scholarly journals Timing of attentional selection in frontal eye field and event-related potentials over visual cortex during pop-out search

2010 ◽  
Vol 10 (7) ◽  
pp. 97-97 ◽  
Author(s):  
B. Purcell ◽  
R. Heitz ◽  
J. Cohen ◽  
G. Woodman ◽  
J. Schall
Keyword(s):  
Visual Cortex ◽  
Event Related Potentials ◽  
Attentional Selection ◽  
Frontal Eye Field ◽  
Related Potentials ◽  
Eye Field

scholarly journals On the origin of event-related potentials indexing covert attentional selection during visual search: timing of selection by macaque frontal eye field and event-related potentials during pop-out search

2013 ◽  
Vol 109 (2) ◽  
pp. 557-569 ◽  
Author(s):  
Braden A. Purcell ◽  
Jeffrey D. Schall ◽  
Geoffrey F. Woodman
Keyword(s):  
Time Course ◽  
Target Selection ◽  
Event Related Potentials ◽  
Attentional Selection ◽  
Task Demands ◽  
Frontal Eye Field ◽  
Neural Basis ◽  
Set Size ◽  
Related Potentials ◽  
Eye Field

Event-related potentials (ERPs) have provided crucial data concerning the time course of psychological processes, but the neural mechanisms producing ERP components remain poorly understood. This study continues a program of research in which we investigated the neural basis of attention-related ERP components by simultaneously recording intracranially and extracranially from macaque monkeys. Here, we compare the timing of attentional selection by the macaque homologue of the human N2pc component (m-N2pc) with the timing of selection in the frontal eye field (FEF), an attentional-control structure believed to influence posterior visual areas thought to generate the N2pc. We recorded FEF single-unit spiking and local field potentials (LFPs) simultaneously with the m-N2pc in monkeys performing an efficient pop-out search task. We assessed how the timing of attentional selection depends on task demands by direct comparison with a previous study of inefficient search in the same monkeys (e.g., finding a T among Ls). Target selection by FEF spikes, LFPs, and the m-N2pc was earlier during efficient pop-out search rather than during inefficient search. The timing and magnitude of selection in all three signals varied with set size during inefficient but not efficient search. During pop-out search, attentional selection was evident in FEF spiking and LFP before the m-N2pc, following the same sequence observed during inefficient search. These observations are consistent with the hypothesis that feedback from FEF modulates neural activity in posterior regions that appear to generate the m-N2pc even when competition for attention among items in a visual scene is minimal.

Neural correlates of changing intention in the human FEF and IPS

2012 ◽  
Vol 107 (3) ◽  
pp. 859-867 ◽  
Author(s):  
Duncan E. Astle ◽  
Elena Nixon ◽  
Stephen R. Jackson ◽  
Georgina M. Jackson
Keyword(s):  
Event Related Potentials ◽  
Neural Correlates ◽  
Smooth Transition ◽  
Frontal Eye Field ◽  
Top Down ◽  
Mental Flexibility ◽  
Related Potentials ◽  
Eye Field ◽  
The Right ◽  
Prior Intention

Previous research demonstrates that our apparent mental flexibility depends largely on the strength of our prior intention; changing our intention in advance enables a smooth transition from one task to another (e.g., Astle DE, Jackson GM, Swainson R. J Cogn Neurosci 20: 255–267, 2008; Duncan J, Emslie H, Williams P, Johnson R, Freer C. Cogn Psychol 30: 257–303, 1996; Husain M, Parton A, Hodgson TL, Mort D, Rees G. Nat Neurosci 6: 117–118, 2003). However, these necessarily rapid anticipatory mechanisms have been difficult to study in the human brain. We used EEG and magnetoencephalography, specifically event-related potentials and fields (ERPs and ERFs), respectively, to explore the neural correlates of this important aspect of mental flexibility. Subjects performed a manual version of a pro/antisaccade task using preparatory cues to switch between the pro- and antirules. When subjects switched their intention, we observed a positivity over central electrodes, which correlated significantly with our behavioral data; the greater the ERP effect, the stronger the subject's change of intention. ERFs, alongside subject-specific structural MRIs, were used to project into source space. When subjects switched their intention, they showed significantly elevated activity in the right frontal eye field and left intraparietal sulcus (IPS); the greater the left IPS activity on switch trials, the stronger the subject's change of intention. This network has previously been implicated in the top-down control of eye movements, but here we demonstrate its role in the top-down control of a task set, in particular, that it is recruited when we change the task that we intend to perform.

scholarly journals On the Origin of Event-Related Potentials Indexing Covert Attentional Selection During Visual Search

2009 ◽  
Vol 102 (4) ◽  
pp. 2375-2386 ◽  
Author(s):  
Jeremiah Y. Cohen ◽  
Richard P. Heitz ◽  
Jeffrey D. Schall ◽  
Geoffrey F. Woodman
Keyword(s):  
Visual Search ◽  
Search Task ◽  
Visual Search Task ◽  
Event Related Potentials ◽  
Frontal Eye Field ◽  
Field Potentials ◽  
Electrophysiological Studies ◽  
Human Experiments ◽  
Related Potentials ◽  
Eye Field

Despite nearly a century of electrophysiological studies recording extracranially from humans and intracranially from monkeys, the neural generators of nearly all human event-related potentials (ERPs) have not been definitively localized. We recorded an attention-related ERP component, known as the N2pc, simultaneously with intracranial spikes and local field potentials (LFPs) in macaques to test the hypothesis that an attentional-control structure, the frontal eye field (FEF), contributed to the generation of the macaque homologue of the N2pc (m-N2pc). While macaques performed a difficult visual search task, the search target was selected earliest by spikes from single FEF neurons, later by FEF LFPs, and latest by the m-N2pc. This neurochronometric comparison provides an empirical bridge connecting macaque and human experiments and a step toward localizing the neural generator of this important attention-related ERP component.

Modulating oscillations in human visual cortex using frontal eye-field TMS

NeuroImage ◽  
2009 ◽  
Vol 47 ◽  
pp. S67
Author(s):  
N Hoogenboom ◽  
J Lauder ◽  
MH Grosbras
Keyword(s):  
Visual Cortex ◽  
Frontal Eye Field ◽  
Human Visual Cortex ◽  
Eye Field

scholarly journals Dopamine Receptor Expression Among Local and Visual Cortex-Projecting Frontal Eye Field Neurons

2019 ◽  
Vol 30 (1) ◽  
pp. 148-164 ◽  
Author(s):  
Adrienne Mueller ◽  
Rebecca M Krock ◽  
Steven Shepard ◽  
Tirin Moore
Keyword(s):  
Visual Cortex ◽  
Pyramidal Neurons ◽  
Receptor Expression ◽  
Inhibitory Neurons ◽  
Extrastriate Cortex ◽  
Frontal Eye Field ◽  
D2 Dopamine Receptors ◽  
Dopaminergic Modulation ◽  
Eye Field ◽  
Parvalbumin Neurons

Abstract Dopaminergic modulation of prefrontal cortex plays an important role in numerous cognitive processes, including attention. The frontal eye field (FEF) is modulated by dopamine and has an established role in visual attention, yet the underlying circuitry upon which dopamine acts is not known. We compared the expression of D1 and D2 dopamine receptors (D1Rs and D2Rs) across different classes of FEF neurons, including those projecting to dorsal or ventral extrastriate cortex. First, we found that both D1Rs and D2Rs are more prevalent on pyramidal neurons than on several classes of interneurons and are particularly prevalent on putatively long-range projecting pyramidals. Second, higher proportions of pyramidal neurons express D1Rs than D2Rs. Third, overall a higher proportion of inhibitory neurons expresses D2Rs than D1Rs. Fourth, among inhibitory interneurons, a significantly higher proportion of parvalbumin+ neurons expresses D2Rs than D1Rs, and a significantly higher proportion of calbindin+ neurons expresses D1Rs than D2Rs. Finally, compared with D2Rs, virtually all of the neurons with identified projections to both dorsal and ventral extrastriate visual cortex expressed D1Rs. Our results demonstrate that dopamine tends to act directly on the output of the FEF and that dopaminergic modulation of top-down projections to visual cortex is achieved predominately via D1Rs.

scholarly journals Psychophysiology and Imaging of Visual Cortical Functions in the Blind: A Review

2008 ◽  
Vol 20 (3-4) ◽  
pp. 71-81 ◽  
Author(s):  
Stephanie L. Simon-Dack ◽  
P. Dennis Rodriguez ◽  
Wolfgang A. Teder-Sälejärvi
Keyword(s):  
Visual Cortex ◽  
Transcranial Magnetic Stimulation ◽  
Visual Information ◽  
Magnetic Stimulation ◽  
Late Onset ◽  
Event Related Potentials ◽  
Cortical Activation ◽  
Future Research ◽  
Related Potentials ◽  
Visual Cortical

Imaging, transcranial magnetic stimulation, and psychophysiological recordings of the congenitally blind have confirmed functional activation of the visual cortex but have not extensively explained the functional significance of these activation patterns in detail. This review systematically examines research on the role of the visual cortex in processing spatial and non-visual information, highlighting research on individuals with early and late onset blindness. Here, we concentrate on the methods utilized in studying visual cortical activation in early blind participants, including positron emissions tomography (PET), functional magnetic resonance imaging (fMRI), transcranial magnetic stimulation (TMS), and electrophysiological data, specifically event-related potentials (ERPs). This paper summarizes and discusses findings of these studies. We hypothesize how mechanisms of cortical plasticity are expressed in congenitally in comparison to adventitiously blind and short-term visually deprived sighted participants and discuss potential approaches for further investigation of these mechanisms in future research.

scholarly journals Pre-Stimulus Alpha-Band Phase Gates Afferent Visual Cortex Responses

2021 ◽  
Author(s):  
Wei Dou ◽  
Audrey Morrow ◽  
Luca Iemi ◽  
Jason Samaha
Keyword(s):  
Visual Cortex ◽  
Visual Processing ◽  
Time Window ◽  
Event Related Potentials ◽  
Alpha Phase ◽  
Alpha Activity ◽  
Alpha Band ◽  
Visual Responses ◽  
Alpha Oscillations ◽  
Related Potentials

The neurogenesis of alpha-band (8-13 Hz) activity has been characterized across many different animal experiments. However, the functional role that alpha oscillations play in perception and behavior has largely been attributed to two contrasting hypotheses, with human evidence in favor of either (or both or neither) remaining sparse. On the one hand, alpha generators have been observed in relay sectors of the visual thalamus and are postulated to phasically inhibit afferent visual input in a feedforward manner 1-4. On the other hand, evidence also suggests that the direction of influence of alpha activity propagates backwards along the visual hierarchy, reflecting a feedback influence upon the visual cortex 5-9. The primary source of human evidence regarding the role of alpha phase in visual processing has been on perceptual reports 10-16, which could be modulated either by feedforward or feedback alpha activity. Thus, although these two hypotheses are not mutually exclusive, human evidence clearly supporting either one is lacking. Here, we present human subjects with large, high-contrast visual stimuli that elicit robust C1 event-related potentials (ERP), which peak between 70-80 milliseconds post-stimulus and are thought to reflect afferent primary visual cortex (V1) input 17-20. We find that the phase of ongoing alpha oscillations modulates the global field power (GFP) of the EEG during this first volley of stimulus processing (the C1 time-window). On the standard assumption 21-23 that this early activity reflects postsynaptic potentials being relayed to visual cortex from the thalamus, our results suggest that alpha phase gates visual responses during the first feed-forward sweep of processing.

Stereotactic electroencephalography in humans reveals multisensory signal in early visual and auditory cortices

2019 ◽  
Author(s):  
Stefania Ferraro ◽  
Markus J. Van Ackeren ◽  
Roberto Mai ◽  
Laura Tassi ◽  
Francesco Cardinale ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Auditory Cortex ◽  
Auditory Processing ◽  
Multisensory Processing ◽  
Low Frequency ◽  
Event Related Potentials ◽  
Stimulus Onset ◽  
Oscillatory Activity ◽  
Visual Responses ◽  
Related Potentials

AbstractUnequivocally demonstrating the presence of multisensory signals at the earliest stages of cortical processing remains challenging in humans. In our study, we relied on the unique spatio-temporal resolution provided by intracranial stereotactic electroencephalographic (SEEG) recordings in patients with drug-resistant epilepsy to characterize the signal extracted from early visual (calcarine and pericalcarine) and auditory (Heschl’s gyrus and planum temporale) regions during a simple audio-visual oddball task. We provide evidences that both cross-modal responses (visual responses in auditory cortex or the reverse) and multisensory processing (alteration of the unimodal responses during bimodal stimulation) can be observed in intracranial event-related potentials (iERPs) and in power modulations of oscillatory activity at different temporal scales within the first 150 ms after stimulus onset. The temporal profiles of the iERPs are compatible with the hypothesis that MSI occurs by means of direct pathways linking early visual and auditory regions. Our data indicate, moreover, that MSI mainly relies on modulations of the low-frequency bands (foremost the theta band in the auditory cortex and the alpha band in the visual cortex), suggesting the involvement of feedback pathways between the two sensory regions. Remarkably, we also observed high-gamma power modulations by sounds in the early visual cortex, thus suggesting the presence of neuronal populations involved in auditory processing in the calcarine and pericalcarine region in humans.

scholarly journals Nasotemporal ERP differences: evidence for increased inhibition of temporal distractors

2015 ◽  
Vol 113 (7) ◽  
pp. 2210-2219 ◽  
Author(s):  
Christoph Huber-Huber ◽  
Anna Grubert ◽  
Ulrich Ansorge ◽  
Martin Eimer
Keyword(s):  
Attentional Bias ◽  
Event Related Potentials ◽  
Attentional Selection ◽  
Top Down ◽  
Distractor Inhibition ◽  
Visual Hemifield ◽  
Target Digit ◽  
Related Potentials ◽  
Attentional Inhibition ◽  
Visual Hemifields

Previous research has demonstrated behavioral advantages for stimuli in the temporal relative to the nasal visual hemifield. To investigate whether this nasotemporal asymmetry reflects a genuinely attentional bias, we recorded event-related potentials in a task where participants identified a color-defined target digit in one visual hemifield that was accompanied by an irrelevant distractor in the opposite hemifield ( experiment 1). To dissociate the processing of stimuli in nasal and temporal visual hemifields, an eye-patching procedure was used. Targets triggered N2pc components that marked their attentional selection. Unexpectedly, these N2pc components were larger and emerged earlier for nasal relative to temporal targets. Experiment 2 provided evidence that this nasotemporal asymmetry for the N2pc is linked to an increased attentional inhibition of temporal distractors. Relative to nasal distractors, temporal distractors elicited an increased inhibition-related contralateral positivity, resulting in more pronounced differences between contralateral and ipsilateral event-related potentials on trials with temporal distractors and nasal targets. These results provide novel evidence for a genuinely attentional contribution to nasotemporal asymmetries and suggest that such asymmetries are associated with top-down controlled distractor inhibition.

scholarly journals Lateralized Frontal Eye Field Activity Precedes Occipital Activity Shortly before Saccades: Evidence for Cortico-cortical Feedback as a Mechanism Underlying Covert Attention Shifts

2010 ◽  
Vol 22 (9) ◽  
pp. 1931-1943 ◽  
Author(s):  
Tjerk P. Gutteling ◽  
Helene M. van Ettinger-Veenstra ◽  
J. Leon Kenemans ◽  
Sebastiaan F. W. Neggers
Keyword(s):  
Visual Cortex ◽  
Discrimination Performance ◽  
Covert Attention ◽  
Saccade Target ◽  
Frontal Eye Field ◽  
Cortical Connections ◽  
Field Activity ◽  
Eye Field ◽  
Frontal Activity ◽  
Saccade Direction

When an eye movement is prepared, attention is shifted toward the saccade end-goal. This coupling of eye movements and spatial attention is thought to be mediated by cortical connections between the FEFs and the visual cortex. Here, we present evidence for the existence of these connections. A visual discrimination task was performed while recording the EEG. Discrimination performance was significantly improved when the discrimination target and the saccade target matched. EEG results show that frontal activity precedes occipital activity contralateral to saccade direction when the saccade is prepared but not yet executed; these effects were absent in fixation conditions. This is consistent with the idea that the FEF exerts a direct modulatory influence on the visual cortex and enhances perception at the saccade end-goal.

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