Identification of temporal order within auditory sequences

Unpracticed Ss reported the order of sounds in sequences consisting of either three or four successive items repeated over and over without pause. With unrelated sounds each lasting 200 msec, correct reports of order were at chance level for oral responses and for card-ordering responses (each card bearing the name of one sound). The sequences with four unrelated items were studied in greater detail, and the threshold for identification was found to be 670 msec with oral responses and 300 msec with card-ordering responses. When two related sounds (tones) were used in four-item sequences, correct card-ordering was possible at 200 msec per item when the tones were temporally contiguous, but was not possible at this duration when the tones were separated by nonrelated sounds. Some special rules governing auditory sequence identification were suggested, and implications for theories of auditory perception discussed.     

A note on a simple procedure for redistributing a teacher's student contacts

A class of twelve third-grade students in a rural school of two grades per teacher was observed to determine the frequency of student-teacher contacts for each student. Requiring each child to go to a play area when he completed his work resulted in changing the distribution of these contacts so that the better students used fewer teacher contacts. In addition, the number of completed assignments of all students increased and data are presented which imply that the poorer students of the class received more of the teacher's available time than previously. The application of this procedure to special pupil populations would probably be very useful. A number of advantages and limitations of the procedure are described.     

Intermodality relations in localization in blind and sighted people

Developmental data were gathered on the relative importance of vision, audition, and proprioception in determining spatial direction in a conflict situation. Age trends did not support the hypothesis that information from different modalities becomes better differentiated with age. In a follow-up study, blind children of different ages were tested under auditory-proprioceptive conflict conditions. No age changes were found. The possibility of a visual involvement in auditory and proprioceptive localization is discussed.     

Further evaluation of a sensitive method for detecting experimental brain lesions.

Small, unilateral cortical lesions were placed in either medial-anterior, lateral-anterior, or posterior cortex of 20 male, Sprague-Dawley, albino rats. In addition, unilateral sham operations were performed on 8 rats from the same stock. All subjects had been trained prior to surgery with diametrically opposed visual habits mediated by opposite cerebral hemispheres. The opposing habits were, insofar as possible, evenly matched prior to surgery. After surgery, lesioned hemispheres, regardless of locus of lesion, were slower in acquiring the habit they mediated, than were unlesioned hemispheres. Further, unlesioned hemispheres dominated in test trials in which subjects chose one of the two cue doors with both eyes open. These findings confirm that the "interocularly conflicting discrimination" baseline detects a role of extrastriate cortex in mediation of pattern discrimination habits. They further indicated that losses occur without regard to the various locations of lesion employed.     

Temporal discrimination of recycled tonal sequences: Pattern matching and naming of order by untrained listeners

Sets of recycled sequences of four successive tones were presented in all six possible orders to untrained listeners. For pitches within the musical range, recognition (as measured by matching of any unknown order with an array of permuted orders of the same tones) could be accomplished as readily for tonal durations and frequency separations outside the limits employed for melodic construction as inside these limits. Identifying or naming of relative pitches of successive tones was considerably more difficult than matching for these tonal sequences, and appeared to follow different rules based upon duration and upon frequency separation. Use of frequencies above the pitch limits for music (4,500 Hz and above) resulted in poor performance both for matching and naming of order. Introduction of short silent intervals between items was without effect for both tasks. Naming of order and pattern recognition appear to reflect different basic processes, in agreement with earlier formulations based on experiments with phonemic sequences of speech and sequences of unrelated sounds (hisses, tones, buzzes). Special characteristics of tonal sequences are discussed, and some speculations concerning music are offered.     

THE EFFECT OF MODELLING ON DRINKING RATE

Three male college seniors were asked to drink beer at their normal rate in a simulated tavern setting. Each was paired with a confederate, also a male college senior, in an ABACA single subject design. In the baseline conditions, the confederate matched the drinking rate of the subject. Baseline and all subsequent conditions were continued in 1-hr sessions until a stable drinking rate was achieved. In Condition B, the confederate drank either one third more or one third less than the subject's baseline rate. In Condition C, the direction was reversed. All three subjects closely matched the confederate's drinking rate, whether high or low. All subjects reported they were unaware of the true purpose of the study.     

Dual semantic encoding of homographs and homophones embedded in context

Dual encoding of homographs and homophones was inferred from the intrusion of their alternative meanings across trials in two experiments using a modified Brown-Peterson paradigm. In Experiment 1 subjects heard a word triad and then engaged in a 10.5-sec distractor task. Written recall was then demanded. On context trials a homophone with alternative meanings belonging to two distinct categories was embedded in a triad biasing one meaning, e.g., helpless,/wik/, fragile. On the next trial, words from the category of the other meaning were presented, e.g., year, month, decade. A significant number of intrusions of the alternative coding of the homophone, e.g., WEEK, across the category boundary were observed. Experiment 2 employed visual presentation of embedded homographs, e.g., plunged, jumped, DOVE, and oral recall but was logically similar to Experiment 1. Intrusions of the alternative codings of homographs across category boundaries, e.g., pigeon, sparrow,/d Λ v/, were again noted.