This report refers to a body of investigations directed toward the examination of autonomic nervous system responses to motion sickness. Heart rate, respiration rate, finger pulse volume, and basal skin resistance were measured on 127 men and women before, during, and after exposure to a nauseogenic rotating chair test. Significant changes in all autonomic responses were observed across the tests (p<.05). Significant differences in autonomic responses among groups divided according to motion sickness susceptibility were also observed (p<.05). Results suggest that the examination of autonomic responses as an objective indicator of motion sickness malaise is warranted and may contribute to the overall understanding of the syndrome.

3 studies are reported investigating human preference for immediate vs. variably delayed shock with and without a warning signal. The information-preparation theoretical statements of Berlyne and Perkins were used for predicting that immediate shock would be preferred under 100% shock with no warning signal for the delayed condition and that this preference would be prevented or reversed when shock occurred only 25% of the time and a warning signal preceded delayed shock. Study 1 (N = 20) used an unstructured free-choice task with 100% shock and no warning signal; Study 2 (N = 20) replicated the first study, but used a structured forced-choice task. The final study (N = 40) presented shock on only 25% of the trials and a 4-sec. warning signal preceded delayed shock for an experimental but not control group. The predictions were confirmed.

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Human Ss preferred warned shock to unwarned shock when the warning signal concained 2 b~ts of information (25% shock) but not when i t was redundant, i.e., 0 bits (100% shock). Rated strength of preference was also related to the information conra~ned in the warning.The research reported here deals with the important role of environmental stimuli or warning signals which make experimental events more predictable.A simple but central question guided our research: Do individuals or organisms prefer to "know" when an aversive event is going to occur? Stated differently: Do organisms prefer information about an aversive event that is uncertain, "inescapable," and unavoidable?Theoretical guidelines for chis investigation were provided by Perkins (1955) and Berlyne (1960). Both theorists depart from traditional reinforcement theory by emphasizing that information relative to either attractive or unattractive outcomes is reinforcing and that scimuli providing this information will be sought out. For example, Perkins staces chat warning signals (conditioned stimuli) make the environment more predictable and allow the organism to make responses which prepare it to deal more effectively with the environment, i.e., to maximize the attractiveness of stimulus situations or to minimize their aversiveness. Berlyne, on the other hand, emphasizes uncertainty reduction. For Berlyne, uncertainty or unpredictability of an event is aversive and any event which reduces it is considered reinforcing. Therefore, information provided by conditioned stimuli or warning signals would be preferred since it enhances the predictability of experimental events and outcomes.While infra-human studies have provided support for che information-preparation interprecacion (Lockard, 1963; Perkins, Levis, & Seyman, 1963), relatively little research has been reported with humans. The present research provides data at the human level and also actempts to tesc a differential prediction between the theoretical fornulacions of Perkins and Berlyne. By using measures of uncertainty derived from formal information theory it is possible to structure an experimental situation such that uncertainty of an event can be quantified and varied without altering the condicions leading to preparation For instance, the following research design used a two-choice unavoidable shock situation where variably delayed shock followed either response (mean shock delay = 30 sec.). However, for one of the choices a warning signal provided information (preceded shock by 4 sec.) relative to shock onset. Two groups were run under che above condicions. Group I received shock on every trial for either

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Modulation by two temporal frequencies differentiates visual processing at the fundamentals (lFs), second harmonics (2Fs), and second-order intermodulation components (IMCs), the latter created neurally as the sum or difference of the two modulation frequencies. Steady-state VEPs were recorded while stereo-normal adults viewed luminance or grating stimuli modulated by up to three temporal frequencies under dichoptic, monocular, or ordinary (binocular) viewing conditions arranged using liquid crystal light shutters. In Experiment 1, modulation of luminance by a single temporal frequency produced strong IF and 2F VEP components, but modulation of gratings produced only 2Fs. Modulation by two temporal frequencies resulted in IMCs, often in the absence of evoked activity in the EEG at the lFs. IMCs were generally larger during pattern as compared to luminance modulation. Amplitudes of lFs and IMCs were smaller, but 2Fs were larger, during dichoptic as compared to ordinary viewing. Although the 2F to a single modulation presented to one eye was not reduced when a second frequency was added to the opposite eye, monocular IMCs were diminished when a frequency was added to the opposite eye. We conclude that 2Fs and IMCs are associated with different neural substrates. Results are consistent with a two pathway model with one pathway having a nonlinear filter prior to binocular combination, the other pathway having a nonlinearity following binocular linear summation. Implications of these data for binocular function are discussed.