April CNS Meeting
In April, Profs Michael Ramscar and Sam McClure will be presenting at the 18th Annual Cognitive Neuroscience meeting in San Francisco. They will report the first neurobiological evidence for Feature-Label-Order Effects in learning.
Manipulating information structure as a method of localizing information processing in the brain
When formalized in terms of prediction and cue competition, symbolic learning takes two forms: learning to predict labels from the features of objects and events (Feature-to-Label learning), or learning to predict features from labels (Label-to-Feature learning). When the information available in training is structured in one or another of these formats, qualitative differences in symbolic learning occur. Discrimination learning is facilitated when objects precede labels (FL), because the structure of information promotes cue competition between individual features. However, this competition is inhibited when labels predict objects (LF; Ramscar et al, 2010). We report an fMRI investigation of these Feature-Label-Ordering effects in learning. Participants were trained and tested on a category-learning task while the frequency of confusable categories was manipulated so that successful discrimination was essential to successful categorization. Participants trained to predict labels from features (FL) showed higher levels of dorsal striatal activity (caudate and putamen), which correlated with overall performance at test. The opposite pattern was observed with ventrolateral prefrontal cortex (VLPFC) activation, which was greater in participants trained to predict features from labels (LF), and which correlated negatively with performance on the difficult to discriminate low frequency items. The increased striatal activity we observed in the FL-trained participants is consistent with evidence linking this area to discrimination learning, while the correlation between VLPFC activity and poorer discrimination in the LF-trained participants supports the idea that the structure of information in training forced participants to rely on working memory, fixating on cues that were frequent, salient, and yet ultimately uninformative.