Edited by: Snehlata Jaswal, Indian Institute of Technology, Jodhpur, India
Reviewed by: Tandra Ghose, Technical University of Kaiserslautern, Germany; Stefano Federici, University of Perugia, Italy
*Correspondence: Flávia de Lima Osório, Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto – USP, Avenida dos Bandeirantes 3900, CEP 14048-900, Ribeirão Preto, São Paulo, Brazil e-mail:
This article was submitted to Cognitive Science, a section of the journal Frontiers in Psychology.
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Exposure to maltreatment is associated with biological, psychological, and social development impairments in children. This systematic literature review sought to determine whether an association exists between child maltreatment and facial emotion processing and recognition. The search was conducted using the databases PubMed, PsycINFO, and SciELO using the following keywords: “maltreatment,” “adversity,” “neglect,” “sexual abuse,” “emotional abuse,” “physical abuse,” “child*,” “early,” “infant,” “face,” “facial,” “recognition,” “expression,” “emotion*,” and “impairment.” Seventeen articles were selected and analyzed. Maltreated children tended to exhibit less accuracy in global facial tasks and showed greater reactivity, response bias, and electrophysiological activation of specific brain areas in response to faces expressing negative emotions, especially anger. We concluded that the results of this review are exploratory and non-conclusive due to the small number of studies published and the wide variety of aims and procedures. Those shortcomings notwithstanding, the results indicate definite tendencies and gaps that should be more thoroughly explored in future studies.
Child maltreatment encompasses any act of omission or commission by a parent or caregiver that results in harm or the potential for harm, regardless of intent (Gilbert et al.,
Maltreatment during childhood is associated with several consequences that impair the biological, psychological, and social domains of human development (Kaufman et al.,
Child maltreatment is also associated with deficiencies in social cognition, including the processing and recognition of facial emotion expressions (Cicchetti and Carlson,
Psychobiological processes, which are modulated by different cerebral regions and neurocognitive systems, are understood as facial emotion processing when perceiving and assessing emotions. The processing of emotions, especially “basic” emotions (i.e., happiness, sadness, anger, fear, disgust, and surprise), involves several nervous system structures, especially the amygdala and prefrontal cortex. These neural substrates mature in parallel with development, yielding a greater refinement of emotional processing (Herba et al.,
Based on the assumption that children adjust their perceptual mechanisms to process the features that are most outstanding and familiar in their environments through the learning of social experiences, child maltreatment has been suggested to change sensory thresholds, causing less effective regulation, processing, and recognition of emotions (Pollak,
Because no thorough literature review has yet presented general conclusions on this subject and because the systematization of data in the literature is highly relevant, the present study provides a systematic literature review to establish the relationship between child maltreatment and the processing and recognition of facial expressions of emotion.
A systematic review of the literature was conducted according to the Cochrane protocol, without time limits, using the databases PubMed, PsycINFO, and SciELO with the following keywords: “maltreatment or adversity or neglect or sexual abuse or emotional abuse or physical abuse,” “child* or early or infant,” “face or facial,” and “recognition or expression or emotion* or impairment.” In addition, the references quoted by the selected articles were manually surveyed to broaden the scope of the review.
The process and criteria for article inclusion and exclusion are depicted in Figure
Seventeen articles were included in the present review. Two psychologists with significant experience in this field assessed these articles for pertinence and compliance with the inclusion and exclusion criteria.
The search revealed that interest in the investigated topic began in the 1980s (
All studies exhibited the same methodological designs (i.e., case-control studies). The investigations could be classified in two groups based on their aims: the first group's primary aim was to assess the recognition of facial emotion, whereas the second group focused on facial emotion processing. Nine studies employed facial expression recognition tasks (Camras et al.,
The major sociodemographics analyzed are listed in Table
1 |
Camras et al., |
US | 17 (♂ = 11/♀ = 6) | 5 | NEG, UA | PPTPCA | 17 (♂ = 11/♀ = 6) | 5 | School |
2 |
Camras et al., |
US | 20 (♂ = 10/♀ = 10) | 4.9 | NEG, UA | PPTPCA | 20 (♂ = 10/♀ = 10) | 4.9 | School |
3 |
Camras et al., |
US | 20 (♂ = 10/♀ = 10) | 4.9 | NEG, PA | PPTPCA | 20 (♂ = 10/♀ = 10) | 4.9 | School |
4 |
During and McMahon, |
US | 23 (♂ = 15/♀ = 8) | 4.9 (1.8) | NEG, PA | PPTPCA | 23 (♂ = 13/♀ = 10) | 5.2 (2.5) | Ad |
5 |
Pollak et al., |
US | 23 (♂ = 18/♀ = 5) | 9.2 (1.6) | NEG, PA | PPTPCA | 21 (♂ = 17/♀ = 4) | 9.2 (1.1) | GP |
6 |
Pollak et al., |
US | 33 (♂ = 21/♀ = 12) | 4.4 | NEG, PA | PPTPCA | 15 (♂ = 8/♀ = 7) | 4.3 (0.5) | UPC |
7 |
Pollak et al., |
US | 28 (♂ = 18/♀ = 10) | 9.1 (1.7) | NEG, PA | PPTPCA | 14 (♂ = 10/♀ = 4) | 8.5 (1.6) | GP |
8 |
Pollak and Sinha, |
US | 24 (♂ = 17/♀ = 7) | 9.3 (1.6) | PA | PPTPCA | 23 (♂ = 16/♀ = 7) | 9.4 (1.5) | PPTPCA |
9 |
Pollak and Kistler, |
US | 23 (♂ = ?/♀ = ?) | 9.25 | PA | PF/SWA | 17 (♂ = ?/♀ = ?) | 9.25 | PPTPCA |
10 |
Pollak and Tolley-Schell, |
US | 14 (♂ = 8/♀ = 6) | 10.1 (1.2) | PA | DHS | 14 (♂ = 9/♀ = 5) | 10 (1.1) | Ad |
11 |
Cicchetti and Curtis, |
US | 35 (♂ = 16/♀ = 19) | 2.6 (0.15) | NEG, PA, SA | DHS | 24 (♂ = 15/♀ = 9) | 2.5 (0.1) | CSS |
12 |
Pine et al., |
US | 34 (♂ = 15/♀ = 19) | 10.3 (1.8) | DV | DCFS | 21 (♂ = 7/♀ = 14) | 9.9 (1.8) | DCFS |
13 |
Masten et al., |
US | 29 (♂ = 14/♀ = 15) | 11.3 (1.4) | NEG, PA, SA | PPTPCA | 17 (♂ = 7/♀ = 10) | 12 (2.0) | GP |
14 |
Pollak et al., |
US | 49 (♂ = 25/♀ = 24) | 9.5 (0.1) | PA | PPTPCA | 46 (♂ = 23/♀ = 23) | 9.5 (0.1) | GP |
15 |
McCrory et al., |
UK | 20 (♂ = 14/♀ = 6) | 9.5 (1.4) | NEG, PA, SA, EA | CSS | 23 (♂ = 11/♀ = 12) | 12.5 (1.17) | School/Ad |
16 |
McCrory et al., |
UK | 18 (♂ = 12/♀ = 6) | 12.1 (1.4) | PA, DV | CSS | 23 (♂ = 11/♀ = 12) | 12.5 (1.2) | School/Ad |
17 |
Curtis and Cicchetti, |
US | 25 (♂ = 12/♀ = 13) | 1.3 (0.05) | NEG, PA, EA | DHS | 20 (♂ = 8/♀ = 12) | 1.3 (0.1) | CSS |
The clinical and control groups were homogeneous with regard to gender, age, and social condition across all studies. On average, 25.5 children (median = 23) participated in the clinical samples, and 21 children (median = 20) participated in the controls. All studies included males and females. The average ages of the clinical groups and controls were 7.3 and 7.6 years, respectively.
Most clinical group volunteers were recruited from prevention, treatment, or protection against child maltreatment programs, departments of human services, or community-based social services. The control group volunteers were recruited from the general population from schools, via advertising in newspapers, Internet resources, and community-based services, among others.
The major inclusion criterion in all of the studies was the presence or absence of global or specific child maltreatment. The assessment and confirmation of child maltreatment were based on an analysis of clinical and legal reports at institutions or services specializing in maltreatment by professionals, investigators, or specialists. In the analysis, or to complement the available data, the authors used several instruments including guidelines and scales (see Table
Source/complementary instruments ( |
The Guidelines of Manly, Cicchetti and Barnett, |
Parent–Child Conflict Tactics Scale ( |
|
Dunedin Abuse Scales ( |
|
Child Bad Experience Quesntionnaire ( |
|
The Guidelines of Kaufman et al., |
|
The Guidelines of Guyer et al., |
|
Child Abuse Potential Inventory ( |
|
Child Trauma Questionnaire in an adolescente psychiatric population ( |
|
Standardized Questionnaire Assessing Level of Domestic Violence ( |
|
State-Trait Anger Expression Inventory ( |
|
Self-report of children ( |
|
Interviews with parents ( |
|
Maternal Maltreatment Interview ( |
Approximately 47% of the studies (
As mentioned above, the studies included in the present review pursued two separate aims and therefore used different techniques. Thus, the procedures described in the present review take this division into consideration.
The major features of the various procedures are described in Table
Task | Identify emotion ( |
Identify target ( |
View faces ( |
||
Identify gender ( |
||
Type of stimuli | Verbal history+facial photographs ( |
Paired images of emotions+target ( |
Dynamic facial images on screen ( |
Pictures of facial emotions ( |
|
Name of emotion+facial photographs ( |
||
Set of images/stimuli | Standardized: yes ( |
Standardized: yes ( |
N° of stimuli: mean = 77.25 | N° of stimuli: mean = 304.3 | |
median = 31 | median = 160 | |
Color: black/white ( |
Color: black/white ( |
|
color ( |
||
N° of participants: mean = 8.25 | N° of participants: mean = 25.5 | |
median = 8 | median = 3 | |
Participant age: child ( |
Participant age: adult ( |
|
adult ( |
||
not specified ( |
||
Participant gender: female ( |
Participant gender: female ( |
|
female/ male ( |
female/male ( |
|
not specified ( |
||
Evaluated emotions( |
Evaluated emotions( |
|
fear ( |
happiness ( |
|
sadness ( |
neutral ( |
|
anger ( |
fear ( |
|
disgust ( |
||
surprised ( |
||
neutral ( |
||
Outcomes( |
Accuracy ( |
Latency time of target/gender ( |
Intensity/ distinctness ( |
EEG: amplitude and/or latency ( |
|
Response bias ( |
Accuracy of target/gender ( |
|
fMRI: amygdala and anterior insula activation ( |
||
Attention bias ( |
As Table
Although the tasks in all nine studies investigating facial emotion recognition consisted of identifying emotions from pictures, they used different photographs or dynamic images; others presented verbal stories or emotion-evoking words. The eight studies that investigated facial emotion processing sought to focus the volunteers' attentions on faces, which were most often displayed quickly and in pairs. For this purpose, most studies (Pollak et al.,
The stimuli used in all studies were standardized (Ekman and Friesen,
Wide variety was also found with regard to the assessed emotions; happiness and anger were most frequently investigated in both types of studies.
The major results of the studies are described in Table
Recognition Task | MT = C | Anger | |||||
( |
( |
MT = C | MT < C | Anger | Anger | ||
MT < C | ( |
( |
MT < C ( |
MT = C ( |
|||
( |
MT < C ( |
Fear | MT > C ( |
||||
Disgust | MT = C ( |
Sadness | |||||
MT = C ( |
MT < C ( |
MT = C ( |
|||||
MT < C ( |
Sadness | MT > C ( |
|||||
Sadness | MT = C ( |
||||||
MT = C | MT > C ( |
||||||
( |
|||||||
MT < C ( |
|||||||
Processing Task | MT = C | Anger | |||||
( |
( |
MT < C | MT = C | Anger: | Anger | MT = C( |
Anger Neutral: MT > C |
MT < C | ( |
( |
MT = C | MT = C ( |
( |
||
( |
Fear: | MT > C ( |
( |
MT (physical): ↑MT severity | Anger | Happiness/Neutral: MT > | |
MT = C | Fear | severity↑stimulus | MT = C ( |
MT = C ( |
|||
( |
MT = C ( |
avoidance ( |
MT > C ( |
||||
Happiness | Happiness | MT (neglect): no | MT < C ( |
Anger /Sadness: MT > C | |||
MT = C ( |
MT = C ( |
correlation ( |
Happiness | MT = C ( |
|||
Neutral | Neutral | Happiness | MT < C ( |
||||
MT = C ( |
MT = C | MT = C ( |
MT > C ( |
Anger: ↑activation ↑MT | |||
( |
MT (physical, | MT < C ( |
precocity ( |
||||
neglect): | |||||||
no correlation | Anger/Sadness: MT > C | ||||||
( |
( |
||||||
Neutral | Anger: ↑activation ↑MT | ||||||
MT = C ( |
severity ( |
||||||
Anger /Neutral: MT > C | |||||||
( |
With regard to accuracy in the recognition task, 71% of the studies (Camras et al.,
With regard to the assessment of global facial expression processing, 60% of studies did not find evidence of impairment (Pollak et al.,
A second set of outcomes included the intensity or sharpness of faces in the recognition task and the latency times of the processing task. The intensity necessary for the global identification of emotions, evaluated by the morphing techniques, was not significantly different between groups. However, three out of the four studies (Pollak and Kistler,
No study found differences in response latency or target identification between maltreated children and controls with regard to the processing of either global or specific tasks.
Three out of the five studies (Pollak and Sinha,
Five facial expression-processing studies used electroencephalography (EEG) to assess event-related potentials (ERPs): electrical potentials in the brain directly related to the presentation of a stimulus. In particular, 60% of those studies (Pollak et al.,
Two studies (McCrory et al.,
The results revealed that few studies have been conducted thus far in this specific field, and the number of consistent findings in the present review is relatively small. In addition, most such studies have been conducted in developed countries with better psychosocial and economic conditions compared with the rest of the world, which might have influenced the occurrence and experience of abuse. Therefore, because the findings of the present review apply to specific social conditions, they cannot be generalized to developing countries. Thus, studies with children from different countries and subjected to different social conditions are necessary.
In this regard, Garbarino and Kostelny (
The samples in the current review were relatively small, and the specificity of the various types of child maltreatment was given little attention: 41.2% of the studies (Camras et al.,
The results revealed that previous studies have employed a wide variety of procedures; a single methodological standard to investigate the recognition and processing of facial expressions is not yet available. Thus, the large diversity of adopted procedures hampers more precise comparisons and conclusive results, such as is the case of those from meta-analytical studies. Although qualitative data analysis does not point toward a bias of results as a function of the used procedures, the different methodological variables are known to influence this process.
Specifically, the literature indicates that task performance is often influenced by variables related to the respondents and the procedures applied. Among these influential factors, the following stand out: (a) type of task; (b) task demand level; and (c) respondent age and gender (Durand et al.,
The study conducted by Bruce et al. (
With regard to respondent characteristics, the literature review conducted by McClure (
Regarding the influence of those variables on the results of the present review, approximately half of the studies (Camras et al.,
One of the major findings of this review was regarding the accuracy rate, where most of the studies (
With regard to neurobiological factors, the literature indicates that major stressors during child development can harm cognitive functions and the development of significant brain areas (Teicher,
From the environmental and learning point of view, it is hypothesized that different family environments experienced by abused children may influence the ease of recognition of specific emotions. Depending on the family environment, some types of emotions would be more experienced and expressed and, hence, more easily recognized, while other types of emotions (less familiar) would have their recognition hampered. This hypothesis supports the results from the study by Pollak et al. (
Notably, this was the only study to show that abused children present more errors while recognizing faces with negative emotions and the only to evidence specificities on the answers as a function of the type of trauma experienced by the children. Children who are victims of negligence present more difficulties in detecting negative emotions, such as anger, compared with the control group, whereas children who are victims of physical abuse present more difficulties detecting negative emotions, such as sadness and disgust. These results have not been presented by studies other than the present review, and they indicate the following relevant aspect: different types of traumas may be associated in a specific manner to different impairments in recognizing facial emotions. Thus, it is important that researchers consider the impact of each variable alone.
With regard to the relevance of the environment, MacMillan et al. (
The present review also found differences between maltreated children and controls regarding the intensity of emotion necessary for anger recognition. These results corroborate those of Pollak (
In the present review, an assessment of the intensity required to recognize facial emotions in dynamic tasks showed that children (abused) best recognize faces expressing anger with the lowest level of available information, compared with the control group. These results suggest that children subjected to maltreatment might be hypervigilant and more reactive to signs of anger. In turn, this might affect their development by increasing their level of anxiety and their predisposition to aggressive reactions (Shackman et al.,
Nevertheless, the emotion of anger was not systematically accurate. One of the studies that assessed response and attention bias found that the maltreated group exhibited a greater tendency to attribute anger and sadness to faces with other basic emotions, and another study reported that higher levels of abuse predicted the tendency to avoid anger stimuli during the task. Similarly, one study conducted on a sample of adolescents found that exposure to severe abuse was associated with the better detection of and greater response bias regarding anger (Gibb et al.,
Previous authors have speculated that response biases might be caused by learning and the emotional experiences to which children are exposed in the family environment. This effect might occur when the parents' or family's ability to express emotions is limited or highly aggressive, thereby impairing the interpretation of emotions in general (Dunn et al.,
According to the literature, the neurological processing of anger and fear is closely related to a system that involves the amygdala and related areas such as the thalamus, insula, rostral anterior cingulate, and prefrontal cortex (Keightley et al.,
The neurophysiological data reported by the studies included in the present review indicate that the perception of angry faces is associated with increased EEG wave amplitude and greater fMRI activation of brain areas such as the right and left amygdala and the bilateral and left anterior insula.
The amygdala likely plays relevant roles in fear conditioning, aggression control, emotional memory, and the fight-or-flight response, whereas excessive activation in response to negative stimuli is associated with anxious traits, post-traumatic stress disorder, major depression, and cognitive bias (Edwards et al.,
One of the studies (McCrory et al.,
The fMRI studies also found that the activation of the amygdala and anterior insula in response to angry faces was correlated with earlier onset and greater severity of maltreatment. In addition, other studies found that onset age and maltreatment length might increase developmental impairments (Lee and Hoaken,
This first systematic literature review on the current subject was exploratory and inconclusive due to the aforementioned limitations, the methodological diversity among studies, and sample restrictions in particular. These limitations notwithstanding, the studies showed that maltreated children are less accurate than controls with regard to global facial recognition and processing tasks. In addition, these children exhibited greater reactivity, response biases, and electrophysiological activation of the amygdala and anterior insula to faces expressing negative emotions, especially anger.
Additional studies are needed that (a) apply standard procedures to control the variables that influence facial expression recognition and processing; (b) include large samples that represent different social contexts; (c) analyze the effect of the specific types of maltreatment; (d) measure and control relevant variables such as onset age and maltreatment length; and (e) map the effect of protective factors such as participation in preventive and therapeutic programs.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Research funding was provided by FAPESP - Fundação de Amparo à Pesquisa do Estado de São Paulo (Process No. 2012/02260-7).