Gestalt grouping and common onset masking

A four-dot mask that surrounds and is presented simultaneously with a briefly presented target will reduce a person's ability to identity that target if the mask persists beyond target offset and attention is divided (Enns & Di Lollo, 1997, 2000). This masking effect, referred to as common onset masking, reflects reentrant processing in the visual system and can best be explained with a theory of object substitution (Di Lollo, Enns, & Rensink, 2000). In the present experiments, we investigated whether Gestalt grouping variables would influence the strength of common onset masking. The results indicated that (1) masking was impervious to grouping by form, similarity of color, position, luminance polarity, and common region and (2) masking increased with the number of elements in the masking display.     

Masking by object substitution: dissociation of masking and cuing effects

In a newly discovered form of visual masking, a target stimulus is masked by 4 flanking dots if their offset is delayed relative to the target (V. Di Lollo, J. T. Enns, & R. A. Rensink, 2000). In Di Lollo et al. (2000), the dot pattern also cued the relevant target and therefore required deliberate attention. In the present Experiments 2-6, a central arrow cued 1 of 2 letters for an E/F discrimination, with dots flanking both letters. Masking was reduced compared with the mask-cue procedure but was still robust. Delayed-offset dots flanking the nontarget also impaired performance, indicating competition for attention. Masking was unaffected by brightness of the dots relative to the target. Masking was attenuated not only by precuing attention to the target location but also by preview of an uninformative dot mask. Theories of masking by object substitution must therefore accommodate the prior context into which the target stimulus is introduced.     

Asymmetric object substitution masking

Object substitution masking occurs when a lateral mask persists beyond the duration of a target, reflecting reentrant processes in vision (V. Di Lollo, J. Enns, & R. Rensink, 2000). The authors studied whether substitution masking is location specific and whether it is symmetric around the target. A brief circular display of letters was presented along with a mask that designated the target. The mask was centered on the target or 1.1 degrees to the central or to the peripheral side. Substitution masking was found even when the target and the mask were at different locations. It was asymmetric and stronger when the mask was to the peripheral side of the target than to the central side. Asymmetric substitution was observed using various masks. It could not be explained by retina acuity gradients and was not attenuated by focused attention. The authors propose that target selection triggers an asymmetric inhibitory surround that is stronger toward the central side of the target.     

Both exogenous and endogenous target salience manipulations support resource depletion accounts of the attentional blink: A reply to Olivers, Spalek, Kawahara, and Di Lollo (2009)

Input control theories of the attentional blink (AB) suggest that this deficit results from impaired attentional selection caused by the post-Target 1 (T1) distractor (Di Lollo, Kawahara, Ghorashi, & Enns, 2005; Olivers, van der Stigchel, & Hulleman, 2007). Accordingly, these theories predict that there should be no AB when no distractors intervene between the targets. Contrary to these hypotheses, Dux, Asplund, and Marois (2008) observed an AB (T3 deficit) when three targets, from the same attentional set, were presented successively in a rapid stream of distractors, if subjects increased the resources they devoted to T1 processing. This result is consistent with resource depletion accounts of the AB. However, Olivers, Spalek, Kawahara, and Di Lollo (2009) argue that Dux et al.’s results can be better explained by the relationship between T1 and T2, and by target discriminability effects, rather than by the relationship between T1 and T3. Here, we find that manipulating the resources subjects devote to T1, either exogenously (target perceptual salience) or endogenously (target task relevance), affects T3 performance, even when T2 and target discriminability differences are controlled for. These results support Dux et al.’s conclusion that T1 resource depletion underlies the AB.     

Accounting for belief bias in a mental model framework: comment on Klauer, Musch, and Naumer (2000)

K. C. Klauer, J. Musch, and B. Naumer (2000; see record 2000-02818-008) presented a general multinomial model of belief bias effects in syllogistic reasoning. They claimed to map a particular mental model account of belief bias (J. V. Oakhill, P. N. Johnson-Laird, & A. Garnham, 1989; see record 1989-38845-001)) onto this model and to show empirically that it is incorrect. The authors argue that this mental model account does not map onto the multinomial model and that it can account for the data presented by Klauer et al. (Experiments 1-4). The authors further argue that additional data Klauer et al. presented in support of a new model of their own (Experiments 5-8) are explained by this mental model account. The mental model account is, therefore, refuted neither by Klauer et al.'s theoretical analysis nor by any of the results they presented. Furthermore, the account can accommodate more recent findings on belief bias in a more satisfactory way than can alternative models that have been proposed.     

What is being masked in object substitution masking?

Object substitution masking (OSM) is said to occur when a perceptual object is hypothesized that is mismatched by subsequent sensory evidence, leading to a new hypothesized object being substituted for the first. For example, when a brief target is accompanied by a longer lasting display of nonoverlapping mask elements, reporting of target features may be impaired. J. T. Enns and V. Di Lollo (2000) considered it an outstanding question whether OSM masks some or all aspects of a target. The authors report three experiments demonstrating that OSM can selectively affect target features. Participants may be able to detect a target while being unable to report other aspects of it or to report the color but not the orientation of a target (or vice versa). We discuss these findings in relation to two other visual phenomena.     

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.     

Stimulus duration may affect partial report performance

Townsend, and Di Lollo and Moscovitch investigated the retention of item information in nearly identical variations of the partial report task. Whereas Townsend found a slight decrement in performance as the interval increased, Di Lollo and Moscovitch found a substantial increment. An experimental study of procedural differences that may have led to this discrepancy is reported. The results suggest that stimulus duration may have been responsible: Di Lollo and Moscovitch used extremely short durations (2 ms), while Townsend used longer durations (50 ms). This difference in durations may be important when the stimulus array and the partial report probe occur in close temporal contiguity.     

Temporal overlap in the linguistic processing of successive words in reading: reply to Pollatsek, Reichle, and Rayner (2006a)

A. Pollatsek, E. D. Reichle, and K. Rayner argue that the critical findings in A. W. Inhoff, B. M. Eiter, and R. Radach are in general agreement with core assumptions of sequential attention shift models if additional assumptions and facts are considered. The current authors critically discuss the hypothesized time line of processing and indicate that the success of Pollatsek et al.'s simulation is predicated on a gross underestimation of the pretarget word's viewing duration in Inhoff et al. and that the actual data are difficult to reconcile with the strictly serial attention shift assumption. The authors also discuss attention shifting and saccade programming assumptions in the E-Z Reader model and conclude that these are not in harmony with research in related domains of study.     

Representational masking and the attentional blink

After successful detection of a target item within a stream of rapidly displayed visual stimuli, subsequent detection of an additional target is impaired for roughly 500 ms. This impairment is known as the “attentional blink” (AB). Previous studies have found that if either the first (Tl; Raymond, Shapiro, & Arnell, 1992) or second target (T2; Giesbrecht & Di Lollo, 1998) is not followed by a mask, the AB impairment is significantly reduced. Whereas low-level perceptual factors have been found to influence the efficacy of masking in the AB (e.g., Seiffert & Di Lollo, 1997), the current experiment used a higher level (representational) manipulation, i.e., repetition blindness to reduce the efficacy of target masking in the AB. These findings contribute to the growing literature suggesting that masking plays more than a perceptual role in the AB phenomenon.     

Effects of display luminance, stimulus meaningfulness, and probe duration on visible and schematic persistence

Partial report performance is conceived of as consisting of two independent sources of information: visible persistence and schematic persistence. Following the work of Di Lollo and Dixon (1988), these two sources of information were separated experimentally by varying interstimulus interval and stimulus onset asynchrony independently. In the present experiment we asked whether visible persistence and schematic persistence would be affected by display luminance, stimulus meaningfulness, or probe duration. The results were fit accurately by an extension of the Di Lollo and Dixon independent-decay model in which display luminance affected visible persistence but stimulus meaningfulness and probe duration affected neither form of persistence directly.     

The reconfiguration of task set has no effect on the efficiency of feature search

In this study, we investigated whether or not the reconfiguration of a set task could modulate the efficiency of feature search. In Experiment 1, target set size was manipulated. The results revealed that enumerating targets defined by color yields a much steeper slope when executed simultaneously with a discrimination task than when done singly. However, when distractor set size was manipulated, there was no significant difference in the efficiency of individualizing targets from distractors between the two task conditions, no matter whetherthe search was guided by bottom-up information (Experiment 2) or top-down information (Experiment 3). Drawing upon these results, the authors propose that (1) an additional task can impair the efficiency of enumeration, resulting in a steep slope of counting even when target set size is quite small, and (2) in feature search, the visual system first reconfigures the task set to match the input feature information and then detects the targets with an optimal efficiency, which does not support the theory proposed by Di Lollo, Kawahara, Zuvic, and Visser (2001; Di Lollo, Smilek, Kawahara, & Ghorashi, 2005).     

Endogenous cueing attenuates object substitution masking

Object substitution masking (OSM) is a form of visual masking in which a briefly presented target surrounded by four small dots is masked by the continuing presence of the four dots after target offset. A major parameter in the prediction of OSM is the time required for attention to be directed to the target following its onset. Object substitution theory (Di Lollo et al. in J Exp Psychol Gen 129:481–507, 2000) predicts that the sooner attention can be focused at the target’s location, the less masking will ensue. However, recently Luiga and Bachmann (Psychol Res 71:634–640, 2007) presented evidence that precueing of attention to the target location prior to target-plus-mask onset by means of a central (endogenous) arrow cue does not reduce OSM. When attention was cued exogenously, OSM was attenuated. Based on these results, Luiga and Bachmann argued that object substitution theory should be adapted by differentiating the ways of directing attention to the target location. The goal of the present study was to further examine the dissociation between the effects of endogenous and exogenous precueing on OSM. Contrary to Luiga and Bachmann, our results show that prior shifts of attention to the target location initiated by both exogenous and endogenous cues reduce OSM as predicted by object substitution theory and its computational model CMOS.     

Features versus redundancy: comments on Massaro, Venezky, and Taylor's "Orthographic regularity, positional frequency, and visual processing of letter strings"

Massaro, Venezky, and Taylor (1979) found only a modest effect of familiarity on letter search, apparently because they pitted pseudowords (rather than real words) against nonwords and used lowercase rather than uppercase letters. Precuing the target letter seemed to reduce the familiarity effect they found yet further, but this conclusion is clouded by the fact that reaction time data were compared with accuracy data. Because similarity between target and nontarget letters tended to have more of an effect when familiarity had less of an effect. Massaro et al. proposed a successive model, with features being detected in the first stage and orthographic structure being used in a second stage. However, a concurrent model, with a self-terminating race between lower and higher level processes, can account for the data just as well. Data from Massaro et al. and from Krueger decisively demonstrate that there is a familiarity effect based on sequential redundancy over and above any effect based on spatial redundancy (Mason 1975). The Massaro et al. data also indicate that the relative familiarity effect is constant across various age groups (Krueger, Keen & Rublevich, 1974).     

The validity and appropriateness of methods, analyses, and conclusions in Rind et al. (1998): A rebuttal of victimological critique from Ondersma et al. (2001) and Dallam et al. (2001).

The authors respond to 2 victimological critiques of their 1998 meta-analysis on child sexual abuse (CSA). S. J. Dallam et al. (2001) claimed that B. Rind, P. Tromovitch, and R. Bauserman (1998) committed numerous methodological and statistical errors, and often miscoded and misinterpreted data. The authors show all these claims to be invalid. To the contrary, they demonstrate frequent bias in Dallam et al.'s criticisms. S. J. Ondersma et al. (2001) claimed that Rind et al.'s study is part of a backlash against psychotherapists, that its suggestions regarding CSA definitions were extrascientific, and that the moral standard is needed to understand CSA scientifically. The authors show their suggestions to have been scientific and argue that it is Ondersma et al.'s issue-framing and moral standard that are extrascientific. This reply supports the original methods, analyses, recommendations, and conclusions of Rind et al.     

Relationship between visual binding, reentry and awareness

Visual feature binding has been suggested to depend on reentrant processing. We addressed the relationship between binding, reentry, and visual awareness by asking the participants to discriminate the color and orientation of a colored bar (presented either alone or simultaneously with a white distractor bar) and to report their phenomenal awareness of the target features. The success of reentry was manipulated with object substitution masking and backward masking. The results showed that late reentrant processes are necessary for successful binding but not for phenomenal awareness of the bound features. Binding errors were accompanied by phenomenal awareness of the misbound feature conjunctions, demonstrating that they were experienced as real properties of the stimuli (i.e., illusory conjunctions). Our results suggest that early preattentive binding and local recurrent processing enable features to reach phenomenal awareness, while later attention-related reentrant iterations modulate the way in which the features are bound and experienced in awareness.     

The role of visible persistence for perception of visual bilateral symmetry1

Abstract: Although the detection of visual bilateral symmetry has been claimed to be highly efficient, the possible involvement and function of visual memory in such efficient mechanisms has rarely been examined. We hypothesized that symmetry perception is rapid, as it can be achieved from rapidly decaying information of visible persistence. To test this hypothesis, we employed a temporal integration paradigm. A symmetric dot pattern was randomly divided into two asymmetric patterns and presented successively with a blank screen presented between patterns. Observers could detect symmetry when the two patterns were presented close in time (Experiment 1), indicating that observers perceived symmetry presumably utilizing visible persistence. In addition, the inverse‐intensity effect of visible persistence (Di Lollo & Bischof, 1995) was evident in our temporal integration task of symmetry (Experiment 2). The results of the current study clearly demonstrate that the detection of symmetry can be achieved based on the visible persistence. The large capacity and high spatial precision of visible persistence might be adequate for the rapid and spatially global encoding of visual symmetry.     

In Defense of Competition During Syntactic Ambiguity Resolution

In a recent series of publications (Traxler et al. J Mem Lang 39:558–92, 1998; Van Gompel et al. J Mem Lang 52:284–07, 2005; see also Van Gompel et al. (In: Kennedy, et al.(eds) Reading as a perceptual process, Oxford, Elsevier pp 621–48, 2000); Van Gompel et al. J Mem Lang 45:225–58, 2001) eye tracking data are reported showing that globally ambiguous (GA) sentences are read faster than locally ambiguous (LA) counterparts. They argue that these data rule out ‘constraint-based’models where syntactic and conceptual processors operate concurrently and syntactic ambiguity resolution is accomplished by competition. Such models predict the opposite pattern of reading times. However, this argument against competition is valid only in conjunction with two standard assumptions in current constraint-based models of sentence comprehension: (1) that syntactic competitions (e.g., Which is the best attachment site of the incoming constituent?) are pooled together with conceptual competitions (e.g., Which attachment site entails the most plausible meaning?), and (2) that the duration of a competition is a function of the overall (pooled) quality score obtained by each competitor. We argue that it is not necessary to abandon competition as a successful basis for explaining parsing phenomena and that the above-mentioned reading time data can be accounted for by a parallel-interactive model with conceptual and syntactic processors that do not pool their quality scores together. Within the individual linguistic modules, decision-making can very well be competition-based.     

Repetition effects in word and pseudoword identification: comment on Salasoo, Shiffrin, and Feustel

Two recent articles by Feustel, Shiffrin, and Salasoo (1983) and Salasoo, Shiffrin, and Feustel (1985) argue that word identification is based on episodic memory as well as semantic (or "permanent, abstract") memory. The earlier article argued for separate processing stages affected by repetition (episodic memory) and lexicality (semantic memory). To account for the new finding that number of repetitions interacts with lexicality, the later article invokes the same two types of memory, operating in parallel rather than serially. We argue that Salasoo et al.'s data are compatible with a wide variety of competing theories, including some that do not involve episodic memory at all. We question the relevance of a complex formal model shown by the authors to account for the main trends in the data, because it makes little use of key properties of episodic memory. Furthermore, we show that two variants of a less complex model inspired by logogen theory fit the data as well or better than the model of Salasoo et al., using fewer free parameters. We argue that what is needed is not an existence proof that one particular complex model can fit a body of data, but experimental manipulations that successfully discriminate between broad classes of competing theories.     

An attentional blink for sequentially presented targets: Evidence in favor of resource depletion accounts

Several accounts of the attentional blink (AB) have postulated that this dual-target deficit occurs because of limited-capacity attentional resources being devoted to processing the first target at the expense of the second (resource depletion accounts; e.g., Chun & Potter, 1995). Recent accounts have challenged this model (e.g., Di Lollo, Kawahara, Ghorashi, & Enns, 2005; Olivers, van der Stigchel, & Hulleman, 2007), proposing instead that the AB occurs because of subjects’ inability to maintain appropriate levels of attentional control when targets are separated by distractors. Accordingly, the AB is eliminated when three targets from the same attentional set are presented sequentially in a rapid serial visual presentation (RSVP) stream. However, under such conditions poorer identification of the first target is typically observed, hinting at a potential trade-off between the first and subsequent target performances. Consistent with this hypothesis, the present study shows that an AB is observed for successive targets from the same attentional set in an RSVP stream when the first target powerfully captures attention. These results suggest that resource depletion contributes significantly to the AB.