On the detectability of straight lines in visual noise: An extension of French’s paradigm into the millisecond domain

We report the results of a study that investigated the effects of four experimental parameters on the tachistoscopic detectability of dotted lines in a noisy background consisting of dynamic patterns of identical dots. Characteristics of the lines that were explored included dot spacing, dot numerosity, and line orientation. Dot spacing was shown to be the most powerful parameter in determining the masking effect: the closer the dots, the more easily the line was detected. Increasing the number of the dots was also effective in increasing the detectability of a line, but only up to a limit of five dots. The orientation of the line, on the other hand, did not alter its detectability. Increasing the density of the visual masking noise monotonically reduced the detectability of the line. These studies are an extension of French’s (1953, 1954) work, differing mainly in the fact that the stimulus material was presented tachistoscopically rather than in a mode that allowed prolonged (up to 5 sec) examination of the figures. Thus, they put the results in a domain in which physiological interpretations may be more critically evaluated. A comparison of the results suggests that essentially the same sorts of cognitive mechanisms are operating in the millisecond domain as in the longer exposures. This suggests that simple neurological models utilizing the concept of feature filters or detectors may be being prematurely applied to relatively complex perceptual processes.     

Triadic consistency and false heart-rate feedback

Subjects viewed slides of the Rorschach cards while listening to heart sounds that were supposedly but not actually their own. For some of the subjects the heart rate increased when they were exposed to the five achromatic cards and for some subjects the heart rate increased when they were exposed to the five chromatic cards. In addition, some subjects were told that increased heart rate was a sign of mental health (positive condition), and some that the increased heart rate was a sign of mental abnormality (negative condition) Since the heart-rate increase (behavior) and Rorschach cards associated with the increase (attitude object) are connected by a positive causal relation, triadic theory predicts that the sign of the heart-rate increase should generalize to the associated cards (i e, be positive in the positive condition and negative in the negative condition) An analysis of variance revealed such an overall significant effect Closer examination of the data, however, revealed that the triadic effects were not unambiguously occurring when the increased heart rate was associated with achromatic cards It was suggested that in this condition the unique characteristics of the cards facilitated the generation of complicating anxiety. Supportive data for this interpretation were offered     

A Bayesian prediction of four-look recognition performance from one-look data

The hypothesis that a human O’s (S’s) performance in a visual recognition task can be modelled by Bayes’ theorem was investigated. Two Ss were run for 40 experimental sessions each. Their task was to specify the direction of the gap of tachistoscopically presented Landolt rings (Cs). There were four possible gap directions, and two experimental conditions. In one condition, S responded after each stimulus presentation. In the other, a fixed-observation condition, Ss responded after four consecutive presentations of a C. Exposure durations were such that performance under both conditions was greater than chance, but less than unity. Predictions of four-look performance from one-look data were made. Overall hit rates were predicted closely. The entire pattern of each S’s four-look data was also predicted reasonably well. Further tests of the model are currently under way.     

CHANGING PROTECTIVE AND RISKY BEHAVIORS TO PREVENT CHILD-TO-PARENT TRANSMISSION OF CYTOMEGALOVIRUS

Child-to-parent transmission of cytomegalovirus may be reduced by increasing protective behaviors (handwashing and glove use) and decreasing risky behaviors (intimate contact between child and parent). This study showed that an educational intervention resulted in increases in reported and objective measures of protective behaviors and decreases in reported risky behaviors. Further study must determine if changes in protective and risky behavior are maintained and prevent cytomegalovirus transmission.     

The effects of hormones,Type A behavior pattern,and provocation on aggression in men

Thirty-eight male college students, classified as either Type A or Type B based on their Jenkins Activity Survey (JAS-T) scores, competed in a reaction time task that allowed them to administer shocks to an increasingly provocative fictitious opponent. Salivary testosterone and cortisol were measured both prior to and after the task. Aggression was defined as the level of shock the subject was willing to set for the opponent. The results of this study indicate that a relationship exists between endogenous testosterone levels in men and direct physical aggression. Some evidence for the moderating effects of hormones on the level of aggression expressed by Type As was observed. No direct relationship between Type A and aggression was found.     

Variations on incremental interpretation

The strict competence hypothesis has sparked a small dialogue among several researchers attempting to understand its ramifications for human sentence processing and incremental interpretation in particular. In this paper, we review the dialogue, reconstructing the arguments in an attempt to make them more uniform and crisp, and provide our own analyses of certain of the issues that arise. We argue that strict competence, because it requires a synchronous computation mechanism, may actually lead to more complex, rather than simpler, models of incremental interpretation. Asynchronous computation, which is arguably both psychologically more plausible and conceptually more basic, allows for incremental interpretation to fall out naturally, without additional machinery for interpreting partial constituents. We show that this is true regardless of whether the presumed interpretation mechanism is top-down or bottom-up, contra previous conclusions in the literature, and propose a particular implementation of some of these ideas using a novel representation based on tree-adjoining grammars.The research in this paper was supported in part by grant IRI-9157996 from the National Science Foundation to the first author. The authors would like to thank Fernando Pereira, Edward Stabler, and Mark Steedman for discussions on the topic of this paper and for their comments on previous drafts.     

Lexical integration across saccades in reading

Summary Eye movements were recorded during sentence reading to examine the integration of parafoveal text across fixations. Four viewing conditions were used, each affording full view of the directly fixated word: no preview of the spatially adjacent parafoveal word; preview of its beginning trigram; preview of its beginning four letters; or preview of all its constituent letters. The magnitude of parafoveal-preview benefits (the difference between the no-preview condition and the different parafoveal-preview conditions) was examined as a function of the size of the saccade to the parafoveal target and as a function of the subsequent fixation location at the previewed target. The results revealed no effects of saccade size on parafoveal-preview benefits, but large effects of fixation position during the initial target fixation. Furthermore, parafoveal previews were used during the initial target fixation and during subsequent intratarget refixations. The results support a lexical-text-integration hypothesis which posits that lexical information is integrated across interword fixations and intraword refixations.     

Working with older adults and their families – a review

This paper discusses family work with older adults by exploring some of the related literature published since Herr and Weakland's work in 1979, and compares psychoeducational and systems-based approaches to work with later life families. Issues of bias and omissions in the existing literature, and the definition of family therapy with this client group are raised. Areas for future research are indicated.