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B Rakerd

Publications and source records attributed to B Rakerd.

27 records · Page 2Linked to original sources
PubMed1985

A microcomputer-based system for recording and analyzing behavioral data regarding the sexual activity of male rodents.

A microcomputer (TRS-80 Model 4P) based system has been developed to aid in the collection and analysis of behavioral data regarding sexual activity in male rodents. Its capabilities include the recording of events, the online calculation of frequency and latency measures, the monitoring of temporal intervals as demanded by experimental protocols, and the prompting of experimenter activities at prescribed times.

Animals↗
PubMed1985

Linguistic and acoustic correlates of the perceptual structure found in an individual differences scaling study of vowels.

Subjects judged the similarities among a set of American English vowels (See Text) presented in isolation or in a/dVd/ consonantal frame. Individual differences scaling was employed to analyze these similarities data for each of the conditions separately and for the two conditions combined. In all cases, perceptual dimensions corresponding to the advancement, height, and tenseness vowel features were recovered. Given the determinacy of individual differences scaling, this finding is taken to provide strong evidence for the perceptual significance of those features. The perceptual dimensions are considered in relation to various acoustic parameters of the stimuli employed in this study. They are also considered in relation to perceptual dimensions that have been observed in other vowel scaling studies.

Humans↗
PubMed1985

Localization of sound in rooms, II: The effects of a single reflecting surface.

Auditory localization was studied in a room bounded by a single acoustically reflective surface. The position of that surface was varied so as to stimulate a floor, a ceiling, and left and right side walls. The surface was eliminated in one condition so that we could examine localization in free field for purposes of comparison. Using a source identification method we assessed the influences of these various room configurations on the localization of both slow-onset and impulsive sine tones of low frequency (500 Hz). We also measured the steady-state interaural-time-difference (ITD) and interaural-intensity-difference (IID) cues available to subjects in the different room configurations and compared these data with the perceptual judgments. Our results indicate the following: (1) A sound must include transients if the precedence effect is to operate as an aid to its localization in rooms. (2) Even if transients are present the precedence effect does not eliminate all influences of room reflections. (3) Due to the interference of reflections large interaural intensity differences may occur in a room and these have a considerable influence on localization; this is true even at low frequencies for which IID cues do not exist in a free field. (4) Listeners appear to have certain expectations about the reliability and plausibility of various directional cues and perceptually weight the cues accordingly; we suggest that this may explain, in part, the large variation in time-intensity trading ratios reported in the literature and also the differing reports regarding the importance of onsets for localization. (5) In this study we find that onset cues are of some importance to localization even in free field.

Acoustic Stimulation↗
PubMed1984

Monitoring for vowels in isolation and in a consonantal context.

The identifiability of isolated vowels (/V/) was compared to that of vowels in consonantal context (/pVp/) when subjects performed a monitoring task. On successive blocks of trials in a test series, the subjects listened for instances of one or another of nine monophthongal vowels (Formula: see text) and identified each test item as being an instance or not. On average, resulting false alarm errors occurred significantly less often in the /pVp/ condition, consistent with the previous finding that vowel perception may be aided by consonantal context. This beneficial effect of context was found to be restricted to the class of open vowels, however, with perception of the close vowels being somewhat hindered by context. The error data for misses also showed an interaction between context and vowel height. Various accounts of the interaction are considered.

Attention↗
PubMed1982

Induction of hindlimb stepping movements in rats spinally transected as adults or as neonates.

Rats were spinally transected as adults or as neonates. When their hindlimbs were held off the ground and tail pinch was applied, both groups of animals exhibited a strong tendency to step with alternating limbs. The most striking difference between the groups was in the rate of stepping, the neonatal spinals being significantly faster than the adult spinals. To our knowledge, this is the first evidence that adult-transected rats retain a degree of locomotion-related coordination.

Aging↗