Decreased helpfulness with increased group size through lessening the effects of the needy individual's dependency1

The present experiment attempted to integrate the research on helpfulness in which subjects work for someone else in an artificial laboratory setting (Berkowitz & Daniels, 1963; Berkowitz, 1972) with the bystander-intervention-in-emergencies studies often carried out under more realistic conditions (e.g., Latané & Darley, 1970; Schwartz & Clausen, 1970; Clark & Word, 1972). Fifty-six university women in a 2 × 2 factorial design were led to think they were working for a same-sex peer who could win a cash prize, although there was “nothing in it for them.” Half were told that the other's chance of getting the prize was greatly dependent upon their effort while the remaining participants were informed that the other did not need their-work very much. Moreover, half of the subjects thought they were the only ones working for the other whereas the remaining people believed there were two other co-workers and that the output from all three would be averaged. It was expected that the participants would feel the greatest personal responsibility to help the other and would work hardest for her when she was greatly dependent upon their productivity and they were the only worker, while the subjects would feel the lowest level of personal responsibility for their peer and would be least helpful to her when she was not particularly dependent upon them and there were two other co-workers. The findings are generally in accord with these expectations.     

The relationship between frontalis muscle activity and self-reports of headache pain

The relationship between levels of frontalis muscle activity and self-reports of pain was evaluated in two studies. In Study I frontalis muscle activity and self-reports of pain collected during biofeedback treatment of muscular contraction headache clients were correlated. In Study II frontalis EMG activity was increased and decreased using biofeedback techniques while concurrent reports of headache pain were recorded. The results of Study I indicated a significant relationship between EMG activity and reported headache pain for only two of the five subjects studied. The biofeedback procedures in Study II were associated with reliable increases and decreases in EMG activity. Concordance between EMG and pain reports occurred only during the EMG increase condition. Overall correlations were significant for one of the 2 subjects. The results suggest that EMG activity may not be sufficient to account for pain reports in all chronic headache clients, and variables other than EMG activity may be influencing reports of pain in some patients.     

Visual processing of multielement arrays and selective backward masking

In the first of two selective masking experiments, 7-letter rows were followed at several ISIs by a mask or no-mask and a bar-marker partial report cue. The results suggest that the arrays were processed ends-first and then, in general, from both ends towards the middle. In the second experiment, bar-marker partial report cues were presented at the onset or offset of 6-letter/1-digit or 7-letter rows. The subjects could not anticipate the category of the to-be-reported item with the alphanumeric displays. With a delayed cue, selective masking was obtained with both mixed category and pure letter arrays, but with simultaneous cuing, masking was always distributed across all serial positions. The results suggest that the subjects: (a) abstracted some information about category from the mixed arrays during an initial parallel stage of processing, (b) selectively attended to mainly the cued item with simultaneous probes with homeogeneous and mixed category displays, and (c) employed an ends-first processing strategy with both types of arrays when the bar-marker partial report cue was delayed.     

Saccade latency and warning signals: Effects of auditory and visual stimulus onset and offset

Previous studies have found that a nonspecific visual event occurring at the fovea 50–150 msec after the onset of a peripheral target delayed the initiation of the saccade to that target. The present studies replicated and extended this finding by studying the effects of both visual and auditory warning signals, by examining the effects of onset and offset warning on manual response latency, and by investigating the effects of presenting the warning events in the periphery of the visual field. The results indicated that the interfering effects occur with visual but not auditory stimuli, with saccades but not motor responses, and when the visual warning event occurs either foveally or in the subject’s periphery. Implications for the processes involved are discussed.     

Attentional biases and the right-ear effect in dichotic listening

Most dichotic listening experiments permit subjects to deploy attention in any way they choose. We argue that this adds uncontrolled variance to the observed right-ear advantage. In the first experiment, more robust laterality effects were obtained in an identification task with focused than with divided attention. Such differences were not found in the second experiment, when a detection procedure was used. Virtually all the laterality effect observed in the second study could be attributed to subjects who were biased attenders, in the sense that they exhibited more intrusions from the right ear to the left than vice versa. However, rather than indicating that laterality effects are simply attentional bias, this effect can be attributed to an asymmetry of perceptual discrimination.