Repetition blindness for rotated objects.

Repetition blindness (RB) is the finding that observers often miss the repetition of an item within a rapid stream of words or objects. Recent studies have shown that RB for objects is largely unaffected by variations in viewpoint between the repeated items. In 5 experiments, we tested RB under different axes of rotation, with different types of stimuli (line drawings and shaded images, intact and split), using both novel and familiar objects. Although RB was largely viewpoint invariant, in most experiments, RB was reduced for small (0°) and large (180°) viewpoint differences relative to intermediate rotations. However, these deviations from invariance were eliminated when object images were split, breaking the holistic coherence of the object. These findings suggest that RB is due mainly to the activation of object representations from local diagnostic features, but can be modulated by priming on the basis of view similarity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Forward and backward repetition blindness in speed and accuracy.

Repetition blindness (RB) was investigated in a new paradigm in which effects could stem from items preceding or following a target. Speeded-response tasks were used in which 3 critical items (C1, C2, and C3) were sequentially presented on each trial. In Experiments 1 and 2, participants were asked to judge whether C2 (the target) was present on each trial. Forward RB was examined in Experiment 1 via manipulation of whether C1 and C2 were repeated and backward RB was probed in Experiment 2 via manipulation of whether C2 and C3 were repeated. RB was successfully demonstrated in both experiments: Target presence judgments were slower and less accurate with repeated conditions than with unrepeated conditions. Experiment 3 involved a semantic categorization task in which participants had to judge whether C2 was a letter or a digit. Manipulating forward and backward repetition produced reliable effects on both reaction times and accuracy. The results are consistent with the idea that RB is due to failure in token individualization rather than type refractory problems or failure in memory retrieval. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Repetition blindness for words yet repetition advantage for nonwords.

Accuracy of report of words in a rapidly presented sequence is reduced if 1 word is a repetition of a previous word. This is repetition blindness. If, however, the items are pronounceable nonwords, or pseudohomophones, repetition improves recall. A repetition advantage for nonwords also occurs when subjects merely count the items or when the item between the critical nonwords is a familiar word. Familiarizing subjects with the nonwords improved the level of recall but did not affect the repetition advantage. These results are considered in relation to token individuation and other accounts of repetition blindness. The findings suggest that for identical linguistic stimuli the types bound to episodic memory tokens that are vulnerable to repetition blindness are lexical units. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial repetition blindness for colour and shape.

The authors investigated three experiments on repetition blindness for briefly-presented masked displays containing only two coloured letters (one on either side of fixation). In Experiment 1, a single coloured letter (or nothing) was displayed on each side of fixation. Experiment 2 used a task in which subjects had to attend to Cl but not report it. They were either asked to report i) the colour of C2 if Cl was coloured, but the letter of C2 if Cl was white, or ii) the letter of C2 if Cl was a letter but the colour of c2 if cl was a nonletter symbol. RB was found for the features of the reported dimension, showing that attention to an item is sufficient to produce RB even if that item is not itself reported. And, in experiment 3, subjects reported either the colour of cl and the letter of C2 or vice versa, a task which required them to switch attended dimensions between Cl and C2. It is a question for future research whether RH simply requires prior attention to an object containing the repeated feature, or prior attention to the actual repeated feature itself. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Now you see it, now you don't: Repetition blindness for nonwords.

Repetition blindness (RB) for nonwords has been found in some studies, but not in others. The authors propose that the discrepancy in results is fueled by participant strategy; specifically, when rapid serial visual presentation lists are short and participants are explicitly informed that some trials will contain repetitions, participants are able to use partial orthographic information to correctly guess repetitions on repetition trials while avoiding spurious repetition reports on control trials. The authors first replicated V. Coltheart and R. Langdon's (2003) finding of RB for words but repetition advantage for nonwords (Experiment 1). When all participants were encouraged to utilize partial information in a same/different matching task along with an identification task, a repetition advantage was observed for both words and nonwords (Experiment 2). When guessing of repetitions was made detectable by including non-identical but orthographically similar items in the experiments, the repetition advantage disappeared; instead, RB was found for both words and nonwords (Experiments 3 and 4). Finally, when experiments did not contain any identical items, participants almost never reported repetitions, and reliable RB was found for orthographically similar words and nonwords (Experiments 5 and 6). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Repetition blindness has a perceptual locus: Evidence from online processing of targets in RSVP streams.

Four experiments tested whether repetition blindness (RB; reduced accuracy reporting repetitions of briefly displayed items) is a perceptual or a memory-recall phenomenon. RB was measured in rapid serial visual presentation (RSVP) streams, with the task altered to reduce memory demands. In Experiment 1 only the number of targets (1 vs. 2) was reported, eliminating the need to remember target identities. Experiment 2 segregated repeated and nonrepeated targets into separate blocks to reduce bias against repeated targets. Experiments 3 and 4 required immediate "online" buttonpress responses to targets as they occurred. All 4 experiments showed very strong RB. Furthermore, the online response data showed clearly that the 2nd of the repeated targets is the one missed. The present results show that in the RSVP paradigm, RB occurs online during initial stimulus encoding and decision making. The authors argue that RB is indeed a perceptual phenomenon. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sentence context, word recognition, and repetition blindness.

When the sentence She ran her best time yet in the rice last week is displayed using rapid serial visual presentation, viewers sometimes misread rice as race (M. C. Potter, A. Moryadas,1. Abrams, & A. Noel, 1993). Seven experiments combined misreading and repetition blindness (RB) paradigms to determine whether misreading of a word because of biasing sentence context represents a genuine perceptual effect. In Experiments 1-4, misreading a word either caused or prevented RB for a downstream word, depending on whether orthographic similarity was increased or decreased. Additional experiments examined temporal parameters of misreading RB and tested the hypothesis that RB results from reconstructive memory processes. Results suggest that the effect of prior context occurs during perception. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Repetition Blindness in Rapid Lists: Activation and Inhibition Versus Construction and Attribution.

The authors examine the repetition blindness effect--the failure to report one of the occurrences of a word presented twice in a rapid list. This phenomenon has been ascribed to inhibitory processes that prevent immediate tokenization of the 2nd occurrence of a repeated word. The authors present several kinds of evidence against that account, including observations that repetition blindness (a) does not occur when repetitions are not embedded in a list of familiar orthographic units, (b) is alleviated by precuing the subject with the identity of the word that may repeat within a rapid list, and (c) can be caused by cues presented after the list, when the opportunity for inhibition has passed. It is proposed that repetition blindness can better be understood through the principles of construction and attribution. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of lexicality and distinctiveness on repetition blindness.

The repetition blindness (RB) paradigm developed by K. M. Arnell and P. Jolic?ur (1997) was used to examine effects of lexicality (word vs. nonword target pairs) and target distinctiveness on RB. Distinctiveness was manipulated by having both targets (Experiments 1 and 2) or only the first target (Experiment 3) brighter than nontarget items. All 3 experiments demonstrated strong RB for word targets but no RB for nonword targets. This confirms that RB depends on pre-existing memory representations. In fact, there was repetition facilitation for nonwords in Experiments 2 and 3. These experiments also demonstrated that RB is reduced when targets are distinctive. This finding is better understood in terms of RB as a failure of memory rather than as a failure of perception. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dissociating emotion-induced blindness and hypervision.

Previous findings suggest that emotional stimuli sometimes improve (emotion-induced hypervision) and sometimes impair (emotion-induced blindness) the visual perception of subsequent neutral stimuli. We hypothesized that these differential carryover effects might be due to 2 distinct emotional influences in visual processing. On the one hand, emotional stimuli trigger a general enhancement in the efficiency of visual processing that can carry over onto other stimuli. On the other hand, emotional stimuli benefit from a stimulus-specific enhancement in later attentional processing at the expense of competing visual stimuli. We investigated whether detrimental (blindness) and beneficial (hypervision) carryover effects of emotion in perception can be dissociated within a single experimental paradigm. In 2 experiments, we manipulated the temporal competition for attention between an emotional cue word and a subsequent neutral target word by varying cue–target interstimulus interval (ISI) and cue visibility. Interestingly, emotional cues impaired target identification at short ISIs but improved target identification when competition was diminished by either increasing ISI or reducing cue visibility, suggesting that emotional significance of stimuli can improve and impair visual performance through distinct perceptual mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of perceptual load on attention-induced motion blindness: The efficiency of selective inhibition.

Recent visual marking studies have shown that the carry-over of distractor inhibition can impair the ability of singletons to capture attention if the singleton and distractors share features. The current study extends this finding to first-order motion targets and distractors, clearly separated in time by a visual cue (the letter X). Target motion discrimination was significantly impaired, a result attributed to the carry-over of distractor inhibition. Increasing the difficulty of cue detection increased the motion target impairment, as distractor inhibition is thought to increase under demanding (high load) conditions in order to maximize selection efficiency. The apparent conflict with studies reporting reduced distractor inhibition under high load conditions was resolved by distinguishing between the effects of "cognitive" and "perceptual" load. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Reorientation in a Two-Dimensional Environment: I. Do Adults Encode the Featural and Geometric Properties of a Two-Dimensional Schematic of a Room?

Adults searched for a goal in images of a rectangular environment. The goal's position was constant relative to featural and geometric cues, but the absolute position changed across trials. Participants easily learned to use the featural cues to find the target, but learning to use only geometric information was difficult. Transformation tests revealed that participants used the color and shape of distinct features to encode the goal's position. When the features at the correct and geometrically equivalent corners were removed, participants could use distant features to locate the goal. Accuracy remained above chance when a single distant feature was present, but the feature farthest from the goal yielded lower accuracy than one closer. Participants trained with features spontaneously encoded the geometric information. However, this representation did not withstand orientation transformations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intrahemispherical activation, visuomotor transmission, and the Simon effect: Comment on Wascher et al. (2001).

On the basis of 3 experiments, E. Wascher, U. Schatz, T. Kuder, and R. Verleger (2001; see record 2001-06699-017) concluded, "The variety of tasks subsumed under the term Simon effect turned out to be heterogeneous" (p. 749). This comment critically evaluates the validity of their conclusion by considering their hypotheses, methodology, specific conclusions, and proposed broader implications. Although the Simon effect is a behavioral phenomenon, E. Wascher et al. relied heavily on physiology in hypothesis generation, methodology, and interpretation of results. Moreover, methodological differences from most previous studies, combined with limited statistical support, nonreplication of previously reported behavioral phenomena, inconsistencies in results across experiments, and evidence against a contribution of intrahemispherical activation by visuomotor pathways, strongly suggest that their conclusion should be viewed with caution. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual marking and change blindness: Moving occluders and transient masks neutralize shape changes to ignored objects.

Visual search efficiency improves by presenting (previewing) one set of distractors before the target and remaining distractor items (D. G. Watson & G. W. Humphreys, 1997). Previous work has shown that this preview benefit is abolished if the old items change their shape when the new items are added (e.g., D. G. Watson & G. W. Humphreys, 2002). Here we present 5 experiments that examined whether such object changes are still effective in recapturing attention if the changes occur while the previewed objects are occluded or masked. Overall, the findings suggest that masking transients are effective in preventing both object changes and the presentation of new objects from capturing attention in time-based visual search conditions. The findings are discussed in relation to theories of change blindness, new object capture, and the ecological properties of time-based visual selection. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prototypes and particulars: Geometric and experience-dependent spatial categories.

People use geometric cues to form spatial categories. This study investigated whether people also use the spatial distribution of exemplars. Adults pointed to remembered locations on a tabletop. In Experiment 1, a target was placed in each geometric category, and the location of targets was varied. Adults' responses were biased away from a midline category boundary toward geometric prototypes located at the centers of left and right categories. Experiment 2 showed that prototype effects were not influenced by cross-category interactions. In Experiment 3, subsets of targets were positioned at different locations within each category. When prototype effects were removed, there was a bias toward the center of the exemplar distribution, suggesting that common categorization processes operate across spatial and object domains. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Validity and boundary conditions of automatic response activation in the Simon task.

Three experiments were conducted to determine whether spatial stimulus-response compatibility effects are caused by automatic response activation by stimulus properties or by interference between codes during translation of stimulus into response coordinates. The main evidence against activation has been that in a Simon task with hands crossed, responses are faster at the response location ipsilateral to the stimulus though manipulated by the hand contralateral to the stimulus. The experiments were conducted with hands in standard and in crossed positions and electroencephalogram measures showed coactivation of the motor cortex induced by stimulus position primarily during standard hand positions with visual stimuli. Only in this condition did the Simon effect decay with longer response times. The visual Simon effect appeared to be due to specific mechanisms of visuomotor information transmission that are not responsible for the effects obtained with crossed hands or auditory stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Masked Repetition and Phonological Priming Within and Across Modalities.

Lexical decision latencies to word targets presented either visually or auditorily were faster when directly preceded by a briefly presented (53-ms) pattern-masked visual prime that was the same word as the target (repetition primes), compared with different word primes. Primes that were pseudohomophones of target words did not significantly influence target processing compared with unrelated primes (Experiments 1-2) but did produce robust priming effects with slightly longer prime exposures (67 ms) in Experiment 3. Like repetition priming, these pseudohomophone priming effects did not interact with target modality. Experiments 4 and 5 replicated this general pattern of effects while introducing a different measure of prime visibility and an orthographic priming condition. Results are interpreted within the framework of a bimodal interactive activation model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Role of Melodic and Temporal Cues in Perceiving Musical Meter.

A number of different cues allow listeners to perceive musical meter. Three experiments examined effects of melodic and temporal accents on perceived meter in excerpts from folk songs scored in 6/8 or 3/4 meter. Participants matched excerpts with 1 of 2 metrical drum accompaniments. Melodic accents included contour change, melodic leaps, registral extreme, melodic repetition, and harmonic rhythm. Two experiments with isochronous melodies showed that contour change and melodic repetition predicted judgments. For longer melodies in the 2nd experiment, variables predicted judgments best at the beginning of excerpts. The final experiment, with rhythmically varied melodies, showed that temporal accents, tempo, and contour change were the strongest predictors of meter. The authors' findings suggest that listeners combine multiple melodic and temporal features to perceive musical meter. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Location serves as a conditional cue when harp seals (Pagophilus groenlandicus) solve object discrimination reversal problems.

We examined the capacity of harp seals (Pagophilus groenlandicus) to use spatial context (i.e., their tank) as a conditional cue to solve a two-choice visual discrimination reversal task. Seals were trained to touch one of two 3D objects. Two of four seals experienced a context shift that coincided with each of five reversals in the reward value of the two stimuli (i.e., a reversal of S+ and S-); these seals solved the six discriminations in significantly fewer trials than did seals that did not experience a context shift with the contingency reversal. Thus, harp seals use contextual cues when encoding information. The findings are discussed in terms of harp seals' adaptations to the pack-ice environment, the constraints of the learning tasks, and the nature of the subjects that were raised in captivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Allocentric Versus Egocentric Spatial Memory After Unilateral Temporal Lobectomy in Humans.

Thirty patients who had undergone either a right or left unilateral temporal lobectomy (14 RTL; 16 LTL) and 16 control participants were tested on a computerized human analogue of the Morris Water Maze. The procedure was designed to compare allocentric and egocentric spatial memory. In the allocentric condition, participants searched for a target location on the screen, guided by object cues. Between trials, participants had to walk around the screen, which disrupted egocentric memory representation. In the egocentric condition, participants remained in the same position, but the object cues were shifted between searches to prevent them from using allocentric memory. Only the RTL group was impaired on the allocentric condition, and neither the LTL nor RTL group was impaired on additional tests of spatial working memory or spatial manipulation. The results support the notion that the right anterior temporal lobe stores long-term allocentric spatial memories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)