Subliminal Gestalt grouping: Evidence of perceptual grouping by proximity and similarity in absence of conscious perception

Previous studies making use of indirect processing measures have shown that perceptual grouping can occur outside the focus of attention. However, no previous study has examined the possibility of subliminal processing of perceptual grouping. The present work steps forward in the study of perceptual organization, reporting direct evidence of subliminal processing of Gestalt patterns. In two masked priming experiments, Gestalt patterns grouped by proximity or similarity that induced either a horizontal or vertical global orientation of the stimuli were presented as masked primes and followed by visible targets that could be congruent or incongruent with the orientation of the primes. The results showed a reliable priming effect in the complete absence of prime awareness for both proximity and similarity grouping principles. These findings suggest that a phenomenal report of the Gestalt pattern is not mandatory to observe an effect on the response based on the global properties of Gestalt stimuli.     

Gestalt grouping effects in locating past events on timelines

Two experiments required human subjects to date events from the recent or historic past by placing them on timelines. Experiment 1 used parallel sets of timelines containing events similar or related to the test event marked either early or late on the timeline. For three of the seven test events used, subjects located the test event significantly earlier on the ‘early’ than the ‘late’ timeline. In experiment 2, where subjects were required to place a pair of related and a pair of unrelated events on a timeline, related events were significantly more bunched together than unrelated events. The results were interpreted as the consequence of Gestalt principles of perceptual organization.     

Time course of grouping of shape by perceptual closure: effects of spatial proximity and collinearity

We examined time course of grouping of shape by perceptual closure in three experiments using a primed matching task. The gaps between the closure-inducing contours varied in size. In addition, depending on the distribution of the gaps along the closure-inducing contours--occurring at straight contour segments or at the point of change in contour direction--collinearity was either present or absent. In the absence of collinearity, early priming of the shape was observed for spatially close fragments, but not for spatially distant fragments. When collinearity was available, the shape of both spatially close and spatially distant fragments was primed at brief exposures. These results suggest that spatial proximity is critical for the rapid grouping of shape by perceptual closure in the absence of collinearity, but collinearity facilitates the rapid grouping of shape when the closure-inducing fragments are spatially distant. In addition, shape priming persisted over time only when the collinear fragments were spatially close, suggesting that a stable representation of shape depends both on collinearity and spatial proximity between the closure-inducing fragments.     

Memory effects in visual spatial information processing

Eight, ten and twelve year old children were tested on a novel procedure involving the successive presentation of the standard and comparison stimuli. Two hypotheses were evaluated, one dealing with memory effects, and the other with children's pre-testing of choice responses in spatial information processing. It was found, in general, for both spatial perception and coordination of perspectives tasks, that there was no short memory decay for spatial information, but that opportunities to pre-test choice responses improved performance. It was inferred from these data that the performance superiority under simultaneous than successive conditions is attributable to opportunities to pre-test responses and not to memory effects, as opposed to successive conditions is attributable to opportunities to pre-test responses and not to memory effects.     

Developmental trends in utilizing perceptual closure for grouping of shape: effects of spatial proximity and collinearity

In two experiments, visual search was used to study the grouping of shape on the basis of perceptual closure among participants 5-23 years of age. We first showed that young children, like adults, demonstrate an efficient search for a concave target among convex distractors for closed connected stimuli but an inefficient search for open stimuli. Reliable developmental differences, however, were observed in search for fragmented stimuli as a function of spatial proximity and collinearity between the closure-inducing fragments. When only closure was available, search for all the age groups was equally efficient for spatially close fragments and equally inefficient for spatially distant fragments. When closure and collinearity were available, search for spatially close fragments was equally efficient for all the age groups, but search for spatially distant fragments was inefficient for younger children and improved significantly between ages 5 and 10. These findings suggest that young children can utilize closure as efficiently as can adults for the grouping of shape for closed or nearly closed stimuli. When the closure-inducing fragments are spatially distant, only older children and adults, but not 5-year-olds, can utilize collinearity to enhance closure for the perceptual grouping of shape.     

Gestalt and feature-intensive processing: Toward a unified model of human information processing

“Cognitive asynchrony theory,” recently developed in research on aging and memory, implies a functional distinction between the processing of “feature-intensive” items, those with numerous identifiable features, and the processing of images which are relatively sparse in such features and are handled in a more wholistic, “gestalt” manner. The present experiments addressed the question of whether such a distinction exists outside the realms of memory in which it has thus far been addressed. The present work used mental rotation as a model system. Consistent with the predictions of this model, Experiment 1 showed that feature-intensive figures required significantly more time to rotate than did gestalt figures, even though angles of rotation were the same. Experiment 2 demonstrated that feature-intensive processing may involve verbally-accessible semantic systems to a greater degree than is the case with “gestalt” items. Experiment 3 identified significant practice effects of feature-intensive stimuli on the processing of gestalt stimuli, but not the reverse. The results of these experiments indicate that the “gestalt/feature-intensive” processing distinction extends to mental rotation as well as to memory. Implications for the nature of mental representation of verbal and visual materials are discussed.     

Implicit processing of tactile information: evidence from the tactile change detection paradigm

People can maintain accurate representations of visual changes without necessarily being aware of them. Here, we investigate whether a similar phenomenon (implicit change detection) also exists in touch. In Experiments 1 and 2, participants detected the presence of a change between two consecutively-presented tactile displays. Tactile change blindness was observed, with participants failing to report the presence of tactile change. Critically, however, when participants had to make a forced choice response regarding the number of stimuli presented in the two displays, their performance was significantly better than chance (i.e., implicit change detection was observed). Experiment 3 demonstrated that tactile change detection does not necessarily involve a shift of spatial attention toward the location of change, regardless of whether the change is explicitly detected. We conclude that tactile change detection likely results from comparing representations of the two displays, rather than by directing spatial attention to the location of the change.     

Gestalt and feature-intensive processing: Toward a unified model of human information processing

“Cognitive asynchrony theory,” recently developed in research on aging and memory, implies a functional distinction between the processing of “feature-intensive” items, those with numerous identifiable features, and the processing of images which are relatively sparse in such features and are handled in a more wholistic, “gestalt” manner. The present experiments addressed the question of whether such a distinction exists outside the realms of memory in which it has thus far been addressed. The present work used mental rotation as a model system. Consistent with the predictions of this model, Experiment 1 showed that feature-intensive figures required significantly more time to rotate than did gestalt figures, even though angles of rotation were the same. Experiment 2 demonstrated that feature-intensive processing may involve verbally-accessible semantic systems to a greater degree than is the case with “gestalt” items. Experiment 3 identified significant practice effects of feature-intensive stimuli on the processing of gestalt stimuli, but not the reverse. The results of these experiments indicate that the “gestalt/feature-intensive” processing distinction extends to mental rotation as well as to memory. Implications for the nature of mental representation of verbal and visual materials are discussed.     

Task effects on tactile temporal order judgments: when space does and does not matter

The ability to report the temporal order of 2 tactile stimuli (1 applied to each hand) has been shown to decline when the arms are crossed over compared with when they are uncrossed. However, these effects have only been measured when temporal order was reported by stimulus location. It is unknown whether this spatial manipulation of the body affects all tactile temporal order judgments (TOJs) or only those judgments that are spatially defined. The authors examined the effect of crossing the arms on tactile TOJs when stimuli were identified by either spatial (location) or nonspatial (frequency or duration) attributes. Spatial TOJs were significantly impaired when the arms were in crossed compared with uncrossed postures, but there was no effect of posture when order was judged by nonspatial attributes. Task-dependent modulation of the effects of posture was also evident when response complexity was reduced to go/no-go responses. These results suggest that crossing the arms impairs tactile localization and thus spatial TOJs. However, the data also suggest that localization is not a necessary precursor when temporal order can be computed by nonspatial means.     

Throwing spatial light: on topological explanations in Gestalt psychology

Phenomenology and the Cognitive Sciences - It is a well-known fact that mathematics plays a crucial role in physics; in fact, it is virtually impossible to imagine contemporary physics without it....     

Categorization versus distance: Hemispheric differences for processing spatial information

It has been hypothesized that the brain computes two different kinds of spatial-relation representations: one used to assign a spatial relation to a category and the other used to specify metric distance with precision. The present visual half-field experiment offers support for this distinction by showing that the left and right cerebral hemispheres make more effective use of the categorization and metric distance representations, respectively. Furthermore, the inclusion of a bilateral stimulus presentation condition permits the computation of a reversed association that offers additional support for the distinction between two types of spatial-relation representation.     

Sequential effects on speeded information processing: a developmental study

Two experiments were performed to assess age-related changes in sequential effects on choice reaction time (RT). Sequential effects portray the influence of previous trials on the RT to the current stimulus. In Experiment 1, three age groups (7-9, 10-12, and 18-25 years) performed a spatially compatible choice task, with response-to-stimulus intervals (RSIs) of 50 and 500 ms varied between trial blocks. In Experiment 2, three age groups (7-9, 15-16, and 18-25 years) performed the task with spatial stimulus-response (S-R) mappings (compatible versus incompatible) varied between participants. For adults, the experiments yielded a pattern of sequential effects suggestive of "automatic facilitation" (i.e., a first-order repetition effect and a higher order benefit-only pattern for short RSIs) and "subjective expectancy" (i.e., a first-order alternation effect and a higher order cost-benefit pattern for long RSIs). Automatic facilitation was more pronounced for incompatible responses than for compatible responses. Both experiments showed the anticipated decrease in automatic facilitation with advancing age. Finally, the first-order alternation effect showed the predicted age-related increase, but the cost-benefit pattern revealed an opposite trend, suggesting that the first-order and higher order indexes of subjective expectancy may relate to dissociable mechanisms.     

The effect of exogenous spatial attention on auditory information processing

This study investigated the effect of exogenous spatial attention on auditory information processing. In Experiments 1, 2 and 3, temporal order judgment tasks were performed to examine the effect. In Experiment 1 and 2, a cue tone was presented to either the left or right ear, followed by sequential presentation of two target tones. The subjects judged the order of presentation of the target tones. The results showed that subjects heard both tones simultaneously when the target tone, which was presented on the same side as the cue tone, was presented after the target tone on the opposite side. This indicates that spatial exogenous attention was aroused by the cue tone, and facilitated subsequent auditory information processing. Experiment 3 examined whether both cue position and frequency influence the resulting information processing. The same effect of spatial attention was observed, but the effect of attention to a certain frequency was only partially observed. In Experiment 4, a tone fusion judgment task was performed to examine whether the effect of spatial attention occurred in the initial stages of hearing. The result suggests that the effect occurred in the later stages of hearing.     

Cue effects on memory for location when navigating spatial displays

Participants maneuvered a rat image through a circular region on the computer screen to find a hidden target platform, blending aspects of two well-known spatial tasks. Like the Morris water maze task, participants first experienced a series of learning trials before having to navigate to the hidden target platform from different locations and orientations. Like the dot-location task, they determined the location of a position within a two-dimensional circular region. This procedure provided a way to examine how the number of surrounding cues (1, 2, or 3) affects the memory for spatial location in navigation. Memory performance was better when there were more cues and when targets were close to cues, consistent with the idea that cues bolster fine-grain memory, especially in proximal regions. Early and late measures of bias in memory reflected biases in a direction toward the nearest cue, implicating a cue-based category structure of the navigational space. Collectively, results suggest cue-based spatial memory representations that have been inferred from the dot-location task generalize to a navigation task within a simple, computer-based environment, as demonstrated by the good fits of the spatial model developed for the dot-location task ( Fitting, Wedell, & Allen, 2005, 2007 ).     

Prolonged subjective duration near the hands: Effects of hand proximity on temporal reproduction

Psychonomic Bulletin & Review - It has been reported that human visual perception and attention are altered when the hands are nearby. Previous studies indicate that placing hands near stimuli...     

The effects of categorical similarity and feature-space proximity on visual working memory processing

Two patterns of data predict that similarity has a positive effect and a negative effect on visual working memory (VWM) processing. We assume that these two empirical outcomes do not distinguish categorical similarity from feature-space proximity, resulting in this divergence. To investigate how categorical similarity and feature-space proximity modulate VWM, we tested memory for an array of pictures drawn from either mixed categories or a single category in which feature-space proximity varied along a morph continuum in a change-detection task. We found that memory under the mixed-category condition was better than that under the single-category condition, whereas memory under high feature-space proximity was superior to that under low feature-space proximity. These patterns were unaffected by manipulations of stimulus type (faces or scenes), encoding duration (limited or self-paced), and presentation format (simultaneous or sequential). These results are consistent with our hypotheses that categorical similarity inhibits VWM, whereas feature-space proximity facilitates VWM. We also found that memory for items with low feature-space proximity benefited more from mixed-category encoding than that for items with high feature-space proximity. Memory for faces benefited more from mixed-category encoding than scenes, whereas memory for scenes benefited more from feature-space proximity than faces. These results suggest that centre-surround inhibition organization might underlie similarity effects in VWM. Centre-surround inhibition organization for complex real-world objects could have both categorical level and feature-space level. The feature-space level might differ by category.     

Time takes space: selective effects of multitasking on concurrent spatial processing

Many everyday activities require coordination and monitoring of complex relations of future goals and deadlines. Cognitive offloading may provide an efficient strategy for reducing control demands by representing future goals and deadlines as a pattern of spatial relations. We tested the hypothesis that multiple-task monitoring involves time-to-space transformational processes, and that these spatial effects are selective with greater demands on coordinate (metric) than categorical (nonmetric) spatial relation processing. Participants completed a multitasking session in which they monitored four series of deadlines, running on different time scales, while making concurrent coordinate or categorical spatial judgments. We expected and found that multitasking taxes concurrent coordinate, but not categorical, spatial processing. Furthermore, males showed a better multitasking performance than females. These findings provide novel experimental evidence for the hypothesis that efficient multitasking involves metric relational processing.     

The dimensional effects of missing information on choice processing

This paper demonstrates that choice processing may be different in missing information situations than in full information situations depending on whether inferences are used to fill in missing values and the overlap of the missing information itself. It is shown that when individuals do not form inferences to fill in missing values, fewer full attribute-based processes and more processes which accommodate for missing attribute values, alternative-based or given-dimension attribute-based, are used. It is also shown that when a processing shift due to missing information does occur, the overlap of the missing values will affect the type of shift that takes place. If overlap is high, a shift to given-dimension attribute-based processing is more likely, and when overlap is low, a shift to alternative-based processing is more likely. When individuals do form inferences to fill in missing values, processing is more similar to that in full information situations. Finally, it is shown that individuals will often partially fill in missing information, thus moderating the proposed effects.     

The effects of social exclusion on confirmatory information processing

After making a preliminary decision, a balanced search for information that is consistent and inconsistent with one's decision is associated with effective decision making. However, whereas searching for information that is inconsistent with one's preliminary preference arouses the aversive motivational state of cognitive dissonance, evokes negative emotions, and threatens the self, preference‐consistent information reduces dissonance, evokes positive emotions, and has positive implications for the self. Thus, searching for information in a balanced way requires the willingness to face the negative implications of searching for preference‐inconsistent (relative to preference‐consistent) information. Social exclusion has been shown to be associated with impulsive, undercontrolled behavior. Therefore, we expected socially excluded (relative to included or control) participants to be less willing to confront oneself with the unappealing qualities of preference‐inconsistent information and more willing to seek for the appealing qualities of preference‐consistent information. This hypothesis was supported in two studies, with the use of different manipulations of social exclusion. Copyright © 2012 John Wiley & Sons, Ltd.     

The spatial proximity hypothesis of the hand advantage in spatial precuing tasks : A short note concerning discrepant criterion effects

Within the context of the spatial precuing paradigm a consistent finding is that with the hands placed adjacently precuing of two fingers on the same hand results in faster discrete finger responses than precuing of two fingers on different hands. This phenomenon is known as the ‘hand advantage’. Both Miller (1982) and Reeve and Proctor (1984) considered, and rejected, the ‘spatial proximity’ hypothesis as a possible perceptual explanation of the hand advantage. However, data reported by Miller (1982) and Reeve and Proctor (1984) to discount the spatial proximity hypothesis showed a puzzling inconsistency which weakened the strength of the rejection. In this article I address this inconsistency theoretically and experimentally. I conclude that its origin lies in differential operationalizations of the concept ‘preparation effect’. This conclusion justifies rejection of the spatial proximity hypothesis.