Space-time compatibility effects in the auditory modality

Previous research suggests that past and future temporal concepts are spatially represented from left to right along a mental line. And these concepts can both prime motor responses to left or right space and direct visual spatial attention. The present study aimed at investigating the nature of this space-time conceptual metaphor in different auditory tasks. In the first experiment, subjects categorized time-related words (past or future) that were presented binaurally. In the second experiment, subjects detected left-ear or right-ear targets following time-related words. The similar space-time compatibility effects were found in these two experiments. Our results demonstrate that the activation of temporal concepts can both prime motor responses to left or right space and influence the orientation of auditory spatial attention, suggesting that the modality of the stimulus input is unimportant for the left-right mapping of time. These results are explained by the "intermediate coding" account.     

Interference with Rehearsal in Spatial Working Memory in the Absence of Eye Movements

We have previously argued that rehearsal in spatial working memory is interfered with by spatial attention shifts rather than simply by movements to locations in space (Smyth & Scholey, 1994). It is possible, however, that the stimuli intended to induce attention shifts in our experiments also induced eye movements and interfered either with an overt eye movement rehearsal strategy or with a covert one. In the first experiment reported here, subjects fixated while they maintained a sequence of spatial items in memory before recalling them in order. Fixation did not affect recall, but auditory spatial stimuli presented during the interval did decrease performance, and it was further decreased if the stimuli were categorized as coming from the right or the left. A second experiment investigated the effects of auditory spatial stimuli to which no response was ever required and found that these did not interfere with performance, indicating that it is the spatial salience of targets that leads to interference. This interference from spatial input in the absence of any overt movement of the eyes or limbs is interpreted in terms of shifts of spatial attention or spatial monitoring, which Morris (1989) has suggested affects spatial encoding and which our findings suggest also affects reactivation in rehearsal.     

汉语背景下横纵轴上的心理时间线

采用反应区分范式, 以表示过去和未来的时间词为刺激, 对汉语背景下横、纵两轴上的时间表征情况进行了探讨。结果发现, (1)横、纵轴方向上都出现了STEARC效应; (2)右对角线方向上, 出现了服从横轴的减弱的STEARC效应, 且STEARC效应值呈正态分布。以上结果表明, 汉语背景下既存在从左向右的心理时间线, 也存在从上到下的心理时间线, 两种时间表征同时存在, 且横轴表征倾向于占优势。     

Peripheral spatial cues modulate spatial congruency effects: Analysing the “locus” of the cueing modulation

The spatial Stroop effect (slower left/right responses to left/right pointing arrows when they appear at spatially incongruent than at congruent locations) has often been used to examine the processing of irrelevant spatial information. We present data from two experiments in which the magnitude of such location-based interference is drastically reduced when the location of the arrow is precued by a spatial noninformative cue. The main aim of the present study was to clarify whether such modulation takes place at perceptual or at response-related stages of processing. First, we manipulated the spatial compatibility between the direction of the arrow and the location of the response so that each subject would respond with spatially compatible vs. incompatible key presses for each half of the experiment. We found that such manipulation did not have any effect on the standard reduction of the congruency effect by peripheral cues. In a second experiment, subjects made left/right key presses to directional arrows pointing bottom/up, which could appear equally often at left/right/bottom/up locations. In cued trials, we found a reduction of the congruency effect on the vertical axis (stimulus location-direction congruency), whereas congruency was unaffected by cueing in targets presented on the horizontal axis (stimulus-response location congruency). According to these results, we conclude that spatial noninformative cues modulate spatial Stroop interference by reducing the conflict between stimulus dimensions at perceptual- rather than motor-related stages of processing.     

Representing auditory space

Ontario Institute for Studtes tn Education, University of Toronto, Toronto, Canada M5S 1 V6 Auditory space has been characterized as an entity without bound or dimension, as opposed to visual space which is limited in three dimensions. While there is evidence that visual space may be represented mentally in terms of contrastive values on these dimensions, no evidence exists concerning the representation of auditory space. Two experiments used an auditory Stroop-like task to investigate (1) whether the linguistic code for auditory space is comprised of component dimensions as in vision or whether it is unitary, and (2) whether auditory space can also be encoded in a nonlinguistic fashion. Subjects were required to respond to the spatial location of a locative term whose meaning could be congruent, incongruent, or neutral with respect to its location. The findings pointed to the conclusion that when subjects are encouraged to code auditory space linguistically, the code is an undifferentiated symbol or name. Furthermore, some tentative evidence existed that auditory space may also be encoded in a nonlinguistic manner.     

Prismatic Lenses Shift Time Perception

ABSTRACT— Previous studies have demonstrated the involvement of spatial codes in the representation of time and numbers. We took advantage of a well-known spatial modulation (prismatic adaptation) to test the hypothesis that the representation of time is spatially oriented from left to right, with smaller time intervals being represented to the left of larger time intervals. Healthy subjects performed a time-reproduction task and a time-bisection task, before and after leftward and rightward prismatic adaptation. Results showed that prismatic adaptation inducing a rightward orientation of spatial attention produced an overestimation of time intervals, whereas prismatic adaptation inducing a leftward shift of spatial attention produced an underestimation of time intervals. These findings not only confirm that temporal intervals are represented as horizontally arranged in space, but also reveal that spatial modulation of time processing most likely occurs via cuing of spatial attention, and that spatial attention can influence the spatial coding of quantity in different dimensions.     

Spatial metrics of integral and separable dimensions

Two experiments were conducted to investigate the relationship between dimensional integrality and the form of the combination rule or spatial metric used in a similarity judgment task. In Experiment 1, two groups of eight subjects judged the dissimilarity of all pairwise combinations of 12 rectangles differing in height and width (integral dimensions) or 12 circles differing in size and diameter orientation (separable dimensions). The dimensional organization and spatial metric of both sets of dimensions were determined. The results showed that differences in height and width contributed independently to judgments of the overall dissimilarity of rectangles and that these dimensions were combined using a Euclidean metric. In contrast, substantial interactions between circle size and diameter orientation were found. Combinations of these dimensions also appeared to violate the triangle inequality implying that no spatial metric was appropriate. In Experiment 2, parallelogram size and tilt were similarly analyzed. Although some degree of dimensional interaction was observed, it was found that on the average these dimensions were combined using a city-block metric. In a subsequent speeded classification task, orthogonal interference was observed, which suggested that size and tilt are integral dimensions. The implications of both experiments for the supposed association between the Euclidean metric and dimensional integrality are discussed.     

The separability of space and time: Dimensional interaction in the memory trace

The speeded-classification paradigm, adapted from the study of perceptual interactions, was used to examine interactions among features of the short-term memory trace. In each of four experiments, a trial began with the presentation of a pair of stimuli, each member of which occurred either first or second in time and above or below a fixation point. One of the two stimuli was then presented again, and the task was to classify its prior temporal (Experiments 1 and 3) or spatial (Experiments 2 and 4) position. The main question of interest asked whether subjects could selectively attend to one of these occurrence dimensions while ignoring irrelevant variation along the other. The results suggested that whereas subjects can selectively ignore temporal or spatial variation when no recall of the irrelevant dimension’s value is required, they suffer interference when values on both dimensions must be remembered. The obtained patterns of interference are consistent withpostperceptual interactions of the-spatial and temporal components of the memory trace.     

局部注意干扰效应中的眼动特征

采用眼动追踪范式,本研究通过两个实验探讨局部注意干扰效应（LAI）的注意分配特点和机制。实验一采用搜索时间有限的范式,目标呈现70毫秒后消失,在行为和眼动指标上均发现LAI效应：当两个目标距离较近时,反应时增加,正确率降低,总注视时长增长、注视点增加和眼跳速度加快。实验二增加目标呈现时间至1500毫秒以鼓励搜索,产生了比实验一更强烈的LAI效应,且眼跳速度的模式也有不同,说明增加搜索时间并不利于减轻LAI,从而推断LAI的竞争发生在判断阶段,而非搜索和识别目标阶段。     

Structure mapping in spatial reasoning

Four experiments examined whether spatial reasoning about non-spatial concepts is based on mapping concepts to space according to similarities in relational structure. Six- and 7-year-old children without any prior graphing experience were asked to reason with graph-like diagrams. In Experiments 1 and 2, children were taught to map time and quantity to vertical and horizontal lines, and then were asked to judge the relative value of a second-order variable (rate) or a first-order variable (quantity) represented in a function line. Children’s judgments indicated that they mapped concepts to space by aligning similar relational structures: quantity judgments corresponded to line height, and rate judgments corresponded to line slope. These correspondences entail a mapping of first-order concepts to first-order spatial dimensions and second-order concepts to second-order spatial dimensions. Experiments 3 and 4 investigated the role of context in establishing relational structure. Children were taught to map age and rate (Experiment 3) or age and size (Experiment 4) to vertical and horizontal lines, and were then asked to judge the rate or the size represented by a function line. In this context, both rate and size were first-order variables, and children’s judgments corresponded to line height, also a first-order variable. The results indicate that spatial reasoning involves a structure-sensitive mapping between concepts and space.     

Constraints on strategy construction in a speeded discrimination task

In three experiments, subjects reported the identity of a word (above or below) that appeared above or below a fixation point. On some trials, a cue presented 100, 200, 400, 600, 800, or 1,000 msec before the word indicated the relation between position and identity (i.e., whether the dimensions were compatible, e.g., above/above and below/below, or conflicted, e.g., above/below and below/above). On the other trials, the cue was withheld (Experiment 2) or it bore no information about the relation between dimensions (Experiment 1 and 3). In each experiment, the cue reduced reaction time below the level of no-cue or neutral-cue controls, indicating strategic use of the relation between dimensions. Experiments 1 and 2 manipulated the number of potential cues that could occur in a block. A stronger cuing effect was found when one cue could occur (Experiment 2) than when two cues could occur (Experiment 1). Experiment 3 manipulated practice; it revealed that with practice the cuing effect reached asymptote at shorter delays. The asymptote itself did not change. Experiment 4 showed that cue-delay effects were independent of warning interval (warning interval and cue delay confounded in Experiment 1, 2, and 3). The experiments demonstrate construction and utilization of strategies; they show that construction is sensitive to constraints imposed by the subject's goals and abilities and by the structure of the task environment.     

Evidence for two kinds of low-typical instances in a categorization task

Three experiments examined the relationship between instance typicality and reaction time (RT) in a semantic categorization task. In all three experiments, first the instance was presented, and then the category. High-typicality high-imagery instances (e.g., robin) and lowtypicality low-imagery instances (e.g., grackle) were categorized faster than low-typicality highimagery instances (e.g., penguin). Instructing subjects to generate images of the instances had no influence on the pattern of results. The difference in categorization RT for lowimagery low-typicality instances vs. high-imagery high-typicality instances suggests that these instances may be represented differently in memory.     

Endogenous shifts of covert attention operate within multiple coordinate frames: evidence from a feature-priming task

The locations of visual objects and events in the world are represented in a number of different coordinate frameworks. For example, a visual transient is known to attract (exogenous) attention and facilitate performance within an egocentric framework. However, when attention is allocated voluntarily to a particular visual feature (ie endogenous attention), the location of that feature appears to be variously encoded either within an allocentric framework or in a spatially invariant manner. In three experiments we investigated the importance of location for the allocation of endogenous attention and whether egocentric and/or allocentric spatial frameworks are involved. Primes and targets were presented in four conditions designed to vary systematically their spatial relationships in egocentric and allocentric coordinates. A reliable effect of egocentric priming was found in all three experiments, which suggests that endogenous shifts of attention towards targets defined by a particular feature operate in an egocentric representation of visual space. In addition, allocentric priming was also found for targets primed by their colour or shape. This suggests that attending to targets primed by nonspatial attributes results in facilitation that is localised in more than one coordinate frame of spatial reference.     

Visual search for dimensionally redundant pop-out targets: parallel-coactive processing of dimensions is location specific

Three visual search experiments investigated redundancy gains for single and dual odd-one-out feature targets that differed from distractors in orientation, color, or both. In Experiment 1, redundant-target displays contained (a) a single target defined in 2 dimensions, (b) dual targets each defined in a different dimension, or (c) dual targets both defined in the same dimension. The redundancy gains, relative to single nonredundant targets, decreased from the first condition on, with violations of J. Miller's (1982) race model inequality (RMI) manifested only in the first 2 conditions. Experiment 2 systematically varied the spatial separation between dual targets each defined in a different dimension. Violations of the RMI were evident only when the 2 targets occupied nearby locations. Experiment 3 provided evidence of RMI violations by dimensionally redundant targets at both precued (likely) and noncued (unlikely) display locations. Taken together, these results suggest that there is coactivation of a common mechanism by target signals in different dimensions (not by signals in the same dimension), that the coactivation effects are spatially specific, and that the coactivated mechanisms are located at a preattentive, perceptual stage of processing.     

Left–right coding of past and future in language: The mental timeline during sentence processing

The metaphoric mapping theory suggests that abstract concepts, like time, are represented in terms of concrete dimensions such as space. This theory receives support from several lines of research ranging from psychophysics to linguistics and cultural studies; especially strong support comes from recent response time studies. These studies have reported congruency effects between the dimensions of time and space indicating that time evokes spatial representations that may facilitate or impede responses to words with a temporal connotation. The present paper reports the results of three linguistic experiments that examined this congruency effect when participants processed past- and future-related sentences. Response time was shorter when past-related sentences required a left-hand response and future-related sentences a right-hand response than when this mapping of time onto response hand was reversed (Experiment 1). This result suggests that participants can form time–space associations during the processing of sentences and thus this result is consistent with the view that time is mentally represented from left to right. The activation of these time–space associations, however, appears to be non-automatic as shown by the results of Experiments 2 and 3 when participants were asked to perform a non-temporal meaning discrimination task.     

Is it for real? Evaluating authenticity of musical pitch-space synesthesia

In spatial-sequence synesthesia, ordinal sequences are visualized in explicit spatial locations. We examined a recently documented subtype in which musical notes are represented in spatial configurations, to verify consistency and automaticity of musical pitch-space (M-S) synesthesia. An M-S synesthete performed a mapping pre-task (Exp. 1) used to indicate the locations of 7 auditory or visually presented notes, in 2 sessions a month apart. Results revealed strong correlations between sessions, suggesting the synesthete's musical forms were consistent over time. Experiment 2 assessed automaticity of M-S synesthesia. The same synesthete and matched controls preformed a spatial Stroop-like task. Participants were presented with an auditory or visual musical note and then had to reach for an asterisk (target) with a mouse cursor. The target appeared in a compatible or incompatible location (according to the synesthete's spatial representation). A compatibility effect was found for the synesthete but not for controls. The synesthete was significantly faster when the target appeared in compatible locations than in incompatible ones. Our findings show that for synesthetes, auditory and visually presented notes automatically trigger attention to specific spatial locations according to their specific M-S associations.     

Movement and working memory: Patterns and positions in space

Five experiments are reported in which subjects were asked to remember short, visually presented sequences of whole body movement patterns, words, and spatial positions. The items were recalled in order in a memory span paradigm. During presentation of the items to be remembered subjects simply watched, or they carried out a concurrent activity involving articulatory suppression, movement to external spatial targets, or body-related movement. When the movement patterns to be remembered were familiar to subjects, movement span was not disrupted by articulatory suppression or movement to spatial targets but was disrupted by body-related movement. This movement suppression task, however, did not interfere with performance on a spatial span task or on verbal span. It is concluded that the memory for patterns of limb movement differs from memory for movement to spatial targets and that accounts of visuo-spatial processes in working memory involve the latter type of movement.     

The role of goal representations in moving to temporal and spatial targets

Traditionally, movement kinematics are thought to reflect physical properties (e.g., position and time) of movement targets. However, targets may also evoke intentional goals like “to be in a certain position at a given time”. Therefore, kinematics may be viewed not as a reaction to stimuli, but rather as the means to attain intended goals. In the present study participants performed continuous reversal movements. It was first shown that kinematics towards temporal and spatial targets differ from kinematics away from those targets. Further, kinematics are different for movements to temporal (relatively short movement times, high and late peak velocity) and spatial (relatively long movement times, early peak velocity) targets (Experiments 1 and 2). In order to obtain evidence for the influence of goal representations on kinematics, combinations of temporal and spatial targets were investigated in Experiments 3 and 4. Specifically, the conditions were: spatial targets always present with varying temporal targets, temporal targets always present with varying spatial targets, and combined and separate spatial and temporal targets. Not only the physical features, but also how the targets were represented as movement goals, were important. Thus, movement kinematics do not simply reflect stimulus properties, but rather the representation of the intended goal.     

Knowing where is different from knowing what: Distinct response time profiles and accuracy effects for target location,orientation, and color probability

When a location is cued, targets appearing at that location are detected more quickly. When a target feature is cued, targets bearing that feature are detected more quickly. These attentional cueing effects are only superficially similar. More detailed analyses find distinct temporal and accuracy profiles for the two different types of cues. This pattern parallels work with probability manipulations, where both feature and spatial probability are known to affect detection accuracy and reaction times. However, little has been done by way of comparing these effects. Are probability manipulations on space and features distinct? In a series of five experiments, we systematically varied spatial probability and feature probability along two dimensions (orientation or color). In addition, we decomposed response times into initiation and movement components. Targets appearing at the probable location were reported more quickly and more accurately regardless of whether the report was based on orientation or color. On the other hand, when either color probability or orientation probability was manipulated, response time and accuracy improvements were specific for that probable feature dimension. Decomposition of the response time benefits demonstrated that spatial probability only affected initiation times, whereas manipulations of feature probability affected both initiation and movement times. As detection was made more difficult, the two effects further diverged, with spatial probability disproportionally affecting initiation times and feature probability disproportionately affecting accuracy. In conclusion, all manipulations of probability, whether spatial or featural, affect detection. However, only feature probability affects perceptual precision, and precision effects are specific to the probable attribute.     

A comparison of methods for estimating directions in egocentric space

A central issue for researchers of human spatial knowledge, whether focused on perceptually guided action or cognitive-map acquisition, is knowledge of egocentric directions, directions from the body to objects and places. Several methods exist for measuring this knowledge. We compared two particularly important methods, manual pointing with a dial and whole-body rotation (body heading), under various conditions of sensory or memory access to targets. In two experiments, blindfolded body rotation resulted in the greatest variability of performance (variable error), while the manual dial resulted in greater consistent bias (constant error). The variability of performance with body rotation was no greater than that of the dial when subjects' memory loads for directions to targets was reduced by allowing them to peek at targets in between trials, point to concurrent auditory targets, or point with their eyes open. In both experiments, errors with the manual dial were greater for directions to targets that were further from the closest orthogonal axis (ahead, behind, right, left), while errors with body rotation with restricted perceptual access were greater for directions to targets that were further from an axis straight ahead of subjects. This suggests that the two methods will produce evidence of different organizational frameworks for egocentric spatial knowledge. Implications for the structures and processes that underlie egocentric spatial knowledge, and are involved in estimating directions, are discussed, as is the value of decomposing absolute errors into variable and constant errors.