The effects of stimulus and subject factors on a face matching task.

An initial experiment revealed that, under very rapid viewing conditions, the usual asymmetry for face recognition occurred only for low-detail facial sketches. Photographs and medium-detail sketches failed to show VF asymmetry. A further experiment revealed that the effect was unlikely to be attributable to discrimination difficulties; this experiment, however, replicated the LVF superiority on low-detail faces only for male subjects. These results are briefly examined in the light of Sergent's theoretical interpretation of hemisphere asymmetry (Sergent, J. Percept. Psychophys. 31, 451-461, 1982). They are also discussed in relation to sex differences in cerebral asymmetry.

Reduced autonomic responses to faces in Capgras delusion.

People experiencing the Capgras delusion claim that others, usually those quite close emotionally, have been replaced by near-identical impostors. Ellis & Young suggested in 1990 that the Capgras delusion results from damage to a neurological system involved in orienting responses to seen faces based on their personal significance. This hypothesis predicts that people suffering the Capgras delusion will be hyporesponsive to familiar faces. We tested this prediction in five people with Capgras delusion. Comparison data were obtained from five middle-aged members of the general public, and a psychiatric control group of five patients taking similar anti-psychotic medication. Capgras delusion patients did not reveal autonomic discrimination between familiar and unfamiliar faces, but orienting responses to auditory tones were normal in magnitude and rate of initial habituation, showing that the hyporesponsiveness is circumscribed.

Re-evaluating age-of-acquisition effects: are they simply cumulative-frequency effects?

The time it takes to read or produce a word is influenced by the word's age of acquisition (AoA) and its frequency (e.g. Quarterly Journal of Experimental Psychology 12 (1973) 85). Lewis (Cognition 71 (1999) B23) suggested that a parsimonious explanation would be that it is the total number of times a word has been encountered that predicts reaction times. Such a cumulative-frequency hypothesis, however, has always been rejected because the statistical effects of AoA and frequency are additive. Here, it is demonstrated mathematically that the cumulative-frequency hypothesis actually predicts such results when applied to curvilinear learning. Further, the data from four influential studies (two of which claim support for independent effects of AoA and frequency) are re-analyzed to reveal that, in fact, they are consistent with a cumulative-frequency hypothesis. The conclusion drawn is that there is no evidence with which to refute the most parsimonious of explanations, i.e. cumulative frequency can account for both frequency and AoA effects.

Recognition of upright and inverted faces presented in the left and right visual fields.

Pictures of upright and inverted faces were unilaterally presented in either the left or right visual field. Subsequent recognition performance was found to be superior for faces falling in the left visual field regardless of orientation. The results are discussed in relation to Yin's (1970) ideas concerning a face-specific recognition system located in the right hemisphere.

Mea culpa? A study of the relationships among personality traits, life-events and ascribed accident causation.

On the basis of their own reports, accident victims attending a casualty department were independently assigned either to a causal group (n = 25), i.e. apparently culpable in causing their accident, or a non-causal group (n = 25). Comparisons were made between these two groups of patients on: (1) sociodemographic characteristics; (2) locus of control; (3) recent life-events; and (4) cognitive failures. The groups differed only in their tendency to perceive locus of control as being internal (causal group) or external (non-causal group).

Covert face recognition without prosopagnosia.

An experiment is reported where subjects were presented with familiar or unfamiliar faces for supraliminal durations or for durations individually assessed as being below the threshold for recognition. Their electrodermal responses to each stimulus were measured and the results showed higher peak amplitude skin conductance responses for familiar than for unfamiliar faces, regardless of whether they had been displayed supraliminally or subliminally. A parallel is drawn between elevated skin conductance responses to subliminal stimuli and findings of covert recognition of familiar faces in prosopagnosic patients, some of whom show increased electrodermal activity (EDA) to previously familiar faces. The supraliminal presentation data also served to replicate similar work by Tranel et al (1985). The results are considered alongside other data indicating the relation between non-conscious, "automatic" aspects of normal visual information processing and abilities which can be found to be preserved without awareness after brain injury.

Reduplication of visual stimuli.

Investigation of P.T., a man who experienced reduplicative delusions, revealed significant impairments on tests of recognition memory for faces and understanding of emotional facial expressions. On formal tests of his recognition abilities, P.T. showed reduplication to familiar faces, buildings, and written names, but not to familiar voices. Reduplication may therefore have been a genuinely visual problem in P.T.'s case, since it was not found to auditory stimuli. This is consistent with hypotheses which propose that the basis of reduplication can lie in part in malfunction of the visual system.

Face processing impairments and delusional misidentification.

We report detailed investigations of the face processing abilities of four patients who had shown symptoms involving delusional misidentification. One (GC) was diagnosed as a Frégoli case, and the other three (SL, GS, and JS) by symptoms of intermetamorphosis. The face processing tasks examined their ability to recognize emotional facial expressions, identify familiar faces, match photographs of unfamiliar faces, and remember photographs of faces of unfamiliar people. The Frégoli patient (GC) was impaired at identifying familiar faces, and severely impaired at matching photographs of unfamiliar people wearing different disguises to undisguised views. Two of the intermetamorphosis patients (SL and GS) also showed impaired face processing abilities, but the third US) performed all tests at a normal level. These findings constrain conceptions of the relation between delusional misidentification, face processing impairment, and brain injury.

Recognizing faces.

Following a review of the stimulus and subject factors which have been found to affect recognition faces, the question of whether this process can be considered a special one is dealt with. Evidence from studies involving the development of face recognition, the recognition of inverted faces, and the clinical condition prosopagnosia is considered, and in each case found to be inadequate for the unequivocal conclusion that the processes underlying face recognition are qualitatively different from those employed in recognizing other pictorial material.

Intra- and inter-modal repetition priming of familiar faces and voices.

Two experiments explored repetition priming for familiar voices and faces. Expt 1 revealed that, like faces, prior exposure to a voice in a gender judgment task speeds its subsequent classification as familiar or unfamiliar, some minutes later. Faces and voices do not prime one another, however; a result consistent with the notion that evidence is initially accumulated separately for voices and faces. In Expt 2, a prediction derived from the IAC model of Burton, Bruce & Johnston (1990) was explored. The results confirmed that inter-modal repetition priming occurs when the interval between exposures to different personal identification stimuli are separated by a short SOA. This result is consistent with similar ones reported by Calder (1993) and Young, Flude, Hellawell & Ellis (1994) for face-name combinations.

Within-race and between-race recognition of transformed and untransformed faces.

Numerous studies have shown that people from one racial group experience difficulties in remembering the faces of people from other racial groups. Two experiments are reported that explore the phenomenon more fully by examining subjects' ability to recognize faces transformed slightly in pose between study and test. Published work shows that white subjects can recognize such transformed white faces as well as they identify untransformed faces. In the first experiment, it was shown that white subjects were unable to recognize transformed black faces. The second experiment, following the pilot study, investigated recognition of both black and white, transformed and untransformed faces by Europeans and Africans. This study revealed that people from one racial group are particularly disadvantaged in recognizing other-race faces that have undergone transformation. The results are discussed in relation to learning approaches to face memory.

Similarity effects in face recognition.

Three experiments are described which examine the effects of similarity on face recognition using a new application of hierarchical clustering analysis (HCS). Experiments I and II employed a within-groups design where subjects attempted to recognize targets among decoys from the same and different cluster to the target. Common cluster membership accounted for 72% and 84%, respectively, of all false alarms in the two experiments. Absolute error rates were affected by the number of targets actually present in the array and the style of the instructions given to subjects but were not influenced by whether successive or simultaneous test presentation was employed. Experiment III used a between-subject design where targets were embedded in arrays composed from same or different clusters. False alarm rates were significantly higher for the same cluster condition, but hit rates were unaffected by recognition context. The significance of these findings for theories of face identification is discussed.

Cold and performance: the effects of information load, analgesics, and the rate of cooling.

In the first experiment, 8 subjects took part in two experimental sessions--one after receiving one of two kinds of analgesic and the other after receiving a placebo. For each session, subjects completed 8- and 4-choice versions of a serial choice reaction time (SCRT) task at three times: before, during, and after exposure in a cold room at -5 degrees C. Body temperatures were monitored throughout and comfort ratings were recorded. The results indicated that cold increased error rate on the SCRT task, particularly for the 8-choice version which was also associated with faster RTs. However, a speed-accuracy tradeoff explanation for the data was discounted on the grounds that, although overall latencies were faster in the cold compared with precold, these were no faster than postcold RTs. The analgesics had no effect on comfort nor did they have an interpretable effect on performance. In experiment 2, where cooling was much slower for 5 subjects, no such increase in error rate on the SCRT task was observed. Similarly slow cooling did not impair general intellectual ability as measured by Raven's Progressive Matrices.

Theory of Mind: Deaf and Hearing Children's Comprehension of Picture Stories and Judgments of Social Situations.

We compared 20 prelingually profoundly deaf adolescents (age: 11-16 years) and 20 matched, hearing adolescents on a picture-sequencing task and on a social judgment test. In addition, we also tested 14 younger deaf children (age: 6-10 years) and compared their data with those from 20 hearing peers as well as those from the older deaf participants on the picture-sequencing task. The results from this study did not provide evidence for the hypothesis that deaf adolescents possess significantly poorer knowledge about social reasoning than age-matched hearing peers, but it did present further additional support for Peterson and Siegal's (1995) conversational hypothesis: a proposal that a deprivation in conversations about mental states leads to an impairment in the development of an awareness of mental states in the younger deaf children.