Eye movements as probes of lexico-semantic processing in a patient with primary progressive aphasia

Abstract

Eye movement trajectories during a verbally cued object search task were used as probes of lexico-semantic associations in an anomic patient with primary progressive aphasia. Visual search was normal on trials where the target object could be named but became lengthy and inefficient on trials where the object failed to be named. The abnormality was most profound if the noun denoting the object could not be recognized. Even trials where the name of the target object was recognized but not retrieved triggered abnormal eye movements, demonstrating that retrieval failures can have underlying associative components despite intact comprehension of the corresponding noun.

Keywords:

• eye movements
• aphasia
• anterior temporal lobe
• single-word comprehension
• object naming

Acknowledgments

We would like to thank Joseph Boyle, Chancelor Cim, Adam Martersteck, Christina Wieneke, Kristen Whitney, Amanda Rezutek, and Brittany Lapin for help with assessment and analysis.

Additional information

Funding

This work was supported by NIH/NIA P30 AG13854, NIH/NINDS R01 NS075075 and NIH/NIDCD R01 DC008552. Additional support for M.S. was provided by the Turkish Education Foundation. Additional support for R.S.H. was provided by the Northwestern University Mechanisms of Aging and Dementia Training Grant [NIH/NIA T32 AG20506].