Consciousness of attention and expectancy as reflected in event-related potentials and reaction times.

Author(s):  
Werner Sommer ◽  
Juliana Matt ◽  
Hartmut Leuthold
2002 ◽  
Vol 13 (1) ◽  
pp. 69-83 ◽  
Author(s):  
Stefan R. Schweinberger ◽  
Thomas Klos ◽  
Werner Sommer

Abstract: We recorded reaction times (RTs) and event-related potentials (ERPs) in patients with unilateral lesions during a memory search task. Participants memorized faces or abstract words, which were then recognized among new ones. The RT deficit found in patients with left brain damage (LBD) for words increased with memory set size, suggesting that their problem relates to memory search. In contrast, the RT deficit found in patients with RBD for faces was apparently related to perceptual encoding, a conclusion also supported by their reduced P100 ERP component. A late slow wave (720-1720 ms) was enhanced in patients, particularly to words in patients with LBD, and to faces in patients with RBD. Thus, the slow wave was largest in the conditions with most pronounced performance deficits, suggesting that it reflects deficit-related resource recruitment.


2005 ◽  
Vol 84 (3) ◽  
pp. 435-451 ◽  
Author(s):  
Dermot Barnes-Holmes ◽  
Donal Regan ◽  
Yvonne Barnes-Holmes ◽  
Sean Commins ◽  
Derek Walsh ◽  
...  

1999 ◽  
Vol 127 (3) ◽  
pp. 291-297 ◽  
Author(s):  
A. Spantekow ◽  
Paul Krappmann ◽  
Stefan Everling ◽  
Hans Flohr

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Irina Chamine ◽  
Barry S. Oken

Objective. Stress-reducing therapies help maintain cognitive performance during stress. Aromatherapy is popular for stress reduction, but its effectiveness and mechanism are unclear. This study examined stress-reducing effects of aromatherapy on cognitive function using the go/no-go (GNG) task performance and event related potentials (ERP) components sensitive to stress. The study also assessed the importance of expectancy in aromatherapy actions.Methods. 81 adults were randomized to 3 aroma groups (active experimental, detectable, and undetectable placebo) and 2 prime subgroups (prime suggesting stress-reducing aroma effects or no-prime). GNG performance, ERPs, subjective expected aroma effects, and stress ratings were assessed at baseline and poststress.Results. No specific aroma effects on stress or cognition were observed. However, regardless of experienced aroma, people receiving a prime displayed faster poststress median reaction times than those receiving no prime. A significant interaction for N200 amplitude indicated divergent ERP patterns between baseline and poststress for go and no-go stimuli depending on the prime subgroup. Furthermore, trends for beneficial prime effects were shown on poststress no-go N200/P300 latencies and N200 amplitude.Conclusion. While there were no aroma-specific effects on stress or cognition, these results highlight the role of expectancy for poststress response inhibition and attention.


2001 ◽  
Vol 13 (1) ◽  
pp. 121-143 ◽  
Author(s):  
Nicolas Dumay ◽  
Abdelrhani Benraïss ◽  
Brian Barriol ◽  
Cécile Colin ◽  
Monique Radeau ◽  
...  

Phonological priming between bisyllabic (CV.CVC) spoken items was examined using both behavioral (reaction times, RTs) and electrophysiological (event-related potentials, ERPs) measures. Word and pseudoword targets were preceded by pseudoword primes. Different types of final phonological overlap between prime and target were compared. Critical pairs shared the last syllable, the rime or the coda, while unrelated pairs were used as controls. Participants performed a target shadowing task in Experiment 1 and a delayed lexical decision task in Experiment 2. RTs were measured in the first experiment and ERPs were recorded in the second experiment. The RT experiment was carried out under two presentation conditions. In Condition 1 both primes and targets were presented auditorily, while in Condition 2 the primes were presented visually and the targets auditorily. Priming effects were found in the unimodal condition only. RTs were fastest for syllable overlap, intermediate for rime overlap, and slowest for coda overlap and controls that did not differ from one another. ERPs were recorded under unimodal auditory presentation. ERP results showed that the amplitude of the auditory N400 component was smallest for syllable overlap, intermediate for rime overlap, and largest for coda overlap and controls that did not differ from one another. In both experiments, the priming effects were larger for word than for pseudoword targets. These results are best explained by the combined influences of nonlexical and lexical processes, and a comparison of the reported effects with those found in monosyllables suggests the involvement of rime and syllable representations.


1994 ◽  
Vol 6 (3) ◽  
pp. 204-219 ◽  
Author(s):  
Peter Praamstra ◽  
Antje S. Meyer ◽  
Willem J. M. Levelt

Two experiments examined phonological priming effects on reaction times, error rates, and event-related brain potential (ERP) measures in an auditory lexical decision task. In Experiment 1 related prime-target pairs rhymed, and in Experiment 2 they alliterated (i.e., shared the consonantal onset and vowel). Event-related potentials were recorded in a delayed response task. Reaction times and error rates were obtained both for the delayed and an immediate response task. The behavioral data of Experiment 1 provided evidence for phonological facilitation of word, but not of nonword decisions. The brain potentials were more negative to unrelated than to rhyming word-word pairs between 450 and 700 rnsec after target onset. This negative enhancement was not present for word-nonword pairs. Thus, the ERP results match the behavioral data. The behavioral data of Experiment 2 provided no evidence for phonological Facilitation. However, between 250 and 450 msec after target onset, i.e., considerably earlier than in Experiment 1, brain potentials were more negative for unrelated than for alliterating Word-word and word-nonword pairs. It is argued that the ERP effects in the two experiments could be modulations of the same underlying component, possibly the N400. The difference in the timing of the effects is likely to be due to the fact that the shared segments in related stimulus pairs appeared in different word positions in the two experiments.


Author(s):  
Ninfa Amato ◽  
Nilo Riva ◽  
Marco Cursi ◽  
Ana Martins-Silva ◽  
Vittorio Martinelli ◽  
...  

2002 ◽  
Vol 94 (3_suppl) ◽  
pp. 1168-1176 ◽  
Author(s):  
Shulan Hsieh

When participants are asked either to repeat the task from the previous trial or switch to the other task, their reaction times are larger for switched than repeated tasks. This “switch cost” has been repeatedly demonstrated in behavioral studies. In this study, event-related potentials (ERPs) were recorded from 12 healthy college students to assess whether this switch cost reflects component processes of preparation and interference. Analyses of ERPs showed that following the cue, there was greater positivity for a switched relative to a repeated trial when the tasks occurred in a fixed-order rather than in a random-order condition. Following the onset of the stimulus-pair, there was greater negativity for switched relative to repeated trials when the task stimulus consisted of both letters and digits but not when it consisted of either a letter or a digit paired with a neutral character. The data provide neurophysiological evidence for the two component processes.


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