Amygdala lesions eliminate viewing preferences for faces in rhesus monkeys

In free-viewing experiments, primates orient preferentially toward faces and face-like stimuli. To investigate the neural basis of this behavior, we measured the spontaneous viewing preferences of monkeys with selective bilateral amygdala lesions. The results revealed that when faces and nonface objects were presented simultaneously, monkeys with amygdala lesions had no viewing preference for either conspecific faces or illusory facial features in everyday objects. Instead of directing eye movements toward socially relevant features in natural images, we found that, after amygdala loss, monkeys are biased toward features with increased low-level salience. We conclude that the amygdala has a role in our earliest specialized response to faces, a behavior thought to be a precursor for efficient social communication and essential for the development of face-selective cortex.

Emergence of categorical face perception after extended early-onset blindness

It is unknown whether the ability to visually distinguish between faces and nonfaces is subject to a critical period during development. Would a congenitally blind child who gains sight several years after birth be able to acquire this skill? This question has remained unanswered because of the rarity of cases of late sight onset. We had the opportunity to work with five early-blind individuals who gained sight late in childhood after treatment for dense bilateral cataracts. We tested their ability to categorize patterns as faces, using natural images that spanned a spectrum of face semblance. The results show that newly sighted individuals are unable to distinguish between faces and nonfaces immediately after sight onset, but improve markedly in the following months. These results demonstrate preserved plasticity for acquiring face/nonface categorization ability even late in life, and set the stage for investigating the informational and neural basis of this skill acquisition.

The Influence of Averageness on Adults' Perceptions of Attractiveness: The Effect of Early Visual Deprivation

Adults who missed early visual input because of congenital cataracts later have deficits in many aspects of face processing. Here we investigated whether they make normal judgments of facial attractiveness. In particular, we studied whether their perceptions are affected normally by a face's proximity to the population mean, as is true of typically developing adults, who find average faces to be more attractive than most other faces. We compared the judgments of facial attractiveness of 12 cataract-reversal patients to norms established from 36 adults with normal vision. Participants viewed pairs of adult male and adult female faces that had been transformed 50% toward and 50% away from their respective group averages, and selected which face was more attractive. Averageness influenced patients' judgments of attractiveness, but to a lesser extent than controls. The results suggest that cataract-reversal patients are able to develop a system for representing faces with a privileged position for an average face, consistent with evidence from identity aftereffects. However, early visual experience is necessary to set up the neural architecture necessary for averageness to influence perceptions of attractiveness with its normal potency.

Too Much Television? Prospective Associations Between Early Childhood Televiewing and Later Self-reports of Victimization by Sixth Grade Classmates

BACKGROUND

Using a birth cohort, this study aimed to verify whether televiewing at 29 months, a common early childhood pastime, is prospectively associated with self-reported victimization at age 12.

METHODS

Participants are 991 girls and 1006 boys from the Quebec Longitudinal Study of Child Development. The main predictor comprised parent-reported daily televiewing by their children at 29 months. In the sixth grade, children reported how often they experienced victimization by classmates in the past year. The authors conducted multivariate linear regression, in which child self-reports of victimization were linearly regressed on early televiewing and potential confounders.

RESULTS

Every SD unit increase (0.88 hours) in daily televiewing at 29 months predicted an 11% SD unit increase in self-reported peer victimization by sixth grade classmates (unstandardized B = .031, p < .001, 95% confidence interval = 0.014-0.042). This relationship was adjusted for child characteristics (gender, preexisting externalizing behaviors, baseline cognitive abilities, and televiewing at age 12) and family characteristics (family configuration, income, and functioning, and maternal education).

CONCLUSIONS

Daily televiewing time at 29 months was associated with a subsequent increased risk of victimization by classmates at the end of sixth grade, a period which represents a critical developmental transition to middle school. Youth who experience peer victimization are at an increased risk of long-term mental health issues, such as depression, underachievement, and low self-esteem. This prospective association, across a 10-year period, suggests the need for better parental awareness, acknowledgement, and compliance with existing recommendations put forth by the American Academy of Pediatrics.