Biomedical subjects

Karen Lander

Publications and source records attributed to Karen Lander.

4 recordsLinked to original sources

PubMed2006

Recognizing face identity from natural and morphed smiles.

It is easier to identify a degraded familiar face when it is shown moving (smiling, talking; nonrigid motion), than when it is displayed as a static image (Knight & Johnston, 1997; Lander, Christie, & Bruce, 1999). Here we explore the theoretical underpinnings of the moving face recognition advantage. In Experiment 1 we show that the identification of personally familiar faces when shown naturally smiling is significantly better than when the person is shown artificially smiling (morphed motion), as a single static neutral image or as a single static smiling image. In Experiment 2 we demonstrate that speeding up the motion significantly impairs the recognition of identity from natural smiles, but has little effect on morphed smiles. We conclude that the recognition advantage for face motion does not reflect a general benefit for motion, but suggests that, for familiar faces, information about their characteristic motion is stored in memory.

Analysis of Variance↗

PubMed2004

Exploring the role of motion in prosopagnosia: recognizing, learning and matching faces.

HJA has been completely unable to recognize faces since suffering a stroke some 22 years ago. Previous research has shown that he is poor at judging expressions from static photographs of faces, but performs relatively normally at these judgements when presented with moving point-light patterns (Humphreys et al., 1993). Recent research with non-prosopagnosic participants has suggested a beneficial role for facial motion when recognizing familiar faces and learning new faces. Three experiments are reported that investigate the role of face motion for HJA when recognizing (Experiment 1), learning (Experiment 2) and matching faces (Experiment 3). The results indicate that HJA is unable to use face motion to explicitly recognize faces and is no better at learning names for moving faces than static ones. However, HJA is significantly better at matching moving faces for identity, an opposite pattern to that found with age-matched and undergraduate control participants. We suggest that HJA is not impaired at processing motion information but remains unable to use motion as a cue to identity.

Adolescent↗

PubMed2004

Repetition priming from moving faces.

Recent experiments have suggested that seeing a familiar face move provides additional dynamic information to the viewer, useful in the recognition of identity. In four experiments, repetition priming was used to investigate whether dynamic information is intrinsic to the underlying face representations. The results suggest that a moving image primes more effectively than a static image, even when the same static image is shown in the prime and the test phases (Experiment 1). Furthermore, when moving images are presented in the test phase (Experiment 2), there is an advantage for moving prime images. The most priming advantage is found with naturally moving faces, rather than with those shown in slow motion (Experiment 3). Finally, showing the same moving sequence at prime and test produced more priming than that found when different moving sequences were shown (Experiment 4). The results suggest that dynamic information is intrinsic to the face representations and that there is an advantage to viewing the same moving sequence at prime and test.

Face↗

PubMed2003

"Putting the face to the voice": matching identity across modality.

Speech perception provides compelling examples of a strong link between auditory and visual modalities. This link originates in the mechanics of speech production, which, in shaping the vocal tract, determine the movement of the face as well as the sound of the voice. In this paper, we present evidence that equivalent information about identity is available cross-modally from both the face and voice. Using a delayed matching to sample task, XAB, we show that people can match the video of an unfamiliar face, X, to an unfamiliar voice, A or B, and vice versa, but only when stimuli are moving and are played forward. The critical role of time-varying information is underlined by the ability to match faces to voices containing only the coarse spatial and temporal information provided by sine wave speech [5]. The effect of varying sentence content across modalities was small, showing that identity-specific information is not closely tied to particular utterances. We conclude that the physical constraints linking faces to voices result in bimodally available dynamic information, not only about what is being said, but also about who is saying it.

Adult↗