Visual backward masking as measured by voice reaction time

Instead of using percent correct identifications or detections as the dependent variable, latency in voicing the target stimulus was measured in a backward masking paradigm. Reaction time (RT) to target letters was reliably increased when they were simultaneously encircled by a black ring mask of a size found to produce masking using an identification or detection criterion. The masking function in terms of RT was typical in shape, a decreasing function of stimulus onset asynchrony (SOA) over an interval of 150 msec. Since the target remained “on” when the mask appeared, the results are incompatible with an erasure interpretation of masking effects. Analyses of the variances of the RTs supported an interpretation of a progressive decrease in masking effects as SOA increased.     

The effects of area and perimeter on detection rates

The detection of luminance increments in a homogeneously lighted field was studied as a function of the area and perimeter of the luminance increment. Sixteen targets representing all possible combinations of four values of area and four values of perimeter were foveally presented. Exposure durations were short (25 to 40 msec). Results of both an analysis of variance and linear discriminant analysis indicated that detection probability increases as area increases, but neither variations in perimeter nor perimeter-area combinations produced effects that were significant oyer the experiment as a whole. The linear discriminant analysis revealed individual differences in the effects of perimeter and area on detection probability. Results were contradictory to Kristofferson’s (1957) “element contribution theory” and gave only slight support to Hecht’s (Lamar, Hecht, Shlaer, & Hendley, 1947) “border-quantum theory.”     

Binocular summation in the perception of form at brief durations

Visual form identification at brief durations was studied under: (a) monocular presentation; (b) dichopic presentation where the same form was presented successively on noncorresponding areas; and (c) dichopic presentation where the same form was presented on corresponding areas simultaneously and successively. Form identification for noncorresponding area dichopic presentation was at the level to be expected from 2independent chances to perceive. Both simultaneous and successive dichopic presentation on corresponding areas gave identification accuracy significantly above the level predicted by the assumption of independence. However, the binocular summation was not complete. When the same amount of energy entering the visual system in a binocular presentation was given in a monocular stimulation, the latter condition gave significantly better identification.     

How much processing do nonattended stimuli receive? Apparently very little, but...

The early versus late selection issue in attention models was examined by means of a new methodology. Through cues or precues, attention was directed to one location of a multistimulus visual display and, while attention was so engaged, the identity of a stimulus located at a different position in the display was changed. By varying the time after display onset before the stimulus was changed, we controlled the preview time that the original stimulus was represented on the retina. Then, using a marker cue, we directed the subject's attention to the location of the changed stimulus. The subject's response was a timed discrimination between two possible target letters. The data of main interest was the effect of preview time upon the subject's latency in identifying the new target that appeared in the changed location. We found that the preview time of the original stimulus, before RT was affected to the new target, depended upon whether the original stimulus was a neutral (noise) letter or whether it was the alternative target. When the original stimulus was a noise letter, RTs to the new target were just as fast as those obtained in the control condition in which the target was present throughout the preview interval and did not change its identity. Significant effects upon RT were obtained at preview times of 83 msec when the original stimulus was one of the targets that changed to the alternative target. Preview times also varied as a function of precuing. Preview times were correspondingly shortened when the first cue occurred 50 msec before display onset, thus providing an extra 50 msec for attention to be directed to the first display location. The results were interpreted in terms of two separate information-processing systems in the human: an automatic system and an attentional system. Even though a stimulus may have been automatically processed, when the attention system is directed to that stimulus, processing starts at the beginning again.     

Response competition effects insame-different judgments

An account ofsame-different discriminations that is based upon a continuous-flow model of visual information processing (C. W. Eriksen & Schultz, 1979) and response competition and inhibition between the responses by which the subject signifies his judgment is presented. We show that a response signifyingsame will on the average be executed faster due to less priming or incipient activation of the competing response,different. In the experiment, the subjects matched letters on the basis of physical identity. The degree of priming ofdifferent responses on same trials and ofsame responses ondifferent trials was manipulated by an extraneous noise letter placed in the display. Latency for judgments onsame trials increased as the feature overlap of noise and target letters decreased. Latencies were shorter ondifferent trials when the noise letter was dissimilar to either target letter than when the noise letter was the same as one of the targets. These results were consistent with the response-competition interpretation.     

Opposing effects of phonological similarity on item and order memory of words and nonwords in the serial recall task

This study shows that the classical phonological similarity effect (PSE) in immediate serial recall is critically affected by the lexicality of list items, the type of phonological similarity involved, and the scoring procedure. PSE was present in the serial recall score when phonologically distinct words were compared to words that share the middle vowel and end consonant (rhyming lists). PSE was absent in the serial recall score when phonologically distinct words were compared to words that share the initial and final consonants (consonant frame lists). There was a reversal of PSE in serial recall of nonwords when comparing distinct lists to both types of similar lists. Recall accuracy on the other hand was higher for distinct lists regardless of lexicality. Item errors dominated in relation to order errors in the case of nonwords, whereas order errors dominated in relation to item errors in the case of words. Furthermore, order errors were more common for phonologically similar lists, whereas item errors were more common for phonologically distinct lists. This may be the result of intra-list and inter-list interference, respectively. The dominance of the former error type may cause a classical PSE, whereas the dominance of the latter error type may cause a reversal of PSE. Finally, an item identification task yielded no evidence of an association between intra-list interference and discriminability of items in a list.     

Gender minority as a risk factor of exposure to bullying at work: The case of male assistant nurses

The aim of this study was to test the hypothesis that male assistant nurses, representing a small gender minority in their profession and in the work organizations they inhabit, are more often exposed to bullying at work than their female colleagues. In 1999, a random sample of the assistant nurses organized in the Norwegian Union of Health and Social Workers were mailed a questionnaire; 7478 out of 12,000 (62.3%) completed the questionnaire. The sample of the present study comprised the 6485 respondents who were vocationally active and not on leave. 3.8% (n?=?247) of the respondents were men; 10.2% (n?=?25) of the men and 4.3% (n?=?265) of the women reported that they had been exposed to bullying at work during the previous 6 months, χ²?=?19.12, df?=?1, p?<?.0001. The association between gender and exposure to bullying at work remained strong and significant (odds ratio?=?2.29; 95% confidence interval?=?1.39?-?3.78; p?=?.001) even after adjustment for a series of background factors. The study supports the hypothesis that male assistant nurses are more often exposed to bullying at work than their female colleagues.