Method matters: Systematic effects of testing procedure on visual working memory sensitivity.

Visual working memory (WM) is traditionally considered a robust form of visual representation that survives changes in object motion, observer's position, and other visual transients. This article presents data that are inconsistent with the traditional view. We show that memory sensitivity is dramatically influenced by small variations in the testing procedure, supporting the idea that representations in visual WM are susceptible to interference from testing. In the study, participants were shown an array of colors to remember. After a short retention interval, memory for one of the items was tested with either a same–different task or a 2-alternative-forced-choice (2AFC) task. Memory sensitivity was much lower in the 2AFC task than in the same–different task. This difference was found regardless of encoding similarity or of whether visual WM required a fine or coarse memory resolution. The 2AFC disadvantage was reduced when participants were informed shortly before testing which item would be probed. The 2AFC disadvantage diminished in perceptual tasks and was not found in tasks probing visual long-term memory. These results support memory models that acknowledge the labile nature of visual WM and have implications for the format of visual WM and its assessment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On homogeneous retinal stimulation and the perception of depth.

A review of recent experiments showing that where the perception of voluminous fog does not occur consistently under conditions attempting homogeneity of visual stimulation, there are sources of inhomogeneity which can produce the impression of a surface. As homogeneity is approached, the volume experience becomes more reliable. A view of this phenomenon, other than Gibson's—which does not deal with it on the grounds of poor reliability—or Koffka's—which attributes it to the fundamental nature of the perceptual system, is presented. It is based on kinesthetic stimulation as a likely source of visual space anisotropy with respect to perceived distance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intertrial Temporal Contextual Cuing: Association Across Successive Visual Search Trials Guides Spatial Attention.

Contextual cuing refers to the facilitation of performance in visual search due to the repetition of the same displays. Whereas previous studies have focused on contextual cuing within single-search trials, this study tested whether 1 trial facilitates visual search of the next trial. Participants searched for a T among Ls. In the training phase, the spatial layout on trial N=1 was predictive of the target location on trial N. In the testing phase, the predictive value was removed. Results revealed an intertrial temporal contextual cuing effect: Search speed became progressively shorter in the training phase, but it significantly lengthened during testing. The authors conclude that the visual system is capable of retaining spatial contextual memory established earlier to facilitate perception. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recovery from object substitution masking induced by transient suppression of visual motion processing: A repetitive transcranial magnetic stimulation study.

Object substitution masking is a form of visual backward masking in which a briefly presented target is rendered invisible by a lingering mask that is too sparse to produce lower image-level interference. Recent studies suggested the importance of an updating process in a higher object-level representation, which should rely on the processing of visual motion, in this masking. Repetitive transcranial magnetic stimulation (rTMS) was used to investigate whether functional suppression of motion processing would selectively reduce substitution masking. rTMS-induced transient functional disruption of cortical area V5/MT+, which is important for motion analysis, or V1, which is reciprocally connected with V5/MT+, produced recovery from masking, whereas sham stimulation did not. Furthermore, masking remained undiminished following rTMS over the region 2 cm posterior to V5/MT+, ruling out nonspecific effects of real stimulation and confirming regional specificity of the rTMS effect. The results suggest that object continuity via the normal function of the visual motion processing system might in part contribute to this masking. The relation of these findings to the reentrant processing view of object substitution masking and other visual phenomena is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Flexible visual statistical learning: Transfer across space and time.

The environment contains considerable information that is distributed across space and time, and the visual system is remarkably sensitive to such information via the operation of visual statistical learning (VSL). Previous VSL studies have focused on establishing what kinds of statistical relationships can be learned but have not fully explored how this knowledge is then represented in the mind. These representations could faithfully reflect the details of the learning context, but they could also be generalized in various ways. This was studied by testing how VSL transfers across changes between learning and test, and the results revealed a substantial degree of generalization. Learning of statistically defined temporal sequences was expressed in static spatial configurations, and learning of statistically defined spatial configurations facilitated detection performance in temporal streams. Learning of temporal sequences even transferred to reversed temporal orders during test when accurate performance did not depend on order, per se. These types of transfer imply that VSL can result in flexible representations, which may in turn allow VSL to function in ever-changing natural environments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hyperspecificity in Visual Implicit Learning: Learning of Spatial Layout Is Contingent on Item Identity.

Humans conduct visual search faster when the same display is presented for a 2nd time, showing implicit learning of repeated displays. This study examines whether learning of a spatial layout transfers to other layouts that are occupied by items of new shapes or colors. The authors show that spatial context learning is sometimes contingent on item identity. For example, when the training session included some trials with black items and other trials with white items, learning of the spatial layout became specific to the trained color--no transfer was seen when items were in a new color during testing. However, when the training session included only trials in black (or white), learning transferred to displays with a new color. Similar results held when items changed shapes after training. The authors conclude that implicit visual learning is sensitive to trial context and that spatial context learning can be identity contingent. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automatic guidance of visual attention from verbal working memory.

Previous studies have shown that visual attention can be captured by stimuli matching the contents of working memory (WM). Here, the authors assessed the nature of the representation that mediates the guidance of visual attention from WM. Observers were presented with either verbal or visual primes (to hold in memory, Experiment 1; to verbalize, Experiment 2; or merely to attend, Experiment 3) and subsequently were required to search for a target among different distractors, each embedded within a colored shape. In half of the trials, an object in the search array matched the prime, but this object never contained the target. Despite this, search was impaired relative to a neutral baseline in which the prime and search displays did not match. An interesting finding is that verbal primes were effective in generating the effects, and verbalization of visual primes elicited similar effects to those elicited when primes were held in WM. However, the effects were absent when primes were only attended. The data suggest that there is automatic encoding into WM when items are verbalized and that verbal as well as visual WM can guide visual attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Discrimination of computer-graphic stimuli by mice: A method for the behavioral characterization of transgenic and gene-knockout models.

An automated method is described for the behavioral testing of mice in an apparatus that allows computer-graphic stimulus material to be presented. Mice responded to these stimuli by making a nose-poke toward a computer monitor that was equipped with a touchscreen attachment for detecting responses. It was found that C57BLJ/6 mice were able to solve single-pair visual discriminations as well as 3-pair concurrent visual discriminations. The finding that mice are capable of complex visual discriminations introduces the possibility of testing mice on nonspatial tasks that are similar to those used with rats, monkeys, and humans. Furthermore, the method seems particularly well suited to the comprehensive behavioral assessment of transgenic and gene-knockout models. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of controlled rearing on the development of stimulus-seeking behavior in rats.

Three experiments compared the performance of 272 differentially reared Long-Evans rats at 15–90 days of age in a situation in which the amount of self-exposure to various lighted displays was being measured. The kind of visual array preferred by these Ss was significantly influenced by both their ages and visual stimulation histories. Preference for light arrays involving features significantly increased in the case of light-reared and bias-reared Ss beginning at 60 days of age. At the same time, a preference for diffuse light stimulation emerged in the case of their dark-reared (DR) controls. Although the significant increase in light-seeking exhibited by all groups of Ss at 60 days of age was found to be unrelated to previous testing in the situation, the visual experience associated with repeated tests did "protect" DR Ss from the decline in light-seeking observed after prolonged visual deprivation. Potential species differences and the nature and specificity of these changes in visual behavior are further discussed with respect to the role of early experience in visual development. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Knowledge About the Probability of Change Affects Change Detection Performance.

The visual system continually selects some information for processing while bypassing the processing of other information, and as a consequence, participants often fail to notice large changes to visual stimuli. In the present studies, the authors investigated whether knowledge about the probability of particular changes occurring over time increased the likelihood that changes that were likely to occur in the real world (probable changes) would be detected. The results of two experiments showed that participants were more likely to detect probable changes. This occurred whether or not they were processing the scene in a meaningful manner or actively searching the scene for changes. Furthermore, participants were unable to accurately predict change detection performance for probable and improbable changes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporal integration between visual images and visual percepts.

Using a temporal integration task, subjects in 5 experiments were expected to combine information from temporally separated visual presentations. Evidence from these experiments indicated that perceptual information can be integrated with previously generated and currently maintained visual images to form a representation that contains information from each source. Properties and limitations of this integration process were also explored, including the time required to generated the image, the speed at which percepts were integrated with images, and the capacity of the representation. Implications for theories of visual processing and memory are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reflections on blindsight: Neuroimaging and behavioural explorations clarify a case of reversed localisation in the blind field of a patient with hemianopia.

Blindsight refers to residual visual abilities of patients with primary visual cortex lesions. Most of this research uses single case studies, most famously patient GY. We examined a patient (DC) after surgical resection of V1 who demonstrated robust but reversed blind field target localisation, mislocalising midline blind field targets to the periphery and vice versa. This pattern was reliable across multiple sessions and was not because of extraocular light scatter. We then used functional magnetic resonance imaging to examine neural responses to blind field motion stimuli with no evidence of motion-selective activation in DC's extrastriate cortex in the damaged hemisphere, in stark contrast to GY who showed robust bilateral activation in response to blind field stimuli. This suggests that DC's blind field performance may not represent true blindsight. Follow-up testing with the target—background contrast reversed (i.e., black targets/white background), eliminated DC's reversed localisation, strongly suggesting that she was employing an unusual decision criterion based on intraocular light scatter. DC's failure to demonstrate true blindsight may be related to the age at which she acquired her lesion—much later in life than GY. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of a new Army visual testing instrument.

A new device (Instrument B—an optical device to simulate the 20-foot distance of wall alleys) for testing photopic visual acuity was evaluated by comparison of test results with those obtained from the Standard Wall Chart Visual Acuity Examination (WC). Instrument B scores and WC scores correlated in the .90's, and test-retest reliabilities were also in the .90's. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual search for facial expressions of emotions: A comparison of dynamic and static faces.

A number of past studies have used the visual search paradigm to examine whether certain aspects of emotional faces are processed preattentively and can thus be used to guide attention. All these studies presented static depictions of facial prototypes. Emotional expressions conveyed by the movement patterns of the face have never been examined for their preattentive effect. The present study presented for the first time dynamic facial expressions in a visual search paradigm. Experiment 1 revealed efficient search for a dynamic angry face among dynamic friendly faces, but inefficient search in a control condition with static faces. Experiments 2 to 4 suggested that this pattern of results is due to a stronger movement signal in the angry than in the friendly face: No (strong) advantage of dynamic over static faces is revealed when the degree of movement is controlled. These results show that dynamic information can be efficiently utilized in visual search for facial expressions. However, these results do not generally support the hypothesis that emotion-specific movement patterns are always preattentively discriminated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What Kind of Memory Supports Visual Marking?

In visual search tasks, if a set of items is presented for 1 s before another set of new items (containing the target) is added, search can be restricted to the new set. The process that eliminates old items from search is visual marking. This study investigates the kind of memory that distinguishes the old items from the new items during search. Using an accuracy paradigm in which perfect marking results in 100% accuracy and lack of marking results in near chance performance, the authors show that search can be restricted to new items not by visual short-term memory (VSTM) of old locations but by a limited capacity and slow-decaying VSTM of new locations and a high capacity and fast-decaying memory for asynchrony. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"A core knowledge architecture of visual working memory": Correction to Wood (2011).

Reports an error in "A core knowledge architecture of visual working memory" by Justin N. Wood (Journal of Experimental Psychology: Human Perception and Performance, 2011[Apr], Vol 37[2], 357-381). The supplemental materials DOI is incorrect. The correct DOI for the supplemental materials is provided in the erratum. (The following abstract of the original article appeared in record 2011-06411-002.) Visual working memory (VWM) is widely thought to contain specialized buffers for retaining spatial and object information: a 'spatial-object architecture.' However, studies of adults, infants, and nonhuman animals show that visual cognition builds on core knowledge systems that retain more specialized representations: (1) spatiotemporal representations for object tracking, (2) object identity representations for object recognition, and (3) view-dependent snapshots for place recognition. In principle, these core knowledge systems may retain information separately from one another. Consistent with this hypothesis, this study provides evidence that these three types of information are subject to independent working memory storage limits. These results, combined with those from previous studies, indicate that VWM contains three specialized buffers for retaining spatiotemporal information, object identity information, and snapshot information. Thus, VWM buffers parallel core knowledge systems. This 'core knowledge architecture' links the study of visual working memory to the study of the biological foundations of visual cognition. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The Automaticity of Visual Statistical Learning.

The visual environment contains massive amounts of information involving the relations between objects in space and time, and recent studies of visual statistical learning (VSL) have suggested that this information can be automatically extracted by the visual system. The experiments reported in this article explore the automaticity of VSL in several ways, using both explicit familiarity and implicit response-time measures. The results demonstrate that (a) the input to VSL is gated by selective attention, (b) VSL is nevertheless an implicit process because it operates during a cover task and without awareness of the underlying statistical patterns, and (c) VSL constructs abstracted representations that are then invariant to changes in extraneous surface features. These results fuel the conclusion that VSL both is and is not automatic: It requires attention to select the relevant population of stimuli, but the resulting learning then occurs without intent or awareness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inverse target- and cue-priming effects of masked stimuli.

The processing of a visual target that follows a briefly presented prime stimulus can be facilitated if prime and target stimuli are similar. In contrast to these positive priming effects, inverse priming effects (or negative compatibility effects) have been found when a mask follows prime stimuli before the target stimulus is presented: Responses are facilitated after dissimilar primes. Previous studies on inverse priming effects examined target-priming effects, which arise when the prime and the target stimuli share features that are critical for the response decision. In contrast, 3 experiments of the present study demonstrate inverse priming effects in a nonmotor cue-priming paradigm. Inverse cue-priming effects exhibited time courses comparable to inverse target-priming effects. Results suggest that inverse priming effects do not arise from specific processes of the response system but follow from operations that are more general. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Species of redundancy in visual target detection.

We report a series of investigations into the effects of common names, physical identity, and physical similarity on visual detection time. The effect of these factors on the capacity of the system processing the signals was also examined. We used a redundant targets design with separate testing of the target-distractor (single target), target-target (redundant targets), and distractor-distractor (no targets) displays. When a target and a distractor share names, detection of the target is slower than it is in a situation in which the two do not go by a common name. Nevertheless, the gain reaped by redundant targets in this situation is larger and signal processing is of increased capacity compared with those in a situation in which the target and the distractor are coded by different names. The results also highlight the role of physical identity of targets: Detection is disproportionately efficient when reproductions of a given signal are presented. Together, the results provide guiding principles for a model of visual detection by a context-sensitive human detector. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual masking during the attentional blink: Tests of the object substitution hypothesis.

When 2 masked targets are presented in a rapid sequence, correct identification of the 1st hinders identification of the 2nd. Visual masking of the 2nd target plays a critical role during this 2nd-target deficit, or "attentional blink" (AB). The object substitution hypothesis (B. Giesbrecht and V. Di Lollo, 1998) predicts that late-stage visual processes involved in object substitution mediate masking of the 2nd target during AB, whereby stronger masking should produce a more severe deficit. Six experiments are presented, together testing this hypothesis. Although masking by object substitution was observed, it did not interact with the AB. An alternative hypothesis is proposed stating that mostly early-stage visual processes mediate the masking effects that are critical to the AB. (PsycINFO Database Record (c) 2010 APA, all rights reserved)