A novel paradigm reveals the role of reentrant visual processes in object substitution masking

Object substitution masking (OSM) occurs when an initial display of a target and mask continues with the mask alone, creating a mismatch between the reentrant hypothesis, triggered by the initial display, and the ongoing low-level activity. We tested the proposition that the critical factor in OSM is not whether the mask remains in view after target offset, but whether the representation of the mask is sufficiently stronger than that of the target when the reentrant signal arrives. In Experiment 1, a variable interstimulus interval (ISI) was inserted between the initial display and the mask alone. The trailing mask was presumed to selectively boost the strength of the mask representation relative to that of the target. As predicted, OSM occurred at intermediate ISIs, at which the mask was presented before the arrival of the reentrant signal, creating a mismatch, but not at long ISIs, at which a comparison between the reentrant signal and the low-level activity had already been made. Experiment 2, conducted in dark-adapted viewing, ruled out the possibility that low-level inhibitory contour interactions (metacontrast masking) had played a significant role in Experiment 1. Metacontrast masking was further ruled out in Experiment 3, in which the masking contours were reduced to four small dots. We concluded that OSM does not depend on extended presentation of the mask alone, but on a mismatch between the reentrant signals and the ongoing activity at the lower level. The present results place constraints on estimates of the timing of reentrant signals involved in OSM.     

Age effects in backward visual masking (Crawford paradigm)

Fifteen Ss in each of four age groups (5-, 10-, 16-, and 22–23-years old) received backward visual masking. Group effects occurred at longer ISIs indicating slower prerecognition processing for younger Ss. In a second experiment 19-, 35-, and 55-year-old Ss were administered backward visual masking under the identical procedures of Exp. 1. The oldest Ss performed significantly worse than 19- and 35-year-old Ss, which did not differ significantly from each other. The general methodological features of both studies, as well as the obtained relationships were discussed.     

The crossmodal facilitation of visual object representations by sound: evidence from the backward masking paradigm

We report a series of experiments designed to demonstrate that the presentation of a sound can facilitate the identification of a concomitantly presented visual target letter in the backward masking paradigm. Two visual letters, serving as the target and its mask, were presented successively at various interstimulus intervals (ISIs). The results demonstrate that the crossmodal facilitation of participants' visual identification performance elicited by the presentation of a simultaneous sound occurs over a very narrow range of ISIs. This critical time-window lies just beyond the interval needed for participants to differentiate the target and mask as constituting two distinct perceptual events (Experiment 1) and can be dissociated from any facilitation elicited by making the visual target physically brighter (Experiment 2). When the sound is presented at the same time as the mask, a facilitatory, rather than an inhibitory effect on visual target identification performance is still observed (Experiment 3). We further demonstrate that the crossmodal facilitation of the visual target by the sound depends on the establishment of a reliable temporally coincident relationship between the two stimuli (Experiment 4); however, by contrast, spatial coincidence is not necessary (Experiment 5). We suggest that when visual and auditory stimuli are always presented synchronously, a better-consolidated object representation is likely to be constructed (than that resulting from unimodal visual stimulation).     

The effects of graphemic and phonemic similarity between targets and masks in a backward visual masking paradigm

Experiments using a backward visual masking technique are described, in which the second (mask) stimulus is itself masked by a third stimulus, thus rendering guessing strategies, about target/mask relationships, difficult for subjects. Word-word and word-non-word sequences are used for the first two stimuli and it is shown that when the second stimulus resembles the first, either physically or phonologically, the severity of masking of the first is reduced. However, the target is not better reported when the mask word is semantically related to it. Consideration is given to the levels at which interaction between target and mask might occur.     

A recognition masking study of consonant processing

The processing of consonants was investigated in a series of experiments using a recognition masking paradigm. Experiment I investigated the effects of target duration, interstimulus interval, forward vs. backward masking, and the phonetic feature composition of the target and mask on accuracy of target identification. Experiment II assessed consonant processing when the target and mask were presented dichotically in order to separate central and peripheral components of consonant masking. Experiment III investigated the effects of mask duration on consonant processing. Substantial masking was found in backward and forward diotic and dichotic conditions. Evidence for target-mask interaction at the level of phonetic features was also found.     

A Rational-Emotive paradigm for organizations

A case is made for incorporating a Rational Emotive paradigm within an organization setting. The paradigm consists of four separate, interconnected components: 1) Goals of the organization, 2) Management Effectiveness Training, 3) Staff Effectiveness Training, 4) Employee and Family Assistance Programs. The role of Rational Emotive theory is explained in terms of each component. Characteristics, attributes, and traits of employees working in a Rational Emotive Organization are postulated, and advantages to the organization are identified. A proposed ABC framework for the effective organization parallels the traditional model developed by Albert Ellis, founder of Rational Emotive Therapy.     

Vibrotactile masking: A comparison of psychophysical procedures

The amounts of ipsilateral and contralateral masking obtained with a modified psychophysical procedure were compared for vibratory stimuli presented to different body loci. Results of a combined forced-choice localization task and a forced-choice detection task were similar to the results obtained in previous investigations which employed method of limits and two-alternative, temporal forced-choice procedures, respectively. Ipsilateral maskers produced similar amounts of masking in both the detection and localization tasks for fingertip and arm test sites. Contralateral maskers resulted in considerably more masking in the localization task than in the detection task for both fingertip and arm test sites. When large longitudinal distances were introduced between the test stimulus and masker, little masking was evident in either the localization or detection task. It was concluded that the differences in the amount of ipsilateral and contralateral masking obtained with different psychophysical procedures reflect different effects of a masker on the detectable attributes of a test stimulus. Implications of these results for the study of multiple tactile perception were discussed.     

A service-delivery paradigm for personality assessment

This paper describes a human science approach to the delivery of the feedback component of assessment services. The feedback process is now central to a collaborative assessment that is integrated with intervention. Research has suggested that subject, situational, and assessor variables are relevant for feedback, but such research has been unsystematic. A service-delivery paradigm for feedback of assessment findings is described that includes four levels of increasing client participation: information, emotional contingencies, transfer of power, and functioning of an assessment system. Communication of assessment findings has been incomplete historically because motivation for feedback, resource accessibility for feedback utilization, and criteria for adequate feedback have been considered as unrelated ingredients. The components of Antonovsky's Sense of Coherence construct--meaningfulness, manageability and comprehensibility--provide one conceptualization for interaction of these ingredients. It is now feasible to do systematic research on assessment that includes feedback of assessment findings and the service-delivery process.     

Interhemispheric visual masking

Backward masking functions were evaluated in a paradigm in which target and masking stimuli were presented to opposite cerebral hemispheres using separate peripheral pathways. Backward masking occurred dichoptically when the target and mask were projected to opposite hemispheres. These findings indicated that some effective masking mechanisms are mediated by interhemispheric interactions independent of retinal phenomena.     

A paradigm shift in Heidegger research

The Beiträge zur Philosophie mandates a paradigm shift in Heidegger scholarship. In the face of (1) widespread disarray in the current model, the new paradigm (2) abandons Sein as a name for die Sache selbst, (3) understands Welt/Lichtung/Da as that which gives being, (4) interprets Dasein as apriori openedness rather than as being-there, (5) understands the Kehre as the interface of Geworfenheit and Entwurf, not as a shift in Heidegger's thinking, (6) interprets Ereignis as the opening of the Da rather than as appropriation, and (7) understands human finitude as what gives all forms of being and all epochs in the history of being. The conclusion alludes to the function of Mitdasein (co-openness) as die Sache selbst.     

A masking approach to the problem of form perception

The effects of deletion of certain components of a dotted triangle are studied, using a masking technique. Masking interference is achieved by varying the density of randomly placed dots within which stimulus triangles must be detected. The results of the study indicate that deletion of the dots composing the corners of the triangles decreases performance no more than deletion of an equivalent number of randomly chosen dots. However, the detectability of the line of dots composing the sides is functionally related to the recognition of the orientation of the triangle. The results suggest that the relationship of the parts of such a stimulus figure may be more important than the specific parts themselves.     

Frequency selectivity using tonal-temporal masking: Diotic vs. dichotic masking

A combined forward-backward masking procedure was used to investigate the threshold of a 30-msec, 500-Hz signal as a function of masker frequency. The signal thresholds were obtained in two signal conditions, diotic (So) and dichotic (S_π), and for two different temporal separations of the maskers. The maskers were 500 msec in duration and were presented at 75 dB SPL. The function relating masked signal threshold to masker frequency was used to describe frequency selectivity in the four conditions. There were no differences in frequency selectivity measured between the diotic and dichotic signal conditions and only a small difference measured between the two intermasker interval conditions. The S_π conditions yielded lower thresholds than did the So conditions. The change in intermasker interval from 10 to 50 msec lowered the threshold maximally 18 dB for the So condition and 13 dB for the S_π condition. The results indicate that in this tonal temporal masking procedure there are no differences between the diotic and dichotic critical bands.     

Educated insane: A nineteenth-century psychiatric paradigm

In the 1830s the time-honored notion that excess study could lead to madness underwent a significant change in America. Under the influence of Enlightenment pedagogy and phrenology, influential superintendents like Amariah Brigham and Isaac Ray feared that the “unnatural” overstimulation of children in schools would ruin their development. In the second half of the nineteenth century, as belief in environmental determinism waned and assumptions about what is “natural” changed, this psychiatric etiology was debated; then, overthrown. By the turn of the century, education was thought to aid, not harm, the mentally ill.     

Transient and sustained masking

The detection threshold of a brief test stimulus was measured as a function of the onset asynchrony between it and a long-lasting suprathreshold masking stimulus. Both stimuli were sine-wave gratings of the same vertical orientation and in the peak-subtract phase but differed in spatial frequency by a factor of 3. The temporal masking functions obtained with 2- and 6-cycles/deg maskers of high contrast exhibited transient on- and off-peaks of masking and a sustained effect during the masker exposure. An 18-cycles/deg masker caused sustained masking only. Experiments with maskers of variable spatial frequency and contrast showed that, in the low-spatial-frequency range, the mechanism responsible for the transient effect was more sensitive than that generating the sustained effect, while the sustained effect required less contrast in the high-spatial-frequency range. The results are considered as evidence, in addition to previous findings, for the sustained/transient dichotomy in the temporal domain.