359
Views
17
CrossRef citations to date
0
Altmetric
Articles

Speed of processing and executive functions in adults with phenylketonuria: Quick in finding the word, but not the ladybird

, , &
Pages 171-198 | Received 28 Sep 2016, Accepted 10 Apr 2017, Published online: 20 Jun 2017
 

ABSTRACT

A reduction in processing speed is widely reported in phenylketonuria (PKU), possibly due to white matter pathology. We investigated possible deficits and their relationships with executive functions in a sample of 37 early-treated adults with PKU (AwPKUs). AwPKUs were not characterized by a generalized speed deficit, but instead their performance could be explained by two more specific impairments: (a) a deficit in the allocation of visuo-spatial attention that reduced speed in visual search tasks, in some reading conditions and visuo-motor coordination tasks; and (b) a more conservative decision mechanism that slowed down returning an answer across domains. These results suggest that the impairments in executive functions seen in AwPKUs are not the consequence of a generalized speed deficit. They also suggest that processing speed is linked to the efficiency of a particular cognitive component and cannot be considered a general function spanning domains. Similarities with patterns in ageing are discussed.

Acknowledgements

We thank Tarekegn Geberhiwot for allowing access to the patients.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1 It is to be noted that AwPKUs show no deficits in tasks tapping phonological awareness—such as spoonerisms and phoneme deletion tasks—excluding an alternative account for difficulties in non-word reading (see Palermo et al., Citation2017).

Additional information

Funding

This research was supported by a Marie Curie Intra European Fellowship within the 7th European Community Framework Programme granted to Liana Palermo under the supervision of Cristina Romani (TREPAPHEN; Project ID: 329423).

Log in via your institution

Log in to Taylor & Francis Online

PDF download + Online access

  • 48 hours access to article PDF & online version
  • Article PDF can be downloaded
  • Article PDF can be printed
USD 53.00 Add to cart

Issue Purchase

  • 30 days online access to complete issue
  • Article PDFs can be downloaded
  • Article PDFs can be printed
USD 509.00 Add to cart

* Local tax will be added as applicable

Related Research

People also read lists articles that other readers of this article have read.

Recommended articles lists articles that we recommend and is powered by our AI driven recommendation engine.

Cited by lists all citing articles based on Crossref citations.
Articles with the Crossref icon will open in a new tab.