Division of attention between simultaneous and successive nonverbal signals varying in discriminability

Impaired performance indexed by accuracy usually accompanies the division of attention between simultaneous difficult signals. Presenting the signals successively reduces the impairment. Presenting easy signals eliminates it. Both variables crucial to these findings, relative time of onset and discriminability, were manipulated in the first experiment using a two-choice recognition paradigm involving bimodal signals. The results showed that, when a difficult signal was followed by two simultaneous easy ones, in a different modality from the first, performance was significantly worse on each than on the same signals presented alone. Simultaneous presentation of all three signals further increased the impairment for the difficult signal, but not for the easy ones. In the second experiment, the discriminability of the following signals was varied. The results showed, that when a difficult signal was followed by either two simultaneous easy signals, in a different modality from the first, or by two difficult ones, performance was significantly worse than on the same difficult signal presented alone. Further, when the preceding difficult signal was auditory, but not when it was visual, performance was better with easy following signals than with difficult ones. It is argued that an adequate account of the results from the two experiments requires the following assumptions concerning the processing of multiple signals: (1) a loss associated both with the acquisition and the storage of information, (2) preferential processing of visual signals over auditory ones. Proposals are made for the incorporation of both assumptions into a single model of divided attention.     

Contextual assimilation and its effect on the division of attention between nonverbal signals

Subjects performed a recognition task in which a low or a high frequency signal was presented simultaneously with a dim or a bright intensity one. The independent variable was the degree of association between the signals on the two dimensions. Unknown to the subjects four levels were tested in separate conditions, 1.0, 0.8, 0.5 and 0.2. Increasing the positive association improved overall sensitivity as measured by d' on both dimensions, but left contingent sensitivity unchanged. Changing the association did not affect overall bias, as measured by Beta. However, holding context constant by analysis produced significant differences between individual measures of contingent bias in the direction of assimilation, for example “low” responses tended to accompany dim signals and “dim” responses. The differences were unaffected by the changes in association. The results are interpreted as favouring models of contextual assimilation which assume that biasing at some level of processing depends upon the mutually contingent interaction of discrete events rather than on memory and expectation of the relative frequency of conjoint events. Further support for this conclusion comes from previous studies which indicate that assimilation occurs with separate responses but not with unitary ones. The implications of the findings for research on the division of attention are discussed, particularly the need to control variability in measured bias to establish a true change in the allocation of attention. Two generalized models of contextual assimilation are proposed, one based on “object” and the other on “lexical” assimilation. The possible application of these models to synaesthesia is considered.     

To reverse or not to reverse: when is an ambiguous figure not ambiguous?

The role of bottom-up processes in our perception of reversible figures was examined. In Experiment 1 the overlapping squares figure and nonsense reversible figures were used. The effects of adapting subjects for differing durations to an unambiguous version of the figure before presentation of the traditional reversible figure were determined under conditions of varying precision of fixation. In Experiment 2 the research was expanded to other examples of reversible figures. In both experiments, results with two dependent measures (the subject's first percept and the number of reversals reported) were generally consistent with the interpretation of bottom-up processes underlying the adaptation effects. However, the crucial role of stimulus and procedural variables and the differential sensitivity of the two dependent measures was demonstrated.     

Parallel and competitive processes in hierarchical analysis: perceptual grouping and encoding of closure.

The role of perceptual grouping and the encoding of closure of local elements in the processing of hierarchical patterns was studied. Experiments 1 and 2 showed a global advantage over the local level for 2 tasks involving the discrimination of orientation and closure, but there was a local advantage for the closure discrimination task relative to the orientation discrimination task. Experiment 3 showed a local precedence effect for the closure discrimination task when local element grouping was weakened by embedding the stimuli from Experiment 1 in a background made up of cross patterns. Experiments 4A and 4B found that dissimilarity of closure between the local elements of hierarchical stimuli and the background figures could facilitate the grouping of closed local elements and enhanced the perception of global structure. Experiment 5 showed that the advantage for detecting the closure of local elements in hierarchical analysis also held under divided- and selective-attention conditions. Results are consistent with the idea that grouping between local elements takes place in parallel and competes with the computation of closure of local elements in determining the selection between global and local levels of hierarchical patterns for response.     

汉字部件信息数据库的建立──部件和部件组合频率的统计分析

用ＦｏｘＢＡＳＥ语言统计了６７６３个基本汉字集合中的部件和部件组合的频度信息,建立了“部件数据库”和“部件组合数据库”。前者包含５６７个部件;后者包含汉字中实际存在的７５８３个两部件组合。统计结果表明部件和部件组合均呈偏态分布,绝大多数的频率很低。这两个数据库不仅可应用于研究汉字认知中整体和局部的关系、汉字的学习和记忆,而且也可供汉字学的定量研究、中文信息的计算机处理研究参考。     

Iontophoretically applied potassium ions as an experimental pain stimulus for investigating pain mechanisms

The present study investigated the psychophysical characteristics of potassium iontophoresis and its suitability as an experimental pain stimulus. Experiment 1 investigated the optimal duration of the pain stimulus for reliable reporting across repeated trials and whether the relationship between stimulus and subject response was linear, logarithmic, or a power function. In Experiment 2, the optimal interstimulus interval (ISI) was determined for reliable pain reporting, and stimulus history effects, both in terms of session effects and the effects of immediately preceding stimuli, were evaluated. In Experiment 3, potassium iontophoresis was compared with a sodium iontophoresis control. Linear functions described the stimulus-pain relationship best. No significant differences in the goodness-of-fit coefficients of determination, correlations, or coefficients of variation were found for the stimulus durations of 1, 2, and 4 sec. Significant stimulus history effects were found across a session, with adaptation and enhancement of responding for low- and moderate-intensity stimuli, respectively. The effects of the immediately preceding stimuli were suppression or enhancement of pain response, depending on the ISI, the preceding stimulus intensity, and the present stimulus intensity. Potassium iontophoresis was a significantly more effective pain stimulus than was sodium iontophoresis. It was concluded that potassium iontophoresis is a convenient and reliable experimental pain stimulus, which can be presented rapidly and repeatedly with minimal loss in consistency of subject pain report. Potassium iontophoresis provides a tool for investigating the neural modulation of pain in the relative absence of inflammation processes and tissue damage.     

The Masculinity-Femininity Scale of MMPI-2: is it useful with normal men?

Using ratings provided by significant others, we examined characteristics of 819 normal men whose scores on the Masculinity-Femininity scale (Scale 5) of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) ranged from low to high. Also examined were the possible effects of educational level as a moderator variable. Only one external characteristic was correlated with Scale 5 scores at a level of significance that could not be attributed to chance, and that correlation was negative, whereas previous literature indicated a positive relationship. The findings were essentially the same whether or not the effects of education were controlled. Regardless of Scale 5 scores and the higher the men's educational levels, the more positive were ratings by their partners. In general, the results do not support the usefulness of Scale 5 in describing the personalities and behaviors of normal men.     

A short-term longitudinal examination of young adolescent functioning following divorce: The role of family factors

The purposes of this study were to examine young adolescent functioning over a 2-year period after divorce and to assess the role of two family factors, interpersonal conflict and the parent-adolescent relationship, in predicting such functioning. One hundred and twelve young adolescents, their mothers, and their social studies teachers served as participants. One-half of the adolescent were from recently divorced families and one-half were from married families. Mothers completed measures concerning interparental conflict and the parent-adolescent relationship, adolescents completed a measure of the relationship, and teachers completed measures assessing four areas of adolescent functioning. The results indicated that adolescents from divorced families were functioning less well than those from married families. There were no changes in adolescent functioning and the parent-adolescent relationship from the first to second year postdivorce. High levels of interparental conflict in divorced families were associated with more parent-adolescent relationship problems. In turn parent-adolescent relationships problems served as the best predictor of concurrent and subsequent difficulty in adolescent functioning.This study was supported, in part, by the William T. Grant Foundation and the University of Georgia's Institute for Behavioral Research.     

Individual differences in Stroop dilution: tests of the attention-capture hypothesis.

Kahneman and Chajczyk (1983) found that naming a colored bar was slowed when a color word was nearby but that this decrement was reduced when a neutral word was also present. This has been referred to as the dilution effect. They accounted for their results with an attention-capture hypothesis. Response time distributions to stimuli that contained a color word and a neutral word within individuals were examined. The dilution effect did not appear within individuals. Some individuals exhibited strong Stroop interference effects, whereas others exhibited no interference. Experiment 2 showed that the interference pattern within individuals was consistent across days. Experiment 3 showed that performance could not be explained by a selection strategy that was based on word length. These experiments showed that performance in a color-plus-neutral word condition reflects a systematic pattern of interference or noninterference that varies across individuals.