Sensory ratings and sensitivity to perceptual variables: Novel approach to evaluating semantic memory in mild cognitive impairment

Background: The lexical-semantic impairments at different levels of semantic processing are often observed in Mild cognitive impairment (MCI). To better understand the nature of the lexical-semantic impairment in MCI, this study included two experiments: a sensory rating task and a lexical decision task. Subjects and Methods: Twenty individuals diagnosed with MCI were recruited as well as eighty healthy subjects to serve as a control group. For the first time, the sensory ratings of words were collected in the MCI population and compared with ratings of the same words collected from the control population. Results: Furthermore, the MCI patients showed impaired performance related to executive functioning and preserved long-term memory-related performance. Unlike most studies that found semantic deficits, we were able to observe the highly preserved aspect of knowledge both in terms of semantic and episodic memory. Conclusion: Also, we showed that this knowledge could be exploited in visual word recognition, proposing further use of visual lexical decision task to investigate not only sublexical but also semantic variables in the clinical population.