scholarly journals Early information processing contributions to object individuation revealed by perception of illusory figures

2016 ◽  
Vol 116 (6) ◽  
pp. 2513-2522 ◽  
Author(s):  
Claire K. Naughtin ◽  
Jason B. Mattingley ◽  
Paul E. Dux
Keyword(s):  
Information Processing ◽  
Time Course ◽  
Empirical Work ◽  
Event Related Potentials ◽  
Stimulus Onset ◽  
Processing Stage ◽  
Object Individuation ◽  
Related Potentials ◽  
Physical Elements ◽  
Task Irrelevant

To isolate multiple coherent objects from their surrounds, each object must be represented as a stable perceptual entity across both time and space. Recent theoretical and empirical work has proposed that this process of object individuation is a mid-level operation that emerges around 200–300 ms after stimulus onset. However, this hypothesis is based on paradigms that have potentially obscured earlier effects. Furthermore, no study to date has directly assessed whether object individuation occurs for task-irrelevant objects. In the present study we used electroencephalography (EEG) to measure the time course of individuation, for stimuli both within and outside the focus of attention, to assess the information processing stage at which object individuation arises for both types of objects. We developed a novel paradigm involving items defined by illusory contours, which allowed us to vary the number of to-be-individuated objects while holding the physical elements of the display constant (a design characteristic not present in earlier work). As early as 100 ms after stimulus onset, event-related potentials tracked the number of objects in the attended hemifield, but not those in the unattended hemifield. By contrast, both attended and unattended objects could be individuated at a later stage. Our findings challenge recent conceptualizations of the time course of object individuation and suggest that this process arises earlier for attended than unattended items, implying that voluntary spatial attention influences the time course of this operation.

Activation of Preexisting and Acquired Face Representations: The N250 Event-related Potential as an Index of Face Familiarity

2006 ◽  
Vol 18 (9) ◽  
pp. 1488-1497 ◽  
Author(s):  
James W. Tanaka ◽  
Tim Curran ◽  
Albert L. Porterfield ◽  
Daniel Collins
Keyword(s):  
Time Course ◽  
Event Related Potentials ◽  
Stimulus Onset ◽  
Event Related Potential ◽  
Same Sex ◽  
Face Representation ◽  
Learning Conditions ◽  
Electrophysiological Studies ◽  
Related Potentials ◽  
Face Stimuli

Electrophysiological studies using event-related potentials have demonstrated that face stimuli elicit a greater negative brain potential in right posterior recording sites 170 msec after stimulus onset (N170) relative to nonface stimuli. Results from repetition priming paradigms have shown that repeated exposures of familiar faces elicit a larger negative brainwave (N250r) at inferior temporal sites compared to repetitions of unfamiliar faces. However, less is known about the time course and learning conditions under which the N250 face representation is acquired. In the familiarization phase of the Joe/no Joe task, subjects studied a target “Joe” face (“Jane” for female subjects) and, during the course of the experiment, identified a series of sequentially presented faces as either Joe or not Joe. The critical stimulus conditions included the subject's own face, a same-sex Joe ( Jane) face and a same-sex “other” face. The main finding was that the subject's own face produced a focal negative deflection (N250) in posterior channels relative to nontarget faces. The task-relevant Joe target face was not differentiated from other nontarget faces in the first half of the experiment. However, in the second half, the Joe face produced an N250 response that was similar in magnitude to the own face. These findings suggest that the N250 indexes two types of face memories: a preexperimentally familiar face representation (i.e., the “own face” and a newly acquired face representation (i.e., the Joe/Jane face) that was formed during the course of the experiment.

scholarly journals Temporal expectations modulate face image repetition suppression as indexed by event-related potentials

2018 ◽  
Author(s):  
Daniel Feuerriegel ◽  
Owen Churches ◽  
Scott Coussens ◽  
Hannah A.D. Keage
Keyword(s):  
Time Course ◽  
Predictive Coding ◽  
Event Related Potentials ◽  
Stimulus Onset ◽  
Face Image ◽  
Repetition Effects ◽  
Temporal Expectation ◽  
Repetition Suppression ◽  
Test Face ◽  
Related Potentials

AbstractRepeated exposure to a stimulus leads to reduced responses of stimulus-selective sensory neurons, an effect known as repetition suppression or stimulus-specific adaptation. Several influential models have been proposed to explain repetition suppression within hierarchically-organised sensory systems, with each specifying different mechanisms underlying repetition effects. We manipulated temporal expectations within a face repetition experiment to test a critical prediction of the predictive coding model of repetition suppression: that repetition effects will be larger following stimuli that appear at expected times compared to stimuli that appear at unexpected times. We recorded event-related potentials from 18 participants and mapped the spatiotemporal progression of repetition effects using mass univariate analyses. We then assessed whether the magnitudes of observed face image repetition effects were influenced by temporal expectations. In each trial participants saw an adapter face, followed by a 500ms or 1000ms interstimulus interval (ISI), and then a test face, which was the same or a different face identity to the adapter. Participants’ expectations for whether the test face would appear after a 500ms ISI were cued by the sex of the adapter face. Our analyses revealed multiple repetition effects with distinct scalp topographies, extending until at least 800ms from stimulus onset. An early (158-203ms) repetition effect was larger for stimuli following surprising, rather than expected, 500ms ISI durations, contrary to the model predictions of the predictive coding model of repetition suppression. Later (230-609ms) repetition effects tended to be larger following expected stimulus onset times, in line with predictive coding models. Our results indicate that the relationship between repetition suppression and temporal expectation differs across the time course of the stimulus-evoked response, suggesting multiple distinct mechanisms driving repetition suppression that operate at different latencies within the visual hierarchy.Highlights- Multiple face image repetition effects identified from 162-800ms post stimulus onset- Temporal expectations influenced the magnitudes of repetition effects- Temporal expectation effects differed for early and late stimulus-evoked responses

Modulation of forgiveness on processing hurt situations: A study of event-related potentials

2018 ◽  
Vol 46 (4) ◽  
pp. 607-616
Author(s):  
Yangen Zhou ◽  
Jiamei Lu ◽  
Xiaochen Tang ◽  
Chaoyi Hu ◽  
Haibin Wang
Keyword(s):  
Information Processing ◽  
University Students ◽  
Late Stage ◽  
Time Course ◽  
Event Related Potentials ◽  
Positive Component ◽  
Late Positive Component ◽  
Stimulus Evaluation ◽  
Related Potentials ◽  
The Brain

To explore the neuro-mechanism of the time course of processing a hurt situation, we analyzed event-related potentials (ERPs) generated in the brain in response to stimuli in individuals with different degrees of forgiveness. Participants were 216 university students. Of the early ERP components, the negative-deflecting N1 was modulated neither by degree of forgiveness nor by the hurt situation, and the positive-deflecting P2 was larger for low-forgiveness than for high-forgiveness participants, and for low-hurt than for high-hurt situations. The N2, which identifies and encodes stimulus, was enhanced in the high-forgiveness group and for high-hurt situations. Importantly, the late positive component (LPC) stage of stimulus evaluation was larger in the high-forgiveness group for high-hurt situations, but in the low-forgiveness group was evident for low-hurt situations. These data indicate that the modulation of forgiveness on processing hurt situations occurs at the late stage of information processing.

Orienting and Focusing in Voluntary and Involuntary Visuospatial Attention Conditions

2010 ◽  
Vol 24 (3) ◽  
pp. 198-209 ◽  
Author(s):  
Yan Wang ◽  
Jianhui Wu ◽  
Shimin Fu ◽  
Yuejia Luo
Keyword(s):  
Gain Control ◽  
Event Related Potentials ◽  
Stimulus Onset ◽  
Orientation Discrimination ◽  
Involuntary Attention ◽  
Attention Condition ◽  
Voluntary Attention ◽  
Visual Spatial ◽  
Related Potentials ◽  
Underlying Mechanisms

In the present study, we used event-related potentials (ERPs) and behavioral measurements in a peripherally cued line-orientation discrimination task to investigate the underlying mechanisms of orienting and focusing in voluntary and involuntary attention conditions. Informative peripheral cue (75% valid) with long stimulus onset asynchrony (SOA) was used in the voluntary attention condition; uninformative peripheral cue (50% valid) with short SOA was used in the involuntary attention condition. Both orienting and focusing were affected by attention type. Results for attention orienting in the voluntary attention condition confirmed the “sensory gain control theory,” as attention enhanced the amplitude of the early ERP components, P1 and N1, without latency changes. In the involuntary attention condition, compared with invalid trials, targets in the valid trials elicited larger and later contralateral P1 components, and smaller and later contralateral N1 components. Furthermore, but only in the voluntary attention condition, targets in the valid trials elicited larger N2 and P3 components than in the invalid trials. Attention focusing in the involuntary attention condition resulted in larger P1 components elicited by targets in small-cue trials compared to large-cue trials, whereas in the voluntary attention condition, larger P1 components were elicited by targets in large-cue trials than in small-cue trials. There was no interaction between orienting and focusing. These results suggest that orienting and focusing of visual-spatial attention are deployed independently regardless of attention type. In addition, the present results provide evidence of dissociation between voluntary and involuntary attention during the same task.

Event-Related Potentials in Psychiatry: Approaches to Research and Clinical Applications

1983 ◽  
Vol 17 (4) ◽  
pp. 307-318 ◽  
Author(s):  
H. G. Stampfer
Keyword(s):  
Information Processing ◽  
Psychiatric Disorders ◽  
Rapid Development ◽  
Event Related Potentials ◽  
Clinical Applications ◽  
Direct Access ◽  
Practical Application ◽  
Clinical Methods ◽  
Related Potentials ◽  
The Brain

This article suggests that the potential usefulness of event-related potentials in psychiatry has not been fully explored because of the limitations of various approaches to research adopted to date, and because the field is still undergoing rapid development. Newer approaches to data acquisition and methods of analysis, combined with closer co-operation between medical and physical scientists, will help to establish the practical application of these signals in psychiatric disorders and assist our understanding of psychophysiological information processing in the brain. Finally, it is suggested that psychiatrists should seek to understand these techniques and the data they generate, since they provide more direct access to measures of complex cerebral processes than current clinical methods.

scholarly journals Characterizing pinprick-evoked brain potentials before and after experimentally induced secondary hyperalgesia

2015 ◽  
Vol 114 (5) ◽  
pp. 2672-2681 ◽  
Author(s):  
Emanuel N. van den Broeke ◽  
André Mouraux ◽  
Antonia H. Groneberg ◽  
Doreen B. Pfau ◽  
Rolf-Detlef Treede ◽  
...  
Keyword(s):  
Event Related Potentials ◽  
Stimulus Onset ◽  
Secondary Hyperalgesia ◽  
Brain Potentials ◽  
Nociceptive Pathways ◽  
Before And After ◽  
Pain Ratings ◽  
Related Potentials ◽  
Positive Complex ◽  
Stimulation Of

Secondary hyperalgesia is believed to be a key feature of “central sensitization” and is characterized by enhanced pain to mechanical nociceptive stimuli. The aim of the present study was to characterize, using EEG, the effects of pinprick stimulation intensity on the magnitude of pinprick-elicited brain potentials [event-related potentials (ERPs)] before and after secondary hyperalgesia induced by intradermal capsaicin in humans. Pinprick-elicited ERPs and pinprick-evoked pain ratings were recorded in 19 healthy volunteers, with mechanical pinprick stimuli of varying intensities (0.25-mm probe applied with a force extending between 16 and 512 mN). The recordings were performed before (T0) and 30 min after (T1) intradermal capsaicin injection. The contralateral noninjected arm served as control. ERPs elicited by stimulation of untreated skin were characterized by 1) an early-latency negative-positive complex peaking between 120 and 250 ms after stimulus onset (N120-P240) and maximal at the vertex and 2) a long-lasting positive wave peaking 400–600 ms after stimulus onset and maximal more posterior (P500), which was correlated to perceived pinprick pain. After capsaicin injection, pinprick stimuli were perceived as more intense in the area of secondary hyperalgesia and this effect was stronger for lower compared with higher stimulus intensities. In addition, there was an enhancement of the P500 elicited by stimuli of intermediate intensity, which was significant for 64 mN. The other components of the ERPs were unaffected by capsaicin. Our results suggest that the increase in P500 magnitude after capsaicin is mediated by facilitated mechanical nociceptive pathways.

Endophenotypes and Diagnostic Categories: Event-related Potentials and the Schizophrenia-bipolar Dichotomy

2009 ◽  
Vol 24 (S1) ◽  
pp. 1-1
Author(s):  
J. Maltez ◽  
D. Dias ◽  
H. Silva
Keyword(s):  
Information Processing ◽  
Mental Disorders ◽  
Brain Structure ◽  
Brain Function ◽  
Event Related Potentials ◽  
Intermediate Level ◽  
Special Focus ◽  
Diagnostic Categories ◽  
Biologic Markers ◽  
Related Potentials

After decades of neuroscientific research and taxonomic endeavour in psychiatry the quest for biologic markers specific enough to accommodate nosologic categories has not succeeded. Yet, neurophysiology and neuroimaging have developed pwoerful tools to investigate brain function. An immense amount of data has been accumulated regarding normal and pathologic information processing, cognition, emotion and other domains. Some have been correlated with genes underpinning diseases and are candidate endophenotypes. These stand at an intermediate level between genes and phenotype. They encompass several kinds of dysfunctions or abnormalities in brain structure. Rather than matching to singular diagnostic categories, as we devise them today, the same endophenotype is usually shared by distinct pathologic entities. Assuming tha they reflect specif dysfunctions this raises critical questions regarding the DSM way of classifying mental disorders and to the understanding of the neurobiologic phenomena underlying them. It is the purpose of this presentation to discuss these questions and review some of the data, including our own, concerning event-related potentials endophenotypes of psychosis with special focus on the schizophrenia-bipolar dichotomy and present.

scholarly journals ERP Evidence for a Sex-Specific Stroop Effect in Emotional Speech

2003 ◽  
Vol 15 (8) ◽  
pp. 1135-1148 ◽  
Author(s):  
Annett Schirmer ◽  
Sonja A. Kotz
Keyword(s):  
Semantic Processing ◽  
Event Related Potentials ◽  
Behavioral Effect ◽  
Emotional Prosody ◽  
Emotional Speech ◽  
Emotional Stimuli ◽  
Emotional Information ◽  
Men And Women ◽  
Related Potentials ◽  
Task Irrelevant

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.

scholarly journals Auditory attention alterations in migraine: a behavioral and MEG/EEG study

2019 ◽  
Author(s):  
Rémy Masson ◽  
Yohana Lévêque ◽  
Geneviève Demarquay ◽  
Hesham ElShafei ◽  
Lesly Fornoni ◽  
...  
Keyword(s):  
Event Related Potentials ◽  
Orienting Response ◽  
List Type ◽  
Top Down ◽  
Attention Task ◽  
Bottom Up ◽  
Attentional Processes ◽  
Related Potentials ◽  
The Right ◽  
Task Irrelevant

AbstractObjectivesTo evaluate alterations of top-down and/or bottom-up attention in migraine and their cortical underpinnings.Methods19 migraineurs between attacks and 19 matched control participants performed a task evaluating jointly top-down and bottom-up attention, using visually-cued target sounds and unexpected task-irrelevant distracting sounds. Behavioral responses and MEG/EEG were recorded. Event-related potentials and fields (ERPs/ERFs) were processed and source reconstruction was applied to ERFs.ResultsAt the behavioral level, neither top-down nor bottom-up attentional processes appeared to be altered in migraine. However, migraineurs presented heightened evoked responses following distracting sounds (orienting component of the N1 and Re-Orienting Negativity, RON) and following target sounds (orienting component of the N1), concomitant to an increased recruitment of the right temporo-parietal junction. They also displayed an increased effect of the cue informational value on target processing resulting in the elicitation of a negative difference (Nd).ConclusionsMigraineurs appear to display increased bottom-up orienting response to all incoming sounds, and an enhanced recruitment of top-down attention.SignificanceThe interictal state in migraine is characterized by an exacerbation of the orienting response to attended and unattended sounds. These attentional alterations might participate to the peculiar vulnerability of the migraine brain to all incoming stimuli.HighlightsMigraineurs performed as well as healthy participants in an attention task.However, EEG markers of both bottom-up and top-down attention are increased.Migraine is also associated with a facilitated recruitment of the right temporo-parietal junction.

Neural Biases to Covert and Overt Signals of Fear: Dissociation by Trait Anxiety and Depression

2007 ◽  
Vol 19 (10) ◽  
pp. 1595-1608 ◽  
Author(s):  
Leanne M. Williams ◽  
Andrew H. Kemp ◽  
Kim Felmingham ◽  
Belinda J. Liddell ◽  
Donna M. Palmer ◽  
...  
Keyword(s):  
Trait Anxiety ◽  
Time Course ◽  
Event Related Potentials ◽  
Anxiety And Depression ◽  
Controlled Processing ◽  
Parallel Networks ◽  
Related Potentials ◽  
Conscious Attention ◽  
The Impact ◽  
Emotion Encoding

Although biases toward signals of fear may be an evolutionary adaptation necessary for survival, heightened biases may be maladaptive and associated with anxiety or depression. In this study, event-related potentials (ERPs) were used to examine the time course of neural responses to facial fear stimuli (versus neutral) presented overtly (for 500 msec with conscious attention) and covertly (for 10 msec with immediate masking to preclude conscious awareness) in 257 nonclinical subjects. We also examined the impact of trait anxiety and depression, assessed using psychometric ratings, on the time course of ERPs. In the total subject group, controlled biases to overtly processed fear were reflected in an enhancement of ERPs associated with structural encoding (120–220 msec) and sustained evaluation persisting from 250 msec and beyond, following a temporo-occipital to frontal topography. By contrast, covert fear processing elicited automatic biases, reflected in an enhancement of ERPs prior to structural encoding (80–180 msec) and again in the period associated with automatic orienting and emotion encoding (230–330 msec), which followed the reverse frontal to temporo-occipital topography. Higher levels of trait anxiety (in the clinical range) were distinguished by a heightened bias to covert fear (speeding of early ERPs), compared to higher depression which was associated with an opposing bias to overt fear (slowing of later ERPs). Anxiety also heightened early responses to covert fear, and depression to overt fear, with subsequent deficits in emotion encoding in each case. These findings are consistent with neural biases to signals of fear which operate automatically and during controlled processing, feasibly supported by parallel networks. Heightened automatic biases in anxiety may contribute to a cycle of hypervigilance and anxious thoughts, whereas depression may represent a “burnt out” emotional state in which evaluation of fear stimuli is prolonged only when conscious attention is allocated.

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