How to keep a reversible figure from reversing: teasing out top-down and bottom-up processes

The nature of processes underlying our perception of reversible figures was examined through two experiments investigating the effects of prior exposure conditions on an observer's report of figural reversal. In experiment 1, observers were adapted over several minutes to an unambiguous version of a rotating Necker cube prior to the presentation of the standard ambiguous figure. Results indicated that adaptation produced an immediate bias to perceive the ambiguous figure in the opposite configuration (ie reverse bias) and to reduce reports of reversal over the test period. The introduction of a brief delay between the adaptation and test periods revealed that this bias is a highly transient effect and is only clearly evident when the adaptation and test figures are matched in size. In experiment 2, observers were primed with an unambiguous figure for a few seconds prior to the presentation of the standard ambiguous figure. In this case, the obtained bias strongly favored the observer's reporting the ambiguous figure to be in the same configuration as the adapting figure (ie positive bias); and neither introducing a delay period nor changing figure size had any effect. We conclude that these experiments reveal the distinct roles of transient, retinally localized neural processes as well as more stable, global processes under specifiable conditions.     

Adaptation effects and reversible figures: A comment on Horlitz and O’Leary

In a recent article, Horlitz and O’Leary (1993) offer a reinterpretation of the results of several studies over the past 40 years that have employed the prolonged-inspection technique in the investigation of reversible figures. Specifically, they contend that, contrary to the favored interpretation of neural adaptation effects, the results of these studies reveal the combined influence of such topdown processes as attention and perceptual learning as well as such methodological difficulties as unwanted demand characteristics. In this note, we examine their analysis of the literature, their alternative theoretical model, and the supporting conclusions they draw from their two experiments. We argue that there is considerable evidence from a variety of studies for the joint role of bottom-up and top-down processes in reversible figures. Moreover, we propose that Horlitz and O’Leary’s own research, rather than eliminating the possibility of neural-adaptation effects, is best conceptualized as providing additional evidence for the role of higher-order processes in these phenomena.     

Viewpoint-dependent recognition of familiar faces

The question whether object representations in the human brain are object-centered or viewer-centered has motivated a variety of experiments with divergent results. A key issue concerns the visual recognition of objects seen from novel views. If recognition performance depends on whether a particular view has been seen before, it can be interpreted as evidence for a viewer-centered representation. Earlier experiments used unfamiliar objects to provide the experimenter with complete control over the observer's previous experience with the object. In this study, we tested whether human recognition shows viewpoint dependence for the highly familiar faces of well-known colleagues and for the observer's own face. We found that observers are poorer at recognizing their own profile, whereas there is no difference in response time between frontal and profile views of other faces. This result shows that extensive experience and familiarity with one's own face is not sufficient to produce viewpoint invariance. Our result provides strong evidence for viewer-centered representations in human visual recognition even for highly familiar objects.     

Differences in top-down influences on the reversal rate of different categories of reversible figures

Understanding the mechanisms underlying the multistability of reversible figures may provide valuable insights into the normal functioning of our visual system. The proposed factors that control the perceptual alternations of reversible figures can be classified into bottom-up and top-down processes. In the present study, we report differences in top-down effects on the reversal rate depending on whether a structural perspective (Necker cube, Schr?der staircase) or a meaningful content (duck/rabbit figure, chef/dog figure) is subject to the reversal phenomenon. In order to activate top-down mechanisms explicitly the subjects had the instruction to bring the reversal rate under voluntary control. The results indicated that both slowing down and speeding up the rate of alternations was more effective for the content-reversal figures (duck/rabbit, chef/dog) than for the rather abstract perspective-reversal figures (Necker cube, Schr?der staircase). In order to investigate the effect of meaningfulness in figure/ground reversals, the effect of the same instructional variable was also determined for Rubin's vase/faces and the Maltese cross. The results showed a similar tendency as in the case of the comparison between perspective reversals and content reversals. Possible cognitive processes that may play a role in top-down influences on figure reversal and theoretical implications of these findings for the interaction of bottom-up and top-down processes are discussed.     

Hierarchical structure in perceptual representation

A theoretical framework for perceptual representation is presented which proposes that information is coded in hierarchical networks of nonverbal propositions. The hierarchical structure of the representations implies selective organization: Some subsets of a figure will be encoded as integral, structural units of that figure, while others will not. A context-sensitive metric for the “goodness” of a part within a figure is developed, corresponding to the probability that the subset will be encoded as a structural unit. Converging evidence supporting this position is presented from four different tasks using simple, straight-line figures. The tasks studied are (a) dividing figures into “natural” parts, (b) rating the “goodness” of parts within figures, (c) timed verification of parts within figures, and (d) timed mental synthesis of spatially separated parts into unitary figures. The results are discussed in terms of the proposed theory of representation, the processes that operate on those representations, and the general implications of the data for perceptual theories.     

Assessing the effects of audiovisual semantic congruency on the perception of a bistable figure

Bistable figures provide a fascinating window through which to explore human visual awareness. Here we demonstrate for the first time that the semantic context provided by a background auditory soundtrack (the voice of a young or old female) can modulate an observer's predominant percept while watching the bistable "my wife or my mother-in-law" figure (Experiment 1). The possibility of a response-bias account-that participants simply reported the percept that happened to be congruent with the soundtrack that they were listening to-was excluded in Experiment 2. We further demonstrate that this crossmodal semantic effect was additive with the manipulation of participants' visual fixation (Experiment 3), while it interacted with participants' voluntary attention (Experiment 4). These results indicate that audiovisual semantic congruency constrains the visual processing that gives rise to the conscious perception of bistable visual figures. Crossmodal semantic context therefore provides an important mechanism contributing to the emergence of visual awareness.     

Constructing representations of spatial location from briefly presented displays

Spatial memory and reasoning rely heavily on allocentric (often map-like) representations of spatial knowledge. While research has documented many ways in which spatial information can be represented in allocentric form, less is known about how such representations are constructed. For example: Are the very early, pre-attentive parts of the process hard-wired, or can they be altered by experience? We addressed this issue by presenting sub-saccadic (53 ms) masked stimuli consisting of a target among one to three reference features. We then shifted the location of the feature array, and asked participants to identify the target’s new relative location. Experience altered feature processing even when the display duration was too short to allow attention re-allocation. The results demonstrate the importance of early perceptual processes in the creation of representations of spatial location, and the malleability of those processes based on experience and expectations.     

To reverse or not to reverse: when is an ambiguous figure not ambiguous?

The role of bottom-up processes in our perception of reversible figures was examined. In Experiment 1 the overlapping squares figure and nonsense reversible figures were used. The effects of adapting subjects for differing durations to an unambiguous version of the figure before presentation of the traditional reversible figure were determined under conditions of varying precision of fixation. In Experiment 2 the research was expanded to other examples of reversible figures. In both experiments, results with two dependent measures (the subject's first percept and the number of reversals reported) were generally consistent with the interpretation of bottom-up processes underlying the adaptation effects. However, the crucial role of stimulus and procedural variables and the differential sensitivity of the two dependent measures was demonstrated.     

Framing the figure: Mental rotation revisited in light of cognitive strategies

The mental rotation literature commonly reports a sex difference, almost always favoring men. Two strategies have been proposed in the literature to account for this difference: holistic and piecemeal. However, there is great variability in rotation performance suggesting other possible contributing factors. This study investigated the effects of stimuli characteristics and habitual spatial thinking on mental rotation performance. In three experiments, participants completed a mental rotation task with two modifications: (1) 3-D figures were presented with their cut versions to promote piecemeal strategy, and (2) block figures were either presented within a frame or none, in light of reference framework model or perceptual grouping model. Overall, whole figures generated faster responses than cut figures and this was more pronounced with greater angular disparity. Shape or the presence of a frame affected rotation performance. Having a frame seemed to impede overall rotation, especially for cut figures, supporting an object-based reference frame. However, a 3-D frame did not have the same effect, possibly suggesting the unitary configuration idea. Men rotated more accurately than women, but still sex was not as robust as it was suggested in the literature. Interestingly, there were similarities between possible strategy use and habitual spatial thinking. People who were categorized as having landmark-centered representations and who preferred verbal directions showed a pattern suggesting the use of a piecemeal strategy, and survey-centered representations and map preference seemed to reflect a holistic strategy.     

Duck or rabbit? Reversing ambiguous figures and understanding ambiguous representations

In two studies we investigated 3‐ to 5‐year‐old children’s ability to reverse ambiguous figures and the relation between this ability and the ability to understand multiple representations. Children never reversed before they were informed of the two alternative interpretations of the figures. Even when they were informed of the alternatives and understood that both were possible, 3‐year‐olds and most 4‐year‐olds did not reverse. In contrast, a majority of 5‐year‐olds did reverse. In general, children only reversed if they also passed a standard false belief task. However, there was a closer correlation between reversals and a ‘droodle’ task that involved an understanding of the ambiguity of perceptual representations. These results suggest that the immediate experience of reversal may depend on a more abstract understanding of ambiguous representations.     

Social representations of smoking and attitudes towards smoking restrictions in the Norwigian Navy

The present study investigated the relationship bewteen social representations about smokers and smoking, and attitudes towards smoking restrictions. Data were collected by means of questionnaires among a sample of employees ( n =4224)in the Norwegian Navy. Based on the results from first- and second-order principal components analyses, three dimensions of social representations were identified. The dimensions were labeled "negative representations", "positive representations" and "social influence". The three dimensions clearly differentiated between daliy, occasional and non-smokers. Further, structural equation modeling of the relation between social representations and attitudes towards smoking restrictions, indicated that social representations function as intermediating factors of the effect from smoking states upon attitudes towards smoking restrictions.
The findings indicate the need to focus upon social psyshological processes taking place in the ineraction between groups of smokers and non-smokers, as understanding of such processes may be relevant in preventing the development of group conflict.     

儿童对观察者预期造成的模糊刺激解释多样性的理解

研究考察6~8岁儿童在由观察者预期造成的对模糊信息有多样解释上的理解.操纵影响观察者预期的因素,包括知觉经验、知识水平、先前经历和偏见,要求儿童预测观察者对局限视野图形或两可动作信息的解释.结果表明,6岁儿童仅对观察者偏见影响其对行动者行为的解释拥有部分理解,他们还不能理解知觉经验和知识水平会影响观察者对视觉刺激的解释,以及先前经历会影响观察者对行动者行为的解释.7岁儿童除了知识水平外,其它三方面的理解都已发展起来.8岁儿童可以理解多种观察者预期造成的解释差异,解释性心理理论比较稳定,但离完全成熟的理解还有一段距离.     

What Do Implicit Measures Tell Us? Scrutinizing the Validity of Three Common Assumptions

ABSTRACT— Experimental paradigms designed to assess "implicit" representations are currently very popular in many areas of psychology. The present article addresses the validity of three widespread assumptions in research using these paradigms: that (a) implicit measures reflect unconscious or introspectively inaccessible representations; (b) the major difference between implicit measures and self-reports is that implicit measures are resistant or less susceptible to social desirability; and (c) implicit measures reflect highly stable, older representations that have their roots in long-term socialization experiences. Drawing on a review of the available evidence, we conclude that the validity of all three assumptions is equivocal and that theoretical interpretations should be adjusted accordingly. We discuss an alternative conceptualization that distinguishes between activation and validation processes.     

Seeing while acting: hand movements can modulate attentional capture by motion onset

The onset of new motion has been shown to be a very robust cause of attentional capture, generating a processing advantage for the location of motion onset regardless of the observer's concurrent goal. The present study, motivated by the common-coding account of action and perception, examined whether the effect of motion onset on visual attention can be modulated by the observer's mode of action. Specifically, the common-coding account predicts that preparing an action can render the features that are used in the action plan less available for visual processes. Consistent with this hypothesis, in Experiment 1 the magnitude of attentional capture caused by a single motion onset was reduced when this motion was similar to the observer's response (i.e., along the same axis). Similarly, in Experiment 2 the onset of a response-different motion gained a processing advantage over the response-similar motion onset when the two were presented simultaneously. Since both types of motion were present in every trial, the results of Experiment 2 suggest that response similarity affected visual-attentional processes rather than motor processes. Together, these results suggest that the processes of attentional prioritization caused by motion onset can be modulated by the observer's concurrent action.     

Reversible-figure perception: mechanisms of intentional control

Observers can exert a degree of intentional control over the perception of reversible figures. Also, the portion of the stimulus that is selected for primary or enhanced processing (focal-feature processing) influences how observers perceive a reversible figure. Two experiments investigated whether voluntary control over perception of a Necker cube could be explained in terms of intentionally selecting appropriate focal features within the stimulus for primary processing. In Experiment 1, varying observers' intentions and the focus of primary processing produced additive effects on the percentage of time that one alternative was perceived. In Experiment 2, the effect of varying the focus of primary processing was eliminated by the use of a small cube, but the effect of intention was unaltered. The results indicate that intentional control over perception can be exerted independently of focal-feature processing, perhaps by top-down activation or priming of perceptual representations. The results also reveal the limits of intentional control.     

The self-organizing consciousness

We propose that the isomorphism generally observed between the representations composing our momentary phenomenal experience and the structure of the world is the end-product of a progressive organization that emerges thanks to elementary associative processes that take our conscious representations themselves as the stuff on which they operate, a thesis that we summarize in the concept of Self-Organizing Consciousness (SOC).     

Failure to construct and transfer correct representations across probability problems

Previous studies carried out on "purely random" situations (with dice or poker chips) show the difficulties encountered by people in such situations, however simple they may be. In fact, in this type of situation, prior knowledge guides spontaneous representations, and the "errors" observed could be explained by the activation of "implicit models" which form the basis of erroneous representations. 42 statistically na?ve undergraduates were given several variants of a probability problem on which errors are common. In a learning phase, subjects were given four problems involving geometric figures which were pairwise related by complementarity and equivalence relations. In a subsequent transfer phase, they were given a fifth problem involving poker chips, which was structurally isomorphic to the fourth geometric-figures problem. The findings show that people do not realize the relations between problems, and that transfer occurred only for the subset of subjects who performed correctly on the training problems of the learning phase. These results appear to have some significant implications in teaching mathematical concepts.     

Oscillatory gamma activity in humans and its role in object representation

We experience objects as whole, complete entities irrespective of whether they are perceived by our sensory systems or are recalled from memory. However, it is also known that many of the properties of objects are encoded and processed in different areas of the brain. How then, do coherent representations emerge? One theory suggests that rhythmic synchronization of neural discharges in the gamma band (around 40 Hz) may provide the necessary spatial and temporal links that bind together the processing in different brain areas to build a coherent percept. In this article we propose that this mechanism could also be used more generally for the construction of object representations that are driven by sensory input or internal, top-down processes. The review will focus on the literature on gamma oscillatory activities in humans and will describe the different types of gamma responses and how to analyze them. Converging evidence that suggests that one particular type of gamma activity (induced gamma activity) is observed during the construction of an object representation will be discussed.     

The Goal Circuit Model: A Hierarchical Multi‐Route Model of the Acquisition and Control of Routine Sequential Action in Humans

Human control of action in routine situations involves a flexible interplay between (a) task‐dependent serial ordering constraints; (b) top‐down, or intentional, control processes; and (c) bottom‐up, or environmentally triggered, affordances. In addition, the interaction between these influences is modulated by learning mechanisms that, over time, appear to reduce the need for top‐down control processes while still allowing those processes to intervene at any point if necessary or if desired. We present a model of the acquisition and control of goal‐directed action that goes beyond existing models by operationalizing an interface between two putative systems—a routine and a non‐routine system—thereby demonstrating how explicitly represented goals can interact with the emergent task representations that develop through learning in the routine system. The gradual emergence of task representations offers an explanation for the transfer of control with experience from the non‐routine goal‐based system to the routine system. At the same time it allows action selection to be sensitive both to environmental triggers and to biasing from multiple levels within the goal system.