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.

scholarly journals Neural Basis of the Set-Size Effect in Frontal Eye Field: Timing of Attention During Visual Search

2009 ◽  
Vol 101 (4) ◽  
pp. 1699-1704 ◽  
Author(s):  
Jeremiah Y. Cohen ◽  
Richard P. Heitz ◽  
Geoffrey F. Woodman ◽  
Jeffrey D. Schall
Keyword(s):  
Visual Search ◽  
Response Time ◽  
Visual Target ◽  
Target Selection ◽  
Target Object ◽  
Frontal Eye Field ◽  
Neural Basis ◽  
Set Size ◽  
Eye Field ◽  
Recorded Activity

Visual search for a target object among distractors often takes longer when more distractors are present. To understand the neural basis of this capacity limitation, we recorded activity from visually responsive neurons in the frontal eye field (FEF) of macaque monkeys searching for a target among distractors defined by form (randomly oriented T or L). To test the hypothesis that the delay of response time with increasing number of distractors originates in the delay of attention allocation by FEF neurons, we manipulated the number of distractors presented with the search target. When monkeys were presented with more distractors, visual target selection was delayed and neuronal activity was reduced in proportion to longer response time. These findings indicate that the time taken by FEF neurons to select the target contributes to the variation in visual search efficiency.

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.

scholarly journals Strategic and non-strategic semantic expectations hierarchically modulate neural processing

2020 ◽  
Author(s):  
Consuelo Vidal-Gran ◽  
Rodika Sokoliuk ◽  
Howard Bowman ◽  
Damian Cruse
Keyword(s):  
Auditory Processing ◽  
Prediction Error ◽  
Event Related Potentials ◽  
Unrelated Word ◽  
Task Demands ◽  
Prediction Errors ◽  
Neural Basis ◽  
Global Context ◽  
Priming Paradigm ◽  
Related Potentials

AbstractPerception is facilitated by a hierarchy of expectations generated from context and prior knowledge. In auditory processing, violations of local (within-trial) expectations elicit a mismatch negativity, while violations of global (across-trial) expectations elicit a later positive component (P300). This result is taken as evidence of prediction errors ascending through the expectation hierarchy. However, in language comprehension, there is no evidence that violations of semantic expectations across local-global levels similarly elicit a sequence of hierarchical error signals – thus drawing into question the putative link between event-related potentials and prediction errors. We investigated the neural basis of such hierarchical expectations of semantics in a word-pair priming paradigm. By manipulating the overall proportion of related or unrelated word-pairs across the task, we created two global contexts that differentially encouraged strategic use of primes. Across two experiments, we replicated behavioural evidence of greater priming in the high validity context, reflecting strategic expectations of upcoming targets based on ‘global’ context. In our pre-registered EEG analyses, we observed a ‘local’ prediction error ERP effect (i.e. semantic priming) approximately 250ms post-target, which, in exploratory analyses, was followed 100ms later by a signal that interacted with the global context. However, the later effect behaved in an apredictive manner - i.e. was most extreme for fulfilled expectations, rather than violations. Our results are consistent with interpretations of early ERPs as reflections of prediction error and later ERPs as processes related to conscious access and in support of task demands.Significance statementSemantic expectations have been associated with the ERP N400 component, which is modulated by semantic prediction errors across levels of the hierarchy. However, there is no evidence of a two-stage profile that reflects violations of semantic expectations at a single level of the hierarchy, such as the MMN and P3b observed in the local-global paradigm, which are elicited by violations of local and global expectations, respectively. In the present study, we provided evidence of an early ERP effect that reflects violations of local semantic expectations, followed by an apredictive signal that interacted with the global context. Thus, these results support the notion of early ERPs as prediction errors and later ERPs reflecting conscious access and strategic use of context.

scholarly journals Rapid Parallel Attentional Selection Can Be Controlled by Shape and Alphanumerical Category

2016 ◽  
Vol 28 (11) ◽  
pp. 1672-1687 ◽  
Author(s):  
Michael Jenkins ◽  
Anna Grubert ◽  
Martin Eimer
Keyword(s):  
Attentional Control ◽  
Time Course ◽  
Target Selection ◽  
Attentional Selection ◽  
Visual Features ◽  
Multiple Target ◽  
Neural Basis ◽  
Selection Processes ◽  
Selection Tasks ◽  
Selection Of

Previous research has shown that when two color-defined target objects appear in rapid succession at different locations, attention is deployed independently and in parallel to both targets. This study investigated whether this rapid simultaneous attentional target selection mechanism can also be employed in tasks where targets are defined by a different visual feature (shape) or when alphanumerical category is the target selection attribute. Two displays that both contained a target and a nontarget object on opposite sides were presented successively, and the SOA between the two displays was 100, 50, 20, or 10 msec in different blocks. N2pc components were recorded to both targets as a temporal marker of their attentional selection. When observers searched for shape-defined targets (Experiment 1), N2pc components to the two targets were equal in size and overlapped in time when the SOA between the two displays was short, reflecting two parallel shape-guided target selection processes with their own independent time course. Essentially the same temporal pattern of N2pc components was observed when alphanumerical category was the target-defining attribute (Experiment 2), demonstrating that the rapid parallel attentional selection of multiple target objects is not restricted to situations where the deployment of attention can be guided by elementary visual features but that these processes can even be employed in category-based attentional selection tasks. These findings have important implications for our understanding of the cognitive and neural basis of top–down attentional control.

Neural basis of saccade target selection in frontal eye field during visual search

Nature ◽  
1993 ◽  
Vol 366 (6454) ◽  
pp. 467-469 ◽  
Author(s):  
Jeffrey D. Schall ◽  
Doug P. Hanes
Keyword(s):  
Visual Search ◽  
Target Selection ◽  
Saccade Target ◽  
Frontal Eye Field ◽  
Neural Basis ◽  
Eye Field

scholarly journals The neural basis of authenticity recognition in laughter and crying

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maciej Kosilo ◽  
Mónica Costa ◽  
Helen E. Nuttall ◽  
Hugo Ferreira ◽  
Sophie Scott ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Time Course ◽  
Event Related Potentials ◽  
Higher Order ◽  
Emotional Content ◽  
Emotional Expressions ◽  
Neural Basis ◽  
Related Potentials ◽  
Motivational Salience ◽  
The Impact

AbstractDeciding whether others’ emotions are genuine is essential for successful communication and social relationships. While previous fMRI studies suggested that differentiation between authentic and acted emotional expressions involves higher-order brain areas, the time course of authenticity discrimination is still unknown. To address this gap, we tested the impact of authenticity discrimination on event-related potentials (ERPs) related to emotion, motivational salience, and higher-order cognitive processing (N100, P200 and late positive complex, the LPC), using vocalised non-verbal expressions of sadness (crying) and happiness (laughter) in a 32-participant, within-subject study. Using a repeated measures 2-factor (authenticity, emotion) ANOVA, we show that N100’s amplitude was larger in response to authentic than acted vocalisations, particularly in cries, while P200’s was larger in response to acted vocalisations, particularly in laughs. We suggest these results point to two different mechanisms: (1) a larger N100 in response to authentic vocalisations is consistent with its link to emotional content and arousal (putatively larger amplitude for genuine emotional expressions); (2) a larger P200 in response to acted ones is in line with evidence relating it to motivational salience (putatively larger for ambiguous emotional expressions). Complementarily, a significant main effect of emotion was found on P200 and LPC amplitudes, in that the two were larger for laughs than cries, regardless of authenticity. Overall, we provide the first electroencephalographic examination of authenticity discrimination and propose that authenticity processing of others’ vocalisations is initiated early, along that of their emotional content or category, attesting for its evolutionary relevance for trust and bond formation.

Face and Word Recognition in Patients with Left and Right Hemispheric Lesions: Evidence from Reaction Times and ERPs

2002 ◽  
Vol 13 (1) ◽  
pp. 69-83 ◽  
Author(s):  
Stefan R. Schweinberger ◽  
Thomas Klos ◽  
Werner Sommer
Keyword(s):  
Slow Wave ◽  
Reaction Times ◽  
Memory Search ◽  
Event Related Potentials ◽  
Performance Deficits ◽  
Set Size ◽  
Left Brain ◽  
Related Potentials ◽  
Abstract Words ◽  
Left Brain Damage

Abstract: We recorded reaction times (RTs) and event-related potentials (ERPs) in patients with unilateral lesions during a memory search task. Participants memorized faces or abstract words, which were then recognized among new ones. The RT deficit found in patients with left brain damage (LBD) for words increased with memory set size, suggesting that their problem relates to memory search. In contrast, the RT deficit found in patients with RBD for faces was apparently related to perceptual encoding, a conclusion also supported by their reduced P100 ERP component. A late slow wave (720-1720 ms) was enhanced in patients, particularly to words in patients with LBD, and to faces in patients with RBD. Thus, the slow wave was largest in the conditions with most pronounced performance deficits, suggesting that it reflects deficit-related resource recruitment.

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