Perceptual Learning: 12‐Month‐Olds’ Discrimination of Monkey Faces

Abstract

Six-month-olds reliably discriminate different monkey and human faces whereas 9-month-olds only discriminate different human faces. It is often falsely assumed that perceptual narrowing reflects a permanent change in perceptual abilities. In 3 experiments, ninety-six 12-month-olds' discrimination of unfamiliar monkey faces was examined. Following 20 s of familiarization, and two 5-s visual-paired comparison test trials, 12-month-olds failed to show discrimination. However, following 40 s of familiarization and two 10-s test trials, 12-month-olds showed reliable discrimination of novel monkey faces. A final experiment was performed demonstrating 12-month-olds' discrimination of the monkey face was due to the increased familiarization rather than increased time of visual comparison. Results are discussed in the context of perceptual narrowing, in particular the flexible nature of perceptual narrowing.

Listening to the calls of the wild: The role of experience in linking language and cognition in young infants

“… 3 This duration is comparable to the exposure provided in other paradigms (e.g., Fair et al, 2012; Hannon & Trehub, 2005). …”

“…We focus specifically on the role of exposure. We know that exposure is instrumental as infants tune to the perceptual signals in their ambient environment (Doupe & Kuhl, 1999; Fair, Flom, Jones, & Martin, 2012; Friendly, Rendall, & Trainor, 2013; Kuhl et al, 1991; Werker & Tees, 1984). Might exposure also be a guiding force as infants tune the link between language and object categorization?…”

“…For example, providing 12-month-old infants with brief (less than one minute) exposure to monkey faces enabled them to reinstate their developmentally prior ability to discriminate among novel monkey faces, even months after their face perception had been tuned specifically to human (and no longer monkey) faces (Fair et al, 2012; for parallel work in music perception, see Hannon & Trehub, 2005; Trehub & Hannon, 2006). In addition, providing infants with persistent exposure—from 6 months (when infants still discriminate among monkey faces) until 9 months (when they would otherwise have tuned specifically to human faces)—enabled infants to maintain their perceptual discrimination of monkey faces (Pascalis et al, 2005; Scott & Monesson, 2009; for parallel work in other-race face perception, see Heron-Delaney, Wirth, & Pascalis, 2011).…”

Plasticity after perceptual narrowing for voice perception: reinstating the ability to discriminate monkeys by their voices at 12 months of age

“…Specifically, Fair et al (2012) demonstrated that 12-month-olds showed no evidence of discriminating unfamiliar monkey faces after 20 s of familiarization, but did discriminate them after 40 s of familiarization. This extended familiarization period could be considered a relatively brief form of training, but it is surprising that reinstatement could be achieved after such a brief training.…”

“…In interpreting the effects of different kinds of experience on reinstatement of abilities at 12 month of age, it is important to consider the results from a study by Fair et al (2012), in which sensitivity to distinctions in foreign-species (monkey) faces at 12 months was observed without a prescribed at-home training period, by simply by extending the length of the familiarization period at the time of testing. Specifically, Fair et al (2012) demonstrated that 12-month-olds showed no evidence of discriminating unfamiliar monkey faces after 20 s of familiarization, but did discriminate them after 40 s of familiarization.…”