Brain and Cognition 45, 357–377 (2001)doi:10.1006/brcg.2000.1272, available online at http://www.idealibrary.com on

An ERP Study of Famous Face IncongruityDetection in Middle Age

Laurence Chaby,* Boutheina Jemel,* Nathalie George,† Bernard Renault,*and Nicole Fiori‡

*Unite de Neurosciences Cognitives et Imagerie Cerebrale, CNRS UPR 640, LENA, Hopital de laSalpetriere, 47 bd de l’Hopital, 75651 Paris cedex 13, France; †CNRS UPR 640, LENA &

Universite Paris VIII, Saint-Denis, France; and ‡CNRS UPR 640, LENA & Universite Paris V,Boulogne Billancourt, France

Age-related changes in famous face incongruity detection were examined in middle-aged(mean 5 50.6) and young (mean 5 24.8) subjects. Behavioral and ERP responses were re-corded while subjects, after a presentation of a ‘‘prime face’’ (a famous person with the eyesmasked), had to decide whether the following ‘‘test face’’ was completed with its authenticeyes (congruent) or with other eyes (incongruent). The principal effects of advancing agewere (1) behavioral difficulties in discriminating between incongruent and congruent faces;(2) a reduced N400 effect due to N400 enhancement for both congruent and incongruentfaces; (3) a latency increase of both N400 and P600 components. ERPs to primes (face encod-ing) were not affected by aging. These results are interpreted in terms of early signs of aging. 2001 Academic Press

Key Words: aging; faces; incongruity; priming; memory; ERPs; N170; N400; P600.

INTRODUCTION

It is commonly accepted that cognitive functions, including perceptual processes,attention, memory, etc., fade with age, and that this is an inevitable part of the agingprocess (Spirduso, 1995). The relevant literature on aging is extremely large, provid-ing substantial evidence that accuracy rates and response latencies in cognitive testsare respectively impaired and delayed in elderly (Craik & Salthouse, 1992). However,some studies, mainly focused on the behavior of elderly (65 years old and more) ineveryday life, have shown many abilities preserved in old age (Baltes, Kliegl, &Dittman-Kohli, 1988; Schweich, Van der Linden, Bredart, Bruyer, Nelles, & Schills,1992).

Although numerous studies have been conducted in order to highlight which cogni-tive processes may be modified with aging (Welford, 1985), this issue remains amatter of debate. Two types of interpretation are commonly distinguishable: one thatimplies a deficit in general factors and the other that invokes the impairments ofsome specific processes (for review, see Isingrini & Taconnat, 1997).

This work was supported in part by grants from the GDR CNRS—industry ‘Cosmetiques et Parfum’(Grant 222). The authors thank Ms. F. Bouchet and Mr. J. C. Bourzeix for assistance with data collectionand analyses. The authors are grateful to the participants in this study for generously giving their time.Reprint requests should be addressed to Laurence Chaby, Unite de Neurosciences Cognitives et ImagerieCerebrale, CNRS UPR 640, LENA, Hopital de la Salpetriere, 47 bd de l’Hopital, 75651 Paris cedex13, France. Fax: (33-1) 45 86 25 37. E-mail: laurence.chaby@chups.jussieu.fr.

3570278-2626/01 $35.00

Copyright 2001 by Academic PressAll rights of reproduction in any form reserved.

358 CHABY ET AL.

Within the frame of the general-factor theory, age-related deficits are proposed tobe rather distributed throughout the cognitive system (Cerella, 1990). Differences inperformance between elderly and young adults are attributed to age-related changes ina relatively few general factors or mechanisms. One of the most replicated behavioralfindings is the increase of response latency with aging (Wilkinson & Allison, 1989).This increase gets enlarged when task demand increases (Salthouse, 1992). Thus,according to Salthouse (1985), it is considered to reflect a general slowing with aging.Other general factors such as the reduction of working memory capacity, inhibitoryprocesses and attentional resources have been proposed to explain the decline inperformance of elderly in cognitive tasks (Verhaeghen & Salthouse, 1997).

In the context of the specific-process interpretation, aging is considered to affectonly some particular cognitive processes. In agreement with this account, it has beenshown that aging particularly affects processes related to explicit memory such asrecall and recognition (Craik & McDowd, 1987; Craik & Jennings, 1992). In particu-lar, some studies have emphasized the fact that elder people usually report difficultiesin recognizing faces and particularly in putting a name on a familiar face. This latterresult has been corroborated by experimental data showing age-related difficultiesin face recognition tasks (Ferris, Crook, Clark, McCarthy, & Rae, 1980) and moreconsistently in name retrieval tasks (Schweich et al., 1992). Barlett and Fulton (1991)found that old adults were more prone to errors consisting in false face recognitionthan young subjects. While name retrieval difficulties have been extensively investi-gated in elderly, this increase of the rate of false face recognition has not been clearlycharacterized (Searcy, Bartlett, & Memon, 1999).

It is fruitful to study the effect of aging on the processes involved in face recogni-tion, since this function is reported to be affected by aging (Backman, 1991; Barlett &Fulton, 1991) even though face recognition is an everyday task in which humans areexperts, and which does not imply any particular cognitive skill (Diamond & Carey,1986). Characterizing the difficulties of aging adults in terms of the specific or generalimpairment account should be done within the framework of the well-known facerecognition model (Bruce & Young, 1986). This model considers that the recognition,identification, and name retrieval of familiar faces involve a sequence of discretecognitive processes. Face structural encoding constitutes the first process when theface of an individual is encountered. Face recognition is achieved when face recogni-tion units (FRUs), stored in long-term memory, are activated. This activation takesplace whenever the visual characteristics of the encoded faces match the stored repre-sentation of a particular face. Then, FRU activation enables the access to the personidentity node (PIN), which consists of various semantic information, and in turn tothe individual’s name. Elderly subjects may show difficulties at any stage of thismodel and the failure to recognize and/or name a picture of a famous person mayreflect impairment at any specific stage of the face recognition model or instead ata general level.

Most studies dealing with face processing and aging used behavioral measuresonly, such as reaction times (RTs) and accuracy rates. Since these behavioral indicesreflect the final outcome of the cognitive processes, it is difficult to know if theobserved increase in RTs and/or decrease in accuracy rate with aging are related todifficulties occurring at specific stages of processing or generally along the differentstages leading to overt responses. This behavioural approach gives little if any accessto the different stages of cognitive processes.

Event-related potentials (ERPs) can be used as an additional on-line index of theintermediate perceptual and cognitive stages involved in information processing.ERPs consist of a series of brain electrical components, which are time-locked tothe stimulus onset and to the related underlying cognitive processing imposed by

ERPS TO FACIAL INCONGRUITIES IN AGING 359

the task (Renault, Ragot, Lesevre, & Remond, 1982; for a review see Coles, Smid,Scheffers, & Otten, 1995). The effects of psychological factors on the amplitude andlatency of the peaks ERP components have been widely studied, and the correlationof these components with particular cognitive processes have been extensively char-acterized.

In particular, some components have been found to be involved in face processing.Of interest for the present study, N170, N400, and P600 components have beenobserved in tasks using faces. The N170, a face-specific negative component, hasbeen observed to peak in occipito-temporal regions about 150–200 ms poststimulus(Botzel, Schulze, & Stodieck, 1995; George, Evans, Fiori, Davidoff, & Renault, 1996;Bentin, Allison, Puce, Perez, & McCarthy, 1996; Rossion, Gauthier, Tarr, Despland,Bruyer, Linotte, & Crommelinck, 2000; Liu, Higuchi, Marantz, & Kanwisher, 2000).It has been shown that this component reflects the stage of the structural encodingof faces. There is evidence that it is generated by the activation of the fusiform face-responsive areas, which have been reported in many functional imaging studies (Hal-gren, Baudena, Heit, Clarke, & Marinkovic, 1994; Puce, Allison, Spencer, Spencer, &McCarthy, 1997; Kanwisher, McDermott, & Chun, 1997).

Furthermore, numerous studies have explored electrophysiological brain responsesto incongruities between a stimulus (word, picture, or face) and the context in whichit is presented. These studies have largely focused on the so-called N400 component.Kutas and Hillyard (1980) first described the N400 as a negative wave peaking around400 msec, which was enhanced for semantically incongruent sentence-ending wordsrelative to congruent ones (the so-called ‘‘N400 effect’’). Further investigationsshowed that the N400 effect is also observed in paradigms which manipulate therelationship between a stimulus and its immediately preceding context (Kutas, VanPetten, & Besson, 1988) and in nonlinguistic stimuli such as objects (Barrett & Rugg,1990) and faces (Barrett & Rugg, 1989). Indeed, the N400 has been found to bemodulated by priming (Bentin & McCarthy, 1994; Barrett & Rugg, 1989), whichrefers to the facilitatory effect of having previously encountered the same stimulusor a related one on its subsequent recognition. Recently, in priming paradigms usingfaces (Bobes, Valdes-Sosa & Olivares, 1994; Jemel, George, Chaby, Fiori, & Re-nault, 1998; Jemel, George, Olivares, Fiori, & Renault, 1999), a N400-like compo-nent was found to be more important in response to the incongruent than the congru-ent version of a well-known face following the presentation of the uncompleted primeversion of this face. In other words, when an internal representation is preactivatedby a prime, N400 amplitude is small for stimuli related to the preactivated representa-tion and greater for less preactivated or unprimed stimuli. Picton (1988) proposedthat the N400 amplitude varies with the amount of search in memory necessary toobtain the meaning of a stimulus. Finally, the N400 component in response to faceshas been found to peak over infero-temporal leads with possible, at least partly, spe-cific neural generators located in occipito-temporal regions (Olivares, Iglesias, &Bobes, 1999).

In priming paradigms, another late component has also been shown to be modu-lated by face congruity. This widely distributed positive ERP component peaks be-tween 600 and 800 ms (P600) over centro-parietal regions and is comparable to theso-called P3b wave. Its amplitude is enhanced for incongruent, as opposed to congru-ent, faces (McCallum, Farmer, & Pocock, 1984; Juottonen, Revonsuo, & Lang, 1996;Jemel et al., 1998). As the P3b, P600 has been interpreted in different ways. Someauthors considered that it might index the time to evaluate and categorize the stimulus(McCarthy & Donchin, 1981). Others considered the P600 as a manifestation of brainactivity associated with the update of working memory from long-term memory(Donchin & Coles, 1988; Polich & Kok, 1995). These interpretations are not very

360 CHABY ET AL.

different from the hypothesis that P300 may index processes related to responsechoice (Renault, Fiori & Giami, 1998; Fiori, Ragot, & Renault, 1992).

The present research was designed to further investigate how cognitive processesinvolved in the recognition of well-known faces may be affected by normal aging,using a priming paradigm. Behavioral and ERP responses to incongruent relative tocongruent famous faces were recorded in young and middle-aged adults.

There is a sizeable literature dealing with normal aging for subjects beyond 65years, with Alzheimer and Parkinson syndromes, or with a variety of other neurode-generative diseases that affect the aging brain. The growing literature on the effectsof increasing age on various ERP components usually reports longer latencies andsmaller amplitudes of these components in elderly (Fabiani & Friedman, 1995; Kutas,Iragui, & Hillyard, 1994). Moreover, aging is generally associated with less negativityover the anterior scalp region, together with a more pronounced negativity over poste-rior scalp areas (Iragui, Kutas, Mitchiner, & Hillyard, 1993). However, these studiesonly show the result of aging. By contrast, little is known about how and when deficitsrelated to aging begin and very few data exist in the literature concerning subjectsbetween 40 and 65 years old (e.g., Gunter, Jackson & Mulder, 1995; Friedman, Ber-man, & Hamberger, 1993). The omission of a middle-aged group may be due to thedifficulty of recruiting these subjects or to an implicit conviction that age has a lineareffect on performance, reaction time and ERPs. Concentrating on middle-aged sub-jects should provide information regarding the onset of age-related changes in cogni-tive processes in order to gain a comprehensive view of the aging effect on informa-tion processing. In particular, it is more likely to aid the localization of the specificor general factors affected by aging before their impairment becomes more extensive.

METHOD

Subjects

Our sample was constituted by two groups of subjects: middle-aged and young adults. A group of14 right-handed adults (7 males and 7 females) between 18 and 30 years old (mean 5 24.8 6 4.1) wasconstituted. Their recording and analysis constituted the first step of the experiment and have beendescribed in a previous paper (Jemel et al., 1999). The second step of the experiment corresponds tothe present report. A group of 12 right-handed middle-aged subjects (6 males and 6 females), agesbetween 45 and 60 years (mean 5 52.7 6 3.5) was constituted. They were fully informed of the recordingtechnique, methods, and proceedings before agreeing to participate as volunteers in the experiment. Allsubjects had normal or corrected-to-normal vision and were free from neurological, psychiatric, andsignificant other medical past history. The middle-aged subjects were selected to match the young adultgroup on years of full-time education.

Stimuli

Stimuli consisted of 87 photographs of French and international famous faces (males and females ofvarious ages: singers, politicians, actors, sportsmen), presented in front view and with neutral expression(Jemel et al., 1999). These stimuli were carefully selected to contain mostly celebrities that had beenfamous for 10 or more years and that spanned several ages (e.g., Gorbachev, Pompidou, Bjorn Borg,Bette Davis, Paul Newman, Madonna, etc.). Their familiarity was first judged by 10 young adults (Jemelet al., 1999). Ten young and 10 middle-aged judges for the present study undertook this preliminaryfamiliarity task again. In this way, it was verified that all face stimuli were equally familiar to bothgroups of subjects under study (each stimulus was recognized by more than 80% of young as well asmiddle-aged judges).

Each face was digitized and used to construct a prime and two types of test stimuli. Primes portrayeduncompleted famous faces with the eye region masked by a black rectangle. Test stimuli consisted ofthe full-face stimuli, completed with either their original eyes (congruent faces—half of the test faces)or by the eyes of another famous face of the set (incongruent faces—the other half of the test faces).Note that in each case, the eye region was pasted into the prime face, so that any remaining pictorial

ERPS TO FACIAL INCONGRUITIES IN AGING 361

discontinuity was as likely in congruent as in incongruent test faces. Final prime and test stimuli werethen transformed into slides. These were back-projected onto a screen in the recording room using aslide projector with an electromagnetic shutter (constant 3-ms opening delay); the timing of slide presen-tation was controlled by a PC 486 (66 MHz) using a home-made stimulation software.

Procedure

The procedure and instructions were identical to those described in Jemel et al. (1999). Followingelectrode placement, subjects were seated on a comfortable chair in a sound-attenuated room, facing aprojection screen placed at a distance of 1.20 m. Stimuli subtended a vertical visual angle of about 7°and an horizontal visual angle of about 10°. Subjects performed one training block (14 trials presentingfamous faces that did not belong to the experimental set) and eight experimental blocks of 20 trials (10congruent and 10 incongruent trials randomly mixed). In each trial, a prime face was first presented for200 ms and was followed, after a fixed 800-ms interstimulus interval, by a test face also presented for200 ms, which was either congruent or incongruent. The intertrial interval was randomized between3500 and 5000 ms (see Fig. 1a). Subjects were instructed that all test faces may appear somewhatfabricated and that they had to ignore this in order to perform the task correctly, that is in order to decidewhether the test face was congruent (authentic eyes) or incongruent (eyes belonging to another famousperson) by pressing a ‘‘yes’’ or ‘‘no’’ button as fast and as accurately as possible. The ‘‘yes’’ and ‘‘no’’buttons were placed respectively under their right and left index fingers. This position was counterbal-anced across subjects.

Data Acquisition

Percentage of correct responses (% CR) and reaction time (RT). Subjects responses were recordedon-line; correct and incorrect responses were counted separately for congruent and incongruent trials.RT corresponded to the time interval between the test stimulus onset and the subject’s key press. OnlyRTs longer than 200 ms and less than 2000 ms were taken into account (digitised at a rate of 500 Hz).

Two indices of discrimination behavior were computed using Signal Detection Theory (Swets, 1964):discrimination sensitivity (d′) and response bias (Log β). Signal detection theory provides a way toaccount for processes that cannot be simply explained in terms of exogenous stimulus–response relations.These processes include response bias which is affected by the subject’s expectations, motivation, rewardconditions, etc. Incongruent faces were here considered as the signal. Thus, hits were incongruent re-sponses to incongruent trials while false alarms consisted in incongruent responses to congruent trialsand omissions corresponded to congruent responses to incongruent trials. The use of d′ permits an assess-ment of the accuracy of discrimination between congruent and incongruent test faces without contamina-tion from variations in the decision criterion (response bias), the latter being evaluated by Log β. A d′close to 1 or above indicates a high sensitivity to the signal, whereas a d′ close to 0 indicates a responseat chance level.

Event-related potential recording. The electroencephalogram (EEG) was recorded continuously witha 500-Hz sampling rate (bandpass 0.16–160 Hz) from 30 electrodes mounted in an electro-cap andlocated at standard left and right hemispheres and midline positions spanning the scalp surface (Interna-tional 10–20 system; see Fig. 1b). All electrodes were referred to the subject’s nose. Eye movementsand blinks (EOG) were recorded by two bipolar leads. After removal of EEG artifacts, an automaticeye-movement correction program corrected vertical eye movements and blinks (Gratton, Coles, & Don-chin, 1983). The ERP waveforms were then computed by averaging the EEG segments in a time windowbeginning with a 200-ms prestimulus baseline and lasting 1000 ms after the stimulus onset. ERP averageswere obtained separately for each stimulus type (prime faces and congruent and incongruent test faces).Only correct trials were included in these averages. Finally, the data were filtered with a low-pass filter(half-amplitude cutoff, 12 Hz) and visualized as chronograms and scalp potential maps.

Data Analyses

All data were analyzed using Statistica (Statsoft, France, 1998).Behavioral analyses. Behavioral measures (%CR and RTs) were submitted to an analysis of variance

(ANOVA) with Age (young vs. middle-aged) as the between-subjects factor and Congruity (congruentvs. incongruent test faces) as the within-subjects factor. Two t test analyses were used to compare d′and Log β indices of the signal detection theory in young vs. middle-aged groups.

362 CHABY ET AL.

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ERPS TO FACIAL INCONGRUITIES IN AGING 363

ERP analyses. As a preliminary step of ERP analysis, the approach of Jemel et al. (1998, 1999)was reiterated on the middle-aged subjects. Mean ERP amplitudes were measured in successive andoverlapping 40-ms-wide windows from 120 to 500 ms, starting every 20 ms (e.g., 120–160, 140–180,. . . 460–500 ms), over centro-temporo-parieto-occipital electrodes (T3/C3/Cz/C4/T4/T5/P3/Pz/P4/T6/POz). ANOVAs were computed for each time window with Congruity (congruent vs. incongruent testfaces) and Electrodes (T3/C3/Cz/C4/T4/T5/P3/Pz/P4/T6/POz) as factors.

Then, new measurements of the peak amplitude and latency ERP components were performed overspecific leads, per subject and condition, focusing on the time windows of the ERP components understudy. The N170, N400, and P600 peaks were measured, respectively, between 150 and 250, 350 and450, and 500 and 900 ms. The parameters (amplitude, latency, topography) of these ERP componentswere then analyzed in different ANOVAs.

‘‘Priming effect’’ analysis. To assess the N170 scalp topography, we first measured its peak maxi-mum on several electrodes over parieto-temporo-occipital leads. An ANOVA was carried out using Ageas a between-subjects factor and Conditions (prime, congruent test, incongruent test faces) and Electrodes(T3/C3/C4/T4/T5/P3/P4/T6) as within-subjects factors.

The ‘‘Priming effect’’ was then analyzed by an ANOVA with Age as a between-subjects factor andPriming (prime vs. test faces) and Laterality (T5 vs. T6) as within-subjects factors.

‘‘Congruity effect’’ analysis on N170, N400, and P600 components. The congruity effect was ana-lyzed separately on these three ERP components. Three ANOVAs were carried out using Age (youngvs. middle-aged) as a between-subjects factor and additional within-subjects factors:

—for the N170 component: Congruity (congruent vs. incongruent test faces) and Laterality (T5 vs.T6);

—for the N400 component: Congruity (congruent vs. incongruent test faces), Antero-posteriority(frontal:F7/F8, mid-temporal:T3/T4, infero-temporal:T5/T6), and Laterality (left vs. right hemisphere);

—for the P600 component: Congruity (congruent vs. incongruent test faces) and Antero-posteriority(FCz, Cz, CPz, Pz, POz).

Comparisons with greater than 1 degree of freedom were evaluated with adjusted degrees of freedomusing the Greenhouse–Geisser epsilon correction factor (Keselman & Rogan, 1980).

RESULTS

Behavioral Data

Table 1 presents the mean response accuracy rate (%CR) and reaction time (RT)for each group and for congruent and incongruent conditions.

Response accuracy. Middle-aged subjects were globally less accurate than youngadults (67.4% vs. 77.8% CR, respectively; F(1, 24) 5 13.49, p , .001), and theaccuracy rate was higher for congruent relative to incongruent trials (79.3% vs. 65.9%correct, respectively; F(1, 24) 5 25.84, p , .001). In addition, the interaction be-tween Congruity and Age was significant (F(1, 24) 5 9.54, p , .01). It reflectedthat only middle-aged subjects were significantly less accurate in recognizing incon-gruent than congruent test faces (F(1, 11) 5 22.48, p , .001), whereas the differencewas not significant for young adults (F(1, 11) 5 2.18, p . .1)

TABLE 1Percentage of Correct Responses (%) and Reaction Time (ms)

for Congruent and Incongruent Test Faces

Young Middle-aged

Percentage correctCongruent 80.4 (2.01) 78.2 (2.01)Incongruent 75.2 (2.05) 56.7 (3.83)

Reaction time (ms)Congruent 878 (33) 902 (34)Incongruent 893 (32) 952 (42)

Note. Standard errors are in parentheses.

364 CHABY ET AL.

Reaction time. Although RTs were on average longer for middle-aged than youngsubjects (930 ms vs. 890 ms, respectively), this difference was not significant (F(1,24) , 1). Furthermore, RTs were significantly longer for incongruent than congruenttrials (929 ms vs. 891 ms, respectively; F(1, 24) 5 5.47, p , .05). There was nointeraction between Age and Congruity (F(1, 24) 5 1.42, p . .2).

Signal detection analysis. This analysis was used to test whether any responsebias could explain the difference in accuracy rate between the two groups of subjects.

The mean d′ assessing discrimination sensitivity between congruent and incongru-ent faces was .42 6 .05 for middle-aged and .69 6 .06 for young subjects. A t testconfirmed that this discrimination score was significantly lower for middle-aged thanfor young subjects (t 5 3.47, df 5 24, p , .01). By contrast, the mean decisionsubjects criterion (log β) did not show any bias and did not differ significantly be-tween the two groups (2.12 6 .01 vs 2.07 6 .02 for middle-aged and young subjects,respectively, t , 1, df 5 24). This reflects that the low rate of correct incongruentresponses in middle-aged subjects was related to a lower discrimination sensitivityin this age group by comparison to young adults and not to a response bias such asan overall increase of congruent responses in these subjects.

ERP Results

Two types of effects were investigated on ERP data: (i) the ‘‘priming effect’’reflected by the difference in evoked responses to test relative to prime faces, and (ii)the ‘‘congruity effect’’ reflected by the difference in evoked responses to incongruentrelative to congruent test faces.

Priming effect. Figure 2 shows that the N170 component, measured between 150and 250 ms, peaked on occipito-temporal leads, namely T5 and T6, in all conditions(prime, congruent, incongruent faces) and for both groups of subjects. A between-group ANOVA including Conditions and Electrodes (the eight centro-parieto-occipi-tal electrodes) as within-subjects factors confirmed this significant effect of electrodes(F(2.01, 48.32) 5 32.24, epsilon 5 .22, p , .001). Thus N170 was further analysedon T5/T6 (Table 2).

The between-group ANOVA with Priming (prime vs. test faces) and Laterality(T5 vs. T6) as factors showed that N170 amplitude was larger for prime than testfaces (F(1, 24) 5 12.80, p , .05). However, the interaction between Age and Primingalmost reached significance (F(1, 24) 5 2.92, p 5 .06). As can be seen in Fig. 3, the‘‘priming effect’’ (decrease of amplitude from prime to test faces) was particularlyimportant and was significant in young subjects (29.7/26.0 µV; p , .001), whereasit was smaller and not significant in middle-aged subjects ( 212.0/210.8 µV; p . .2).Moreover the amplitude of the N170 in response to prime faces was not significantlydifferent between middle-aged and young subjects (p . .1), whereas it was differentbetween the two age groups in response to test faces (p , .001; see Table 2). Therewas no significant effect of laterality.

Finally, the latency of the N170 peak was delayed for test (216 ms) compared toprime faces (182 ms) in both groups of subjects (F(1, 24) 5 82.1, p , .001). Noother effect on N170 latency approached significance.

Congruity effect. The middle-aged data were first analyzed following the Jemelet al. (1999) approach. This analysis showed that—in successive and overlapping20-ms sliding windows of 40 ms duration from 120 to 500 ms—the difference inmean ERP amplitude for incongruent and congruent faces was never significant (allp . .1) on any of the electrodes (T3/C3/Cz/C4/T4/T5/P3/Pz/P4/T6/POz) in middle-aged subjects. By contrast, the same analysis performed in young adults had shown

ERPS TO FACIAL INCONGRUITIES IN AGING 365

FIG. 2. Scalp distribution of the N170 component and its amplitude as measured over T3, C3, C4,T4, T5, P3, P4, and T6 for prime, congruent, and incongruent test faces in each age group (middle-agedand young subjects).

that the congruity effect was continuously significant from the 180- to 220- to the420- to 460-ms time window on infero-temporal electrodes (all p , .05).

To further characterise the difference between young and middle-aged adults interms of ERP components evoked by congruent and incongruent test faces, we fo-cused on the amplitude, latency, and topography of N170, N400, and P600 compo-nents. In Fig. 4, these components can be seen to be more prominent for incongruentthan congruent test faces in young adults on several electrodes, whereas in middle-

TABLE 2Amplitude (µV) and Latency (ms) of the N170 Component for Prime, Congruent,

and Incongruent Faces, on T5 and T6

Young Middle-aged

Amplitude (µV) Latency (ms) Amplitude (µV) Latency (ms)

T5Prime 29.0(1.2) 178(3) 211.3(1.9) 185(7)Congruent 25.5(1.0) 212(4) 29.9(1.2) 214(5)Incongruent 26.3(1.0) 214(4) 210.0(1.1) 220(5)

T6Prime 210.3(1.5) 180(2) 212.7(2.4) 185(6)Congruent 25.5(1.2) 213(4) 211.5(1.9) 223(5)Incongruent 26.7(1.2) 215(4) 211.7(1.9) 222(4)

Note. Standard errors are in parentheses.

366 CHABY ET AL.

FIG. 3. ERP waveforms recorded over T5 and T6 leads for prime and test (congruent and incongru-ent) faces in middle-aged and young group subjects.

aged subjects this ‘‘congruity effect’’ is not observed in the N170 time window andis small for the N400 and P600 time windows.

Congruity effect on N170. (see Table 2). The analysis of main effects showedsignificant effects of Congruity (F(1, 24) 5 4.62, p , .05) and Age (F(1, 24) 58.10, p , .01). However, although there was no significant interaction between thesetwo factors, post hoc tests revealed that N170 amplitude was significantly larger forincongruent (26.5 µV) than congruent (25.5 µV) test faces in young subjects only(p , .01), whereas there was no such effect in middle-aged subjects (210.8/210.7µV for incongruent/congruent faces respectively, p . .7). Laterality effect (T5/T6)on N170 amplitude for test faces was not significant.

N170 peak latency was delayed for incongruent relative to congruent faces (F(1,24) 5 4.35, p , .05) and on T6 relative to T5 (F(1, 24) 5 5.73, p ,. 05). A significantthree-way interaction between age, congruity, and electrodes (F(1, 24) 5 7.25, p ,.05) indicated that the N170 latency was delayed on T6 relative to T5 only for middle-aged subjects in response to congruent faces (p , .001; see Table 2).

Congruity effect on N400. In order to assess a possible ‘‘antero-posteriority’’modulation of N400 topography with increasing age, congruity effect on N400 ampli-tude and latency was studied on frontal (F7/F8), mid-temporal (T3/T4) and infero-temporal electrodes (T5/T6) in both age groups (Table 3).

Statistical analysis showed an overall increase in N400 amplitude in middle-agedcompared to young subjects (F(1, 24) 5 10.99, p 5 .054). The N400 was also largerfor incongruent than congruent faces (congruity effect; F(1, 24) 5 16.28, p , .001)and over temporal than frontal sites (F(2.00;48.00) 5 8.15, epsilon 5 .68, p , .001).However, there was a two-way interaction between Congruity and Antero-posterior-ity (F(2, 48) 5 4.67, p , .01). Moreover, there was a trend for Age-by-Congruityinteraction (F(1, 24) 5 3.56, p 5 .07). No other interaction approached significance.

ERPS TO FACIAL INCONGRUITIES IN AGING 367

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368 CHABY ET AL.

TABLE 3Amplitude (µV) and Latency (ms) of the N400 Component for Congruent and Incongruent

Faces on Frontal (F7/F8), Mid-temporal (T3/T4), and Infero-temporal (T5/T6)

Young Middle-aged

Congruent Incongruent Congruent Incongruent

FrontalAmplitude(µV) 21.02(0.2) 22.0(0.3) 22.7(0.8) 23.1(0.7)Latency (ms) 362(4) 374(5) 379(8) 396(8)

Mid-temporalAmplitude(µV) 22.1(0.6) 23.3(0.5) 23.7(0.8) 24.2(0.9)Latency (ms) 356(2) 374(5) 373(8) 383(6)

Infero-temporalAmplitude(µV) 21.6(0.4) 24.2(0.4) 25.4(1.3) 26.1(1.6)Latency (ms) 337(5) 359(4) 349(9) 352(10)

Note. Standard errors are in parentheses.

Planned comparison revealed that N400 was maximum over infero-temporal sitesfor all conditions except for congruent faces in young subjects, where N400 wassimilar over all sites. This was reflected by a significant congruity effect in youngsubjects on mid-temporal (F(1, 24) 5 8.38, p , .05) and infero-temporal electrodes(F(1, 24) 5 23.2, p , .001). By contrast, congruity effect never approached signifi-cance in middle-aged subjects (frontal, F(1, 24) 5 1.23, p 5 .27; mid-temporal, F(1,24) 5 1.36, p 5 .25; and infero-temporal electrodes, F(1, 24) 5 1.31, p 5 .26).Moreover, this lack of congruity effect on N400 amplitude in the middle-aged group(in comparison to the young adults) appeared to originate from an enhanced nega-tivity in ERPs to congruent test faces in middle-aged relative to young subjects(F(1, 24) 5 5.87, p , .05), whereas the N400 component to incongruent test faceswas relatively equivalent in both groups (F(1, 24) 5 2.27, p . .1; see Fig. 5a).

Finally, N400 latency was delayed in middle-aged compared to young subjects(F(1, 24) 5 6.92, p , .05), and for incongruent compared to congruent test faces(F(1, 24) 5 15.35, p , .001) as well as over frontal compared to temporal electrodesF(1.2, 28.8) 5 26.5, epsilon 5 .60, p , .001). There was not any significant interac-tion (Table 3).

Congruity effect on late positive component (P600). After the N400 time win-dow, ERPs showed a massive positive deflection for both congruent and incongruentfaces, in both groups (see Fig. 4). This P600 component peaked between 500 and900 ms (mean 5 655 and 753 ms in young and middle-aged subjects, respectively)and had a broad scalp distribution maximum at midline central and parietal sites inboth groups.

A between-group ANOVA with Antero-posteriority (FCz, Cz, CPz, Pz, POz) andCongruity as within-subject factors showed that P600 amplitude was larger overcentro-parietal (Cz, CPz, and Pz) sites (F(1.89, 45.4) 5 6.85, epsilon 5 .47, p ,.01) and for incongruent than congruent faces (F(1, 24) 5 9.34, p , .01). There wasno significant Age effect on P600 amplitude (F(1, 24) 5 1.99, p . .1). Althoughthe interaction between Age and Congruity was not significant (F(1, 24) 5 2.21,p 5 .14), post hoc tests showed that the congruity effect was particularly pronouncedin young subjects (14.2/11.3 µV for incongruent/congruent test faces respectively,p , .01), whereas it was small and not significant in the middle-aged group (10.9/9.8 µV for incongruent/congruent faces, respectively; p . .2) (see Fig. 5b and Table4). The other interactions were not significant.

ERPS TO FACIAL INCONGRUITIES IN AGING 369

FIG. 5. (a) (Left) Mean N400 amplitude over bilateral infero-temporal leads (T5–T6) for congruentand incongruent faces in each age group. ‘‘Congruity effect’’ can be seen for young subjects, whereasit is not significant for middle-aged subjects. There is an age effect on the N400 mean amplitude onlyfor congruent test faces. (Right) The scalp distribution of the grand average ERP difference (incongruentminus congruent faces), in the time range of the N400. (b) (Left) Mean P600 amplitude over centralleads (Cz, CPz, Pz) for congruent and incongruent faces in each age group. ‘‘Congruity effect’’ can beseen in young subjects, whereas it is not significant in middle-aged subjects. (Right) The scalp distributionof the grand average ERP difference (incongruent minus congruent faces), in the time range of the P600.

P600 peak latency was significantly delayed in middle-aged compared to youngsubjects (F(1, 24) 5 9.34, p , .01; Table 4). There was no other significant effecton P600 latency and no interaction.

Finally, one can note that although congruity effect on P600 amplitude was smallerand not significant in middle-aged relative to young subjects, it appeared over a longerperiod of time in the former group (see Fig. 4). This suggests that the P600 may

TABLE 4Amplitude (µV) and Latency (ms) of the P600 Component for Prime, Congruent,

and Incongruent Faces over Midline Sites (FCz, Cz, CPz, Pz, POz)

Young Middle-aged

Amplitude (µV) Latency (ms) Amplitude (µV) Latency (ms)

Congruent 11.3(1.0) 667(24) 9.8(1.4) 763(32)Incongruent 14.1(1.3) 642(23) 10.9(0.9) 742(27)

Note. Standard errors are in parentheses.

370 CHABY ET AL.

display a more important individual variability in middle-aged than young subjects.The examination of individual data showed that in middle-aged, congruity effect onP600 amplitude was clear for two subjects, small for five subjects, and not observedfor the last five subjects. By comparison, in young subjects, congruity effect wasclear for six subjects, small for five subjects, and not observed for three subjects.Additional nonparametric Sign Tests for each age group and for each electrode siteconfirmed that the congruity effect on P600 amplitude was significant in young sub-jects on CPz (incongruent . congruent 5 78.6%, z 5 1.87, p , .05), Pz (incongruent. congruent 5 85.7%, z 5 2.40, p , .05), and POz (incongruent . congruent 592.8%, z 5 2.93, p , .01), whereas it was never significant in middle-aged subjects(all proportions ,66% with all p . .2). In any case, it should also be underlinedthat, since amplitude was measured at the latency of the individual P600 peak ineach subject, the greater individual variability of this peak latency cannot explainthe lack of congruity effect on the amplitudes of the individual P600 peak in middle-aged (relative to young) subjects.

DISCUSSION

The aim of the present study was to investigate how cognitive processes involvedin the processing of incongruity in famous faces may be affected in the early stageof aging, using a visual priming paradigm in middle-aged compared to young adults.In this paradigm, the faces with masked eyes (prime faces) were used to create anexpectancy about which specific pair of eyes should be present in the test face. Ithas been previously shown with young adults (Jemel et al., 1998, 1999) that thedetection of facial incongruity is successfully achieved and that the different cognitiveprocesses involved in this task are reflected by specific negative ERP deflections;therefore, we seek to determine whether this would also hold for middle-aged sub-jects.

The main behavioral finding of the present study was the relative difficulty ofmiddle-aged subjects to discriminate between incongruent and congruent faces.Moreover, whereas ERP in response to prime faces was not affected by aging, behav-ioral and ERP data to congruent and incongruent test faces showed a number ofimportant modulations with age.

Behavioral Data

The middle-aged group made more errors than the young subjects did in detectingincongruent relative to congruent faces. However, this result cannot be explained bya different decision criterion for each group since there was not any group differenceon the response bias (Log β). Thus the lower rate of detection of incongruent facesin middle-aged can be attributed to a reduced ability to discriminate between congru-ent and incongruent test faces. This outcome is consistent with the results of severalstudies that explained age effect by discrimination impairments rather than by theuse of a specific strategy, when the signal detection theory (SDT) analysis was usedto evaluate performance (Kausler & Kleim, 1978; LeBreck & Baron, 1987; Isingrini,Fontaine & Taconnat, 1995). These results can also be interpreted in terms of ‘‘psy-chological distance’’ (Estes, 1994; Dixon, Bub, & Arguin, 1998). In models referringto this notion, objects are represented as points in a multidimensional psychologicalspace. Discrimination difficulties are maximum when objects or faces are closelystored in memory (the smaller the distance between stimuli, the greater their propen-sity to get confused in memory). As the quantity of memorized faces increases with

ERPS TO FACIAL INCONGRUITIES IN AGING 371

aging, their discrimination would become more prone to confusion errors. It can alsobe suggested that, in middle-aged subjects, prime faces preactivated not only specificface representations but also irrelevant ones, thus producing interference effects thatimpeded incongruity processing. This interpretation is consistent with the theoreticalframework (Hasher, Stoltzfus, Rympa, & Zachs, 1991) which proposes an age-relateddecline in the ability to screen irrelevant information out of working memory. Ourresults further show that these age-related increases in confusion errors and/or inter-ference effects are present in the early beginning of aging.

In addition, although RTs were on average longer (60 ms) in the middle-agedsubjects, the increase in RT with aging was not significant in this study. Age-relatedRT increase replicates previous findings showing a general slowness in cognitiveprocesses with aging (Bashore, Osman, & Heffley, 1989), even when no significantage effect was reported (Iragui et al., 1993). In the present study, the lack of signifi-cant RT difference can be explained by the use of middle-aged rather than old sub-jects.

ERP Data

In complement with behavioral measures, ERPs provide continuous record of thebrain activity and give an insight into the different stages of processing involvedby the task. In particular, ERPs provide distinct spatio-temporal information on theprocessing of prime and test faces. The prime face (with masked eyes) was used toactivate an internal representation of the full face in order to facilitate the processingof the test face. In this context, two consequences of priming were expected. First,the consecutive presentation of a prime and the corresponding test face, in a veryshort-time lag, should induce a ‘‘repetition priming effect’’ (Begleiter, Porjesz, &Wang, 1995; George, Jemel, Fiori, & Renault, 1997). Indeed, Brunas, Young, andEllis (1990) showed that even the presentation of a partial face facilitates the subse-quent recognition of the full version of this face (see also, Ellis, Burton, Young, &Flude, 1997). Second, the activation of FRU by the prime face should induce an‘‘associative priming effect’’ reflected by differences in ERPs in response to congru-ent and incongruent test faces (congruity effect).

Both prime and test faces elicited infero-temporal negativities between 170 and220 ms (N170) in the middle-aged and young groups. These results are consistentwith numerous studies that reported face-specific occipito-temporal negativities inthis time range. The N170 has been shown to reflect the stage of structural encodingof faces (Botzel et al., 1995; George et al., 1996; Bentin et al., 1996; Rossion et al.,2000). The lack of age effect on the amplitude and latency of the face-specific N170component in response to prime supports that the prime face was similarly encodedin both groups. In other words, middle-aged subjects did not appear to differ fromyoung adults in terms of the structural encoding of prime faces. By contrast, an ageeffect was observed on N170 in response to test faces. This effect can be explained bya difference in the repetition priming effect between middle-aged and young subjects.Indeed, while N170 amplitude was less prominent for test than prime faces in youngsubjects, it was similar for both prime and test faces in middle-aged subjects. Thus,‘‘priming effect’’ on N170 amplitude was observed in the young adults only. Simi-larly, using familiar faces, Barrett, Rugg, and Perett (1988) found a decreased negativ-ity for repeated relative to nonrepeated faces in temporo-parietal regions within thetime range of 120–160 ms. Such face repetition effect still exists when the photo ismodified between the first and the second presentations (Schweinberger, 1996) orwhen only a part of the face is first presented, as in the present study (Brunas etal., 1990; Ellis et al., 1997). Face repetition effects have been linked to early ERP

372 CHABY ET AL.

modifications, especially when short repetition time lags are used (Barrett et al., 1988;Begleiter et al., 1995). These modifications are in the form of an attenuation of evokedresponses when a stimulus is repeated. The fact that this modulation usually occursfor early ERP components suggests that the repetition priming effect results fromthe activation of specific perceptual representations. The repetition priming effect onERP amplitude would then be the consequence of repeatedly activating the sameperceptual representation, thus facilitating the processing of repeated stimuli. There-fore, the N170 amplitude decrease observed in young adults for test face could bethe consequence of this facilitation originating from the maintenance of a representa-tion of the prime face in short-term visual memory until the presentation of the corre-sponding test face. Conversely the lack of any repetition priming effect in the middle-aged subjects suggests a more rapid decay in memory of visual information relatedto the prime face in these subjects. Indeed, Bentin and Moscovitch (1990) showedthat the larger repetition effects are on ERPs the shorter the lag is since the lastpresentation. These authors suggested that repetition effects on ERPs could reflectthe ‘‘strength’’ of a trace in memory. Other studies (Swick & Knight, 1997; Rugg,Mark, Gilchricht, & Roberts, 1997) compared repetition effects on ERPs in young andold people. They found that repetition effects were generally smaller in magnitude inthe older group, and absent for items repeated at the longest lag. Our data extendthese results to middle-aged subjects.

It has been noted that, in both age groups, the N170 component was delayed fortest compared to prime faces. These results are compatible with previous findings(Deruelle & Neville, 1994; Han, Fan, Chen, & Zhuo, 1997) showing that the identifi-cation of local information elicits posterior negativities of longer latency than theones elicited by the identification of global information. Jemel et al. (1999) suggestedthat the task-relevant information (the attended eyes) in the test faces induced ananalytic strategy while the prime faces were encoded more rapidly and more holisti-cally. The fact that the delay of N170 peak for test relative to prime faces was simi-larly observed in both age groups strongly suggests that some strategy was commonto middle-aged and young subjects.

Regarding associative priming the ‘‘congruity effect’’ was associated to an en-hancement of ERPs in the incongruent relative to the congruent face condition inyoung adults (Bobes et al., 1994; Jemel et al., 1998). By contrast, middle-aged sub-jects did not show such differences of ERP amplitude for congruent and incongruenttest faces. These results concerned the time windows of both the N170 and the N400components. Classically, the congruity effect has been shown on the latter component(the so-called ‘‘N400 effect’’: Kutas & Hillyard, 1980). Therefore we will first dis-cuss the congruity effect relative to the N400.

In previous studies using semantically congruent and incongruent final words insentences, a tendency of the N400 effect to be reduced in old subjects was reported(Harbin, Marsh, & Harvey, 1984; Gunter, Jackson, & Mulder 1995; Iragui, Kutas, &Salmon, 1996). In addition, some authors have found larger N400 effect in childrenthan in adults (Juottonen et al., 1996). However, the reason that this effect was re-duced with advancing age has not been fully investigated. There was no particularmention of whether the reduction of the N400 effect was due to a flattening of theN400 amplitude to incongruent words or to an enhancement of its amplitude forcongruent words, in elderly relative to young subjects. In this study, we found thatN400 amplitude for congruent trials was different between young and middle-agedgroups, whereas it was relatively similar for incongruent trials. In the context of N400paradigms, the prime stimulus is expected to preactivate its internal representation(FRU) and representations that are strongly linked to it in memory. In our study, theprime faces should have preactivated the stored face representation (FRU) or at least

ERPS TO FACIAL INCONGRUITIES IN AGING 373

the representation of the missing portion of the face, thus resulting in reduced N400amplitude for preactivated (congruent faces) as compared to non-preactivated repre-sentations (incongruent faces). This was indeed observed in young subjects, whereN400 amplitude was less prominent for congruent (the preactivated face representa-tion) than incongruent test faces (the unpreactivated ones). However, in the middle-aged group, there was no significant congruity effect on N400 amplitude, and N400amplitude was as important for congruent as for incongruent test faces. The relativeincrease of N400 amplitude for both types of faces suggests that the prime face failedto preactivate relevant face or eye representation. Following Picton (1988) interpreta-tion, the increased N400 amplitude for both types of test faces could be due to asimilar amount of search in memory for both congruent and incongruent faces.

Furthermore, whereas P600 amplitude was larger for incongruent than congruentfaces in young subjects, it was not significantly modulated by congruity processingin the middle-aged group. Actually, one of the classical interpretations of P600 waveis that it indexes the updating of memory (Donchin & Coles, 1988; Polich & Kok,1995). Then it can be suggested that, in young subjects, the content of working mem-ory required less intensive updating in the case of congruent test faces than in thatof incongruent faces, thus explaining the congruity effect on P600 amplitude. Bycontrast, in middle-aged subjects, working memory updating is similar for both con-gruent and incongruent faces, which is consistent with the relative increase of N400amplitude for both types of faces. Thus, the N400 and P600 waves in middle-ageddo not seem modulated by the type of test faces.

Taken together with the absence of repetition priming on N170 amplitude in themiddle-aged, our results on congruity effects suggest different hypotheses concerningdifferences between middle-aged vs. young subjects. The middle-aged might presenta deficit in the activation of full-face representation or might as well be slower atretrieving this information. Indeed, it cannot be excluded that middle-aged subjectscould do as well as the younger ones on test faces if the primes were presented fora longer time. Another hypothesis was that middle-aged subjects might also activatethe full-face representation normally but present a deficit in the maintenance of itstrace in short-term visual memory in the time interval between prime and test faces.On the whole, our results converge to suggest a reduced influence of the prime inmiddle-aged.

Finally, it is now well established in the literature that slowness is a characteristicof aging (Salthouse, 1985; Birren, & Fisher, 1991). Some authors have proposed thata single slowing factor may describe cognitive aging (e.g., Myerson, Hale, Wagstaff,Poon, & Smith, 1990). Few studies have also found slowing around the age of 45–60 years (Iragui et al., 1993; Friedman et al., 1993). However, in accordance withprevious findings (Pfefferbaum, Ford, Wenegrat, Roth, & Kopell, 1984; Looren deJong, Kok, & Van Rooy, 1989; Karayanidis, Andrews, Ward, & McConaghy, 1993;Polich, 1996; Kutas & Iragui, 1998), reaction time did not increase significantly withage, whereas both N400 and P600 peak latencies were delayed in middle-aged com-pared to young subjects. The delay of N400 latency with aging has been sometimesreported (e.g., 80- to 100-ms delay in Harbin et al., 1984; 120-ms delay in Gunter,Jackson, & Mulder, 1992). We speculate that the increase of N400 latency in middle-aged subjects in the present study could be due to the difficulty of the task. Thereis also a general consensus that P300 peak latency increases with aging (see forreview Polich, 1996). In accordance with our results, P300 was found to be delayedin older subjects in several studies (40-ms delay in Ford, Roth, Mohs, Hopkinks, &Kopell, 1979; 55-ms delay in Pfefferbaum, Ford, Roth, & Kopell, 1980; 48-ms delayin Gunter et al., 1992; 98-ms delay in this study). Our results show that such delaysin N400 and P600 latencies can be observed in the early stage of aging, and that this

374 CHABY ET AL.

age effect is not due to stimulus encoding since the N170 latency was not delayedin middle-aged (relative to young) subjects. Results clearly showed that slowingwould not be general and might only concern some stages between the perceptualencoding and the beginning of motor response. This was already suggested by Ver-leger, Neukater, Kompft, and Vieregge (1991), who proposed that the slowing ofmemory process rather than the slowing of encoding might be responsible for P300latency prolongation in aging.

In conclusion, we emphasize that differences of information processing in middle-aged subjects concern only some cognitive processes and do not seem to be fullyexplicated by a general factor. Further studies on the middle-aged should be veryfruitful indices for a better understanding of modifications in cognitive abilities re-lated to aging, in particular for determining which specific factors are important inthe modification of cognitive processes with aging.

REFERENCES

Backman, L. (1991). Recognition memory across adult life-span: The role of prior knowledge. Memoryand Cognition, 19, 63–71.

Baltes, P. B., Kliegl, R., & Dittman-Kohli, F. (1988). On the locus of training gains in research on theplasticity of fluid intelligence in old age. Journal of Educational Psychology, 80, 392–400.

Barlett, J. C., & Fulton, A. (1991). Familiarity and recognition of faces in old age. Memory and Cognition,19, 229–238.

Barrett, S. E., & Rugg, M. D. (1989). Event-related potentials and the semantic matching of faces.Neuropsychologia, 27, 913–922.

Barrett, S. E., & Rugg, M. D. (1990). Event-related potentials and the semantic matching of pictures.Brain and Cognition, 14, 201–212.

Barrett, S. E., Rugg, M. D., & Perrett, D. I. (1988). Event-related potentials and the matching of familiarand unfamiliar faces. Neuropsychologia, 26, 105–117.

Bashore, T. R., Osman, A., & Heffley, E. F. (1989). Mental slowing in elderly persons: A psychophysio-logical analysis. Psychology and Aging, 4, 235–244.

Begleiter, H., Porjesz, B., & Wang, W. (1995). Event-related potentials differentiate priming and recogni-tion to familiar and unfamiliar faces. Journal of Electroencephalography and Clinical Neurophysiol-ogy, 94, 41–49.

Bentin, S., Allison, T., Puce, A., Perez, E., & McCarthy, G. (1996). Electrophysiological studies of faceperception in humans. Journal of Cognitive Neuroscience, 8, 551–565.

Bentin, S., & McCarthy, G. (1994). The effects of immediate stimulus repetition on reaction time andevent-related potentials in tasks of different complexity. Journal of Experimental Psychology:Learning, Memory, and Cognition, 20(1), 130–149.

Bentin, S., & Moscovitch, G. (1990). Neurophysiological indices of implicit memory performance. Bulle-tin of Psychonomic Society, 28, 346–352.

Birren, J. E., & Fisher, L. M. (1991). Aging and slowing of behavior: Consequences for cognition andsurvival. Nebraska Symposium on Motivation, 39, 1–37.

Bobes, M. A., Valdes-Sosa, M., & Olivares, E. (1994). An ERP study of expectancy violation in faceperception. Brain and Cognition, 26, 1–22.

Botzel, K., Schulze, S., & Stodieck, S. R. G. (1995). Scalp topography and analysis of intracranialsources of face-evoked potentials. Experimental Brain Research, 104, 134–143.

Bruce. V., & Young, A. W. (1986). Understanding face recognition. British Journal of Psychology, 77,305–327.

Brunas, J., Young, A. W., & Ellis, A. W. (1990). Evidence for part to whole completion. British Journalof Psychology, 81, 43–56.

Cerella, J. (1990). Aging and information-processing rate. In J. E. Birren & K. W. Shaie (Eds.), Handbookof the psychology of aging. San Diego: Academic Press.

Coles, M. G. H., Smid, H. G. O. M., Scheffers, M. K., & Otten, L. J. (1995). Mental chronometry andthe study of human information processing. In M. D. Rugg & M. G. H. Coles (Eds.), Electrophysiol-ogy of mind. New York: Oxford University Press.

ERPS TO FACIAL INCONGRUITIES IN AGING 375

Craik, F. I. M., & Jennings, J. M. (1992). Human memory. In F. M. I. Craik & T. A. Salthouse (Eds.),The handbook of aging and cognition. Hillsdale, NJ: Erlbaum.

Craik, F. I. M., & McDowd, J. M. (1987). Age differences in recall and recognition. Journal of Experi-mental Psychology: Learning, Memory, and Cognition, 13, 671–684.

Craik, F. I. M., & Salthouse, T. A. (1992). The handbook of aging and cognition. Hillsdale, NJ: Erlbaum.

Deruelle, C., & Neville, H. J. (1994). Different neural systems are activated during global and localvisual processing: A RT and ERP study. Abstract Book of Cognitive Neurosciences Society, 53.

Diamond, R., & Carey, S. (1986). Why faces are and are not special: An effect of expertise. Journalof Experimental Psychology: General, 115, 107–117.

Dixon, M. J., Bub, D. N., & Arguin, M. (1998). Semantic and visual determinants of face recognitionin Prosopagnosic patient. Journal of Cognitive Neuroscience, 10(3), 362–376.

Donchin, E., & Coles, M. G. H. (1988). Is the P300 component a manifestation of context updating?Behavioural and Brain Sciences, 11, 357–374.

Ellis, A. W., Burton, A. M., Young, A. W., & Flude, B. M. (1997). Repetition priming between partsand wholes: Tests of a computational model of familiar face recognition. British Journal of Psychol-ogy, 88, 579–608.

Estes, W. K. (1994). Classification and cognition. New York: Oxford University Press.

Fabiani, M., & Friedman, D. (1995). Changes in brain activity patterns in aging: The novelty oddball.Psychophysiology, 32(6), 579–594.

Ferris, S. H., Crook, T., Clark, E., McCarthy, M., & Rae, D. (1980). Facial recognition memory deficitsin normal aging and senile dementia. Journal of Gerontology, 35, 707–714.

Fiori, N., Ragot, R., & Renault, B. (1992). Effect of target position on the sequential organisation ofprocessing stages. Biological Psychology, 33, 157–171.

Ford, J. M., Roth, W. T., Mohs, R. C., Hopkins, W. F., & Kopell, B. S. (1979). Event-related potentialsrecorded from young and old adults during a memory retrieval task. Journal of Electroencephalogra-phy and Clinical Neurophysiology, 47, 450–459.

Friedman, D., Berman, S., & Hamberger, M. (1993). Recognition memory and ERPs: Age relatedchanges in young, middle-aged, and elderly adults. Journal of Psychophysiology, 7, 181–201.

George, N., Evans, J., Fiori, N., Davidoff, J., & Renault, B. (1996). Brain events related to normal andmoderately scrambled faces. Cognitive Brain Research, 4, 65–76.

George, N., Jemel, B., Fiori, N., & Renault, B. (1997). Face and shape repetition effects in humans: Aspatio-temporal ERP study. Neuroreport, 8(6), 1417–1423.

Gratton, G., Coles, M. G. H., & Donchin, E. (1983). A new method of off-line removal of ocular artefact.Electroencephalography and Clinical Neurophysiology, 55, 468–484.

Gunter, T. C., Jackson, J. L., & Mulder, G. (1992). An electrophysiological study of semantic processingin young and middle-aged academics. Psychophysiology, 29(1), 38–54.

Gunter, T. C., Jackson, J. L., & Mulder, G. (1995). Language, memory, and aging: An electrophysiologi-cal exploration of the N400 during reading of memory-demanding sentences. Psychophysiology,32, 215–229.

Halgren, E., Baudena, P., Heit, G., Clarke, M., & Marinkovic, K. (1994). Spatio-temporal stages in faceand word processing. 1. Depth-recorded potentials in the human occipital, temporal and parietallobes. Journal of Physiology, 88, 1–50.

Han, S., Fan, S., Chen, L., & Zhuo, Y. (1997). On the different processing of wholes and parts: Apsychophysiological analysis. Journal of Cognitive Neuroscience, 9, 687–698.

Harbin, T. J., Marsh, G. R., & Harvey, M. T. (1984). Differences in the late components of the event-related potential due to age and to semantic and non-semantic tasks. Journal of Electroencephalog-raphy and Clinical Neurophysiology, 59, 489–496.

Hasher, L., Stoltzfus, E. R., Rympa, B., & Zacks, R. T. (1991). Age and inhibition. Journal of Experimen-tal Psychology, 17(1), 163–169.

Iragui, V. J., Kutas, M., Mitchiner, R., & Hillyard, S. A. (1993). Effects of aging on event-relatedpotentials and reaction times in an auditory oddball task. Psychophysiology, 30, 10–22.

Iragui, V. J., Kutas, M., & Salmon, D. P. (1996). Event-related potentials during semantic categorizationin normal aging and senile dementia of the Alzheimer’s type. Journal of Electroencephalographyand Clinical Neurophysiology, 100, 392–406.

Isingrini, M., Fontaine, R., & Taconnat, L. (1995). Aging and encoding in memory: False alarms anddecision criteria in a word-pair recognition task. The International Journal of Aging and HumanDevelopment, 41, 77–86.

376 CHABY ET AL.

Isingrini, M., & Taconnat, L. (1997). Aspect du vieillissement normal de la memoire. Psychologie Fran-caise, 42(4), 319–331.

Jemel, B., George, N., Chaby, L., Fiori, N., & Renault, B. (1998). Incongruite semantique et incongruitefaciale. In Y. Christen, L. Collet, & M.-T. Droy-Lefaix (Eds.), Rencontres IPSEN en ORL, Tome2 (pp. 101–114). Paris: Irvin.

Jemel, B., George, N., Olivares, E., Fiori, N., & Renault, B. (1999). Event-related potentials to structuralfamiliar face incongruity processing. Psychophysiology, 36(4), 437–452.

Juottonen, K., Revonsuo, A., & Lang, H. (1996). Dissimilar age influences on two waveforms (LPCand N400) reflecting semantic context effect. Cognitive Brain Research, 4, 99–107.

Kanwisher, N., McDermott, J., & Chun, M. M. (1997). The fusiform face area: A module in humanextrastriate cortex specialized for face perception. Journal of Neuroscience, 17(11), 4302–4311.

Karayanidis, F., Andrews, S, Ward, P. B., & McConaghy, N. (1993). Event-related potentials and repeti-tion priming in young, middle-aged and elderly normal subjects. Cognitive Brain Research, 1, 123–134.

Kausler, D. H., & Kleim, D. M. (1978). Age difference in processing relevant versus irrelevant stimuliin multiple item recognition learning. Journal of Gerontology, 33, 87–93.

Keselman, H. J., & Rogan, J. C. (1980). Repeated measures F tests and psychophysiological research:Controlling the number of false positives. Psychophysiology, 17(5), 499–503.

Kutas, M., & Hillyard, S. A. (1980). Reading senseless sentences: Brain potentials reflect semanticincongruity. Science, 207, 203–205.

Kutas, M., & Iragui, V. (1998). The N400 in a semantic categorization task across 6 decades. Electroen-cephalography and Clinical Neurophysiology, 109(5), 456–471.

Kutas, M., Iragui, V., & Hillyard, S. A. (1994). Effects of aging on event-related brain potentials (ERPs)in a visual detection task. Electroencephalography and Clinical Neurophysiology, 92(2), 126–139.

Kutas, M., Van Petten, C., & Besson, M. (1988). Event-related potential asymmetries during the readingof sentences. Electroencephalography and Clinical Neurophysiology, 69(3), 218–233.

Le Breck, D., & Baron, A. (1987). Age and practice effects in continuous recognition memory. Journalof Gerontology, 42, 89–91.

Looren de Jong, H., Kok, A., & Van Rooy, J. C. G. M. (1989). Stimulus probability and motor responsein young and old adults: An ERP study. Biological Psychology, 29, 125–148.

Liu, J., Higuchi, M., Marantz, A., & Kanwisher, N. 2000. The selectivity of the occipitotemporal M170for faces. NeuroReport, 11(27), 337–341.

McCallum, W., Farmer, S., & Pocock, P. (1984). The effects of physical and semantic incongruities onauditory event-related potentials. Journal of Electroencephalography and Clinical Neurophysiology,59, 477–488.

McCarthy, G., & Donchin, E. (1981). A metric for thought: A comparison of P300 latency and reactiontime. Science, 211, 77–80.

Myerson, J., Hale, S., Wagstaff, D., Poon, L. W., & Smith, G. A. (1990). The information-loss model:A mathematical theory of age-related cognitive slowing. Psychological Review, 97(4), 475–487.

Olivares, E. I., Iglesias, J., & Bobes, A. M. (1999). Searching for face-specific long latency ERPs: Atopographic study of effects associated with mismatching features. Brain Research. Cognitive BrainResearch, 7(3), 343–356.

Pfefferbaum, A., Ford, J. M., Roth, W. T., & Kopell, B. S. (1980). Age differences in P3-reaction timeassociations. Electroencephalography and Clinical Neurophysiology, 49, 257–265.

Pfefferbaum, A., Ford, J. M., Wenegrat, B. G., Roth, W. T., & Kopell, B. S. (1984). Clinical applicationof the P3 component of the ERP I: Normal aging. Electroencephalography and Clinical Neurophysi-ology, 59, 85–103.

Picton, T. W. (1988). The endogenous evoked potentials. In E. Basar (Ed.), Dynamics of sensory ofsensory and cognitive processes in the brain. New York: Springer-Verlag.

Polich, J. (1996). Meta-analysis of P300 in normative aging studies. Psychophysiology, 33, 334–353.

Polich, J., & Kok, A. (1995). Cognitive and biological determinants of P300: An integrative review.Biological Psychology, 41, 103–146.

Puce, A., Allison, T., Spencer, S. S., Spencer, D. D., & McCarthy, G. (1997). Comparison of corticalactivation evoked by faces measured by intracranial field potentials and functional MRI: Two-casestudies. Human Brain Mapping, 5, 298–305.

Renault, B., Fiori, N., & Giami, S. (1988). Latencies of event related potentials as a tool for studyingmotor processing organization. Biological Psychology, 26(1–3), 217–230.

ERPS TO FACIAL INCONGRUITIES IN AGING 377

Renault, B., Ragot, R., Lesevre, N., & Remond, A. (1982). Onset and offset of brain events as indicesof mental chronometry. Science, 215, 1412–1415.

Rossion, B., Gauthier, I., Tarr, M. J., Despland, P., Bruyer, R., Linotte, S., & Crommelinck, M. (2000).The N170 occipito-temporal component is delayed and enhanced to inverted faces but not invertedobjects: An electrophysiological account of face-specific processes in the human brain. NeuroRe-port, 11(1), 69–74.

Rugg, M. D., Mark, R. E., Gilchrist, J., & Roberts, R. C. (1997). ERP repetition effects in indirect anddirect tasks: Effects of age and interitem lag. Psychophysiology, 34(5), 572–586.

Salthouse, T. A. (1985). A theory of cognitive aging. Amsterdam: North Holland.

Salthouse, T. A. (1992). Why do adult age differences increase with task complexity? DevelopmentalPsychology, 28, 905–918.

Schweich, M., Van der Linden, M., Bredart, S., Bruyer, R., Nelles, B., & Schills, J. P. (1992). Dailylife difficulties in person recognition by young and elderly subjects. Applied Cognitive Psychology,6, 161–172.

Schweinberger, S. R. (1996). How Gorbachev primed Yeltsin: Analyses of associative priming in personrecognition by means of reaction times and event-related brain potentials. Journal of ExperimentalPsychology: Learning, Memory, and Cognition, 22, 1383–1407.

Searcy, J. H., Bartlett, J. C., & Memon, A. (1999). Age differences in accuracy and choosing in eyewit-ness identification and face recognition. Memory and Cognition, 27(3), 538–552.

Spirduso, W. W. (1995). Physical dimensions of aging. Texas: Human Kinetics.Swets, J. A. (1964). Signal detection and recognition by humans observers. New York: Wiley.

Swick, D., & Knight, R. T. (1997). Event-related potentials differentiate the effects of aging on wordand nonword repetition in explicit and implicit memory tasks. Journal of Experimental Psychology:Learning, Memory, and Cognition, 23(1), 123–142.

Verhaeghen, P., & Salthouse, T. A. (1997). Meta-analyses of age-cognition relations in adulthood: Esti-mates of linear and nonlinear age effects and structural models. Psychological Bulletin, 122(3),231–249.

Verleger, R., Neukater, W., Kompf, D., & Vieregge, P. (1991). On the reasons for the delay of P3 latencyin healthy elderly subjects. Electroencephalography and Clinical Neurophysiology, 79(6), 488–502.

Welford, A. T. (1985). Changes of Performances with age: An overview. In N. Charness (Ed.), Agingand human performance. Chichester: Wiley.

Wilkinson, R. T., & Allisson, S. (1989). Age and simple reaction time: Decade differences for 5,325subjects. Journal of Gerontology: Psychological Sciences, 44, 29–35.