Spatial disinhibition of orientation analyzers

Following the successive presentation of two masking gratings (M1 and M2), subjects were required to detect the presence or absence of a single vertical line (TS). When the orientations of the two masks were optimal, M1 was able to reduce the masking effect of M2 on the TS. For a vertical TS, disinhibition was maximal when the orientations of M1 and M2 were similar and was minimal when the orientational difference was greater than 15 deg. It is suggested that the spatial selectivity of the disinhibition function reflects the activity of neurons tuned to orientation, and that the disinhibition masking paradigm may be a useful psychophysical technique to measure tuning functions of other feature detectors.     

Spatial orientation in weightless environments.

Illusions of body inversion and of vehicle inversion can be evoked by exposure to weightlessness in the microgravity conditions of orbital and parabolic flight. Such illusions can involve all possible combinations of self-inversion and vehicle inversion. In the absence of any patterns of external stimulation, individuals may lose all sense of body orientation to their surroundings while retaining a sense of their overall body configuration and cognitive awareness of their actual position. Touch and pressure cues provide a perceptual 'down' in the absence of visual input. When vision is allowed, apparent orientation is influenced by a variety of factors including the direction of gaze, the architectural layout of the vehicle, and sight of the body. The relative importance of the various factors affecting orientation changes with repeated exposure. The virtual absence of sensations of falling during exposure to free-fall emphasizes the role of cognitive factors in experienced orientation.     

Gaze orientation interferes with mental numerical representation

Number comparison tasks are characterized by distance and size effects. The distance effect reveals that the higher the distance is between two numbers, the easier their magnitude comparison is. Accordingly, people are thought to represent numbers on a spatial dimension, the mental number line, on which any given number corresponds to a location on the line. The size effect, instead, states that at any given distance, comparing two small numbers is easier than comparing two large numbers, thus suggesting that larger numbers are more vaguely represented than smaller ones. In the present work we first tested whether the participants were adopting a spatial strategy to solve a very simple numbers comparison task, by assessing the presence of the distance and the magnitude effect. Secondarily, we focused on the influence of gaze position on their performance. The present results provide evidence that gaze direction interferes with number comparisons, worsening the vague representation of larger numbers and further supporting the hypothesis of the overlapping between physical and mental spaces.     

A high density ERP comparison of mental rotation and mental size transformation

To compare mental rotation and mental size transformation, 128-channel EEG was recorded while subjects performed both tasks using random two-dimensional shapes as stimuli. Behavioural results showed significant linear effects of both size transformation and mental rotation on reaction times. Rotation ERPs showed experimental effects at two latencies: a bilateral component distributed over posterior parietal electrodes at a latency of approximately 232-300ms and a second component at approximately 424-492ms distributed over right anterior parietal electrodes. The latency and spatial distribution of this second effect is consistent with previous research indicating a functional connection between this component and mental rotation. ERPs for the size-transformation task showed an effect at 180-228ms distributed bilaterally over occipital-temporal electrodes. These results are consistent with previous hemodynamic imaging studies that show involvement of parietal cortex in mental rotation and also the involvement of BA 19 in size-transformation tasks. However, the superior temporal resolution of the present data indicates that BA 19 activation may occur at a latency that is more likely related to apparent motion than to the size-transformation operation per se.     

Spatial and orientation specific integration in the tilt illusion

Lateral inhibition across a population of cells in visual cortex which are tuned to local orientation has been proposed and widely accepted as a basic process in the analysis of contour in the visual field. The tilt illusion is usually explained in terms of this inhibition. Experiments are reported which cast new light on the analysis of visual orientation. It is shown that tilt illusions may be obtained with very thin inducing annuli which are spatially remote from the test figure. In experiments in which remote crossed-grating plaids were used, an illusion which was pattern (global) rather than component (local) selective was seen. It is difficult to account for these observations in terms of local inhibitory mechanisms. Rather, the results support the existence of a secondary mechanism which is involved in basic orientation analytic processes. The relevance of these observations to models of visual contour analysis is discussed.     

Spatial orientation of a limb using egocentric reference points

Testing the hypothesis that spatial localization can be based on an abstracted spatial location code, rather than on stored proprioceptive information, orientation of an unseen limb was contrasted under intra- and interlimb-movement conditions. In Experiment 1, movements were executed in the midline either vertically upward or horizontally forward in the sagittal plane. These results revealed that intralimb errors were smaller than interlimb errors only at the most distant criterion spatial targets, and it was hypothesized that positioning of a limb could be mediated by a spatial location code if spatial targets were coded in association with body reference points. Experiment 2 tested the egocentric referent hypothesis further by manipulating the availability of body-based spatial reference points under intra- and interlimb conditions. At spatial targets that could be coded in conjunction with body reference points, no difference was found between intra- and interlimb accuracy. In contrast, at spatial targets where body reference points were absent, or at least made difficult to rely on, accuracy was greater in the intralimb condition. It was concluded that spatial reference points, in this instance body-based, are necessary if the spatial positioning of a limb is to be based on the spatial location code. The data were also discussed within a more comprehensive framework of spatial frames of reference.     

Spatial representations elicit dual-coding effects in mental imagery

Spatial aspects of words are associated with their canonical locations in the real world. Yet little research has tested whether spatial associations denoted in language comprehension generalize to their corresponding images. We directly tested the spatial aspects of mental imagery in picture and word processing (Experiment 1). We also tested whether spatial representations of motion words produce similar perceptual-interference effects as demonstrated by object words (Experiment 2). Findings revealed that words denoting an upward spatial location produced slower responses to targets appearing at the top of the display, whereas words denoting a downward spatial location produced slower responses to targets appearing at the bottom of the display. Perceptual-interference effects did not obtain for pictures or for words lacking a spatial relation. These findings provide greater empirical support for the perceptual-symbols system theory ( Barsalou, 1999, 2008 ).     

Spatial distance and mental construal of social events

Construal-level theory proposes that increasing the reported spatial distance of events leads individuals to represent the events by their central, abstract, global features (high-level construal) rather than by their peripheral, concrete, local features (low-level construal). Results of two experiments indicated that participants preferred to identify actions as ends rather than as means to a greater extent when these actions occurred at a spatially distant, as opposed to near, location (Study 1), and that they used more abstract language to recall spatially distant events, compared with near events (Study 2). These findings suggest that spatially distant events are associated with high-level construals, and that spatial distance can be conceptualized as a dimension of psychological distance.     

Spatial orientation from optic flow in the central visual field

Previous research has shown that stimulation of the central visual field with radial flow patterns (produced by forward motion) can induce perceived self-motion, but has failed to demonstrate effects on postural stability of either radial flow patterns or lamellar flow patterns (produced by horizontal translation) in the central visual field. The present study examined the effects of lamellar and radial flow on postural stability when stimulation was restricted to the central visual field. Displays simulating observer motion through a volume of randomly positioned points were observed binocularly through a window that limited the field of view to 15 degrees. The velocity of each display varied according to the sum of four sine functions of prime frequencies. Changes in posture were used to measure changes in perceived spatial orientation. A frequency analysis of postural sway indicated that increased sway occurred at the frequencies of motion simulated in the display for both lamellar and radial flow. These results suggest that both radial and lamellar optic flow are effective for determining spatial orientation when stimulation is limited to the central visual field.     

The relationship between Quest religious orientation,forgiveness, and mental health

Little is known about how religious orientation, specifically Quest, relates to forgiveness. In addition, research on the relationship between Quest and psychological distress has yielded conflicting findings, possibly because previous studies have conceptualised Quest as a unidimensional construct. This study investigated how Quest and its recently recognised dimensions related to forgiveness and psychological distress. Participants (N?=?242) were undergraduates from a Midwestern Catholic university. They completed measures of Quest, forgiveness, and psychological distress. Results suggested that certain dimensions of Quest were better predictors of forgiveness (e.g., Tentativeness, Exploration, and Moralistic Interpretation) and distress (e.g., Change, Religious Angst, and Existential Motives). Importantly, results revealed that the same dimensions that were positively related to distress were negatively related to forgiveness. Further, the relationship between Quest and forgiveness was moderated by the perceived tolerance/open-mindedness level of the offender; it seems that individuals with a questing nature are less forgiving when the offender is perceived as less tolerant.     

Religious orientation and mental health: a study with Turkish university students

The present study examined the relationship between religious orientation and mental health symptoms among Turkish students. A total of 341 undergraduate students between the ages of 18 and 26 completed the Brief Symptom Inventory and Age Universal Intrinsic-Extrinsic Scale. Extrinsic orientation was found to be correlated positively with symptoms of anxiety and depression. There were also significant correlations between hostility scores and both intrinsic and extrinsic religious orientations. Patterns were similar to those reported previously, but correlations were mostly in the .10-.14 range. In multiple-regression models, extrinsic orientation emerged as the only significant predictor for hostility, anxiety, and depression; however, only 2% of the variance was explained.     

Spatial imagery of novel places based on visual scene transformation

The hippocampus is known to maintain memories of object-place associations that can produce a scene expectation at a novel viewpoint. To implement such capabilities, the memorized distances and directions of an object from the viewer at a fixed location should be integrated with the imaginary displacement to the new viewpoint. However, neural dynamics of such scene expectation at the novel viewpoint have not been discussed. In this study, we propose a method of coding novel places based on visual scene transformation as a component of the object-place memory in the hippocampus. In this coding, a novel place is represented by a transformed version of a viewer’s scene with imaginary displacement. When the places of individual objects are stored with the coding in the hippocampus, the object’s displacement at the imaginary viewpoint can be evaluated through the comparison of a transformed viewer’s scene with the stored scene. Results of computer experiments demonstrated that the coding successfully produced scene expectation of a three object arrangement at a novel viewpoint. Such the scene expectation was retained even without similarities between the imaginary scene and the real scene at the location, where the imaginary scenes only functioned as indices to denote the topographical relationship between object locations. The results suggest that the hippocampus uses the place coding based on scene transformation and implements the spatial imagery of object-place associations from the novel viewpoint.     

Doing gesture promotes learning a mental transformation task better than seeing gesture

Performing action has been found to have a greater impact on learning than observing action. Here we ask whether a particular type of action – the gestures that accompany talk – affect learning in a comparable way. We gave 158 6‐year‐old children instruction in a mental transformation task. Half the children were asked to produce a Move gesture relevant to the task; half were asked to produce a Point gesture. The children also observed the experimenter producing either a Move or Point gesture. Children who produced a Move gesture improved more than children who observed the Move gesture. Neither producing nor observing the Point gesture facilitated learning. Doing gesture promotes learning better than seeing gesture, as long as the gesture conveys information that could help solve the task.