The naming impairment of living and nonliving items in Alzheimer's disease

Abstract

Several studies of semantic abilities in Dementia of the Alzheimer Type (DAT) suggest that their semantic disorders may affect specific categories of knowledge. In particular, the existence of a category-specific semantic impairment affecting, selectively, living things has frequently been reported in association with DAT. We report here results from two naming tasks of 25 DAT patients and two subgroups within this population. The first naming task used 48 black and white line drawings from Snodgrass and Vanderwart (1980) which controlled the visual complexity of stimuli from living and nonliving categories. The second task used 44 colored pictures (to assess the influence of word frequency in living vs. nonliving categories). Within the set of black and white pictures, both DAT patients and controls obtained significantly lower scores on high visual complexity stimuli than on stimuli of low visual complexity. A clear effect of semantic category emerged for DAT patients and controls, with a lower performance on the living category. Within the colored set, pictures corresponding to high frequency words gave rise to significantly higher scores than pictures corresponding to low frequency words. No significant difference emerged between living versus nonliving categories, either in DAT patients or in controls. In the two tasks, the two subgroups of DAT patients presented a different profile of performance and error type. As color constitutes the main difference between the two sets of pictures, our results point to the relevance of this cue in the processing of semantic information, with visual complexity and frequency also being very relevant. (JINS, 1995, /, 39-48.)

On Colour, Category Effects, and Alzheimer’s Disease: A Critical Review of Studies and Further Longitudinal Evidence

“…As aforementioned, some of these discrepancies could have a methodological basis. In keeping with previous works, in our study, AD patients and NC both benefit from colour [ 23 – 25 ]. The regression analyses illustrate that the influence of domain mildly decreases in all the participants when they named colour with respect to greyscale items.…”

“…This means that all of our participants slightly improved the naming of LT coloured items with respect to greyscale ones. However, differentially to studies reporting the disappearance of category effects when AD patients named LT colour items [ 23 – 25 ], in our study, category effects persisted in all the groups; in other words, the improvement derived from adding colour was insufficient to balance the LT/NLT disparity. Consequently, as the absence of ceiling effects is the most significant dissimilarity between our study and the above-mentioned studies, we postulate that this could be the essential point: it is possible that NC would have shown the same LT/NLT disparity with no ceiling effects present.…”

On Colour, Category Effects, and Alzheimer’s Disease: A Critical Review of Studies and Further Longitudinal Evidence

“…As aforementioned, some of these discrepancies could have a methodological basis. In keeping with previous works, in our study, AD patients and NC both benefit from colour [ 23 – 25 ]. The regression analyses illustrate that the influence of domain mildly decreases in all the participants when they named colour with respect to greyscale items.…”

“…This means that all of our participants slightly improved the naming of LT coloured items with respect to greyscale ones. However, differentially to studies reporting the disappearance of category effects when AD patients named LT colour items [ 23 – 25 ], in our study, category effects persisted in all the groups; in other words, the improvement derived from adding colour was insufficient to balance the LT/NLT disparity. Consequently, as the absence of ceiling effects is the most significant dissimilarity between our study and the above-mentioned studies, we postulate that this could be the essential point: it is possible that NC would have shown the same LT/NLT disparity with no ceiling effects present.…”

Categorization of novel animals by patients with Alzheimer's disease and corticobasal degeneration.

“…AD patients' success at rejecting unrelated foils on the semantic decision task suggests that sufficient object knowledge is retained for using similarity-based processes to distinguish among familiar but unrelated categories. Although we cannot rule out some degraded feature knowledge in AD (Chertkow et al, 1990; Garrard et al, 1998; Garrard et al, 2001; Gonnerman et al, 1997; Montanes, Goldblum & Boller, 1995; Montanes et al, 1996; Silveri et al, 1991), the observations in the present study suggest that a rule-based categorization deficit also contributes to AD patients' semantic memory difficulty.…”

Effects of structural similarity and name frequency on picture naming in Alzheimer's disease

“…The discrepancy with a previous finding of category-specific deficits in AD (Silveri et al, 1991) likely reflects a ceiling effect in the performance of control participants that may have obscured the finding that living things are more difficult to name. Montanes et al (1995) reported conflicting results about whether accuracy is lower for living things; however, our data are consistent with their apparent failure to find a disproportionate impairment in naming accuracy in AD patients.…”

On Colour, Category Effects, and Alzheimer’s Disease: A Critical Review of Studies and Further Longitudinal Evidence

“…As aforementioned, some of these discrepancies could have a methodological basis. In keeping with previous works, in our study, AD patients and NC both benefit from colour [ 23 – 25 ]. The regression analyses illustrate that the influence of domain mildly decreases in all the participants when they named colour with respect to greyscale items.…”

“…This means that all of our participants slightly improved the naming of LT coloured items with respect to greyscale ones. However, differentially to studies reporting the disappearance of category effects when AD patients named LT colour items [ 23 – 25 ], in our study, category effects persisted in all the groups; in other words, the improvement derived from adding colour was insufficient to balance the LT/NLT disparity. Consequently, as the absence of ceiling effects is the most significant dissimilarity between our study and the above-mentioned studies, we postulate that this could be the essential point: it is possible that NC would have shown the same LT/NLT disparity with no ceiling effects present.…”

Categorization of novel animals by patients with Alzheimer's disease and corticobasal degeneration.

“…AD patients' success at rejecting unrelated foils on the semantic decision task suggests that sufficient object knowledge is retained for using similarity-based processes to distinguish among familiar but unrelated categories. Although we cannot rule out some degraded feature knowledge in AD (Chertkow et al, 1990; Garrard et al, 1998; Garrard et al, 2001; Gonnerman et al, 1997; Montanes, Goldblum & Boller, 1995; Montanes et al, 1996; Silveri et al, 1991), the observations in the present study suggest that a rule-based categorization deficit also contributes to AD patients' semantic memory difficulty.…”

Effects of structural similarity and name frequency on picture naming in Alzheimer's disease

“…The discrepancy with a previous finding of category-specific deficits in AD (Silveri et al, 1991) likely reflects a ceiling effect in the performance of control participants that may have obscured the finding that living things are more difficult to name. Montanes et al (1995) reported conflicting results about whether accuracy is lower for living things; however, our data are consistent with their apparent failure to find a disproportionate impairment in naming accuracy in AD patients.…”

On Colour, Category Effects, and Alzheimer’s Disease: A Critical Review of Studies and Further Longitudinal Evidence

“…As aforementioned, some of these discrepancies could have a methodological basis. In keeping with previous works, in our study, AD patients and NC both benefit from colour [ 23 – 25 ]. The regression analyses illustrate that the influence of domain mildly decreases in all the participants when they named colour with respect to greyscale items.…”

“…This means that all of our participants slightly improved the naming of LT coloured items with respect to greyscale ones. However, differentially to studies reporting the disappearance of category effects when AD patients named LT colour items [ 23 – 25 ], in our study, category effects persisted in all the groups; in other words, the improvement derived from adding colour was insufficient to balance the LT/NLT disparity. Consequently, as the absence of ceiling effects is the most significant dissimilarity between our study and the above-mentioned studies, we postulate that this could be the essential point: it is possible that NC would have shown the same LT/NLT disparity with no ceiling effects present.…”

Categorization of novel animals by patients with Alzheimer's disease and corticobasal degeneration.

“…AD patients' success at rejecting unrelated foils on the semantic decision task suggests that sufficient object knowledge is retained for using similarity-based processes to distinguish among familiar but unrelated categories. Although we cannot rule out some degraded feature knowledge in AD (Chertkow et al, 1990; Garrard et al, 1998; Garrard et al, 2001; Gonnerman et al, 1997; Montanes, Goldblum & Boller, 1995; Montanes et al, 1996; Silveri et al, 1991), the observations in the present study suggest that a rule-based categorization deficit also contributes to AD patients' semantic memory difficulty.…”

Effects of structural similarity and name frequency on picture naming in Alzheimer's disease

“…The discrepancy with a previous finding of category-specific deficits in AD (Silveri et al, 1991) likely reflects a ceiling effect in the performance of control participants that may have obscured the finding that living things are more difficult to name. Montanes et al (1995) reported conflicting results about whether accuracy is lower for living things; however, our data are consistent with their apparent failure to find a disproportionate impairment in naming accuracy in AD patients.…”