Eye movements support the link between conscious memory and medial temporal lobe function

Memory consists of conscious and unconscious systems with different brain substrates. Eye movements are affected by past experience, but it is often unclear what kind of memory is involved. We examined the preferential viewing effect.

Article Abstract

“When individuals select the recently studied (and familiar) item in a multiple-choice memory test, they direct a greater proportion of viewing time toward the to-be-selected item when their choice is correct than when their choice is incorrect. Thus, for both correct and incorrect choices, individuals indicate that the chosen item is old, but viewing time nevertheless distinguishes between old and new items. What kind of memory supports this preferential viewing effect? We recorded eye movements while participants made three-alternative, forced-choice recognition memory judgments for scenes. In experiment 1 (n = 30), the magnitude of the preferential viewing effect was strongly correlated with measures of conscious, declarative memory: recognition accuracy as well as the difference in confidence ratings and in response times for correct and incorrect choices. In four analyses that minimized the contribution of declarative memory in order to detect a possible contribution from other processes, the preferential viewing effect was absent. In experiment 2, five memory-impaired patients with medial temporal lobe lesions exhibited a diminished preferential viewing effect. These patients also exhibited poor recognition accuracy and reduced differences in confidence ratings and response times for correct and incorrect choices. We propose that the preferential viewing effect is a phenomenon of conscious, declarative memory and is dependent on the medial temporal lobe. The findings support the link between medial temporal lobe function and declarative memory. When the effects of experience depend on the medial temporal lobe, the effects reflect conscious memory.

Significance: Memory consists of conscious and unconscious systems with different brain substrates. Eye movements are affected by past experience, but it is often unclear what kind of memory is involved. We examined the preferential viewing effect, whereby in multiple-choice tests of recognition memory, more viewing is directed toward an item that is about to be selected when the choice is correct than when the choice is incorrect. The magnitude of this effect was correlated with measures of conscious, declarative memory, was absent when declarative memory was minimized, and was diminished in memory-impaired patients with medial temporal lobe lesions. We propose that this eye movement effect is a phenomenon of conscious memory, supporting the link between conscious memory and medial temporal lobe function.”

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Article Access

Open Access

Urgolites, Z. J., Smith, C. N., & Squire, L. R. (2018). Eye movements support the link between conscious memory and medial temporal lobe function. Proceedings of the National Academy of Sciences of the USA, 115(29), 7599-7604. https://doi.org/10.1073/pnas.1803791115