Haptic experiences influence visually acquired memories: Reference frames during multimodal spatial learning

In two experiments, we investigated whether reference frames acquired through touch could influence memories for locations learned through vision. Participants learned two objects through touch, and haptic egocentric (Experiment 1) and environmental (Experiment 2) cues encouraged selection of a specific reference frame. Participants later learned eight new objects through vision. Haptic cues were manipulated, whereas visual learning was held constant in order to observe any potential influence of the haptically experienced reference frame on memories for visually learned locations. When the haptically experienced reference frame was defined primarily by egocentric cues, cue manipulation had no effect on memories for objects learned through vision. Instead, visually learned locations were remembered using a reference frame selected from the visual study perspective. When the haptically experienced reference frame was defined by both egocentric and environmental cues, visually learned objects were remembered in the context of the haptically experienced reference frame. These findings support the common reference frame hypothesis, which proposes that locations learned through different sensory modalities are represented within a common reference frame.     

Orientation dependence of spatial memory acquired from auditory experience

The present study investigated whether memory for a room-sized spatial layout learned through auditory localization of sounds exhibits orientation dependence similar to that observed for spatial memory acquired from stationary viewing of the environment. Participants learned spatial layouts by viewing objects or localizing sounds and then performed judgments of relative direction among remembered locations. The results showed that direction judgments following auditory learning were performed most accurately at a particular orientation in the same way as were those following visual learning, indicating that auditorily encoded spatial memory is orientation dependent. In combination with previous findings that spatial memories derived from haptic and proprioceptive experiences are also orientation dependent, the present finding suggests that orientation dependence is a general functional property of human spatial memory independent of learning modality.     

The role of body-based sensory information in the acquisition of enduring spatial representations

Although many previous studies have shown that body-based sensory modalities such as vestibular, kinesthetic, and efferent information are useful for acquiring spatial information about one's immediate environment, relatively little work has examined how these modalities affect the acquisition of long-term spatial memory. Three groups of participants learned locations along a 146 m indoor route, and subsequently pointed to these locations, estimated distances between them, and constructed maps of the environment. One group had access to visual, proprioceptive, and inertial information, another had access to matched visual and matched inertial information, and another had access only to matched visual information. In contrast to previous findings examining transient, online spatial representations, our results showed very few differences among groups in the accuracy of the spatial memories acquired. The only difference was the improved pointing accuracy of participants who had access to proprioceptive information relative to that of participants in the other conditions. Results are discussed in terms of differential sensory contributions to transient and enduring spatial representations.     

Erratum to: The organization of room geometry and object layout geometry in human memory

Research with humans and with nonhuman species has suggested a special role of room geometry in spatial memory functioning. In two experiments, participants learned the configuration of a room with four corners, along with the configuration of four objects within the room, while standing in a fixed position at the room’s periphery. The configurations were either rectangular (Experiment 1) or irregular (Experiment 2). Room geometry was not recalled better than object layout geometry, and memories for both configurations were orientation dependent. These results suggest that room geometry and object layout geometry are represented similarly in human memory, at least in situations that promote long-term learning of object locations. There were also some differences between corners and objects in orientation dependence, suggesting that the two sources of information are represented in similar but separate spatial reference systems.     

The organization of room geometry and object layout geometry in human memory

Research with humans and with nonhuman species has suggested a special role of room geometry in spatial memory functioning. In two experiments, participants learned the configuration of a room with four corners, along with the configuration of four objects within the room, while standing in a fixed position at the room's periphery. The configurations were either rectangular (Experiment 1) or irregular (Experiment 2). Room geometry was not recalled better than object layout geometry, and memories for both configurations were orientation dependent. These results suggest that room geometry and object layout geometry are represented similarly in human memory, at least in situations that promote long-term learning of object locations. There were also some differences between corners and objects in orientation dependence, suggesting that the two sources of information are represented in similar but separate spatial reference systems. [corrected]     

Learning directions of objects specified by vision,spatial audition,or auditory spatial language

The modality by which object azimuths (directions) are presented affects learning of multiple locations. In Experiment 1, participants learned sets of three and five object azimuths specified by a visual virtual environment, spatial audition (3D sound), or auditory spatial language. Five azimuths were learned faster when specified by spatial modalities (vision, audition) than by language. Experiment 2 equated the modalities for proprioceptive cues and eliminated spatial cues unique to vision (optic flow) and audition (differential binaural signals). There remained a learning disadvantage for spatial language. We attribute this result to the cost of indirect processing from words to spatial representations.     

Intrinsic frames of reference in haptic spatial learning

It has been proposed that spatial reference frames with which object locations are specified in memory are intrinsic to a to-be-remembered spatial layout (intrinsic reference theory). Although this theory has been supported by accumulating evidence, it has only been collected from paradigms in which the entire spatial layout was simultaneously visible to observers. The present study was designed to examine the generality of the theory by investigating whether the geometric structure of a spatial layout (bilateral symmetry) influences selection of spatial reference frames when object locations are sequentially learned through haptic exploration. In two experiments, participants learned the spatial layout solely by touch and performed judgments of relative direction among objects using their spatial memories. Results indicated that the geometric structure can provide a spatial cue for establishing reference frames as long as it is accentuated by explicit instructions (Experiment 1) or alignment with an egocentric orientation (Experiment 2). These results are entirely consistent with those from previous studies in which spatial information was encoded through simultaneous viewing of all object locations, suggesting that the intrinsic reference theory is not specific to a type of spatial memory acquired by the particular learning method but instead generalizes to spatial memories learned through a variety of encoding conditions. In particular, the present findings suggest that spatial memories that follow the intrinsic reference theory function equivalently regardless of the modality in which spatial information is encoded.     

Path information effects in visual and proprioceptive spatial learning

Objects in an environment are often encountered sequentially during spatial learning, forming a path along which object locations are experienced. The present study investigated the effect of spatial information conveyed through the path in visual and proprioceptive learning of a room-sized spatial layout, exploring whether different modalities differentially depend on the integrity of the path. Learning object locations along a coherent path was compared with learning them in a spatially random manner. Path integrity had little effect on visual learning, whereas learning with the coherent path produced better memory performance than random order learning for proprioceptive learning. These results suggest that path information has differential effects in visual and proprioceptive spatial learning, perhaps due to a difference in the way one establishes a reference frame for representing relative locations of objects.     

Cross-sensory reference frame transfer in spatial memory: the case of proprioceptive learning

In three experiments, we investigated whether the information available to visual perception prior to encoding the locations of objects in a path through proprioception would influence the reference direction from which the spatial memory was formed. Participants walked a path whose orientation was misaligned to the walls of the enclosing room and to the square sheet that covered the path prior to learning (Exp. 1) and, in addition, to the intrinsic structure of a layout studied visually prior to walking the path and to the orientation of stripes drawn on the floor (Exps. 2 and 3). Despite the availability of prior visual information, participants constructed spatial memories that were aligned with the canonical axes of the path, as opposed to the reference directions primed by visual experience. The results are discussed in the context of previous studies documenting transfer of reference frames within and across perceptual modalities.     

Locomotion,incidental learning,and the selection

In three experiments, we examined the effects of locomotion and incidental learning on the formation of spatial memories. Participants learned the locations of objects in a room and then made judgments of relative direction, using their memories (e.g., "Imagine you are standing at the clock, facing the jar. Point to the book"). The experiments manipulated the number of headings experienced, the amount of interaction with the objects, and whether the participants were informed that their memories of the layout would be tested. When participants were required to maintain a constant body orientation during learning (Experiment 1), they represented the layout in terms of a single reference direction parallel to that orientation. When they were allowed to move freely in the room (Experiment 2), they seemed to use two orthogonal reference axes aligned with the walls of the enclosing room. Extensive movement under incidental learning conditions (Experiment 3) yielded a mixture of these two encoding strategies across participants. There was no evidence that locomotion, interaction with objects, or incidental learning led to the formation of spatial memories that differed from those formed from static viewing.     

Orientation-specificity in kinesthetic spatial learning: The role of multiple orientations

In the current study we tested whether multiple orientations in kinesthetic learning affected how flexibly spatial information is stored and later used in making location judgments. Three groups learned simple routes by walking them while blindfolded, with (1) multiple orientations achieved through normal walking, (2) multiple orientations achieved through backward walking, or (3) a single orientation achieved through walking without turning (which required forward, backward, and sideways walking). When subjects had experienced multiple orientations while learning the routes, later directional judgments were equally accurate (and equally rapid) regardless of whether the judgments were aligned or were contra-aligned with the orientation of the routes as originally learned. In contrast, when routes were learned in a single orientation (without turning), subsequent judgments on contra-aligned trials were both less accurate and slower than judgments on aligned trials. Thus, multiple orientations are important to establish orientation-free, flexible use of spatial information in a kinesthetic learning environment. This contrasts with the pattern of results typically found in visual spatial learning and suggests that the factors that affect orientation specificity of spatial use may differ across spatial modality.     

序列本体感觉学习获得稳定的自我中心空间表征*

通过同步视觉或者序列本体感觉,被试学习不规则场景。学习完毕之后,在面对学习方向、自主旋转240°、和持续旋转直至迷向3种运动条件下,被试随机指出各个物体的位置。迷向导致同步视觉学习组指向的内部一致性显著变差,而序列本体感觉学习组不受迷向影响。离线的相对位置判断任务表明两组被试的环境中心空间表征没有差异。这证明通过序列本体感觉学习被试也可以形成稳定的自我中心空间表征,支持了空间快照理论的扩展和空间认知的功能等价假说。     

Spatial memories of virtual environments: How egocentric experience, intrinsic structure, and extrinsic structure interact

Previous research has uncovered three primary cues that influence spatial memory organization:egocentric experience, intrinsic structure (object defined), and extrinsic structure (environment defined). In the present experiments, we assessed the relative importance of these cues when all three were available during learning. Participants learned layouts from two perspectives in immersive virtual reality. In Experiment 1, axes defined by intrinsic and extrinsic structures were in conflict, and learning occurred from two perspectives, each aligned with either the intrinsic or the extrinsic structure. Spatial memories were organized around a reference direction selected from the first perspective, regardless of its alignment with intrinsic or extrinsic structures. In Experiment 2, axes defined by intrinsic and extrinsic structures were congruent, and spatial memories were organized around reference axes defined by those congruent structures, rather than by the initially experienced view. The findings are discussed in the context of spatial memory theory as it relates to real and virtual environments.     

Object-centered reference systems and human spatial memory

The present study investigated the role of object-centered reference systems in memories of objects' locations. Participants committed to memory the locations and orientations of either 11 human avatars (Experiment 1) or 11 animal models (Experiment 2) displayed in a desktop virtual environment and then completed judgments of relative directions, in which they pointed to objects from imagined vantage points corresponding to the locations of the objects. Results showed that, with avatars, performance was better when the imagined heading was congruent with the facing direction of the avatar located at the imagined vantage point. With animal models, no such facilitation was found. For both types of stimuli, performance was better for the learning view than for the novel 135° view. Results demonstrate that memories of the locations of objects are affected by object-centered reference systems and are consistent with conjectures that spatial memories are hierarchies of spatial reference systems, with higher levels corresponding to larger scales of space.     

Perceptual orientational asymmetries: A comparison of visual and haptic space

Stimulus orientation discrimination was investigated in visual and haptic modalities under conditions of simultaneous matching and memory. Discrimination of vertical and horizontal was significantly more accurate than discrimination of oblique stimulus orientations (45°, 135°, 225°, and 315°) for both modalities; haptic errors, however, were significantly greater at each orientation. While subjects were reliably more accurate in visually matching oblique stimulus orientations to a standard than producing them from memory, for the haptic modality, differences between memory and matching conditions were less consistent across the orientations sampled.     

Stepping Into a Map: Initial Heading Direction Influences Spatial Memory Flexibility

Learning a novel environment involves integrating first‐person perceptual and motoric experiences with developing knowledge about the overall structure of the surroundings. The present experiments provide insights into the parallel development of these egocentric and allocentric memories by intentionally conflicting body‐ and world‐centered frames of reference during learning, and measuring outcomes via online and offline measures. Results of two experiments demonstrate faster learning and increased memory flexibility following route perspective reading (Experiment 1) and virtual navigation (Experiment 2) when participants begin exploring the environment on a northward (vs. any other direction) allocentric heading. We suggest that learning advantages due to aligning body‐centered (left/right/forward/back) with world‐centered (NSEW) reference frames are indicative of three features of spatial memory development and representation. First, memories for egocentric and allocentric information develop in parallel during novel environment learning. Second, cognitive maps have a preferred orientation relative to world‐centered coordinates. Finally, this preferred orientation corresponds to traditional orientation of physical maps (i.e., north is upward), suggesting strong associations between daily perceptual and motor experiences and the manner in which we preferentially represent spatial knowledge.     

Functional equivalence of spatial images from touch and vision: evidence from spatial updating in blind and sighted individuals

This research examined whether visual and haptic map learning yield functionally equivalent spatial images in working memory, as evidenced by similar encoding bias and updating performance. In 3 experiments, participants learned 4-point routes either by seeing or feeling the maps. At test, blindfolded participants made spatial judgments about the maps from imagined perspectives that were either aligned or misaligned with the maps as represented in working memory. Results from Experiments 1 and 2 revealed a highly similar pattern of latencies and errors between visual and haptic conditions. These findings extend the well-known alignment biases for visual map learning to haptic map learning, provide further evidence of haptic updating, and most important, show that learning from the 2 modalities yields very similar performance across all conditions. Experiment 3 found the same encoding biases and updating performance with blind individuals, demonstrating that functional equivalence cannot be due to visual recoding and is consistent with an amodal hypothesis of spatial images.     

Two varieties of perceived length

The perception of length depends on the mode of stimulation. When Ss were asked to judge the apparent lengths of blocks presented either visually or proprioceptively (between thumb and finger of one hand), visual length was proportional to block length, whereas proprioceptive length was an accelerating function of block length. When both visual and proprioceptive stimulation occurred simultaneously (S both saw and felt a block), the visual input was preemptive.     

The Effect of Imageability and Predicability of Cues in Autobiographical Memory

Four experiments investigated the role of imagery in the recollection of autobiographical memories. The first two experiments examined the effects of word imageability and word frequency on the retrieval of personal memories in a cued autobiographical memory task. They showed that the imageability of cues (but not frequency) mediates specificity in the recall of personal memories. Experiment 2 explored how different imagery modalities (visual, olfactory, tactile, auditory, and motor) influence autobiographical retrieval. Consistent with research on imagery modalities in verbal learning paradigms, visual imageability emerged as the most significant predictor of specificity. Experiments 3 and 4 examined how far a knowledge-based account of imagery effects might account for these effects, using predicability as a measure of semantic richness of a cue. Results found that visual imageability of cues accounted for more variance in specificity of recall than did predicability. The results are explained in terms of the way images represent the most efficient form of summarizing the information that can be used at each stage of the recollection process: setting the retrieval plan, strategic search, and evaluation of candidate episodes.     

Geometric cues,reference frames,and the equivalence of experienced-aligned and novel-aligned views in human spatial memory

Spatial memories are often organized around reference frames, and environmental shape provides a salient cue to reference frame selection. To date, however, the environmental cues responsible for influencing reference frame selection remain relatively unknown. To connect research on reference frame selection with that on orientation via environmental shape, we explored the extent to which geometric cues were incidentally encoded and represented in memory by evaluating their influence on reference frame selection. Using a virtual environment equipped with a head-mounted-display, we presented participants with to-be-remembered object arrays. We manipulated whether the experienced viewpoint was aligned or misaligned with global (i.e., the principal axis of space) or local (i.e., wall orientations) geometric cues. During subsequent judgments of relative direction (i.e., participants imagined standing at one object, facing a second object, and pointed toward a third object), we show that performance was best when imagining perspectives aligned with these geometric cues; moreover, global geometric cues were sufficient for reference frame selection, global and local geometric cues were capable of exerting differential influence on reference frame selection, and performance from experienced-imagined perspectives was equivalent to novel-imagined perspectives aligned with geometric cues. These results explicitly connect theory regarding spatial reference frame selection and spatial orientation via environmental shape and indicate that spatial memories are organized around fundamental geometric properties of space.