The naming profile in Alzheimer patients parallels that of elderly controls

Abstract

Controversy exists as to whether semantic disruption in Alzheimer's disease (AD) systematically impairs the naming of living things. Moreover, little is known about performance across more specific subcategories. We investigated picture naming in 28 AD patients and 24 controls. To deal with nonnormal distributions, we created 1,000 bootstrap hierarchical regressions and determined which variables (the "nuisance" variables familiarity, word frequency, age of acquisition and visual complexity; category; and control naming) best predicted AD patient naming. Nuisance variables combined, control naming, and category uniquely accounted for 39%, 36%, and 3% of patient naming variance, respectively. Finally, analysis of the AD naming profile across the 10 subcategories mirrored that of controls. Taken together, these findings indicate that while AD naming is, of course, quantitatively worse than that of controls, it does not qualitatively differ-that is, it is an exaggerated normal profile.

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

“…Our results, showing the presence of category effects in all the participants, provide support for these notions. In addition, the fact that patients and NC both presented category effects lends support to the view that LT/NLT differences between both populations are only quantitative but not qualitative in essence [ 14 , 16 – 21 ].…”

“…Our results support this view: despite the fact that domain was a significant predictor for all the groups, its impact was comparatively inferior to that of NVs. In this regard, recent studies with AD patients have claimed that NVs are better naming predictors than domain [ 16 , 17 ]; some researchers even reported NVs to be the only significant predictors regardless of domain [ 22 ]. Apart from supporting this view, our study extends this conclusion from AD patients to healthy participants.…”

“…At present, the existence of this phenomenon in AD is strongly debated. Although seminal studies reported category effects in AD [ 15 ], current works suggest these effects are rare [ 14 , 16 – 22 ]. Thus, in their meta-analytic review, Laws et al [ 14 ] found more reports of LT deficits (i.e., the more commonly reported outcome); however these last ones were in fact no larger—in terms of effect size—than the loss associated with NLT naming.…”

“…For example, a study by Tippett et al [ 22 ] found that NVs accounted for 25 and 40% of naming variance of NC and AD patients, respectively; alternatively, domain (in their study, category) was not a significant predictor in any group. Gale et al [ 16 ] found that, compared to domain, NVs explained threefold naming variance in AD patients (33% versus 11%). This imbalance was even more noticeable in a longitudinal study by our group: up to 71% for NVs versus about 8% for domain [ 17 ].…”

Seres vivos y artefactos: ¿efectos categoriales producto de la ausencia de color en tareas de denominación de dibujos?

“…Muchos motivos llevaron a esta discusión. Por ejemplo, Gale et al (Gale, Irvine, Laws & Ferrissey, 2008) compararon el desempeño de un grupo de controles y pacientes con enfermedad de Alzheimer en una tarea de denominación y encontraron que ambos grupos presentaban un perfil de desempeño similar, denominaban mejor la categoría de partes del cuerpo (frecuentemente incluida en el dominio de SV) y peor la de instrumentos musicales (frecuentemente incluida en el de ART). Asimismo, otros investigadores describieron casos de pacientes con dificultades para el procesamiento de SV que conservaban el procesamiento de partes del cuerpo en tanto que la categoría de instrumentos musicales se alteraba (Capitani, Laiacona, Mahon & Caramazza, 2003).…”