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One-trial perceptual learning in the absence of conscious remembering and independent of the medial temporal lobe.
- Source :
-
Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2021 May 11; Vol. 118 (19). - Publication Year :
- 2021
-
Abstract
- A degraded, black-and-white image of an object, which appears meaningless on first presentation, is easily identified after a single exposure to the original, intact image. This striking example of perceptual learning reflects a rapid (one-trial) change in performance, but the kind of learning that is involved is not known. We asked whether this learning depends on conscious (hippocampus-dependent) memory for the images that have been presented or on an unconscious (hippocampus-independent) change in the perception of images, independently of the ability to remember them. We tested five memory-impaired patients with hippocampal lesions or larger medial temporal lobe (MTL) lesions. In comparison to volunteers, the patients were fully intact at perceptual learning, and their improvement persisted without decrement from 1 d to more than 5 mo. Yet, the patients were impaired at remembering the test format and, even after 1 d, were impaired at remembering the images themselves. To compare perceptual learning and remembering directly, at 7 d after seeing degraded images and their solutions, patients and volunteers took either a naming test or a recognition memory test with these images. The patients improved as much as the volunteers at identifying the degraded images but were severely impaired at remembering them. Notably, the patient with the most severe memory impairment and the largest MTL lesions performed worse than the other patients on the memory tests but was the best at perceptual learning. The findings show that one-trial, long-lasting perceptual learning relies on hippocampus-independent (nondeclarative) memory, independent of any requirement to consciously remember.<br />Competing Interests: The authors declare no competing interest.
- Subjects :
- Adult
Aged
Aged, 80 and over
Amnesia physiopathology
Female
Hippocampus physiopathology
Humans
Male
Memory Disorders physiopathology
Middle Aged
Photic Stimulation
Psychomotor Performance physiology
Temporal Lobe physiopathology
Consciousness physiology
Hippocampus physiology
Learning physiology
Memory physiology
Mental Recall physiology
Temporal Lobe physiology
Subjects
Details
- Language :
- English
- ISSN :
- 1091-6490
- Volume :
- 118
- Issue :
- 19
- Database :
- MEDLINE
- Journal :
- Proceedings of the National Academy of Sciences of the United States of America
- Publication Type :
- Academic Journal
- Accession number :
- 33952702
- Full Text :
- https://doi.org/10.1073/pnas.2104072118