We have a number of projects that seek to apply advanced signal detection theory to the sensory evaluation of foods and beverages.
We are currently investigating the use of the A Not-A, 2AFC, same-different, and various reminder tasks in sensory evaluation.
We seek to understand how judges' decisions decisions impact on the measurement of their performance, and how context influences the operational power of different tasks.
Key Researcher: Miriam Stocks
Auditory Neuroscience and Autistic Spectrum Disorder
Time-shifted dichotic pitch is a percept that is generated solely by the timing difference between the arrival of a sound at each ear.
This stimulus therefore provides an opportunity to study neural mechanisms associated with timing differences, and also with the segregation of auditory objects.
We are currently investigating differences in the perception (and EEG correlates) of dichotic pitch between individuals with Autistic Spectrum Disorder and matched controls.
Key Researcher: Veema Lodhia
Taxonomy of Psychophysical Tasks
We are keen to develop a classification tree for psychophysical discrimination procedures. This project is in the early stages of development.
The idea is to develop a selection system for the ‘best’ psychophysical procedure to use under a range of contextual conditions.
In Food Science these could include the type of product, purpose of the procedure, or the practical number of tests that can be conducted before fatigue or adaptation make continuing impractical.
Key researcher: Miriam Stocks
We are keen to discover some of the electrophysiological correlates (EEG and other markers) of noise sensitivity; a characteristic of individuals who are more affected by ‘noise’ than others. Such noises can be produced, for example, by traffic or other environmental sources.
We are currently using noise sensitivity questionnaires to select our participants, and then investigating differences is alpha activity between groups when exposed to sounds ‘annoying’ to different degrees.
Key researchers: Dr Daniel Shepherd; Jenny Lee; Oleg Medvedev
Consider a list of words read to a person, with some of the words read by a man and others by a woman. After a period, the person is shown a list of words, half of which were read out earlier (old words) and half of which were not (new words).
The person indicates how confident they are that each word is old or new (the old-new task) and must also indicate whether the word was originally read out by a man or woman (the source task).
It turns out that performance on the source task is conditional on performance in the old-new task. We are developing models to account jointly for old-new and source memory judgements.
Key researcher: Associate Professor Michael Hautus
Olfactory Threshold Assessments
We are also investigating the strengths and weaknesses of various methods for measuring olfactory thresholds. Unlike for the study of thresholds in the other senses, olfactory thresholds must be assessed with a small number of test replications.
This is due to practical considerations, such as the time it takes to conduct a single test, and physiological considerations, such as the rapid adaptation that occurs in the olfactory system.
We are comparing various classical approaches (such as ASTM E679) with adaptive psychophysical methods, such as the transformed up-down method in conjunction with Sniffin’ Sticks.
Key researchers: Mei Peng; Amber McClelland