Cognitive performance and event-related brain potentials under simulated high altitudes

1993 ◽  
Vol 74 (4) ◽  
pp. 1735-1741 ◽  
Author(s):  
M. Kida ◽  
A. Imai

The effects of hypobaric hypoxia on cognitive processing in humans were studied by recording event-related potentials (ERPs) from the scalp in a go/no-go reaction time (RT) paradigm under various simulated high altitudes. Most subjects indicated abrupt impairment of RT at high altitudes. RTs lengthened in association with changes in latency and amplitude of the N2-P3 components, reflecting sensory discrimination and evaluation processes. Some subjects did not suffer any changes in RT up to an extremely high altitude of 6,000 m. In the latter case, although the N2-P3 components did not undergo any changes, the P3 component was followed by a sequence of negative on-going (frontal maximum) and positive on-going (parietal maximum) slow waves. The amplitudes of these slow waves increased as altitude increased. Although these same waves appeared in the ERPs of subjects who demonstrated the increase in RTs at high altitudes, when the subjects failed in the RT task, both of the slow waves either disappeared or diminished. Such slow waves may be associated with attempts to maintain RTs against the deteriorative effects of hypobaric hypoxia.

2016 ◽  
Vol 311 (1) ◽  
pp. R33-R38 ◽  
Author(s):  
Manabu Shibasaki ◽  
Mari Namba ◽  
Misaki Oshiro ◽  
Craig G. Crandall ◽  
Hiroki Nakata

The effect of hyperthermia on cognitive function remains equivocal, perhaps because of methodological discrepancy. Using electroencephalographic event-related potentials (ERPs), we tested the hypothesis that a passive heat stress impairs cognitive processing. Thirteen volunteers performed repeated auditory oddball paradigms under two thermal conditions, normothermic time control and heat stress, on different days. For the heat stress trial, these paradigms were performed at preheat stress (i.e., normothermic) baseline, when esophageal temperature had increased by ∼0.8°C, when esophageal temperature had increased by ∼2.0°C, and during cooling following the heat stress. The reaction time and ERPs were recorded in each session. For the time control trial, subjects performed the auditory oddball paradigms at approximately the same time interval as they did in the heat stress trial. The peak latency and amplitude of an indicator of auditory processing (N100) were not altered regardless of thermal conditions. An indicator of stimulus classification/evaluation time (latency of P300) and the reaction time were shortened during heat stress; moreover an indicator of cognitive processing (the amplitude of P300) was significantly reduced during severe heat stress (8.3 ± 1.3 μV) relative to the baseline (12.2 ± 1.0 μV, P < 0.01). No changes in these indexes occurred during the time control trial. During subsequent whole body cooling, the amplitude of P300 remained reduced, and the reaction time and latency of P300 remained shortened. These results suggest that excessive elevations in internal temperature reduce cognitive processing but promote classification time.


2006 ◽  
Vol 20 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Bruce D. Dick ◽  
John F. Connolly ◽  
Michael E. Houlihan ◽  
Patrick J. McGrath ◽  
G. Allen Finley ◽  
...  

Abstract: Previous research has found that pain can exert a disruptive effect on cognitive processing. This experiment was conducted to extend previous research with participants with chronic pain. This report examines pain's effects on early processing of auditory stimulus differences using the Mismatch Negativity (MMN) in healthy participants while they experienced experimentally induced pain. Event-related potentials (ERPs) were recorded using target and standard tones whose pitch differences were easy- or difficult-to-detect in conditions where participants attended to (active attention) or ignored (passive attention) the stimuli. Both attention manipulations were conducted in no pain and pain conditions. Experimentally induced ischemic pain did not disrupt the MMN. However, MMN amplitudes were larger to difficult-to-detect deviant tones during painful stimulation when they were attended than when they were ignored. Also, MMN amplitudes were larger to the difficult- than to the easy-to-detect tones in the active attention condition regardless of pain condition. It appears that rather than exerting a disruptive effect, the presence of experimentally induced pain enhanced early processing of small stimulus differences in these healthy participants.


2014 ◽  
Vol 33 (10) ◽  
pp. 723-727
Author(s):  
M. Westermann ◽  
I. W. Husstedt ◽  
A. Okegwo ◽  
S. Evers

SummaryEvent-related potentials (ERP) are regarded as age dependent. However, it is not known whether this is an intrinsic property of ERP or an extrinsic factor. We designed a setting in which ERP were evoked using a modified oddball paradigm with highly differentiable and detectable target and non-target stimuli. A total of 98 probands were enrolled in this study. We evaluated the latency and amplitude of the P3 component of visually evoked ERP. The mean P3 latency was 294 ± 28 ms and was not related to age (r = –0.089; p = 0.382; Spearman-rank-correlation). The P3 amplitude was related to age in the total sample (r = –0.323; p = 0.001; Spearmanrank-correlation) but not in the probands under the age of 60 years. There were no significant differences regarding sex. Our findings suggest that ERP are not age dependent if highly differentiable and detectable stimuli are used. This should be considered when normal values of ERP are created for clinical use.


2015 ◽  
Vol 27 (5) ◽  
pp. 1017-1028 ◽  
Author(s):  
Paul Metzner ◽  
Titus von der Malsburg ◽  
Shravan Vasishth ◽  
Frank Rösler

Recent research has shown that brain potentials time-locked to fixations in natural reading can be similar to brain potentials recorded during rapid serial visual presentation (RSVP). We attempted two replications of Hagoort, Hald, Bastiaansen, and Petersson [Hagoort, P., Hald, L., Bastiaansen, M., & Petersson, K. M. Integration of word meaning and world knowledge in language comprehension. Science, 304, 438–441, 2004] to determine whether this correspondence also holds for oscillatory brain responses. Hagoort et al. reported an N400 effect and synchronization in the theta and gamma range following world knowledge violations. Our first experiment (n = 32) used RSVP and replicated both the N400 effect in the ERPs and the power increase in the theta range in the time–frequency domain. In the second experiment (n = 49), participants read the same materials freely while their eye movements and their EEG were monitored. First fixation durations, gaze durations, and regression rates were increased, and the ERP showed an N400 effect. An analysis of time–frequency representations showed synchronization in the delta range (1–3 Hz) and desynchronization in the upper alpha range (11–13 Hz) but no theta or gamma effects. The results suggest that oscillatory EEG changes elicited by world knowledge violations are different in natural reading and RSVP. This may reflect differences in how representations are constructed and retrieved from memory in the two presentation modes.


2005 ◽  
Vol 100 (1) ◽  
pp. 129-134 ◽  
Author(s):  
Michela Balconi

The present research compared the semantic information processing of linguistic stimuli with semantic elaboration of nonlinguistic facial stimuli. To explore brain potentials (ERPs, event-related potentials) related to decoding facial expressions and the effect of semantic valence of the stimulus, we analyzed data for 20 normal subjects ( M age = 23.6 yr., SD = 0.2). Faces with three basic emotional expressions (fear, happiness, and sadness from the 1976 Ekman and Friesen database), with three semantically anomalous expressions (with respect to their emotional content), and the neutral stimuli (face without an emotional content) were presented in a random order. Differences in peak amplitude of ERP were observed later for anomalous expressions compared with congruous expressions. In fact, the results demonstrated that the emotional anomalous faces elicited a higher negative peak at about 360 msec., distributed mainly over the posterior sites. The observed electrophysiological activity may represent specific cognitive processing underlying the comprehension of facial expressions in detection of semantic anomaly. The evidence is in favour of comparability of this negative deflection with the N400 ERP effect elicited by linguistic anomalies.


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 ◽  
...  

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.


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