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Biomedical subjects

D C Hay

Publications and source records attributed to D C Hay.

14 recordsLinked to original sources
PubMed1992

Face processing in psychiatric conditions.

Functional models of face processing have indicated that dissociations exist between the various processes involved, e.g. between familiar face recognition and matching of unfamiliar faces, and between familiar face recognition and facial expression analysis. These models have been successfully applied to the understanding of the different types of impairment that can exist in neuropsychological patients. In the present study, aspects of face processing in psychiatric patients were investigated in relation to Bruce & Young's (1986) model. Based on this functional model different predictions can be made. We contrast here the impaired expression analysis hypothesis, which is that psychiatric patients would show a deficit in facial expression recognition, but not in facial identity recognition or unfamiliar face matching, with the generalized deficit hypothesis, that patients would be impaired on all tasks. These hypotheses were examined using three forced-choice tasks (facial recognition, facial expression recognition, and unfamiliar face matching) which were presented to schizophrenic and depressed patients, and to non-patient controls. Results showed that schizophrenic patients performed at a significantly lower level than non-patient controls on all three tasks, supporting the generalized deficit hypothesis.

Adult↗
PubMed1991

Routes through the face recognition system.

Two experiments are reported which seek to examine the proposition first put forward by Hay and Young (1982), that recognition of a known person after seeing his or her face proceeds through a series of sequentially organized stages. In both experiments subjects were shown a selection of famous and unfamiliar faces and required to state whether each face was familiar. They were then asked to recall semantic information and the person's name. Of all the possible response types, only some are predicted by models derived from Hay and Young (1982), and only these responses were observed in Experiment 1. In order to give as complete an account as possible of the slips and errors made by subjects, they were interrogated some days after completing the testing phase in Experiment 2. As in the first experiment, the results supported the view that distinct but successive stages are involved in everyday face recognition. The method developed here provides an extension of the "dairy" type of study of everyday recognition errors into laboratory conditions, which confirms the findings of studies of everyday errors and provides strong support for sequential models.

Adult↗
PubMed1990

Facial neglect.

Following a stroke, a retired industrial chemist, K.L., complained that faces looked "different" and had become difficult to recognize. Investigation of this problem revealed that it particularly affected the left half of a face as seen by K.L. Defective recognition of this (left) half was found for normal faces, chimaeric faces, and for half-faces presented in isolation, whether upright or inverted. The problem was apparent for both internal and external facial features. Further studies with chimaeric faces demonstrated inattention to left-side features in K.L.'s judgements of facial expression and of resemblance between faces. Moreover, the left-half of a chimaeric face was affected even when it was itself forming part of the face positioned on the right in a display of two horizontally aligned chimaerics. K.L.'s spatial contrast sensitivity function was within normal limits for his age. He did not experience differential difficulty in recognizing the left side of everyday objects or of car-fronts (another stimulus class demanding within-category discrimination between visually similar items that display approximate left-right symmetry). He was also able to sort left or right half-stimuli correctly into the categories "human face", "dog face", or "tree". Although K.L. had a left visual field defect, the problem with faces occurred within otherwise intact parts of his field of vision. We suggest that his disorder can be considered a domain-specific form of unilateral neglect.

Aged↗
PubMed1987

Configurational information in face perception.

A new facial composites technique is demonstrated, in which photographs of the top and bottom halves of different familiar faces fuse to form unfamiliar faces when aligned with each other. The perception of a novel configuration in such composite stimuli is sufficiently convincing to interfere with identification of the constituent parts (experiment 1), but this effect disappears when stimuli are inverted (experiment 2). Difficulty in identifying the parts of upright composites is found even for stimuli made from parts of unfamiliar faces that have only ever been encountered as face fragments (experiment 3). An equivalent effect is found for composites made from internal and external facial features of well-known people (experiment 4). These findings demonstrate the importance of configurational information in face perception, and that configurations are only properly perceived in upright faces.

Adult↗
PubMed1986

Face-name interference.

Interference effects between the processing of simultaneously presented photographs of faces of familiar people and printed names of familiar people were investigated. Printed names interfered with identifying faces, whereas faces did not interfere with saying printed names (Experiments 1 and 3). In contrast, faces interfered more with name categorization than names interfered with face categorization (Experiments 2 and 4). Despite a priori reasons as to why faces might be thought to possess functional properties different from those of other visual objects, the observed effects are comparable to those found in object-word interference studies, with photographs of faces behaving like pictures of objects and printed people's names behaving like printed names of objects. In face naming tasks, the presence of related names produced more interference than did the presence of unrelated names (Experiment 1). This effect was examined in greater detail in Experiment 3, where we found that the effect arises when the face and the name belong to people of similar appearance. An effect of common category membership was not found in Experiment 3. Experiment 5, however, showed that names of people highly associated with the person whose face is presented also produce more interference than do names of unrelated people.

Association↗
PubMed1985

Right cerebral hemisphere superiority for constructing facial representations.

Right-handed people were asked to decide whether or not stimuli presented in the left visual hemifield (LVF) or in the right visual hemifield (RVF) were faces. Manual reaction times and error rates were recorded under three conditions. In Condition A, stimuli were line drawings of faces and moderately scrambled nonfaces made by rearranging the facial features. In Condition B, stimuli were line drawings of faces and highly scrambled nonfaces. In Condition C, stimuli were line drawings of faces and objects. The results show that faces are identified more quickly from the LVF than from the RVF in Condition A (faces vs moderately scrambled nonfaces), with no visual hemifield difference in reaction times to Condition B (faces vs highly scrambled nonfaces) and Condition C (faces vs objects). These findings are taken to indicate that both cerebral hemispheres are able to assign stimuli to the "face" category, but the right hemisphere is better than the left hemisphere at constructing facial representations. This cerebral hemisphere difference in ability to construct facial representations becomes evident when a detailed representation is required (as in Condition A).

Cerebral Cortex↗
PubMed1985

Matching familiar and unfamiliar faces on internal and external features.

Two experiments are reported in which subjects were asked to match a photograph of a complete face and a simultaneously presented photograph of internal or external features of a face, deciding whether or not the two photographs were pictures of the same person. In experiment 1 'same' pairs were derived from different pictures of the same face, so that subjects had to match the faces and not the particular photographs used. Matches based on internal features were found to be faster for familiar than for unfamiliar faces, whereas there was no difference in reaction time between matches based on the external features of familiar and unfamiliar faces. Faster matching of internal features of familiar faces was found to hold equally for pairs of photographs that differed in orientation of the face or in facial expression. In experiment 2 'same' pairs were derived from the same photographs, which gave subjects the choice of matching on the basis of the features of the depicted faces or matching the photographs. Reaction times were faster than in experiment 1, and there were no differences between familiar and unfamiliar faces. The study confirms reports of differential saliency of the internal features of familiar faces, and shows that this only holds when stimuli are treated as faces. The finding thus reflects properties of structural rather than pictorial codes.

Face↗
PubMed1985

The faces that launched a thousand slips: everyday difficulties and errors in recognizing people.

Twenty-two people kept records of difficulties and errors they experienced in recognizing people, producing a main set of 922 records of difficulties and errors collected over a seven-week period, and a subsidiary set of 86 records of experiences in which an encountered person was noticed to resemble a known person in some way(s). These records are classified into different types, and used to develop a model of person recognition in which representational systems create structural descriptions of the encountered person that are submitted to checks for resemblances to known people (by recognition units); any such resemblances can then be used to access person identity information (held in person identity nodes), and then additional information (including the appropriate name) held in separate stores. Outputs from the recognition units and from the person identity nodes go to the rest of the cognitive system, which can be important in taking decisions as to the 'real' identity of an encountered person, and which also has at its disposal various ways of gaining further information that may assist such decisions.

Discrimination Learning↗