Schedule control of the vocal behavior of Cebus monkeys

The vocal behavior of three Cebus monkeys was maintained by fixed-ratio schedules of response dependent reinforcement at values between fixed-ratio 1 and fixed-ratio 15. In one monkey that was exposed to variable-interval, fixed-interval, and conjunctive fixed-ratio fixed-interval schedules of reinforcement, vocal responding occurred at a low rate, but schedule-appropriate patterns were maintained. The rates and patterns of responding engendered indicated that the vocal operant can be brought under schedule control in the monkey by the use of response-dependent reinforcement.     

The capacity for rapid shifts in level of mental concentration

This investigation continues the exploration of a largely neglected topic in the field of attention, levels of mental concentration, by ascertaining under optimal conditions the capacity for shifting quickly from one level to another. Previous research in our laboratory had applied a set of five post-hypnotically cued levels of concentration or “cognitive arousal”, covering a very wide range, to a variety of perceptual and cognitive tasks. In the present study two highly trained undergraduate hypnotic subjects, one male and one female, were given progressively shorter time durations in which to respond to the post-hypnotic cues before viewing tachisto-scopically flashed consonants under cue influence. The results indicate a striking capacity to shift degrees of cognitive arousal very rapidly to one extreme or the other, on the order of 100 ms or less.     

Pause measures during reading and recall in serial list learning

An investigation is reported into pausing and grouping during the serial learning of letter strings, when presented randomly by length and when presented in ascending order. Mean pause times for the reading and recall of longer lists were significantly greater than for lists of shorter span due to extended pausing at specific list positions. In general, reading rhythms were duplicated during recall. Subjects were highly consistent in maintaining their level of pause duration across lists and responded to additions in list length by increasing their number of groups, not by increasing group size. Triadic sequences were the most popular form of spontaneous organization. Pausing measures are discussed as indices of organizational strategies.     

A device for the easy administration of volatile anesthetics to rats undergoing stereotaxic surgery

Conventional procedures do not provide a practical method for the administration of volatile anesthetics such as halothane to rats while they are undergoing stereotaxic surgery. This paper describes a device which meets this need and which is easy and inexpensive to construct. A two-piece cylinder cut from the mouth of a polyethylene bottle forms a closed system around the muzzle of a rat and does not interfere with the stereotaxic apparatus or with the operation itself. The cylinder is attached to any standard device for the dispension of volatile anesthetics. The immediate advantage is that behavioral assesaments can be made relatively soon after surgery.     

Error patterns in a chord keyboard response task

Errors in a serial choice-reaction time experiment employing two-finger chord responses to alphabetic stimuli are shown to be distributed in a significantly non-random fashion. Two factors are postulated which are relevant to prediction of the error response. These are the presence or absence of a common finger, and the difference in finger separation, between the actual and the required response. It is suggested that the chord response is coded in terms of a pattern (the distance between the two response components). Responses which mirror the correct response about the centre of the hand are also shown to be significantly more frequent.     

A model for career development through curriculum

This article describes a practical model for a systematic, sequential approach to career development in the K-12 curriculum. The model builds on career development principles and vocational development tasks; it is self-concept oriented and uses a variety of methods and media in its implementation. Several strategies for facilitating career development are suggested for each level.     

Attention in bisensory simultaneous short-term memory

Subjects were presented with simultaneously visual and auditory material. They were instructed to attend to only one modality but were required to recall materials from both modalities, one before the other. Results supported a previous suggestion that visual recall is minimum under conditions of simultaneous presentation. That is, in situations where S is allowed to divide his attention between both inputs, visual recall was no greater than when his attention was directed away from visual input and to auditory input. It was noted that this difference in recall between the two modalities was limited to verbal material, as other data indicate the opposite effect for nonverbal material.     

Training the absolute identification of pitch

Two methods for training the absolute judgment of pitch, reference training and series training, were studied. Reference training concentrated during training on the identification of three reference tones in a set of nine pure tones, while series training gave equal weight during training to the identification of all nine tones. Results of pre- and posttraining tests, scored for the number of correct judgments, showed that reference training was more effective than series training for listeners with musical experience. In addition, discriminability (d′) scaling of pre- and posttest performance indicated that reference training was particularly effective for training listeners with musical experience when the nine tones of a set were grouped into three pitch classes—high, medium, and low pitch. Listeners without musical experience benefited from both training methods, but their overall improvement was less than that for musical listeners.