Changes in the EEG frequency spectrum in various phases of mental stress

To obtain evidence about the relationship between spontaneous EEG activity and mental activity, an experiment was designed and executed with EEG recordings during a concept-learning task. We varied task performance (self-paced vs. machine-paced) and distinguished different stages of information processing during task performance. Using factor analysis calculated on all spectral coefficients, we found two orthogonal variables in the clinical alpha band. Alpha 2 power (10.5-12 Hz) seems to reflect the overall processing demands imposed on the individuals. Furthermore, there are different EEG frequency patterns during perceptual-central- compared with response-related processing as well as during processing of positive vs. negative feedback. The results suggest using (1) conservative procedures in hypothesis testing and (2) procedures to reduce between subject variability (a posteriori defined frequency variables, relative power values, scaling of reaction values) in further studies relating EEG activity to mental activity during task performance.     

Differentiation of existential guilt and compassion in relation to responsibility induction: a film experiment

Feelings of existential guilt are assumed to depend on the perception of a causal relationship between one's own behavior or (privileged) situation and the disadvantages of others. By contrast, pity should not depend on such perceptions. This hypothesis, which has been supported so far only by correlational studies, was tested experimentally. Eighty students were shown a film about a developing country. The film was provided with four different comments, each representing one experimental condition (between-subjects design). Experimental factors were "amount of misery of the people shown" and "subject's responsibility for these peoples' conditions of life". As expected, subjects in the condition "misery and responsibility" reported higher feelings of guilt, though no more pity than subjects in the remaining three treatment conditions (experiment 1, n = 40). This mean difference, however, was statistically significant for men only. Contrary to our theoretical expectations--and to finding from other experiments on vicarious reparation--the induction of guilt had no effect on willingness to help a third party (experiment 2, n = 40). Possible reasons for this unexpected finding are suggested.