Face Processing as a Brain Adaptation at Multiple Timescales

Correlations Between Psychological Status and Perception of Facial Expression

OBJECTIVE

Facial affect recognition is associated with neuropsychological status and psychiatric diseases. We hypothesized that facial affect recognition is associated with psychological status and perception of other affects.

METHODS

A total of 80 images depicting facial affect, including 20 Neutral, 20 Angry, 20 Fear, and 20 Sad, were screened for use in our research. A total of 100 healthy individuals were asked to rate these images using a 10-point Likert scale and complete psychological scales assessing the emotional statuses and cognitive functions.

RESULTS

The participants' emotional state of aggression, attention, and impulsivity may have been associated with their interpretation of the Angry facial expressions. The participants often rated the Angry facial expressions as Fear. The participants rated Fear images as Angry or Sad. In response to a Sad facial expression, the participants reported psychological statuses of attention and impulsivity which were associated with the facial expression rating. The participants rated the Sad expression as Angry or Fear.

CONCLUSION

The psychological statuses of the participants were significantly correlated with their interpretation of facial affects. In particular, a psychological state of attention was often correlated with incorrect affect ratings. Attention and impulsivity could affect the rating of the sad facial expressions.

The Detection of Face-like Stimuli at the Edge of the Infant Visual Field

Human infants are highly sensitive to social information in their visual world. In laboratory settings, researchers have mainly studied the development of social information processing using faces presented on standard computer displays, in paradigms exploring face-to-face, direct eye contact social interactions. This is a simplification of a richer visual environment in which social information derives from the wider visual field and detection involves navigating the world with eyes, head and body movements. The present study measured 9-month-old infants’ sensitivities to face-like configurations across mid-peripheral visual areas using a detection task. Upright and inverted face-like stimuli appeared at one of three eccentricities (50°, 55° or 60°) in the left and right hemifields. Detection rates at different eccentricities were measured from video recordings. Results indicated that infant performance was heterogeneous and dropped beyond 55°, with a marginal advantage for targets appearing in the left hemifield. Infants’ orienting behaviour was not influenced by the orientation of the target stimulus. These findings are key to understanding how face stimuli are perceived outside foveal regions and are informative for the design of infant paradigms involving stimulus presentation across a wider field of view, in more naturalistic visual environments.

Age norms for grating acuity and contrast sensitivity measured by Lea tests in the first three years of life

AIM

To determine age norms in the first three years of life for grating visual acuity and contrast sensitivity obtained with Lea grating test and Hiding Heidi low contrast face test.

METHODS

Lea grating test was used to estimate binocular grating acuity and Hiding Heidi low contrast face test was used to estimate contrast sensitivity in 600 healthy infants and children. Age ranged from 3 to 36mo subdivided into 12 groups subjected for full ophthalmologic and pediatric examinations.

RESULTS

The grating acuity developed along the first three years of life. It ranged from 1.88±0.32 c/d at 3mo to 30.95±0.77 c/d at 36mo. The most rapid development was during the first 12mo and the slowest development was from 30 to 36mo. The contrast sensitivity showed rapid development in the first two years of life. Its mean value ranged from 4.23±1.17 at 3mo to 78.26±8.21 at 24mo. It was constant at the highest score (80) thereafter.

CONCLUSION

Age norms for grating acuity along with contrast sensitivity offer a more comprehensive measure of spatial vision and should be incorporated in clinical practice for better visual assessment in preverbal and nonverbal children.

Fast Detector/First Responder: Interactions between the Superior Colliculus-Pulvinar Pathway and Stimuli Relevant to Primates

Primates are distinguished from other mammals by their heavy reliance on the visual sense, which occurred as a result of natural selection continually favoring those individuals whose visual systems were more responsive to challenges in the natural world. Here we describe two independent but also interrelated visual systems, one cortical and the other subcortical, both of which have been modified and expanded in primates for different functions. Available evidence suggests that while the cortical visual system mainly functions to give primates the ability to assess and adjust to fluid social and ecological environments, the subcortical visual system appears to function as a rapid detector and first responder when time is of the essence, i.e., when survival requires very quick action. We focus here on the subcortical visual system with a review of behavioral and neurophysiological evidence that demonstrates its sensitivity to particular, often emotionally charged, ecological and social stimuli, i.e., snakes and fearful and aggressive facial expressions in conspecifics. We also review the literature on subcortical involvement during another, less emotional, situation that requires rapid detection and response-visually guided reaching and grasping during locomotion-to further emphasize our argument that the subcortical visual system evolved as a rapid detector/first responder, a function that remains in place today. Finally, we argue that investigating deficits in this subcortical system may provide greater understanding of Parkinson's disease and Autism Spectrum disorders (ASD).

Probing Intrinsic Resting-State Networks in the Infant Rat Brain

Resting-state functional magnetic resonance imaging (rs-fMRI) measures spontaneous fluctuations in blood oxygenation level-dependent (BOLD) signal in the absence of external stimuli. It has become a powerful tool for mapping large-scale brain networks in humans and animal models. Several rs-fMRI studies have been conducted in anesthetized and awake adult rats, reporting consistent patterns of brain activity at the systems level. However, the evolution to adult patterns of resting-state activity has not yet been evaluated and quantified in the developing rat brain. In this study, we hypothesized that large-scale intrinsic networks would be easily detectable but not fully established as specific patterns of activity in lightly anesthetized 2-week-old rats (N = 11). Independent component analysis (ICA) identified 8 networks in 2-week-old-rats. These included Default mode, Sensory (Exteroceptive), Salience (Interoceptive), Basal Ganglia-Thalamic-Hippocampal, Basal Ganglia, Autonomic, Cerebellar, as well as Thalamic-Brainstem networks. Many of these networks consisted of more than one component, possibly indicative of immature, underdeveloped networks at this early time point. Except for the Autonomic network, infant rat networks showed reduced connectivity with subcortical structures in comparison to previously published adult networks. Reported slow fluctuations in the BOLD signal that correspond to functionally relevant resting-state networks in 2-week-old rats can serve as an important tool for future studies of brain development in the settings of different pharmacological applications or disease.

Brain adaptation and alternative developmental trajectories

Resilience and adaptation in the face of early genetic or environmental risk has become a major interest in child psychiatry over recent years. However, we still remain far from an understanding of how developing human brains as a whole adapt to the diffuse and widespread atypical synaptic function that may be characteristic of some common developmental disorders. The first part of this paper discusses four types of whole-brain adaptation in the face of early risk: redundancy, reorganization, niche construction, and adjustment of developmental rate. The second part of the paper applies these adaptation processes specifically to autism. We speculate that key features of autism may be the end result of processes of early brain adaptation, rather than the direct consequences of ongoing neural pathology.

Developmental origins of the face inversion effect

A hallmark of adults' expertise for faces is that they are better at recognizing, discriminating, and processing upright faces compared to inverted faces. We investigate the developmental origins of "the face inversion effect" by reviewing research on infants' perception of upright and inverted faces during the first year of life. We review the effects of inversion on infants' face preference, recognition, processing (holistic and second-order configural), and scanning as well as face-related neural responses. Particular attention is paid to the developmental patterns that emerge within and across these areas of face perception. We conclude that the developmental origins of the inversion effect begin in the first few months of life and grow stronger over the first year, culminating in effects that are commonly thought to indicate adult-like expertise. We posit that by the end of the first year, infants' face-processing system has become specialized to upright faces and a foundation for adults' upright-face expertise has been established. Developmental mechanisms that may facilitate the emergence of this upright-face specialization are discussed, including the roles that physical and social development may play in upright faces' becoming more meaningful to infants during the first year.

The two-process theory of face processing: modifications based on two decades of data from infants and adults

Johnson and Morton (1991. Biology and Cognitive Development: The Case of Face Recognition. Blackwell, Oxford) used Gabriel Horn's work on the filial imprinting model to inspire a two-process theory of the development of face processing in humans. In this paper we review evidence accrued over the past two decades from infants and adults, and from other primates, that informs this two-process model. While work with newborns and infants has been broadly consistent with predictions from the model, further refinements and questions have been raised. With regard to adults, we discuss more recent evidence on the extension of the model to eye contact detection, and to subcortical face processing, reviewing functional imaging and patient studies. We conclude with discussion of outstanding caveats and future directions of research in this field.

Annual research review: Towards a developmental neuroscience of atypical social cognition

As a starting point for our review we use a developmental timeline, starting from birth and divided into major developmental epochs defined by key milestones of social cognition in typical development. For each epoch, we highlight those developmental disorders that diverge from the normal developmental pattern, what is known about these key milestones in the major disorders affecting social cognition, and any available research on the neural basis of these differences. We relate behavioural observations to four major networks of the social brain, that is, Amygdala, Mentalizing, Emotion and Mirror networks. We focus on those developmental disorders that are characterized primarily by social atypicality, such as autism spectrum disorder, social anxiety and a variety of genetically defined syndromes. The processes and aspects of social cognition we highlight are sketched in a putative network diagram, and include: agent identification, emotion processing and empathy, mental state attribution, self-processing and social hierarchy mapping involving social ‘policing’ and in-group/out-group categorization. Developmental disorders reveal some dissociable deficits in different components of this map of social cognition. This broad review across disorders, ages and aspects of social cognition leads us to some key questions: How can we best distinguish primary from secondary social disorders? Is social cognition especially vulnerable to developmental disorder, or surprisingly robust? Are cascading notions of social development, in which early functions are essential stepping stones or building bricks for later abilities, necessarily correct?

The face inversion effect in infants is driven by high, and not low, spatial frequencies

To investigate the mechanisms underlying development of upright face preferences in infants, the current study measured inversion effects for faces that were spatial frequency (SF) filtered, into low SF and high SF, with the notion that different SFs are analyzed by different visual mechanisms. For comparison to faces, we used object stimuli that consisted of pictures of strollers. In 4 month olds, 8 month olds, and adults, we measured the strength of the selective face inversion effect (sFIE), operationally defined as an upright over inverted looking preference that is greater for faces than objects. In Study 1, we employed unfiltered stimuli, and found a clear sFIE in both infants and adults. To determine what drove this sFIE, in Study 2, the sFIE was measured for low-SF and high-SF stimuli, with all stimuli being equated for visibility. For adults, the sFIE was equally strong for low-SF and high-SF stimuli. A different pattern was seen for infants. Infants exhibited a significantly greater sFIE for high-SF, than for low-SF, stimuli (and only for high SF was the sFIE significant). In fact, the strength of infants' upright face preference for high-SF stimuli was indistinguishable from that observed for unfiltered faces, indicating that in natural (unfiltered) stimuli, high SFs are sufficient to account for infants' upright face preferences.

Development of face discrimination abilities, and relationship to magnocellular pathway development, between childhood and adulthood

The current study tested the development of face and object processing in young children (mean age = 5.24 years), adolescents (mean age = 15.8 years), and adults (mean age = 21.1 years) using stimuli that were equated for low-level visual characteristics (luminance, contrast, and spatial frequency make-up) and methods that equate for difficulty across ages. We also tested sensitivity to luminance and chromatic contrast (i.e., thought to be mediated primarily by the subcortical Magnocellular (M) and Parvocellular (P) pathways, respectively) to determine whether age-related improvements in face or object discrimination were driven by age-related changes in the M and/or P pathways. Results showed a selective age-related improvement in face sensitivity and a relationship between age-related increases in face sensitivity and luminance contrast sensitivity. These results add to the mounting evidence that the M pathway may influence face processing.