Functional blindsight and its diagnosis

Front Neurol. 2024 Feb 7:15:1207115. doi: 10.3389/fneur.2024.1207115. eCollection 2024.


Even when brain scans fail to detect a striate lesion, functional evidence for blindsight can be adduced. In the aftermath of an automobile accident, JK became blind. Results of ophthalmic exams indicated that the blindness must be cortical. Nevertheless, multiple MRI scans failed to detect structural damage to the striate cortex. Prior to the accident JK had been an athlete; after the accident he retained some athletic abilities, arousing suspicions that he might be engaged in fraud. His residual athletic abilities-e.g., hitting a handball or baseball, or catching a Frisbee-coupled with his experienced blindness, suggested blindsight. But due to the apparent absence of striate lesions, we designed a series of tasks for temporal and spatial dimensions in an attempt to detect functional evidence of his disability. Indeed, test results revealed compelling neural evidence that comport with his subjective reports. This spatiotemporal task-related method that includes contrasts with healthy controls, and detailed understanding of the patient's conscious experience, can be generalized for clinical, scientific and forensic investigations of blindsight.

Keywords: P300; Riddoch Syndrome; akinetopsia; blindsight; consciousness; fMRI; hypercapnia challenge; self-relatedness.

Grants and funding

Support for TL's research was provided by funding from Taiwan Ministries of Health and Welfare, Education, and Science and Technology, as well as from the National Science and Technology Council (105-2410-H-038-004-MY1, 106-2410-H-038-003-MY3, 109-2410-H-038-009, 111-2410-H-038-012, DP2-110-21121-01-N-07-01, DP2-111-21121-01-N-05-01, 110IIT-03, and 111TMU-SHH-22). Support for CW's research was provided by the Higher Education Sprout Project of the Taiwan Ministry of Education (DP2-TMU-112-N-10) and the National Science and Technology Council (112-2314-B-038-044-MY3). Support for PT's research was provided by National Science and Technology Council (109-2423-H-038-001-MY4 and 112-2410-H-002-252).