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Enhancement and suppression in a lexical interference fMRI-paradigm.

Abel S, Dressel K, Weiller C, Huber W - Brain Behav (2012)

Bottom Line: Associatively and phonologically related distractors speeded responses (facilitation), while categorically related distractors slowed them down (inhibition) compared to UNREL.As a result, (A) reduced brain activations indeed resembled previously reported patterns of neural priming.Overlapping areas associated with conceptual priming were found for facilitatory distractors (inferior frontal gyri), and areas related to phonetic/articulatory processing (precentral gyri and left parietal operculum/insula) for distractors sharing feature overlap.

View Article: PubMed Central - PubMed

ABSTRACT
Previous picture-word interference (PWI) fMRI-paradigms revealed ambiguous mechanisms underlying facilitation and inhibition in healthy subjects. Lexical distractors revealed increased (enhancement) or decreased (suppression) activation in language and monitoring/control areas. Performing a secondary examination and data analysis, we aimed to illuminate the relation between behavioral and neural interference effects comparing target-related distractors (REL) with unrelated distractors (UNREL). We hypothesized that interference involves both (A) suppression due to priming and (B) enhancement due to simultaneous distractor and target processing. Comparisons to UNREL should remain distractor unspecific even at a low threshold. (C) Distractor types with common characteristics should reveal overlapping brain areas. In a 3T MRI scanner, participants were asked to name pictures while auditory words were presented (stimulus onset asynchrony [SOA] = -200 msec). Associatively and phonologically related distractors speeded responses (facilitation), while categorically related distractors slowed them down (inhibition) compared to UNREL. As a result, (A) reduced brain activations indeed resembled previously reported patterns of neural priming. Each target-related distractor yielded suppressions at least in areas associated with vision and conflict/competition monitoring (anterior cingulate cortex [ACC]), revealing least priming for inhibitors. (B) Enhancements concerned language-related but distractor-unspecific regions. (C) Some wider brain regions were commonly suppressed for combinations of distractor types. Overlapping areas associated with conceptual priming were found for facilitatory distractors (inferior frontal gyri), and areas related to phonetic/articulatory processing (precentral gyri and left parietal operculum/insula) for distractors sharing feature overlap. Each distractor with semantic relatedness revealed nonoverlapping suppressions in lexical-phonological areas (superior temporal regions). To conclude, interference combines suppression of areas well known from neural priming and enhancement of language-related areas caused by dual activation from target and distractor. Differences between interference and priming need to be taken into account. The present interference paradigm has the potential to reveal the functioning of word-processing stages, cognitive control, and responsiveness to priming at the same time.

No MeSH data available.


Related in: MedlinePlus

Areas of significant brain activation (conjunction , threshold at uncorrected P < 0.001, masked with first term at uncorrected P < 0.05) representing the processing of (a) facilitative distractors and (b) distractors with feature overlap, rendered onto the lateral and medial surface of a standard brain (see also Table 4).
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fig05: Areas of significant brain activation (conjunction , threshold at uncorrected P < 0.001, masked with first term at uncorrected P < 0.05) representing the processing of (a) facilitative distractors and (b) distractors with feature overlap, rendered onto the lateral and medial surface of a standard brain (see also Table 4).

Mentions: In order to reveal the communalities between related distractors in comparison to the unrelated distractor, we present results of the conjunction analyses in Figure 5 (Table 4). We present the peaks of activation. There was joint enhancement (14 voxels only) for both facilitatory conditions (P > U + A > U) in left inferior parietal lobule (BA 40). However, there was no common enhancement for the two conditions sharing feature overlap (P > U + C > U) or semantic relationships (A > U + C > U). Regarding communalities in repetition suppression, combining the two conditions featuring facilitation revealed a signal decrease in right inferior occipital gyrus (BA 19) and pre-SMA/ACC (BA 32). In the left hemisphere, activation in middle occipital gyrus, more anterior ACC (BA 32), and to a minor extent in parahippocampal gyrus (BA 20) were reduced. Moreover, bilateral IFG/insula were involved. For the two conditions sharing feature overlap, there was a joint decrease of activation in left LG (BA 18), parietal operculum/insula, and to a minor extent ACC (BA 32). Moreover, there were right hemisphere suppressions in cuneus (BA 18), precentral gyrus (BA 4), medial temporal/middle occipital gyrus, and to a minor extent in right thalamus and left precentral gyrus (BA 4). Finally, a minor signal decrease for the two conditions featuring semantic relationships was found in right medial temporal/middle occipital gyrus. The same small cluster was commonly suppressed for all distractor types, while there was no jointly enhanced brain region for them.


Enhancement and suppression in a lexical interference fMRI-paradigm.

Abel S, Dressel K, Weiller C, Huber W - Brain Behav (2012)

Areas of significant brain activation (conjunction , threshold at uncorrected P < 0.001, masked with first term at uncorrected P < 0.05) representing the processing of (a) facilitative distractors and (b) distractors with feature overlap, rendered onto the lateral and medial surface of a standard brain (see also Table 4).
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Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3345356&req=5

fig05: Areas of significant brain activation (conjunction , threshold at uncorrected P < 0.001, masked with first term at uncorrected P < 0.05) representing the processing of (a) facilitative distractors and (b) distractors with feature overlap, rendered onto the lateral and medial surface of a standard brain (see also Table 4).
Mentions: In order to reveal the communalities between related distractors in comparison to the unrelated distractor, we present results of the conjunction analyses in Figure 5 (Table 4). We present the peaks of activation. There was joint enhancement (14 voxels only) for both facilitatory conditions (P > U + A > U) in left inferior parietal lobule (BA 40). However, there was no common enhancement for the two conditions sharing feature overlap (P > U + C > U) or semantic relationships (A > U + C > U). Regarding communalities in repetition suppression, combining the two conditions featuring facilitation revealed a signal decrease in right inferior occipital gyrus (BA 19) and pre-SMA/ACC (BA 32). In the left hemisphere, activation in middle occipital gyrus, more anterior ACC (BA 32), and to a minor extent in parahippocampal gyrus (BA 20) were reduced. Moreover, bilateral IFG/insula were involved. For the two conditions sharing feature overlap, there was a joint decrease of activation in left LG (BA 18), parietal operculum/insula, and to a minor extent ACC (BA 32). Moreover, there were right hemisphere suppressions in cuneus (BA 18), precentral gyrus (BA 4), medial temporal/middle occipital gyrus, and to a minor extent in right thalamus and left precentral gyrus (BA 4). Finally, a minor signal decrease for the two conditions featuring semantic relationships was found in right medial temporal/middle occipital gyrus. The same small cluster was commonly suppressed for all distractor types, while there was no jointly enhanced brain region for them.

Bottom Line: Associatively and phonologically related distractors speeded responses (facilitation), while categorically related distractors slowed them down (inhibition) compared to UNREL.As a result, (A) reduced brain activations indeed resembled previously reported patterns of neural priming.Overlapping areas associated with conceptual priming were found for facilitatory distractors (inferior frontal gyri), and areas related to phonetic/articulatory processing (precentral gyri and left parietal operculum/insula) for distractors sharing feature overlap.

View Article: PubMed Central - PubMed

ABSTRACT
Previous picture-word interference (PWI) fMRI-paradigms revealed ambiguous mechanisms underlying facilitation and inhibition in healthy subjects. Lexical distractors revealed increased (enhancement) or decreased (suppression) activation in language and monitoring/control areas. Performing a secondary examination and data analysis, we aimed to illuminate the relation between behavioral and neural interference effects comparing target-related distractors (REL) with unrelated distractors (UNREL). We hypothesized that interference involves both (A) suppression due to priming and (B) enhancement due to simultaneous distractor and target processing. Comparisons to UNREL should remain distractor unspecific even at a low threshold. (C) Distractor types with common characteristics should reveal overlapping brain areas. In a 3T MRI scanner, participants were asked to name pictures while auditory words were presented (stimulus onset asynchrony [SOA] = -200 msec). Associatively and phonologically related distractors speeded responses (facilitation), while categorically related distractors slowed them down (inhibition) compared to UNREL. As a result, (A) reduced brain activations indeed resembled previously reported patterns of neural priming. Each target-related distractor yielded suppressions at least in areas associated with vision and conflict/competition monitoring (anterior cingulate cortex [ACC]), revealing least priming for inhibitors. (B) Enhancements concerned language-related but distractor-unspecific regions. (C) Some wider brain regions were commonly suppressed for combinations of distractor types. Overlapping areas associated with conceptual priming were found for facilitatory distractors (inferior frontal gyri), and areas related to phonetic/articulatory processing (precentral gyri and left parietal operculum/insula) for distractors sharing feature overlap. Each distractor with semantic relatedness revealed nonoverlapping suppressions in lexical-phonological areas (superior temporal regions). To conclude, interference combines suppression of areas well known from neural priming and enhancement of language-related areas caused by dual activation from target and distractor. Differences between interference and priming need to be taken into account. The present interference paradigm has the potential to reveal the functioning of word-processing stages, cognitive control, and responsiveness to priming at the same time.

No MeSH data available.


Related in: MedlinePlus