Processing complex pseudo-words in mild cognitive impairment: The interaction of preserved morphological rule knowledge with compromised cognitive ability

Abstract

Mild cognitive impairment (MCI) affects the cognitive performance of elderly adults. However, the level of severity is not high enough to be diagnosed with dementia. Previous research reports subtle language impairments in individuals with MCI specifically in domains related to lexical meaning. The present study used both off-line (grammaticality judgment) and on-line (lexical decision) tasks to examine aspects of lexical processing and how they are affected by MCI. 21 healthy older adults and 23 individuals with MCI saw complex pseudo-words that violated various principles of word formation in Slovenian and decided if each letter string was an actual word of their language. The pseudo-words ranged in their degree of violability. A task effect was found, with MCI performance to be similar to that of healthy controls in the off-line task but different in the on-line task. Overall, the MCI group responded slower than the elderly controls. No significant differences were observed in the off-line task, while the on-line task revealed a main effect of Violation type, a main effect of Group and a significant Violation × Group interaction reflecting a difficulty for the MCI group to process pseudo-words in real time. That is, while individuals with MCI seem to preserve morphological rule knowledge, they experience additional difficulties while processing complex pseudo-words. This was attributed to an executive dysfunction associated with MCI that delays the recognition of ungrammatical formations.

Prefix Stripping Re-Re-Revisited: MEG Investigations of Morphological Decomposition and Recomposition

“…The other noteworthy result was the failure to find the expected pattern for response times and acceptance rates for the re- violation items. While all the other experiments using a similar affixation violation-type manipulation consistently find that grammatical category violations are rejected more robustly, and more quickly, than argument structure violations, in Greek (Manouilidou, 2007; Manouilidou and Stockall, 2014; Neophytou et al, 2018), English (Manouilidou and Stockall, 2014), and Slovenian (Manouilidou et al, 2016), no such effect is found for the re- prefixed items in the current experiment. This null effect is not a mere absence of a statistically significant effect attributable to noisy data (the SDs in the re- conditions were similar to those for the other prefixes), but the genuine absence of any hint of a difference between the two violation conditions in acceptance rate, and a trend to an opposite direction pattern in the response time.…”

Changes in the Rhythm of Speech Difference between People with Nondegenerative Mild Cognitive Impairment and with Preclinical Dementia

“…Weiner et al [5] have found a close correlation between the severity of dementia and different linguistic metrics; nevertheless, the results in studies with patients in the mild-tomoderate stages of AD [6,7] cannot be generalized to earlier stages of the disease when compensatory abilities may result in more subtle impairments in functional language [8]. However, specific studies involving people with MCI have identified subtle language deficits [9] in tasks involving the naming of images and semantic tests, which are usually reflected in problems finding the right word in a given situation [10], changes in the frequency of words used for more common words [11], temporal changes in spontaneous language [3] with deficits in verbal fluency tasks [12], and phonemic paraphasia due to the difficulty in producing speech sounds in the right order [13].…”

Identification of Mild Cognitive Impairment From Speech in Swedish Using Deep Sequential Neural Networks

“…The fact that language impairment occurs early and commonly in the progression of AD, motivated many researchers to identify markers of language impairment in MCI. For example, Manouilidou et al ( 31 ) showed that while MCI individuals preserve morphological rule knowledge, they face processing difficulties of pseudo-words (for a discussion and review of current studies, see 32 , 33 ). As there is only a handful of studies on the acoustic properties of MCI speech (e.g., 30 , 34 ), more research on speech acoustics is required to gain a better understanding of how MCI speech differs from that of healthy controls.…”