46 research outputs found
Age Effects in the Processing of Typical and Distinctive Faces
No full text Two experiments exploring the differential processing of distinctive and typical faces by adults and children are reported. Experiment 1 employed a recognition memory task. On three out of four dimensions of measurement, children of 5 years of age did not show an advantage for distinctive faces, whereas older children and adults did. In Experiment 2, however, subjects of all ages classified typical faces faster than distinctive ones in a face/non-face decision task: the 5-year-olds performed exactly as did adults and older children. The different patterns in performance between these two tasks are discussed in relation to possible cognitive architectures for the way young children represent faces in memory. Specifically, we examine two alternative architectures proposed by Ellis (1992) as precursors for Valentine's (1991a) multidimensional adult face-space and discuss whether implementations of these spaces should be based on a norm-based or an exemplar-based framework. </jats:p
The Effects of Cold on the Performance of Serial Choice Reaction Time and Various Discrete Tasks
No full text Two experiments are reported in which subjects performed a number of tasks before, during, and following exposure to cold. The main performance task, involving serial choice reaction times, yielded consistently large increases in error that were attendant upon reductions in mean skin temperature, and appeared largely independent of any fall in rectal temperature. Other more discrete tasks investigated over the two experiments included a simple reaction time test and the Stroop Word Color Test. The results of these tests indicated no significant performance changes in the cold. Performance on a verbal reasoning test, however, was slightly improved in the cold. The results are discussed in terms of an arousal versus distraction hypothesis of cold effects. </jats:p
Beliefs about delusions
No full textEarly in his third month of office, President Reagan was on his way to address a conference when John Hinckley fired six gun shots at point blank range, wounding the president and three of his entourage. In the controversial trial that followed, three defence psychiatrists successfully argued that Hinckley was not guilty, on the grounds that he was suffering from the delusion that the assassination would cause Jodie Foster, the actress from Taxi Driver (a film which Hinckley was obsessed with), to fall in love with him. In the same year the award-winning author Philip K. Dick, whose books have been turned into major Hollywood films, such as Blade Runner, Total Recall and Minority Report, published one of his last books. The sprawling and eccentric VALIS is a novel based on delusions resulting from his own psychotic breakdown, which he drew on for much of his prolific career (see box). From these and many other examples, it would appear that unusual or unlikely beliefs have significant consequences and continue to captivate the interest of many of us. But to examine such claims we need to know what is meant by a delusion. How do delusions differ from other abnormal beliefs? Does the study of delusions provide a productive way of understanding beliefs
Autonomic responses to familiar faces without autonomic responses to familiar voices: Evidence for voice-specific Capgras delusion
No full textIntroduction: Patients with Capgras delusion believe that certain individuals have been replaced by duplicates. Unlike normal people, these patients also show reduced autonomic responses to familiar faces, indicating the possibility that it is the covert processes of recognition that are impaired (Ellis, et al., 1997). It has been suggested that such patients would show normal autonomic responses to voices. An auditory parallel of this typical delusion, therefore, is theoretically possible. That is, a delusion whereby mis-recognition of the voice produces the delusional belief of duplication. Such a delusion would only occur in situations where the person is recognised by voice only; and so, even where it does exist, it would often escape diagnosis. Method: We present here a case, H.L., of what appears to be the Capgras delusion for voices in a sighted person. This case was investigated using standard skin conductance tests for face and voice recognition. Results: Consistent with this diagnosis, H.L. displays normal autonomic responses for faces but reduced autonomic responses for famous voices. Discussion: H.L. represents a previously unreported form of Capgras delusion and, further, shows dissociation between autonomic responses to faces and voices. Implications for cognitive models of person recognition are discussed
