scholarly journals Cortico-Cortical Interactions in Spatial Attention: A Combined ERP/TMS Study

2006 ◽  
Vol 95 (5) ◽  
pp. 3277-3280 ◽  
Author(s):  
Giorgio Fuggetta ◽  
Enea F. Pavone ◽  
Vincent Walsh ◽  
Monika Kiss ◽  
Martin Eimer

To gain insight into the neural basis of visual attention, we combined transcranial magnetic stimulation (TMS) and event-related potentials (ERPs) during a visual search task. Single-pulse TMS over right posterior parietal cortex (rPPC) delayed response times to targets during conjunction search, and this behavioral effect had a direct ERP correlate. The early phase of the N2pc component that reflects the focusing of attention onto target locations in a search display was eliminated over the right hemisphere when TMS was applied there but was present when TMS was delivered to a control site (vertex). This finding demonstrates that rPPC TMS interferes with attentional selectivity in remote visual areas.

2018 ◽  
Author(s):  
Tamar I. Regev ◽  
Jonathan Winawer ◽  
Edden M. Gerber ◽  
Robert T. Knight ◽  
Leon Y. Deouell

AbstractMuch of what is known about the timing of visual processing in the brain is inferred from intracranial studies in monkeys, with human data limited to mainly non-invasive methods with lower spatial resolution. Here, we estimated visual onset latencies from electrocorticographic (ECoG) recordings in a patient who was implanted with 112 sub-dural electrodes, distributed across the posterior cortex of the right hemisphere, for pre-surgical evaluation of intractable epilepsy. Functional MRI prior to surgery was used to determine boundaries of visual areas. The patient was presented with images of objects from several categories. Event Related Potentials (ERPs) were calculated across all categories excluding targets, and statistically reliable onset latencies were determined using a bootstrapping procedure over the single trial baseline activity in individual electrodes. The distribution of onset latencies broadly reflected the known hierarchy of visual areas, with the earliest cortical responses in primary visual cortex, and higher areas showing later responses. A clear exception to this pattern was robust, statistically reliable and spatially localized, very early responses on the bank of the posterior intra-parietal sulcus (IPS). The response in the IPS started nearly simultaneously with responses detected in peristriate visual areas, around 60 milliseconds post-stimulus onset. Our results support the notion of early visual processing in the posterior parietal lobe, not respecting traditional hierarchies, and give direct evidence for the upper limit of onset times of visual responses across the human cortex.


Entropy ◽  
2021 ◽  
Vol 23 (3) ◽  
pp. 304
Author(s):  
Kelsey Cnudde ◽  
Sophia van Hees ◽  
Sage Brown ◽  
Gwen van der Wijk ◽  
Penny M. Pexman ◽  
...  

Visual word recognition is a relatively effortless process, but recent research suggests the system involved is malleable, with evidence of increases in behavioural efficiency after prolonged lexical decision task (LDT) performance. However, the extent of neural changes has yet to be characterized in this context. The neural changes that occur could be related to a shift from initially effortful performance that is supported by control-related processing, to efficient task performance that is supported by domain-specific processing. To investigate this, we replicated the British Lexicon Project, and had participants complete 16 h of LDT over several days. We recorded electroencephalography (EEG) at three intervals to track neural change during LDT performance and assessed event-related potentials and brain signal complexity. We found that response times decreased during LDT performance, and there was evidence of neural change through N170, P200, N400, and late positive component (LPC) amplitudes across the EEG sessions, which suggested a shift from control-related to domain-specific processing. We also found widespread complexity decreases alongside localized increases, suggesting that processing became more efficient with specific increases in processing flexibility. Together, these findings suggest that neural processing becomes more efficient and optimized to support prolonged LDT performance.


2002 ◽  
Vol 13 (01) ◽  
pp. 001-013 ◽  
Author(s):  
James Jerger ◽  
Rebecca Estes

We studied auditory evoked responses to the apparent movement of a burst of noise in the horizontal plane. Event-related potentials (ERPs) were measured in three groups of participants: children in the age range from 9 to 12 years, young adults in the age range from 18 to 34 years, and seniors in the age range from 65 to 80 years. The topographic distribution of grand-averaged ERP activity was substantially greater over the right hemisphere in children and seniors but slightly greater over the left hemisphere in young adults. This finding may be related to age-related differences in the extent to which judgments of sound movement are based on displacement versus velocity information.


2016 ◽  
Vol 48 (2) ◽  
pp. 103-110 ◽  
Author(s):  
Song Xue ◽  
Shanshan Wang ◽  
Xia Kong ◽  
Jiang Qiu

Emotional conflict has received increased attention as a research topic. The objective of this study is to confirm that the processing of emotional conflict is impaired in treatment-resistant depression (TRD). We compared the event-related potentials of 17 patients with TRD and 17 healthy controls during the face-word Stroop task, which is an effective way of assessing the effects of emotional conflict directly. Compared with healthy controls, the accuracy scores of the TRD patients were lower in both “congruent stimuli” and “incongruent stimuli” conditions, and their response times were longer. The TRD patients also had larger N2 amplitudes over the frontal region, regardless of stimulus condition, which might reflect that TRD patients pay more attention to emotional information. A larger P3 amplitude over the frontal region for “incongruent stimuli minus congruent stimuli” was also found among patients with TRD, which indicates interference effects in the Stroop task. The results of this study provide novel behavioral and neurophysiological evidence of anomalies in cognitive inhibition among patients with TRD using the word-face task. These findings not only improve our understanding of deficient inhibition in TRD, but also pave the way for a cognitive neuropsychiatric model of depression.


2003 ◽  
Vol 15 (8) ◽  
pp. 1135-1148 ◽  
Author(s):  
Annett Schirmer ◽  
Sonja A. Kotz

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.


2020 ◽  
Author(s):  
Chenglong Cao ◽  
Jian Song ◽  
Binbin Liu ◽  
Jianren Yue ◽  
Yuzhao Lu ◽  
...  

Abstract Background: Cognitive impairments have been reported in patients with pituitary adenoma; however, there is a lack of knowledge of investigating the emotional stimuli processing in pituitary patients. Thus, we aimed to investigate whether there is emotional processing dysfunction in pituitary patients by recording and analyzing the late positive potential (LPP) elicited by affective stimuli.Methods: Evaluation of emotional stimuli processing by LPP Event related potentials (ERPs) was carried out through central- parietal electrode sites (C3, Cz, C4, P3, Pz, P4) on the head of the patients and healthy controls (HCs).Results: In the negative stimuli, the amplitude of LPP was 2.435 ± 0.419μV for HCs and 0.656 ± 0.427μV for patient group respectively ( p = 0.005). In the positive stimuli, the elicited electric potential 1.450 ± 0.316μV for HCs and 0.495 ± 0.322μV for patient group respectively ( p = 0.040). Moreover, the most obvious difference of LPP amplitude between the two groups existed in the right parietal region. On the right hemisphere (at the P4 site), the elicited electric potential was 1.993 ± 0.299μV for HCs and 0.269 ± 0.305μV for patient group respectively( p = 0.001).Conclusion: There are functional dysfunction of emotional stimuli processing in pituitary adenoma patients. Our research provides the electrophysiological evidence for the presence of cognitive dysfunction which need to be intervened in the pituitary adenoma patients.


2003 ◽  
Vol 15 (7) ◽  
pp. 1039-1051 ◽  
Author(s):  
Ute Leonards ◽  
Julie Palix ◽  
Christoph Michel ◽  
Vicente Ibanez

Functional magnetic resonance imaging studies have indicated that efficient feature search (FS) and inefficient conjunction search (CS) activate partially distinct frontoparietal cortical networks. However, it remains a matter of debate whether the differences in these networks reflect differences in the early processing during FS and CS. In addition, the relationship between the differences in the networks and spatial shifts of attention also remains unknown. We examined these issues by applying a spatio-temporal analysis method to high-resolution visual event-related potentials (ERPs) and investigated how spatio-temporal activation patterns differ for FS and CS tasks. Within the first 450 msec after stimulus onset, scalp potential distributions (ERP maps) revealed 7 different electric field configurations for each search task. Configuration changes occurred simultaneously in the two tasks, suggesting that contributing processes were not significantly delayed in one task compared to the other. Despite this high spatial and temporal correlation, two ERP maps (120–190 and 250–300 msec) differed between the FS and CS. Lateralized distributions were observed only in the ERP map at 250–300 msec for the FS. This distribution corresponds to that previously described as the N2pc component (a negativity in the time range of the N2 complex over posterior electrodes of the hemisphere contralateral to the target hemifield), which has been associated with the focusing of attention onto potential target items in the search display. Thus, our results indicate that the cortical networks involved in feature and conjunction searching partially differ as early as 120 msec after stimulus onset and that the differences between the networks employed during the early stages of FS and CS are not necessarily caused by spatial attention shifts.


1994 ◽  
Vol 6 (3) ◽  
pp. 204-219 ◽  
Author(s):  
Peter Praamstra ◽  
Antje S. Meyer ◽  
Willem J. M. Levelt

Two experiments examined phonological priming effects on reaction times, error rates, and event-related brain potential (ERP) measures in an auditory lexical decision task. In Experiment 1 related prime-target pairs rhymed, and in Experiment 2 they alliterated (i.e., shared the consonantal onset and vowel). Event-related potentials were recorded in a delayed response task. Reaction times and error rates were obtained both for the delayed and an immediate response task. The behavioral data of Experiment 1 provided evidence for phonological facilitation of word, but not of nonword decisions. The brain potentials were more negative to unrelated than to rhyming word-word pairs between 450 and 700 rnsec after target onset. This negative enhancement was not present for word-nonword pairs. Thus, the ERP results match the behavioral data. The behavioral data of Experiment 2 provided no evidence for phonological Facilitation. However, between 250 and 450 msec after target onset, i.e., considerably earlier than in Experiment 1, brain potentials were more negative for unrelated than for alliterating Word-word and word-nonword pairs. It is argued that the ERP effects in the two experiments could be modulations of the same underlying component, possibly the N400. The difference in the timing of the effects is likely to be due to the fact that the shared segments in related stimulus pairs appeared in different word positions in the two experiments.


2001 ◽  
Vol 4 (2) ◽  
pp. 155-168 ◽  
Author(s):  
Ellen R. A. de Bruijn ◽  
Ton Dijkstra ◽  
Dorothee J. Chwilla ◽  
Herbert J. Schriefers

Dutch–English bilinguals performed a generalized lexical decision task on triplets of items, responding with “yes” if all three items were correct Dutch and/or English words, and with “no” if one or more of the items was not a word in either language. Sometimes the second item in a triplet was an interlingual homograph whose English meaning was semantically related to the third item of the triplet (e.g., HOUSE – ANGEL – HEAVEN, where ANGEL means “sting” in Dutch). In such cases, the first item was either an exclusively English (HOUSE) or an exclusively Dutch (ZAAK) word. Semantic priming effects were found in on-line response times. Event-related potentials that were recorded simultaneously showed N400 priming effects thought to reflect semantic integration processes. The response time and N400 priming effects were not affected by the language of the first item in the triplets, providing evidence in support of a strong bottom-up role with respect to bilingual word recognition. The results are interpreted in terms of the Bilingual Interactive Activation model, a language nonselective access model assuming bottom-up priority.


Perception ◽  
10.1068/p5088 ◽  
2003 ◽  
Vol 32 (11) ◽  
pp. 1328-1338 ◽  
Author(s):  
Agnes P Funk ◽  
John D Pettigrew

Motion-induced blindness (MIB) is a phenomenon, perhaps related to perceptual rivalry, where stationary targets disappear and reappear in a cyclic mode when viewed against a background (mask) of coherent, apparent 3-D motion. Since MIB has recently been shown to share similar temporal properties with binocular rivalry, we probed the appearance–disappearance cycle of MIB using unilateral, single-pulse transcranial magnetic stimulation (TMS)—a manipulation that has previously been shown to influence binocular rivalry. Effects were seen for both hemispheres when the timing of TMS was determined prospectively on the basis of a given subject's appearance–disappearance cycle, so that it occurred on average around 300 ms before the time of perceptual switch. Magnetic stimulation of either hemisphere shortened the time to switch from appearance to disappearance and vice versa. However, TMS of left posterior parietal cortex more selectively shortened the disappearance time of the targets if delivered in phase with the disappearance cycle, but lengthened it if TMS was delivered in the appearance phase after the perceptual switch. Opposite effects were seen in the right hemisphere, although less marked than the left-hemisphere effects. As well as sharing temporal characteristics with binocular rivalry, MIB therefore seems to share a similar underlying mechanism of interhemispheric modulation. Interhemispheric switching may thus provide a common temporal framework for uniting the diverse, multilevel phenomena of perceptual rivalry.


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