Defensive burying of aversive fluids in rats: The possible role of odor

Defensive burying of flavored fluids paired with lithium chloride injections was examined. Rats showed little inclination to bury conditioned saccharin or salt solutions (Experiments 1 and 2). However, they buried tabasco sauce or dilute milk solutions readily (Experiment 3). It was hypothesized that the amount of olfactory stimulation provided by a solution may determine whether a rat engages in burying. This hypothesis received support in a final experiment which demonstrated that rats readily buried an arbitrarily selected odorous solution which was previously paired with lithium chloride. Thus the present experiments begin the process of identifying the circumstances under which burying does and does not occur.     

Defensive burying of aversive fluids in rats: The effects of peripheral anosmia

Three experiments were conducted in order to determine the role of olfactory stimulation in defensive burying of aversive fluids in rats. The results revealed that zinc sulfate-induced anosmia eliminated burying of fluids paired with lithium chloride as well as an inherently aversive solution. This occurred despite the fact that the rats avoided consuming them. These data indicate that defensive burying of aversive fluids is governed by olfactory stimuli and confirms an earlier report, which indicted that burying does not occur in response to aversive gustatory stimuli.     

APDA: A discontiguous S-R automated primate discrimination apparatus

The present paper describes a discontiguous S-R automated primate discrimination apparatus (APDA) designed to eliminate the stimulus sampling biases associated with previous manual and automated testing procedures and at the same time to provide greater specification of the S's intratrial discrimination behavior. Data from two simultaneous color discrimination problems are summarized as an evaluation of the current design.     

Evaluation of factor analytic research procedures by means of simulated correlation matrices

In order to study the effectiveness of factor analytic methods, a procedure was developed for computing simulated correlation matrices which are more similar to real data correlation matrices than are those matrices computed from the factor analysis structural model. In the present investigation, three methods of factor extraction were studied as applied to 54 simulated correlation matrices which varied in proportion of variance derived from a major factor domain, number of factors in the major domain, and closeness of the simulation procedure to the factor analysis structural model. While the factor extraction methods differed little from one another in quality of results for matrices more dissimilar to the factor analytic model, major differences in quality of results were associated with fewer factors in the major domain, higher proportion of variance from the major domain, and closeness of the simulation procedure to the factor analysis structural model.The research was jointly supported by the University of Illinois and the office of Naval Research under contracts Nonr 1834(39) and N00014-67-A-0305-0003.     

Response time to the second of two signals following varied vs constant intersignal intervals

The Ss made choice responses under three experimental conditions: (1) a variable interval between the warning signal and the signal to respond, (2) a constant interval between the warning signal and the signal to respond, and (3) omission of the warning signal. With variable intersignal intervals (lSI), response time (RT) was inversely related to lSI at least when the latter was in the 10 to 225 msec range. When lSI was constant its duration had no perceptible effect on RT. RT tended to be shorter with constant lSI. independent of its duration, than when the warning signal was omitted altogether.     

Effects of interpolating a secondary task during the intertrial interval of a concept identification problem

Several tasks were interpolated during the intertrial interval (ITI) of a concept identification (CI) task. In Experiment I, 234 subjects were required to count backwards by threes, emit a sibilant, or to refrain from thinking after all responses, after correct responses, or after errors. Counting backwards interfered with performance, but only if it occurred after errors. Stimulus and feedback information was either withheld, as in Experiment I, or made available during the ITI in Experiment II. Results of the data from 280 subjects indicated that counting backwards interfered with performance only when interpolated after errors, when stimulus-feedback information was withheld, but had an equivalent effect after errors and correct responses when stimulus-feedback information was available during ITI, indicating that different strategies were induced by the presence of such information.     

Sex differences in clerical speed: Perceptual encoding vs. verbal encoding

Most interpretations of sex differences on clerical speed tests have emphasized the role of rapid perception of details and shifts in attention. Some have emphasized comparison and decision processes. Sex differences in speeded, successive matching were studied in four experiments with college students. The experimental task involved the successive identification of stimulus items presented in lists by tapping matching items on response cards. Sex differences were found to be related to response-card content and not to stimulus-list content. When the identification response involved tapping words, colors, or directional symbols, females were significantly faster than males; however, when the identification response involved tapping shapes, no significant sex differences were found. Results indicated that sex differences in some aspect of short-term memory may also be involved. Earlier interpretations of sex differences on speeded matching tasks in terms of such global concepts as perceptual speed are believed to be inadequate. An alternative explanation is discussed emphasizing verbal encoding, memory, and evaluation processes.     

Auditory and visual confusions: Evidence against simple modality encoding hypotheses

Using both recognition and recall responses, confusion and intrusion errors were obtained for briefly exposed 11-letter strings. The patterns of errors were sharply dependent upon experimental variables. In Experiment I Ss made auditory and visual intrusions with recall, but neither with recognition. In Experiment II increasing exposure time and eliminating a poststimulus cue primarily increased auditory confusions. This suggests that auditory and visual confusions reflect strategy-contingentrecoding rather than modality-specificencoding.