THE VISUAL SYSTEM'S MEASUREMENT OF INVARIANTS NEED NOT ITSELF BE INVARIANT

Abstract— When two shapes that differ in orientation or size have to be compared or objects have to be recognized from different viewpoints, the response time and error rate art systematically affected by the size of the geometric difference. In this report, we argue that these effects are not necessarily solid evidence for the use of mental transformations and against the use of invariants by the visual system. We report an experiment in which observers were asked to give affine-invariant coordinates of a point located in an affine frame defined by three other points. The angle subtended by the coordinate axes and the ratio of the lengths of their unit vectors systematically affected the measurement errors. This finding demonstrates that the visual system's measurement of invariants need not itself be invariant.     

Spontaneous startle activity in newborn infants

Spontaneous startles have been reported to occur most frequently in quiet sleep, less frequently in active sleep and drowse, and relatively nonexistent in the waking states. These findings may be a result of a focus on infants whose prenatal histories reflect a restricted range of the conditions to which normal newborns are exposed. The present study examined the spontaneous startle behavior of 30 newborn infants characterized by high numbers of obstetric complications and by indicators of prenatal malnutrition, but within the range of normal, healthy newborns. In this sample, startles were not limited to the sleep and drowse states. Because individual differences in a number of neonatal behaviors have been related to autonomic nervous system (ANS) functioning, the different pattern of spontaneous startles observed in this sample may be related to the functional integrity of this system.     

Direct versus indirect response-reinforcer relationships in teaching autistic children

One possibility suggested by the literature for maximizing the efficiency of behavior modification procedures concerns the relationship between target behaviors and their reinforcers. Therefore, in this experiment three severely autistic children were taught a total of six new target behaviors (in a multiple baseline design) employing two different response-reinforcer relationships: (1) those where the target behaviors were a direct part of the response chain required to procure a reinforcer (e.g., opening the lid of a container to obtain a food reward inside the container); and (2) those where the target behavior was an indirect part of the chain leading to the reinforcer (e.g., the therapist handing the child a food reward after the child had opened the lid of an empty container). In all cases, the results showed rapid acquisition only when the target behavior was a direct part of the chain leading to the reinforcer. The results are discussed in terms of several possible conceptualizations concerning efficient reinforcement contingencies, and in terms of their implications for teaching autistic children.This investigation was supported by U.S. Public Health Service Research Grants MH 28210 and MH 28231, and by U.S. Office of Education Research Grant G007802084 from the Bureau for the Education of the Handicapped. Portions of the results described in this article were discussed in a presentation at the 13th Annual AABT Convention in San Francisco, 1979. The authors are particularly grateful to Andrew Egel, Roberta Elman, Janis Costello, and Karen Britten, for their helpful comments, and to Jody Fisher and Gina Richman, for their assitance in the data collection.     

Attention to important versus trivial tasks and salience of fatigue-related symptoms for coronary prone individuals

The present study tested the hypothesis that individuals with the Type A coronary prone behavior pattern focus their attention more on important tasks, and less on trivial tasks than do Type B's. The study used a paradigm in which some subjects worked on math problems (important task) and rated intervening mood items (trivial task), whereas others rated mood items they were to memorize (important task) and worked on intervening math problems (trivial task). All subjects were later tested on recall of mood items. Results indicated that Type A's performed better on math problems and recalled more fatigue-related mood items when the task was important than when it was trivial; for Type B subjects, there was no difference in the number of math problems solved correctly or number of mood items recalled between important and trivial task conditions. Moreover, Type A's reported greater fatigue when mood recall was the important task than when math was the important task, whereas fatigue ratings of Type B's did not differ across these conditions. The findings suggest that Type A's suppress their attention to fatigue-related symptoms only when symptoms are not the objects of focus.     

Recognition memoryfor pictorial events

Subjects viewed sequences of slides depicting everyday events, and in later recognition tests, they correctly rejected distractors that were inconsistent with some invariant of the event but falsely accepted consistent distractors. J. J. Jenkins has accounted for the differential recognition of consistent and inconsistent slides of pictorial sequences in terms of fusion, the abstraction of an event from a series of temporally related items. The conditions under which event fusion was likely to occur were manipulated in three experiments: degree of ordering of the action-sequence slides, semantic vs. nonsemantic orienting tasks during acquisition, and duration of retention interval Recognition performance was generally more accurate under conditions of semantic processing, ordered acquisition sequences (for the semantic task), and shorter retention intervals. However, these variables did not affect differential recognition of consistent vs. inconsistent slides. A further experiment showed that the absence of an effect of disordering acquisition sequences on differential recognition could not be attributed to subjects’ reordering the disordered sequences in a way consistent with the original event. The data did not support the hypothesis that recognition performance was based on fusion of events depicted by temporally ordered slide sequences. It was suggested that memory for featural detail is a relevant factor in performance.     

On the conflict between logic and belief in syllogistic reasoning

Three experiments are reported that investigate the weighting attached to logic and belief in syllogistic reasoning. Substantial belief biases were observed despite controls for possible conversions of the premises. Equally substantial effects of logic were observed despite controls for two possible response biases. A consistent interaction between belief and logic was also recorded; belief bias was more marked on invalid than on valid syllogisms. In all experiments, verbal protocols were recorded and analyzed. These protocols are interpreted in some cases as providing rationalizations for prejudiced decisions and, in other cases, as reflecting a genuine process of premise to conclusion reasoning. In the latter cases, belief bias was minimal but still present. Similarly, even subjects who focus primarily on the conclusion are influenced to an extent by the logic. Thus a conflict between logic and belief is observed throughout, but at several levels of extent.     

The Use of Progressive Relaxation and Hypnosis in Counselling Secondary-School Pupils

Counselling methods involving progressive relaxation and hypnosis are sometimes regarded as being mysterious and alarmingly innovatory, particularly within the context of the secondary-school system. The implications for counselling practice of the use of such methods are considered. Some ways in which they have been used to help young people of secondary-school age are outlined. A number of illustrative case-studies are given, and a relatively unsuccessful case-study is included.