The independence of size perception and distance perception.

Research on distance perception has focused on environmental sources of information, which have been well documented; in contrast, size perception research has focused on familiarity or has relied on distance information. An analysis of these two parallel bodies of work reveals their lack of equivalence. Furthermore, definitions of familiarity need environmental grounding, specifically concerning the amount of size variation among different tokens of an object. To demonstrate the independence of size and distance perception, subjects in two experiments were asked to estimate the sizes of common objects from memory and then to estimate both the sizes and the distances of a subset of such objects displayed in front of them. The experiments found that token variation was a critical variable in the accuracy of size estimations, whether from memory or with vision, and that distance had no impact at all on size perception. Furthermore, when distance information was good, size had no effect on distance estimation; in contrast, at far distances, the distances to token variable or unknown objects were estimated with less accuracy. The results suggest that size perception has been misconceptualized, so that the relevant research to understand its properties has not been undertaken. The size-distance invariance hypothesis was shown to be inadequate for both areas of research.     

Dichotic perception and laterality in neonates

Groups of 4-day-old neonates were tested for dichotic discrimination and ear differences with the High-Amplitude-Sucking procedure. In the first experiment, dichotic speech discrimination was attested by comparison with a control group. Furthermore, among those subjects who showed a substantial recovery of sucking response at least after one of the two syllable changes, it was observed that significantly more subjects manifested a stronger reaction to a right-ear change than to a left-ear change. In the second experiment, 4-day-old neonates were tested on syllable and music timbre discrimination. The significant Stimulus Type x Ear interaction observed suggests perceptual asymmetries indicative of very precocious brain specialization.     

Bilateral tachistoscopic perception, handedness, and laterality.

Right-handed, familial left-handed, and nonfamilial left-handed males and females reported high- or low-imagery words which were located to the left and right of fixation in bilateral tachistoscopic displays. On each trial, an arrowhead appeared in the center of the display. The arrowhead pointed to either the left or the right half-field, indicating the order of report. Right-handers reported more accurately from the right half-field, and familial left-handers reported more accurately from the left half-field. The order of report results showed that right-handers were similar to nonfamilial left-handers; for left half-field presentation, both groups were more accurate when the arrowhead pointed to the left than when it pointed to the right (i.e., first report was more accurate than second report). There was a main effect of word imagery, but this factor did not interact with visual half-field. Thus, there was no evidence that representations of high-imagery words are lateralized differently than representations of low-imagery words. The results are discussed with respect to lateralization of memory for verbal material.     

Attitude and the perception of faces

To assess the effects of affective orientation on the judgment of facial attriutes, 165 subjects were asked to make judgments of the attributes of each of two faces. For each face, subjects were either given no information about the person in the photo, or were given biographical information connoting either a favorable or unfavorable personality. It was predicted that when subjects make judgments along dimensions that were evaluatively loaded (e.g., smilling vs frowning mouth), manipulated attitude would influence these judgments. For the seven dimensions rated by the subjects, four dimensions showed the predicted effect. The other three dimensions, which did not show the effect, were the only ones that showed a significant effect due to the face itself. It was concluded that for dimensions that are not highly structured by the characteristics of the face, attitude can significantly influence judgments of facial attributes.     

The independence of size perception and distance perception

Research on distance perception has focused on environmental sources of information, which have been well documented; in contrast, size perception research has focused on familiarity or has relied on distance information. An analysis of these two parallel bodies of work reveals their lack of equivalence. Furthermore, definitions of familiarity need environmental grounding, specifically concerning the amount of size variation among different tokens of an object. To demonstrate the independence of size and distance perception, subjects in two experiments were asked to estimate the sizes of common objects from memory and then to estimate both the sizes and the distances of a subset of such objects displayed in front of them. The experiments found that token variation was a critical variable in the accuracy of size estimations, whether from memory or with vision, and that distance had no impact at all on size perception. Furthermore, when distance information was good, size had no effect on distance estimation; in contrast, at far distances, the distances to token variable or unknown objects were estimated with less accuracy. The results suggest that size perception has been misconceptualized, so that the relevant research to understand its properties has not been undertaken. The size-distance invariance hypothesis was shown to be inadequate for both areas of research.     

Perceptual independence in the perception of speech

The purpose of the experiments and analyses was to discover whether the “independence” model, which successfully accounts for the perception of synthetic multi-dimensional stimuli, would also describe the perception of speech in noise. Two sets of four words were chosen which could be considered phonetically to be describable in terms of two dimensions. The S/R matrix was analysed as if the stimuli were bi-dimensional elementary stimuli. Satisfactory fits were obtained by the independence model. Two analyses were conducted upon data from Miller and Nicely (1955) and Conrad (1964) to discover whether the perception of phonemes was also predictable on the independence model. In general this was found to be the case.     

Figural aftereffects in the perception of faces

We examined figural aftereffects in images of human faces, for which changes in configuration are highly discriminable. Observers either matched or rated faces before or after viewing distorted images of faces. Prior adaptation strongly biases face perception by causing the original face to appear distorted in a direction opposite to the adapting distortion. Aftereffects transferred across different faces and were similar for upright or inverted faces, but were weaker when the adapting and test faces had different orientations (e.g., adapt inverted and test upright). Thus the aftereffects depend on which images are distorted, and not simply on the type of distortion introduced. We further show that the aftereffects are asymmetric, for adapting to the original face has little effect on the perception of a distorted face. This asymmetry suggests that adaptation may play an important normalizing role in face perception. Our results suggest that in normal viewing, figural aftereffects may strongly influence form perception and could provide a novel method for probing properties of human face perception.     

Evaluating the independence of sex and expression in judgments of faces

Face recognition models suggest independent processing for functionally different types of information, such as identity, expression, sex, and facial speech. Interference between sex and expression information was tested using both a rating study and Garner's selective attention paradigm using speeded sex and expression decisions. When participants were asked to assess the masculinity of male and female angry and surprised faces, they found surprised faces to be more feminine than angry ones (Experiment 1). However, in a speeded-classification situation in the laboratory in which the sex decision was either "easy" relative to the expression decision (Experiment 2) or of more equivalent difficulty (Experiment 3), it was possible for participants to attend selectively to either dimension without interference from the other. Qualified support is offered for independent processing routes.     

Revisiting the perception of upside-down faces

In two experiments, the effect of orientation on face perception was assessed. Using a scale from 1 ( normal ) to 7 ( bizarre ), participants rated normal, unaltered faces and faces in which changes had been made to spatial-relational properties (eyes and mouth inverted or relative position of the eyes and mouth altered) or to component properties (eyes whitened and teeth blackened). For unaltered and component-distortion faces, bizarreness ratings increased linearly as orientation increased from 0° to 180°. For spatial-distortion faces, a discontinuity in the function relating orientation and bizarreness was in evidence between 90° and 120°. The results provide support for the view that there is a qualitative difference in the processing of upright and inverted faces due to the disproportionate effect of inversion on the encoding of spatial-relational information.     

Categorical perception occurs in newly learned faces, other-race faces, and inverted faces

On the basis of findings that categorical perception (CP) is possible in complex visual stimuli such as faces, the present study tested for CP on continua between unfamiliar face pairs. Results indicate that CP can be observed for unfamiliar faces, in both familiar (same-race) and unfamiliar (other-race) groups. In addition, significant CP effects were observed in inverted faces. Finally, half-continua were tested where midpoint stimuli became endpoints. This was done to ensure that stimulus artifacts did not account for the observed CP effects. Consistent with the perceptual rescaling associated with CP, half-continua showed a rescaled CP effect. We argue that these CP effects are based on the rapid acquisition of perceptual equivalence classes.     

Psychophysical test for the independence of perception and action

Research has suggested that perception and action are independent (see M. A. Goodale & A. Haffenden, 1998). The authors used the Ebbinghaus illusion to test this hypothesis in 2 experiments. Verbal reports of perceived size were compared with maximum grip aperture during grasping (Experiment 1) and manual reports of perceived size (Experiment 2). A multidimensional signal detection analysis was used to distinguish among the possible interactions between the two processes in each experiment (H. Kadlec & J. T. Townsend, 1992a, 1992b). In Experiment 1, the percepts were independent, and there were no interactions between processes for verbal and visuomotor responses. In Experiment 2, the percepts associated with verbal and manual reports were independent, but the processes interacted at the levels of the stimulus information and the decision rules used to transform each percept into a response.     

Bilateral tachistoscopic perception,handedness, and laterality: II. Nonverbal stimuli

Thirty-two Subjects were assigned to four groups on the basis of handedness (left or right) and familial sinistrality (absent or present). Their laterality patterns were investigated with a cued order-of-report paradigm. On each trial, Subjects saw a tachistoscopic presentation of two outline drawings of common objects, one drawing on the left of a central fixation point, one on the right. A centered arrowhead appeared with the pictures; the arrowhead pointed either left or right, and its direction indicated the order of report. The results for each group were discussed in terms of asymmetry for rate of processing and rate of decay, and in comparison with our earlier study of word recognition.     

Categorical perception of newly learned faces

Five experiments investigated identification and discrimination of faces. Stimuli were blends of two faces generated with a morphing algorithm. Two same-gender and two different-gender pairs of faces were tested. Experiment 1 (identification) estimated the point of indifference along the morphing sequence, and the associated differential threshold. Experiment 2 (discrimination, ABX) demonstrated that novel faces are perceived categorically. Identity was a more important factor than gender in generating the perceptual categories. Experiment 3 and 4 (identification) demonstrated that categories are generated progressively in the course of the experiment and depend on the range of morphs tested in any one condition. Confidence ratings (Experiment 5) showed that the multidimensional space where faces are represented can be collapsed onto a single dimension. Response probabilities and response times for Experiments 1–4 were predicted simultaneously by a counting model postulating that quanta of discriminal information are sampled independently from the stimuli.     

Mood and sex of participant in perception of happy faces

The influences of mood-state and sex of subject were examined for ratings of the emotional intensity of videotaped facial expressions of happiness. 102 subjects who were classified by sex and their scores on the Beck Depression Inventory provided ratings of the faces. A significant sex by mood-state interaction indicated that ratings of intensity by men and women were influenced differently by mood-state, and these findings are interpreted within the framework of the Affect Infusion Model. The results support our hypothesis that men and women tend to rely preferentially on low and high affect infusion strategies, respectively. The findings further suggest that the cognitive effect of affect infusion on the magnitude of perceived intensity of facial affect could be influenced by mood-state via differences in cognitive effort subjects employ when in a dysphoric or nondysphoric mood.     

Differences in attentional involvement underlying the perception of distinctive and typical faces

Differences in human faces can be evaluated along a continuum that ranges from 'distinctive' to 'typical.' We examined processing differences between distinctive and typical faces by two attentional tasks that induce attentional blink (AB). Given that AB is believed to reflect temporal or capacity limits of attention, stimuli that survive AB are believed to be associated with greater processing efficiency. In a change-detection task, participants were required to detect changes in the two pairs of faces that were presented in rapid succession. Changes involving the distinctive face of a pair were more likely to be detected than those involving a typical face. In a face-identification task, distinctive faces embedded in a rapid serial visual presentation (RSVP) stream were identified with a greater accuracy than typical faces. Together, our results suggest that distinctive faces are associated with greater processing efficiency and may be explained in terms of perceptual salience, a stimulus dimension known to attract attention.