Slow alpha in the EEG power spectrum as an indicator for conceptual arousal]

Based on previous findings (B?sel et al., 1990) it was assumed that in concept learning tasks generating on hypotheses on a concept which has to be developed is accompanied by increases of the Alpha 1 power (7.5-10 Hz) in the spontaneous EEG activity. In this study 16 subjects performed five problem solving tasks with similar processing requirements. EEG data were analyzed by means of post hoc comparisons of subjects differing in performance quality. Additionally, four control tasks were employed in which, based on previous studies, variations in the Theta frequency range were expected. An effect in the Alpha 1 frequency band was observed in tasks requiring reconstructive recall or testing the usefulness of an mathematical algorithm. The creation of a rank order or mental map is accompanied by power increases in the lower portions of the Alpha 1 frequency band (7.5-8.5 Hz). Moreover a high amount of controlled variance (eta2 up to 34%) was obtained for this effect. Increases in EEG Theta power, which presumably indicate subjects' component analysis, were found before the subjects recognized parts of geometric figures or before relevant features in the "buddhist monk problem" were discriminated. The dynamics of EEG power over time is in examples of frequency/time plots in a figure, illustrated.     

The squeal as an indicator of aggression in mice

Fighting behavior of paired male mice was observed while automatic recording equipment counted the squeals. A strong positive relationship was found between the squeals and other measures of fighting. The results are discussed in terms of the validity of squeals as a measure of aggression and the usefulness of the squeal measure and the advantages it provides, i.e., the possibility of continuous monitoring of fighting behavior, elimination of O effects, less handling of Ss, and use of a “home cage” type of environment.     

The P600 as an indicator of syntactic ambiguity

In a study using event-related brain potentials, we show that the current characterization of the P600 component as an indicator of revision processes (reanalysis and repair) in sentence comprehension must be extended to include the recognition of syntactic ambiguity. By comparing the processing of ambiguous and unambiguous sentence constituents in German, we show that the P600 is elicited when our language processing system has syntactic alternatives at a certain item given in the input string. That the P600 is sensitive to syntactic ambiguity adds crucial evidence to current debates in psycholinguistic modelling, as the results clearly favour parallel models of syntactic processing which assume that ambiguity is recognized and costly.     

The pupillary response as an indicator of arousal and cognition

Psychological research on the pupillary response since 1960 has focused on an arousal interpretation and a cognitive interpretation. Experiment 1 was an attempt to manipulate some arousal factors while controlling the cognitive demands of the task. Pupil size was cinematographically recorded while subjects who had different degrees of reported fear of snakes listened to passages describing imagined interactions with a snake in different proximities. There was also a set of control passages that made no mention of snakes but were otherwise semantically and syntactically identical to the aversive passages. The pupillary response showed no influence of the arousal manipulations, but rating and behavioral data indicated that the arousal variables had been effective. The cognitive demands of the task were clearly indicated by the pupillary response. In Experiment 2 two types of tasks were used: one that employed both arousal (incentive) and cognitive factors and another that had an arousal manipulation (threat of shock) but no explicit cognitive demands. The pupil response was recorded as well as heart rate, skin conductance, and EMG. The pupillary response showed an effect of the arousal manipulations only when cognitive demands were minimal. The results of both experiments are consistent with the view that cognitive demands take priority over arousal factors in affecting the pupillary response. Heart rate did show arousal effects that were not preempted by cognitive demands.     

The anticipatory potential (contingent negative variation) as an indicator of neuronal information processing in relation to changes in slow potentials in the EEG

The aim of this study was to investigate the interaction between spontaneous Slow Potential Shifts (SPSs) and the probability effect on CNV amplitudes. Fifteen right-handed volunteers participated in this experiment. The presentation of the stimuli was triggered by spontaneous SPSs (duration: 2 seconds, mean-amplitude: 10 microV) in the EEG signal at Cz. Thus, two different S1s (S1a: 1500 Hz, S1b: 2000 Hz) were presented in a random order with a fixed probability of occurrence of 0.8 for S1a and 0.2 for S1b. Each S1 was followed by a light stimulus (S2) with a constant ISI of 4 seconds. According to the cue, the subjects had to push the left (S1a) or the right (S1b) response button as fast as possible with their right index finger. The order of the 4 experimental conditions (stimulus presentation triggered by negative or positive shifts and recording of negative or positive shifts without any stimuli) in which each subject participated was balanced across subjects. Several significant effects could be found by means of a two-way ANOVA for repeated measures (condition x recording site): Negative shifts were accompanied by smaller CNVs as well as PINVs (resolution deficits) at all recording sites; the probability effect was found to be significant in the positive shift condition at F3, F4, and Cz, but not in the negative shift condition except at Cz for the E-wave. CNVs triggered by negative shifts only showed a significant correlation (-.55) with reaction time. These results together favor a two-component model suggesting that SPSs, spontaneous and evoked, are largely generated by glia depolarization, which is evoked by but outlasts neuronal activity.     

The mismatch negativity to frequency deviants during the transition from wakefulness to sleep.

This study examines the changes in the Mismatch Negativity during the transition from a waking, conscious state to one of sleep and unconsciousness. Auditory event-related potentials were recorded from eight participants during the sleep onset period. A 1,000 Hz-standard stimulus was presented every 600 ms. At random, on 20% of the trials, the standard was changed to either a large 2,000-Hz or a small 1,100-Hz deviant. During wakefulness, the large deviant elicited a larger, long-lasting MMN than the small deviant. Following the large deviant during relaxed wakefulness and Stage 2 sleep, the MMN continued to be elicited although it was reduced in amplitude. No significant MMN was recorded for either deviant in Stages 1 and slow wave sleep. The loss of consciousness therefore appears to have a marked effect on the MMN.     

Addiction as an indicator of vulnerability: The case of indoor tanning

Research concerning the marketing of potentially harmful products to vulnerable consumer segments reveals difficulties in identifying vulnerable consumers. Businesses must be able to identify such segments if they are to avoid regulation and consumer activism. Whether a measure of nonsubstance addiction is an appropriate indicator of vulnerability is examined here in the context of indoor tanning. Three studies of young adult tanners indicate that (a) a modified alcohol addiction scale, the CAGE index, can be used to measure other addictions; (b) addicted indoor tanners have high motivation to meet social appearance norms and to experience the feeling of tanning, which may make them susceptible to marketing cues for indoor tanning; and (3) addicted and nonaddicted indoor tanners are similar in their knowledge of the dangers of indoor tanning, thus supporting the assertion that addicted tanners' decisions to tan indoors are likely more influenced by addiction than by informed decision making.     

Hemispheric lateralization of the EEG during wakefulness and REM sleep in young healthy adults

EEG recordings confirm hemispheric lateralization of brain activity during cognitive tasks. The aim of the present study was to investigate spontaneous EEG lateralization under two conditions, waking and REM sleep. Bilateral monopolar EEG was recorded in eight participants using a 12-electrode montage, before the night (5 min eyes closed) and during REM sleep. Spectral analysis (0.75-19.75 Hz) revealed left prefrontal lateralization on total spectrum amplitude power and right occipital lateralization in Delta activity during waking. In contrast, during REM sleep, right frontal lateralization in Theta and Beta activities and right lateralization in occipital Delta activity was observed. These results suggest that spontaneous EEG activities generated during waking and REM sleep are supported in part by a common thalamo-cortical neural network (right occipital Delta dominance) while additional, possibly neuro-cognitive factors modulate waking left prefrontal dominance and REM sleep right frontal dominance.     

Vocal affect expression as an indicator of affective response

This research is designed to validate the measurement of vocal affect expression as an accurate indicator of affective responses. Subjects who support legalized abortion read aloud either proattitudinal or counterattitudinal statements. Their recorded voices were digitized, standardized against their own baseline vocal parameters, and analyzed for differences in mean and range of fundamental frequency between the pro-attitudinal and counterattitudinal conditions. Subjects with strong initial attitudes exhibited the expected pattern of negative affect while reading counterattitudinal material. However, subjects with initial attitudes moderate in strength exhibited an unexpected pattern of negative affect when reading pro-attitudinal information. Written measures of the affective and evaluative components of attitudes toward: abortion and; a measure of mood were employed to validate the voice measure.     

Skin conductance as an indicator of anticipated concealed knowledge

The present study investigated the effects of anticipation on skin conductance while participants were answering a set of questions which included one of concealed knowledge. Two experiments were conducted. In Exp. 1, 26 participants completed one experimental session. Each participant was asked to choose one two-digit number from 10 to 99 and was presented 19 other randomly generated two-digit numbers. The list of numbers was then presented to the participant on a computer screen, with a 60-sec. interval occurring every two questions. The participant-selected number was defined as the target question which was randomly placed within the 4th to 17th item of 20 questions stated as follows: "Is your selected number?" The participant was asked to answer "No" to all questions. The skin-conductance response to each question was measured. In Exp. 2, the experimental procedure was the same as that in Exp. 1 except each participant first answered 10 nontarget questions, then answered a target question with the participant's selected number, and then answered another 10 nontarget questions. There were a total of 21 questions. Analysis indicated participants in both experiments generated the highest mean skin conductance while answering the target questions, followed by lower amplitudes to questions prior to and after the target question. The skin-conductance response pattern can be used to identify the psychological process of anticipation of concealed information.     

Politicians' estimated height as an indicator of their popularity

Previous research has found that an electoral candidates' eight is correlated with their image. Many studies have found that height is a great asset for a candidate as height correlates with electoral outcome. In this research the previously obtained results were partially confirmed—in the first study the supporters of a given candidate estimated him as taller than his opponents (confirmed by six out of 10 candidates). The second study, conducted during the presidential elections in Poland, showed that electorate‐perceived height of candidates for the Presidency changed after the first phase of elections (confirmed by three from six main candidates). These changes in electoral‐perceived height depended more upon their electoral support than attitudes toward them. Copyright © 2009 John Wiley & Sons, Ltd.     

The stroop color-word interference test as an indicator of ADHD in poor readers

The performance on the Stroop Color-Word Interference Test of 36 boys with Attention Deficit Hyperactivity Disorder (ADHD) was compared with performances of a matched control sample. The control group outperformed their counterparts on the control and interference conditions of the Stroop test, suggesting ADHD-specific executive and reading deficits. When individuals with both ADHD and reading disorders were excluded from the analysis, the authors found a significant difference between the ADHD group and the control group on the color-word test, indicating that poor reading skills may produce false negatives on the Stroop test. However, fast and slow readers with ADHD did not perform differently from each other on the color-word test. The authors postulated the existence of two different causes of reading problems: phonological deficits and attentional deficits.