ABSTRACT
Sudden events and sharp discontinuities in the external world act as powerful attention attractors in adult humans. Does this reflex-like orienting towards targets deviating from their surround occur in early infancy? Here, we present evidence that, during the first months of life, infants orient preferentially towards repetitive visual patterns, rather than towards uniquely deviating targets. At 3-4 years of age, toddlers show an adult-like pattern of preferences. The transition from the infantile to the adult-like preferences occurs after the end of the first year of age. This development is parallelled by the emergence of novel neural and cognitive mechanisms. These maturational events might reflect the remodeling of the human brain during the transition from infancy to toddlerhood.
Subject(s)
Pattern Recognition, Visual/physiology , Aging/psychology , Attention/physiology , Child Development , Child, Preschool , Contrast Sensitivity/physiology , Field Dependence-Independence , Humans , Infant , Orientation , Photic Stimulation/methods , PsychophysicsABSTRACT
Inefficient visual search can become efficient with practice [Vision Research 35 (1995) 2037; 40 (2000) 2925]. In this study, we wondered whether this improvement depends on unique visual features associated with the target, on differences in item-specific brightness distribution between target and distractors, or only on a change in the allocation of attention and thus global search strategy. We found that both, unique visual features and differences in brightness distribution lead to parallelisation with practice of originally inefficient search. Prolonged practice of inefficient search tasks lacking both unique visual features and differences in brightness distribution (conjunctions) does not lead to improved performance, thus indicating that perceptual learning in visual search does not solely reflect an unspecific global improvement in search strategy. Changing the brightness polarity of the stimuli leads to instantaneous, complete transfer to the new task. There is no transfer but rather trade-off between the learning based on unique visual features or on differences in brightness distribution between target and distractors.
