A method for the precise switching of speech

A simple procedure by which a speech signal may be switched on or off (or from one ear to the other) at a precise instant of time is described. The speech sample is first recorded on a magnetic tape loop. A reference pulse is then recorded preceding the speech signal. This reference pulse triggers an adjustable time delay which in tum operates an electronic switch at an appropriate time.     

A device for presenting targets and recording positioning responses in one dimension

Apparatus for recording manual target pointing localizations is described. The device, utilizing a position transducer and digital voltmeter, is capable of determining the position of either manual limb when localizing visual and/or auditory targets. The pointing localizations involve naturalistic limb movements made in a relatively unrestricted manner. The apparatus has the advantages of rapid accurate measurement, reliability, ease of reading, and the potential for automatic recording. When used for research involving adaptation to sensory rearrangement, there is the further advantage that the dependent measures are obtained in the same context as during exposure to the rearrangement.     

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.     

The psychological refractory period and vertex evoked potentials

The averaged sensory evoked potential (EP) was recorded from the scalp (vertex to mastoid) in a psychological refractory period experiment in which 12 young adults participated. Reaction times (RTs) were measured to either both or only the second of pairs of stimuli, in different trial blocks, with inter-stimulus intervals (ISIs) of 100, 200, 300 and 400 msec occurring in random sequence. EPs were recorded at each ISI. No latency changes could be found in the prominent non-specific components (P1-N1-P2) of the EP to stimulus 2 even at ISIs where the RT was substantially delayed. Thus the notions that the RT2 delay is due to occupation of a single channel central processor by S1 and that non-specific EP components reflect the time course of information processing in underlying neural tissue, do not lend each other mutual support. Furthermore, as profound amplitude refractoriness in components P1-N1 and N1-P2 persisted at ISIs where RT was as fast or faster than simple RT, there appears to be a dissociation between “psychological refractoriness” and “physiological refractoriness”. The implications of these results are discussed.     

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.     

A comparison of leverpress and head-poke discriminated Sidman avoidance

A discriminated Sidman avoidance procedure used by Forgione (1970) was replicated using a head-poke response instead of a leverpress as the avoidance operant. The resultant data were described in terms of the five dependent measures reported by Forgione. Head-poke avoidance was found to be more efficient than its leverpress counterpart and compared very favorably with the lever-disabling (or shock-timer-on) procedure used by Forgione to break up inefficient leverpress behavior patterns.     

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.