Anticipation of future interaction and the bystander effect

Previous research suggests that people are slower to offer help in an emergency when there are other witnesses than when there are not. This finding has come to be known as the bystander effect. In research that has demonstrated this effect, however, the other witnesses were invariably anonymous others who had no relationship with the subject and with whom the subject probably did not expect to interact again. The present research examined the hypothesis that the expectation of participating in subsequent face-to-face interaction with other bystanders would cause the bystander effect to be minimized. Female college students were led to believe either that they would have no personal contact with the other participants in an ostensible group discussion, or that the participants would be involved in a later face-to-face discussion session. Each subject then participated in what she believed to be an anonymous discussion via intercoms, involving either one person or five persons beside herself. During this period, an ostensible co-subject experienced a choking fit. Help was offered more quickly among subjects who expected future interaction than among those who did not. In the no future interaction condition, latencies to help were longer in six-member than in two-member groups, but the comparable difference, although in the same direction, was not reliable among subjects who expected interaction. Presence of male “co-subjects” in an exploratory condition failed to inhibit helping. Discussion centers on the broader implications of the findings.     

Gaze and emotional expression: The effects of message positivity-negativity and emotional intensity

The effects of emotional positivity-negativity and emotional intensity on actor's gaze were examined by simulating emotional situations to a camera. Female subjects were first asked to act out a neutral message as if they were speaking to a person to obtain a baseline for direct gaze. Subjects were then asked to perform a positive or a negative message to the camera. Half the subjects attempted to express the message with strong emotion; half expressed it with weak, ambivalent emotion. As expected, it was found that more direct gaze was maintained when expressing strong emotion. Whether the message was positive or negative did not affect gaze direction. The results were discussed in relation to the dimensions of nonverbal communication.     

A factor analytic and reliability study of the Devereux Child Behavior Rating Scale

The factor structure of the Devereux Child Behavior (DCB) Rating Scale was found to be different in the present study from those reported by the authors of the scale. Five of the 17 DCB factors were too unreliable to include in the present factor analysis. The findings of the present study were strikingly similar with other factor analytic studies of behavior rating scales in that only three main factors were found: Conduct Disorder, Personality Disorder, and Inadequacy-Immaturity.     

A simple stimulus cue for controlling disruptive classroom behavior

In two separate classrooms, a red light which had no specific consequences attached was used to reduce the talking-out and out-of-seat behavior of elementary school subjects. Following baseline phases, the light was introduced for a one-week period. An observer activated the light whenever the targeted behaviors occurred. Following a return to baseline, the light was reintroduced for a second one-week period. Results indicated that for both subjects a 95% or greater reduction in targeted behaviors occurred during the red-light phases. The results demonstrated the short-term effectiveness of a simple procedure which does not require specific back-up consequences for the reduction of disruptive behavior. The author concluded that studies using stimulus cues as part of reward or punishment procedures should employ a baseline procedure which controls for the effect of the stimulus cue without specific back-up consequences.This work was supported by Grant No. MH-18966 from the National Institute of Mental Health to Roberta Ray, Oregon Research Institute. The author is indebted to Roberta Ray, Oregon Research Institute, for her advice and support and to Paul Randall, Eugene Public Schools, for his assistance in conducting this research. Data reported in this article were collected as part of a study examining the effect of observer- and self-operated discriminative stimuli in the control of disruptive behavior. A complete copy of the report is available from the author.     

Polysemy and memory

The degree of ambiguity of words with multiple meanings was estimated by the semantic uncertainty (U) of a word as measured by word association and sentence generation tasks. Ambiguous words defined in this way were as well remembered in a recognition memory test as control words. When words were first presented in sentences that would determine their encoded sense, it was found that successive encodings of an ambiguous word converged more when the word appeared in its primary sense than when it appeared in its secondary sense. However, given convergent encodings, recognition was more likely if the word had first occurred in its secondary sense. An explanation in terms of semantic focus is offered and related to the general relationship between recognition and frequency.The research reported in this paper was supported by the Learning Research and Development Center, which is supported in part by the U.S. Office of Education.     

A simple turntable for vestibular stimulation of cats by acceleration through a fixed angle with description of a head restraint

An inexpensive turntable for producing uniform angular accelerations for use in vestibular research is described. The table provides semicircular canal stimulation for cats or smaller animals at moderate accelerations above 3 deg sec^?2. A head restraint suitable for use on the table and designed for chronically implanted cats is also described.     

The importance of being first: A tachistoscopic study of the contribution of each letter to the recognition of four-letter words

Three studies investigated the effect on the response time for voicing a four-letter word of delaying one of the letters or the entire word for intervals of up to 500 msec. Experiment I found delay of the first letter most detrimental, while delay of the second, third, or fourth letter facilitated performance. Experiment II confirmed these findings and indicated that delay of the entire word produced response times similar to delay of the first letter. Experiment III investigated the possibility that knowledge of the pronunciation of the first letter was the essential factor in facilitating performance when later letters were delayed. It was concluded that when pronunciation of the first letter was known, Ss were able to begin processing the word immediately.     

Decision making and the P300 component of the cortical evoked response

The amplitude of P300, and of other components of the evoked potentials, was examined during a task which required Ss to make a response appropriate to the conjoint properties of two rapidly successive visual patterns. In one set of conditions, the task was structured such that both stimuli were needed for the choice judgment. In another set of conditions, the task was changed from choice to simple RT by presenting the patterns in a predictable order. It was observed that P300 was enhanced during the choice RT conditions and that this enhancement was present only for the P300 following the stimulus permitting the choice and not the other, relevant but not decisive, stimulus appearing in close temporal proximity. An appreciable degree of independence between P300 and other components was indicated by the appearance of P300 under conditions in which other evoked potential components were entirely refractory. The data support an account for P300 in terms of poststimulus processes, such as decision making, and not in terms of preparatory adjustments.