Event-related potentials in the retina and optic tectum of fish

1990 ◽  
Vol 64 (3) ◽  
pp. 903-914 ◽  
Author(s):  
T. H. Bullock ◽  
M. H. Hofmann ◽  
F. K. Nahm ◽  
J. G. New ◽  
J. C. Prechtl
Keyword(s):  
Optic Nerve ◽  
Visual Evoked Potentials ◽  
Optic Tectum ◽  
Event Related Potentials ◽  
Distal Stump ◽  
Diffuse Light ◽  
Field Potentials ◽  
Related Potentials ◽  
Flicker Fusion ◽  
Light Flashes

1. Compound field potentials were recorded with up to 18 microelectrodes in comb, brush, or spear arrays on and in the optic tectum and with suction electrodes from the distal stump of the cut optic nerve and from the optic nerve head in the opened eye in elasmobranchs and teleosts. Diffuse light flashes of different durations and submaximal intensities were delivered in trains with regular or irregular interstimulus intervals (ISI). 2. Event-related potentials (ERPs) are visible in single trials and begin at 50-200 ms after an "oddball" flash, especially one that is slightly weaker, briefer, or delayed by as little as 6% of ISI, compared with the more frequent stimulus. ERPs to the opposite condition are not of the same form or size. 3. One or more stimuli were omitted from a train or the train terminated after various conditioning times. Deflections occur beyond the expected visual-evoked potentials (VEPs) to the last flash and are called omitted-stimulus potentials (OSPs). They occur on schedule--approximately 100 ms after the next flash would be due--almost independent of intensity, duration, or conditioning time. They are considered to be ERPs without any necessary implication or denial of a temporally specific expectation. 4. Three components of OSP occur alone or in combination: an initial fast peak, a slow wave, and an oscillatory spindle up to ls or more in duration. This resembles the OFF response to steady light. 5. All these components are already present in the retina with optic nerve cut. 6. The same mean ISI with a high proportion of jitter gives OSPs with only slightly longer latencies and smaller amplitudes; the OSP acts as though the retina makes an integrated prediction of ISI, intensity, and duration. 7. During a conditioning train the equilibrium between excitation and inhibition after each flash changes according to frequency, intensity, duration, and conditioning time; the VEP reflects this in a shape unique to the ISI; inhibition increases rapidly after each flash and then decays slowly according to the recent mean ISI. This allows rebound disinhibition after missing, weak, or delayed flashes (OSP or ERP) or causes an altered VEP after a longer or stronger oddball. 8. It seems unlikely that the OSP or oddball ERP in fish tectum is equivalent to mammalian ERPs under the same regime or signals higher cognitive events, because they are already present in the retina, require flash frequencies greater than 1 Hz, and grow with frequency up to and beyond flicker fusion.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Unexpected changes in learned task contingencies trigger sharp wave ripples in the primate hippocampus during virtual navigation

2020 ◽  
Author(s):  
Mary McIntosh ◽  
Benjamin Corrigan ◽  
Roberto Gulli ◽  
Guillaume Doucet ◽  
Julio Martinez-Trujillo ◽  
...  
Keyword(s):  
Associative Learning ◽  
Memory Consolidation ◽  
Event Related Potentials ◽  
Field Potentials ◽  
Virtual Navigation ◽  
Temporal Lobes ◽  
Sharp Wave ◽  
Learning Tasks ◽  
Related Potentials ◽  
3D Virtual Environment

Abstract The hippocampi and mesial temporal lobes play a central role in episodic memory and associative learning. It is unclear how unexpected experience influences learning. Hippocampal sharp wave ripples (SWR) are an electrical biomarker of memory consolidation. We tracked when and where SWR occur during 2 tasks. Local field potentials were recorded in the hippocampi, entorhinal cortices and amygdalae of non-human primates (NHP; n=3) performing reversal and associative learning tasks in a 3D virtual environment. Our results show hippocampal SWR occurred when learned task contingencies were unexpectedly altered. Surprise rewards and reward denial were associated with SWR rates 9.8x and 8.0x greater than expected rewards. The highest density of SWR occurred in zones where errors were made. SWR were preceded by event-related potentials in the amygdala but not entorhinal cortex. Our results suggest that SWR generation in primates may prioritize behaviourally relevant experience for commitment to memory to allow flexible learning.

scholarly journals Multimodal evoked potential abnormalities in patients with Wilson's disease

2005 ◽  
Vol 133 (7-8) ◽  
pp. 331-337 ◽  
Author(s):  
Tihomir Ilic ◽  
Marina Svetel ◽  
Stevan Petkovic ◽  
Vladimir Kostic
Keyword(s):  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Somatosensory Evoked Potentials ◽  
Evoked Potential ◽  
Wilson’S Disease ◽  
Event Related Potentials ◽  
Wilson's Disease ◽  
Illness Duration ◽  
Functional Systems ◽  
Related Potentials

The aim of this study was to investigate the involvement of the following functional systems: somatosensory evoked potentials (SSEP), visual evoked potentials (VEP), and event related potentials (ERP), in twenty patients with Wilson's disease (WD). VEP and SSEP abnormalities were discovered in S patients respectively (40%), whereas ERP were either absent or, in the case of 10 patients (50%), had significantly prolonged P-300 latencies. Taken together, at least one evoked potential abnormality was discovered in 17 patients (85%]. Only in 3 patients (15%), involving either the isolated hepatic type of disease or short illness duration of the neurological type, were normal evoked potential findings observed. Our findings suggest the usefulness of multimodal evoked potential abnormalities in the evaluation of subclinical manifestations in patients with WD.

Visual evoked potentials and long latency event-related potentials in chronic renal failure

Neurology ◽  
1983 ◽  
Vol 33 (9) ◽  
pp. 1219-1219 ◽  
Author(s):  
S. N. Cohen ◽  
K. Syndulko ◽  
B. Rever ◽  
J. Kraut ◽  
J. Coburn ◽  
...  
Keyword(s):  
Renal Failure ◽  
Chronic Renal Failure ◽  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Event Related Potentials ◽  
Long Latency ◽  
Related Potentials ◽  
Visual Evoked

Event-related potentials in an invertebrate: crayfish emit ‘omitted stimulus potentials’

2001 ◽  
Vol 204 (24) ◽  
pp. 4291-4300
Author(s):  
Fidel Ramón ◽  
Oscar H. Hernández ◽  
Theodore H. Bullock
Keyword(s):  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Internal State ◽  
Light Flash ◽  
Optic Tract ◽  
Event Related Potentials ◽  
Ambient Light ◽  
Stimulus Interval ◽  
Related Potentials ◽  
Visual Evoked

SUMMARY Electrical signs of neural activity correlated with stimuli or states include a subclass called event-related potentials. These overlap with, but can often be distinguished from, simple stimulus-bound evoked potentials by their greater dependence on endogenous (internal state) factors. Studied mainly in humans, where they are commonly associated with cognition, they are considered to represent objective signs of moderately high-level brain processing. We tested the hypothesis that invertebrates lack such signs by looking in the crayfish Procambarus clarkii for a class of OFF-effects shown in humans to index expectancy. Disproving the hypothesis, we find, using chronic, implanted preparations, that a good omitted stimulus potential is reliably present. The system learns in a few cycles of a regularly repeated light flash to expect one on schedule. Omitted stimulus potentials are found in the protocerebrum, the circumesophageal connective and in the optic tract – perhaps arising in the retina, as in vertebrates. These potentials can be very local and can include loci with and without direct visual evoked potentials in response to each flash. In some loci, the omitted stimulus potential has a slow wave component, in others only a spike burst. Omitted stimulus potentials are more endogenous than visual evoked potentials, with little dependence on flash or ambient light intensity or on train duration. They vary little in size at different times of the day, but abruptly fail to appear if the ambient light is cut off. They can occur during walking, eating or the maintained defense posture but are diminished by ‘distraction’ and are often absent from an inert crayfish until it is aroused. We consider this form of apparent expectation of a learned rhythm (a property that makes it ‘cognitive’ in current usage), to be one of low level, even though some properties suggest endogenous factors. The flashes in a train have an inhibitory effect on a circuit that quickly ‘learns’ the stimulus interval so that the omitted stimulus potential, ready to happen after the learned interval, is prevented by each flash, until released by a missing stimulus.

Electrophysiology in developmental populations: Key methods and findings

2020 ◽  
Author(s):  
Ryan Barry-Anwar ◽  
Tracy Riggins ◽  
Lisa S. Scott
Keyword(s):  
Steady State ◽  
Evoked Potentials ◽  
Human Development ◽  
Visual Evoked Potentials ◽  
Event Related Potentials ◽  
Eeg Signal ◽  
Electrophysiological Studies ◽  
Related Potentials ◽  
Electroencephalogram Eeg ◽  
Electrophysiological Methods

This chapter aims to provide a methodological and empirical overview of electrophysiological techniques used to study human development including: 1) electroencephalogram (EEG), 2) event-related potentials (ERPs), and 3) steady-state visual evoked potentials (ssVEPs). This overview is written to encourage the use of multiple techniques in electrophysiological studies of development. The chapter begins with an introduction to electrophysiological methods and the underlying neural events that give rise to the EEG signal. Second, each technique is described and important electrophysiological empirical contributions to our understanding of development from infancy through childhood and into adolescence are highlighted. Third, considerations and recommendations for the collection, processing, analysis, and publication of developmental electrophysiological data are discussed. Finally, the chapter ends with a look at the future of electrophysiology for the study of development.

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 DBS Artifact Removal Through Template Subtraction

2020 ◽  
Vol 21 (2) ◽  
Author(s):  
Marco Emilio Vazquez ◽  
Enrico Opri ◽  
Brandon Parks ◽  
Gunduz Aysegul
Keyword(s):  
Adaptive Filters ◽  
Physiological Responses ◽  
Event Related Potentials ◽  
Field Potentials ◽  
Large Signal ◽  
Function Fitting ◽  
Electrophysiological Recordings ◽  
Challenging Research ◽  
Related Potentials ◽  
Deep Brain

Deep Brain Stimulation (DBS) typically results in the formation of large signal artifacts in electrophysiological recordings in the surrounding regions of the stimulated area. This can prove to be problematic, as it makes the study of physiological responses in Local Field Potentials (LFPs), and consequently Event Related Potentials (ERPs) quite challenging. Research has been done in attempts to attenuate the effects of these large artifacts through various ways, most commonly through blind suppression, function fitting, template subtraction, and adaptive filters. However, many of these methods have proven to only be useful within the context of surface recordings (EEGs) and not for LFPs. In our research, we utilize template subtraction and extend it to the context of LFPs, in an attempt to uncover more effectively the underlying physiological responses to DBS.

scholarly journals PARIETAL CONTRIBUTIONS TO ABSTRACT NUMEROSITY MEASURED WITH STEADY STATE VISUAL EVOKED POTENTIALS

2020 ◽  
Author(s):  
Peter J. Kohler ◽  
Elham Barzegaran ◽  
Anthony M. Norcia ◽  
Bruce D. McCandliss
Keyword(s):  
Steady State ◽  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Distance Effect ◽  
Event Related Potentials ◽  
Occipital Cortex ◽  
Transient Event ◽  
Related Potentials ◽  
Symbolic Number ◽  
Visual Evoked

AbstractNon-symbolic number changes produce transient Event Related Potentials over parietal electrodes, while numerosity effects measured with Steady-State Visual Evoked Potentials (SSVEPs) appear to originate in occipital cortex. We hypothesized that the stimulation rates used in previous SSVEP studies may be too rapid to drive parietal numerosity mechanisms. Here we recorded SSVEPs and behavioral reports over a slower range of temporal frequencies than previously used. Isoluminant dot stimuli updated at a consistent “carrier” frequency (3-6 Hz) while periodic changes in numerosity (e.g. 8→5) formed an even slower “oddball” frequency (0.5-1 Hz). Each numerosity oddball condition had a matched control condition where the number of dots did not change. Carrier frequencies induced SSVEPs with midline occipital topographies that did not differentiate the presence or absence of numerosity oddballs. By contrast, SSVEPs at oddball frequencies had parietal topographies and responded more strongly when oddballs were present. Consistent with our hypothesis, numerosity effects were stronger at slower stimulation rates. In a second study, the numerosity change was either supra-threshold (e.g. 8→5 dots) or near the threshold required for detecting numerosity changes (e.g. 8→9 dots). We found robust parietal responses for the supra-threshold case only, indicating a numerical distance effect. A third study replicated the parietal oddball SSVEP effect across four distinct suprathreshold numerosity-change conditions and showed that number change direction does not influence the effect. These findings show that SSVEP oddball paradigms can probe parietal computations of abstract numerosity, and may provide a rapid, portable approach to quantifying number sense within educational settings.

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