Brain Activity Underlying Mental Imagery: Event-related Potentials During Mental Image Generation

1989 ◽  
Vol 1 (4) ◽  
pp. 302-316 ◽  
Author(s):  
Martha J. Farah ◽  
Lauren L. Weisberg ◽  
Mark Monheit ◽  
Franck Peronnet
Keyword(s):  
Mental Imagery ◽  
Time Course ◽  
Brain Activity ◽  
Hemispheric Specialization ◽  
Mental Image ◽  
Event Related Potentials ◽  
Image Generation ◽  
Mental Images ◽  
Related Potentials ◽  
Modality Specificity

This article addresses two issues about the neural bases of mental imagery. The first issue concerns the modality-specificity of mental images, that is, whether or not they involve activity in visual areas of the brain. The second issue concerns hemispheric specialization for the generation of mental images. We compared event-related potentials recorded under two conditions: one in which subjects were shown words and asked to read them and one in which subjects were shown words and asked to read them and generate visual mental images of the words' referents. Imagery caused a slow, late positivity, maximal at the occipital and posterior temporal regions of the scalp, relative to the comparison condition, and consistent with the involvement of modality-specific visual cortex in mental imagery. Also noted was an asymmetry in the imagery-related ERP, consistent with left-hemisphere specialization for mental image generation. Similar results were obtained when subjects listened to auditorily presented words with and without instructions to generate mental images. To assess the specificity of the relation between these ERP effects and mental imagery, we compared the ERP changes brought about by imaging with those brought about by another effortful task using the same stimulus words: proofreading the words for occasional misspellings. This produced changes that differed in polarity, time course, and scalp distribution from the imagery-related changes.

Time Course of Brain Activity during Change Blindness and Change Awareness: Performance is Predicted by Neural Events before Change Onset

2006 ◽  
Vol 18 (12) ◽  
pp. 2108-2129 ◽  
Author(s):  
Gilles Pourtois ◽  
Michael De Pretto ◽  
Claude-Alain Hauert ◽  
Patrik Vuilleumier
Keyword(s):  
Change Detection ◽  
Neural Activity ◽  
Time Course ◽  
Brain Activity ◽  
Change Blindness ◽  
Event Related Potentials ◽  
Distinct Pattern ◽  
Event Related Potential ◽  
Related Potentials ◽  
Visual Changes

People often remain “blind” to visual changes occurring during a brief interruption of the display. The processing stages responsible for such failure remain unresolved. We used event-related potentials to determine the time course of brain activity during conscious change detection versus change blindness. Participants saw two successive visual displays, each with two faces, and reported whether one of the faces changed between the first and second displays. Relative to blindness, change detection was associated with a distinct pattern of neural activity at several successive processing stages, including an enhanced occipital P1 response and a sustained frontal activity (CNV-like potential) after the first display, before the change itself. The amplitude of the N170 and P3 responses after the second visual display were also modulated by awareness of the face change. Furthermore, a unique topography of event-related potential activity was observed during correct change and correct no-change reports, but not during blindness, with a recurrent time course in the stimulus sequence and simultaneous sources in the parietal and temporo-occipital cortex. These results indicate that awareness of visual changes may depend on the attentional state subserved by coordinated neural activity in a distributed network, before the onset of the change itself.

Time Course of Error-Potentiated Startle and its Relationship to Error-Related Brain Activity

2013 ◽  
Vol 27 (2) ◽  
pp. 51-59 ◽  
Author(s):  
Anja Riesel ◽  
Anna Weinberg ◽  
Tim Moran ◽  
Greg Hajcak
Keyword(s):  
Time Course ◽  
Flanker Task ◽  
Brain Activity ◽  
Event Related Potentials ◽  
Error Related Negativity ◽  
Aversive Events ◽  
Startle Probe ◽  
Oscillatory Power ◽  
Related Potentials ◽  
Defensive Action

Errors are aversive, motivationally-salient events which prime defensive action. This is reflected in a potentiated startle reflex after the commission of an error. The current study replicates and extends previous work examining the time course of error-potentiated startle as a function of startle lag (i.e., 300 ms or 800 ms following correct and error responses). In addition, the relationship between error-potentiated startle and error-related brain activity in both the temporal (error-related negativity, ERN/Ne) and spectral (error-related theta and delta power) domains was investigated. Event-related potentials (ERPs) were recorded from 32 healthy undergraduates while they performed an arrowhead version of a flanker task. Complex Morlet wavelets were applied to compute oscillatory power in the delta- and theta-band range. Consistent with our previous report, startle was larger following errors. Furthermore, this effect was evident at both early and late startle probe times. Increased delta and theta power after an error was associated with larger error-potentiated startle. An association between ERN amplitude and error-potentiated startle was only observed in a subgroup of individuals with relatively large ERN/Ne amplitude. Among these individuals, ERN/Ne magnitude was also related to multiple indices of task performance. This study further supports the notion that errors are aversive events that prime defensive motivation, and that error-potentiated startle is evident beyond the immediate commission of an error and can be predicted from error-related brain activity.

scholarly journals Disentangling the Independent Contributions of Visual and Conceptual Features to the Spatiotemporal Dynamics of Scene Categorization

2020 ◽  
Author(s):  
Michelle R. Greene ◽  
Bruce C. Hansen
Keyword(s):  
Time Course ◽  
Brain Activity ◽  
Similarity Measures ◽  
Event Related Potentials ◽  
Event Related Potential ◽  
Scene Categorization ◽  
Low Level ◽  
Related Potentials ◽  
Single Fixation ◽  
High Level

AbstractHuman scene categorization is characterized by its remarkable speed. While many visual and conceptual features have been linked to this ability, significant correlations exist between feature spaces, impeding our ability to determine their relative contributions to scene categorization. Here, we employed a whitening transformation to decorrelate a variety of visual and conceptual features and assess the time course of their unique contributions to scene categorization. Participants (both sexes) viewed 2,250 full-color scene images drawn from 30 different scene categories while having their brain activity measured through 256-channel EEG. We examined the variance explained at each electrode and time point of visual event-related potential (vERP) data from nine different whitened encoding models. These ranged from low-level features obtained from filter outputs to high-level conceptual features requiring human annotation. The amount of category information in the vERPs was assessed through multivariate decoding methods. Behavioral similarity measures were obtained in separate crowdsourced experiments. We found that all nine models together contributed 78% of the variance of human scene similarity assessments and was within the noise ceiling of the vERP data. Low-level models explained earlier vERP variability (88 ms post-image onset), while high-level models explained later variance (169 ms). Critically, only high-level models shared vERP variability with behavior. Taken together, these results suggest that scene categorization is primarily a high-level process, but reliant on previously extracted low-level features.Significance StatementIn a single fixation, we glean enough information to describe a general scene category. Many types of features are associated with scene categories, ranging from low-level properties such as colors and contours, to high-level properties such as objects and attributes. Because these properties are correlated, it is difficult to understand each property’s unique contributions to scene categorization. This work uses a whitening transformation to remove the correlations between features and examines the extent to which each feature contributes to visual event-related potentials (vERPs) over time. We found that low-level visual features contributed first, but were not correlated with categorization behavior. High-level features followed 80 ms later, providing key insights into how the brain makes sense of a complex visual world.

scholarly journals Anytime collaborative brain–computer interfaces for enhancing perceptual group decision-making

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saugat Bhattacharyya ◽  
Davide Valeriani ◽  
Caterina Cinel ◽  
Luca Citi ◽  
Riccardo Poli
Keyword(s):  
Decision Making ◽  
Group Decision Making ◽  
Group Decision ◽  
Brain Activity ◽  
Event Related Potentials ◽  
Brain Computer Interfaces ◽  
Appearance Time ◽  
Perceptual Group ◽  
Computer Interfaces ◽  
Related Potentials

AbstractIn this paper we present, and test in two realistic environments, collaborative Brain-Computer Interfaces (cBCIs) that can significantly increase both the speed and the accuracy of perceptual group decision-making. The key distinguishing features of this work are: (1) our cBCIs combine behavioural, physiological and neural data in such a way as to be able to provide a group decision at any time after the quickest team member casts their vote, but the quality of a cBCI-assisted decision improves monotonically the longer the group decision can wait; (2) we apply our cBCIs to two realistic scenarios of military relevance (patrolling a dark corridor and manning an outpost at night where users need to identify any unidentified characters that appear) in which decisions are based on information conveyed through video feeds; and (3) our cBCIs exploit Event-Related Potentials (ERPs) elicited in brain activity by the appearance of potential threats but, uniquely, the appearance time is estimated automatically by the system (rather than being unrealistically provided to it). As a result of these elements, in the two test environments, groups assisted by our cBCIs make both more accurate and faster decisions than when individual decisions are integrated in more traditional manners.

Syntactically Based Sentence Processing Classes: Evidence from Event-Related Brain Potentials

1991 ◽  
Vol 3 (2) ◽  
pp. 151-165 ◽  
Author(s):  
Helen Neville ◽  
Janet L. Nicol ◽  
Andrew Barss ◽  
Kenneth I. Forster ◽  
Merrill F. Garrett
Keyword(s):  
Left Hemisphere ◽  
Sentence Processing ◽  
Brain Activity ◽  
Phrase Structure ◽  
Event Related Potentials ◽  
Negative Potential ◽  
Developmental Studies ◽  
Brain Potentials ◽  
Related Potentials ◽  
Theoretical Considerations

Theoretical considerations and diverse empirical data from clinical, psycholinguistic, and developmental studies suggest that language comprehension processes are decomposable into separate subsystems, including distinct systems for semantic and grammatical processing. Here we report that event-related potentials (ERPs) to syntactically well-formed but semantically anomalous sentences produced a pattern of brain activity that is distinct in timing and distribution from the patterns elicited by syntactically deviant sentences, and further, that different types of syntactic deviance produced distinct ERP patterns. Forty right-handed young adults read sentences presented at 2 words/sec while ERPs were recorded from over several positions between and within the hemispheres. Half of the sentences were semantically and grammatically acceptable and were controls for the remainder, which contained sentence medial words that violated (1) semantic expectations, (2) phrase structure rules, or (3) WH-movement constraints on Specificity and (4) Subjacency. As in prior research, the semantic anomalies produced a negative potential, N400, that was bilaterally distributed and was largest over posterior regions. The phrase structure violations enhanced the N125 response over anterior regions of the left hemisphere, and elicited a negative response (300-500 msec) over temporal and parietal regions of the left hemisphere. Violations of Specificity constraints produced a slow negative potential, evident by 125 msec, that was also largest over anterior regions of the left hemisphere. Violations of Subjacency constraints elicited a broadly and symmetrically distributed positivity that onset around 200 msec. The distinct timing and distribution of these effects provide biological support for theories that distinguish between these types of grammatical rules and constraints and more generally for the proposal that semantic and grammatical processes are distinct subsystems within the language faculty.

Frontal Brain Activity during Episodic and Semantic Retrieval: Insights from Event-Related Potentials

1999 ◽  
Vol 11 (6) ◽  
pp. 598-609 ◽  
Author(s):  
Charan Ranganath ◽  
Ken A. Paller
Keyword(s):  
Prefrontal Cortex ◽  
Memory Retrieval ◽  
Brain Activity ◽  
Novelty Detection ◽  
Event Related Potentials ◽  
Episodic Retrieval ◽  
Semantic Retrieval ◽  
Retrieval Task ◽  
Related Potentials ◽  
The Right

Previous neuropsychological and neuroimaging results have implicated the prefrontal cortex in memory retrieval, although its precise role is unclear. In the present study, we examined patterns of brain electrical activity during retrieval of episodic and semantic memories. In the episodic retrieval task, participants retrieved autobiographical memories in response to event cues. In the semantic retrieval task, participants generated exemplars in response to category cues. Novel sounds presented intermittently during memory retrieval elicited a series of brain potentials including one identifiable as the P3a potential. Based on prior research linking P3a with novelty detection and with the frontal lobes, we predicted that P3a would be reduced to the extent that novelty detection and memory retrieval interfere with each other. Results during episodic and semantic retrieval tasks were compared to results during a task in which subjects attended to the auditory stimuli. P3a amplitudes were reduced during episodic retrieval, particularly at right lateral frontal scalp locations. A similar but less lateralized pattern of frontal P3a reduction was observed during semantic retrieval. These findings support the notion that the right prefrontal cortex is engaged in the service of memory retrieval, particularly for episodic memories.

scholarly journals ERP CORE: An Open Resource for Human Event-Related Potential Research

2020 ◽  
Author(s):  
Emily S. Kappenman ◽  
Jaclyn Farrens ◽  
Wendy Zhang ◽  
Andrew X Stewart ◽  
Steven J Luck
Keyword(s):  
Data Processing ◽  
Brain Activity ◽  
A Priori ◽  
Event Related Potentials ◽  
Event Related Potential ◽  
Error Related Negativity ◽  
Wide Range ◽  
Experiment Control ◽  
Related Potentials

Event-related potentials (ERPs) are noninvasive measures of human brain activity that index a range of sensory, cognitive, affective, and motor processes. Despite their broad application across basic and clinical research, there is little standardization of ERP paradigms and analysis protocols across studies. To address this, we created ERP CORE (Compendium of Open Resources and Experiments), a set of optimized paradigms, experiment control scripts, data processing pipelines, and sample data (N = 40 neurotypical young adults) for seven widely used ERP components: N170, mismatch negativity (MMN), N2pc, N400, P3, lateralized readiness potential (LRP), and error-related negativity (ERN). This resource makes it possible for researchers to 1) employ standardized ERP paradigms in their research, 2) apply carefully designed analysis pipelines and use a priori selected parameters for data processing, 3) rigorously assess the quality of their data, and 4) test new analytic techniques with standardized data from a wide range of paradigms.

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