Measurements

FER Task. To assess the FER ability, we designed the FER Task. The stimuli

were taken from the database of the East Asian face expression stimuli (Tu et al.,

2018). The database consisted of 628 photos, including seven basic face emotion

expression categories (happiness, sadness, anger, surprise, fear, disgust, and neutral).

Forty-eight young (age range: 18–51 years; 23/25 males/females) and 42 older (age

range: 58–86 years; 21/21 males/females) adults were included in this database.

However, among these, 29 young individuals (15 males, 14 females) from Cheng,

Chen, Chan, Su, and Tseng’s (2013) database were actors; besides, the background

and brightness of their photos were different from those of the Tu et al. (2018)

database. Thus, we excluded these photos and others that were incomplete or

inappropriate. Finally, 406 photos (58 individuals with seven expressions each) were

selected as the emotion stimuli in our pilot study. All selected individuals are

Taiwanese and lived around Taipei; none of them are actors. They were instructed to

move their facial muscles to produce prototypical expressions based on the Facial

Action Coding System (Ekman and Friesen, 1978; Ekman, Friesen, & Hager, 2002).

All photographs were colored, front-view head shots on white backgrounds.

Our Task used the multiple forced-choice rating, and the 5-point Likert scale to

measure the accuracy and the intensity of each photo (ranging from 1: very slightly or

not at all to 5: extremely), respectively. The response options appeared in black on a

white background below the faces and were always presented in the same order. For

reducing the practice effect, the presentation order of emotional faces was identical

for each participant; besides, the lists were pseudo-randomized with the constraint

that no more than two faces of the same face presenter or the same facial expression

were repeated in a row. Stimulus presentation and response collection (accuracy and

intensity) were controlled using E-Prime (Schneider, Eschman, & Zuccolotto, 2002)

and were displayed on a 14-inch notebook.

During the FER Task, participants saw one face at a time. They were asked to

indicate the emotion of the face as soon as possible by pressing one of the response

buttons on a button box. The photos and the response options (emotional category)

were always presented for reducing the need of memory. After participants choose the

emotion of the photo, they were asked to rate the intensity of the selected emotion

presented in the photo. The instruction was, taking a happy expression for example,

“how intense does this image look in terms of happiness?”).

A pilot test was designed to establish the applicability of the tools. An additional

20 younger adults and 20 healthy older adults were recruited to rate the accuracy and

the intensity of the 406 emotional faces. The procedure and design were the same as

in the normal experiment. After the pilot test, we found that disgust was highly

mislabeled as anger thus showed lower accuracy. This pattern was similar to the

previous results by Widen, Russell, and Brooks (2004); besides, they indicated that

the categories of anger and disgust are overlapping, and the prototypical ‘disgust’ face

may tend to be seen as a subtype of anger. As stated above, disgust was removed from

our emotion category. In addition, we found that fear was highly mislabeled as

surprise. However, fear has been reported to be the most difficult emotion to decode

(Derntl et al., 2008; Wells et al., 2016). It is worthy for us to retain fear rather than

surprise in our final emotion categories to examine the performances in both healthy

individuals and in patients. Therefore, we removed surprise from category. Moreover,

the photos from 21 individuals were also screened out because the accuracy of these

photos was lower than 50% of the overall score. One hundred and fifty-five pictures,

in which there are 9 old female and male, 6 young female, and 7 young male photos

for each of the 5 emotion types and neutral, were finally selected as stimulating

materials for the FER Task. The age of older pictures ranges from 55-80 years old; the

age of younger pictures ranges from 20-30 years old.

Neuropsychological assessment. All the younger, HC, SCD, MCI, and AD

participants underwent a neuropsychological assessment conducted by a

neuropsychologist or a project coordinator. Mini mental status examination (MMSE)

and screening for cognitive impairments were performed initially. To rule out the possibility that the intellectual ability might interfere with participants’ FER ability,

participants’ intellectual quotient (IQ) performances on the Wechsler Adult

Intelligence Scale-Third Edition (WAIS-III) or WAIS-IV were collected through the

record of their recent neuropsychological examination. The Logical Memory Subtests

I and II of the Wechsler Memory Scale-III (WMS-III) (Hua et al., 2005; Petersen &

Morris, 2005) were performed to obtain the scores for episodic memory. For those

who did not have previous record, full-scale IQ estimated by performances on the

Similarities, the Arithmetic, the Matrix Reasoning, and the Digit Symbol Substitution

subtests from the WAIS-III (Chen, Hua, Zhu, & Chen, 2008) and the Logical Memory

Subtests I and II of the WMS-III were conducted by the project coordinator. To

control for perceptually based face processing deficits, the Short Form Benton Facial

Recognition Test (BFRT; Benton et al., 1994) was administrated. All older

participants underwent the Taiwan Geriatric Depression Scale (TGDS) (Liao et al.,

2004) test for emotional status evaluation. For patients with SCD, MCI, and AD, a

neuropsychologist also interviewed their informant to complete the CDR.