A method for the analysis of complex avian song repertoires

A new method for the analysis of complex avian song repertoires is introduced. The method consists of sending a tape-recorded bird-song signal through five narrow band-pass filters and then to a five-channel high-speed pen recorder. A coding method that allows a researcher to convert the output from the pen recorder to numbers for later analysis by computer is described.     

Dynamic visual noise and the stereophenomenon: Interocular time delays,depth, and coherent velocities

Attention, Perception, & Psychophysics - This study concerns the stereophenomenon obtained with binocular viewing of dynamic visual noise with a neutral density filter over one eye. Such a...     

Carryover effects of a summer therapeutic daycamp program on children''s classroom behavior: A one-year follow-up

The study investigated the impact of a Summer Therapeutic Daycamp on the subsequent classroom behavior of behaviorally disordered children. Pre-post assessment of the maladaptive behavior of children participating in the program and of a control group one year subsequent to the program demonstrated the differential impact of the program, consistent with the notion of intensive, time-limited intervention as an effective alternative to extended treatment.     

Assessment of the relative importance of S+ and S− in rats using differential training on intercurrent discriminations

The present studies assessed the degree of stimulus control exerted by S+ and S? without confoundings of stimulus novelty and stimulus ambiguity. In Experiment 1, rats were trained on two intercurrent simultaneous discrimination problems with nine times more training given on one than the other. Then the animals were given transfer tests with re-paired stimuli. The results showed that S? exerts greater stimulus control than S+ in a two-choice simultaneous discrimination. Experiment 2 provided a test of the possibility that the relative degree of control by S? varies with different amounts of training. Three groups were trained on two intercurrent simultaneous discrimination problems; each group was given 7, 11, or 15 times more training on one problem than the other. Then transfer tests were given with re-paired stimuli. Again the results showed that S? exerts greater stimulus control than S+ in a two-choice simultaneous discrimination.     

Regional cerebral blood flow response to recognition memory versus semantic classification tasks

Two randomly assigned groups, N = 7 each, of neurologically normal patients were composed. One group, RM, had regional cerebral blood flow measurements during a recognition memory probe test; the other group, SC, had rCBF measurements during a semantic classification task, using the same stimulus and response features as the RM task. Thus, the groups differed only in the cognitive instruction they were executing. The RM group showed a significantly lower change from resting baseline to activation, in mean left hemisphere initial slope index, than did the SC group. The RM group, but not the SC group, showed a significant inverse correlation between occipital flow and accuracy of memory performance as indicated by d′. Correlations between age and hemispheric initial slope index, and between homologous left and right hemisphere sites, were also described. The results are considered to support an anatomical basis for the distinction between episodic and semantic memory and to suggest that occipital flow may diminish with accurate memory performance because of an upstream demand of blood in the medial temporal lobes.     

The effect of set size on hemifield asymmetries in letter recognition

Single letters were presented tachistoscopically in the left or right hemifield to right-handed observers. Superior recognition of letters on the right was found for letters chosen from subsets containing four items, but no differences were found when any letter, or any symmetrical letter, could appear. In a second experiment, the right hemifield advantage was found under conditions requiring the subject to determine the subset only when the subset chosen was appropriate. Results were discussed in terms of the adequacy of language-based explanations of hemifield asymmetries in letter recognition.     

Formal assessment of problem-solving and planning processes in preschool children

While much is known about adult problem-solving, the materials, analyses, and theoretical issues from the adult literature rarely make contact with the tasks typically used to investigate children's thinking. This paper examines the behavior of 4-, 5-, and 6-year-old children attempting to solve a novel variant of the Tower of Hanoi task. Problems varied in difficulty (one to seven moves for the minimum path solution) and in goal type: tower (all objects on one peg) or flat (all pegs occupied). For each problem, children gave verbal statements of their complete solution plan. The Plan Analysis examined performance as a function of goal type and age. Better performance was observed for tower ending problems, and among older children. The Error Analysis revealed that specific error propensities were related to both age and goal type. The Strategic Analysis compared the first move profiles of 6-year-olds to those of several plausible move selection models, and a high degree of correspondence was obtained between specific models and individual children. Young children appear to have rudimentary forms of many of the problem-solving processes previously identified in adults, but they may differ in encoding and representational processes.