Surface tilt (the direction of slant): A neglected psychophysical variable

Surface slant (the angle between the line of sight and the surface normal) is an important psychophysical variable. However, slant angle captures only one of the two degrees of freedom of surface orientation, the other being thedirection of slant. Slant direction, measured in the image plane, coincides with the direction of the gradient of distance from viewer to surface and, equivalently, with the direction the surface normal would point if projected onto the image plane. Since slant direction may be quantified by the tilt of the projected normal (which ranges over 360 deg in the frontal plane), it is referred to here assurface tilt. (Note that slant angle is measured perpendicular to the image plane, whereas tilt angle is measured in the image plane.) Compared with slant angle’s popularity as a psychophysical variable, the attention paid to surface tilt seems undeservedly scant. Experiments that demonstrate a technique for measuring apparent surface tilt are reported. The experimental stimuli were oblique crosses and parallelograms, which suggest oriented planes in 3-D. The apparent tilt of the plane might be probed by orienting a needle in 3-D so as to appear normal, projecting the normal onto the image plane, and measuring its direction (e.g., relative to the horizontal). It is shown to be preferable, however, to merely rotate a line segment in 2-D, superimposed on the display, until it appears normal to the perceived surface. The apparent surface tilt recorded in these experiments corresponded closely to that predicted by assuming the 3-D configurations consist of equal-length lines and perpendicular intersections.     

On the semantic content of subcategorization frames

This paper investigates relations between the meanings of verbs and the syntactic structures in which they appear. This investigation is motivated by the enigmas as to how children discover verb meanings. Well-known problems with unconstrained induction of word meanings from observation of world circumstances suggest that additional constraints or sources of information are required. If there exist strong and reliable parallels between the structural and semantic properties of verbs, then an additional source of information about verb meanings is reliably present in each verb's linguistic context. Five experiments are presented which investigate the following hypothesis regarding the scope of these relations: The closer any two verbs in their semantic structure, the greater the overlap should be in their licensed syntactic structures. To investigate this hypothesis, data of two kinds were collected from different groups of subjects: (a) One group of subjects was asked to judge the semantic relatedness of verbs by selecting the semantic outlier in triads presented to them. (b) A second group of subjects was asked to judge the grammaticality of these same verbs in a large range of syntactic environments. These two types of data were then compared to assess the degree of correspondence in the two partitionings (syntactic and semantic) of the verb set. The findings, overall, support the view that the syntax of verbs is a quite regular, although complex, projection from their semantics. In conclusion, we discuss the kinds of features that are formally marked in syntactic structure and relate these to the problem of verb-vocabulary acquisition in young children.     

Effect of situational factors on the self-attributions of females and males

The simultaneous effects of the sex-role appropriateness of the task and the presence or absence of competition upon the attributions made by males and females were studied with 192 college students. Contrary to predictions, males rated themselves as luckier than females in the competitive conditions. However, as predicted, females made fewer self-serving attributions for the male than the female task.     

An automated eye movement laboratory for on-line electrooculography

This paper describes an automated eye movement laboratory that uses electrooculography (EOG) to study people’s eye movements while they read. An on-line minicomputer processes bioelectric potentials that correspond to saccadic eye movements. Horizontal saccades larger than 1.5 deg of visual angle are detected and analyzed in real-time as they occur. The laboratory is designed for prolonged yet unobtrusive observation of human eye movements during sustained reading periods of minutes or hours. All important functions regarding data collection and data reduction are performed automatically, according to simple procedures that can be applied uniformly and without bias to nearly all subjects that we study. Results from three experiments are cited in order to quantify the performance of the laboratory with respect to four criteria: saccade detection accuracy, measurement accuracy, sensitivity, and the uniformity of these measures over different subjects.     

MULTIVARIATE ASSESSMENT OF CONFLICT IN DISTRESSED AND NONDISTRESSED MOTHER-ADOLESCENT DYADS

A battery of measures was used to assess conflict between mothers and young adolescents (females and males, 11 to 15 years of age). Two groups of families, one composed of a distressed clinical sample (N = 38), the other a nondistressed normative sample (N = 40), participated. The assessment battery included retrospective judgments, frequency estimates, self-monitored home recording, and tape-recorded discussion of a home problem. Content of assessment measures tapped aspects of parental control, decisionmaking, self-reported interaction behavior, arguments, interaction behavior rated by independent “blind” observers, frequency and anger-intensity of specific problematic issues, and perceptions of positive and negative behaviors of the other family member. Based on univariate analyses, 21 of the 26 defined variables discriminated significantly in the predicted direction. Maternal and adolescent reports of behavior and independent ratings of tape-recorded interaction emerged as strong and consistent discriminators. Stepwise multivariate discriminant analysis provided successful classification of 100% of the families based on the inclusion of nine variables. In a cross-validation sample, 84% of the families were correctly classified. Implications for systematic outcome research as well as clinical application are discussed.     

Transection of direct anterior thalamic afferents from the hippocampus: effects on activity and active avoidance in rats

This investigation demonstrates the importance of the direct hippocampo-anterior thalamic component of the postcommissural fornix in the control of general locomotion and active avoidance. Transection of anterior thalamic afferents from the hippocampal formation (subicular cortex), at the point where they exit from the fornix posterior to the septum, is sufficient to enhance bidirectional active avoidance acquisition and increase general activity. This transection may also interrupt fibers to or from other thalamic nuclei and the anterior septum. However, destruction of connections of the anterior septum with the hippocampus, habenula, and thalamus by transection in the coronal plane anterior to the descending fornix columns, without damage to the subiculothalamic fibers, increases general activity levels without damage to the subiculothalamic fibers, increases general activity levels without affecting active avoidance behavior. The activity increase in this case resembles that seen after septal lesions rather than that seen after hippocampal lesions. Thus, destruction of a single fornix component contributing afferents to the anterior thalamic nuclei reproduces at least part of the hippocampal syndrome. This suggests that these fibers contribute significantly to the control of these behaviors and may mediate active avoidance changes resulting from hippocampal and fornix damage.     

OVERJUSTIFICATION EFFECTS IN TOKEN ECONOMIES

This study tested the relevance to clinical token economies of the overjustification hypothesis that tangible reward interferes with intrinsic interest in target behaviors and causes such behaviors to be less probable following a period of reinforcement than preceding such a period. The study was carried out in an ongoing token economy for chronic psychiatric patients. Alternated over an 8-week period were weeks of token and no-token reward for one of the program's target behaviors, toothbrushing. Two different amounts of token reward were employed in order to examine whether reward magnitude might influence the presence or extent of overjustification effects. Little evidence was found for the presence of overjustification effects in token economies. However, maintenance of toothbrushing was greater in no-token weeks following weeks of low amounts of token reward than in no-token weeks following weeks of higher amounts of reward. The importance of such complex functional relationships is discussed.     

Comparison of observational recordings in vivo, via mirror, and via television

Simultaneous observational recordings were made in vivo, via an observation mirror, and via closed circuit television. Three of nine observers had extensive experience recording behavior in vivo; three had extensive experience recording behavior via mirror; and three had extensive experience recording via television. Observers recorded nine categories of disruptive behavior for children in a special class setting. Frequencies of behavior recorded in vivo, via mirror, and via television differed significantly for only one category, vocalization. There were no significant main effects or interactions involving the observers' previous experience. Occurrence reliability coefficients computed within and between media demonstrated the similarity of observer agreement in all three media. Data collection procedures using an observational mirror or closed circuit television appear to be reasonable alternatives to in vivo observation in circumstances similar to those in the present study.     

Helping is not enough: Recipient's reactions to aid as a function of positive and negative information about the self

The present research investigated the effects of experimentally induced positive and negative feedback about the self on the recipient's subsequent reactions to aid. In line with a consistency prediction, subjects given positive feedback who later received aid had lower mood ratings and less favorable self-evaluations than those who were given positive feedback but no subsequent help. Conversely, subjects given negative feedback who later received aid had higher mood ratings and more positive self-evaluations than those who were given negative feedback but no subsequent help. Subjects' evaluations of another individual were characterized by aid main effects, which indicate that an other who helped was evaluated more favorably than an other who did not help. The conceptual and applied implications of these results are discussed.