scholarly journals Electrophysiological Correlates of Refreshing: Event-related Potentials Associated with Directing Reflective Attention to Face, Scene, or Word Representations

2015 ◽  
Vol 27 (9) ◽  
pp. 1823-1839 ◽  
Author(s):  
Matthew R. Johnson ◽  
Gregory McCarthy ◽  
Kathleen A. Muller ◽  
Samuel N. Brudner ◽  
Marcia K. Johnson

Refreshing is the component cognitive process of directing reflective attention to one of several active mental representations. Previous studies using fMRI suggested that refresh tasks involve a component process of initiating refreshing as well as the top–down modulation of representational regions central to refreshing. However, those studies were limited by fMRI's low temporal resolution. In this study, we used EEG to examine the time course of refreshing on the scale of milliseconds rather than seconds. ERP analyses showed that a typical refresh task does have a distinct electrophysiological response as compared to a control condition and includes at least two main temporal components: an earlier (∼400 msec) positive peak reminiscent of a P3 response and a later (∼800–1400 msec) sustained positivity over several sites reminiscent of the late directing attention positivity. Overall, the evoked potentials for refreshing representations from three different visual categories (faces, scenes, words) were similar, but multivariate pattern analysis showed that some category information was nonetheless present in the EEG signal. When related to previous fMRI studies, these results are consistent with a two-phase model, with the first phase dominated by frontal control signals involved in initiating refreshing and the second by the top–down modulation of posterior perceptual cortical areas that constitutes refreshing a representation. This study also lays the foundation for future studies of the neural correlates of reflective attention at a finer temporal resolution than is possible using fMRI.

2017 ◽  
Vol 55 ◽  
pp. 46-58 ◽  
Author(s):  
William Francis Turner ◽  
Phillip Johnston ◽  
Kathleen de Boer ◽  
Carmen Morawetz ◽  
Stefan Bode

2009 ◽  
Vol 21 (10) ◽  
pp. 1893-1906 ◽  
Author(s):  
Amy S. Desroches ◽  
Randy Lynn Newman ◽  
Marc F. Joanisse

Behavioral and modeling evidence suggests that words compete for recognition during auditory word identification, and that phonological similarity is a driving factor in this competition. The present study used event-related potentials (ERPs) to examine the temporal dynamics of different types of phonological competition (i.e., cohort and rhyme). ERPs were recorded during a novel picture–word matching task, where a target picture was followed by an auditory word that either matched the target (CONE–cone), or mismatched in one of three ways: rhyme (CONE–bone), cohort (CONE–comb), and unrelated (CONE–fox). Rhymes and cohorts differentially modulated two distinct ERP components, the phonological mismatch negativity and the N400, revealing the influences of prelexical and lexical processing components in speech recognition. Cohort mismatches resulted in late increased negativity in the N400, reflecting disambiguation of the later point of miscue and the combined influences of top–down expectations and misleading bottom–up phonological information on processing. In contrast, we observed a reduction in the N400 for rhyme mismatches, reflecting lexical activation of rhyme competitors. Moreover, the observed rhyme effects suggest that there is an interaction between phoneme-level and lexical-level information in the recognition of spoken words. The results support the theory that both levels of information are engaged in parallel during auditory word recognition in a way that permits both bottom–up and top–down competition effects.


2017 ◽  
Author(s):  
Stefan Bode ◽  
Daniel Feuerriegel ◽  
Daniel Bennett ◽  
Phillip M. Alday

AbstractIn recent years, neuroimaging research in cognitive neuroscience has increasingly used multivariate pattern analysis (MVPA) to investigate higher cognitive functions. Here we present DDTBOX, an open-source MVPA toolbox for electroencephalography (EEG) data. DDTBOX runs under MATLAB and is well integrated with the EEGLAB/ERPLAB and Fieldtrip toolboxes (Delorme and Makeig, 2004; Lopez-Calderon and Luck, 2014; Oostenveld et al. 2011). It trains support vector machines (SVMs) on patterns of event-related potential (ERP) amplitude data, following or preceding an event of interest, for classification or regression of experimental variables. These amplitude patterns can be extracted across space/electrodes (spatial decoding), time (temporal decoding), or both (spatiotemporal decoding). DDTBOX can also extract SVM feature weights, generate empirical chance distributions based on shuffled-labels decoding for group-level statistical testing, provide estimates of the prevalence of decodable information in the population, and perform a variety of corrections for multiple comparisons. It also includes plotting functions for single subject and group results. DDTBOX complements conventional analyses of ERP components, as subtle multivariate patterns can be detected that would be overlooked in standard analyses. It further allows for a more explorative search for information when no ERP component is known to be specifically linked to a cognitive process of interest. In summary, DDTBOX is an easy-to-use and open-source toolbox that allows for characterising the time-course of information related to various perceptual and cognitive processes. It can be applied to data from a large number of experimental paradigms and could therefore be a valuable tool for the neuroimaging community.


2007 ◽  
Vol 40 (05) ◽  
Author(s):  
AH Neuhaus ◽  
TE Goldberg ◽  
Y Hassoun ◽  
JA Bates ◽  
KW Nassauer ◽  
...  

2019 ◽  
Author(s):  
Rémy Masson ◽  
Yohana Lévêque ◽  
Geneviève Demarquay ◽  
Hesham ElShafei ◽  
Lesly Fornoni ◽  
...  

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.


2007 ◽  
Vol 19 (10) ◽  
pp. 1595-1608 ◽  
Author(s):  
Leanne M. Williams ◽  
Andrew H. Kemp ◽  
Kim Felmingham ◽  
Belinda J. Liddell ◽  
Donna M. Palmer ◽  
...  

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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