Investigation into olfactory memory in unique amnesia

Section A
Section A presents a systematic literature search and narrative synthesis of the literature on long-term olfactory recognition memory in a healthy adult human population. Searches produced 18 studies, which were subject to quality appraisals. Results revealed that olfactory recognition memory was not persistent over time but rather declined due to increased false alarm rates. Studies largely employed forced-choice and alternative forced-choice recognition tasks in investigating olfactory recognition memory. Several covariates influencing the recall of odours were also identified. Overall findings deviated from previous literature but may be reflective of the limitations of this current review. Clinical implications and directions for future research are discussed.

Section B
Section B presents an observational case-control study. A clinical participant with unique, medically unexplained amnesia (SI) was compared to eight age and education-matched controls for performance on tests of olfactory recognition memory, implicit skills (mirror maze task), and a neuropsychological test battery (Short Parallel Assessments of Neuropsychology Status [SPANS]). SI performed at a similar level to control participants within his memory retention window of 1 waking-day, but by day 2 of testing (unlike controls) SI did not demonstrate any retained learning. Clinical implications and future directions for research are discussed.