Psychophysiology (PSYCHOPHYSIOLOGY)

Publications in this journal

• Article: Cardiac awareness and autonomic cardiac reactivity during emotional picture viewing and mental stress

  B.M.Herbert, O.Pollatos, H.Flor, P.Enck, R.Schandry
  Psychophysiology 01/2010; 47:342-54.
• Article: PRESERVED ENCODING OF UNFAMILIAR FACES UNDER HIGH ATTENTIONAL LOAD: ERP EVIDENCE

  Markus F. Neumann, Tarik N. Mohamed, Stefan R. Schweinberger
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  ABSTRACT: According to recent models of selective attention, processing of task-irrelevant stimuli is abolished when attentional resources are fully consumed by task-relevant material (high load). However, task-irrelevant familiar faces can elicit repetition-related neural modulations despite high load at initial presentation (Neumann & Schweinberger, 2008). Although faces may access a face-specific attention resource, it is also possible that the processing of familiar faces requires very little general attention resources. In Experiment 1 we tested whether task-irrelevant unfamiliar faces also elicit repetition modulations under high load. Participants performed a letter identification task by indicating whether an “X” vs. “N” was among 6 different (high load) or 6 identical (low load) letters. Letter strings were superimposed on task-irrelevant faces. Following letter identification, participants detected occasional butterflies among S2 probes, which were either identical repetitions of S1 faces or new faces. ERPs revealed an occipito-temporal N250r-repetition effect to unfamiliar faceat was unaffected by load at S1 presentation. In Experiment 2 we tested whether preserved encoding under high load is specific for faces, employing hands and houses as additional categories. Body parts have been discussed to attract attention in a similar fashion as faces , and therefore appear likely candidates for preserved encoding under high load. However, while N250r-repetition effects were replicated for faces, repetition-related neural modulations were absent under high load for both houses and hands. This strongly suggests that encoding under high load is mediated by a separate face-specific attention resource, which cannot facilitate encoding of body parts or artificial objects.
  Psychophysiology 09/2009; 46(46):S134-S135.
• Article: Sensory detection thresholds are modulated across the cardiac cycle: evidence that cutaneous sensibility is greatest for systolic stimulation.

  L Edwards, C Ring, D McIntyre, J B Winer, U Martin
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  ABSTRACT: The visceral afferent feedback hypothesis proposes that sensorimotor function is impaired by cortical inhibition associated with increased baroreceptor activation. This study is the first to examine the effects of naturally occurring variations in baroreceptor activity across the cardiac cycle on cutaneous sensory detection thresholds. In each trial, an electrocutaneous stimulus was delivered to the index finger at one of three intervals (0, 300, 600 ms) after the R-wave of the electrocardiogram. Separate interleaving up-down staircases were used to determine the 50% detection threshold for each R-wave to stimulation interval. Cutaneous sensory detection thresholds were lower for stimuli presented at R+300 ms than R+0 ms or R+600 ms. The finding that cutaneous sensibility was greater when stimulated during systole than diastole may be accounted for by a modified afferent feedback hypothesis.
  Psychophysiology 02/2009; 46(2):252-6.
• Article: Visual mismatch negativity: new evidence from the equiprobable paradigm.

  Motohiro Kimura, Jun'ichi Katayama, Hideki Ohira, Erich Schröger
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  ABSTRACT: In visual oddball studies, deviant compared to standard stimuli elicited a posterior negative ERP at around 100-250 ms. To determine the underlying processes of the negativity, we used the equiprobable sequence in which bar stimuli of five types of orientation were presented with equal probabilities (control 20% each) as well as the oddball sequence in which two stimuli with the closest orientation were presented with different probabilities (deviant 20% and standard 80%). Deviant compared to standard stimuli elicited two negativities at around 100-150 ms with no hemispheric dominance and 200-250 ms with right hemispheric dominance, while deviant compared to control stimuli elicited only a negativity at around 200-250 ms with right hemispheric dominance. These results suggest that the early negativity reflects refractory effect, while the late negativity reflects memory-comparison-based change detection effect (visual mismatch negativity).
  Psychophysiology 02/2009; 46(2):402-9.
• Article: Prolonged platelet activation in individuals with elevated blood pressure in response to a moderate exercise challenge.

  Suzi Hong, Karen A Adler, Roland Von Känel, Judy Nordberg, Michael G Ziegler, Paul J Mills
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  ABSTRACT: We examined the magnitude of 20-min moderate exercise-induced platelet activation in 50 volunteers with normal (n=31) or elevated blood pressure (EBP; n=19). Blood was drawn before, immediately after, and 25 min after exercise. Antibody-staining for platelet activation markers, P-selectin, and fibrinogen receptors was done with and without adenosine diphosphate (ADP) stimulation in whole blood for flow cytometric analyses. Exercise led to increases in percent aggregated platelets and percent platelets expressing P-selectin or PAC-1 binding (ps< or =.001). This increase in percent platelets expressing P-selectin continued even after a 25-min rest only in the EBP group (p< or =.01) accompanied by an increase in percent of aggregated platelets (p< or =.05). Although ADP stimulation led to increased platelet activation at rest, it was attenuated following exercise, even among EBP individuals. A moderate exercise challenge induced prolonged platelet activation in individuals with EBP but attenuation in activation to further stimulation by an agonist. Findings suggest that a recovery period after physical stress appears critical in individuals with high BP regarding platelet activation and aggregation, which can lead to an acute coronary syndrome in vulnerable individuals.
  Psychophysiology 02/2009; 46(2):276-84.
• Article: Age, physical fitness, and attention: P3a and P3b.

  Matthew B Pontifex, Charles H Hillman, John Polich
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  ABSTRACT: The influence of age and fitness on the neuroelectric correlates of attentional orienting and processing during stimulus discrimination were investigated. Younger and older adult participants completed a maximal aerobic exercise test and were separated into higher- and lower-fit groups according to their cardiorespiratory fitness. Task performance and event-related potential measures were obtained during two- and three-stimulus oddball tasks. Results indicated that fitness may ameliorate or protect against cognitive aging for simple stimulus discriminations. Increases in task difficulty indicated that fitness may not be sufficient to overcome age-related deficits in stimulus discrimination. Further, fitness did not influence attentional orienting. The findings suggest that fitness-related changes in cognitive function may originate from other attentional mechanisms. Theoretical implications are discussed.
  Psychophysiology 02/2009; 46(2):379-87.
• Article: Metabolically exaggerated cardiac reactions to acute psychological stress revisited.

  Douglas Carroll, Anna C Phillips, George M Balanos
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  ABSTRACT: The reactivity hypothesis postulates that large magnitude cardiovascular reactions to psychological stress contribute to the development of pathology. A key but little tested assumption is that such reactions are metabolically exaggerated. Cardiac activity, using Doppler echocardiography, and oxygen consumption, using mass spectrometry, were measured at rest and during and after a mental stress task and during graded submaximal cycling exercise. Cardiac activity and oxygen consumption showed the expected orderly association during exercise. However, during stress, large increases in cardiac activity were observed in the context of modest rises in energy expenditure; observed cardiac activity during stress substantially exceeded that predicted on the basis of contemporary levels of oxygen consumption. Thus, psychological stress can provoke increases in cardiac activity difficult to account for in terms of the metabolic demands of the stress task.
  Psychophysiology 02/2009; 46(2):270-5.
• Article: Disentangling effects of auditory distraction and of stimulus-response sequence.

  Urte Roeber, Stefan Berti, Dagmar Müller, Andreas Widmann, Erich Schröger
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  ABSTRACT: When we pay attention to one task, irrelevant changes may interfere. The effect of changes on behavioral and electrophysiological responses has been studied in two separate research fields: Research on Distraction states that a rare irrelevant change takes attention away from the primary task. Research on Sequences states that any change in stimulus or response incurs a cost or benefit depending on the kind of change. To disentangle distraction from sequence effects, we made task-irrelevant changes rare in one condition and frequent in another while also assessing stimulus and response changes from trial to trial. Participants used key presses to classify syllables presented in two different, irrelevant voice pitches. We found that distraction and sequence interacted to alter reaction times and errors on the primary task and also to alter ERP markers of distraction (P3a). The sequential effects cannot, however, fully account for distraction.
  Psychophysiology 02/2009; 46(2):425-38.
• Article: Self-reported and P3 event-related potential evaluations of condoms: does what we say match how we feel?

  Sarah A Lust, Bruce D Bartholow
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  ABSTRACT: Research consistently reveals positive self-reported condom evaluations, yet such evaluations often do not predict condom use. Whereas positive self-reports likely reflect social norms regarding prevention of diseases and pregnancy, psychophysiological measures might better assess spontaneous condom evaluations. Here, participants completed a visual oddball task in which condoms and alcoholic beverages were infrequent targets among neutral, positive, and negative context images. Although self-reported condom evaluations were very positive, condom images presented in a negative context produced a smaller P3 than condom images presented in a neutral or positive context, suggesting that spontaneous condom evaluations were more negative than positive. The P3 elicited by alcohol images indicated positive evaluations. The findings underscore the multifaceted nature of evaluations and point to the utility of ERPs for assessing health-related attitudes.
  Psychophysiology 02/2009; 46(2):420-4.
• Article: Effects of intermodal attention on the auditory steady-state response and the event-related potential.

  Katja Saupe, Andreas Widmann, Alexandra Bendixen, Matthias M Müller, Erich Schröger
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  ABSTRACT: The aim of the present study was to simultaneously measure and compare intermodal attention effects in event-related brain potentials (ERPs) and auditory steady-state responses (ASSRs). For this purpose, 40-Hz amplitude modulated tones and a visual fixation cross were presented concurrently. By means of target detection tasks either on the sounds or on the fixation cross, participants' attention was directed to the respective modality. Attended sounds elicited a negative difference (Nd) in the ERP relative to unattended sounds. Nd was divided into an early and a late part as often observed for intramodal attention. Moreover, attention to the sounds led to a significant enhancement of the ASSR. This modulation of the ASSR by intermodal attention is demonstrated for the first time in the EEG. The present data suggest that ASSRs could provide a useful tool for the investigation of the neural dynamics of intermodal attentional processes.
  Psychophysiology 02/2009; 46(2):321-7.
• Article: Improving the performance of physiologic hot flash measures with support vector machines.

  Rebecca C Thurston, Karen A Matthews, Javier Hernandez, Fernando De La Torre
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  ABSTRACT: Hot flashes are experienced by over 70% of menopausal women. Criteria to classify hot flashes from physiologic signals show variable performance. The primary aim was to compare conventional criteria to Support Vector Machines (SVMs), an advanced machine learning method, to classify hot flashes from sternal skin conductance. Thirty women with > or =4 hot flashes/day underwent laboratory hot flash testing with skin conductance measurement. Hot flashes were quantified with conventional (> or =2 micromho, 30 s) and SVM methods. Conventional methods had poor sensitivity (sensitivity=0.41, specificity=1, positive predictive value (PPV)=0.94, negative predictive value (NPV)=0.85) in classifying hot flashes, with poorest performance among women with high body mass index or anxiety. SVM models showed improved performance (sensitivity=0.89, specificity=0.96, PPV=0.85, NPV=0.96). SVM may improve the performance of skin conductance measures of hot flashes.
  Psychophysiology 02/2009; 46(2):285-92.
• Article: Within-individual discrimination on the Concealed Information Test using dynamic mixture modeling.

  Izumi Matsuda, Akihisa Hirota, Tokihiro Ogawa, Noriyoshi Takasawa, Kazuo Shigemasu
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  ABSTRACT: Whether an examinee has information about a crime is determined by the Concealed Information Test based on autonomic differences between the crime-related item and other control items. Multivariate quantitative statistical methods have been proposed for this determination. However, these require specific databases of responses, which are problematic for field application. Alternative methods, using only an individual's data, are preferable, but traditionally such within-individual approaches have limitations because of small data sample size. The present study proposes a new within-individual judgment method, the hidden Markov discrimination method, in which time series-data are modeled with dynamic mixture distributions. This method was applied to experimental data and showed sufficient potential in discriminating guilty from innocent examinees in a mock theft experiment compared with performance of previous methods.
  Psychophysiology 02/2009; 46(2):439-49.