HAL-based evolutionary inference for pattern induction from psychiatry web resources

Negative and stressful life events play a significant role in triggering depressive episodes. Psychiatric services that can identify such events efficiently are vital for mental health care and prevention. Meaningful patterns, e.g., <lost, parents>, must be extracted from psychiatric texts before these services can be provided. This study presents an evolutionary text-mining framework capable of inducing variable-length patterns from unannotated psychiatry web resources. The proposed framework can be divided into two parts: 1) a cognitive motivated model such as Hyperspace Analog to Language (HAL) and 2) an Evolutionary Inference Algorithm (EIA). The HAL model constructs a high-dimensional context space to represent words as well as combinations of words. Based on the HAL model, the EIA bootstraps with a small set of seed patterns, and then iteratively induces additional relevant patterns. To avoid moving in the wrong direction, the EIA further incorporates relevance feedback to guide the induction process. Experimental results indicate that combining the HAL model and relevance feedback enables the EIA to not only induce patterns from the unannotated web corpora, but also achieve useful results in a reasonable amount of time. The proposed framework thus significantly reduces reliance on annotated corpora.