Massey Documents by Type

Permanent URI for this communityhttps://mro.massey.ac.nz/handle/10179/294

Browse

Filters

1981 - 198912010 - 20161

Settings

Subject: search.filters.subject.Disinhibition

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Exploring the relationship between dietary patterns, eating behaviour and fat taste detection thresholds : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Science in Nutrition and Dietetics at Massey University, Albany, New Zealand
    (Massey University, 2016) Henderson, Lisa
    Background: Dietary pattern analysis provides a unique opportunity to explore combinations of food intake in conjunction with factors known to affect dietary intake. Fat taste sensitivity is an emerging correlate of dietary intake and, when impaired, has a proposed role in the dysregulation of dietary intake and eating behaviours. Aim: To investigate dietary patterns, eating behaviours and fat taste detection thresholds in a group of New Zealand European women aged 19-45 years and identify associations between these factors. Methods: Fifty post-menarche, pre-menopausal New Zealand European (NZE) women, (18-40 years) completed a partially validated, semi-quantiative 220-item food frequency questionnaire and a validated Three-factor eating questionnaire. Height and weight were measured to calculate body mass index (BMI) (kg/m2) and a bioeletrical impedence analysis (BIA) was completed to measure body fat percentage (BF%). During sensory testing protocol participants were exposed to increasing concentrations of ultra-heat treatment (UHT) milk/oleic acid (OA) solutions using the three alternative forced choice method (3-AFC). A naïve OA detection threshold was determined at the point where the participant identified the OA solution correctly three times at the same concentration. Dietary patterns were determined using principal component factor analysis. Associations between dietary pattern scores, taste sensitivity, eating behaviour and baseline characteristics were investigated. Results: Three dietary patterns were identified: ‘unhealthy’, ‘healthy’ and ‘snacking’. Most women had low eating behaviour scores for cognitive restraint (90%) and disinhibition (74%). Hunger scores were comparatively higher, only 40% had low scores. Twenty-three participants (46%) were classified as hypersensitive and 54% were hyposensitive to OA taste. ‘Unhealthy’ pattern scores were inversely associated with cognitive restraint (r=.391, P=.005) and positively associated with age (r=.297, P=.036). ‘Healthy’ pattern scores were positively associated with cognitive restraint (r=.418, P=.003), OA taste detection thresholds (r=0.446, P=.001) and BMI (r=.325, P=.021). Women with low ‘snacking’ pattern scores were significantly older (31.7 years (24.7, 40.4)) than those with moderate scores (24.0 years (22.0, 28.1)) (P=.037). No relationship was found between OA taste detection thresholds and eating behaviour. Conclusion: Participants in this study showed a significant link between habitual dietary intake and measures for eating behaviour and fat taste sensitivity. Both ‘healthy’ and ‘unhealthy’ dietary patterns were associated with one, or both, of these factors. An unexpected positive association between the ‘healthy’ dietary pattern and fat taste sensitivity indicates a need for further investigation to better understand this relationship. Findings from the current study support the use of dietary patterns to better represent habitual intake in future research investigating fat taste sensitivity or eating behaviour. Key words: Habitual intake, dietary intake, fat taste sensitivity, cognitive restraint, disinhibition, hunger
  • Thumbnail Image
    Item
    Disinhibition in human vision : being a thesis submitted as a partial requirement for the degree of Master of Science with Massey University
    (Massey University, 1981) Scheirlinck, Joanne Gemma Maria
    Recent electrophysiological and psychophysical data have suggested that within the human visual system there exists specialised neural units which respond maximally to specific orientations. This suggestion is based upon electrophysiological data recorded from orientation specific neurons in the cortex of the cat and monkey, and psychophysical studies of normal observers. Following a review of this literature three psychophysical paradigms (masking, aftereffect, and dichoptic aftereffect) were utilized to investigate disinhibition of orientation analyzers in humans. Chapter two examined the spatial selectivity of the disinhibition function with successive presentation of two masking gratings. The results indicated that, for a vertical test stimulus, disinhibition was maximal when the orientations of M1 and M2 were similar and was minimal when the orientational difference was greater than 15 deg. Chapter three investigated disinhibition in the orientation aftereffect, following both successive and simultaneous presentation of two adaptation gratings. The results showed that regardless of the temporal sequencing the addition of a second grating could either disinhibit or summate the magnitude of the aftereffect. Generally, interaction was maximal when when the orientation difference between the gratings was 15 deg. Dichoptic presentation of stimuli (chapter four) demonstrated that orientation disinhibition may be a high level effect at least parallel to that of binocular rivalry. The results indicated firstly that disinhibition and summation were maximal when the orientation difference between the gratings was 15 deg and secondly that these functions could not be disrupted by binocular rivalry. The results of this thesis are in keeping with a lateral inhibition explanation of orientation disinhibition. This lateral inhibition system is consistent with a general feature detection model of visual perception which is known to exist in humans.