The personal-group discrepancy: Is there a common information basis for personal and group judgment?

In contrast to motivational accounts of the personal-group discrepancy, results from this article suggest that the discrepancy is explained by aggregating different sets of comparison outcomes for either personal or group ratings. Results from a longitudinal study with East German (the minority group) and West German (the majority group) samples confirm the personal-group discrepancy and support our approach. First, social comparisons influenced evaluations of economic situation at both group and personal levels. Second, ratings of group versus personal economic situation were based on different sets of comparisons. Third, the mean structure of both sets of comparison outcomes mirrored the personal-group discrepancy. Fourth, an interaction between personal-group discrepancy and group status supported the authors' suggestions-concerning the direction of the discrepancy.     

Comparison of the Trail Making and Color Trails Tests in a Chinese context: a preliminary report

The Color Trails Test developed as a culturally fair analogue of the Trail Making Test, was used to examine the relationship between the two tests with 35 undergraduate Chinese in Hong Kong recruited as the subjects. The scores on these two tests of the 12 men and 23 women were significantly correlated .71. The equivalence of the Trail Making and Color Trails Tests when applied to Chinese in Hong Kong was discussed.     

Usefulness of assessment techniques in assessing classification for emotional disturbance and generating classroom recommendations

A national survey of specialist school psychologists examined the perceived usefulness of assessment techniques in making decisions regarding eligibility for the educational classification of emotional disturbance and in generating classroom recommendations. Analysis showed measures rated as most useful were interviews with the parent, teacher, and student, observations of the student, and norm-referenced rating scales. Projective techniques were least useful. These findings are important in the context of "best practices" for the multidimensional assessment of emotional disturbance which promotes a more direct link between assessment and intervention.     

Use of photic feedback as an adjunct treatment in a case of Miller Fisher syndrome

Photic Feedback treatment of a patient diagnosed with Miller Fisher syndrome has resulted in the rapid and permanent remission of symptoms. During Photic Feedback treatment, the CD20 appeared to be slightly increased. This may have been associated with changes in humoral immunity. The present clinical observation of a single patient suggests that Photic Feedback treatment should be investigated as a possible adjunct therapy for patients who suffer from polyneuropathies, such as Miller Fisher syndrome, within a carefully controlled clinical trial.     

Emotion space as a predictor of binocular rivalry

In our 1999 report, we examined robustness of a two-dimensional structure of facial expressions of emotion under the condition of some perceptual ambiguity, using a stereo-scope. The current study aimed to replicate and extend the previous work by adding facial photographs of different persons and by measuring participants' perception of stereoscopically presented faces. Multidimensional scaling provided a two-dimensional configuration of facial expressions comparable with the previous studies. Although binocular rivalry was a less frequent phenomenon, it was suggested that the distances between facial expressions in the derived space were a contributing factor in eliciting binocular rivalry.     

A signal detection model predicts the effects of set size on visual search accuracy for feature, conjunction, triple conjunction, and disjunction displays

Recently, quantitative models based on signal detection theory have been successfully applied to the prediction of human accuracy in visual search for a target that differs from distractors along a single attribute (feature search). The present paper extends these models for visual search accuracy to multidimensional search displays in which the target differs from the distractors along more than one feature dimension (conjunction, disjunction, and triple conjunction displays). The model assumes that each element in the display elicits a noisy representation for each of the relevant feature dimensions. The observer combines the representations across feature dimensions to obtain a single decision variable, and the stimulus with the maximum value determines the response. The model accurately predicts human experimental data on visual search accuracy in conjunctions and disjunctions of contrast and orientation. The model accounts for performance degradation without resorting to a limited-capacity spatially localized and temporally serial mechanism by which to bind information across feature dimensions.     

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.     

Extraretinal and retinal amplitude and phase errors during Filehne illusion and path perception

Pursuit eye movements give rise to retinal motion. To judge stimulus motion relative to the head, the visual system must correct for the eye movement by using an extraretinal, eye-velocity signal. Such correction is important in a variety of motion estimation tasks including judgments of object motion relative to the head and judgments of self-motion direction from optic flow. The Filehne illusion (where a stationary object appears to move opposite to the pursuit) results from a mismatch between retinal and extraretinal speed estimates. A mismatch in timing could also exist. Speed and timing errors were investigated using sinusoidal pursuit eye movements. We describe a new illusion--the slalom illusion--in which the perceived direction of self-motion oscillates left and right when the eyes move sinusoidally. A linear model is presented that determines the gain ratio and phase difference of extraretinal and retinal signals accompanying the Filehne and slalom illusions. The speed mismatch and timing differences were measured in the Filehne and self-motion situations using a motion-nulling procedure. Timing errors were very small for the Filehne and slalom illusions. However, the ratios of extraretinal to retinal gain were consistently less than 1, so both illusions are the consequence of a mismatch between estimates of retinal and extraretinal speed. The relevance of the results for recovering the direction of self-motion during pursuit eye movements is discussed.     

Odorant quality perception: a metric individual differences approach

Perceptual spaces, in which similar stimuli are located close to each other and dissimilar stimuli are located far apart, have aided in the understanding of the physiological and psychological bases for sensory quality coding. Differences in perception between individuals should be reflected by differences in the spatial relationships between stimuli. If the dimensionality of the perceptual space is small (e.g., color space), individual differences that reflect specific pathologies are readily apparent from visual inspection. On the other hand, if the dimensionality of the perceptual space is large (as is proposed for odor space), visual inspection alone may not reveal individual differences in quality perception. The present work presents an information-theory-based method for quantifying individual differences in quality perception from perceptual confusion matrices. The ability of this method to quantify individual differences in quality perception is shown in a hypothetical example of specific anosmia. Finally, the method is applied to the examination of intrasubject consistency of odorant quality perception.