Biomedical subjects

Gudrun Schwarzer

Publications and source records attributed to Gudrun Schwarzer.

4 recordsLinked to original sources

PubMed2006

Gaze behaviour in hereditary prosopagnosia.

Prosopagnosia is the inability to recognize someone by the face alone in the absence of sensory or intellectual impairment. In contrast to the acquired form of prosopagnosia we studied the congenital form. Since we could recently show that this form is inherited as a simple monogenic trait we called it hereditary form. To determine whether not only face recognition and neuronal processing but also the perceptual acquisition of facial information is specific to prosopagnosia, we studied the gaze behaviour of four hereditary prosopagnosics in comparison to matched control subjects. This rarely studied form of prosopagnosia ensures that deficits are limited to face recognition. Whereas the control participants focused their gaze on the central facial features, the hereditary prosopagnosics showed a significantly different gaze behaviour. They had a more dispersed gaze and also fixated external facial features. Thus, the face recognition impairment of the hereditary prosopagnosics is reflected in their gaze behaviour.

Adult↗

PubMed2005

Gaze behavior in analytical and holistic face processing.

We conducted two experiments examining children's and adults' gaze behavior when processing faces analytically (focusing on a single feature) or holistically (comparing the overall similarity of the faces). Children 6-8 and 9-10 years of age and adults were instructed to assign schematically drawn faces in Experiment 1 and photos of real faces in Experiment 2 to two categories. The categories were constructed so as to allow either an analytical or holistic categorization of the faces. During all trials, gaze behavior was recorded from stimulus onset until reaction. The location and duration of the fixations used were analyzed. Whereas the holistic processors fixated the whole area of the eyes and nose most and longest independently of age, analytical processors showed a more feature-specific gaze behavior, focusing their fixations upon the particular feature used for subsequent processing. Thus, differences in analytical and holistic face processing can be detected early in gaze behavior-that is, at the visual encoding stage.

Adolescent↗

PubMed2003

Face processing in 8-month-old infants: evidence for configural and analytical processing.

Two experiments examined whether 8-month-old infants process faces (photos in Experiment 1, schematic faces in Experiment 2) analytically by processing facial features independently of the facial context or configurally by processing the features in conjunction with the facial context. Infants were habituated to two faces and looking time was measured. After habituation they were tested with a habituation face, a switch face, or a novel face. In the switch faces, single features of the habituation faces were switched. The results showed that the infants processed facial features of photographs of faces configurally whereas they processed features of schematic faces (eyes, nose, facial contour) analytically. Thus, although infants have access to both processing modes, for real looking faces they use the configural mode.

Discrimination, Psychological↗

PubMed2002

Children's face recognition in different contexts: the role of encoding strategies.

In this study, the relationship between face recognition and different facial encoding strategies was investigated. Children (6-8 years, N= 134) participated in both a face recognition task and an encoding task. During the recognition task, they saw 7 target faces in an eyewitness context (video) or in a neutral context (static black and white slides) which they later had to recognize from a set of 21 faces. On the encoding task, the same children had to categorize new faces (schematic and photorealistic) into two categories. The construction of the categories allowed participants to encode the faces either analytically (by focusing on a single attribute) or holistically (in terms of overall similarity). The results showed that face recognition was better in the social than in the neutral context. In the neutral context, only holistic encoding was connected to better face recognition. In the social context, children seemed to use not only information about the faces but also information about the persons.

Affect↗