance changes are initially less, and then more pronounced across Phases 1 and 2
(see Figure 1). Unfortunately, the parallel implementation of target absent trials as a second
novel feature of the original MMT is undesirable. Simply put, differences between high and
low similarity conditions could have been explained by either or both of these methodological
considerations (Target Prevalence or Similarity). And, since these factors operate in concert to
create a specific context for face recognition performance, a lack of simultaneous control over
them both limits the original MMT’s insight into face recognition memory performance. Our
inclusion of Target Present-Only conditions remedies this issue.
CLOSING THE GAP: CONTEXTUAL EFFECTS ON FACE RECOGNITION
For this study, Context comprises previously acquired experience within an ongoing situation.
Operationally, this translates to the effect that previous trials (or previous phase) have
on processing current stimuli, along with their potential consequences for future stimuli
(Zimmermann et al., 2007). In visual search tasks, context is often manipulated via priming,
through presentation of targets or foils (Kristjánsson & Campana, 2010). However, visual search
studies overlook these “implicit” contexts, wherein a given experience or percept can affect the
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following one(s). For example, an observer’s previous experience with low Target Prevalence
could bias their hit rates downwards on subsequent trials. Exploring the effect of Context in
a visual search task, Wolfe and colleagues (2007) reported that training with higher Target
Prevalence led to better subsequent performance in low and high Target Prevalence visual
search tasks.
We reasoned that performance should be facilitated by higher vs. lower similarity between
images used during learning and recognition, leading to increased hit rates. Additionally, we
hypothesized that hit rates would be reduced when including target absent trials compared
to when excluded. A higher Target Prevalence would increase recognition performance as
discussed earlier in the context of visual search more generally. Finally, we hypothesized that
contextual effects of Target Prevalence would show carry-over within observers, such that
those who were first exposed to low target prevalence would show lower hit rates in future
perceptual decisions and vice-versa.
METHODS
All research procedures were approved by the local Ethics Committee (Approval Number 473,
University of Fribourg, Switzerland) and conducted following the tenets of the Declaration of
Helsinki (Puri, Suresh, Gogtay, & Thatte, 2009).
OBSERVERS
An a priori power analysis determined that at least 14 observers would be necessary to detect
medium-sized effects at α = .05 and β = .8 given our experimental design. Invitations for remote
participation were sent out to sixty relatives of one experimenter, all of whom participated
Figure 1 Examples of
stimuli presented in the
Model Matching Test across
test phases. Images are
reproduced from Bate et
al. (2018) under a Creative
Commons Licence (http://
creativecommons.org/
licenses/by/4.0/).
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in the experiment (half female; mean age: 40±12 years), and who had normal or corrected-
to-normal vision. The observers were unaware of the study’s purposes concerning Target
Prevalence, Target-to-Match Similarity, Context and Cultural Exposure. Observers were randomly
assigned to one of three groups, and each group completed a different version of the MMT (see
Table 1). According to their own accounts, observers were exposed to South Asian (SA), Western
Caucasian (WC), or ethnically-mixed groups (SAWC) (see below).
INTER-ETHNICITY SOCIAL CONTACT QUESTIONNAIRE (IESCQ)
We assessed our observers’ contact with/exposure to different ethnicities to ensure that any
such exposure differences would be balanced across groups. To this end, we designed a novel,
self-administered Inter-Ethnicity Social Contact Questionnaire (IESCQ), which was implemented
online beforehand and took between five and ten minutes to complete.
The IESCQ contains 10 closed-ended questions soliciting self-reports of the quality and quantity
of own-ethnicity (South Asian or Caucasian; five items) and other-ethnicity (South Asian
or Caucasian; five items) exposure and contact. IESQCQ items assess exposure within their
work setting, various social/public settings, through personal knowledge, digital media, etc.
For example, Item 2 asked, “Consider your experiences with Caucasians (White people) within
the context of various social/public settings. Approximately, what percentage of the people you
regularly interact or socialize with are Caucasians?”. The IESCQ uses the same items for own-
and other-ethnicity. All observers rated their response to each item on a percentage scale from
0 to 100 in increments of 10%, 0 being no contact/exposure at all and 100 being maximal,
daily contact. Mean percentage scores were calculated for each observer for each of the two
ethnicities. Observers with low to no exposure/contact with the other ethnicity (0–30%) or high
exposure/contact with their own ethnicity (70–100%) were assigned to a mono-ethnic group,
whereas observers with relatively similar exposure/contact to both ethnicities were placed in
the multi-ethnic group.
STIMULI AND GENERAL PROCEDURE
All experimental stimuli were taken from the original MMT (Bate et al., 2018). They depict
naturalistic, full-color, adult male faces taken under different lighting conditions and from
various viewpoints. Stimuli presented in Phase 2 included additional paraphernalia (greater
changes) (e.g., addition of reading glasses, beanies, facial hair, etc.). Target face stimuli included
14 “ambient” images (Jenkins & Burton, 2011) of 6 target identities; foil face stimuli consisted
of 300 images, each displaying a different identity. Images preserved all external features of
the face including hair and ears.
Each TP trial involved presentation of three probe stimuli: one of a target identity and two
foil identities. Each TA trial involved presentation of three probes displaying foil identities.
Observers participated online (testable.org), using their personal computers’ web browser of
choice, in full-screen mode. Prior to commencing, they were asked to make sure they could
avoid distractions and to position themselves at one arm’s length distance from the screen.
Comparable on-screen stimulus size was ensured through a default calibration procure.
Table 1 Demographic
information of observers
assigned to the three
versions of the Models
Memory Test (MMT). Groups
were exposed to different
combinations of Target
Prevalence across Phases 1
and 2, which contained only
target present trials (TP), or
included target absent trials
(TA) (as in Bate et al.’s (2018)
original study). For all groups,
Phase 1 and Phase 2 were
characterized by high and low
Target-to-Match Similarity,
respectively, due to the degree
of ambient changes among
images across phases. Each
group first completed the
first, “easier”, followed by the
second, “harder” phase (with
lesser vs. greater ambient
changes). For Group 1, Phase
1 had low Target Prevalence
(TA/TP; i.e. target absent
and target present trials)
and Phase 2 had high Target
Prevalence (TP; i.e. only target
present trials). This pattern of
Target Prevalance was reversed
in Group 2, where Phase 1
had high (TP), followed by low
Target Prevalance in Phase 2.
* NB: This is the original MMT
reported by Bate et al. (2018).
TA/TP: indicates that a phase
contains both target absent
(TA) and target present (TP)
trials. TP: indicates that a phase
contains only target present
(TP) trials.
CONTEXT (PHASE1–PHASE2) CULTURAL EXPOSURE OF PARTICIPANTS ASSIGNED
TO CONTEXTS
N
(MALE/FEMALE); AGE ± SD
WESTERN
CAUCASIAN (WC)
SOUTH ASIAN
(SA)
MIXED (SAWC)
Group 1: Low-to-high Target
Prevalence (TA/TP—TP)
7 (3/4); 35 ± 6 7 (3/4); 45 ± 13 6 (4/2); 41 ± 11
Group 2: High-to-low Target
Prevalence (TP—TA/TP)
7 (3/4); 40 ± 12 6 (3/3); 43 ± 14 6 (2/4); 34 ± 9
Group 3: Low-to-low Target
Prevalence* (TA/TP—TA/TP*)
6 (4/2); 43 ± 18 7 (3/4); 39 ± 12 7 (5/2); 39 ± 11
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PROCEDURES & DIFFERENT VERSIONS OF THE MMT USED
The original MMT’s design was delivered to Group 3, where an initial Target Learning (encoding
and target test) was followed by two Recognition Phases of 45 trials each with low Target
Prevalence (equal proportion of TP and TA trials in each Recognition Phase). Recognition phases
differed in terms of Target-To-Match Similarity (i.e., similarity between the learned targets and
probes presented during recognition phases). As demonstrated in Figure 1, Phases 1 and 2
involved lesser vs. greater changes (change of lighting or viewpoint, vs. change of hairstyle,
addition of a beard, glasses, etc), respectively.
To assess the effect of target-absent trials on face recognition, we created two modified versions
(Group 1, Group 2; see Table 1) of the original MMT (Bate et al., 2018). At base, all versions
contain two phases schematically represented in Figure 2: (1) Target Learning (consistent across
versions) and (2) Target Recognition (differing across test versions). Target Recognition consists
of two phases (45 trials each), which differ in terms of Target-to-Match Similarity. Similarity
between learned targets and to-be-matched probes is higher in Target Recognition Phase 1
(“easy” trials), compared to Target Recognition Phase 2 (“difficult” trials), where paraphernalia
and external facial information differ between target and probe images. Target-To-Match
Similarity differed in the same manner across phases for all groups as described above.
Stimulus aspects aside, the three MMT versions differ in terms of Target Prevalence across trials,
with fixed order of Target-to-Match Similarity (low, followed by high). In the original MMT, both
Target Recognition Phases include equal numbers of target-present (TP) and target-absent (TA)
trials; its setup is therefore referred to as TA/TP—TA/TP (see Table 1). This “original” version of
the MMT was delivered to Group 3 as described above. Our two modified MMT versions both
involved the same response modalities and comprised the same number of TP trials as the
original. However, they differed in terms of whether the “easy” and “difficult” Target Recognition
Phases contained TA trials.
For Group 1, the (easier) Target Recognition Phase 1 was identical to the original MMT
(containing TA and TP trials), while the (more difficult) Target Recognition Phase 2 involved
only TP trials (with a doubled number to ensure equal number of trials across phases/blocks).
Group 1 is therefore referred to as TA/TP—TP. For Group 2 on the other hand, the experiment is
structured as the opposite as Group 1, with a TP—TA/TP structure: its Target Recognition Phase
1 contained only TP trials (but doubled compared to the MMT), followed by the original MMT
Target Recognition Phase 2.
To summarize, across Target Recognition Phases the three test versions used (Groups 1–3)
contain the same (decreasing) Target-to-Match Similarity (high; low), with varied Target
Prevalence (TA/TP; TP). For all versions, observers provided their responses by button press,
indicating whether any of the probes matches a target identity (by pressing 1, 2 or 3), or
not (by pressing 0). They were aware of the type of manipulation (High or Low Target-
to-Match Similarity/High or Low Target Prevalence) before each Testing Phase. When a
phase contained TP trials only (High Target Prevalence), observers could not respond by
pressing button 0, only buttons 1,2 or 3 could validate a response and pass to the next
stimuli.
Figure 2 Experimental design.
The experiment starts with
Target Learning followed by
Target Recognition. During
Target Learning, observers
sequentially encode three
images of a given target
identity, followed by a
3-alternative forced-choice
(3AFC) target test of the
encoded images. Target
learning of all six target
identities finishes with a final
20s review of target identities
using novel images. Target
Recognition comprises two
phases, which differ in their
Target-to-Match Similarity
(Phase 1: high; Phase 2:
low; see Methods). Target
Recognition Phases can differ
in terms of Target Prevalence,
i.e., they can either contain
only trials depicting targets
(Target-Present; TP), or
mixed trials (Target-Absent/
Target-Present; TA/TP). Our
three groups (see Table 1)
were subjected to different
experimental Contexts,
which represent our possible
combinations of Target
Prevalence (TP; TA/TP), across
Target Recognition Phases
with fixed order of Target-to-
Match Similarity (low, followed
by high).
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STATISTICAL ANALYSES
MEASURES
As across MMT versions, not all Target Recognition Phases included TA trials. These versions were
the result of the combination of Target Recognition Phases with different Target Prevalence.
Therefore, to compare performance between contexts and phases (by considering Hit Rate,
rather than Accuracy as the dependent variable), our analyses were conducted only on TP trials,
while TA trials (False Alarms or Correct Rejections) were not considered.
REPLICATION OF THE ORIGINAL MMT
First, to ensure construct validity, we compared our data obtained using the original MMT
version (which is equivalent to Group 3 regarding the experimental conditions: TA/TP—
TA/TP Target Prevalence combination) to those reported by Bate et al. (2018). To this end,
we compared Accuracy and Sensitivity (d’), as well as hit and correct rejection rates between
studies. Note that since, unfortunately, the original MMT’s authors could not provide their
observers’ individual data, we could only compare data between studies at the mean
Accuracy level via one-sample t-tests (wherein Bate et al.’s (2018) across-observer means
represent μ0).
LINEAR MIXED-EFFECTS MODELLING
To assess potential effects of Target-to-Match Similarity, Target Prevalence and Cultural Exposure
on observers’ hit rates, we successively fitted linear mixed effects models to observer-level
data (R, Version 4.0.5; R Core Team, 2013; lme4 package; Bates, Maechler, Bolker, & Walker,
2015), allowing us to compute each factor’s Bayesian Information Criterion (BIC). As a general
strategy, we began by fitting Hit Rate data to a null model (Model 0, including an intercept
term only). Subsequently, we compared it against more complex models, successively adding
a single fixed effect (i.e., Target-to-Match Similarity, or Target Prevalence) to each one, then
calculating the Bayes Factor (BF) between Models n and n+1 (where n denotes the last
favored—and least complex—model). We would then retain whichever model the BF favored
for subsequent comparisons. In any case where multiple models of rank n+1 were equally
favored over model n, the AIC was used to adjudicate between them by selecting the most
parsimonious among them. Finally, we added Cultural Exposure (and associated interactions)
to the most favored fixed-effects model as a random factor (since this was neither controlled
nor assigned) in the same iterative manner.
CONTEXT EFFECTS: TARGET-TO-MATCH SIMILARITY AND TARGET PREVALENCE
The models described above tested for effects of Target-to-Match Similarity and Target
Prevalence across the two modified versions of the MMT (Groups 1 and 2), and the original
MMT (Group 3). To assess the influence of Target Prevalence Context across Target-to-Match
Similarity, we compared each of our 3MT cohorts to our MMT cohort using the same strategy
outlined above, with two more sets of linear mixed-effects models. Effectively, these tested
the effects of changing Target Prevalence from Low to High or vice versa on performance in the
Low Target-to-Match Similarity. In all cases, following model selection, we compared relevant
marginal conditions for the significant factors with t-tests.
RESULTS
REPLICATION OF THE ORIGINAL MODELS MEMORY TEST (MMT)
First, comparing the mean performance of observers who completed the original MMT (in our
replication through Group 3) against results from Bate and colleagues (2018), we obtain similar
results overall. Despite obtaining generally higher means for overall Accuracy, Hit Rate, Correct
Rejection Rate as well as Sensitivity, t-tests comparing the samples’ means between studies
yielded no significant differences (see Table 2). Additionally, we confirmed the absence of a
statistical difference by calculating per measure the effect size (Cohen’s D, in Table 2) of the
difference across cohorts. Overall, these results suggest that (at the group level) observers in
Group 3 achieved comparable performance to the mean reported by Bate et al. (2018).
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SEPARATING EFFECTS OF TARGET-TO-MATCH SIMILARITY AND TARGET
PREVALENCE ON HIT RATE
We modeled the effects of hit rate as described in the Statistical Analyses section. Bayes
Factors comparing the models (see Figure 3) decisively support Model 2 compared to Models 0
or 1. Thus, we retained Model 2 (including Target-to-Match Similarity and Target Prevalence as
main effects on hit rate). A paired samples t-test yielded a significant difference between hit
rates observed in the high (Mean = .70, SD = .20) vs. low (Mean = .53, SD = .20) Target-to-Match
Similarity conditions (t(59) = 6.76, p < .05). As anticipated, observers’ hit rates were generally
lower during Target Recognition Phase 2, thereby confirming increased task difficulty via more
extreme ambient changes. An independent-samples t-test investigating the two conditions of
the Target Prevalence yielded a significant difference between high (Mean = .71 ± .19) and low
(Mean = .57 ± .21) Target Prevalence (t(118) = –3.55, p < .05): observers generally performed
better under high Target Prevalence scenarios.
CONTEXTUAL EFFECTS: TARGET-TO-MATCH SIMILARITY AND TARGET
PREVALENCE
We conducted separate model comparisons between the cohorts who completed modified
versions of the MMT (Group 1 and 2), and our original MMT cohort (Group 3) (for details, see
Statistical Analyses). Figure 4a displays groups’ mean hit rates for Target Recognition Phases
1 and 2 (across which Target-to-Match Similarity decreased); Figure 4b displays the results of
the multi-level models detailed below. Specifically, here we sought to determine whether the
effect of Context on hit rate depends on the presence of TA trials in Phase 1 or Phase 2.
For constant Phase 1 Context: Group 1 (TA/TP—TP) vs 3 (TA/TP—TA/TP)
To begin with, we considered the scenario where Phase 1 was identical between groups,
changing only during Phase 2 for Group 1. Having confirmed a general effect of target similarity
(Figure 3), we treated this as our zero-order model, and compared it against models including
a main effect of Context (Figure 4b; model 1a) and a Context by Similarity interaction (Figure
4b; model 1b). While Model 1a provides no better explanation than Model 0, we find decisive
evidence favoring Model 1b over Model 0. Overall, this suggests that the interaction between
Target Prevalence and Target-to-Match Similarity best explains observers’ pattern of hit rates.
Post-hoc independent-samples t-tests revealed no difference in hit rates for Phase 1 (High
Target-to-Match Similarity; t(37) = –.53, p > .05; M1 = .62 ± .20 vs. M3 = .66 ± .18) when Groups
initially experienced the same initial conditions (target absent on half of trials). However, in
Table 2 Comparison of
behavioral performance
between the cohort reported
for the original Models
Memory Test (Bate et
al., 2018) and our sample
(Group 3).
ORIGINAL
MMT N = 40
(33Y)
GROUP 3
N = 20
(37Y)
DIFFERENCE BETWEEN
MMT VERSIONS
EFFECT SIZE OF
DIFFERENCE
COHEN’S D
Mean ACC ± SD .54 ± .14 .57 ± .16 t(19) = 0.72, p = .4777 > .05 .16
Hit Rate ACC ± SD .51 ± .20 .53 ± .16 t(19) = 0.62, p = .5422 > .05 .14
Correct Rejection
Rate ACC ± SD
.57 ± .23 .60 ± .21 t(19) = 0.61, p = .5474 > .05 .14
d’ ± SD .26 ± .84 .38 ± .93 t(19) = 0.58, p = .38 > .05 .13
Figure 3 Multi-level models
per factor independently
of group. Numbers below
each model name represent
(in order) the Bayesian
information criterion (BIC),
the Bayes Factor (BF), and the
BF’s logarithmic expression
(Log10). Black font indicates
models showing better
evidence of explaining the
variance among participants
in comparison with the inferior
level’s model. The highest
model in black is gathered for
further analyses.
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Journal of Cognition
DOI: 10.5334/joc.339
Phase 2 (Low Target-to-Match Similarity), we find significantly higher hit rates for Group 1
(M = .60, SD = .14) than Group 3 (M = .41 ± .18), (t(37) = 3.56, p < .05). Overall, the observed
interaction effect suggests that completing Phase 1 including TA trials differentially influenced
Phase 2 Hit Rate, such that the change in context (i.e. when only TP trials were shown in Phase
2) influenced Hit Rate in Phase 2.
Phase 1 Context varied between Groups: Group 2 (TP—TA/TP) vs 3 (TA/TP—TA/TP)
Next, we sought to examine whether the effect of Similarity also depended on Context: would
hit rates in fact decrease following exposure to low (versus high) target prevalence during
Phase 1. The Bayes Factor between models including versus excluding Context as a factor
(either alone or interactively, while accounting for Similarity) favored neither one. However,
comparison of AIC between models suggests that the model including only the Context main
effect is the most parsimonious (ΔAIC = –7.3). Within Model 1aA, we find a main effect of
Target Prevalence Context. A post-hoc independent samples t-test of this effect revealed that
observers assigned to Group 2 performed significantly better than those in Group 3 ((t(80) =
3.39, p < .01); M2 = .70 ± .22 vs. M3 = .54 ± .216; t(80) = 3.39, p < .05).
Figure 4 Groups’ performance
and multi-level model results.
a. Mean hit rates per group
and Target Recognition Phase.
Multi-level model results
for b. Group 1 vs. Group 3,
and c. Group 2 vs. Group 3.
Numbers below each model
name represent (in order) the
Bayesian information criterion
(BIC), the Bayes Factor (BF),
and the BF’s logarithmic
expression (Log10). Black font
indicates models showing
better evidence of explaining
the variance among
participants in comparison
with the inferior level’s model.
The highest model in black is
gathered for further analyses.
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DISCUSSION
Our systematic investigation of Target Prevalence, Target-to-Match Similarity, and Context as
factors influencing neurotypical face recognition performance finds that TA trial prevalence
influences observers’ hit rates regardless of the levels of other factors. Overall, their inclusion
in MMT-type tasks deteriorates observers’ hit rates, which ought to be expected given the
results of visual search studies for non-face stimuli (Wolfe & Van Wert, 2010; Wolfe et al.,
2007). Practically speaking, our results suggest that, while inclusion of TA trials are important
in gauging sensitivity in FIP measures, these are likely prone to intra-observer bias. As such,
care should be taken to interpret performance measures while either controlling for TA trial
prevalence, or systematically varying it.
Aside from that, we did not find any interaction with Target Prevalence. As discussed below, this
suggests that response bias is unaffected by other factors that can cause variation in hit rate.
This is obviated by considering the effect of eliminating TA trials on response bias: observers’
decisions are then forced to be between target locations or response keys (not between signal
and noise), thus any residual bias no longer corresponds to a shift in criterion (preference for
reporting signal or noise), but purely in preference for one or another response button, or image
location. Consequently, studies including TA trials underestimate hit rates, and likely do not (or
cannot) control for this by any other manipulation (e.g., similarity between learned targets and
probe stimuli), since these effects are separable. Rather, systematic variation or control over
target prevalence are necessary to minimize criterion changes.
TARGET-TO-MATCH SIMILARITY
One of our goals was to investigate the effect of similarity between an encoded target identity
and its matching probe items in a modified MMT. We find increased hit rates between Target
Recognition Phases 1 and 2 (which shift from high to low Target-to-Match Similarity), closely
replicating Bate and colleagues’ (2018) originally reported results. The conditions experienced
by Group 1 of our study tightly mirror those of the original MMT, so it seems unlikely that the
between-group Context effects we find here are attributable to methodological differences
between studies.
We further find strong evidence for an effect of Target-To-Match Similarity; participants’
performance was better in the first Target Recognition Phase, where similarity was higher
compared to the second one. This aligns with previous studies suggesting that more pronounced
changes in the appearance of recently learned target identities negatively affect recognition
(Ellis, 1975; Patterson & Baddeley, 1977). Note, however, that the MMT’s experimental design
(Bate et al., 2018) involved a fixed order, i.e., higher followed by lower similarity across Target
Recognition Phases (vs. a potentially fully randomized trials order with respect to their Target-
to-Match Similarity).
TARGET PREVALENCE
Previous studies investigating the effect of Target Prevalence outside the domain of face
processing have reliably shown that the frequency of target (or signal) occurrence strongly
influences response bias, such that reporting of signals is commensurate with their prevalence
(Wolfe & Van Wert, 2010; Wolfe et al., 2007). We sought to determine the impact of TA trials
on face recognition performance by modifying the MMT. Its Target Recognition Phases involve
only TP trials, so we devised versions including equal proportions of TP and TA trials in either or
both Phases. Mirroring previous findings from the visual search literature mentioned above, we
observe reduced hit rates when TP trials are embedded among TA trials.
Overall, we believe that our findings concerning the negative impact of low Target Prevalence
on hit rates during face recognition extends to other FIP reliant (including applied) scenarios,
we anticipate observing inter-individual differences in the expression of this effect. Once
confirmed, this would support our view that task-specific training (e.g., of radiologists, luggage
screeners, law enforcement professionals) should include a combination of TP and TA trials, as
well as characterize the effect of target prevalence variations on individuals’ performance. In
addition to approximating real-world conditions, this could aid observers in guarding against
the decision biases they express during recognition tasks, and ideally reduce their impact in
applied settings.
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CONTEXT EFFECTS
Wolfe and colleagues (2007) have previously reported that visual search performance varies
with the frequency of a target’s occurrence and position. Specifically, initial training with high
(vs. low) Target Prevalence affected performance in a subsequent low prevalence phase. Our
final aim was to characterize this contextual carryover effect, in the context of face recognition
memory.
First, we found that Group 1 (TA/TP—TP) achieved higher Hit Rates than Group 3 (TA/TP—
TA/TP; original MMT) on average. Having been exposed to the identical procedure in the first
Target Recognition Phase (with low Target Prevalence), the only between-groups factor that
could explain this performance difference is Target Prevalence in the second Target Recognition
Phase, characterized by lower Target-to-Match Similarity. While Group 3 experienced low Target
Prevalence throughout both phases, Group 1 only experienced high Target Prevalence during
the second Target Recognition Phase. The effect of Target Prevalence between Groups 1 and 3
suggests that high Target Prevalence counteracts the increased difficulty due to lower Target-
to-Match Similarity across phases.
Second, to investigate a potential contextual effect, we compared the performance of Group
2 (TP—TA/TP) and Group 3 (TA/TP—TA/TP). Unlike the previous comparison, the favored model
accounted for only the Context, but not the interaction between Context and Target-to-Match
Similarity. This was explained by a main effect of Context, due to Group 2 exhibiting significantly
better performance than Group 3. If Group 2’s observers had highest Hit Rates for both phases
compared to those from Group 3, we cannot account for any specific contextual effects
regarding Phase 1 or Phase 2. This is because of the relative non-significance of the model 1b
including the interaction between Context and Target-to-Match Similarity (Figure 4b; model 1b).
Consequently, we can only talk about a general contextual effect between both groups on the
Hit Rate.
Here, in line with our expectation, and similar to the aforementioned findings (Wolfe et al., 2007),
Target Prevalence in the first Target Recognition Phase affected performance in the second
phase. We observed a behavioral advantage for initial high (TP) vs. low (TA/TP) prevalence, with
the prior leading to better performance at a second low prevalence (TA/TP) phase. Thus, when
varying Target Prevalence dichotomously, we observed a systematic response bias related to
the target’s occurrence.
LIMITATIONS
The present study was designed to explore factors potentially affecting face recognition
performance in the MMT (Bate et al., 2018), which was recently introduced as a more ecological
alternative to the well-established CFMT+ (Russell et al., 2009). While our observations support
the notion of important contextually determined biases, these findings arose in the context of
a restricted set of experimental conditions.
First, as mentioned previously, we did not implement all possible contexts, thereby lacking the
TP–TP condition. Second, following the original MMT design, across Target Recognition Phases,
Target-to-Match Similarity always decreased (high followed by low); the opposite direction
was never tested. A complete experimental design involving all possible combinations would
entail four different contexts (TP—TP, TP—TA/TP, TA/TP—TP and TA/TP—TA/TP) as well as
counterbalanced orders of the Target-to-Match Similarity and the Target Prevalence. This would
preclude the possibility of a cohort or confounding effect. Third and finally, we treated Target
Prevalence dichotomously, and further studies are needed that systematically vary the ratio
of TP:TA trails within TA/TP contexts. Target Prevalence effects in FIP and other visual search
tasks are relatively ubiquitous and domain-general. To determine why target recognition
performance is negatively affected by low Target Prevalence, Wolfe and colleagues’ (Wolfe &
Van Wert, 2010; Wolfe et al., 2007) analyzed signal sensitivity (d’), as well as response times for
visual search tasks. They concluded that prevalence influences decision criterion and, therefore,
the perceptual decisions about an item.
Our findings were obtained in the context of a recognition task, which is analogous to a 3
items visual search. As such, the presently observed effects would be likely to differ in tasks
where simultaneous matching is probed, i.e., those devoid of a memory component. Of note,
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DOI: 10.5334/joc.339
a learning effect across the trials cannot be excluded. Indeed, observers assigned to Group 2
were exposed to 45 TP trials (high Target Prevalence) during Phase 1. As such they had roughly
twice the amount of exposure to target identities as compared to observers in Group 3 (exposed
to TA/TP trials in the low Target Prevalence Phase 1). To eliminate such a potential effect, a more
complex design would be required to ensure comparable TP exposure.
Finally, our analyses focused on the only metric comparable given the between-group variation
in Target Prevalence across Target Recognition Phases: hit rate. Future studies could include an
extended experimental design, via introduction of a fourth TP––TP context, in combination with
a within-observer approach, whereby participants complete different contexts (e.g. TP—TA/TP
and TA/TP—TP), and sensitivity analyses.
CONCLUSION
Inspired by visual search studies reporting variations in decisional biases and error rates related
to varied Target Prevalence, the present study sought to address generally acknowledged, but
empirically under-investigated factors assumed to influence face recognition performance:
Target Prevalence, Target-to-Match Similarity and contextual effects. We reasoned that all are
crucial across various applied visual tasks, including radiology, baggage screening, and suspect
identification in law enforcement. Our findings suggest that all three factors influence visual
recognition performance, but not necessarily interactively. This has general implications for test
development and training of professionals performing visual tasks in more realistic situations.
With the mentioned factors, we propose means in which this work could be extended to allow
a more fine-grained investigation of the reported effects, including an individual differences
approach.
ABBREVIATIONS
Face identity processing (FIP); Artificial intelligence (AI); Target present (TP); Target absent (TA).
DATA ACCESSIBILITY STATEMENT
All data and code can be found on the accompanying OSF project for this publication (https://
osf.io/3swhx/).
ETHICS AND CONSENT
All procedures were approved by the Ethics Committee of the University of Fribourg (Switzerland)
(approval number 473); participants were healthy volunteers who did not receive financial
compensation for participation. Experiments were completed online (administered on the AFC
Lab’s bespoke testing platform, or Testable). Each participant was provided a digital version of
the informed consent document and given unlimited time to read the document and provide
their consent prior to beginning each of the two sets of behavioral experiments.
ACKNOWLEDGEMENTS
We thank Caren (Sasha) Lasrado for her support in designing and running the experiments, all
volunteers for their participation, and Sarah Bate for providing the original MMT.
FUNDING INFORMATION
MR is supported by a Swiss National Science Foundation PRIMA (Promoting Women in Academia)
grant (PR00P1_179872).
COMPETING INTERESTS
The authors have no competing interests to declare.
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AUTHOR CONTRIBUTIONS
LB: Data curation, Formal analysis, Validation, Writing – original draft, Writing – review &
editing. JN: Formal analysis, Validation, Writing – review & editing. MR: Conceptualization,
Data curation, Funding acquisition, Methodology, Project administration, Resources, Software,
Supervision, Visualization, Writing – original draft, Writing – review & editing.
AUTHOR AFFILIATIONS
Lionel Boudry orcid.org/0000-0002-7061-3369
Applied Face Cognition Lab, University of Lausanne, Lausanne, Switzerland
Jeffrey D. Nador orcid.org/0000-0002-6502-7226
Applied Face Cognition Lab, University of Lausanne, Lausanne, Switzerland
Meike Ramon orcid.org/0000-0001-5753-5493
Applied Face Cognition Lab, University of Lausanne, Lausanne, Switzerland
REFERENCES
Bate, S., Frowd, C., Bennetts, R., Hasshim, N., Murray, E., Bobak, A., Willis, H., & Richards, S. (2018).
Applied screening tests for the detection of superior face recognition. Cognitive Research: Principles
and Implications, 3. DOI: https://doi.org/10.1186/s41235-018-0116-5
Bates, D., Mächler, M., Bolker, B., & Walker, S. (2015). Fitting Linear Mixed-Effects Models Using lme4.
Journal of Statistical Software, 67(1), 1–48. DOI: https://doi.org/10.18637/jss.v067.i01
Bobak, A. K., Hancock, P. J., Hilker, Z., Mestry, N., Bate, P. S., Jones, A., & Watt, R. (under review). Data
driven approaches can tell us as much about the processes underlying face cognition as the quality of
the available tests and data sets allows. Where do we xgo from here? DOI: https://doi.org/10.17605/
OSF.IO/5K9NY
Bruce, V., Henderson, Z., Greenwood, K., Hancock, P., Burton, A., & Miller, P. (1999). Verification of face
identities from iImages captured on video. Journal of Experimental Psychology: Applied, 5, 339–360.
DOI: https://doi.org/10.1037/1076-898X.5.4.339
Ellis, H. D. (1975). Recognizing Faces. British Journal of Psychology, 66(4), 409–426. DOI: https://doi.
org/10.1111/j.2044-8295.1975.tb01477.x
Evans, K. K., Birdwell, R. L., & Wolfe, J. M. (2013). If You Don’t Find It Often, You Often Don’t Find It:
Why Some Cancers Are Missed in Breast Cancer Screening. PLOS ONE, 8(5), e64366. DOI: https://doi.
org/10.1371/journal.pone.0064366
Fishel, J., Levine, M., & Date, J. (2015, June). Undercover DHS Tests Find Security Failures at US Airports.
ABC News. Retrieved from http:// abcnews.go.com/US/exclusive-undercover-dhs-tests-find-
widespreadsecurity-failures/story?id_31434881
Fysh, M. C., & Ramon, M. (2022). Accurate but inefficient: Standard face identity matching tests
fail to identify prosopagnosia. Neuropsychologia, 165, 108119. DOI: https://doi.org/10.1016/j.
neuropsychologia.2021.108119
Fysh, M. C., Stacchi, L., & Ramon, M. (2020). Differences between and within individuals, and
subprocesses of face cognition: Implications for theory, research and personnel selection. Royal
Society Open Science, 7(9), 200233. DOI: https://doi.org/10.1098/rsos.200233
Gur, D., Sumkin, J. H., Rockette, H. E., Ganott, M., Hakim, C., Hardesty, L., Poller, W. R., Shah, R., &
Wallace, L. (2004). Changes in Breast Cancer Detection and Mammography Recall Rates After the
Introduction of a Computer-Aided Detection System. JNCI: Journal of the National Cancer Institute,
96(3), 185–190. DOI: https://doi.org/10.1093/jnci/djh067
Jenkins, R., & Burton, A. M. (2011). Stable face representations. Philosophical Transactions of the Royal
Society B: Biological Sciences, 366(1571), 1671–1683. DOI: https://doi.org/10.1098/rstb.2010.0379
Kristjánsson, Á., & Campana, G. (2010). Where perception meets memory: A review of repetition
priming in visual search tasks. Attention, Perception, & Psychophysics, 72(1), 5–18. DOI: https://doi.
org/10.3758/APP.72.1.5
Linka, M., Broda, M. D., Alsheimer, T., de Haas, B., & Ramon, M. (2022). Characteristic fixation biases in
Super-Recognizers. Journal of Vision, 22(8), 17. DOI: https://doi.org/10.1167/jov.22.8.17
Matthews, C. M., & Mondloch, C. J. (2018). Finding an unfamiliar face in a line-up: Viewing multiple
images of the target is beneficial on target-present trials but costly on target-absent trials. British
Journal of Psychology, 109(4), 758–776. DOI: https://doi.org/10.1111/bjop.12301
Mayer, M., & Ramon, M. (2023). Improving forensic perpetrator identification with Super-Recognizers.
PsyArXiv. DOI: https://doi.org/10.31234/osf.io/9zq7j
Meissner, C. A., & Brigham, J. C. (2001). Thirty years of investigating the own-race bias in memory
for faces: A meta-analytic review. Psychology, Public Policy, and Law, 7, 3–35. DOI: https://doi.
org/10.1037/1076-8971.7.1.3
14
Boudry et al.
Journal of Cognition
DOI: 10.5334/joc.339
Nador, J. D., Alsheimer, T. A., Gay, A., & Ramon, M. (2021a). Image or Identity? Only Super-recognizers’
(Memor)Ability is Consistently Viewpoint-Invariant. Swiss Psychology Open: The Official Journal of the
Swiss Psychological Society, 1(1), Art. 1. DOI: https://doi.org/10.5334/spo.28
Nador, J. D., Vomland, M., Thielgen, M. M., & Ramon, M. (2022). Face recognition in police officers:
Who fits the bill? Forensic Science International: Reports, 5, 100267. DOI: https://doi.org/10.1016/j.
fsir.2022.100267
Nador, J. D., Zoia, M., Pachai, M. V., & Ramon, M. (2021b). Psychophysical profiles in super-recognizers.
Scientific Reports, 11(1), Art. 1. DOI: https://doi.org/10.1038/s41598-021-92549-6
Nakashima, R., Kobayashi, K., Maeda, E., Yoshikawa, T., & Yokosawa, K. (2013). Visual Search of Experts
in Medical Image Reading: The Effect of Training, Target Prevalence, and Expert Knowledge. Frontiers
in Psychology, 4. https://www.frontiersin.org/articles/10.3389/fpsyg.2013.00166. DOI: https://doi.
org/10.3389/fpsyg.2013.00166
Patterson, K. E., & Baddeley, A. D. (1977). When face recognition fails. Journal of Experimental
Psychology: Human Learning and Memory, 3, 406–417. DOI: https://doi.org/10.1037/0278-
7393.3.4.406
Peltier, C., & Becker, M. W. (2016). Decision processes in visual search as a function of target prevalence.
Journal of Experimental Psychology: Human Perception and Performance, 42, 1466–1476. DOI: https://
doi.org/10.1037/xhp0000248
Puri, K. S., Suresh, K. R., Gogtay, N. J., & Thatte, U. M. (2009). Declaration of Helsinki, 2008: Implications
for stakeholders in research. Journal of Postgraduate Medicine, 55(2), 131. DOI: https://doi.
org/10.4103/0022-3859.52846
R Core Team. (2013). R: A Language and Environment for Statistical Computing. Vienna: R Foundation for
Statistical Computing. http://www.R-project.org/
Ramon, M. (2021). Super-Recognizers – a novel diagnostic framework, 70 cases, and
guidelines for future work. Neuropsychologia, 158, 107809. DOI: https://doi.org/10.1016/j.
neuropsychologia.2021.107809
Ramon, M., Bobak, A. K., & White, D. (2019). Super-recognizers: From the lab to the world and back again.
British Journal of Psychology, 110(3), 461–479. DOI: https://doi.org/10.1111/bjop.12368
Ramon, M., Busigny, T., Gosselin, F., & Rossion, B. (2016). All new kids on the block? Impaired holistic
processing of personally familiar faces in a kindergarten teacher with acquired prosopagnosia. Visual
Cognition, 24(5–6), 321–355. DOI: https://doi.org/10.1080/13506285.2016.1273985
Ramon, M., & Gobbini, M. I. (2018). Familiarity matters: A review on prioritized processing of personally
familiar faces. Visual Cognition, 26(3), 179–195. DOI: https://doi.org/10.1080/13506285.2017.140
5134
Ramon, M., & Rjosk, S. (2022). Sure® – Berlin Test for Super-Recognizer Identification online bestellen|978-
3-86676-762-1|MANZ. (2022). https://shop.manz.at/shop/products/9783866767621
Rossion, B. (2022a). Twenty years of investigation with the case of prosopagnosia PS to understand
human face identity recognition. Part I: Function. Neuropsychologia, 173, 108278. DOI: https://doi.
org/10.1016/j.neuropsychologia.2022.108278
Rossion, B. (2022b). Twenty years of investigation with the case of prosopagnosia PS to understand
human face identity recognition. Part II: Neural basis. Neuropsychologia, 173, 108279. DOI: https://
doi.org/10.1016/j.neuropsychologia.2022.108279
Rossion, B., Retter, T. L., & Liu-Shuang, J. (2020). Understanding human individuation of unfamiliar
faces with oddball fast periodic visual stimulation and electroencephalography. European Journal of
Neuroscience, 52(10), 4283–4344. DOI: https://doi.org/10.1111/ejn.14865
Russell, R., Duchaine, B., & Nakayama, K. (2009). Super-recognizers: People with extraordinary face
recognition ability. Psychonomic Bulletin & Review, 16(2), 252–257. DOI: https://doi.org/10.3758/
PBR.16.2.252
Stacchi, L., Huguenin-Elie, E., Caldara, R., & Ramon, M. (2020). Normative data for two challenging tests
of face matching under ecological conditions. Cognitive Research: Principles and Implications, 5(1), 8.
DOI: https://doi.org/10.1186/s41235-019-0205-0
Transportation Security Administration. (2015). EXCLUSIVE: https://abcnews.go.com/US/exclusive-
undercover-dhs-tests-find-widespread-security-failures/story?id=31434881
Wells, G. L., & Olson, E. A. (2003). Eyewitness Testimony. Annual Review of Psychology, 54(1), 277–295.
DOI: https://doi.org/10.1146/annurev.psych.54.101601.145028
Wolfe, J. M., Horowitz, T. S., Van Wert, M. J., Kenner, N. M., Place, S. S., & Kibbi, N. (2007). Low target
prevalence is a stubborn source of errors in visual search tasks. Journal of Experimental Psychology:
General, 136, 623–638. DOI: https://doi.org/10.1037/0096-3445.136.4.623
Wolfe, J. M., & Van Wert, M. J. (2010). Varying Target Prevalence Reveals Two Dissociable Decision
Criteria in Visual Search. Current Biology, 20(2), 121–124. DOI: https://doi.org/10.1016/j.
cub.2009.11.066
Young, A. W., & Ellis, H. D., (1989). Handbook of Research on Face Processing-1st Edition. https://www.
elsevier.com/books/handbook-of-research-on-face-processing/young/978-0-444-87143-5
15
Boudry et al.
Journal of Cognition
DOI: 10.5334/joc.339
TO CITE THIS ARTICLE:
Boudry, L., Nador, J. D.,
& Ramon, M. (2024).
Determinants of Face
Recognition: The Role of Target
Prevalence and Similarity.
Journal of Cognition,
7(1):
27, pp. 1–15. DOI: https://doi.
org/10.5334/joc.339
Submitted: 28 June 2023
Accepted: 13 December 2023
Published: 21 February 2024
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Yovel, G. (2016). Neural and cognitive face-selective markers: An integrative review. Neuropsychologia, 83,
5–13. DOI: https://doi.org/10.1016/j.neuropsychologia.2015.09.026
Zimmermann, A., Lorenz, A., & Oppermann, R. (2007). An Operational Definition of Context. In B. Kokinov,
D. C. Richardson, T. R. Roth-Berghofer & L. Vieu (Éds.), Modeling and Using Context (pp. 558–571).
Springer. DOI: https://doi.org/10.1007/978-3-540-74255-5_42
... Indeed, criminal investigation line-ups may not always contain the target identity in question. Therefore, recently, Boudry, Nador, and Ramon (2023) systematically investigated the effect of target prevalence on observers' face recognition performance using the same 3-alternative forced-choice memory paradigm as the CFMT (Russell et al., 2009). Mirroring findings from within the field of visual search (Wolfe et al., 2007;Wolfe & Van Wert, 2010), the authors report that decreased target occurrence was associated with lower recognition performance. ...
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About a decade ago, Super-Recognizers (SRs) were first described as individuals with exceptional face identity processing abilities. Since then, various tests have been developed or adapted to assess individuals’ abilities and identify SRs. The extant literature suggests that SRs may be beneficial in police tasks requiring individual identification. However, in reality, the performance of SRs has never been examinedusing authentic forensic material. This not only limits the external validity of test procedures used to identify SRs, but also claims concerning their deployment in policing. Here, we report the first-ever investigation of SRs’ ability to identify perpetrators using authentic case material. We report the data of 73 SRs and 45 control participants. These include (a) performance on three challenging tests of face identity processing recommended by Ramon (2021) for SR identification; (b) performance for perpetrator identification using four CCTV sequences depicting five perpetrators and police line-ups created for criminal investigation purposes. Our findings demonstrate that the face identity processing tests used here are valid in measuring such abilities and identifying SRs. Moreover, SRs excel at perpetrator identification relative to control participants, with more correct perpetrator identifications, the better their performance across lab tests. These results provide external validity for the recently proposed diagnostic framework and its tests used for SR identification (Ramon,2021). This study provides the first empirical evidence that SRs identified using these measures can be beneficial for forensic perpetrator identification. We discuss theoretical and practical implications for law enforcement, whose procedures can be improved via a human-centric approach centered around individuals with superior abilities.
... Indeed, criminal investigation line-ups may not always contain the target identity in question. Therefore, recently, Boudry et al. (22) systematically investigated the effect of target prevalence on observers' face recognition performance using the same 3alternative forced-choice memory paradigm as the CFMT (1). Mirroring findings from within the field of visual search (23,24), the authors report that decreased target occurrence was associated with lower recognition performance. ...
Article
About a decade ago, Super-Recognizers (SRs) were first described as individuals with exceptional face identity processing abilities. Since then, various tests have been developed or adapted to assess individuals' abilities and identify SRs. The extant literature suggests that SRs may be beneficial in police tasks requiring individual identification. However, in reality, the performance of SRs has never been examined using authentic forensic material. This not only limits the external validity of test procedures used to identify SRs, but also claims concerning their deployment in policing. Here, we report the first-ever investigation of SRs' ability to identify perpetrators using authentic case material. We report the data of 73 SRs and 45 control participants. These include (a) performance on three challenging tests of face identity processing recommended by Ramon (2021) for SR identification; (b) performance for perpetrator identification using four CCTV sequences depicting five perpetrators and police line-ups created for criminal investigation purposes. Our findings demonstrate that the face identity processing tests used here are valid in measuring such abilities and identifying SRs. Moreover, SRs excel at perpetrator identification relative to control participants, with more correct perpetrator identifications, the better their performance across lab tests. These results provide external validity for the recently proposed diagnostic framework and its tests used for SR identification (Ramon, 2021). This study provides the first empirical evidence that SRs identified using these measures can be beneficial for forensic perpetrator identification. We discuss theoretical and practical implications for law enforcement, whose procedures can be improved via a human-centric approach centered around individuals with superior abilities.
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Neurotypical observers show large and reliable individual differences in gaze behavior along several semantic object dimensions. Individual gaze behavior towards faces has been linked to face identity processing, including that of neurotypical observers. Here, we investigated potential gaze biases in Super-Recognizers (SRs) - individuals with exceptional face identity processing skills. 10 SRs, identified with a novel conservative diagnostic framework, and 43 controls freely viewed 700 complex scenes, depicting more than 5000 objects. First, we tested whether SRs vs. controls differ in fixation biases along four semantic dimensions: Faces, Text, objects being Touched and Bodies. Second, we tested potential group differences in fixation biases towards eyes and mouths. Finally, we tested whether SRs show less intra- and inter-individual variability with regard to their preferred vertical fixation position in faces. SRs showed a stronger gaze bias towards Faces and away from Text and Touched objects, starting from the first fixation onwards. Further, SRs spent a significantly smaller proportion of first fixations and dwell time towards faces on Mouths but did not differ in dwell time or first fixations devoted to eyes. Face fixation of SRs also fell significantly closer to the theoretical optimal fixation point for identification, just below the eyes. Our findings suggest that reliable superiority for face identity processing is accompanied by early fixation biases towards faces and preferred saccadic landing positions close to the theoretical optimum for face identification. We discuss future directions to investigate the functional basis of individual fixation behavior and face identity processing ability.
Article
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Facial identity matching ability varies widely, ranging from prosopagnosic individuals (who exhibit profound impairments in face cognition/processing) to so-called super-recognizers (SRs), possessing exceptional capacities. Yet, despite the often consequential nature of face matching decisions—such as identity verification in security critical settings—ability assessments tendentially rely on simple performance metrics on a handful of heterogeneously related subprocesses, or in some cases only a single measured subprocess. Unfortunately, methodologies of this ilk leave contributions of stimulus information to observed variations in ability largely un(der)specified. Moreover, they are inadequate for addressing the qualitative or quantitative nature of differences between SRs’ abilities and those of the general population. Here, therefore, we sought to investigate individual differences—among SRs identified using a novel conservative diagnostic framework, and neurotypical controls—by systematically varying retinal availability, bandwidth, and orientation of faces’ spatial frequency content in two face matching experiments. Psychophysical evaluations of these parameters’ contributions to ability reveal that SRs more consistently exploit the same spatial frequency information, rather than suggesting qualitatively different profiles between control observers and SRs. These findings stress the importance of optimizing procedures for SR identification, for example by including measures quantifying the consistency of individuals’ behavior.
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A face’s memorability refers to the unique combination of its intrinsic visual features facilitating its later recognition. Despite considerable variation in face recognition ability amongst the general population, individuals show substantial concordance regarding the memorability of various faces. And, when the viewpoints across which identities are seen at encoding and recognition differ, such agreement persists, though to a lesser extent. Consequently, face recognition cannot rely solely on image-dependent encoding; individuals must extract some invariant facial information, robust to changes in viewpoint, to do so consistently. However, whether such consistency covaries with overall face processing ability is unclear. Here, therefore, in two experiments we tested recognition of (i) implicitly encoded face images and (ii) explicitly encoded identities in a group of normal control observers against a group of “Super-Recognizers” (SRs) who possess exceptional face processing skills. When implicit encoding was surreptitiously solicited, recognition of studied images was comparable between groups. Yet, when encoding was explicitly solicited, SRs more accurately recognized studied identities across viewpoint changes than normal observers. Critically, image-dependent information could only inform recognition in the first experiment, whereas viewpoint-invariant information could inform recognition consistently in both. Individualized profiles of observers’ performance (as a function of stimulus memorability) reveal that only SRs performed consistently between experiments. We suggest that SRs’ unique capacity for utilizing viewpoint-invariant information for recognition, regardless of encoding conditions, is rooted in fundamentally more accurate and robust representations of identity-based memorability. These results invite a reinterpretation of face memorability that describes viewpoint-invariant information, diagnostic of facial identity representations in memory.
Preprint
About a decade ago, Super-recognizers were first descirbed as individuals with exceptional face identity processing abilities. Since then, various tests have been developed or adapted to assess individuals' face identity processing abilities and identify Super-Recognizers. The extent literature suggests that Super-Recognizers may be beneficial in police tasks concerning individual identification. However, in reality, the performance of Super-Recognizers has never been examined using authentic forensic material. This not only limits external validity of test procedures used to identify Super-Recognizers, but also claims concerning their deployment in policing. Here, we report the first ever investigation of Super-Recognizers' ability in identifying perpetrators using authentic case material. We report the data of 73 Super-Recognizers and 45 control participants on three challenging tests of face identity processing recommended by Ramon (2021), and their performance for perpetrator identification using four CCTV sequences depicting five perpetrators. Our findings demonstrate that face identity processing tests are valid in measuring such abilities and identify Super-Recognizers. Moreover, Super-Recognizers excel at pertrator identification relative to control participants with more correct identifications in the forensic CCTV sequences, the better performance across tests of face identity processing was. These results provide external validity for tests proposed as diagnostic criteria for Super-Recognizer identificiation (Ramon, 2021). They furthermore represent the first empirical evidence that Super-Recognizers identified using these measures can be beneficial for forensic perpetrator identification. We discuss theoretical and practical implications for law enforcement, whose procedures can be improved via a human-centric approach centered around individuals with an innate ability.
Article
Following traumatic brain injury in adulthood, Pierrette Sapey (PS) became suddenly unable to recognize the identity of people from their faces. Thanks to her remarkable recovery of general brain function, liveliness, and willingness to be tested, PS's case of prosopagnosia has been extensively studied for more than 20 years. This investigation includes hundreds of hours of behavioral data collection that provide information about the nature of human face identity recognition (FIR). Here a theory-driven extensive review of behavioral and eye movement recording studies performed with PS is presented (part I). The specificity of PS's recognition disorder to the category of faces, i.e., with preserved visual object (identity) recognition, is emphasized, arguing that isolating this impairment is necessary to define prosopagnosia, offering a unique window to understand the nature of human FIR. Studies performed with both unfamiliar and experimentally or naturally familiar faces show that PS, while being able to perceive both detailed diagnostic facial parts and a coarse global facial shape, can no longer build a relatively fine-grained holistic visual representation of a face, preventing its efficient individuation. Her mandatory part-by-part analytic behavior during FIR causes increased difficulties at extracting diagnostic cues from the crowded eye region of the face, but also from relative distances between facial parts and from 3D shape more than from surface cues. PS's impairment is interpreted here for the first time in terms of defective (access to) cortical memories of faces following brain damage, causing her impaired holistic perception of face individuality. Implications for revising standard neurofunctional models of human face recognition and evaluation of this function in neurotypical individuals are derived.
Article
Patient PS sustained her dramatic brain injury in 1992, the same year as the first report of a neuroimaging study of human face recognition. The present paper complements the review on the functional nature of PS's prosopagnosia (part I), illustrating how her case study directly, i.e., through neuroimaging investigations of her brain structure and activity, but also indirectly, through neural studies performed on other clinical cases and neurotypical individuals, inspired and constrained neural models of human face recognition. In the dominant right hemisphere for face recognition in humans, PS's main lesion concerns (inputs to) the inferior occipital gyrus (IOG), in a region where face-selective activity is typically found in normal individuals (‘Occipital Face Area’, OFA). Her case study initially supported the criticality of this region for face identity recognition (FIR) and provided the impetus for transcranial magnetic stimulation (TMS), intracerebral electrical stimulation, and cortical surgery studies that have generally supported this view. Despite PS's right IOG lesion, typical face-selectivity is found anteriorly in the middle portion of the fusiform gyrus, a hominoid structure (termed the right ‘Fusiform Face Area’, FFA) that is widely considered to be the most important region for human face recognition. This finding led to the original proposal of direct anatomico-functional connections from early visual cortices to the FFA, bypassing the IOG/OFA (lulu), a hypothesis supported by further neuroimaging studies of PS, other neurological cases and neuro-typical individuals with original visual stimulation paradigms, data recordings and analyses. The proposal of a lack of sensitivity to face identity in PS's right FFA due to defective reentrant inputs from the IOG/FFA has also been supported by other cases, functional connectivity and cortical surgery studies. Overall, neural studies of, and based on, the case of prosopagnosia PS strongly question the hierarchical organization of the human neural face recognition system, supporting a more flexible and dynamic view of this key social brain function.
Article
Accurate face identity processing (FIP) is a critical component of security professions. Unfortunately, however, rapid face matching as required in real-life situations such as passport controls cannot be improved via training. While here accuracy is a high priority, it is neither the only, nor most important performance-measure. Officers must process high-throughput information as efficiently as possible – accurately and rapidly. In scenarios with grave public safety implications, however, efficiency is not sufficient. Suspect surveillance and mass-data analysis in criminal investigations also demand processing ample sensitive material consistently over extended periods. Police agencies have sought to optimize operations through personnel selection targeting FIP abilities. Yet to date, the lab-based tests researchers have proffered neither reflect officers’ specific tasks, nor the efficiency and consistency critical to accomplishing them. Therefore, we aimed to benchmark the three most challenging FIP tests available against two work-samples — tasks developed in consultation with police practitioners to measure specific, situationally critical performance. We solicited participation from 390 police officers from Regional Police and Criminal Investigation Departments, yielding a representative sample of 114 participating Protection Police Officers, Mass Data Analysts, and Search Unit Members who regularly employ FIP skills in their work. Data-driven analyses of officers’ FIP abilities revealed that work-sample efficiency and consistency represented most relevant dimensions of variation, and accounted for lab-test performance. Furthermore, performance on either work-sample was better predicted by performance on the other, than by lab-based test scores. This demonstrates the limitations of lab-based tests for applied settings, and stresses the need for predicting police officers’ FIP abilities through contextually and practically relevant performance measures.
Article
In recent years, the number of face identity matching tests in circulation has grown considerably and these are being increasingly utilized to study individual differences in face cognition. Although many of these tests were designed for testing typical observers, recent studies have begun to utilize general-purpose tests for studying specific, atypical populations (e.g., super-recognizers and individuals with prosopagnosia). In this study, we examined the capacity of four tests requiring binary face-matching decisions to study individual differences between healthy observers. Uniquely, we used performance of the patient PS (Rossion, 2018), a well-documented case of acquired prosopagnosia (AP), as a benchmark. Two main findings emerged: (i) PS could exhibit typical rates of accuracy in all tests; (ii) compared to age-matched controls and when considering both accuracy and speed to account for potential trade-offs, only the KFMT — but not the EFCT, PICT or GFMT — was able to detect PS’s severe impairment. These findings reflect the importance of considering both accuracy and response times to measure individual differences in face matching, and the need for comparing tests in terms of their sensitivity, when used as a measure of human cognition and brain functioning.
Article
When you hear the word Super-Recognizer, you may think of comic-book-hero-esque agents searching the underground to find people who went missing decades ago. Compared to this fantasy, the reality seems somewhat less exciting. Super-Recognizers (SRs) were initially reported a decade ago as a collateral while developing tests for developmental prosopagnosia. Today, the topic of SRs sparks interest from groups seeking to enhance scientific knowledge, public safety, or their monetary gain. With no immediate consequences of erroneous SR-identification, there has been no pressure to establish a clear SR-definition. This promotes heterogenous empirical evidence and the proliferation of unsupported claims in the media. Not only is this status quo unfortunate, it stands in opposition to the potential of special populations – both for science and application. SRs are a special population with imminent real-world value that can advance our understanding of brain functioning. To exploit their potential, I propose a needed formal framework for SR-diagnosis, and introduce 70 cases identified based hereupon. These cases represent the core of a growing SR cohort, studied in my lab in the course of a long-term, multi-methodological research agenda involving academic and government collaborators. Finally, I provide recommendations for those interested in SR work, and highlight current caveats and future challenges.
Article
To investigate face individuation (FI), a critical brain function in the human species, an oddball fast periodic visual stimulation (FPVS) approach was recently introduced (Liu‐Shuang et al., 2014). In this paradigm, an image of an unfamiliar “base” facial identity is repeated at a rapid rate F (e.g., 6 Hz) and different unfamiliar “oddball” facial identities are inserted every nth item, at a F/n rate (e.g., every 5th item, 1.2 Hz). This stimulation elicits FI responses at F/n and its harmonics (2F/n , 3F/n, etc.), reflecting neural discrimination between oddball vs. base facial identities, which is quantified in the frequency‐domain of the electroencephalogram (EEG). This paradigm, used in 20 published studies, demonstrates substantial advantages for measuring FI in terms of validity, objectivity, reliability, and sensitivity. Human intracerebral recordings suggest that this FI response originates from neural populations in the lateral inferior occipital and fusiform gyri, with a right hemispheric dominance consistent with the localization of brain lesions specifically affecting facial identity recognition (prosopagnosia). Here we summarize the contributions of the oddball FPVS framework towards understanding FI, including its (a)typical development, with early studies supporting the application of this technique to clinical testing (e.g., Autism Spectrum Disorder). This review also includes an in‐depth analysis of the paradigm’s methodology, with guidelines for designing future studies. A large‐scale group analysis compiling data across 130 observers provides insights into the oddball FPVS FI response properties. Overall, we recommend the oddball FPVS paradigm as an alternative approach to behavioral or traditional event‐related‐potential EEG measures of face individuation.