Simultaneous linear prediction

Given a set of items (predictors) suppose one wishes to predict another set of items (predictands) in asimultaneous way. Such a situation may occur when the predictands are different measurable aspects of the same phenomenon. Alternatively one might wish to predict the success of an event (say a successfully performed task) which has many correlated or uncorrelated failure modes (say a set of possible mental or physical disabilities each of them by itself precluding the achievement of the said task.) In such a case a unidimensional prediction is of value only if prediction is simultaneous for all possible failure modes. A linear summarization of the predictors is suggested, which is unique and has maximum predictability value for all predictands simultaneously. Other summarizations or scores are found that give maximum explanation of residual measures on the predictands and that are uncorrelated. The set of those simultaneous linear predictions is compared to the set of the individual multiple regression predictions as used, for instance, in the same context by Horst [4] for each predictand given the original predictors. We suggest that this technique can be applied in particular to the summarization of a subset of items when the whole set of items constitutes the set of predictands.This work was initiated at Stanford University under contract 2-1-065 with U. S. Office of Education and was partly revised at the Université de Montréal.I wish to express my gratitude to Professor Herbert Solomon, Stanford University, for his unfailing assistance at all stages of my work.     

Flicker thresholds as determined by a modified conditioned suppression procedure,

Critical flicker fusion frequencies were determined as a function of stimulus intensity for three White Carneaux pigeons using a modified conditioned suppression paradigm as a threshold procedure. Critical frequencies ranged from 6 cps for the lowest intensity of 0.0014 ml to 77 cps for the maximum intensity of 41.86 ml.     

Consolidation of Memory for Odor–Reward Association: β-Adrenergic Receptor Involvement in the Late Phase

Experimentally naive rats can learn rapidly to discriminate among three odors to obtain food reinforcement. After three massed trials, they show almost errorless performance. This task has proved to be useful in studying time-dependent postacquisition intracellular processes necessary for long-term memory. The present experiments evaluated the temporal dynamics of the role of β-noradrenergic receptors in long-term consolidation. Rats were implanted with intracerebroventricular cannulae and trained in a single session to find reinforcement in a hole in a sponge impregnated with a particular odor. Injections of the β-receptor antagonist timolol were made at 5 min, 1, 2, or 5 hr after training. Memory and relearning ability were evaluated 48 hr later. Rats treated with timolol 2 hr after training showed a memory deficit at the retention test, but were able to relearn the task normally. Injections at the earlier or later time points were ineffective. The results reinforce previous observations with systemic injections that β-noradrenergic receptors are involved in the late phase of memory consolidation and suggest a critical time window during which they are necessary. The time window is compatible with the current view that long-term memory depends on late involvement of the cAMP cascade leading to new protein synthesis necessary for synaptic reorganization.     

The History of Family Therapy in South Africa

The history of family therapy in South Africa is presented from 1960 up to the present. The early days leading to the establishment of the South African Association of Marital and Family Therapy, national conferences, publications, national and international links are discussed.     

The effects of alphabetic-reading competence on language representation in bilingual Chinese subjects

Summary The metaphonological abilities of two groups of bilingual Chinese adults residing in the Netherlands were examined. All subjects were able to read Chinese logograms, but those in the alphabetic group had, unlike those in the non-alphabetic group, also acquired some competence in reading Dutch. In Experiment 1, strong, significant differences between the two groups were obtained in the task of deleting the initial consonant of a Dutch spoken pseudo-word and also in a task consisting of segmenting a sentence into progressively smaller fragments, but there was no difference in a rhyme-nonrhyme classification task with pairs of Dutch words. In the latter task, the subjects in the two groups performed at a near-ceiling level. In Experiment 2, a significant difference was obtained again for the consonant-deletion task and no difference with an initial syllabic-vowel-deletion task, but the non-alphabetic subjects performed at a significantly lower level than the alphabetic subjects in the rhyme-judgement task. Taken together, these results are consistent with the earlier evidence that learning a non-alphabetic orthography does not promote awareness of the segmental structure of utterances. On the other hand, they confirm, for a population of Chinese readers, the conclusion drawn earlier from work with illiterate subjects that explicit instruction is more critical for the development of segmental representations of language than of representations of higher levels such as those of rhymes and syllables.     

Phenomenology of film music

This is a revised version of a paper written for Professor David Raksin's class in film music, Fall 1976, at the University of Southern California.     

ACTIVITÉ MÉTACOGNITIVE DE L'ENFANT ET DIFFICULTÉ DE LA TÂCHE COGNITIVE

The influence of the type of difficulty of a cognitive task on metacognitive activity (metacognitive experiences and metacognitive strategies) was studied in six- and eight-year-old children. Children had to make decisions about the correspondence of statements and drawings presented in pairs one after the other, starting either with a statement, or with a picture. They encounter two kinds of difficulties: (1) one due to the information conveyed by drawing (non-correspondence with the statement); (2) another due to the order in which the statements and drawings are presented: when the drawing comes first the child must retain it in his memory until a statement can guide him in his decoding of it; this difficulty is unexpected given the expectations the child has due to the cognitive task proposed. The principal findings were as follows: (1) Compared to the six-year-olds, the eight-year-olds demonstrated three times more metacognitive control strategies for expressing information, more cognitive skills (reasoning), and a higher level of performance (understanding and recall). (2) The two types of difficulties do not have the same effects: (a) the difficulty due to the information conveyed by the drawing leads to an increase in the latency time; the performance (understanding) is not as good; (b) in the case of difficulty due to the statement-drawing order, twice as many verbalizations expressing metacognitive experiences and a decrease in the latency time were observed. The interpretation of the findings underscores the importance for the child of the indicators he has to orient him in mobilizing metacognitive and cognitive activities.     

ETUDE COMPARATIVE DES EVALUATIONS COLLECTIVES ET INDIVIDUELLES DE LA PENSEE FORMELLE

The purpose of the present study is to examine the effects of different individual and group testing procedures on the success rate obtained by subjects on different formal problems. Four testing conditions were compared: a clinical interview; an individual interview without intervention; a group test with a demonstration of the material; and a group paper-and-pencil test. The four conditions are defined according to several variables that were deemed important for the explanation of potential performance outcomes. All subjects were administered the following four Piagetian derived tasks: a projection of shadows task; a permutation task; an equilibrium in the balance task; and an interrupter combinations task. According to the general hypothesis, subject performance should be optimal for the clinical interview and decline gradually as the assumed advantages of this method are systematically removed, i.e., counterquestioning of the examiner, retrials, subject-examiner interactions, familiarization with the material, etc. The results show that there are performance differences between the conditions, but mainly across the individual and group situations. However, mean ranks obtained from each condition indicate that the facilitating variables identified in the first three conditions have a certain influence on subject performance. Implications regarding a choice of a valid mesurement of formal thought are discussed.     

IN-HOME GENERALIZATION OF SOCIAL INTERACTIONS IN FAMILIES OF ADOLESCENTS WITH BEHAVIOR PROBLEMS

The effects of a three-phase family communication program were evaluated. In the skill-teaching phase, family members were taught reciprocal social communication skills in a clinic setting. During the skill-review phase, each family member practiced the skills in their homes with the teacher. During the home-based family conference phase, each family was taught to use a structured format to resolve current family issues using their newly acquired skills. In-home parent-youth interactions were observed during a series of 1-hr sessions that involved directed and nondirected situations. Evaluation included a multiple baseline design across skills during the skill-teaching phase and a multiple baseline design across families for the family conference phase. Although the procedures of the skill-teaching phase resulted in parent-adolescent dyads learning to use the skills in the teaching setting, competent use of the skills in the home was not observed until the family conference phase was implemented. These results suggest the importance of home-based intervention if changes are to be obtained at home.