Biomedical subjects
Publications and source records attributed to J Hogg.
Six patients have been treated for chronic alcoholic pancreatitis by total obstruction of the pancreatic duct. In each instance the pancreatic duct was of near normal calibre, and any other procedure would have involved pancreatic resection. There has been little morbidity, and three of six cases have had complete pain relief.
A classical conditioning procedure was used with five profoundly retarded children with multiple handicaps in order to investigate basic learning processes in such children. Their chronological ages ranged from 48 to 108 months and their mental ages from 0 to 5.5 months. The procedure used a sound as the conditioned stimulus, a puff of air to the cornea as the unconditioned stimulus, and eye-blink as the conditioned response. Conditioning was established for the two most developmentally advanced children, and the intermediate pair showed different patterns of orienting response to the conditioned stimulus but no evidence of conditioning. The fifth and most developmentally delayed child did not respond to the stimuli. The extent to which these results can be generalised to the conditioning of profoundly retarded, multiply handicapped children is discussed.
Architects and non-architects made Semantic Differential ratings of colour samples (chips) and a simulated interior space (a model). In analyses of the total samples' ratings (architects and non-architects) of (a) colour chips and (b) models, and individual sample analyses, (c) architects' chip judgements, (d) architects' model judgements, (e) non-architects' chip judgements, and (f) non-architects' model judgements, five factors occurred, though not necessarily all in any one analysis. These were: (i) dynamism; (ii) spatial quality; (iii) emotional tone; (iv) evaluation; (v) complexity. Linear correlations between parameters of the Munsell Color System and the above factors in the various analyses were calculated, while parallel analyses were carried out employing a graphical technique described by Sivik (1974a) involving isosemantic maps. In all analyses, linear correlations between the colour parameters and judgements were found for the dynamism factor, spatial quality factor, and emotional tone factor. They were associated respectively with chroma, value, and hue. Inspection of the isosemantic maps indicated subsidiary effects of the non-dominant dimensions of a non-linear sort, though the maps also exhibited the linear relations. Linear correlations were low or non-existent for the evaluation and complexity factors, and the complex nature of their determinants was clear from the isosemantic maps. The dterminants of judgements were similar for architects and non-architects, with the exception of evaluative judgements for the models in which markedly different determinants were noted. Comparability of the present findings with other studies carried out in a variety of countries over a 20 year period was high for dynamism, spatial quality, and emotional tone, and it is suggested that there may be something inherent in the response to colour in relation to such judgements. Recent physiological work is discussed, and its limitations in terms of colours sampled and an overconcentration on the hue dimension noted. In contrast, it is suggested that dimensions of judgement, such as evaluation or complexity, reflect to a greater extent culture or training, and are hence independent of the basic colour attributes.
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Profoundly retarded multiply handicapped children were placed in a situation where auditory stimulation was made contingent on a visually directed level-pulling response. Two experiments were performed. In the first, a technique for establishing an effective reinforcer from a range of possible reinforcing stimuli was evaluated. In the second experiment, a multiple schedule was used to compare the effectiveness of a reinforcer whose efficacy was established in Experiment 1 with a second auditory stimulus. The selection of auditory reinforcers and an evaluation of their relative potency was achieved using these techniques. The results show the feasibility of systematic measurement of operant-conditioning effects with very severely handicapped subjects in a laboratory situation. The information gained concerning the effectiveness of auditory reinforcers has implications for behavior-modification programs with these children.
Ten dogs have been used in a study which demonstrates the feasibility of producing total pancreatic duct obstruction with alkyl-alpha-cyanoacrylate glue. Low pressure injection of glue into the pancreatic duct has led to a reproducible pancreatic atrophy with preservation of the islets. A sharp rise in serum amylase was noted in each dog, but at autopsy examination at monthly intervals after the operation, no evidence of chronic pancreatitis was observed. None of the dogs was rendered diabetic. The success of the experimental technique raises the possibility that such a technique might be useful in the management of human chronic pancreatitis as an alternative to pancreatic resection, and the operation has been performed on three patients so far.
We studied the determinants of maximal expiratory flow in 7 patients in whom surgical lung specimens showed evidence of mild emphysema or obstruction of the peripheral airways. All the patients showed frequency dependence of dynamic lung compliance and low maximal expiratory flow. Lung elastic recoil pressures were reduced at all lung volumes in 4 of 5 patients with emphysema but were normal in 2 patients with obstruction of the peripheral airways. Maximal flow-static recoil curves showed a high intercept in the pressure axis when the slope between 50 per cent and 30 per cent of vital capacity was extrapolated to zero flow (transmural pressure in the flow-limiting segment) in all patients. The slope of these curve represents the conductance of the segment that extends from the alveoli to the flow-limiting segment and includes the latter. Conductance of this segment was higher than normal in 4 patients with emphysema and borderline low in one, and low in one patient with obstruction of the peripheral airways and borderline low in the other. Increased transmural pressure in the flow-limiting segment was interpreted as being due to peripheral location of collapsible flow-limiting segment and, in part, limiting maximal expiratory flow. The results also suggested that flow limitation in emphysema may occur without physiologic evidence of increased resistance of peripheral airways when, in fact, bronchiolitis is present on histologic examination.
The use of discrimination learning paradigms in the study of attentional transfer is discussed. The technique of go/no-go discrimination learning followed by stimulus generalization testing is contrasted with the more familiar simultaneous learning paradigm followed by a shift in the relevant cues. In the former paradigm the effect of training a discrimination on one dimension on the slope of the stimulus generalization gradient on an independent gradient dimension (extra-dimensional training) is assessed. A steepening of the gradient relative to appropriate control procedures is taken as evidence of positive attentional transfer. The relevance of the technique to the detailed study of attentional transfer in educationally subnormal (severely) (ESN(S)) children is considered. In Expt. I nine ESN(S) children were trained in a go/no-go discrimination involving stimuli differing in orientation, and were generalization tested on a dimension that was orthogonal, namely hue. Of the six subjects who learnt the discrimination five showed clear decremental gradients on the hue dimension. In contrast a Pseudo-Discrimination group (PD) of eight subjects matched to those in the TD group showed no gradients. These subjects were not trained in the orientation discrimination, but were reinforced for responding on 50 per cent of each of the S+ and S- stimulus presentations. They thus received equal exposure to, but no differential training on, the orientation dimension. An S+ only group of four subjects who received no exposure to the orientation stimuli showed no gradients when stimulus generalization testing on the hue continuum was carried out. The result is discussed in terms of transfer deriving from stimulus control by relational aspects of the stimuli; in terms of control by constant irrelevant stimuli; and in terms of the study of stimulus control in ESN(S) children. In Expt. II the influence of the codability of the colours on the location of the peak of the stimulus generalization gradients in the TD group is investigated.
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