Biomedical subjects

M van Turennout

Publications and source records attributed to M van Turennout.

3 recordsLinked to original sources

PubMed2000

Long-lasting cortical plasticity in the object naming system.

A single exposure to an object can produce long-lasting behavioral change. Here, using event-related functional magnetic resonance imaging (fMRI), we provide evidence for long-lasting changes in cortical activity associated with perceiving and naming objects. In posterior regions, we observed an immediate (30-second) and long-lasting (3-day) decrease in neural activity after brief (200-ms) exposure to nameable and nonsense objects. In addition, slower-developing decreases in left inferior frontal activity were observed concurrently with increases in left insula activity, only for nameable objects. These time-dependent cortical changes may reflect two distinct learning mechanisms: the formation of sparser, yet more object-form-specific, representations in posterior regions, and experience-induced reorganization of the brain circuitry underlying lexical retrieval in anterior regions.

Cerebral Cortex↗

PubMed1999

The time course of grammatical and phonological processing during speaking: evidence from event-related brain potentials.

Motor-related brain potentials were used to examine the time course of grammatical and phonological processes during noun phrase production in Dutch. In the experiments, participants named colored pictures using a no-determiner noun phrase. On half of the trials a syntactic-phonological classification task had to be performed before naming. Depending on the outcome of the classifications, a left or a right push-button response was given (go trials), or no push-button response was given (no-go trials). Lateralized readiness potentials (LRPs) were derived to test whether syntactic and phonological information affected the motor system at separate moments in time. The results showed that when syntactic information determined the response-hand decision, an LRP developed on no-go trials. However, no such effect was observed when phonological information determined response hand. On the basis of the data, it can be estimated that an additional period of at least 40 ms is needed to retrieve a word's initial phoneme once its lemma has been retrieved. These results provide evidence for the view that during speaking, grammatical processing precedes phonological processing in time.

Brain↗

PubMed1997

Electrophysiological evidence on the time course of semantic and phonological processes in speech production.

The temporal properties of semantic and phonological processes in speech production were investigated in a new experimental paradigm using movement-related brain potentials. The main experimental task was picture naming. In addition, a 2-choice reaction go/no-go procedure was included, involving a semantic and a phonological categorization of the picture name. Lateralized readiness potentials (LRPs) were derived to test whether semantic and phonological information activated motor processes at separate moments in time. An LRP was only observed on no-go trials when the semantic (not the phonological) decision determined the response hand. Varying the position of the critical phoneme in the picture name did not affect the onset of the LRP but rather influenced when the LRP began to differ on go and no-go trials and allowed the duration of phonological encoding of a word to be estimated. These results provide electrophysiological evidence for early semantic activation and later phonological encoding.

Adult↗