Dennis P. Carmody

Visual scanning, pattern recognition and decision-making in pulmonary nodule detection.

Eye movements were recorded while four subjects searched a set of 60 films, 24 normal and 36 abnormal for pulmonary nodules. Error rates, scanning patterns and the dwell time of fixation clusters on normal and nodule-containing areas of the film were studied. Using the assumption that prolonged dwell time indicates intensive processing of visual data, a model was developed for nodule detection that includes four steps: orientation, scanning, pattern recognition and decision-making. False-negative errors were divided into three classes: scanning errors, recognition errors and decision-making errors. Of 20 false-negative errors, 30% were considered scanning, 25% recognition and 45% decision-making.

Psychometric characteristics of the Beck Depression Inventory-II with college students of diverse ethnicity

Introduction To evaluate the psychometric characteristics of the Beck Depression Inventory – Second Edition (BDI-II) with an ethnically diverse sample of college students. Methods The BDI-II was completed by a group of 502 college students (54% women) with an ethnic distribution of African-American (n=49, 10%), Asian-American (n=33, 7%), Hispanic (n=113, 22%), Native-American (n=10, 2%), and White (n=297, 59%). Psychometric characteristics of the inventory with the ethnically diverse group were compared to the results published in the test manual for nonclinical samples composed predominantly of European and White participants. Results Using confirmatory factor analyses, a three-factor model that identified negative attitude, performance difficulty, and somatic dimensions, provides a better fit of the data than does the two-factor model. Similar psychometric characteristics were found between the ethnically diverse student sample and the standardization sample. Based on multivariate analysis of variance, White students had higher scores on the item of agitation compared to Asian-American students and on the items of worthlessness and irritability compared to Hispanic students. Conclusion The results of the psychometric analyses suggest that the BDI-II is suitable as a screening instrument for depression in college populations of diverse ethnicity.

An analysis of perceptual and cognitive factors in radiographic interpretation.

Detection of small tumors in chest x-ray films was studied under tachistoscopic viewing conditions designed to simulate single fixations varying in dwell time, found in free search. Two questions were asked: How much dwell time is required to detect a nodule (experiment 1)? How effective are peripheral inputs in the detection of a nodule (experiment 2)? Our findings indicate that a dwell time of 300 ms was sufficient to detect 85% of the nodules when they were viewed directly. Detection accuracy was reduced by one-half when the tumor was located 5° from the axis of gaze. Taken together with data from eye movement experiments, these results provide useful estimates of perceptual and cognitive parameters of visual search.

Efficacy of Traumatic Brain Injury Rehabilitation: Interventions of QEEG-guided Biofeedback, Computers, Strategies, and Medications

The onset of cognitive rehabilitation brought with it a hope for an effective treatment for the traumatic brain injured subject. This paper reviews the empirical reports of changes in cognitive functioning after treatment and compares the relative effectiveness of several treatments including computer interventions, cognitive strategies, EEG biofeedback, and medications. The cognitive functions that are reviewed include auditory memory, attention and problem solving. The significance of the change in cognitive function is assessed in two ways that include effect size and longevity of effect. These analyses complement the previously published meta-reviews by adding these two criteria and include reports of EEG biofeedback, which is shown to be an effective intervention for auditory memory.

Traumatic Brain Injury Rehabilitation: QEEG Biofeedback Treatment Protocols

Interventions for improvement of cognitive problems in patients with traumatic brain injury (TBI) include electroencephalography biofeedback, also known as neurofeedback. Quantitative electroencephalography (QEEG) patterns are assessed in TBI patients and then compared to a database obtained from a normative population. Deviations in QEEG patterns from the normative group are the basis for an intervention plan. While QEEG patterns, obtained under an eyes closed, resting condition, provide information about deviations at rest, QEEG patterns obtained while the patient engages in cognitive tasks reflect specific deficiencies in brain functioning. This paper reviews and assesses QEEG patterns collected under both resting conditions as well as cognitive tasks. The article provides a theoretical and empirical base for QEEG interventions with TBI.

Nodule detection with and without a chest image.

The detectability of nodules displayed on uniform backgrounds was compared with their detectability on chest images by using receiver operating characteristic (ROC) curves. The images were displayed using a digital television system. Two conditions, chest image and uniform background, were compared at three different levels of added random noise. The viewing conditions were made as similar as possible by setting the luminance of the uniform background equal to the luminance of the lung in the chest image. Nodule detectability was significantly lower for the chest image than for the uniform background at each level of added random noise. The anatomic structure of the chest image interferes with the structural integrity of the nodule image resulting in lower detection performance.

Comparison scans while reading chest images. Taught, but not practiced.

Radiology instructors and residents were surveyed for their methods of instruction concerning viewing techniques. A similar group of radiologists had their eye activity measured as they viewed chest images. Image reading techniques are taught to be systematic and directive with comparisons of bilateral features. Yet, most images are read by a free search method; bilateral comparisons comprise less than 4% of the visual activity. Instructors and residents show this discrepancy between instructional techniques and reading practice.

Self-Representation and Brain Development.

This study examined the relation between self-representation and brain development in infants and young children. Self-representation was assessed by mirror recognition, personal pronoun use, and pretend play. Structural brain images were obtained from magnetic resonance imaging (MRI). Brain development was assessed by a quantitative measure of maturation of the temporo-parietal junction, temporal pole, medial frontal cortex, and occipital cortex. Fifteen children (15 to 30 months of age; 3 girls) without MRI abnormalities were assessed. Only maturation of the left temporo-parietal junction was related to self-representation after controlling for age. These findings provide some evidence that brain maturation is related to the emergence of a representation of self in the human child.

Finding lung nodules with and without comparative visual scanning

Detection of lung nodules contained in chest X-ray films was studied during both tachistoscopic presentation and free search. Lung nodules were first rated for their visibility against the anatomical background of the chest films. With tachistoscopic presentation, detection accuracy was influenced by rated visibility and by exposure durations up to 180 msec. Eye movements and fixations were recorded during free search. These measures indicated that radiologists use a comparative scanning strategy to differentiate nodules from anatomical structures. The frequency of comparative scans was influenced by rated visibility: Less visible nodules received more comparisons than the more visible nodules. We believe that the radiologist compares suspected nodules with the features of normal structures which serve as references for decisions.

Brain activation when hearing one's own and others' names.

Using functional magnetic resonance imaging, brain activation patterns were examined in response to hearing ones own first name in contrast to hearing the names of others. There are several regions in the left hemisphere that show greater activation to ones own name, including middle frontal cortex, middle and superior temporal cortex, and cuneus. These findings provide evidence that hearing ones own name has unique brain functioning activation specific to ones own name in relation to the names of others.