An instance theory of associative learning

We present and test an instance model of associative learning. The model, Minerva-AL, treats associative learning as cued recall. Memory preserves the events of individual trials in separate traces. A probe presented to memory contacts all traces in parallel and retrieves a weighted sum of the traces, a structure called the echo. Learning of a cue–outcome relationship is measured by the cue’s ability to retrieve a target outcome. The theory predicts a number of associative learning phenomena, including acquisition, extinction, reacquisition, conditioned inhibition, external inhibition, latent inhibition, discrimination, generalization, blocking, overshadowing, overexpectation, superconditioning, recovery from blocking, recovery from overshadowing, recovery from overexpectation, backward blocking, backward conditioned inhibition, and second-order retrospective revaluation. We argue that associative learning is consistent with an instance-based approach to learning and memory.     

Poly-victimization: a neglected component in child victimization

OBJECTIVE: To assess the role of multiple victimization, or what is termed in this article "poly-victimization," in explaining trauma symptomatology. METHOD: In a nationally representative sample of 2,030 children ages 2-17, assessment was made of the past year's victimization experiences and recent trauma symptoms. RESULTS: Children experiencing four or more different kinds of victimization in a single year (poly-victims) comprised 22% of the sample. Poly-victimization was highly predictive of trauma symptoms, and when taken into account, greatly reduced or eliminated the association between individual victimizations (e.g., sexual abuse) and symptomatology. Poly-victims were also more symptomatic than children with only repeated episodes of the same kind of victimization. CONCLUSION: Researchers and practitioners need to assess for a broader range of victimizations, and avoid studies and assessments organized around a single form of victimization.