Are object naming capacities affected in Parkinson’s Disease? Exploration of picture naming abilities and associated cognitive deficits

ABSTRACT

Background

The presence of naming difficulties in Parkinson’s Disease (PD), especially object naming difficulties, as well as the associated cognitive difficulties, remains a controversial topic.

Aims

This study assesses object naming capacities in PD patients and the cognitive impairment related to the patients,’ word naming difficulties, whether linguistic, executive or associated to slower cognitive processing speed.

Methods and Procedures

To that aim, 46 PD patients and 48 control participants were presented with a picture naming task of objects. Specific language difficulties were examined by analysing the naming errors, the effects of word frequency and length on naming performances, as well as the patients’ semantic performances in semantic matching and synonym judgment tasks. The executive assessment consisted of working memory, inhibition, flexibility and updating tasks, and cognitive processing speed was explored through an odd/even judgment task.

Outcomes and Results

The results show that PD patients have lower object naming scores. Regarding the associate cognitive impairment, the outcomes reveal that naming difficulties are related to updating difficulties and slower cognitive processing speed.

Conclusions

This study confirms the presence of object naming difficulties in PD. Moreover, the relationships between naming difficulties and executive deficits as well as slower processing speed are in line with many studies that also indicate relationships between executive dysfunction or slower processing speed and language difficulties in PD, but for other tasks.

KEYWORDS:

• Parkinson’s disease
• object naming difficulties
• picture naming task
• executive functions
• cognitive processing speed

Supplementary data

Supplemental data for this article can be accessed here

Acknowledgments

We thank Dr S. Majerus, Dr M. Poncelet and Dr P. Quinette for lending some of the materials required for the investigation. We thank Beverley Vanderkimpen, Caroline Dambroise and Victoria Souris for their help with the data collection. And we thank Pr. Nespoulous for his wise and relevant advice.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1. The aim of our study was to analyse the participants’ level of linguistic breakdown within the language system using a classical analysis of the effects of psycholinguistic variables, naming errors and phonological cueing. However, we cannot exclude the possible influence of the executive functions on these patterns of performance (Kaushanskaya & Crespo, 2019; Larson et al., 2020; Martin & Allen, 2008).

2. For the analysis of correct naming latencies, the assumption of normality was not met for score distributions. Therefore, the analyses were also run using nonparametric Mann-Whitney U tests, leading to an identical outcome of results.

3. For the cognitive processing speed and the flexibility tasks, the assumption of normality was not met for score distributions. Therefore, the analyses were also run using nonparametric Mann-Whitney U tests, leading to an identical outcome of results.

4. Given that the assumption of normality was not met for distributions of some results, the correlation analyses were also run using non-parametric Spearman correlations, leading to an identical outcome of results.

5. In this article, the variable “age” was not included in the regressions analyses as this was included in the studies of Altmann and Troche (2011) or Smith et al. (2018) because in our study, the participants’ age did not correlate with the results in the picture naming task.