Age-related changes in amplitude, latency and specialization of ERP responses to faces and watches

Age-related similarities and differences in cognitive and neural processing revealed by task-related microstate analysis

We explored neural processing differences associated with aging across four cognitive functions. In addition to ERP analysis, we included task-related microstate analyses, which identified stable states of neural activity across the scalp over time, to explore whole-head neural activation differences. Younger and older adults (YA, OA) completed face perception (N170), word-pair judgment (N400), visual oddball (P3), and flanker (ERN) tasks. Age-related effects differed across tasks. Despite age-related delayed latencies, N170 ERP and microstate analyses indicated no age-related differences in amplitudes or microstates. However, age-related condition differences were found for P3 and N00 amplitudes and scalp topographies: smaller condition differences were found for in OAs as well as broader centroparietal scalp distributions. Age group comparisons for the ERN revealed similar focal frontocentral activation loci, but differential activation patterns. Our findings of differential age effects across tasks are most consistent with the STAC-r framework which proposes that age-related effects differ depending on the resources available and the kinds of processing and cognitive load required of various tasks.

Effects of aging on face processing: An ERP study of the own-age bias with neutral and emotional faces

Older adults systematically show an enhanced N170 amplitude during the visualization of facial expressions of emotion. The present study aimed to replicate this finding, further investigating if this effect is specific to facial stimuli, present in other neural correlates of face processing, and modulated by own-age faces. To this purpose, younger (n = 25; M_age = 28.36), middle-aged (n = 23; M_age = 48.74), and older adults (n = 25; M_age = 67.36) performed two face/emotion identification tasks during an EEG recording. The results showed that groups did not differ regarding P100 amplitude, but older adults had increased N170 amplitude for both facial and non-facial stimuli. The event-related potentials analysed were not modulated by an own-age bias, but older faces elicited larger N170 in the Emotion Identification Task for all groups. This increased amplitude may reflect a higher ambiguity of older faces due to age-related changes in their physical features, which may elicit higher neural resources to decode. Regarding P250, older faces elicited decreased amplitudes than younger faces, which may reflect a reduced processing of the emotional content of older faces. This interpretation is consistent with the lower accuracy obtained for this category of stimuli across groups. These results have important social implications and suggest that aging may hamper the neural processing of facial expressions of emotion, especially for own-age peers.

Healthy aging impairs face discrimination ability

Face images enable individual identities to be discriminated from one another. We aimed to quantify age-related changes in different aspects of face identity discrimination. Face discrimination sensitivity was measured with a memory-free “odd-one-out” task. Five age groups (N = 15) of healthy adults with normal vision were tested: 20, 50-59, 60-69, 70-79, and 80-89. Sensitivity was measured for full-face images (all features visible), external features (head-shape, hairline), internal features (nose, mouth, eyes, and eyebrows) and closed-contour shapes (control object). Sensitivity to full-faces continuously declined by approximately 13% per decade, after 50 years of age. When age-related differences in visual acuity were controlled, the effect of age on face discrimination sensitivity remained. Sensitivity to face features also deteriorated with age. Although the effect for external features was similar to full-faces, the rate of decline was considerably steeper (approximately 3.7 times) for internal, relative to external, features. In contrast, there was no effect of age on sensitivity to shapes. All age groups demonstrated the same overall pattern of sensitivity to different types of face information. Healthy aging was associated with a continuous decline in sensitivity to both full-faces and face features, although encoding of internal features was disproportionately impaired. This age-related deficit was independent of differences in low-level vision. That sensitivity to shapes was unaffected by age suggests these results cannot be explained by general cognitive decline or lower-level visual deficits. Instead, healthy aging is associated with a specific decline in the mechanisms that underlie face discrimination.

The effect of age on the early stage of face perception in depressed patients: An ERP study

The aim of the present study was to investigate the age effect on face perceptual processing in MDD patients by analyzing the N170 component in response to faces and objects presented in upright and inverted conditions. For controls, although the N170 amplitude, overall, did not differ between young and middle-aged participants, the size of N170 inversion effect was larger for young than for middle-aged controls, but the N170 face effect was not influenced by age. For young participants, MDD patients showed N170 amplitude similar to controls and neither the N170 face effect nor the N170 inversion effect were influenced by depression. For middle-aged participants, MDD patients revealed larger N170 than did controls, and both the size of N170 inversion effect and the N170 face effect were larger for MDD patients than controls. These data indicate that, at least at the early stage of face perception, there is altered face perception in middle-aged but not in young MDD patients. This research could provide new evidence for clinical assessment of cognitive function in MDD patients.

Effect of Cognitive Control on Age-Related Positivity Effects in Attentional Processing - Evidence From an Event-Related Brain Potential Study

Studies investigating age-related positivity effects during facial emotion processing have yielded contradictory results. The present study aimed to elucidate the mechanisms of cognitive control during attentional processing of emotional faces among older adults. We used go/no-go detection tasks combined with event-related potentials and source localization to examine the effects of response inhibition on age-related positivity effects. Data were obtained from 23 older and 23 younger healthy participants. Behavioral results showed that the discriminability index (d') of older adults on fear trials was significantly greater than that of younger adults [t(44)=2.37, p=0.024, Cohen's d=0.70], whereas an opposite pattern was found in happy trials [t(44)=2.56, p=0.014, Cohen's d=0.75]. The electroencephalography results on the amplitude of the N170 at the left electrode positions showed that the fear-neutral face pairs were larger than the happy-neutral ones for the younger adults [t(22)=2.32, p=0.030, Cohen's d=0.48]; the older group's right hemisphere presented similar tendency, although the results were not statistically significant [t(22)=1.97, p=0.061, Cohen's d=0.41]. Further, the brain activity of the two hemispheres in older adults showed asymmetrical decrement. Our study demonstrated that the age-related "positivity effect" was not observed owing to the depletion of available cognitive resources at the early attentional stage. Moreover, bilateral activation of the two hemispheres may be important signals of normal aging.

Behavioral inhibition and dual mechanisms of anxiety risk: Disentangling neural correlates of proactive and reactive control

Background:

Behavioral inhibition (BI) is a temperament style characterized by heightened reactivity and negative affect in response to novel people and situations, and it predicts anxiety problems later in life. However, not all BI children develop anxiety problems, and mounting evidence suggests that how one manages their cognitive resources (cognitive control) influences anxiety risk. The present study tests whether more (proactive control) or less (reactive control) planful cognitive strategies moderate relations between early BI and later anxiety.

Methods:

Participants included 112 adolescents (55% female; M_age = 15.4 years) whose temperament was assessed during toddlerhood. In adolescence, participants completed an AX Continuous Performance Test while electroencephalography was recorded to disentangle neural activity related to proactive (cue-locked P3b) and reactive (probe-locked N2) control.

Results:

Greater BI was associated with greater total anxiety scores only among adolescents with smaller ΔP3bs and larger ΔN2s—a pattern consistent with decreased reliance on proactive strategies and increased reliance on reactive strategies. Additionally, a larger ΔP3b was associated with greater total anxiety scores; however, this effect was largely explained by the fact that females tended to have larger ΔP3bs and greater anxiety than males.

Conclusions:

Early BI relates to risk for later anxiety specifically among adolescents who rely less on proactive strategies and more on reactive control strategies. Thus, cognitive control strategy moderates the association between developmental context (i.e., temperament) and later anxiety. The present study is the first to characterize how proactive and reactive control uniquely relate to pathways toward anxiety risk.

The ERP correlates of self-knowledge in ageing

Self-knowledge is a type of personal semantic knowledge that concerns one's self-image and personal identity. It has most often been operationalized as the summary of one's personality traits ("I am a stubborn person"). Interestingly, recent studies have revealed that the neural correlates of self-knowledge can be dissociated from those of general semantic and episodic memory in young adults. However, studies of "dedifferentiation" or loss of distinctiveness of neural representations in ageing suggest that the neural correlates of self-knowledge might be less distinct from those of semantic and episodic memory in older adults. We investigated this question in an event-related potential (ERP) study with 28 young and 26 older adults while they categorised personality traits for their self-relevance (self-knowledge conditions), and their relevance to certain groups of people (general semantic condition). Participants then performed a recognition test for previously seen traits (episodic condition). The amplitude of the late positive component (LPC), associated with episodic recollection processes, differentiated the self-knowledge, general semantic, and episodic conditions in young adults, but not in older adults. However, in older adults, participants with higher composite episodic memory scores had more differentiated LPC amplitudes across experimental conditions. Moreover, consistent with the fact that age-related neural dedifferentiation may be material and region specific, in both age groups some differences between memory types were observed for the N400 component, associated with semantic processing. Taken together, these findings suggest that declarative memory subtypes are less distinct in ageing, but that the amount of differentiation varies with episodic memory function.

Measurement of individual differences in face-identity processing abilities in older adults

BACKGROUND

Face-identity processing declines with age. Few studies have examined whether face-identity processing abilities can be measured independently from general cognitive abilities in older adults (OA). This question has practical implications for the assessment of face-identity processing abilities in OA and theoretical implications for the notion of face processing as a specific ability. The present study examined the specificity of face memory and face matching abilities in OA aged 50 + .

METHODS

Performance of younger adults (YA) and OA was measured on face tasks: Cambridge Face Memory Task (CFMT), the Glasgow Face Matching Task (GFMT), holistic processing; and tasks of general cognition: fluid intelligence, selective attention, and mental rotation. Data were analyzed using multiple regression models encompassing (i) the CFMT/GFMT and measures of general cognition; and (ii) all face processing tasks.

RESULTS

Across the two age groups, models encompassing all face tasks were significant and accounted for more variance in the data than models encompassing the CFMT/GFMT and measures of general cognition. General cognitive abilities accounted for 17% of variance for the GFMT (p < 0.01) and 3% for the CFMT (p > 0.05).

DISCUSSION

Our results suggest that face memory can be measured independently from general cognition using the CFMT in OA. Implications for the notion of a general face processing factor across the adult lifespan are discussed.

Different measures of holistic face processing tap into distinct but partially overlapping mechanisms

Holistic processing, which includes the integration of facial features and analysis of their relations to one another, is a hallmark of what makes faces 'special'. Various experimental paradigms purport to measure holistic processing but these have often produced inconsistent results. This has led researchers to question the nature and structure of the mechanism(s) underlying holistic processing. Using an individual differences approach, researchers have examined relations between various measures of holistic processing in an attempt to resolve these questions. In keeping with this, we examined relationships between four commonly used measures of holistic face processing in a large group of participants (N = 223): (1) The Face Inversion Effect, (2) the Part Whole Effect (PWE), (3) the Composite Face Effect, and (4) the Configural Featural Detection Task (CFDT). Several novel methodological and analytical elements were introduced, including the use of factor analysis and the inclusion of control conditions to confirm the face specificity of all of the effects measured. The four indexes of holistic processing derived from each measure loaded onto two factors, one encompassing the PWE and the CFDT, and one encompassing the CE. The 16 conditions tested across the four tasks loaded onto four factors, each factor corresponding to a different measure. These results, together with those of other studies, suggest that holistic processing is a multifaceted construct and that different measures tap into distinct but partially overlapping elements of it.

Earlier than previously thought: Yawn contagion in preschool children

Yawning is a primitive and stereotyped motor action involving orofacial, laryngeal, pharyngeal, thoracic and abdominal muscles. Contagious yawning, an involuntarily action induced by viewing or listening to others' yawns, has been demonstrated in human and several non-human species. Previous studies with humans showed that infants and preschool children, socially separated during video experiments, were not infected by others' yawns. Here, we tested the occurrence of yawn contagion in 129 preschool children (ranging from 2.5 to 5.5 years) belonging to five different classes by video recording them in their classrooms during the ordinary school activities. As it occurs in adult humans, children of all ages were infected by others' yawns within the 2 min after the perception of the stimulus. The yawn contagion occurred earlier than previously thought. For children, it appears that the natural social setting is more conducive to yawn contagion than the inherently artificial experimental approach. Moreover, children's gender did not affect the level of contagious yawning. The neural, emotional and behavioural traits of preschool children are probably not sufficiently mature to express variability between boys and girls; nevertheless, children appeared to be already well equipped with the 'neural toolkit' necessary for expressing yawn contagion.

Do perceptual expertise and implicit racial bias predict early face-sensitive ERP responses?

Studies examining the visual perception of face race have revealed mixed findings regarding the presence or direction of effects on early face-sensitive event-related potential (ERP) components. Few studies have examined how early ERP components are influenced by individual differences in bottom-up and top-down processes involved in face perception, and how such factors might interact to influence early face-sensitive ERP components has yet to be investigated. Thus, the current study examined whether P100, N170, and P200 responses can be predicted by individual differences in own- and other-race face recognition, implicit racial bias, and their interaction. Race effects were observed in the P100, N170, and P200 responses. Other-race face recognition, implicit racial biases, and their interaction explained a significant amount of unique variability in N170 responses when viewing other-race faces. Responses to own-race faces were minimally influenced with only implicit racial bias predicting a significant amount of unique variability in N170 latency when viewing own-race faces. Face recognition, implicit racial bias, or their interaction did not predict P100 responses. The current findings suggest that face recognition abilities and its interaction with implicit racial bias modulate the early stages of other-race face processing.