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Biomedical subjects

Katherine A Leighty

Publications and source records attributed to Katherine A Leighty.

5 recordsLinked to original sources
PubMed2006

The path of visual attention.

Visual cuing is one paradigm often used to study object- and space-based visual selective attention. A primary finding is that shifts of attention within an object can be accomplished faster than equidistant shifts between objects. The present study used a visual cuing paradigm to examine how an object's size (i.e., internal distance) and shape, influences object- and space-based visual selective attention. The first two experiments manipulated object size and compared attentional shift performance with objects where the within-object distance between cued and uncued target locations was either equal to the between-object distance (1:1 ratio condition) or three times the between-object distance (3:1 ratio condition). Within-object shifts took longer for the larger objects, but an advantage over between-object shifts was still evident. Influences associated with the shapes of the larger objects suggested by the results of the first two experiments were tested and rejected in Experiment 3. Overall, the results indicate that within-object shifts of attention become slower as the within-object distance increases, but nevertheless are still accomplished faster than between-object shifts.

Analysis of Variance↗
PubMed2005

Are monkeys aesthetists? Rensch (1957) revisited.

Three experiments assessed whether capuchin monkeys (Cebus apella) and squirrel monkeys (Saimiri sciureus) prefer regular and symmetrical visual patterns. Pictorial representations of faces were included in 1 stimulus set. When the monkeys could pick up and manipulate small cards bearing the stimuli, all preferences expressed by capuchins and most of those expressed by squirrel monkeys were for regular stimuli. Symmetry of the patterns was influential but not essential. Some preferences were also found for faces. When images of the patterns were presented on a touch screen, capuchins continued to express preferences especially for regular and symmetrical stimuli, but they showed some avoidance of faces. Squirrel monkeys responded less discriminatingly to the touch screen stimuli. The findings provide support for B. Rensch's (1957) claim that monkeys prefer visual stimuli that humans find aesthetically pleasing.

Animals↗
PubMed2003

Joystick acquisition in tufted capuchins (Cebus apella).

A number of nonhuman primate species have demonstrated the ability to use a joystick to control a cursor on a computer screen, yet the acquisition of this skill has not been the focus of systematic inquiry. Here, we examined joystick acquisition in four tufted capuchins under two directional relationships of joystick movement and resultant cursor displacement, isomorphic and inverted. To document the natural history of the acquisition of this skill, we recorded the development of visual tracking of the cursor and body tilting. Rates of acquisition were comparable between the two conditions. After mastering the task in one condition, subjects remastered the task at an accelerated rate in the opposing condition. All subjects significantly increased or maintained high proportions of cursor tracking throughout acquisition. All subjects demonstrated a postural tilt while moving the cursor from the mid-phase of acquisition through task mastery. In the isomorphic condition, all subjects tilted significantly more often in the direction of goal location than in the opposite direction. In three of the four series of tilting that were scored for subjects in the inverted condition, tilting occurred significantly more often toward the direction of goal location than the direction of required hand movement. Together these findings suggest that body tilting participates in the organization of directional movement of the cursor rather than reflecting merely the motoric requirements of the task (to manipulate a joystick).

Animals↗
PubMedDate not supplied

Twinning in tufted capuchins (Cebus apella): rate, survivorship, and weight gain.

We calculated the rate of twinning across four captive collections of tufted capuchins (Cebus apella) to be 2.4%. This rate contrast with previous reports that twinning in tufted capuchins is rare. Additionally, we present data on the survival and weight gain of twins in this species as compared to singletons. Twins face their greatest risk of mortality on or before the first day of life, when 45% will die compared to 16% of singletons. After the first day of life, twins and singletons demonstrate comparable survival rates. This, in conjunction with the finding that at no time during the first year of life do twins and singletons differ significantly in their weights, suggests that twinning is a viable reproductive form for these animals, especially in the captive setting where nutritional demands are met.

Animals↗