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.

Effects of unilateral frontal eye-field lesions on eye-head coordination in monkey

1986 ◽  
Vol 55 (4) ◽  
pp. 696-714 ◽  
Author(s):  
J. van der Steen ◽  
I. S. Russell ◽  
G. O. James
Keyword(s):  
Visual Search ◽  
Search Task ◽  
Visual Search Task ◽  
Peak Velocity ◽  
Head Movements ◽  
Frontal Eye Field ◽  
Behavioral Task ◽  
Direct Gaze ◽  
Relative Neglect ◽  
Eye Field

We studied the effects of unilateral frontal eye-field (FEF) lesions on eye-head coordination in monkeys that were trained to perform a visual search task. Eye and head movements were recorded with the scleral search coil technique using phase angle detection in a homogeneous electromagnetic field. In the visual search task all three animals showed a neglect for stimuli presented in the field contralateral to the lesion. In two animals the neglect disappeared within 2-3 wk. One animal had a lasting deficit. We found that FEF lesions that are restricted to area 8 cause only temporary deficits in eye and head movements. Up to a week after the lesion the animals had a strong preference to direct gaze and head to the side ipsilateral to the lesion. Animals tracked objects in contralateral space with combined eye and head movements, but failed to do this with the eyes alone. It was found that within a few days after the lesion, eye and head movements in the direction of the target were initiated, but they were inadequate and had long latencies. Within 1 wk latencies had regained preoperative values. Parallel with the recovery on the behavioral task, head movements became more prominent than before the lesion. Four weeks after the lesion, peak velocity of the head movement had increased by a factor of two, whereas the duration showed a twofold decrease compared with head movements before the lesion. No effects were seen on the duration and peak velocity of gaze. After the recovery on the behavioral task had stabilized, a relative neglect in the hemifield contralateral to the lesion could still be demonstrated by simultaneously presenting two stimuli in the left and right visual hemifields. The neglect is not due to a sensory deficit, but to a disorder of programming. The recovery from unilateral neglect after a FEF lesion is the result of a different orienting behavior, in which head movements become more important. It is concluded that the FEF plays an important role in the organization and coordination of eye and head movements and that lesions of this area result in subtle but permanent changes in eye-head coordination.

Intermodal Compensatory Effects in a Visual Search Task with Congenitally Deaf Adults

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 147-147
Author(s):  
P Stivalet ◽  
Y Moreno ◽  
C Cian ◽  
J Richard ◽  
P-A Barraud
Keyword(s):  
New York ◽  
Visual Search ◽  
Search Task ◽  
Visual Search Task ◽  
Event Related Potentials ◽  
Normal Subjects ◽  
Stimulus Onset ◽  
Search Pattern ◽  
York Academy ◽  
Related Potentials

In a visual search paradigm we measured the stimulus onset asynchrony (SOA) between a stimulus and a mask that was required to reach 90% correct responses. This procedure has the advantage of taking into account the real processing time and excluding the time for the generation of the motor response. Twelve congenitally deaf adult subjects and twelve normal subjects were given a visual search task for a target letter O among a varying number of distractor letters Q and vice-versa. In both groups we found the asymmetrical visual search pattern classically observed with parallel processing for the search for the target Q and with serial processing for the search for the target O (Treisman, 1985 Computer Vision, Graphics, and Image Processing31 156 – 177). The difference between the mean search slopes for an O target was not statistically significant between the groups; this might be due to the variability within the groups. The visual search amidst the congenitally deaf does not seem to benefit from a compensatory effect in relation to the acoustic deprivation. Our results seem to confirm data reported by Neville (1990 Annals of the New York Academy of Science 71 – 91) obtained by an electrophysiological technique based on event-related potentials. Nevertheless, the deaf subjects were 2.5 times faster at the visual search task.

scholarly journals Neural Correlates of Changes in a Visual Search Task due to Cognitive Training in Seniors

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Nele Wild-Wall ◽  
Michael Falkenstein ◽  
Patrick D. Gajewski
Keyword(s):  
Visual Search ◽  
Cognitive Training ◽  
Search Task ◽  
Visual Search Task ◽  
Event Related Potentials ◽  
Training Group ◽  
Cognitive Intervention ◽  
Repetition Effects ◽  
Feature Processing ◽  
Related Potentials

This study aimed to elucidate the underlying neural sources of near transfer after a multidomain cognitive training in older participants in a visual search task. Participants were randomly assigned to a social control, a no-contact control and a training group, receiving a 4-month paper-pencil and PC-based trainer guided cognitive intervention. All participants were tested in a before and after session with a conjunction visual search task. Performance and event-related potentials (ERPs) suggest that the cognitive training improved feature processing of the stimuli which was expressed in an increased rate of target detection compared to the control groups. This was paralleled by enhanced amplitudes of the frontal P2 in the ERP and by higher activation in lingual and parahippocampal brain areas which are discussed to support visual feature processing. Enhanced N1 and N2 potentials in the ERP for nontarget stimuli after cognitive training additionally suggest improved attention and subsequent processing of arrays which were not immediately recognized as targets. Possible test repetition effects were confined to processes of stimulus categorisation as suggested by the P3b potential. The results show neurocognitive plasticity in aging after a broad cognitive training and allow pinpointing the functional loci of effects induced by cognitive training.

scholarly journals Sequential Operations Revealed by Serendipitous Feature Selectivity in Frontal Eye Field

2019 ◽  
Author(s):  
Kaleb A. Lowe ◽  
Jeffrey D. Schall
Keyword(s):  
Visual Search ◽  
Search Task ◽  
Visual Search Task ◽  
Target Selection ◽  
Stimulus Orientation ◽  
Saccade Target ◽  
Frontal Eye Field ◽  
Eye Field ◽  
Feature Selectivity ◽  
Selection Indexes

ABSTRACTNeurons in macaque frontal eye field contribute to spatial but typically not feature selection during visual search. Using an innovative visual search task, we report a serendipitous discovery that some frontal eye field neurons can develop rapid selectivity for stimulus orientation that is used to guide gaze during a visual search task with pro-saccade and anti-saccade responses. This feature selectivity occurs simultaneously at multiple locations for all objects sharing that feature and coincides with when neurons select the singleton of a search array. This feature selectivity also reveals the distinct, subsequent operation of selecting the endpoint of the saccade in pro-saccade as well as anti-saccade trials. These results demonstrate that target selection preceding saccade preparation is composed of multiple operations. We conjecture that singleton selection indexes the allocation of attention, which can be divided, to conspicuous items. Consequently, endpoint selection indexes the focused allocation of attention to the endpoint of the saccade. These results demonstrate that saccade target selection is not a unitary process.SIGNIFICANCE STATEMENTFrontal eye field is well known to contribute to spatial selection for attention and eye movements. We discovered that some frontal eye field neurons can acquire selectivity for stimulus orientation when it guides visual search. The chronometry of neurons with and without feature selectivity reveal distinct operations accomplishing visual search.

scholarly journals Looking for a face in the crowd: Fixation-related potentials in an eye-movement visual search task

NeuroImage ◽  
2014 ◽  
Vol 89 ◽  
pp. 297-305 ◽  
Author(s):  
Lisandro N. Kaunitz ◽  
Juan E. Kamienkowski ◽  
Alexander Varatharajah ◽  
Mariano Sigman ◽  
Rodrigo Quian Quiroga ◽  
...  
Keyword(s):  
Visual Search ◽  
Eye Movement ◽  
Search Task ◽  
Visual Search Task ◽  
Related Potentials

scholarly journals Difficulty of Visual Search Modulates Neuronal Interactions and Response Variability in the Frontal Eye Field

2007 ◽  
Vol 98 (5) ◽  
pp. 2580-2587 ◽  
Author(s):  
Jeremiah Y. Cohen ◽  
Pierre Pouget ◽  
Geoffrey F. Woodman ◽  
Chenchal R. Subraveti ◽  
Jeffrey D. Schall ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Visual Search ◽  
Search Task ◽  
Response Variability ◽  
Frontal Eye Field ◽  
Search Tasks ◽  
Saccade Onset ◽  
Neuronal Interactions ◽  
Eye Field ◽  
Spiking Activity

The frontal eye field (FEF) is involved in selecting visual targets for eye movements. To understand how populations of FEF neurons interact during target selection, we recorded activity from multiple neurons simultaneously while macaques performed two versions of a visual search task. We used a multivariate analysis in a point process statistical framework to estimate the instantaneous firing rate and compare interactions among neurons between tasks. We found that FEF neurons were engaged in more interactions during easier visual search tasks compared with harder search tasks. In particular, eye movement–related neurons were involved in more interactions than visual-related neurons. In addition, our analysis revealed a decrease in the variability of spiking activity in the FEF beginning ∼100 ms before saccade onset. The minimum in response variability occurred ∼20 ms earlier for the easier search task compared with the harder one. This difference is positively correlated with the difference in saccade reaction times for the two tasks. These findings show that a multivariate analysis can provide a measure of neuronal interactions and characterize the spiking activity of FEF neurons in the context of a population of neurons.

scholarly journals Distinguishing between target and nontarget fixations in a visual search task using fixation-related potentials

2013 ◽  
Vol 13 (3) ◽  
pp. 17-17 ◽  
Author(s):  
A.-M. Brouwer ◽  
B. Reuderink ◽  
J. Vincent ◽  
M. A. J. van Gerven ◽  
J. B. F. van Erp
Keyword(s):  
Visual Search ◽  
Search Task ◽  
Visual Search Task ◽  
Related Potentials

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.

Sign in / Sign up

Export Citation Format

Share Document