Proactive and Retroactive Interference Effects in Development.

Proactive and Retroactive Interference Effects in Development Kevin Darby (darby.60@osu.edu) Department of Psychology, 1835 Neil Ave. Columbus, OH 43210 USA Vladimir M. Sloutsky (sloutsky.1@osu.edu) Department of Psychology, 1835 Neil Ave. Columbus, OH 43210 USA Abstract Infants and children are avid learners. This constant aggregation of new knowledge, however, can interfere with past and future learning. Proactive interference (PI) occurs when past learning interferes with new learning, while retroactive interference (RI) is the attenuation of memory for previous learning as a result of new knowledge. Previous work has demonstrated that adults and children display PI and RI effects, but the developmental trajectories of these effects are less clear. The current study developed a new associative learning paradigm to concurrently test PI and RI in preschoolers and adults. Results demonstrated the presence of RI, and these effects were stable across age groups, suggesting that the mechanisms that modulate RI effects may already be mature in these age groups. No PI effects were found in either group, however. This surprising result suggests the role of associative complexity as a possible modulator of PI in these age groups. Keywords: Learning; memory development; proactive interference; retroactive interference. Interference effects have been the focus of a great deal of research. It is clear, for example, that interference occurs in many different learning systems, including connectionist networks (French, 1999; Ratcliff, 1990) and human adults (Bower, Thompson-Schill, & Tulving, 1994; Wixted, 2004). In adults, RI effects may be modulated by similarity between learning sets as well as mental effort, such that more interference is demonstrated with greater similarity and increased cognitive load (Dewar, Cowan, & Della Sala, 2007; French, 1999; Wixted, 2004). Additionally, RI seems to be modulated by the engagement of networks in the hippocampal region and surrounding cortices (McClelland, McNaughton, & O’Reilly, 1995; Wiskott, Rasch, & Kempermann, 2006). Conversely, PI effects seem to be modulated by executive functions such as attentional control and inhibition of prepotent responses (Baker, Friedman, & Leslie, 2010; Dick, 2012; Kiesel et al., 2010), and appear to be attenuated by activity in prefrontal regions of the cortex (Badre & Wagner, 2005). Interference effects Interference in development Infants and children are avid learners: they constantly acquire new knowledge. This new knowledge not only expands their sense of the world, but also affects what they already know and what they will learn in the future (Wixted, 2004). Some of these effects are counterintuitive: (1) acquired knowledge may interfere with future learning, the process known as proactive interference (PI), and (2) acquired knowledge may attenuate memory for previously learned information, the process known as retroactive interference (RI). PI and RI effects are particularly important to study in early development because doing so will help determine what factors benefit or detract from the aggregation of early knowledge. These sources of forgetting may play a role in many early cognitive domains, such as categorization (Mareschal, Quinn, & French, 2002) and word learning (Levy-Gigi & Vakil, 2010). Imagine, for example, that a child with bilingual parents learns the word “cat,” but is later introduced to the word “gato.” Mapping “gato” onto the child’s category of cats may be more difficult than learning an entirely new concept in Spanish since the category is already associated with “cat” (PI). Additionally, the mapping between the word “cat” and the category of cats will likely be weakened as a result of learning to associate the category with a second word (RI). Although the majority of research concerning PI and RI has focused on adults, some evidence suggests that interference effects may also be present early in human development. For example, infants demonstrate RI in a visual recognition task (Turati, 2008) as well as a mobile reinforcement paradigm (Rossi-George & Rovee-Collier, 1999), and demonstrate PI in visual facial recognition (Tyrrell, Snowman, Beier, & Blanck, 1990). Despite the fact that interference occurs across development, the development of the ability to resist each kind of interference is less clear. There is some evidence that RI effects are relatively stable between preschool and school years. Howe (1995) demonstrated that RI effects were similar in preschoolers (approximately 4.5 years) and kindergarteners (approximately 6 years old) in a paired- associate recall task. Similar findings were reported in 4- and 7-year-olds, using a game-based paradigm (Lee & Bussey, 2001). It is unclear, however, whether there are developmental differences in RI if a wider age range is considered. In contrast, developmental differences in PI have been reported. Kail (2002) performed a meta-analysis on PI effects in children ages 4-13 years old, as well as an experiment with children in grades 3-6 and undergraduate adults. Both the meta-analysis and experimental results