Two-stage model of visual backward masking: sensory transmission and accrual of effective information as a function of target intensity and similarity.

A functional model is used to describe the effect of target intensity and target-set similarity on backward visual masking. The model consists of two distinct stages of visual information processing. The first stage is related to sensory transduction and transmission and is assumed to require a finite and measurable amount of time during which performance remains at chance. The second stage, associated with central processing, is characterized by a negatively accelerated growth function reflecting the accrual of effective information. Results show that the duration of the transmission stage is inversely related to target intensity. Surprisingly, the rate of information accrual is an interactive function of both target intensity and target-set similarity. The pattern of results is consistent with the interpretation that both intensity and similarity mediate their effect through a common mechanism--the accrual of effective information.     

Aging and visual masking: sensory and attentional factors

Visual tasks can yield quantitatively similar patterns of performance that reflect different underlying mechanisms in younger and older observers. In 3 experiments, we used the visual masking task of J. T. Enns and V. Di Lollo (1997) to examine 2 of these mechanisms: stimulus contrast and attention. Performance appeared to be equivalent for younger and older observers in some circumstances, although manipulation of contrast and attention suggested that older observers may use focal attention to enhance the perceptual clarity of the target. For older observers, impoverished visual representations may more readily be eliminated by manipulation of attention or by the presence of a mask, indicating that both attention and stimulus quality are important influences on performance.     

Two-stage model of visual backward masking: Sensory transmission and accrual of effective information as a function of target intensity and similarity

A functional model is used to describe the effect of target intensity and target-set similarity on backward visual masking. The model consists of two distinct stages of visual information processing. The first stage is related to sensory transduction and transmission and is assumed to require a finite and measurable amount of time during which performance-remains at chance. The second stage, associated with central processing, is characterized by a negatively accelerated growth function reflecting the accrual of effective information. Results show that the duration of the transmission stage is inversely related to target intensity. Surprisingly, the rate of information accrual is an interactive function of both target intensity and target-set similarity. The pattern of results is consistent with the interpretation that both intensity and similarity mediate their effect through a common mechanism—the accrual of effective information.     

Integration,interruption and processing rate in visual backward masking

Summary The identification of a briefly presented test stimulus is impaired when the test stimulus is followed by a masking stimulus consisting of random contours. Two theories have been proposed to account for this effect (backward masking by visual noise). According to interruption theory, the time which is available for test stimulus processing is limited by the onset of the masking stimulus. According to integration theory, test stimulus and masking stimulus are combined in a single percept where the test stimulus is degraded by the contours of the masking stimulus. A review of the methods used to decide between the two theories permits the conclusion that backward masking by visual noise requires a two-factor theory: integration for short (less than about 100 msec) and interruption for long test stimulus-masking stimulus asynchronies. It is shown that evidence for interruption can only be obtained when processing load is used as a converging operation. Finally, some approaches to the measurement of processing rate under backward masking are discussed.

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Zusammenfassung Die Identifizierbarkeit eines tachistoskopisch dargebotenen Testreizes wird durch nachfolgende Exposition eines aus Zufallskonturen bestehenden Maskierreizes beeinträchtigt. Zur Erklärung dieser Maskierung durch visuelles Rauschen wurden zwei Theorien formuliert. Gemäß der Unterbrechungstheorie wird die zur Verarbeitung des Testreizes verfügbare Zeit durch die Darbietung des Maskierreizes verkürzt; gemäß der Integrationstheorie werden Test- und Maskierreiz in eine gemeinsame zentrale Repräsentation verwandelt, in der das Testreizäquivalent von den Maskierreizkonturen überlagert wird und dadurch eine Qualitätsminderung (degradation) erfährt. Die zur Entscheidung zwischen den beiden Theorien verwendeten Methoden werden analysiert, mit dem Ergebnis, daß die Maskierung durch visuelles Rauschen eine Zwei-Faktorentheorie erfordert: Integration für kurze (kleiner als ca. 100 msec) und Unterbrechung für lange Testreiz-Maskierreizintervalle. Es wird gezeigt, daß Unterbrechungseffekte nur dann nachgewiesen werden können, wenn die Belastung des informationsverarbeitenden Systems (processing load) als konvergierende Operation eingeführt wird. Schließlich werden Ansätze zur Messung der Geschwindigkeit der Informationsverarbeitung unter Maskierungsbedingungen referiert.

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Preparation of this report was facilitated by International Postdoctoral Research Fellowship No. F05-TW-1794 from the Public Health Service, National Institutes of Health, Bethesda, Md., USA. The helpful remarks of Dr. A. O. Dick are appreciated.     

Integration,interruption and processing rate in visual backward masking

Summary In order to decide between the integration and the interruption theory of backward masking, an experiment is conducted where a cue stimulus preceding the test stimulus by various intervals requires either identification of one test stimulus item (partial report) or recall of the whole test stimulus (full report). In addition, the test stimulus-masking stimulus agynchrony and the luminance of the masking stimulus are varied. When identification accuracy is plotted as a function of cue stimulus-test stimulus interval, the partial-report data can be broken down in two segments: an asymptotic value for long (greater than 500 msec) and a region of decreasing accuracy for short cue stimulus-test stimulus intervals. The asymptotic value depends on the test stimulus-masking stimulus asynchrony and the luminance of the masking stimulus; however, the decrease of accuracy is not affected by these parameters when the scores are normalized with respect to upper and lower limits of performance. Full-report performance shows a uniform decrease across the whole range of cue stimulus-test stimulus intervals. The manner in which asymptotic values depend on the test stimulus-masking stimulus asynchrony and on masking stimulus luminance is taken as evidence of a two-factor theory of backward masking proposed in a previous paper (Scheerer, 1973). But the data on decrease of accuracy require a revision of this theory: under certain conditions, test stimulus degradation may be compatible with an interruption theory. The different temporal course of partial and full report accuracy is used to distinguish between a peripheral (eye movement-mediated) and a central component in critical item selection.

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Zusammenfassung Zur Entscheidung zwischen der Unterbrechungs- und der Integrationstheorie der visuellen Maskierung wird ein Experiment durchgeführt, in dem ein in verschiedenen Abständen vor dem maskierten Testreiz dargebotener Indikatorreiz entweder zur selektiven Identifikation eines Testreizelements (Teilbericht) oder zur Reproduktion des gesamten Testreizes (Gesamtbericht) auffordert. Außerdem werden das Testreiz-Maskierreizintervall und die Leuchtdichte des Maskierreizes variiert. Wenn die Identifikationsgenauigkeit als Funktion des Indikator-Testreizintervalles aufgetragen wird, zerfallen die Teilberichtskurven in einen asymptotischen Wert für lange (größer als 500 msec) und in einen Bereich abfallender Genauigkeit für kurze Indikator-Testreizintervalle. Der asymptotische Wert hängt vom Testreiz-Maskierreizintervall und von der Leuchtdichte des Maskierreizes ab; im Bereich abfallender Genauigkeit sind die Kurven von diesen Parametern unabhängig, wenn sie hinsichtlich oberer und unterer Grenzwerte der Genauigkeit normalisiert werden. Die Gesamtberichtskurven zeigen einen gleichmäßigen Genauigkeitsabfall über den gesamten Bereich von Indikator-Testreizintervallen. Die Abhängigkeit des asymptotischen Werts vom Testreiz-Maskierreizintervall und von der Maskierreiz-Leuchtdichte wird als Hinweis auf die Gültigkeit der im Literaturbericht (Scheerer, 1973) formulierten Zwei-Faktorentheorie der visuellen Maskierung interpretiert. Jedoch erfordern die Befunde zum Abfall der Identiflkationsleistung eine Revision dieses Konzepts; unter bestimmten Bedingungen kann eine unterbrechende Wirkung des Maskierreizes zu einer Qualitätsminderung des Testreiz-Äquivalents führen. Aus dem unterschiedlichen Verlauf von Teilbericht und Gesamtbericht wird geschlossen, daß die Selektion eines Testreizelements in einen peripheren (durch Fixationsänderung vermittelten) und in einen zentralen Anteil zerlegt werden kann.

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Preparation of this report was facilitated by International Postdoctoral Fellowship No. F05-TW-1794 from the Public Health Service, National Institutes of Health, Bethesda, Md., USA, and by Grant NIMH MH-10753 to Dr. Ralph N. Haber.     

Backward masking,disinhibition, and hypothesized neural networks

Backward masking, metacontrast, and disinhibition can be obtained under a variety of conditions. The mechanisms that underlie each depend, of course, upon the particular conditions responsible for the effects. Theoretical expositions seeking to explain phenomena produced by small brief concentric disks of light in the same terms as those necessary to explain effects produced by large displaced complex patterns of light are likely to be wrong.     

Backward masking, the suffix effect, and preperceptual storage

This article considers the use of auditory backward recognition masking (ABRM) and stimulus suffix experiments as indexes of preperceptual auditory storage. In the first part of the article, two ABRM experiments that failed to demonstrate a mask disinhibition effect found previously in stimulus suffix experiments are reported. The failure to demonstrate mask disinhibition is inconsistent with an explanation of ABRM in terms of lateral inhibition. In the second part of the article, evidence is presented to support the conclusion that the suffix effect involves the contributions of later processing stages and does not provide an uncontaminated index of preperceptual storage. In contrast, it is claimed that ABRM experiments provide the most direct index of the temporal course of perceptual recognition. Partial-report tasks and other paradigms are also evaluated in terms of their contributions to an understanding of preperceptual auditory storage. Differences between interruption and integration masking are discussed along with the role of preperceptual auditory storage in speech perception.     

Backward masking: evidence of reduced subcortical amygdala engagement in autism

Recent data suggest that subthreshold presentation of emotional information is relayed to the amygdala along subcortical pathways. We examined the effect of backward masked neutral and anxious faces on the social decisions of a group of high functioning children with autism ages 7-13 years and matched controls. Participants were asked to select the friendliest of two faces, one of which was associated with the subthreshold (33 ms) presentation of an anxious face (A/N) and the other a subthreshold neutral face (N/N). Neutral paired faces were selected more often than A/N paired faces by both groups. However, children with autism selected significantly fewer N/N stimuli and more A/N stimuli than controls. These results suggest that the social choices of children with autism were influenced less by emotional information presented subconsciously and suggest a subcortical contribution to the social/emotional processing deficits observed in autism.     

Backward masking of lateralized faces by noise, pattern, and spatial frequency

Experiments 1 and 2 measured the critical interstimulus interval at which a face presented to the right or left visual field escaped a trailing noise, pattern, or spatial-frequency mask. The function relating target duration to critical ISI was multiplicative in the noise and spatial-frequency condition, but additive at longer durations in the pattern mask condition. An advantage of about 8 msec for the left visual field and 2 msec for the right field was found in the pattern and spatial-frequency masking condition, respectively. No consistent visual field differences were found in the noise mask condition. Taken together, these results suggest that hemispheric difference in face recognition are either absent or inconsistent at early, peripheral, energy-sensitive stages of processing, but emerge strongly at higher order central stages. The results also suggest that the left and right hemispheres are not differentially sensitive to the output of high- and low-spatial-frequency channels, respectively. If it is assumed that the central face processor is functionally localized to the right hemisphere, one can infer from these results that interhemispheric transmission time is not greater than 8 msec, and the output of sensory analysis and/or relational features are transferred across the interhemispheric commissures.     

Backward and forward masking in the perception of cutaneous stimuli

Masking of the perception of an electrical test stimulus by a mechanical shock was studied in six Ss. Forward and backward masking were observed in all Ss, the former being of longer duration. Duration of the masking effects is inversely related to the intensity of the test stimulus. Masking effects may be preceded and followed by perceptual facilitation. The masking effects may be responsible for the alterations in the perception of a somaesthetic stimulus before and during movement of the stimulated area.     

The speed of visual processing in children and adults: Effects of backward and forward masking

Children, 4-5 and 9-10 years old, and college-age adults were tested on two visual masking tasks. The first task required the Ss to identify whether a tachistoscopically presented bar was horizontal or vertical The second task, also using tachistoscopic presentation of stimuli, required Ss to locate a horizontal (or vertical) bar in a matrix of vertical (or horizontal) bars. In both tasks, backward masking produced greater disruption than did forward masking, and the amount of disruption induced by both backward and forward masking decreased as age increased. An Age by Masking Condition interaction was found only in the location task and reflected a much greater difference between backward- and forward-masking conditions for the youngest group than for the older groups. On the basis of these findings and other considerations, it was concluded that only in the location task, which presumably required visual search, was the speed of visual processing slower in the younger group.     

Wisconsin Card Sorting in adolescents: analysis of performance, response times and heart rate

Forty-nine adolescents performed the Wisconsin Card Sorting Test (WCST). A main PCA component of WCST performance was identified as 'efficiency of reasoning'. This factor was related to feedback processing. From the WCST, a perseveration score can be derived. Perseveration is the continued application of a rule, after it has been disconfirmed. We compared more and less perseverating subjects in relation to stimulus-response (SR) time, feedback inspection time and cardiac acceleration and deceleration. Less perseverating subjects responded faster, and had longer and more adaptive inspection times of error feedback. We examined the switch from rule application to rule search, and the difference between correct and error responses. A transient cardiac deceleration at the initiation of rule search was interpreted as a change in supervisory attention. An error-related deceleration to negative feedback was interpreted as a disturbance of higher control processing. Previous trial feedback influenced current processing time, feedback inspection time, and the cardiac acceleration and deceleration responses.