Lars-Göran Nilsson

Role of exteroceptive background context in taste-aversion conditioning and extinction

In two experiments, saccharin (CS) and lithium chloride (US) were paired in a context consisting of specific visual, auditory, tactual, and olfactory cues. The saccharin aversion was then extinguished in a context free from conditioning-context cues. Later, saccharin preference tests were given in the presence and absence of these cues. The results indicated that the background cues of the conditioning trial controlled the amount of saccharin drunk on extinction trials, and, furthermore, that extinction of the taste aversion was context specific; i.e., groups given extinction trials in a different (from conditioning) context retained their saccharin aversion in the conditioning context only. The results indicate an important role played by the exteroceptive context in taste-aversion conditioning.

A reconstructive-processing interpretation of the recognition failure phenomenon ☆

Abstract The generality of the recognition failure phenomenon was the primary basis for the present research. It was hypothesized that the phenomenon obtains whenever an insufficient degree of compatibility exists between the task demands at recognition and those present during study. Experiments 1 and 2 demonstrated that, despite a recognition task that was incompatible to conditions of encoding, subjects could actively reconstruct aspects of the initial situation, and hence recognition failure was minimized. It was assumed that the stimulus material — categorized word pairs — facilitated this reconstructive process. Experiment 3 was designed specifically to examine further the reconstructive process as well as recognition failure. The results indicated that (a) the nature of this process could be mathematically predicted, and (b) subjects seldom failed to recognize words they recalled. The results of the present study strongly suggest an important boundary condition of the phenomenon of recognition failure. Moreover, Tulving and Wisemans (1975) quadratic function could not predict accurately the obtained magnitude of recognition failure.

High‐Frequency Positive‐Pressure Ventilation (HFPPV) During Transthoracic Resection of Tracheal Stenosis and During Peroperative Bronchoscopic Examination

Operation of a patient with intrathoracic tracheal stenosis using a new ventilation technique (HFPPV) is described. The technique permits tracheoscopy during ventilation and operation, thus enabling exact location of the stenosis to be obtained. Further, peroperative tracheoscopic checking of the anastomosis can be carried out. Resection and anastomosis can be performed without interference of a bulky endotracheal tube.

EXTEROCEPTIVE CONTEXT IN TASTE-AVERSION CONDITIONING AND EXTINCTION: ODOUR, CAGE, AND BOTTLE STIMULI.

Five experiments investigated the extent to which the exteroceptive context, present on a saccharin aversion conditioning trial with rats, controlled the resulting aversion on one-bottle extinction tests and subsequent preference tests. The presence or absence of the specific odour which had been present on the conditioning trial was found not to influence saccharin intake on extinction tests, whereas the presence of the particular compartment in which, and the bottle from which, the saccharin had been consumed greatly suppressed saccharin intake as compared to the absence of these elements. Preference tests, performed in the respective conditioning contexts, showed extinction to be specific to the compartment + bottle context: groups that had extinguished their saccharin aversion in a context different from the conditioning context, retained their aversion in the conditioning context. No such specificity was found for the odour context. However, in the absence of the taste stimulus during the extinction phase, the odour that had been present on the conditioning trial did control the amount of water consumed, whereas the compartment+bottle context did not. Moreover, on preference tests, groups that had consumed water during extinction in the presence of the odour context, evidenced a lesser saccharin aversion than groups not exposed to the odour. The results are interpreted as demonstrating that rats learn about taste, odour, cage and bottle stimuli on a taste-aversion conditioning trial, and that taste and bottle stimuli seem to be the most salient.

Physiologic Evaluation of the HFPPV Pneumatic Valve Principle and PEEP An Experimental Study

In experiments in dogs the ventilatory and circulatory conditions prevailing with the ventilatory pattern in high‐frequency positive‐pressure ventilation (HFPPV) were investigated with use of a pneumatic valve principle and a ventilator system of an “open” character. Keeping the gas input constant the importance of insufflation frequency and insufflation time and the reactions to various levels of positive end‐expiratory pressure (PEEP) were investigated in terms of changes in arterial pH, Pco2and Po2.

High‐Frequency Positive‐Pressure Ventilation (HFPPV) Applied in Bronchoscopy under General Anaesthesia An Experimental Study

Techniques for ventilation in bronchoscopy under general anaesthesia using intermittent positive‐pressure ventilation directly via the fixed side‐arm of the open bronchoscope have recently been described by several authors. Our present technique utilizes a high pressure oxygen/nitrous oxide gas mixture which is obtained from a gas‐conditioning system. This gas is intermittently supplied at a high insufflation frequency to the side‐arm of the open bronchoscope.

Processing and storage explanations of the modality effect

Abstract A mixed-mode paradigm was used to evaluate two explanations of the modality effect, i.e. the superior short-term retention of auditorily as opposedto visually presented information. The ‘processing notion’ , postulating a larger processing capacity for auditorily presented information gained no support by the present data. The‘storage notion’, postulating a larger storage capacity for a hypothetical auditory as opposed to a hypothetical visual store, was clearly supported by the data. Overall mixed-mode performance and between-modality differences were the measures used in the evaluation proper. The general conclusion of the present study was that the storage notion constitutes a promising beginning towards a broader understanding of the modality effect.

Speed and accuracy in scanning as a function of combinations of text and background colors

An experiment is reported which employed a method of scanning matrices of letters for specific targets. The color of the letters and the color of the background varied. Scanning time was one dependent variable and accuracy in detecting the correct number of targets in each matrix was another. The results showed a relatively close correspondence between scanning time and the rating data of the same color combinations in an earlier study. With respect to accuracy, the present experiment showed that the overall error rate was extremely low.

High‐Frequency Positive‐Pressure Ventilation (HFPPV) in Neonates and Infants during Neuroleptal Analgesia and Routine Plastic Surgery, and in Postoperative Management

The low pulmonary compliance, the high airway resistance and the “rapid” breathing pattern of neonatal and paediatric patients make it necessary to design special ventilators to match the pulmonary physiology of infants.

THE EFFECT OF MONETARY REWARD AND PUNISHMENT ON THE REPETITION OF RESPONSES UNDER OPEN AND CLOSED TASK CONDITIONS

Subjects were given one study and two test trials on a list of paired associates. Critical responses on the first test were those which were rewarded or punished by gain or withdrawal of money. Between subjects variables were (a) whether the critical responses on test 1 were right or wrong, and (b) whether subjects were informed of the second test before or after test 1. On test 2, subjects were asked to repeat their test 1 responses to the appropriate stimuli. When subjects were unaware that they would receive a second test, rewarding a response on test 1 increased its probability of repetition on test 2; punishment had no significant effect. When subjects were aware that they would be tested again, the reward/ punishment treatment had no effect. An explanation based on the Law of Effect is rejected in favour of a cognitive explanation, utilizing the total time hypothesis.