Eye movement as a cue to figure motion in anorthoscopic perception

When a figure moves behind a narrow aperture in an opaque surface, if it is perceived as a figure, its shape will often appear distorted. Under such anorthoscopic conditions, the speed or direction of the object's motion is ambiguous. However, when the observer simultaneously tracks a moving target, a figure is always perceived, and its precise shape is a function of the speed or direction of tracking. The figure is seen as moving with the speed or in the direction of the target. Thus, it is argued that eye movement serves as a cue to the figure's motion, which, in turn, determines its perceived length or orientation.     

Reprocessing as a recognition cue

The use of mental operations as recognition cues was investigated. Two experiments support the hypothesis that processing details are retained in memory and that a re-creation of those processing details can effectively cue recognition. Four subjects performed a mental arithmetic task that emphasized speed and accuracy while discouraging memorization of the numbers. Recognition was cued either by single numbers or by a pair of numbers that, when added, replicated an episode of the original task. Reprocessing an episode was the most effective recognition cue. Of the two single-number cues, the intermediate subtotals were recognized, whereas the numbers that had been physically displayed were not. The study suggests: (1) that the sequence of mental operations is retained in memory, (2) that reprocessing uses this trace to facilitate performance, and (3) that the detection of facilitated reprocessing aids recognition.     

Pitch as a phonemic cue

Three experiments that were designed to determine how pitch information is represented in auditory memory are reported. A same-different reaction time was used in all three experiments. Previous experiments have interpreted the finding of faster “same” responses to acoustically identical pairs than to pairs that are phonemically identical but acoustically distinct as indicating that there is a memory that preserves auditory information. It has been assumed that this can be used to match “same” pairs only if the formant frequencies of the members of the pair are the same. In the first experiment, the size of this matching advantage for pairs with identical formant frequencies was not altered when the members of the pair were on different pitches. This indicates that pitch is represented separately from the formants at the auditory level. The second and third experiments used a bigger pitch difference when the pairs were on a different pitch, which, for one of the stimulus sets, resulted in a change in vowel quality but not in the identity of the consonant. In the other stimulus set, both phonemes of the syllable remained the same when presented on different pitches. The matching advantage was reduced when the stimuli were on different pitches for both stimulus sets. This indicates that a difference in pitch can prevent matching at the auditory level under some circumstances. An additional finding, a reduced residual matching advantage when the syllable changes, indicates that at least a syllable-length representation is held in auditory memory. The results are discussed with respect to how the representation in auditory memory might be used in the perception of speech produced by different speakers.     

Perceived common rotary motion of ambiguous stimuli as a criterion of perceptual grouping

Apparent common behavior of contours with respect to a property for which each contour is ambiguous (in this case direction of rotary motion in depth) was used as a criterion of the unitary processing of the contours or “grouping.” Grouping was found to decrease as a monotonic function of the difference in line orientation and, for fixed orientations, to decrease as a monotonic function of line separation. These results are tentatively attributed to the distribution of line detectors in the projection area.     

Perceived rotary motion from changes in a straight line

The problem dealth with was how perception of a three-dimensional space is related to the corresponding two-dimensional retinal image. The stimulation used was a straight line changing length and direction. For this stimulation a geometrical model was developed. The basic decoding principle in this model is that the changes in the two-dimensional figure will be perceived as three-dimensional motions of an object with constant shape and size. This principle was approximately verified for the majority of the data. The main deviation from the model was that there was generally less perceived depth than predicted. Also a second decoding principle was generally verified: rotary, but not translator motion is perceived from this kind of stimulation. A third unexpected decoding principle was found in the data: the line is perceived in a frontal-parallel direction when it has its maximal extention.     

Convergence as a cue to depth

A test that presents conflicting monocular and vergence cues to depth shows that approximately two-thirds of the population can use convergence as a cue to depth. The remaining one-third apparently cannot use this cue. These differences in the role of convergence in depth perception reflect individual differences in the neural mechanisms underlying depth perception.     

Anger as a cue to truthfulness

A fairly robust finding in the deception literature is that lie-tellers show more negative emotion than truth-tellers. Ekman (1985), however, has reasoned that a specific type of negative emotion - anger - is especially difficult to feign and therefore should be more prevalent in truth-tellers who are falsely accused of a transgression than in lie-tellers who are guilty. To our knowledge, Ekman’s prediction has not yet been empirically tested. By comparing the verbal and nonverbal cues associated with truths and lies across a number of lie-eliciting situations, we demonstrate that truth-tellers accused of a wrongdoing do show more anger, both verbally and nonverbally, than lie-tellers accused of the same act, but only in situations where students choose to commit a transgression (or not) and actually believe themselves to be in trouble. Results underlie the importance of taking into consideration the type of lie being told in order to accurately predict deceptive cues.     

The use of perspective as a depth cue with a 2D display in 4 and 5-month-old infants

Four experiments were conducted to study the use of perspective as a depth cue in infants, using an eye-tracking-system. In the first experiment, no significant difference was observed between the looks for the "normal" and the "strange" events on the complete display and at the target in 4-month-olds. In the second experiment, the results of 5-month-olds were similar to those obtained by 4-month-olds but they looked more at the test events when the "strange" event was presented first. In the third experiment, 5 month-olds were shown a repeated presentation adapted from the "Partial-Lag" design. Infants' exploration of the target indicated that they looked more at the "strange" event than at the "normal" event. In the fourth experiment, the same design was used with 4-month-olds but no difference between conditions was observed. Five-month-olds seem to be able to use the perspective cues alone. These different data are discussed.     

Disturbance cues function as a background risk cue but not as an associative learning cue in tadpoles

Animal Cognition - Chemical information has an important role in the sensory ecology of aquatic species. For aquatic prey, chemical cues are a vital source of information related to predator...     

The misperception of rotary motion

Two principles for predicting the relative frequency of illusory reversals of rotating plane objects were derived and tested empirically. Ten objects, variously’ combining valid and confounding depth cues, were used. Predictions based on the principles were confirmed in every case. The results are offered as an improved explanation of the Ames trapezoid illusion and other illusions of rotary motion.     

Perceived direction of rotary motion

The starring point for this study was the rotating trapezoidal window. The aim was to reanalyze the problem of information about direction of rotation that is available in simplified proximal stimulations and to study empirically if the Ss utilized the possibilities demonstrated in the theoretical analyses. These analyses showed that a distal poin t moving in a horizontal circular path gives different proximal stimulations when moving clockwise and counterclockwise Further, a distal vertical line moving with its midpoint in the same path has a proximal change of length with different phase relations with the horizontal back-and-forth motion for the two directions. The proximal stimulation is ambiguous, however, unless some restrictions or “decoding principles” are introduced. In the first two experiments it was shown that the Ss could not report “correct” direction of motion of the point but were able to do so about the vertical line. In a third experiment a second vertical line was introduced. This necessitates a determination of relative distance to the two lines. It was shown that the proximally shorter line was usually perceived further away than the proximally longer one. The results are discussed with reference to the trapezoidal window. and some hypotheses are stated.     

Audience response as a heuristic cue in persuasion

Previous research on the persuasive impact of an overheard audience has yielded conflicting results. In this study, we attempted to understand such audience effects within the framework of the heuristic model of persuasion. Subjects listened to an audiotaped persuasive message that conveyed arguments of either high or low quality and that was responded to by either an enthusiastic or an unenthusiastic overheard audience. In addition, subject involvement (high vs. low) was varied. Consistent with predictions, the audience response cue influenced postmessage opinions only under low involvement; under high involvement, only argument quality affected persuasion. Analyses that took into account subjects' need for cognition supported the additional hypothesis that individuals lower in need for cognition would be more responsive to the audience manipulation under low involvement. Thought-listing data and regression analyses provided further support for the heuristic model.     

Motion as a cue for viewpoint invariance

Natural face and head movements were mapped onto a computer rendered three-dimensional average of 100 laser-scanned heads in order to isolate movement information from spatial cues and nonrigid movements from rigid head movements (Hill & Johnston, 2001). Experiment 1 investigated whether subjects could recognize, from a rotated view, facial motion that had previously been presented at a full-face view using a delayed match to sample experimental paradigm. Experiment 2 compared recognition for views that were either between or outside initially presented views. Experiment 3 compared discrimination at full face, three-quarters, and profile after learning at each of these views. A significant face inversion effect in Experiments 1 and 2 indicated subjects were using face-based information rather than more general motion or temporal cues for optimal performance. In each experiment recognition performance only ever declined with a change in viewpoint between sample and test views when rigid motion was present. Nonrigid, face-based motion appears to be encoded in a viewpoint invariant, object-centred manner, whereas rigid head movement is encoded in a more view specific manner.     

Slope of regard as a distance cue

It is proposed that some distance cues are learned when a perceptual parameter that varies with observation distance is regularly associated with objects whose distances are perceived because another distance cue operates. If that is the way distance cues can come into existence, it may be possible to identify a parameter that varies with distance but is not a known distance cue and to show that it functions as one. The slope of regard with which an object on the ground is viewed is such a potential distance cue. Its angle varies approximately with the reciprocal of distance. An experiment was done that showed that this slope angle functions as a distance cue. Subjects who looked through a device that altered slope angles gave estimates of the dimensions of an object on the ground. Perceived sizes, which vary inversely with distance, were found to be altered in accordance with the altered slope angle.