Processing of tactile spatial information with crossed fingers

The erroneous perception of two objects when one object is touched with crossed fingers has been explained as an inability of the brain to correctly perceive the crossed fingers' positions. This account is examined in Experiment 1, in which the perceived position of stimuli touching the crossed fingers is mapped. Crossing the third finger over the fourth displaced the perceived stimulus position counter-clockwise; crossing the third under the fourth displaced perceptions clockwise. In Experiment 2, perceived positions were found to fit a model of tactile saturation past the point of the functional range of action of the fingers. Two major conclusions are drawn: (a) Tactile stimuli are always perceived as if fingers were uncrossed, and (b) spatial mapping is present only within the functional range of finger excursion.     

An isolation effect in serial memory for spatial information

This paper reports the first demonstration of an isolation effect or von Restorff effect (von Restorff, 1933) in the context of a spatial-memory task: Short-term serial recall was enhanced for both the location and the serial position of one red dot presented amongst a sequence of otherwise black dots. When the serial position of the isolate was fixed, the spatial isolation effect only emerged when participants received a control block of trials before the block of isolation trials (Experiment 1). However, when the serial position of the isolate was varied across isolation trials, an isolation effect was still produced regardless of condition order (Experiment 2). It is suggested that both temporal grouping strategies and greater item-specific processing may have contributed to the enhanced retention of the isolate.     

An isolation effect in serial memory for spatial information

This paper reports the first demonstration of an isolation effect or von Restorff effect (von Restorff, 1933 von Restorff, H. 1933. Uber die Wirkung von Bereichsbildungen im Spurenfeld [On the effect of spheres formations in the trace field]. Psychologische Forschung, 18: 299–342. [Crossref] , [Google Scholar]) in the context of a spatial-memory task: Short-term serial recall was enhanced for both the location and the serial position of one red dot presented amongst a sequence of otherwise black dots. When the serial position of the isolate was fixed, the spatial isolation effect only emerged when participants received a control block of trials before the block of isolation trials (Experiment 1). However, when the serial position of the isolate was varied across isolation trials, an isolation effect was still produced regardless of condition order (Experiment 2). It is suggested that both temporal grouping strategies and greater item-specific processing may have contributed to the enhanced retention of the isolate.     

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.     

The effect of spatial frequency information and visual similarity in threat detection

In the current research, we sought to examine the role of spatial frequency on the detection of threat using a speeded visual search paradigm. Participants searched for threat-relevant (snakes or spiders) or non-threat-relevant (frogs or cockroaches) targets in an array of neutral (flowers or mushrooms) distracters, and we measured search performance with images filtered to contain different levels (high and low) of spatial frequency information. The results replicate previous work demonstrating more rapid detection of threatening versus non-threatening stimuli [e.g. LoBue, V. & DeLoache, J. S. (2008). Detecting the snake in the grass: Attention to fear-relevant stimuli by adults and young children. Psychological Science, 19, 284–289. doi:10.1111/j.1467-9280.2008.02081.x]. Most importantly, the results suggest that low spatial frequency or relatively coarse levels of visual information is sufficient for the rapid and accurate detection of threatening stimuli. Furthermore, the results also suggest that visual similarity between the stimuli used in the search tasks plays a significant role in speeded detection. The results are discussed in terms of the theoretical implications for the rapid detection of threat and methodological implications for properly accounting for similarity between the stimuli in visual search studies.     

The effect of spatial and nonspatial contextual information on visual object memory

Recent research has found visual object memory can be stored as part of a larger scene representation rather than independently of scene context. The present study examined how spatial and nonspatial contextual information modulate visual object memory. Two experiments tested participants’ visual memory by using a change detection task in which a target object's orientation was either the same as it appeared during initial viewing or changed. In addition, we examined the effect of spatial and nonspatial contextual manipulations on change detection performance. The results revealed that visual object representations can be maintained reliably after viewing arrays of objects. Moreover, change detection performance was significantly higher when either spatial or nonspatial contextual information remained the same in the test image. We concluded that while processing complex visual stimuli such as object arrays, visual object memory can be stored as part of a comprehensive scene representation, and both spatial and nonspatial contextual changes modulate visual memory retrieval and comparison.     

Automatic response activation of implicit spatial information: Evidence from the SNARC effect

In the present paper, we focus on how irrelevant implicit spatial information is processed. By irrelevant we mean information that is not required to fulfill the task and by implicit we mean information that is not directly available in the external stimulus. A good example of a task in which such information exists is the SNARC task [Dehaene, S., Bossini, S., & Giraux, P. (1993). The mental representation of parity and number magnitude. Journal of Experimental Psychology: General, 122, 371-396]. The SNARC effect shows that the magnitude of a number, although irrelevant to the task, activates spatial codes that may interfere with the task-related response. These spatial associations exist both for the horizontal and the vertical direction. In Experiment 1, response keys were discriminating in the vertical or the horizontal direction. It is shown that the impact of the numerical spatial codes on overt behavior, although automatic, depends on the response discrimination of the horizontal or the vertical dimension. In Experiment 2, response keys were assigned such that both the horizontal and the vertical direction of the response were discriminating. In this case, the horizontal and the vertical dimension of the irrelevant numerical spatial codes were shown to interact. In general, the results are in line with the response-discrimination account [Ansorge, U., & Wühr, P. (2004). A response-discrimination account of the Simon effect. Journal of Experimental Psychology: Human Perception and Performance, 30, 365-377].     

The effect of path length and display size on memory for spatial information

In serial memory for spatial information, some studies showed that recall performance suffers when the distance between successive locations increases relatively to the size of the display in which they are presented (the path length effect; e.g., Parmentier et al., 2005) but not when distance is increased by enlarging the size of the display (e.g., Smyth & Scholey, 1994). In the present study, we examined the effect of varying the absolute and relative distance between to-be-remembered items on memory for spatial information. We manipulated path length using small (15″) and large (64″) screens within the same design. In two experiments, we showed that distance was disruptive mainly when it is varied relatively to a fixed reference frame, though increasing the size of the display also had a small deleterious effect on recall. The insertion of a retention interval did not influence these effects, suggesting that rehearsal plays a minor role in mediating the effects of distance on serial spatial memory. We discuss the potential role of perceptual organization in light of the pattern of results.     

On the coding of spatial information

Two experiments studied recall of objects and their locations in an intentional-incidental learning paradigm. When studying spatial information, the usual incidental condition is not truly incidental, because subjects often deliberately use locations to help organize objects for recall. Therefore, a true incidental task was devised in which neither objects nor locations were expected to be recalled and for which explicit encoding of locations was irrelevant. There was only a small loss in recall of objects or their locations in a true incidental condition. It was concluded that a great deal of location information is automatically coded into long-term memory storage in the sense that active processing is not required. The data were contrasted with incidental processing of other attributes, such as color. Although adults performed better than children, there were no age-related interactions, indicating similarity of functioning at all ages studied.     

Processing locational and orientational information

In choice reaction time (RT) tasks, college students verified the truth of displays expressing spatial relations between two objects. The relations werelocational (A is left of B) ororientational (A and B are horizontal). The objects were names of states in the United States, symbols, or letter arrays. The objects were memorized prior to the display (states and letters) or were presented as part of the display (symbols and letters). In the location tasks with both states and symbols, locatives were spatial (right, left, above, below) or compass (north, south, east, west). Distance between states was also varied. When location was judged, horizontally aligned stimuli resulted in slower responses than vertically aligned stimuli, independently of materials and locative set. Reaction time was inversely related to distance. When orientation was judged, responses to horizontal pairs of states were slower than responses to vertical pairs of states, responses to horizontal pairs of letters were faster than responses to vertical pairs, and RT did not depend upon the orientation of symbols. This pattern of results suggests that orientational judgments are influenced by type of materials and the entext to which the material has been encoded (i.e., memorized). Locational judgments reflect a potent source of difficulty not present in orientation tasks, namely, telling left from right. Alternative explanations of the right-left effect are discussed.     

Bayesian integration of spatial information

Spatial judgments and actions are often based on multiple cues. The authors review a multitude of phenomena on the integration of spatial cues in diverse species to consider how nearly optimally animals combine the cues. Under the banner of Bayesian perception, cues are sometimes combined and weighted in a near optimal fashion. In other instances when cues are combined, how optimal the integration is might be unclear. Only 1 cue may be relied on, or cues may seem to compete with one another. The authors attempt to bring some order to the diversity by taking into account the subjective discrepancy in the dictates of multiple cues. When cues are too discrepant, it may be best to rely on 1 cue source. When cues are not too discrepant, it may be advantageous to combine cues. Such a dual principle provides an extended Bayesian framework for understanding the functional reasons for the integration of spatial cues.     

Algorithms for processing spatial information

Pairs of stimuli taken from a psychometric measure of spatial aptitude were shown to 9-year-olds, 13-year-olds, and adults. The stimuli in pairs were (a) either identical or mirror images, and (b) presented in orientations that differed by 0-150 degrees. Individuals judged, as rapidly as possible, if the stimuli in a pair would be identical or mirror images if presented at the same orientation. In Experiment 1, in which the stimuli were letter-like characters, at all ages most persons solved the problems using an algorithm in which an individual encodes the stimuli in working memory, mentally rotates one stimulus to the orientation of the other, compares them to determine if they are identical, and responds. In Experiment 2, the stimuli were multielement flags; here, the modal algorithm for both 9- and 13-year-olds differed from the previously described algorithm in that if the comparison process revealed that the stimuli were dissimilar, individuals did not respond immediately, but continued processing until a self-imposed deadline was reached. Among adults, the modal algorithm was the same one used in Experiment 1. Results are discussed in terms of the roles of encoding in contributing to the use of a particular algorithm.     

Flexible use of source information: Processing components of the inconsistency effect in person memory

The impact of social expectancies on person memory is investigated in two experiments using a source-recognition paradigm. Multinomial model analyses disentangled effects on item-memory, source-memory, and heuristic reconstructive guessing processes. Cognitive load and retention interval were manipulated. In two pilot studies and Experiment 1, participants were presented equal numbers of consistent and inconsistent statements about two stereotyped targets. Source-memory showed an inconsistency effect that is restricted to conditions with load at encoding and longer retention interval. Consistency biases in reconstructive guessing of statement-person associations emerged under load. Item-memory exhibited only a small inconsistency effect in conditions without load and short retention interval. Experiment 2 yielded similar results, although expectancies were induced on-line via the distribution of positive and negative behaviors across non-stereotyped targets. Findings support a model of flexible use of source information, demonstrate the importance of source memory, and of assessing it separately from item recognition and reconstructive guessing.     

Integrating spatial information across experiences

The current study examined the potential influence of existing spatial knowledge on the coding of new spatial information. In the Main experiment, participants learned the locations of five objects before completing a perspective-taking task. Subsequently, they studied the same five objects and five additional objects from a new location before completing a second perspective-taking task. Task performance following the first learning phase was best from perspectives aligned with the learning view. However, following the second learning phase, performance was best from the perspective aligned with the second view. A supplementary manipulation increased the salience of the initial view through environmental structure as well as the number of objects present. Results indicated that the initial learning view was preferred throughout the experiment. The role of assimilation and accommodation mechanisms in spatial memory, and the conditions under which they occur, are discussed.     

The effect of flumazenil on acquisition, retention, and retrieval of spatial information.

The effect of flumazenil, a benzodiazepine-receptor antagonist, was evaluated in a spatial-reference memory procedure in a water maze. Flumazenil (1.0, 3.0, and 10.0 mg/kg, ip) did not modify acquisition of spatial information. Retention was similar between control and experimental rats 24 h after the training phase, as all groups showed bias to the target quadrant in a free swim trial. However, 10 days later, only flumazenil-injected rats (3.0 mg/kg) showed bias to the target quadrant. Flumazenil did not affect retrieval of spatial information in a group of well-trained rats. These results suggest that a benzodiazepine-receptor mediated endogenous mechanism is activated during learning of spatial tasks and that its blockade facilitates retention of spatial information.     

Simultaneous processing of verbal and spatial information

Two experiments investigated the generality of the selective interference phenomenon by studying several different concurrent tasks, each involving either verbal or spatial information, and a range of retention intervals from 10 to 30 sec. The results supported the selective interference predictions, since the interference in performance was greater when the two simultaneous tasks both involved either verbal information or spatial information than when one of the tasks involved verbal and the other spatial information. It was concluded that not only was the selective interference phenomenon a rather general effect but that, since it was unaffected by changes in the nature of the component tasks, it was also probably caused by central processing capacity limitations rather than by competition for a specific structural mechanism.     

The coding and transformation of spatial information

The present paper examines the mental processes involved in inferring perspective changes that result either from the rotation of a spatial array or from the rotation of the viewer of that array. Piaget has shown that viewer-rotation problems are difficult when children must choose among pictures or models of an array from differing perspectives. We showed earlier that, with parallel tasks, array-rotation problems are much easier than viewer-rotation problems. We proposed that in solving these problems, subjects interpret the instructions literally, recoding the position of the viewer vis-à-vis the array for viewer-rotation problems and recoding the array with respect to its spatial framework for arrayrotation problems. At that time, we proposed a second principle to explain why Piagetian perspective problems are so difficult; namely, that children have special difficulty in recoding viewer position (egocentrism). The present experiments show that, when subjects are asked a different sort of question on such tasks, viewer-rotation problems become easy and array-rotation problems become difficult. The results show that the difficulty of the Piagetian perspective task is not due to egocentrism; i.e., to difficulty recoding viewer position. The results of all these rotational-transformation tasks can be explained if we add a different second principle to the principle of literalness of problem interpretation. This new second principle posits that the array is fixed vis-à-vis the spatial context rather than that the viewer is fixed vis-à-vis the array.     

Configural face encoding and spatial frequency information

Configural relations and a critical band of spatial frequencies (SFs) in the middle range are particularly important for face recognition. We report the results of four experiments in which the relationship between these two types of information was examined. In Experiments 1, 2A, and 2B, the face inversion effect (FIE) was used to probe configural face encoding. Recognition of upright and inverted faces and nonface objects was measured in four conditions: a no-filter condition and three SF conditions (low, medium, and high frequency). We found significant FIEs of comparable magnitudes for all frequency conditions. In Experiment 3, discrimination of faces on the basis of either configural or featural modifications was measured under the same four conditions. Although the ability to discriminate configural modifications was superior in the medium-frequency condition, so was the ability to discriminate featural modifications. We conclude that the band of SF that is critical for face recognition does not contribute preferentially to configural encoding.