Jason Bohan

Anomalies at the borderline of awareness: An erp study

Behaviorally, some semantic anomalies, such as those used to demonstrate N400 effects in ERPs, are easy to detect. However, some, such as “after an air crash, where should the survivors be buried?” are difficult. The difference has to do with the extent to which the anomalous word fits the general context. We asked whether anomalies that are missed elicit an ERP that could be taken as indicating unconscious recognition, and whether both types elicit an N400 effect when they are detected. We found that difficult anomalies having a good fit to general context did not produce an N400 effect, whereas control “easy-to-detect” anomalies did. For difficult anomalies, there was no evidence for unconscious detection occurring. The results support a qualitative distinction in the way the two types of anomalies are processed, and the idea that semantic information is simply not utilized (shallow processing) when difficult anomalies are missed.

Semantic anomalies at the borderline of consciousness : An eye-tracking investigation

We report an eye-tracking study in which participants read passages containing difficult-to-detect semantic anomalies. Would there be any evidence of the registration of the anomaly within the comprehension system (reflected in eye tracking) when anomalies were not noticed? Using early and late processing measures, there was no evidence for registration independent of conscious detection. Comparisons were made between detected and undetected anomalies and between these and nonanomalous controls. There was evidence of disruption to the tracking measures only when a conscious report was also made. These data fit the view that shallow semantic processing underlies the failure to detect anomalies. Implications for language processing are discussed.

The processing of good-fit semantic anomalies: an ERP investigation.

The failure-to-detect good-fit semantic anomalies is taken as evidence for shallow semantic processing, however the cognitive mechanisms involved are not well understood. To investigate this we recorded event-related potentials (ERPs) to sentences that contained good and poor-fit semantic anomalies and non-anomalous controls. Detected good-fit anomalies elicited an N400 effect when detection accuracy was stressed, indicating the registration of the anomaly. ERP analyses further ruled out that anomaly non-/detection is due to differences in initial word encoding or in processing prior contextual information. In addition, starting in the P2 interval, the ERP waveform was less positive for non-detected than detected anomalies and non-anomalous controls, presumably reflecting a language-driven modulation of visual input processing. And finally, detection of good-fit anomalies may also depend on the integration of sentential information into the discourse model at the end of the critical sentence. Overall, present findings support the shallow processing account of anomaly detection failure.

Perspective Effects During Reading: Evidence from Text Change-Detection

ABSTRACT We report two text change-detection studies in which we investigate the influence of reading perspective on text memory. In Experiment 1 participants read from the perspective of one of two characters in a series of short stories, and word changes were either semantically close or distant. Participants correctly reported more changes to perspective-relevant than perspective-irrelevant words and for distant than close changes. However, distance and perspective did not interact, suggesting that adopting a particular perspective did not lead to a more fine-grained analysis of perspective-relevant information. In Experiment 2 participants read one long narrative from the perspective of either a burglar or house-buyer. Results showed that only participants with a low working memory span showed perspective effects, suggesting that individual differences in working memory capacity appear to influence processing of perspective-relevant information.