Mental rotation of static and dynamic figures

Previous studies comparing performance on standard (i.e., static) and dynamic spatial test items have concluded that the two item types measure different abilities. Such conclusions about the uniqueness of static and dynamic spatial abilities seem premature, however, since only a limited number of dynamic spatial tasks have been utilized in research and these have differed markedly from their static counterparts. In the present studies, tasks were designed to require a common mental operation (mental rotation) under static and dynamic conditions. Correlations between static and dynamic performance ranged from .80 to .90. This appears to suggest that the emergence of a unique dynamic ability factor depends on the utilization of certain specialized tasks (e.g., arrival time tasks) with mental operations much different than those required by conventional spatial tests. In other words, it is apparently the requirement for different cognitive processes and not the processing of stimulus motion per se that distinguishes performance onsome dynamic tasks from performance on some standard static tasks.     

Inhibition of return in static and dynamic displays

Inhibition of return (IOR) causes people to be slower to return their attention to a recently attended object (object-based IOR) or location (location-based IOR). In attempts to separately measure the two components, moving stimuli have been used that permit the dissociation of the attended object from its location when it was attended. The implicit assumption has been that both object- and locationbased components of IOR will operate whenever the cued object and cued location are identical. We show here that although this assumption may be true in a static display, it appears to be unwarranted when moving stimuli are involved: Very little IOR is observed when a cued object moves away from, and then subsequently returns to, its initial location. Thus, the processes that underlie IOR operate very differently in static versus dynamic scenes.     

Repetition priming and recognition of dynamic and static chimeras

Chimeric faces, produced by combining the top half of a familiar face with the bottom half of a different familiar face, are difficult to recognise explicitly. However, given that they contain potentially useful configurational and featural information for face recognition, they might nevertheless produce some activation of representations of their constituent faces. Repetition priming with dynamic and static facial chimeras was used to test this possibility. Whereas half-faces produced significant repetition priming of their familiar counterparts, both types of chimera did not. When analyses were restricted to faces that were recognised during the prime phase, repetition priming was both significant, and equivalent, for chimeras and half-faces. The results suggest that the constituents of a facial chimera must be parsed, and recognised, in order for them to cause repetition priming for their familiar counterparts. Facial motion does not help with the parsing of a facial chimera.     

Perception of dynamic information in static handwritten forms

Handwriting recognition presents a problem for most theories of letter perception. How do people accurately discriminate letters given the variability in handwritten forms? We propose that perceivers detect and capitalize on information relating to production inherent in the static trace of the handwritten letter. In an "implicit detection" task, subjects' ability to detect stroke direction in a series of handwritten characters was found to be influenced by the particular drawing method used to generate the stimuli. Similar results were obtained in an "explicit detection" task in which the subjects were asked to speculate on the drawing method used to generate the samples. Our findings suggest that perceivers are able to extract information relating to production from the static trace. We propose that they can then use this information in conjunction with their knowledge of a common production process, shared by both producers and perceivers, to aid character recognition.     

Visual representations of dynamic actions from static pictures

We investigated how subjects used their knowledge of biomechanical constraints when judging whether different items were in balance or in the process of falling, as a function of their angle of slant. In the first experiment, the stimuli were pictures of postures of a human body, of a wooden mannequin, and of a skeleton. The results show that for these 3 items, fall responses appeared for a smaller slant angle for a backward slant than for a forward one. This difference may reflect the influence of biomechanical constraints. To verify whether the asymmetry of the responses to the mannequin and the skeleton was genuine or due to some semantic context effect, a second experiment was run with only pictures of a wooden mannequin. The same asymmetry was observed. In a third experiment, falling judgments were obtained for pictures of a human body and of a structurally comparable artifactual object. The asymmetry of the fall responses appeared only for the human body.     

Facilitation by exogenous attention for static and dynamic gestalt groups

Attentional mechanisms allow the brain to selectively allocate its resources to stimuli of interest within the huge amount of information reaching its sensory systems. The voluntary component of attention, endogenous attention, can be allocated in a flexible manner depending on the goals and strategies of the observer. On the other hand, the reflexive component, exogenous attention, is driven by the stimulus. Here, we investigated how exogenous attention is deployed to moving stimuli that form distinct perceptual groups. We showed that exogenous attention is deployed according to a reference frame that moves along with the stimulus. Moreover, in addition to the cued stimulus, exogenous attention is deployed to all elements forming a perceptual group. These properties provide a basis for the efficient deployment of exogenous attention under ecological viewing conditions.     

Similar mechanisms underlie curvature comparison by static and dynamic touch

In four experiments, we tested whether haptic comparison of curvature ranging from ?41m to +41m is qualitatively the same for static and for dynamic touch. In Experiments 1 and 3, we tested whether static and dynamic curvature discrimination are based on height differences, attitude (slope) differences, curvature differences, or a combination of these geometrical variables. It was found that both static and dynamic haptic curvature discrimination are based on attitude differences. In Experiments 2 and 4, we tested whether this mechanism leads to errors in the comparison of stimuli with different lengths for static and dynamic touch, respectively. If the judgments are based on attitude differences, subjects will make systematic errors in these comparisons. In both experiments, we found that subjects compared the curvatures of strips of the same length veridically, whereas they made systematic errors if they were required to compare the curvatures of strips of different lengths. Longer stimuli were judged to be more curved than shorter stimuli with the same curvature. We conclude that similar mechanisms underlie static and dynamic haptic curvature comparison. Moreover, additional data comparison showed that static and dynamic curvature comparison is not only qualitatively, but also quantitatively similar.     

Perceptual-motor contributions to static and dynamic balance control in children

The authors addressed balance control in children from the perspective of skill development and examined the relationship between specific perceptual and motor skills and static and dynamic balance performance. Fifty 11- to 13-year-old children performed a series of 1-legged balance tasks while standing on a force platform. Postural control was reflected in the maximum displacement of the center of mass in anterior-posterior and mediolateral directions. Simple visual, discrimination, and choice reaction times; sustained attention; visuomotor coordination; kinesthesis; and depth perception were also assessed in a series of perceptual and motor tests. The correlation analysis revealed that balancing under static conditions was strongly associated with the ability to perceive and process visual information, which is important for feedback-based control of balance. On the other hand, when greater task demands were imposed on the system under dynamic balancing conditions, the ability to respond to the destabilizing hip abductions-adductions in order to maintain equilibrium was associated with motor response speed, suggesting the use of a descending, feedforward control strategy. Therefore, like adults, 11- to 13-year-old children have the ability to select varying balance strategies (feedback, feedforward, or both), depending on the constraints of a particular task.     

Muscle coordination and force variability during static and dynamic tracking tasks

This study examined muscular activity patterns of extensor and flexor muscles and variability of forces during static and dynamic tracking tasks using compensatory and pursuit display. Fourteen volunteers performed isometric actions in two conditions: (i) a static tracking task consisting of flexion/pronation, ulnar deviation, extension/supination and radial deviation of the wrist at 20% maximum voluntary contraction (MVC), and (ii) a dynamic tracking task aiming at following a moving target at 20% MVC in the four directions of contraction. Surface electromyography (SEMG) from extensor carpi ulnaris, extensor carpi radialis, flexor carpi ulnaris and flexor digitorum superficialis muscles and exerted forces in the transverse and sagittal plane were recorded. Normalized root mean square and mutual information (index of functional connectivity within muscles) of SEMGs and the standard deviation and sample entropy of force signals were extracted. Larger SEMG amplitudes were found for the dynamic task (p < .05), while normalized mutual information between muscle pairs was larger for the static task (p < .05). Larger size of variability (standard deviation of force) concomitant with smaller sample entropy was observed for the dynamic task compared with the static task (p < .01 for both). These findings underline a rescaling of the muscles’ respective contribution influencing force variability relying on feedback and feed-forward control strategies in relation to display modes during static and dynamic tracking tasks.     

Temperature perception on the hand during static versus dynamic contact with a surface

Innocuous cooling or heating of the forearm can evoke nociceptive sensations, such as burning, stinging, and pricking (low-threshold thermal nociception, LTN), that are inhibited by dynamic contact. In the present study, I investigated whether LTN can also be perceived on the hand, and if so, whether it is normally suppressed by active touching. Innocuous cold (28°, 25°, and 18°C) and warm (38°, 40°, and 43°C) temperatures were delivered to the distal metacarpal pads and intermediate and distal phalanges of the fingers via a handgrip thermode that subjects either statically held or actively grasped. The same temperatures were delivered to the forearm via another thermode that either rested on the arm or was touched to the arm. Subjects rated the intensity of thermal (warmth, cold) and nociceptive (e.g., burning) sensations and indicated the qualities of sensation experienced. The results showed that LTN can be perceived on the hand, although less frequently and less intensely than on the forearm. Dynamic contact inhibited nociceptive and thermal sensations on the hand, although less strongly than on the forearm. These findings indicate that temperature perception on the hand is attenuated and its quality is changed when thermal stimulation is accompanied by dynamic tactile stimulation, as it is during haptic exploration.     

Emotion recognition of static and dynamic faces in autism spectrum disorder

There is substantial evidence for facial emotion recognition (FER) deficits in autism spectrum disorder (ASD). The extent of this impairment, however, remains unclear, and there is some suggestion that clinical groups might benefit from the use of dynamic rather than static images. High-functioning individuals with ASD (n = 36) and typically developing controls (n = 36) completed a computerised FER task involving static and dynamic expressions of the six basic emotions. The ASD group showed poorer overall performance in identifying anger and disgust and were disadvantaged by dynamic (relative to static) stimuli when presented with sad expressions. Among both groups, however, dynamic stimuli appeared to improve recognition of anger. This research provides further evidence of specific impairment in the recognition of negative emotions in ASD, but argues against any broad advantages associated with the use of dynamic displays.     

False recognition of static and dynamic object properties by preschool children

A false recognition task was used to compare preschool children's use of static and dynamic properties of objects in semantic processing. Four, five, and six year old children heard a list of object names, and then were tested for recognition of these words with a recognition test list that included distractor words that were static or dynamic properties of the objects on the first list. False recognition scores of dynamic properties were higher than those for static, for 4 and 5 year old children, with no differences for 6 year old children. The results argue for a functional basis for the encoding of referential terms in memory, and are discussed in terms of two models of semantic development.This research was partially supported by Department of Health, Education, and Welfare Research Service Award HD 07066 and U.S. Public Health Service Grant HD 00870 from the National Institute of Child Health and Human Development to the Kansas Center for Mental Retardation and Human Development.     

Similar mechanisms underlie curvature comparison by static and dynamic touch.

In four experiments, we tested whether haptic comparison of curvature ranging from -4/m to +4/m is qualitatively the same for static and for dynamic touch. In Experiments 1 and 3, we tested whether static and dynamic curvature discrimination are based on height differences, attitude (slope) differences, curvature differences, or a combination of these geometrical variables. It was found that both static and dynamic hepatic curvature discrimination are based on attitude differences. In Experiments 2 and 4, we tested whether this mechanism leads to errors in the comparison of stimuli with different lengths for static and dynamic touch, respectively. If the judgments are based on attitude differences, subjects will make systematic errors in these comparisons. In both experiments, we found that subjects compared the curvatures of strips of the same length vertically, whereas they made systematic errors if they were required to compare the curvatures of strips of different lengths. Longer stimuli were judged to be more curved than shorter stimuli with the same curvature. We conclude that similar mechanisms underlie static and dynamic haptic curvature comparison. Moreover, additional data comparison showed that static and dynamic curvature comparison is not only qualitatively, but also quantitatively similar.     

The recognition of mental states from dynamic and static facial expressions

The ability to recognize mental states from facial expressions is essential for effective social interaction. However, previous investigations of mental state recognition have used only static faces so the benefit of dynamic information for recognizing mental states remains to be determined. Experiment 1 found that dynamic faces produced higher levels of recognition accuracy than static faces, suggesting that the additional information contained within dynamic faces can facilitate mental state recognition. Experiment 2 explored the facial regions that are important for providing dynamic information in mental state displays. This involved using a new technique to freeze motion in a particular facial region (eyes, nose, mouth) so that this region was static while the remainder of the face was naturally moving. Findings showed that dynamic information in the eyes and the mouth was important and the region of influence depended on the mental state. Processes involved in mental state recognition are discussed.     

Comparing the effects of static and dynamic signals during multiple schedules

The extent to which multiple schedules are an effective schedule thinning method following functional communication training (FCT) relies on the control the schedule-correlated stimuli exert over behavior. Thus, the stimuli used to signal the schedule in place (e.g., reinforcement and extinction) in a multiple schedule arrangement require special attention. To date, the majority of the research on multiple schedules has evaluated the use of different arbitrary signals as schedule-correlated stimuli (e.g., poster boards). These signals are considered static as they lack movement. More recently, some studies have successfully used dynamic signals, which include movement or animation, within multiple schedule arrangements. However, the extent to which one type of signal may result in faster stimulus control over behavior has not been evaluated. Thus, the purpose of this study was to compare the use of static and dynamic signals as schedule-correlated stimuli in multiple schedules used within the context of FCT. Four children diagnosed with autism spectrum disorder participated in the study. The results suggest that no differences in discriminated manding were observed for three out of four participants. Only dynamic signals resulted in discriminated manding for one participant.     

Understanding dynamic and static displays: using images to reason dynamically

We examined expert meteorologists as they created a weather forecast while working in a naturalistic environment. We examined the type of external representation they chose to examine (a static image, a sequence of static images, or a dynamic display) and the kind of information they extracted from those representations (static or dynamic). We found that even though weather is an extremely dynamic domain, expert meteorologists examined very few animations, examining primarily static images. However, meteorologists did extract large amounts of dynamic information from these static images, suggesting that they reasoned about the weather by mentally animating the static images rather than letting the software do it for them.     

Variation in perceived attractiveness: differences between dynamic and static faces

Studies that attempt to define facial attractiveness often do so in terms of structural features of the face (e.g., symmetry, averageness). However, these studies typically use static images of faces that may not be analogous to dynamic faces that are frequently used in other areas of attractiveness research, such as research investigating the impact of attractiveness on social interaction. The current studies investigated similarities and differences in how dynamic and static faces are perceived and evaluated. Study 1 demonstrated that dynamic and static faces are judged by different evaluative standards. Study 2 demonstrated that perceived emotion may be more salient in judging the attractiveness of dynamic faces than in judging the attractiveness of static faces. These findings illustrate the need to more fully explore the differences between dynamic and static faces to facilitate a better understanding of the characteristics underlying perceived attractiveness.