Biomedical subjects

Kati Renvall

Publications and source records attributed to Kati Renvall.

4 recordsLinked to original sources

PubMed2006

Effectiveness of contextual repetition priming treatments for anomia depends on intact access to semantics.

Naming of two semantically impaired aphasic patients was treated with the contextual repetition priming technique, which involves repeated repetition of names of pictures that are related semantically, phonologically, or are unrelated. Our previous studies using this technique have suggested that patients with impaired access to lexical-semantic representations benefit in the short-term from this treatment technique, but show no long-term improvement in naming. In contrast, patients with good access to semantics show short- and long-term benefits from this treatment. Here we report two studies of treatment for two individuals with aphasia affecting access to lexical semantics and anomia but spared access to input and output phonology and spared conceptual semantics. We predicted that they would show short-term facilitation from the contextual priming, but no long-term improvements in naming. The results confirmed the prediction. An account of this pattern is offered within the framework of an interactive activation model of word retrieval. Additionally, we discuss alternative techniques for addressing naming deficits when access to semantics is impaired.

Adult↗

PubMed2005

Contextual priming in semantic anomia: a case study.

The present case continues the series of anomia treatment studies with contextual priming (CP), being the second in-depth treatment study conducted for an individual suffering from semantically based anomia. Our aim was to acquire further evidence of the facilitation and interference effects of the CP treatment on semantic anomia. Based on the results of the study of , our hypothesis before the treatment was that our participant would show short-term interference and at most modest and short-term benefit from treatment. To acquire such evidence would not only be important for the choice of anomia treatment methods in individual patients, but would also prompt further development of the CP method. The CP technique used for our participant included cycles of repeating and naming items in three contextual conditions (semantic, phonological, and unrelated). As predicted, the overall improvement of naming was modest and short-term. Interestingly, the contextual condition that corresponded with the nature of our patient's underlying naming deficit (semantic) elicited immediate interference in the form of contextual naming errors, as well as short-term improvement of naming. Based on this and a recent study by , it appears that despite short-term positive effects, in its current form the CP treatment is not sufficient for those aphasics who have a semantic deficit underlying their anomia. The possible mechanism and directions for future research are discussed.

Aged↗

PubMed2004

Learning new names for new objects: cortical effects as measured by magnetoencephalography.

We tracked the evolvement of naming-related cortical dynamics with magnetoencephalography when five normal adults successfully learned names and/or meanings of unfamiliar objects. In all subjects, the learning of new names was associated with pronounced cortical effects. The learning effect was of long latency and emerged as a change of activation in the same cortical network that was active during naming of familiar items. In four out of five subjects, the cortical learning effect occurred in the inferior parietal lobe. In three of these subjects, the cortical effect was left-sided. These results suggest that the inferior parietal lobe plays an important role in the acquisition of novel words, presumably as a part of working memory systems.

Adult↗

PubMed2003

Naming multiple objects: neural correlates as measured by positron emission tomography.

The aim of this study was to examine the neural substrates of multi-object naming by positron emission tomography in normals. Multi-object naming is used in a technique called contextual priming (CP) to elicit contextual effects on picture naming through systematic manipulation of the relatedness of to-be-named pictures in an array. Inhibitory and facilitatory effects of CP on naming have been used both to highlight the inner dynamics of the normal word retrieval system and to treat naming difficulties caused by acquired anomia. Because of the complexity of the CP technique, it is unclear whether it merely reflects lexical retrieval or whether it also recruits general cognitive resources such as attentional control and response selection to a significant degree. When compared with a baseline situation in which colored circles were named, multi-object naming elicited increased blood flow in the occipital lobe and in the left inferior temporal and fusiform gyri. These areas have been related to visual pattern recognition and semantic access, and the pattern of activation is in line with previous functional imaging studies on single picture naming. In conclusion, multi-object naming does not appear to activate brain regions beyond those needed for single object naming. These findings thus provide independent evidence for the claim that CP is a valid paradigm for the study of word production proper.

Adult↗