Julian Breeze | Bangor University (original) (raw)

Papers by Julian Breeze

Journal of Medical Imaging and Health Informatics, , Feb 1, 2015

This study examined whether ECG and physiological findings recorded during the stress component o... more This study examined whether ECG and physiological findings recorded during the stress component of cardiac 99mTc Sestamibi gated SPECT (single photon emission computed tomography) imaging add to the interpretation of the examination. 311 patients (161 male), mean age 66 years (range 31–89 years) were categorized as having myocardial perfusion either within the normal range expressed as the MyoQuant Index, (MQI ≤ 1) or abnormal perfusion (MQI > 1). Based on results from the continuous 12 lead ECG examination taken during the stress component of this examination, patients were determined to have either ST depression (ST-pos ≥ 1 mm) or no T changes (ST-neg) 42% of these patients showed ST depression greater than 1 mm. The results show no overall correlation between ST depression and abnormal perfusion. Examination of left ventricular cavity volumes and ejection fraction at rest and cardiovascular haemodynamics (systolic blood pressure, diastolic blood pressure, heart rate) at rest and during stress were carried out. Analysis of this data showed no significant difference between the groups, except for an effect, (p < 01), on the resting heart rate of patients (ST-pos, 86 bpm. (beats per minute). vs. ST-neg, 79 bpm.) and the maximal heart rate (p < 05) (ST-pos 126 bpm. vs. ST-neg. 119 bpm.). This suggests that the heart rate of patients should be recorded in this type of examination. Patients with a positive stress test result, and a completely normal perfusion rating, (MQI < 1) accounted for 9% of the total cohort (n = 29, 6 male).

Medical Imaging in Clinical Practice, Feb 20, 2013

Acta Psychologica, Jan 1, 2012

It is common to use verbal instructions when performing complex tasks. To evaluate how such instr... more It is common to use verbal instructions when performing complex tasks. To evaluate how such instructions contribute to cognitive control, mixing costs (as a measure of sustained concentration on task) were evaluated in two task-switching experiments combining the list and alternating runs paradigms. Participants responded to bivalent stimuli according to a characteristic explicitly defined by a visually presented instructional cue. The processing of the cue was conducted under four conditions across the two experiments: Silent Reading, Reading Aloud, Articulatory Suppression, and dual mode (visual and audio) presentation. The type of cue processing produced a substantial impact on the mixing costs, where its magnitude was greatest with articulatory suppression and minimal with reading aloud and dual mode presentations. Interestingly, silently reading the cue only provided medium levels of mixing cost. The experiments demonstrate that relevant verbal instructions boost sustained concentration on task goals when maintaining multiple tasks.

Journal of Clinical and Experimental Neuropsychology, Apr 26, 2011

It has been shown that high-schizotypy and schizophrenic participants demonstrate increased task-... more It has been shown that high-schizotypy and schizophrenic participants demonstrate increased task-switching costs, although high-schizotypy participants present this pattern only in incongruent trials (Cimino & Haywood, 2008). In this study, we aim to explore whether this results from difficulties in selective attention or task control. A total of 18 participants with high levels of psychometrically defined schizotypy and 16 participants with low scores were tested in two different versions of a task-switching paradigm. Participants were asked to switch between attending to the color or the shape of bidimensional objects following a previous cue. Two versions of the task were investigated, one involving only switches in the perceptual dimension to attend (color or shape) and another also switching the response set. High-schizotypy subjects consistently showed increased switch costs in incongruent trials for both versions of the tasks, demonstrating a deficit in the selection of the perceptual dimension instead of the selection of the response rules.

The aim of this thesis is to understand and explain some of those processes involved in the selec... more The aim of this thesis is to understand and explain some of those processes involved in the selection of appropriate tasks and ultimately in selecting the correct responses to those tasks. With a focus on the interference and conflict that occurs both at the perceptual and action selection stages when switching task. It should be possible to demonstrate with increases to the number of attributes, the experience of tasks associated with non-target attributes, and in varying the number of trials before switching tasks that task selection consists of several stages or processes, and will show how these processes do not necessarily interact. This will show that the switch cost is not an unitary cost associated with changing a single response-stimulus setting, task parameter, or an overall task set, but a composite of various costs associated with different task selection processes.

Talks by Julian Breeze

The seat of the soul and the control of voluntary movement -in fact, of nervous functions in gene... more The seat of the soul and the control of voluntary movement -in fact, of nervous functions in general, -are to be sought in the heart. The brain is an organ of minor importance.

Measures the uptake of a tracer (Thallium-201) injected into the blood, the amount absorbed into ... more Measures the uptake of a tracer (Thallium-201) injected into the blood, the amount absorbed into the myocardium (heart muscle) indicates any ischemia.

Journal of Medical Imaging and Health Informatics, , Feb 1, 2015

This study examined whether ECG and physiological findings recorded during the stress component o... more This study examined whether ECG and physiological findings recorded during the stress component of cardiac 99mTc Sestamibi gated SPECT (single photon emission computed tomography) imaging add to the interpretation of the examination. 311 patients (161 male), mean age 66 years (range 31–89 years) were categorized as having myocardial perfusion either within the normal range expressed as the MyoQuant Index, (MQI ≤ 1) or abnormal perfusion (MQI > 1). Based on results from the continuous 12 lead ECG examination taken during the stress component of this examination, patients were determined to have either ST depression (ST-pos ≥ 1 mm) or no T changes (ST-neg) 42% of these patients showed ST depression greater than 1 mm. The results show no overall correlation between ST depression and abnormal perfusion. Examination of left ventricular cavity volumes and ejection fraction at rest and cardiovascular haemodynamics (systolic blood pressure, diastolic blood pressure, heart rate) at rest and during stress were carried out. Analysis of this data showed no significant difference between the groups, except for an effect, (p < 01), on the resting heart rate of patients (ST-pos, 86 bpm. (beats per minute). vs. ST-neg, 79 bpm.) and the maximal heart rate (p < 05) (ST-pos 126 bpm. vs. ST-neg. 119 bpm.). This suggests that the heart rate of patients should be recorded in this type of examination. Patients with a positive stress test result, and a completely normal perfusion rating, (MQI < 1) accounted for 9% of the total cohort (n = 29, 6 male).

Medical Imaging in Clinical Practice, Feb 20, 2013

Acta Psychologica, Jan 1, 2012

It is common to use verbal instructions when performing complex tasks. To evaluate how such instr... more It is common to use verbal instructions when performing complex tasks. To evaluate how such instructions contribute to cognitive control, mixing costs (as a measure of sustained concentration on task) were evaluated in two task-switching experiments combining the list and alternating runs paradigms. Participants responded to bivalent stimuli according to a characteristic explicitly defined by a visually presented instructional cue. The processing of the cue was conducted under four conditions across the two experiments: Silent Reading, Reading Aloud, Articulatory Suppression, and dual mode (visual and audio) presentation. The type of cue processing produced a substantial impact on the mixing costs, where its magnitude was greatest with articulatory suppression and minimal with reading aloud and dual mode presentations. Interestingly, silently reading the cue only provided medium levels of mixing cost. The experiments demonstrate that relevant verbal instructions boost sustained concentration on task goals when maintaining multiple tasks.

Journal of Clinical and Experimental Neuropsychology, Apr 26, 2011

It has been shown that high-schizotypy and schizophrenic participants demonstrate increased task-... more It has been shown that high-schizotypy and schizophrenic participants demonstrate increased task-switching costs, although high-schizotypy participants present this pattern only in incongruent trials (Cimino & Haywood, 2008). In this study, we aim to explore whether this results from difficulties in selective attention or task control. A total of 18 participants with high levels of psychometrically defined schizotypy and 16 participants with low scores were tested in two different versions of a task-switching paradigm. Participants were asked to switch between attending to the color or the shape of bidimensional objects following a previous cue. Two versions of the task were investigated, one involving only switches in the perceptual dimension to attend (color or shape) and another also switching the response set. High-schizotypy subjects consistently showed increased switch costs in incongruent trials for both versions of the tasks, demonstrating a deficit in the selection of the perceptual dimension instead of the selection of the response rules.

The aim of this thesis is to understand and explain some of those processes involved in the selec... more The aim of this thesis is to understand and explain some of those processes involved in the selection of appropriate tasks and ultimately in selecting the correct responses to those tasks. With a focus on the interference and conflict that occurs both at the perceptual and action selection stages when switching task. It should be possible to demonstrate with increases to the number of attributes, the experience of tasks associated with non-target attributes, and in varying the number of trials before switching tasks that task selection consists of several stages or processes, and will show how these processes do not necessarily interact. This will show that the switch cost is not an unitary cost associated with changing a single response-stimulus setting, task parameter, or an overall task set, but a composite of various costs associated with different task selection processes.

The seat of the soul and the control of voluntary movement -in fact, of nervous functions in gene... more The seat of the soul and the control of voluntary movement -in fact, of nervous functions in general, -are to be sought in the heart. The brain is an organ of minor importance.

Measures the uptake of a tracer (Thallium-201) injected into the blood, the amount absorbed into ... more Measures the uptake of a tracer (Thallium-201) injected into the blood, the amount absorbed into the myocardium (heart muscle) indicates any ischemia.