Object-specific function,geometry, and the comprehension of in and on

Three experiments are reported which examined the relative effects of geometry and object-specific function on the comprehension of the spatial prepositions in and on. The first experiment manipulated the height of a located object on top of a pile of other objects in containers which were primarily containers of solids (e.g., a suitcase) or liquids (e.g., an aquarium). The association between located object and reference object was also varied (by using different types of objects as located objects). In was found to be more appropriate to describe the same object in containers of solids compared to containers of liquids, although no effects of located object association were found. Experiments 2 and 3 manipulated similar variables with supporting surfaces rather than containers, and examined the effects of functional control on the comprehension of on. The studies provide evidence for the importance of functional relations on the comprehension of on. In addition effects of located object association were found, but only when there was no clear evidence for the absence or presence of functional control. The results are discussed in relation to the differential effects of object knowledge on the comprehension of spatial prepositions.     

The influence of environmental context in interpersonal observation–execution

Cyclical upper-limb movements involuntarily deviate from a primary movement direction when the actor concurrently observes incongruent biological motion. We examined whether environmental context influences such motor interference during interpersonal observation–execution. Participants executed continuous horizontal arm movements while observing congruent horizontal or incongruent curvilinear biological movements with or without the presence of an object positioned as an obstacle or distractor. When participants were observing a curvilinear movement, an object located within the movement space became an obstacle, and, thus, the curvilinear trajectory was essential to reach into horizontal space. When acting as a distractor, or with no object, the curvilinear trajectory was no longer essential. For observing horizontal movements, objects were located at the same relative locations as in the curvilinear movement condition. We found greater involuntary movement deviation when observing curvilinear than horizontal movements. Also, there was an influence of context only when observing horizontal movements, with greater deviation exhibited in the presence of a large obstacle. These findings suggest that the influence of environmental context is underpinned by the (mis-)matching of observed and executed actions as incongruent biological motion is primarily coded via bottom-up sensorimotor processes, whilst the congruent condition incorporates surrounding environmental features to modulate the bottom-up sensorimotor processes.     

Spatial term apprehension with a reference object’s rotation in three-dimensional space

It has been reported that the overall shapes of spatial categorical patterns of projective spatial terms such as above and below are not influenced by the rotation of a reference object on a two-dimensional (2D) upright plane. However, is this also true in three-dimensional (3D) space? This study shows the dynamic aspects of the apprehension of projective spatial terms in 3D space by detailing how the rotation of a reference object with an inherent front influences the apprehension of projective spatial terms on a level plane by mapping their spatial categorical patterns. The experiment was designed to examine how spatial categorical patterns on a level plane changed with the rotation of a reference object with an inherent front in 3D computer graphics space. We manipulated the rotation of a reference object with an inherent front at three levels (0°, 90°, and 180° rotations) and examined how such manipulation changed the overall spatial categorical patterns of four basic Japanese projective spatial terms: mae, ushiro, hidari, and migi (similar to in front of, behind, to the left of, and to the right of in English, respectively). The results show that spatial term apprehension was affected by the rotation of the reference object in 3D space. In particular, rotation influenced the mae–ushiro and hidari–migi systems differently. The results also imply that our understanding of projective spatial terms on a level plane in 3D space is affected dynamically by visual information from 3D cues.     

Abrupt onsets capture attention independent of top-down control settings

Previous research using a spatial cuing paradigm in which a distractor cue preceded the target has shown that new objects presented with abrupt onsets only capture attention when observers are set to look for them (e.g., Folk, Remington, & Johnston, 1992). In the present study, we used the same spatial cuing paradigm as Folk et al. (1992) to demonstrate that even when observers have an attentional set for a color singleton or a specific color feature, an irrelevant new object presented with an abrupt onset interfered with search. We also show that the identity of the abrupt-onset distractor affects responses to the target, indicating that at some point spatial attention was allocated to the abrupt onset. We conclude that abrupt onsets ornew objects override a top-down set for color. Abrupt onsets or new objects appear to capture attention independently of top-down control settings.     

Hierarchical attention in discriminating objects at different levels of specificity

An implicit assumption of studies in the attentional literature has been that global and local levels of attention are involved in object recognition. To investigate this assumption, a divided attention task was used in which hierarchical figures were presented to prime the subsequent discrimination of target objects at different levels of category identity (basic and subordinate). Target objects were identified among distractor objects that varied in their degree of visual similarity to the targets. Hierarchical figures were also presented at different sizes and as individual global and local elements in order to investigate whether attention-priming effects on object discrimination were due to grouping/parsing operations or spatial extent. The results showed that local processing primed subordinate object discriminations when the objects were visually similar. Global processing primed basic object discriminations, regardless of the similarity of the distractors, and subordinate object discriminations when the objects were visually dissimilar. It was proposed that global and local processing aids the selection of perceptual attributes of objects that are diagnostic for recognition and that selection is based on two mechanisms: spatial extent and grouping/parsing operations.     

Semantic interference from visual object recognition on visual imagery

A new technique for examining the interaction between visual object recognition and visual imagery is reported. The "image-picture interference" paradigm requires participants to generate and make a response to a mental image of a previously memorized object, while ignoring a simultaneously presented picture distractor. Responses in 2 imagery tasks (making left-right higher spatial judgments and making taller-wider judgments) were longer when the simultaneous picture distractor was categorically related to the target distractor relative to unrelated and neutral target-distractor combinations. In contrast, performance was not influenced in this way when the distractor was a related word, when a semantic categorization decision was made to the target, or when distractor and target were visually but not categorically related to one another. The authors discuss these findings in terms of the semantic representations shared by visual object recognition and visual imagery that mediate performance.     

Effects of verbal and nonverbal interference on spatial and object visual working memory

We tested the hypothesis that a verbal coding mechanism is necessarily engaged by object, but not spatial, visual working memory tasks. We employed a dual-task procedure that paired n-back working memory tasks with domain-specific distractor trials inserted into each interstimulus interval of the n-back tasks. In two experiments, object n-back performance demonstrated greater sensitivity to verbal distraction, whereas spatial n-back performance demonstrated greater sensitivity to motion distraction. Visual object and spatial working memory may differ fundamentally in that the mnemonic representation of featural characteristics of objects incorporates a verbal (perhaps semantic) code, whereas the mnemonic representation of the location of objects does not. Thus, the processes supporting working memory for these two types of information may differ in more ways than those dictated by the "what/where" organization of the visual system, a fact more easily reconciled with a component process than a memory systems account of working memory function.     

Frames of reference in spatial memories acquired from language

Four experiments examined reference systems in spatial memories acquired from language. Participants read narratives that located 4 objects in canonical (front, back, left, right) or noncanonical (left front, right front, left back, right back) positions around them. Participants' focus of attention was first set on each of the 4 objects, and then they were asked to report the name of the object at the location indicated by a direction word or an iconic arrow. The results indicated that spatial memories were represented in terms of intrinsic (object-to-object) reference systems, which were selected using egocentric cues (e.g., alignment with body axes). Results also indicated that linguistic direction cues were comprehended in terms of egocentric reference systems, whereas iconic arrows were not.     

Launching at a distance: The effect of spatial markers

It has been widely reported that spatial contiguity is important to judgements of causality involving one object launching another [Michotte's “launching effect” (1963, 1991)]. The present study examined the impact of different types of spatial markers on causal judgements of a distal launch (one object approaching other, stopping short of it, and the second object subsequently moving along the same trajectory). The spatial markers were objects that either partially or completely bridged the spatial gap between two objects (Experiment 1), or they were dashed lines that marked the stopping location of the first object or the starting location of the second object (Experiment 2). The presence of either objects or dashed lines could produce higher causal ratings, but the location of the marker mattered. The results suggest that altering a cause's ability to predict when the effect would occur (via a spatial marker) and the presence of a conduit for energy transmission have independent effects on causal judgements of object interaction.     

Neural correlates of spatial term use

The current research used event-related brain potentials (ERPs) to assess the processes underlying online apprehension of the spatial term above. Constituent steps defined within G. D. Logan and D. D. Sadler's (1996) computational theory of apprehension were associated with distinct modulations of ERPs. Specifically, finding the relevant objects was associated with an amplitude modulation of P3; competition in assigning directions to space was associated with modulation of a frontal slow wave; and computing and comparing the spatial relation was associated with modulation of a parietal slow wave. These modulations were differentially influenced by the type of reference frame used to define the spatial term and by the participant's response. The current study supports this decompositional approach to apprehension and provides a means of assessing each step independently.     

Not all visual memories are created equal

Two experiments examined how well the long-term visual memories of objects that are encountered multiple times during visual search are updated. Participants searched for a target two or four times (e.g., white cat) among distractors that shared the target's colour, category, or were unrelated while their eye movements were recorded. Following the search, a surprise visual memory test was given. With additional object presentations, only target memory reliably improved; distractor memory was unaffected by the number of object presentations. Regression analyses using the eye movement variables as predictors indicated that number of object presentations predicted target memory with no additional impact of other viewing measures. In contrast, distractor memory was best predicted by the viewing pattern on the distractor objects. Finally, Experiment 2 showed that target memory was influenced by number of target object presentations, not number of searches for the target. Each of these experiments demonstrates visual memory differences between target and distractor objects and may provide insight into representational differences in visual memory.     

Effects of a moving distractor object on time-to-contact judgments

The effects of moving task-irrelevant objects on time-to-contact (TTC) judgments were examined in 5 experiments. Observers viewed a directly approaching target in the presence of a distractor object moving in parallel with the target. In Experiments 1 to 4, observers decided whether the target would have collided with them earlier or later than a standard (absolute identification task). A contrast effect was observed: If the distractor arrived later than the target, it caused a bias toward early responses, relative to the condition without a distractor. The early-arriving distractor had no significant effect. The pattern of results was unaltered when potentially confounding information from individual visual cues was removed. The availability of stereoscopic information reduced the effect. The contrast effect was also observed if target and distractor were abstract geometric objects rather than simulations of real-world vehicles, rendering less likely a simple safety strategy activated by a potentially threatening distractor. Experiment 5 showed that the effect of the late-arriving distractor generalized to a prediction-motion task. The results indicate that task-irrelevant information in the background has to be considered in revision of time-to-contact theory.     

Functional influences on orienting a reference frame

Spatial relational terms like above are defined with respect to a reference frame. Reference frames are imposed on reference objects and define the space in which to search for a located object. Reference frames have a number of parameters that must be set during spatial term assignment, including origin, scale, and orientation. Previous research has shown that a functional relationship between objects in the scene influences the selection of a reference frame (Carlson-Radvansky & Radvansky, 1996). However, because this work operated at the level of the reference frame, generalizing across various spatial terms, it is unclear how function had its influence. One possibility is that function influences how the parameters of a reference frame are set. Consistent with this idea, Carlson-Radvansky, Covey, and Lattanzi (1999) showed an influence of function on where the origin of a reference frame was imposed. The present paper demonstrates that function also influences how the orientation of the axes of a reference frame is set. The implications for setting multiple parameters of a reference frame are discussed.     

Ignoring famous faces: category-specific dilution of distractor interference

The extent to which famous distractor faces can be ignored was assessed in six experiments. Subjects categorized famous printed target names as those of pop stars or politicians, while attempting to ignore a flanking famous face distractor that could be congruent (e.g, a politician's name and face) or incongruent (e.g., a politician's name with a pop stars face). Congruency effects on reaction times indicated distractor intrusion. An additional, response-neutral flanker (neither pop star nor politician) could also be present. Congruency effects from the critical distractor face were reduced (diluted) by the presence of an intact anonymous face, but not by phase-shifted versions, inverted faces, or meaningful nonface objects. By contrast, congruency effects from other types of distracting objects (musical instruments, fruits), when printed names for these classes were categorized, were diluted equivalently by intact faces, phase-shifted faces, or meaningful nonface objects. Our results suggest that distractor faces act differently from other types of distractors, suffering from only face-specific capacity limits.     

Selecting a reference object

One way to describe the location of an object is to relate it to another object. Often there are many nearby objects, each of which could serve as a candidate to be the reference object. A common theoretical assumption is that features that make a given object salient relative to the candidate set are instrumental in determining which is selected. The current research tests this assumption, assessing the relative importance of spatial, perceptual, and functional-interactive features. Three experiments demonstrated that spatial features have the strongest influence on reference object selection, with the perceptual feature of color playing no significant role. Functional-interactive features were shown to be spatially dependent, having an influence only when the spatial configuration enabled an interaction between the located object and the reference object. These findings challenge the common perspective that salience in and of itself dictates reference object selection and argue for a reliance on spatial features.     

Semantic interference in language production is due to graded similarity,not response relevance

There is an ongoing debate on the question whether semantic interference effects in language production reflect competitive processes at the level of lexical selection or whether they reflect a post-lexical bottleneck, occupied in particular by response-relevant distractor words. To disentangle item-inherent categorical relatedness and task-related response relevance effects, we combined the picture–word interference task with the conditional naming paradigm in an orthogonal design, varying categorical relatedness and task-related response relevance independent of each other. Participants were instructed to name only objects that are typically seen in or on the water (e.g. canoe) and refrain from naming objects that are typically located outside the water (e.g. bike), and vice versa. Semantic relatedness and the response relevance of superimposed distractor words were manipulated orthogonally. The pattern of results revealed no evidence for response relevance as a major source of semantic interference effects in the PWI paradigm. In contrast, our data demonstrate that semantic similarity beyond categorical relations is critical for interference effects to be observed. Together, these findings provide support for the assumption that lexical selection is competitive and that semantic interference effects in the PWI paradigm reflect this competition.