Clay Mash

Discrimination of facial expression by 5-month-old infants of nondepressed and clinically depressed mothers.

Five-month-old infants of nondepressed and clinically depressed mothers were habituated to either a face with a neutral expression or the same face with a smile. Infants of nondepressed mothers subsequently discriminated between neutral and smiling facial expressions, whereas infants of clinically depressed mothers failed to make the same discrimination.

Experience‐Based and On‐Line Categorization of Objects in Early Infancy

What processes do infants employ in categorizing? Infants might categorize on line as they encounter category-related entities; alternatively, infants might depend on prior experience with entities in formulating categories. These alternatives were tested in forty-four 5-month-olds. Infants who were familiarized in the laboratory with a category of never-before-seen objects subsequently treated novel objects of the same category as familiar-they categorized on line-just as did infants who were exposed to objects from the same category at home for 2 months leading to their laboratory assessment of object categorization. Infants with home experience also recognized novel category objects as familiar from the outset-that is, prior experience with category exemplars was brought to bear in laboratory tasks.

Brain dynamics in young infants' recognition of faces: EEG oscillatory activity in response to mother and stranger.

The brain electrical responses of 3-month-old infants were compared between images of familiar and unfamiliar faces. Infants were shown images of their mothers and of appearance-matched female strangers for 500 ms per trial while their electroencephalography was recorded. Electroencephalographic signals were segmented from stimulus onset through 1200 ms, and segments were analyzed in the time–frequency domain with a continuous wavelet transform. Differentiated responses were apparent in three time windows: 370–480, 610–690, and 830–960 ms. Across response windows, event-related synchronization or desynchronization was observed in beta or gamma frequency bands at the left frontal, midline central, bilateral temporal, and right parietal sites. In conclusion, these findings provide the first evidence of organized brain activity underlying familiar face recognition in very young infants and are discussed in relation to comparable patterns that have been observed in adults.