Scented Envelopment and ERP Basis Waves

1991 ◽  
Vol 3 (2) ◽  
pp. 128-130
Author(s):  
Yasuhiko Saito ◽  
◽  
Takuji Yamamoto ◽  
S Kanamura ◽  
Keyword(s):  
Contingent Negative Variation ◽  
View Point ◽  
Single Trial ◽  
Brain Potentials ◽  
Positive Basis ◽  
Before And After ◽  
Lemon Oil ◽  
Topographic Characteristics ◽  
Late Positive Complex ◽  
Positive Complex

It has been reported that a brief presentation of odorous stimulus has some effects on Event-related brain potentials (ERPs). In this present study, effects of continuous presentation of odorous stimulus (scented environment) were studies with special references to ERP basis waves which associated to cognitive function. Contingent negative variation (CNV) was recorded before and after continuous presentation of 0.2g lemon oil. ERP basis waves were extracted by Multivariate analysis of single trial CNVs, and it is shown that the ERP basis waves of CNV contained a number of positive components after S1 and S2 of the conventional CNV paradigm. These positive components corresponded from the view point of their latency and topographic characteristics to the late positive complex. In the scented environment by the lemon oil, Sl +350p basis wave, which is a positive basis wave developed 350msec after S1, and S2 +350p, a positive basis wave 350msec after S2, decreased their amplitude significantly and S2 +650p, the second positive basis wave after S2, was also decreased in its amplitude. On the contrary to this, there noted increased amplitude of S1 +500p and S2 +500p in the scented environment. According to the report after the experiment, the odor of lemon oil induced tranquil and hedonic feeling among the subjects and they felt rather relaxed in the scented environment. The effects on the ERP basis waves are thought to be explained along this line of affective changes in the subjects.

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.

Effects of Search Difficulty on the Selection, Maintenance, and Learning of Attentional Templates

2014 ◽  
Vol 26 (9) ◽  
pp. 2042-2054 ◽  
Author(s):  
Eren Gunseli ◽  
Christian N. L. Olivers ◽  
Martijn Meeter
Keyword(s):  
Working Memory ◽  
Search Task ◽  
Memory Storage ◽  
Long Term Memory ◽  
Search Tasks ◽  
Contralateral Delay Activity ◽  
Rate Of Learning ◽  
Late Positive Complex ◽  
Positive Complex

Prominent theories of attention claim that visual search is guided through attentional templates stored in working memory. Recently, the contralateral delay activity (CDA), an electrophysiological index of working memory storage, has been found to rapidly decrease when participants repeatedly search for the same target, suggesting that, with learning, the template moves out of working memory. However, this has only been investigated with pop-out search for distinct targets, for which a strong attentional template may not be necessary. More effortful search tasks might rely more on an active attentional template in working memory, leading to a slower handoff to long-term memory and thus a slower decline of the CDA. Using ERPs, we compared the rate of learning of attentional templates in pop-out and effortful search tasks. In two experiments, the rate of decrease in the CDA was the same for both search tasks. Similar results were found for a second component indexing working memory effort, the late positive complex. However, the late positive complex was also sensitive to anticipated search difficulty, as was expressed in a greater amplitude before the harder search task. We conclude that the amount of working memory effort invested in maintaining an attentional template, but not the rate of learning, depends on search difficulty.

scholarly journals Event-related Potential Signatures of Relational Memory

2006 ◽  
Vol 18 (11) ◽  
pp. 1863-1876 ◽  
Author(s):  
Deborah E. Hannula ◽  
Kara D. Federmeier ◽  
Neal J. Cohen
Keyword(s):  
Eye Movement ◽  
Memory Effects ◽  
Event Related Potential ◽  
Movement Behavior ◽  
Sequential Presentation ◽  
Relational Memory ◽  
Early Processing ◽  
Late Positive Complex ◽  
Positive Complex ◽  
Lines Of Evidence

Various lines of evidence suggest that memory for the relations among arbitrarily paired items acquired prior to testing can influence early processing of a probe stimulus. The event-related potential experiment reported here was designed to explore how early in time memory for a previously established face-scene relationship begins to influence processing of faces, under sequential presentation conditions in which a preview of the scene can promote expectancies about the to-be-presented face. Prior to the current work, the earliest component documented to be sensitive to memory for the relations among arbitrarily paired items was the late positive complex (LPC), but here relational memory effects were evident as early as 270–350 msec after face onset. The latency of these relational memory effects suggests that they may be the precursor to similar effects observed in eye movement behavior. As expected, LPC amplitude was also affected by memory for face-scene relationships, and N400 amplitude reflected some combination of memory for items and memory for the relations among items.

scholarly journals Changes in the Composition of AromatherapeuticCitrusOils during Evaporation

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
George W. Francis ◽  
Yen Thuy Hoang Bui
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Carbonyl Compounds ◽  
Sweet Orange ◽  
Gas Chromatography Mass Spectrometry ◽  
Volatile Components ◽  
Partial Evaporation ◽  
Before And After ◽  
Lemon Oil ◽  
Total Oil

The composition of some commercialCitrusoils, lemon, sweet orange, and tangerine, designated for aromatherapy, was examined before and after partial evaporation in a stream of nitrogen. The intact oils contained the expected mixtures of mono- and sesquiterpenes, with hydrocarbons dominating and lesser amounts of oxygenated analogues making up the remainder. Gas chromatography-mass spectrometry was used to follow alterations in the relative amounts of the various components present as evaporation proceeded. Changes were marked, and in particular more volatile components present in the intact oils rapidly disappeared. Thus the balance of content was shifted away from monoterpene hydrocarbons towards the analogous alcohols and carbonyl compounds. The results of this differential evaporation are discussed and possible consequences for aromatherapy use are noted. The case of lemon oil was especially interesting as the relative amount of citral, a known sensitizer, remaining as time elapsed represented an increasing percentage of the total oil.

scholarly journals A Volume Measurement Method for Lunar Soil Collection Based on a Single Monitoring Camera

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3394
Author(s):  
Shaowen Ding ◽  
Xiaohu Zhang ◽  
Qifeng Yu ◽  
Lichun Li ◽  
Jie Wang
Keyword(s):  
Measurement Method ◽  
Point Clouds ◽  
Lunar Soil ◽  
Volume Measurement ◽  
Design Constraints ◽  
Actual Measurement ◽  
Before And After ◽  
Dense Point ◽  
Monitoring Camera ◽  
Topographic Characteristics

In the task of lunar soil collection, estimating the volume of the collected soil is an important part of the sampling control of the lander. Due to the design constraints of the lander, there is no additional installation position for volume measurement equipment. To fully use the sensors already installed, a collected soil volume measurement method is designed in this paper based only on a single monitoring camera. This method uses a sequence of images of the collection area captured by the camera mounted on the acquisition arm to accurately reconstruct the terrain of the collection area surface before and after soil acquisition. Additionally, bi-temporal dense point clouds are reconstructed. Based on the area of change associated with soil collection, the constructed dense point clouds are compared according to the topographic characteristics of the area to estimate the volume of soil collected. Experiments show that the method is stable and reliable and can meet the requirements of actual measurement tasks.

Separation of the components of the late positive complex in an ERP dishabituation paradigm

2005 ◽  
Vol 116 (10) ◽  
pp. 2363-2380 ◽  
Author(s):  
Jacqueline A. Rushby ◽  
Robert J. Barry ◽  
Rebecca J. Doherty
Keyword(s):  
Late Positive Complex ◽  
Positive Complex
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