Reaction time as a function of stimulus intensity for the monkey

Monkeys were trained to release a telegraph key in response to a visual or auditory stimulus. The latency of the key release response was measured for different stimulus intensities. In general, the relation between latency and intensity is inverse and exponential with greater variability of latency at the lower intensities. Some preliminary data involving differential reinforcement of short latencies are presented.     

Reaction time in reading a tachistoscopic display for a memory set item

Reaction times were measured in a task which requires the subject to search a brief visual array for a critical letter embedded in a row of background letters. In Experiment 1, the position of a critical letter in an instructed reading order and the size of a set of memorized letters were varied. Mean reaction time increased monotonically with distance of the critical letter from the beginning of the instructed reading path in the display. The variables reading position and memory set size were additive in their effect on mean reaction time. Data from a second experiment in which the retinal location of the critical letter and its reading position were varied showed that both reading position and retinal location influenced mean reaction time, but the effect of reading position on reaction time was greater. These variables interacted.     

Reaction time as a function of stimulus uncertainty on a single trial

In a discrete choice-reaction-time experiment, reaction times were measured between the onset of a light and the start of S’s pencil toward that light. The reaction time of unpracticed Ss, not aware that their first “practice” trial was being measured, increased as a linear function of stimulus uncertainty. Since this occurred without any prior experience, the effect must have been due to S’s set or expectancy regarding the nature of the future task, formed while the instructions for the task were being given.     

Reaction time to the onset and offset of electrocutaneous stimuli as a function of rise and decay time

Reaction times were obtained to the onset and offset of 70-cps electrocutaneous signals of five rise and decay times and five intensity levels. The results show that both onset and offset RTs increase linearly with increased rise and decay times. With fast rates of rise or decay, the onset produces faster RTs than the cessation of stimulation. The opposite effect is found when long rise and decay times are used. Interpretations of these results are given in terms of neural adaptation and accommodation.     

Reaction time to the onset and offset of electrocutaneous stimuli as a function of rise and decay time

Reaction times were obtained to the onset and offset of 70-cps electrocutaneous signals of five rise and decay times and five intensity levels. The results show that both onset and offset RTs increase linearly with increased rise and decay times. With fast rates of rise or decay, the onset produces faster RTs than the cessation of stimulation. The opposite effect is found when long rise and decay times are used. Interpretations of these results are given in terms of neural adaptation and accommodation.     

Premature termination as a function of intake data based on ethnicity, gender, socioeconomic status, and income

Although it is acknowledged that premature termination is detrimental to the therapy process, there is limited information on how to utilize client demographic data to indicate which clients have greatest potential to prematurely terminate. The study assessed how client ethnicity interacts with client gender, therapist gender, therapist ethnicity, and client socioeconomic status (education and income) to affect premature termination. The study consisted of 527 cases which received therapy services from the Auburn University Marriage and Family Therapy Center from October 1993 to October 1999. The three definitions of premature termination used were termination after one session, prior to six sessions, and by therapist report. Results indicated that interactions of client income and ethnicity and therapist gender and ethnicity were the most useful demographic data indicators of premature termination.     

Reaction time as a function of the intensity and probability of occurrence of vibrotactile signals

Three Ss made judgments of the presence or absence of a burst of 60-cps vibration onthe index fingertip.The probability of S’s reporting the presence of a signal was found to be influenced by signal probability and signal intensity. Mean reaction time for reporting the presence of a signal decreased as a function of signal intensity and signal probability whereas mean reaction time for reporting the absence of a signal increased as a function of signal intensity and signal probability. On trials where no signal was presented mean R T for reporting a signal decreased with increases in the signal probability whereas mean RT for reporting the absence of a signal increased with increases in signal probability. The results were interpreted as support for the hypothesis that S’s decision time was longer the closer on the sensory continuum a particular observation was to his criterion.     

Reaction time to a second stimulus as a function of intensity of the first stimulus

Reaction time (RT) to the second of two stimuli presented in rapid succession was examined as a function of the intensity of the first stimulus (S₁). It was found that the delay in RT₂ was greater following a dim first stimulus than following a bright first stimulus. The magnitude of this increase corresponded to the difference in RTs to the two intensity levels of S₁. These results support the prediction of a single channel model of response selection. Examination of mean first RTs revealed a general elevation in latency of RT. However, since this increase was not influenced by the inter-stimulus interval (ISI) or by the intensity of the second stimulus (S₂), and since the same increase was found on “catch trials“ where no S₂ was presented, this increase is considered to be a function of change in set in the double response situation.     

Useful resolution for picture perception as a function of eccentricity

Observers inspected for different lengths of time pictures which contained high-resolution information within an eye-contingent viewing window and low-resolution information outside the area of that window. A recognition test followed in which the pictures inspected were presented together with other, distractor, pictures. The time required to reach 75% picture recognition (the criterion study time) was determined as a function of window size and degree of completeness of video sampling of information outside the window. For each level of information sampling density, criterion study time decreased as window size increased up to a critical size, and then remained approximately constant beyond this size. From these critical-window sizes, a function which describes the resolution actually used by the visual system at each eccentricity (the useful-resolution function) was obtained and this decreased monotonically with eccentricity. The useful resolution at each eccentricity was coarser than the resolution available at that eccentricity as determined by visual acuity, suggesting that useful resolution is not limited by visual acuity. The relationship between useful resolution and saccade length was also analyzed.     

Influence tactics as a function of gender,insult, and goal

A laboratory procedure evaluated three theoretical frameworks commonly used to explain gender differences in influence behaviors: the intrapersonal, which predicted main effects for gender; social context, which predicted main effects for situational variables; and sex stratification, an extension of expectation states theory, which predicted gender by situation interactions. Results supported the latter theory, indicating that goals (self-interest or altruism) and target behavior (insulting or not insulting) differentially affected women's and men's behavior. The relative use of reward, coercion, and request influence strategies was examined. Males and females increased their use of each strategy type differentially across trial blocks. Females used request and males used reward increasingly across trial blocks. Only males who were insulted showed an increase in coercion. Contrary to stereotypes, results suggest that males and females may hold similar preferences for strategies they use most to least often, but may switch their choices at different rates.The assistance of the UNCG Research Council and Statistical Consulting Center is acknowledged. Appreciation is expressed to Jacqueline Goodchilds and Barbara Wallston for comments on an earlier draft. This article is dedicated to the memory of Barbara Wallston, who believed in the importance of research on power and gender.     

Adult perceptions of the infant as a function of gender labeling and observer gender

Four hundred sixty four adults rated a videotape of the activities of a 22-month-old infant whose gender was labeled differently with different subject groups. One group was told that the infant was male, a second group was told that the infant was female, and a third group was told that the infant was hermaphrodite, i.e., appeared to have the genitals of both sexes. Some subjects rated each activity as being either masculine or feminine (forced-choice method) while other subjects rated each activity with a neutral choice also available (free-choice method). The data indicate that, for both methodological groups, labeling the infant “male” resulted in significantly more activities being rated masculine than feminine, whereas the converse was true when the infant was labeled “female.” A label of “hermaphrodite” resulted in an approximately equal ratio of activities being rated as masculine and as feminine. There were no significant interaction (Gender Label × Observer Gender) for the forced-choice group, but for the free-choice group, significant interaction between child's gender label and observer's gender was found.     

Use of normative peer data as a standard for evaluating classroom treatment effects

This study illustrated the use of normative behavioral observation data as a standard for evaluating the practicality of treatment effects produced in other settings. Three groups of eight subjects each, displaying relatively low proportions of appropriate classroom behavior when compared with regular classroom peers, were selected for treatment within an experimental classroom setting. The three groups were exposed to intervention procedures designed to reinforce either direct academic performance and/or facilitative nonacademic classroom responses. The treatment was effective in changing levels of appropriate behavior (1) above baseline levels in the experimental classroom, and (2) to within normal peer-defined limits when reintegrated into the regular classroom. Further, the data reflect successful maintenance of these effects for a seven- to 12-week follow-up period. Several applications of a normative model for evaluating treatment, generalization, and maintenance effects were presented and discussed.     

Interresponse time as a function of continuous variables: a new method and some data

A cathode-ray oscilloscope and a Polaroid camera record interresponse times as a function of time, stimulus wavelength, and similar variables. Each response flashes a point of light on the oscilloscope screen; the vertical position of the point gives IRT, the horizontal position gives the value of the other variable. Several thousand such points may be recorded on a single frame of film, and the density of the points indicates the relative frequency of various IRTs. The method has the advantages of a two-dimensional display of continuous variables, flexibility, speed, and relatively low cost. It lacks the advantage of a digital output. Figures show IRTs of pigeons on VI, FR, DRL and extinction, and transitions among these, and also the results of stimulus generalization tests. The results have some provocative features that require much further exploration. Among other things, they suggest that "response rate" as a measure usually includes a response-dependent component that is insensitive to changes in other variables.