PROTOCOL

PROPOSED STUDY: Salience of Visual Parts

PRINCIPAL INVESTIGATOR: Donald D. Hoffman, Professor of Cognitive Science

1. PURPOSE OF THE RESEARCH.

This project is a multidisciplinary investigation of the perception of visual objects. In particular it focuses on the perception of the parts of objects. The objective is (1) to further the theoretical and empirical understanding of this important aspect of human visual cognition and (2) to further the practical application of this understanding to automated machine vision systems. The method is (1) to apply principles from mathematics and physics in order (2) to predict the processes underlying the visual perception of surfaces; (3) use these predictions to formulate critical visual demonstrations and psychophysical experiments; (4) use the experimental results to constrain machine vision and neural network models of the process of surface recovery. We anticipate that these studies will (1) lead to a better understanding of how the shape partitioning process in human vision interacts with the processes that determine the choice of figure and ground, (2) illuminate the dependence of phenomenal transparency on shape partitioning processes, (3) enhance our understanding of object recognition by human vision, and (4) enhance our understanding of visual deficits that might arise in Alzheimer’s Disease.

2. BACKGROUND OF THE INVESTIGATOR.

For the past 15 years the Donald D. Hoffman has been engaged in psychophysical testing of computational models of perception.

Dr. William R. Shankle is an Adjunct Associate Professor of Cognitive Science at UCI and a former director of the Alzheimer’s Clinic at UCI.

Dr Junko Hara is a postdoctoral researcher in ICS at UCI. Her background is in mathematical modeling, neural networks, and image processing.

Colleen Nilson is a graduate student in Cognitive Sciences working with Professor Hoffman doing research on human vision.

3. RESEARCH PLAN.

Experiments are conducted in which subjects observe displays on computer monitors and make judgments about some characteristics of the displays, e.g., regarding the salience of parts, or the appearance of figures against background. Subjects are generally run in one hour sessions, with a maximum of six sessions per week.

4. SUBJECTS.

Subjects are taken from the Social Science pool, or are recruited from the Social Science graduate student body, or are Alzheimer’s patients. The patients will come from Dr. Shankle's community based dementia practice, located at 500 Newport Center Dr., Suite 197, Newport Beach, CA 92660. All patients have been diagnosed using NINDS-ADRDA criteria for Probable and Possible Alzheimer's Disease, as well as ADDTC criteria for Probable and Possible Vascular Dementia. Since this is a community based dementia program, it does not suffer from much of the selection bias of tertiary referral centers. Dr. Shankle currently manages approximately 400 patients with various etiologies of dementia at all stages of the disease. Each patient is seen at three to six months intervals and has a complete set of laboratory and imaging data in order to comply with standardized diagnostic criteria. Patients who fulfill selection criteria will be offered the opportunity to participate in the research study. This research study will be fully discussed with responsible family members, who always accompany the patient during office visits. Informed consent will be required from both the patient and at least one responsible family member, which is typically a spouse taking care of their counterpart. Occasionally, children of the patient are the responsible family member when a spouse has died. At other times, a responsible family member will consist of a brother or sister of the patient.

As former director of the Alzheimer's Clinic at UCI, Dr. Shankle has been involved in many research protocols. In order to insure that subjects are fully aware of what they are consenting, the research protocol will be reviewed with both the patient and their responsible family members. A patient will be enrolled to our study of their visual perceptual abilities if two conditions are satisfied:

1. The responsible family member/caregiver agrees that it is a good idea and is safe for the patient to participate in our study. If the patient has already assigned power of attorney for health and property decisions to a family member/caregiver, then that person must agree to allow the patient to participate in our research study.

2. The patient, after adequate consultation with the responsible family members, also agrees to participate in the research study.

The issue of competency usually arises in moderate to severely demented subjects. In most mildly demented subjects, they will be able to understand the purpose of the study (to study their ability to perceive shapes and forms), and the fact that there is no medical risk for them to be involved. They will simply be looking at objects and responding to them in order to determine their visual-perceptual abilities.

In moderate to severely demented subjects, they may have difficulty understanding the research study even though its purpose is simple. It is in this case where it is essential that the legally responsible family member consider it desirable and safe for the patient to participate in the research study. In situations where the responsible family member/caregiver desires the patient to participate in the study, but the patient does not appear to fully understand the purpose of the study, they will be excluded.

In order to determine whether a patient is able to understand the purpose of the research study, they must be able to comprehend single sentences. Comprehension for multiple step commands is routinely measured on all subjects by Dr. Shankle. Patients who can follow at least two step commands have adequate comprehension to understand the purpose of the study.

5. RISKS/DISCOMFORTS/INCONVENIENCES.

There are no known risks. There are no discomforts or inconveniences beyond those encountered in any ordinary sedentary attentive activity of limited (up to one hour) duration.

6. BENEFITS.

(1). There will be no direct benefit to subjects.

(2) There are expected scientific contributions to the study of perception, in particular to the study of the human visual perception of surfaces as described in 1 above.

7. MEASURES TAKEN TO PROTECT THE RIGHTS AND WELFARE OF SUBJECTS.

The names of subjects will not appear on any data sheets. Any information derived from thisresearch project that personally identifies a subject will not be voluntarily released or disclosed without the subject’s consent, except as specifically required by law.

8. COMPENSATION.

For some experimental subjects (from the Social Science pool) will receive course credit or no compensation. Graduate student subjects will be paid at a rate of approximately $10 per hour or receive no compensation. Subjects that agree to be paid or credited will be paid or credited for all sessions for which they appear, whether or not the study is completed. Alzheimer’s patients will not be paid.