Reference frames in mental rotation

Four experiments are reported that investigate whether images or reference frames are transformed during a mental rotation task. In all experiments a display of four identical letters (P1) was presented at either +90 degrees or -90 degrees from upright, and subjects had to decide whether the letters were normal or mirror-image reflections. A single letter (P2) was then presented 100 ms later in a variable orientation with the same task instructions. Reaction times to P2 were assessed to determine whether an image of P2 was rotated to upright or whether an internal reference frame was rotated into congruence with P2 from the orientation of P1. The results as a whole suggest that transformations of P2 can be initiated either relative to upright or relative to the orientation of P1. They further indicate that the probability of using each reference orientation can be changed by procedural variations. The findings are most parsimoniously interpreted as suggesting that mental rotation involves the transformation of reference frames rather than the transformation of template-like representations.     

A comparison of depressed and nondepressed disturbed children on measures of attributional style,hopelessness, life stress,and temperament

Upon admission to a hospital treatment program, clinically depressed and nondepressed children (aged 9–17 years) were assessed on measures of attributional style, hopelessness, depression, life stress, and child temperament. The depressed group tended to attribute positive events to specific and unstable factors when compared with the nondepressed sample. Group differences also were found on child temperament measures. However, no differences were reported between the diagnostic groups on self-reported depression, hopelessness, or life stress. The findings suggested that there may not be a unique constellation of cognitive characteristics in depressed children when compared with a nondepressed clinical sample. For both depressed and nondepressed groups, treatment did appear to affect self-reported depression and overall ratings of depressogenic attributional style.     

How is a trumpet known? The "basic object level" concept and perception of musical instruments

What are the object properties that serve as a basis for the musical instrument classification system, and how do general and specific experience affect knowledge of these properties? In the first study, the multimodal quality of properties underlying children's and adults' perception was investigated. Subjects listened to solos and identified instruments producing the sounds. Even children who did not have experience with all the instruments correctly identified the family of instruments they were listening to. The hypothesis of the second study, that musical instrument families function as a "basic level" in the instrument taxonomy, was confirmed. Variation in the basic level with varying expertise was documented in the third study with musicians. In the fourth study, children and adults identified the source of sounds from unfamiliar objects, Chinese musical instruments. It is suggested that the concept of affordances may be relevant for understanding the importance for behavior of different levels of abstraction of category systems.     

Classwide Peer Tutoring: Effects on the Spelling Performance and Social Interactions of Students with Mild Disabilities and Their Typical Peers in an Integrated Instructional Setting

The effectiveness of Classwide Peer Tutoring (CWPT) to enhance the spelling performance and social interactions of three typical students and three students with mild disabilities was investigated. The classroom ecology was measured using the New Code for Instructional Structure and Student Academic Response (NCISSAR). Social interactions were assessed using the Multiple Option Observation System for Experimental Studies (M.O.O.S.E.S.). Spelling performance was measured by weekly pre-posttests. Using an ABAB single-subject design, results indicated that CWPT resulted in: (a) gains in the spelling accuracy of all students (up to 49%), (b) increases of students' duration of positive social interactions (up to 86%), and (c) high satisfaction ratings for both the students and the teacher. Comparisons between typical students and students with mild disabilities during CWPT suggested no differences in their duration of social interactions. Furthermore, the mean spelling accuracy of the students with mild disabilities was comparable to the spelling accuracy of the typical students (91% vs. 96%, respectively). Implications of the findings for the inclusion of students with mild disabilities in general education settings are discussed.     

An experimental analysis of electricity conservation procedures

Daily electricity consumption of four families was recorded for 106 days. A reversal design, consisting of various experimental conditions interspersed between repeated baseline conditions, was used. During experimental conditions, daily prompts (written conservation slogans attached to front doors) and/or daily feedback (daily kilowatts consumed and daily cost information) were in effect. Maximum consumption occurred during the initial baseline; minimum consumption occurred during different experimental conditions for different families. The mean decrease from the maximum to the minimum for all families was 35%. Reversals in consumption were demonstrated in three families, although successive baselines tended to decrease. No clear differences in effectiveness between prompting and feedback conditions were apparent. The procedures used resulted in considerable dollar savings for the families.     

Factors to be considered in placing handicapped children in regular classes

In light of recent legislation, school psychologists, administrators, and teachers are required to decide if handicapped pupils' educational needs can be met in regular classrooms. This paper examines information that may be used to derive this placement decision and proposes decision-making guidelines to be considered.     

The ontogeny of defensive reactions in the rat: Influence of the monoamine transmission systems

The effects of neonatal treatment of rats with the neurotoxins 5,7-dihydroxytryptamine and 6-hydroxydopamine on the ontogeny of the ultra sound vocalization and the immobility response were studied. The 5,7-dihydroxytryptamine treated rats showed reduced strength of both reactions indicating involvement of the serotonin system in their ontogeny. This hypothesis was supported by experiments with depletion of serotonin by para-chlorophenylalanine followed by replenishment with 5-hydroxytryptophan. The 6-hydroxydopamine treated rats showed normal defensive reactions, but displayed hyperactivity from their second week of age. The role of the dopamine system in the defensive reactions was studied by variations of the dopamine activity level by traditional tools: depletion by α-methyl-tyrosin followed by replenishment by l -DOPA; stimulation or inhibition of the dopamine receptors by apomorphine or haloperidol. The results suggested an inhibitory function of the dopamine system in both defensive reactions, antagonistic to that of the serotonin system.