Necker Cube Research Articles

Depth cues of disparity and relative size added to Necker cube.

A stereogram was prepared in which one of the alternating facets of the Necker cube was drawn with uncrossed disparity and a reduced size relative to the opposite facet. During a 2-min. stereoscopic viewing period, the disparity cue and reduced-size cue did not affect the number of reversals in depth; however, the depth cues led to the disparate and smaller facet being perceived as more distant for a longer duration than the other facet.

DEPTH CUES OF DISPARITY AND RELATIVE SIZE ADDED TO NECKER CUBE

A stereogram was prepared in which one of the alternating facets of the Necker cube was drawn with uncrossed disparity and a reduced size relative to the opposite facet. During a 2-min. stereoscopi...

Smooth pursuit eye tracking and neuro-psychological performance in healthy volunteers. Exploring a possible genetic marker for vulnerability to schizophrenia.

Eye movement dysfunction (EMD) has been repeatedly found in schizophrenics and their first-degree relatives. In the present study, smooth pursuit eye tracking was measured in healthy subjects and related to performance on computerized neuropsychological tasks assumed to involve frontal or frontoparietal functions: monitoring perspective fluctuations (Necker cube), finger tapping, trail making, reaction time (RT) and a perceptual maze test. Poor trackers performed worse on tasks requiring parallel processing (trail making with letters and digits and RT with random auditory signals for response inhibition) and made more errors and cancellations on the mazes. Results are in line with our earlier EMD results on schizophrenics, showing poor performance on frontal tasks. However, their deficiency was more pervasive, whereas the present healthy EMD subjects only had difficulties with more complex tasks. The results are of interest in view of the recent evidence that EMD may be a genetic marker for vulnerability to schizophrenia.

Arrows-anchors: figure-ground reversals.

To the well known repertoire of bistable ambiguous figures (Necker cube, vases-face, Boring's «young girl-old lady», etc.) we humbly aspire to add and interesting case of bistable figure-ground reversing pattern

Performance of inattentive-overactive children on selected measures of prefrontal-type function.

Several theorists have suggested that childhood inattention-overactivity ("attention deficit disorder," "hyperactivity") may arise from a deficit in the inhibitory mechanisms of the prefrontal cortex. Accordingly, it was hypothesized that inattentive-overactive children would exhibit prefrontal-type deficits on several relevant neuropsychological measures. Subjects were 21 elementary school pupils who had been referred for disruptive behavior problems and who had been rated as high in inattention-overactivity. Controls were 26 age-matched normal children from the same school. It was found that the Inattentive-Overactive group, relative to the Control group, performed in the direction of prefrontal-type deficit on three measures that have an empirical history of discriminating patients with prefrontal lesions from controls: Perseverative errors on the Wisconsin Card Sorting Test, errors on the sequential Matching Memory Task, and Necker Cube reversals. On three theoretical indices of prefrontal-type deficit--Trailmaking, the Stroop Color-Word Test, and a sequential memory task for children--the Inattentive-Overactive group also exhibited predicted deficits. There were no differences between groups on the WISC-R Vocabulary subtest. The results of the study are generally compatible with a prefrontal-deficit theory of inattention-overactivity. However, the presence of other deficits cannot be ruled out nor can an organic cause be inferred from these findings alone.

Age and living conditions as related to perceptions of ambiguous figures.

For ambiguous figures, reversing and embedded/hidden subfigures, data were obtained from four groups of 20 subjects each varying in age (young or elderly) and living environments (in college, in the community, and in nursing homes or confined to an institution). 10 men and 10 women were tested in each of the four groups. Dependent measures were the number of reversals passively reported for the Necker cube, the Mach book, the Schroeder staircase within 90 sec. on each task, and the number of embedded/hidden figures located. Younger subjects generally saw more reversals and found more embedded figures than elderly ones. The subjects' living situation, education, and verbal ability also were correlated with perceptual performance. These results suggest generalization of age associations with scores in 90 sec. must be tempered by consideration of other factors which affect intactness, basic competence, and how competence is measured.

Reinterpreting visual patterns in mental imagery

In a recent paper, Chambers and Reisberg (1985) showed that people cannot reverse classical ambiguous figures in imagery (such as the Necker cube, duck/rabbit, or Schroeder staircase). In three experiments, we refute one kind of explanation for this difficulty: that visual images do not contain information about the geometry of a shape necessary for reinterpreting it or that people cannot apply shape classification procedures to the information in imagery. We show, that given suitable conditions, people can assign novel interpretations to ambiguous images which have been constructed out of parts or mentally transformed. For example, when asked to imagine the letter “D” on its side, affixed to the top of the letter “J”, subjects spontaneously report “seeing” an umbrella. We also show that these reinterpretations are not the result of guessing strategies, and that they speak directly to the issue of whether or not mental images of ambiguous figures can be reconstrued. Finally, we show that arguments from the philosophy literature on the relation between images and descriptions are not relevant to the issue of whether images can be reinterpreted, and we suggest possible explanations for why classical ambiguous figures do not spontaneously reverse in imagery.

Reinterpreting Visual Patterns in Mental Imagery

In a recent paper, Chambers and Reisberg (1985) showed that people cannot reverse classical ambiguous figures in imagery (such as the Necker cube, duck/rabbit, or Schroeder staircase). In three experiments, we refute one kind of explanation for this difficulty: that visual images do not contain information about the geometry of a shape necessary for reinterpreting it or that people cannot apply shape classification procedures to the information in imagery. We show, that given suitable conditions, people can assign novel interpretations to ambiguous images which have been constructed out of parts or mentally transformed. For example, when asked to imagine the letter “D” on its side, affixed to the top of the letter “J”, subjects spontaneously report “seeing” an umbrella. We also show that these reinterpretations are not the result of guessing strategies, and that they speak directly to the issue of whether or not mental images of ambiguous figures can be reconstrued. Finally, we show that arguments from the philosophy literature on the relation between images and descriptions are not relevant to the issue of whether images can be reinterpreted, and we suggest possible explanations for why classical ambiguous figures do not spontaneously reverse in imagery.

Hypnotic Susceptibility, Visual Distraction, and Reports of Necker Cube Apparent Reversals

Subjects, either susceptible (n = 50) or resistant (n = 50) to hypnotic suggestion, were asked to report on frequency of apparent reversals (ARs) to the Necker cube illusion. Such reports were made in the presence or absence of various types of visual, geometric surrounds (squares, triangles, crosses, or parallelograms). In agreement with a number of previous experiments, susceptible subjects reported perceiving more ARs than did resistant subjects. This difference held whether visual surrounds were present or absent. The presence of surrounds did serve to reduce AR reports regardless of hypnotic susceptibility level. The results are examined in terms of the ability of subjects to selectively attend when confronted with potential visual distractors.

Hemispheric dominance inferred from Your Style of Learning and Thinking on reports of Necker cube reversals and maze learning.

30 subjects volunteered from three sources: community adults (M age = 32.8, SD = 13.4), college adults (M age = 23.8, SD = 8.3), and children (M age = 9.5, SD = 1.7) and were categorized as 'left-' and 'right-dominant' by scores on Your Style of Thinking and Learning. They reported the number of Necker cube reversals perceived in 90 sec., attempted to locate four embedded figures, and blindly traversed a 16-choice point finger maze in that order. 'Right-dominant' subjects located more embedded figures and made fewer errors on the finger maze than did 'left-dominant' subjects. College adults reported more Necker cube reversals than did community adults and children, and community adults reported more reversals than did children. Confounds of performance measures with fatigue and/or practice require further research.

Determinants involved in the perception of the Necker cube: an application of catastrophe theory.

The study is concerned with evaluating interactions at the organic level within the visual perception subsystem of living systems. The reported work focuses on the identification of some of the determinants of multistable perception by experimentally testing a nonlinear dynamical systems (catastrophe) model of the Necker Cube. This technique serves as an advantage over linear threshold models which cannot effectively study multivalued functional relationships. It was proposed that manipulation of two independent control parameters (bias or changing shape by continuously varying perspective lines and selective stimulus shading) was compatible with the subjective dichotomy of bistable perception of the Necker cube. One hundred and twenty naive subjects, categorized by age, sex, and optical aids, were presented with a computer-generated sequence of 63 stimuli (7 shading levels X 9 perspective levels) to which they had to respond as to whether they saw a "hollow" or "solid" image. The work revealed that bias and shading exerted their effects in opposition and that each influenced the other. Both were decisive factors involved in the perception of the cube. These findings are supported by topological and psychological evidence.

Selective adaptation vs. transfer of decrement: the conjoint effects of neural fatigue and perceptual learning.

Statement of Problem In the last few years, my colleagues and I have been interested in the processes underlying the perceived reversals of reversible figures (Long & Toppino, 1981; Long, Toppino, & Kostenbauder, 1983; Toppino & Long, 1987). One ofthe approaches we have used in our work is the popular selective-adaptation paradigm as a means by which to identify the potential role in this type of illusion of localized neural mechanisms that are subject to fatigue. In this method, an inspection figure is viewed during an adaptation period of perhaps 2-3 min, and a test figure is then shown which shares certain hypothesized features with the adaptation figure. To the extent that the prior adaptation alters the perception of the test figure, one can conclude that similar localized mechanisms are involved in the perception of both figures. This selectiveadaptation paradigm has proven extremely powerful in the investigation of numerous illusions, such as the tilt aftereffect, the motion aftereffect, and the size aftereffect. Reflecting its current popularity, the selective-adaptation paradigm has been referred to as the psychologist's electrode (Frisby, 1980) with which to probe the tuning and response characteristics of hypothesized neural channels in the visual system (e.g., Regan, 1982). In our work, we have attempted to demonstrate the role of localized fatigue effects on the reported reversals of the rotating Necker cube. In this illusion, a threedimensional Necker cube frame is rotated about one of its vertices at a constant speed. An observer viewing either the cube itself or its shadow reports a striking change in the perceived direction of rotation when the cube changes its perspective. As with other reversible figures, the number of reported reversals increases and then levels off at a high rate during a 2-3-min viewing period. For several reasons, we (and others) have proposed that this changing reversal rate reflects fatigue effects in particular visual channels; in our work, we have attempted to demonstrate the limited (i. e., local) character of this fatigue by means of the selective-adaptation paradigm. In one recent experiment (Toppino & Long, 1987, Experiment 1), a rotating cube in the left (or right) visual field was viewed for a 2-min adaptation period, which was followed immediately by a 2-min test period with a cube in the same or

Visual evoked potentials to illusory reversals of the necker cube.

ABSTRACTSensory adaptation and cognitive evaluation have been proposed as explanations of illusory figure reversals. The effect of variations in the perceived orientation of a Necker cube on visual evoked potentials (VEPs) was studied to test these two hypotheses. VEPs associated with perceptual reversals and non‐reversals of a Necker cube were compared with VEPs elicited by a sequence of physically varying cubical figures. Amplitude differences in the early VEP components consistent with adaptation effects were not detected. Both types of reversals were associated with a late positive component (400–700 ms), which was smaller in amplitude in the illusory condition. The late positivity to illusory reversals was also distinguished by a broad (200–700 ms) positive component over frontal and central recording sites which was absent over Oz. These findings suggest that illusory reversals are more difficult to discriminate than physical reversals, and require additional cognitive resources for evaluation.

Psychiatry and the Necker Cube. Neurological and Psychological Conceptions of Psychiatric Disorder

Neurological and psychological conceptions of psychiatric disorder are in conflict at the present time. This conflict is considered in the context of the history of psychiatry and the philosophy of science. Its practical consequences are considered for the motor disorder of schizophrenia, the cognitive impairment in psychiatric illnesses, the use of the terms organic and functional and the association of neurological disorder with psychotic and neurotic disorders. The conflict is also examined in individual cases and the implications for treatment assessed.

Psychiatry and the necker cube. Neurological and psychological conceptions of psychiatric disorder.

Neurological and psychological conceptions of psychiatric disorder are in conflict at the present time. This conflict is considered in the context of the history of psychiatry and the philosophy of science. Its practical consequences are considered for the motor disorder of schizophrenia, the cognitive impairment in psychiatric illnesses, the use of the terms organic and functional and the association of neurological disorder with psychotic and neurotic disorders. The conflict is also examined in individual cases and the implications for treatment assessed.

Viewing direction and pictorial representation.

During prolonged monocular observation from afar, an upright wire cube (Necker cube) or a drawing of such a cube inverts continuously so that the lower of the two frontal faces appears to be either in front (version A) or in back (version B). Version A is perceived as if it were viewed obliquely from above and version B as if seen from below. In our experiments, timing the durations of the versions showed that version A lasted longer than version B. When a wire cube was shifted upward so that it was actually viewed slightly from below, version B lasted longer than version A. The actual viewing direction was apparently taken into account by the subjects, which was not the case when the cube was replaced by a drawing showing the projection of the cube. In that case, version A always lasted longer, regardless of the actual viewing direction. This finding conforms with picture viewing in general, where a three-dimensional object’s orientation does not change when the observer’s viewing direction changes.

Interpretive process of depth in line drawing

AbstractThe Necker cube is a line drawing having two possible solutions in depth perception. The process of interpreting a two‐dimensional line drawing as a three‐dimensional object was investigated using the Necker cube. Attention was directed to a local feature of a briefly presented cube, i.e., an angle at a vertex. The angle under observation was perceived as a front part of the cube and other parts were interpreted so as to match the interpretation of the angle pattern. Results show that the local feature to which attention was directed, was interpreted first. Then global features and other local features were interpreted so as to agree with the local feature interpreted initially. This suggests that the three‐dimensional interpretation of the line drawing was made sequentially from the local feature to global structures.

Selective adaptation with reversible figures: don't change that channel.

An adaptation-test paradigm was used in two experiments examining processes underlying the perceived reversals of a rotating Necker cube. Adaptation and test cubes were either the same or different with respect to their visual fields of presentation (Experiment 1) or their sizes (Experiment 2). Results of both experiments indicated that, following subjects’ adaptation to a different cube, reversal rate of the test cube did not differ from that obtained without prior adaptation experience. In contrast, reversal rate of the test cube was elevated following adaptation to the same cube. Additional findings of Experiment 1 were that a test cube presented to the same visual field as the adaptation cube yielded a higher reversal rate than did a simultaneously presented cube in the opposite visual field. Also, the reversal rate of one cube was not influenced by the simultaneous presentation of a second cube. Results of both experiments were interpreted in terms of the fatigue and recovery of multiple, largely independent, localized neural channels. Thus, the results tie reversible-figure illusions to other visual phenomena thought to involve similar fatigue processes within localized visual channels (e.g., tilt, motion, and size aftereffects).

Perspective vergence: oculomotor responses to line drawings.

When a perspective drawing is viewed monocularly, changes in fixation point are accompanied by changes in steady-state vergence; their direction is usually appropriate for the distance relationships implied in the illustration. The absolute magnitude of these responses varies appreciably among subjects; it can be consistently enhanced or reduced by modest changes in the drawing. Similar configurations of stimuli from three-dimensional objects would presumably also contribute to normal vergence movements during binocular viewing; it appears that their importance would increase with target distance. Corresponding changes in pupil diameter, as expected for the "near reflex", were not observed with perspective stimuli. Consistent, directionally appropriate vergence changes, paralleling perception, were also made by most subjects during monocular viewing of a Necker cube, but there, exceptionally large pupillary responses arose.

DC potential shift preceding repetitive perceptually relevant stimuli and its possible origin

The Necker cube patterm was flashed repetitively with regular 5.12 s interstimulus intervals and EEG activity was recorded by means of non-polarizable Ag/AgCI electrodes and averaged. The subjects reported the actual subjective interpretation of the pattern by pushing one of two buttons, i.e. they were motivated to interpret each stimulus. A negative potential shift (lasting about 2.5 s increasing in a more or less linear way and, reaching the final amplitude of about 11 mV), developed gradually before the stimulus onset. Positive correlation was found between the duration and amplitude of DC shift. The phenomenon described might reflect cortical processes related to expectation of a regularly repeated perceptually relevant stimulus and may be considered a version of CNV. A hypothesis interpreting the DC shift as the consequence of neuroglial processes is presented.