A rapid technique to assess the resting states of the eyes and other threshold phenomena: The Modified Binary Search (MOBS)

A technique was developed to automate subjective measurement of the resting states of the eyes. This technique, the Modified Binary Search (MOBS), evolved from the binary search and a commonly used manual bracketing technique. The procedure is mathematically and logically simple, and it requires minimal storage and computation capabilities. Monte Carlo simulations indicate that the MOBS procedure provides more precise measures with fewer stimulus presentations than conventional staircases. It is also relatively insensitive to response errors.     

The second androgyny: A proposed revision in adaptive priorities for college women

Evidence has accumulated suggesting that androgyny, as popularly conceived (i.e., balanced and flexible display of masculine and feminine behaviors across situations), has more adaptive value for women than for men and even that it holds less value than believed for women. Four sex types were compared in a series of studies bearing upon psychological adjustment in college women: (1) balanced androgyny, (2) blended androgyny that integrates masculinity and femininity, (3) femininity, and (4) masculinity. In three out of four studies that considered daily stress symptoms, Type A characteristics, and menstrual distress, balanced androgynes demonstrated the poorest psychological adaptation and blended androgynes the best. The fourth study considered the psychological characteristics associated with eating disorders and found feminine women to be the most maladapted. Interpretation of the trend of results in terms of identity problems for the balanced androgynous woman was offered.     

When visual search functions look like item recognition functions

Visual search data were collected from six Ss on three target set sizes on each of 30 days. Error level was low, and items assigned to memory sets were nonnested and changed from session tosession. For each S. the same item sometimes required a positive and sometimes a negative response (response inconsistency). Combining data over Ss and over successive 6-day blocks, visual search rates as a function of target set size were found to be linear for each of the five 6-day blocks. The slopes of the above functions (memory search time) did not differ significantly over the final four 6-day blocks, and averaged approximately.500 sec per six-character item. These results are qualitatively very similar to results obtained from item recognition studies when error level, memory set structure, degree of response’_ consistency, and practice are handled in the same way in that task. The significantly lower slope obtained on the first 6-day block is shown to be consistent with a speed-accuracy trade off interpretation when error rate is expressed per unit of processing time (percent errors/set size). Over the final three 6-day blocks, where all important parameters ofthe data were highly stable, the intercepts of the memory search functions were found to closely approximate zero, averaging .0068 sec. From this finding, along with the finding that the memory search functions are linear, it is inferred that visual search time is determined entirely by memory search time, or by memory search time and other processes which increase linearly with set size, under the conditions of this experiment. The estimate of memory search time (approximately 83 msec/character) obtained using this visual search procedure is much slower than that obtained using the item recognition procedure (approximately 35\2-40 msec/character). An explanation for this difference is proposed.     

A real-time criterion theory of duration discrimination

The common idea that a measure is taken of a duration stimulus over its temporal extent, and that the decision as to whether the stimulus is relatively long or short is based upon such a measure, is shown to be incorrect. Two experiments, which require speeded responding in duration discrimination and consider response latencies as well as response probabilities, demonstrate that the response that is made is determined by the outcome of a race between an internally timed interval, the criterion, and the presented stimulus. The onset of the stimulus triggers the criterion; if the criterion ends first, the response “long” is elicited. Duration discrimination is a matter of temporal order discrimination, and in the limit, “short” responses are simple reactions while “long” responses are time estimation responses. A specific model of the real-time criterion hypothesis is tested, and these initial tests generally confirm it. From this, it is concluded that errors in duration discrimination are due entirely to variability of the criterion and that afferent latencies are not necessarily variable. This adds additional evidence for the existence of deterministic afferent latencies.     

Effects of vestibular stimulation on motor development and stereotyped behavior of developmentally delayed children

Four developmentally delayed babies were given semicircular canal stimulation in an effort to facilitate their motor and reflex development. Each of the children also exhibited abnormal stereotyped movements. The theory was advanced that these movements are related to motor development and that significant improvements in motor abilities will produce changes in the intensity and/or form of stereotypic responding. Semicircular canal stimulation was provided by rotating the children in a motor-driven chair at a velocity of about 17 rpm for 10 minutes daily over a period of 2 weeks. Standard motor and reflex measures were taken before, during, and after the rotation treatment period. Daily observations were made of the children's stereotyped movements. Over the course of the study all of the children showed motor and/or reflex changes that were attributable to the vestibular stimulation. In addition, some evidence was obtained linking changes in stereotypic responding to the vestibular stimulation.This work was supported by PHS Grant Nos.HD15051 and HD13344.     

Observational studies of retarded children with multiple stereotyped movements

Stereotyped movements, such as body rocking and hand gesturing, are common among developmentally delayed children. However, very little is known concerning the naturally occurring circumstances that produce variability in this type of responding. Three relatively long-term observational studies, involving seven preschool children, each of whom exhibited multiple stereotypies, were conducted to determine the extent to which the type of activity or setting had any effect upon the rates of these responses. Repeated observations were made of each child during a variety of school activities. In two studies, adult-child interactions were also recorded. The results showed that, in general, the particular activity greatly affected rates of stereotyped behavior, although there were some marked individual differences. Moreover, in two studies variability was apparent across sessions within a particular setting. For some of the children, there was evidence that their multiple stereotypies were functionally interrelated. Adult interactions, as recorded in one study, appear to be both quantitatively and qualitatively different for stereotyping as contrasted with nonstereotyping children. An environmental analysis employing a sequential model indicated that there were teacher behaviors that affected the frequency and/or conditional probability of the child's aberrant behavior.This research was supported by P.H.S. Grant No. HD-00973.     

Misattribution of arousal and the effects of self-threatening information

Two experiments are reported on the effects of misattributing arousal. In both experiments, subjects took an intelligence test and received fictitious negative results about their performance. In the first experiment, subjects before receiving feedback were given a pill labeled as arousing; however, the ostensible effectiveness of the pill was varied. The greater the alleged strength of the pill, the less the test was derogated following feedback about performance on it and the more effort subjects reported expending on the test. In the second experiment, subjects were told that the pill was either arousing or relaxing and that its effect lasted for either a short or a long period of time. Initial test evaluations were more positive and estimates of effort expended were greater when the pill was described as arousing than when it was described as relaxing. However, whereas these differences were maintained over time when the pill's effects were described as of long duration, they disappeared over time when the pill's effects were described as of short duration.     

A quantal step function in duration discrimination

The difference threshold for duration, for the case of empty time intervals bounded by brief auditory pulses, is an increasing function of base duration. For base durations between 100 and 1,480 msec, Weber’s law describes the function quite well and a Weber ratio of .05 is obtained. These results in the present paper conform closely to results that have been reported by others. However, it is further shown that the function changes as the amount of practice is increased at each specific base duration: steps unfold from the linear function, and these steps are clearly evident after 17 consecutive sessions at each base duration. Expressing threshold in terms of the apparent magnitude of the “time quantum,” it is found that q is about 13 msec when base duration is 100 msec and that it jumps to 25 at 200, to 50 at 400, and to 100 at 800. Between the abrupt risers in this step function, the treads are not quite flat, perhaps because the amount of practice was insufficient. It is concluded that the time quantum can be doubled and halved, at least within the doubles set 13, 25, 50, and 100 msec. It is not restricted to the single value of 50 msec as initially proposed (Kristofferson, 1967).     

Dissociation of Processes Underlying Spatial S-R Compatibility: Evidence for the Independent Influence of What and Where

The process-dissociation procedure was used to estimate the influence of spatial and form-based processing in the Simon task. Subjects made manual (left/right) responses to the direction of arrows (> or <) presented to the left or right of fixation. Manipulating the proportion of incongruent trails (e.g., a right-pointing arrow presented to the left of fixation) affected both the size and direction of the Simon effect. To account for this pattern of data, we compared process estimates based on three possible relationships between spatial and form-based processing: independence, redundancy, and exclusivity. The independence model provided the best account of the data. Most telling was that independent form-based estimates were superior at predicting observed performance on arrows presented at fixation and did so consistently across conditions (r′s > .80). The results provide evidence that the form ("what") and spatial location ("where") of a single stimulus can have functionally independent effects on performance. They also indicate the existence of two kinds of automaticity—an associative ("implicit learning") component that reflects prior S-R mappings and a nonassociative component that reflects the correspondence between stimulus and response codes.