Biomedical subjects

Sonja A Kotz

Publications and source records attributed to Sonja A Kotz.

At least 19 recordsLinked to original sources

PubMed2007

Role of the corpus callosum in speech comprehension: interfacing syntax and prosody.

The role of the corpus callosum (CC) in the interhemispheric interaction of prosodic and syntactic information during speech comprehension was investigated in patients with lesions in the CC, and in healthy controls. The event-related brain potential experiment examined the effect of prosodic phrase structure on the processing of a verb whose argument structure matched or did not match the prior prosody-induced syntactic structure. While controls showed an N400-like effect for prosodically mismatching verb argument structures, thus indicating a stable interplay between prosody and syntax, patients with lesions in the posterior third of the CC did not show this effect. Because these patients displayed a prosody-independent semantic N400 effect, the present data indicate that the posterior third of the CC is the crucial neuroanatomical structure for the interhemispheric interplay of suprasegmental prosodic information and syntactic information.

Adult↗

PubMed2006

Lesion-site affects grammatical gender assignment in German: perception and production data.

Two experiments investigated phonological, derivational-morphological and semantic aspects of grammatical gender assignment in a perception and a production task in German aphasic patients and age-matched controls. The agreement of a gender indicating adjective (feminine, masculine or neuter) and a noun was evaluated during perception in Experiment 1 (grammaticality judgment). In Experiment 2 the same participants had to produce the matching definite article to a noun. In the perception task patients with left frontal lesions (LF) made more errors during phonological gender assignment as compared to derivational-morphological and semantic gender assignment, while patients with lesions of the posterior superior temporal gyrus (pSTG) made more errors in derivational-morphological gender assignment as compared to phonological and semantic gender assignment. In the production task no differences between patient groups were found. These data support previous evidence that left frontal brain areas are critically involved in phonological processing. The pSTG on the other hand may be critically engaged in the integration of phonological and lexical information essential for phonological and derivational-morphological gender assignment.

Adult↗

PubMed2006

Is bilingual lexical access influenced by language context?

Using primed lexical decision, we measured reaction times and event-related brain potentials to targets that had German meanings (boss) of German-English interlingual homograph primes (chef). In an all-English experiment, we tested the effects of (1) global language context created by a first- or second-language film before the experiment, and (2) context over time, by analyzing the first and second experimental halves. We report significant reaction time and event-related potential priming of first-language meanings in the second-language experiment. The effects obtained despite block and context manipulations support and extend the nonselective access theory of bilingual word recognition.

Adolescent↗

PubMed2006

Beyond the right hemisphere: brain mechanisms mediating vocal emotional processing.

Vocal perception is particularly important for understanding a speaker's emotional state and intentions because, unlike facial perception, it is relatively independent of speaker distance and viewing conditions. The idea, derived from brain lesion studies, that vocal emotional comprehension is a special domain of the right hemisphere has failed to receive consistent support from neuroimaging. This conflict can be reconciled if vocal emotional comprehension is viewed as a multi-step process with individual neural representations. This view reveals a processing chain that proceeds from the ventral auditory pathway to brain structures implicated in cognition and emotion. Thus, vocal emotional comprehension appears to be mediated by bilateral mechanisms anchored within sensory, cognitive and emotional processing systems.

Affect↗

PubMed2006

Lateralization of emotional prosody in the brain: an overview and synopsis on the impact of study design.

Recently, research on the lateralization of linguistic and nonlinguistic (emotional) prosody has experienced a revival. However, both neuroimaging and patient evidence do not draw a coherent picture substantiating right-hemispheric lateralization of prosody and emotional prosody in particular. The current overview summarizes positions and data on the lateralization of emotion and emotional prosodic processing in the brain and proposes that: (1) the realization of emotional prosodic processing in the brain is based on differentially lateralized subprocesses and (2) methodological factors can influence the lateralization of emotional prosody in neuroimaging investigations. Latter evidence reveals that emotional valence effects are strongly right lateralized in studies using compact blocked presentation of emotional stimuli. In contrast, data obtained from event-related studies are indicative of bilateral or left-accented lateralization of emotional prosodic valence. These findings suggest a strong interaction between language and emotional prosodic processing.

Cerebral Cortex↗

PubMed2005

On the role of attention for the processing of emotions in speech: sex differences revisited.

In a previous cross-modal priming study [A. Schirmer, A.S. Kotz, A.D. Friederici, Sex differentiates the role of emotional prosody during word processing, Cogn. Brain Res. 14 (2002) 228-233.], we found that women integrated emotional prosody and word valence earlier than men. Both sexes showed a smaller N400 in the event-related potential to emotional words when these words were preceded by a sentence with congruous compared to incongruous emotional prosody. However, women showed this effect with a 200-ms interval between prime sentence and target word whereas men showed the effect with a 750-ms interval. The present study was designed to determine whether these sex differences prevail when attention is directed towards the emotional content of prosody and word meaning. To this end, we presented the same prime sentences and target words as in our previous study. Sentences were spoken with happy or sad prosody and followed by a congruous or incongruous emotional word or pseudoword. The interval between sentence offset and target onset was 200 ms. In addition to performing a lexical decision, participants were asked to decide whether or not a word matched the emotional prosody of the preceding sentence. The combined lexical and congruence judgment failed to reveal differences in emotional-prosodic priming between men and women. Both sexes showed smaller N400 amplitudes to emotionally congruent compared to incongruent words. This suggests that the presence of sex differences in emotional-prosodic priming depends on whether or not participants are instructed to take emotional prosody into account.

Adult↗

PubMed2005

Zooming into L2: global language context and adjustment affect processing of interlingual homographs in sentences.

In a semantic priming study, we investigated the processing of German-English homographs such as gift (German = "poison", English = "present") in sentence contexts using a joint reaction time (RT)/event-related brain potential (ERP) measure. Native German speakers with intermediate or advanced knowledge of English (N = 48) performed an all-L2 (English) experiment where sentences such as "The woman gave her friend an expensive gift" (control prime: item) were presented, followed by targets (i.e., boss) for lexical decision. To test the role of global task effects during sentence processing, we presented half the participants (N = 24) with a 20-min silent film narrated in German and half (N = 24) with the film in English before the experiment. To address the development of task effects over time, we analyzed the first and second blocks of the experiment. The results showed a significant interaction between semantic priming, movie version, and block in both the RTs and ERPs: there was significant semantic priming in the RTs and modulations in the N200 and N400 components only for participants who viewed the German movie, and only during the first block. Results suggest that in an all-L2 sentence task with L2 pre-task priming (English film), decision thresholds are raised high enough to eliminate measurable influence of the L1 on the L2. Despite identical material, participants who viewed the German film had to adjust, or zoom in, to the all-L2 task. Implications of this zooming in process in are discussed in terms of the recent Bilingual Interactive Activation (BIA+) model of bilingual word recognition [T. Dijkstra, W.J.B. Van Heuven, The architecture of the bilingual word recognition system: from identification to decision, Bilingualism: Lang. Cogn. 5 (2002) 175-197].

Adaptation, Psychological↗

PubMed2005

Who's in control? Proficiency and L1 influence on L2 processing.

We report three reaction time (RT)/event-related brain potential (ERP) semantic priming lexical decision experiments that explore the following in relation to L1 activation during L2 processing: (1) the role of L2 proficiency, (2) the role of sentence context, and (3) the locus of L1 activations (orthographic vs. semantic). All experiments used German (L1) homonyms translated into English (L2) to form prime-target pairs (pine-jaw for Kiefer) to test whether the L1 caused interference in an all-L2 experiment. Both RTs and ERPs were measured on targets. Experiment 1 revealed reversed priming in the N200 component and RTs for low-proficiency learners, but only RT interference for high-proficiency participants. Experiment 2 showed that once the words were processed in sentence context, the low-proficiency participants still showed reversed N200 and RT priming, whereas the high-proficiency group showed no effects. Experiment 3 tested native English speakers with the words in sentence context and showed a null result comparable to the high-proficiency group. Based on these results, we argue that cognitive control relating to translational activation is modulated by (1) L2 proficiency, as the early interference in the N200 was observed only for low-proficiency learners, and (2) sentence context, as it helps high-proficiency learners control L1 activation. As reversed priming was observed in the N200 and not the N400 component, we argue that (3) the locus of the L1 activations was orthographic. Implications in terms of bilingual word recognition and the functional role of the N200 ERP component are discussed.

Adult↗

PubMed2004

The neural correlates of grammatical gender decisions in Spanish.

In the current study, nine participants were asked to make gender decisions for a set of Spanish nouns while being scanned with functional MRI (fMRI). Words were chosen in which a direct mapping between ending and gender ("transparent" items such as carro(fem) or casa(masc)) is present and those in which there is not a direct relationship ("opaque" items such as fuente(fem) or arroz(masc)). Direct comparisons between opaque and transparent words revealed increased activity in left BA44/45, and BA44/6 as well as bilateral activation near BA 47/insula and the anterior cingulate gyrus. These results reveal activity in areas previously found to be devoted to articulation of the determiner and to morphological processing. Taken together they support the notion that gender decisions for opaque items requires deeper and more effortful processing during the retrieval of lexical and syntactic information.

Adult↗

PubMed2004

Pitch modulates lexical identification in spoken word recognition: ERP and behavioral evidence.

Event-related potentials (ERPs) were recorded in cross-modal word fragment priming (CMWP) to address the function of pitch for the identification of spoken words. In CMWP fragments of spoken words (e.g., re taken from Regal [Engl. shelves]) are immediately followed by visual targets. Together with reduced reaction times (RTs), an ERP deflection named P350 has been found to be reduced for targets, which match the primes (e.g., in the prime-target pair re-REGAL) as compared to unrelated targets (e.g., re-WIRBEL [Engl. burble]). The P350 has been related to facilitated lexical identification [Friedrich, Kotz, Friederici and Gunter (in press), ERPs reflect lexical identification in word fragment priming, JOCN]. In the present study, we presented syllable primes with different pitch contours. One version of each prime bore a stressed pitch contour (e.g., re_1), the other an unstressed pitch contour (e.g., re_2). Primes were combined with targets being either stressed on the first syllable (e.g., REgel [Engl. rule]) or on the second syllable (e.g., reGAL [Engl. shelves]). We found a reduced amplitude of the P350 and slightly faster reactions for targets with a stress pattern that matched the pitch of the primes (e.g., re_1-REgel) as compared to targets with a stress pattern that did not match the pitch of the primes (e.g., re_1-reGAL). The present study replicates the P350 effect with different material, and indicates that pitch is used for lexical identification in spoken word recognition.

Adult↗

PubMed2004

Gender differences in the activation of inferior frontal cortex during emotional speech perception.

We investigated the brain regions that mediate the processing of emotional speech in men and women by presenting positive and negative words that were spoken with happy or angry prosody. Hence, emotional prosody and word valence were either congruous or incongruous. We assumed that an fRMI contrast between congruous and incongruous presentations would reveal the structures that mediate the interaction of emotional prosody and word valence. The left inferior frontal gyrus (IFG) was more strongly activated in incongruous as compared to congruous trials. This difference in IFG activity was significantly larger in women than in men. Moreover, the congruence effect was significant in women whereas it only appeared as a tendency in men. As the left IFG has been repeatedly implicated in semantic processing, these findings are taken as evidence that semantic processing in women is more susceptible to influences from emotional prosody than is semantic processing in men. Moreover, the present data suggest that the left IFG mediates increased semantic processing demands imposed by an incongruence between emotional prosody and word valence.

Adult↗

PubMed2004

ERPs reflect lexical identification in word fragment priming.

Behavioral evidence suggests that spoken word recognition involves the temporary activation of multiple entries in a listener's mental lexicon. This phenomenon can be demonstrated in cross-modal word fragment priming (CMWP). In CMWP, an auditory word fragment (prime) is immediately followed by a visual word or pseudoword (target). Experiment 1 investigated ERPs for targets presented in this paradigm. Half of the targets were congruent with the prime (e.g., in the prime-target pair: AM-AMBOSS [anvil]), half were not (e.g., AM-PENSUM [pensum]). Lexical entries of the congruent targets should receive activation from the prime. Thus, lexical identification of these targets should be facilitated. An ERP effect named P350, two frontal negative ERP deflections, and the N400 were sensitive to prime-target congruency. In Experiment 2, the relation of the formerly observed ERP effects to processes in a modality-independent mental lexicon was investigated by presenting primes visually. Only the P350 effect could be replicated across different fragment lengths. Therefore, the P350 is discussed as a correlate of lexical identification in a modality-independent mental lexicon.

Adolescent↗

PubMed2003

ERP evidence for a sex-specific Stroop effect in emotional speech.

The present study investigated the interaction of emotional prosody and word valence during emotional comprehension in men and women. In a prosody-word interference task, participants listened to positive, neutral, and negative words that were spoken with a happy, neutral, and angry prosody. Participants were asked to rate word valence while ignoring emotional prosody, or vice versa. Congruent stimuli were responded faster and more accurately as compared to incongruent emotional stimuli. This behavioral effect was more salient for the word valence task than for the prosodic task and was comparable between men and women. The event-related potentials (ERPs) revealed a smaller N400 amplitude for congruent as compared to emotionally incongruent stimuli. This ERP effect, however, was significant only for the word valence judgment and only for female listeners. The present data suggest that the word valence judgment was more difficult and more easily influenced by task-irrelevant emotional information than the prosodic task in both men and women. Furthermore, although emotional prosody and word valence may have a similar influence on an emotional judgment in both sexes, ERPs indicate sex differences in the underlying processing. Women, but not men, show an interaction between prosody and word valence during a semantic processing stage.

Acoustic Stimulation↗

PubMed2003

The brain basis of syntactic processes: functional imaging and lesion studies.

Language comprehension can be subdivided into three processing steps: initial structure building, semantic integration, and late syntactic integration. The two syntactic processing phases are correlated with two distinct components in the event-related brain potential, namely an early left anterior negativity (ELAN) and a late centroparietal positivity (P600). Moreover, ERP findings from healthy adults suggest that early structure-building processes as reflected by the ELAN are independent of semantic processes. fMRI results have revealed that semantic and syntactic processes are supported by separable temporofrontal networks, with the syntactic processes involving the left superior temporal gyrus (STG), the left frontal operculum, and the basal ganglia (BG) in particular. MEG data from healthy adults have indicated that the left anterior temporal region and the left inferior frontal region subserve the early structure building processes. ERP data from patients with lesions in the left anterior temporal region and from patients with lesions in the left inferior frontal gyrus support this view, as these patients do not demonstrate an ELAN, although they do demonstrate a P600. Further results from patients with BG dysfunction suggest that parts of this subcortical structure are involved in late syntactic integrational processes. The data from the different experiments lead to the notion of separable brain systems responsible for early and late syntactic processes, with the former being subserved by the inferior frontal gyrus and the anterior STG and the latter being supported by the BG and more posterior portions of the STG.

Adult↗

PubMed2003

On the lateralization of emotional prosody: an event-related functional MR investigation.

In order to investigate the lateralization of emotional speech we recorded the brain responses to three emotional intonations in two conditions, i.e., "normal" speech and "prosodic" speech (i.e., speech with no linguistic meaning, but retaining the 'slow prosodic modulations' of speech). Participants listened to semantically neutral sentences spoken with a positive, neutral, or negative intonation in both conditions and judged how positive, negative, or neutral the intonation was on a five-point scale. Core peri-sylvian language areas, as well as some frontal and subcortical areas were activated bilaterally in the normal speech condition. In contrast, a bilateral fronto-opercular region was active when participants listened to prosodic speech. Positive and negative intonations elicited a bilateral fronto-temporal and subcortical pattern in the normal speech condition, and more frontal activation in the prosodic speech condition. The current results call into question an exclusive right hemisphere lateralization of emotional prosody and expand patient data on the functional role of the basal ganglia during the perception of emotional prosody.

Adult↗

PubMed2003

Why the P600 is not just a P300: the role of the basal ganglia.

One of the important issues in event-related brain potential research is whether the language-related P600 and the P300 oddball effect are distinct components or not. We addressed this question by testing 14 aphasic patients, half of them with lesions including the basal ganglia and half of them with temporo-parietal lesions, in both an auditory oddball task and an experiment with auditory presented verb inflection violations. Whereas both patient groups displayed a clear P300 effect in the oddball experiment, only the group with temporo-parietal lesions showed a P600 in the language experiment. These data indicate that the basal ganglia seem to play a crucial role in the modulation of the P600, but not of the P300 component.

Aphasia↗

PubMed2003

Syntactic language processing: ERP lesion data on the role of the basal ganglia.

The role of the basal ganglia in syntactic language processing was investigated with event-related brain potentials in fourteen neurologically impaired patients. Seven of these patients had basal ganglia lesions while 7 other patients primarily had lesions of the left temporo-parietal region excluding the basal ganglia. All patients listened to sentences that were either correct or included a verb argument structure violation. In previous experiments this type of violation elicited a biphasic pattern of an N400-P600 complex in young healthy participants. While the N400 may result from incorrect semantic-thematic role assignment, the P600 reflects the fact that verb information does not license the syntactic structure at present. Results of the patient experiment revealed a double dissociation: patients with left temporo-parietal lesions only show a P600, whereas patients with lesions of the basal ganglia showed no P600, but a negativity with extended duration that resembled an N400. The latter pattern not only confirms previous reports that the basal ganglia modulate the P600 but extends these results by showing that the N400 as a late semantic-thematic integration process appears partially modulated by the basal ganglia.

Adult↗

PubMed2003

Syntactic comprehension in Parkinson's disease: investigating early automatic and late integrational processes using event-related brain potentials.

Parkinson's disease (PD) has been associated with a general impairment of procedures and with an impairment of syntactic procedures in particular. The present study investigated comprehension processes in PD using event-related brain potentials (ERPs). PD patients and controls listened to sentences that were either correct or syntactically or semantically incorrect. The language-related ERP component correlated with semantic processes (N400) was present in both groups. In the syntactic domain, early automatic processes (early negativity) appeared normal in PD, whereas late integrational processes (P600) were modulated by this disease. The present findings suggest that the basal ganglia primarily do not support early automatic syntactic processes during comprehension but rather support processes of syntactic integration.

Aged↗