A primate restraint and handling system for auditory research

A set of devices is described that enables daily handling and restraint of large primates. The animals live in cages and wear a special collar that fits into a modified primate restraining chair. A chain and pole arrangement simplifies the daily chairing procedure. A method of head restraint and earphone mounting is also described.     

Redistributing control between the elements of a compound stimulus

Twenty-eight pigeons were given discrimination training. Four groups were run in which for 0, 2, 4 and 9 sessions of training colour was an irrelevant cue and tone was relevant. Generalization tests were given in extinction; the training colour (C₁) and another colour (C₂) were presented with tone (T) and noise (N). Responding to these four stimulus combinations, TC₁, TC₂, NC₁ and NC₂, allowed the assessment of control by colour and tone. A reduction of control by colour and an increase in control by tone were found to be positively related to the amount of training with colour irrelevant. Tests showed a strong inverse relationship between control by colour and tone.     

Consonant recognition with two levels of decision complexity

The perceptual tuning hypothesis can be expressed as a prediction that discrimination of a particular stimulus dimension will be enhanced if it is the only dimension requiring discrimination and not one of a set of dimensions in a multidimensional discrimination task. In previous tests of the tuning hypothesis, using speech material, the size of a message set has been manipulated as an indirect means of controlling the number of dimensions an observer is required to discriminate. In the present experiments the particular items appearing in a message set have been selected in order to control precisely the number of dimensions relevant to the discrimination task, and performance is estimated in terms of the discrimination of each relevant dimension. No evidence is found for a perceptual tuning effect even though it is argued that the conditions of the present experiment represent those most favourable for its elicitation.     

Characteristics of Schizogenic Families During a Joint Story-Telling Task

For a joint family story-telling task, families with a schizophrenic offspring were compared to normal families on the completeness and clarity of the final composite stories and on their interactional behavior. The composite stories from schizogenic families were more “vague and confused”, fragmented, and less complete as to the five components required to satisfy the task instructions. Schizogenic families displayed more conflict, failure, and confusion during the interactional task than control families, and, fathers and mothers of schizophrenic offspring displayed more “anxiety and tension”, “depressive mood”, “evasiveness” and “lack of interest” than fathers and mothers of normal families. Mothers of schizophrenic offspring were also described as more “hostile” than control mothers. Comparing schizogenic families from which the patient was absent during the task with schizogenic families with the patient present, and with control families, indicated that the central findings were not attributable to the immediate presence and participation of the schizophrenic member.     

The relative effects on math performance of single- versus multiple-ratio schedules: a case study

This series of four experiments sought to assess the comparative effects of multiple- versus single-ratio schedules on a pupil's responding to mathematics materials. Experiment I, which alternated between single- and multiple-ratio contingencies, revealed that during the latter phase the subject responded at a higher rate. Similar findings were revealed by Exp. II. The third experiment, which manipulated frequency of reinforcement rather than multiple ratios, revealed that the alteration had a minimal effect on the subject's response rate. A final experiment, conducted to assess further the effects of multiple ratios, provided data similar to those of Exp. I and II.