Biomedical subjects
A W Ellis
Publications and source records attributed to A W Ellis.
More things in heaven and earth than are dreamt of in the initial letter acuity hypothesis.
Schwartz, Montagner, and Kirsner (1987 Brain and Language, 31, 301-307) claim that length X visual hemifield interactions for recognition of horizontal words reflect acuity differences for the initial letters of short and long words rather than different methods of lexical access for words presented in the LVF and in the RVF. They argue that Young and Ellis did not satisfactorily eliminate this possibility because they (Young & Ellis, 1985, Brain and Language, 24, 326-358, Experiment 3) allowed the use of sophisticated guessing strategies. We demonstrate that the presentation conditions of the Schwartz et al. (1987) experiment are different from those of our (Young & Ellis, 1985) experiments in potentially important ways, and that the acuity gradient explanation proposed by Schwartz et al. to account for word length X visual hemifield interactions is inadequate in terms of both the existing literature and a reanalysis of data from our own (Young & Ellis, 1985) Experiments 1 and 3.
Repetition priming of face recognition.
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Matching familiar and unfamiliar faces on identity and expression.
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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.
Access to identity-specific semantic codes from familiar faces.
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Naming and categorizing faces and written names.
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Different methods of lexical access for words presented in the left and right visual hemifields.
Right-handed adults were asked to identify by name bilaterally presented words and pronounceable nonwords. For words in the normal horizontal format, word length (number of letters) affected left visual hemifield (LVF) but not right visual hemifield (RVF) performance in Experiments 1, 2, 3, 5, and 6. This finding was made for words of high and low frequency (Experiment 6) and imageability (Experiment 5). It also held across markedly different levels of overall performance (Experiments 1 and 2), and across different relative positionings of short and long words in the LVF and RVF (Experiment 3). Experiment 4 demonstrated that the variable affecting LVF performance is the number of letters in a word, not its phonological length. For pronounceable nonwords (Experiment 7) and words in unusual formats (Experiment 8), however, length affected both LVF and RVF performance. The characteristics identified for RVF performance in these experiments also hold for the normal reading system. In this (normal) system the absence of length effects for horizontally formatted words is generally taken to reflect the processes involved in lexical access. Length effects in the normal reading system are thought to arise when lexical access for unusually formatted words and for the pronunciation of nonwords requires the short-term storage of information at a graphemic level of analysis. The characteristics of LVF performance indicate that horizontally formatted words presented to the right cerebral hemisphere can only achieve lexical access by a method that requires the short-term storage of graphemic information. This qualitative difference in methods of lexical access applies regardless of whether the right hemisphere is seen as accessing words in the left hemisphere's lexicon or words in a lexicon of its own.
Familiarity decisions for faces presented to the left and right cerebral hemispheres.
Right-handed subjects were asked to decide whether or not faces presented briefly in the RVF or in the LVF were familiar (familiar faces were those of famous people). This task avoids the need for extensive semantic processing or temporary storage involved in conventional naming or identification tasks, and thus eliminates the contribution of such factors to any observed asymmetry. The resulting finding of faster reaction times to LVF faces, with no overall visual hemifield difference in error rates, is taken to indicate a right-hemisphere superiority either in the processes used to construct facial representations or in the accessing of face recognition units, or both.
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.
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.
Wernicke's aphasia and normal language processing: a case study in cognitive neuropsychology.
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Comments on the interpretation of lateral asymmetries in the naming of words and line drawings.
Young, Bion, and Ellis (Brain and Language, 11, 54-65, 1980) found no visual hemifield differences for right-handed subjects' first reports of bilaterally presented picturable nouns and line drawings, and small RVF superiorities for second reports of these stimuli. Levine and Banich (1982), however, found no visual hemifield differences for line drawings, and a substantial RVF superiority for picturable words. Two procedural factors are identified as responsible for this difference in results; namely the lack of control of order of report in Levine and Banich's (1982) study, and their use of vertically aligned words. Levine and Banich's (1982) attempt to explain findings of side of presentation X report interactions in terms of directional scanning and reporting preferences is shown to be untenable. Explanations in terms of cerebral asymmetries are more convincing, but they must be related to explicit theoretical models.
Directional scanning or reporting preferences are not the cause of visual hemifield x report interactions.
Young, Bion and Ellis (1980) and Young and Bion (1981) suggested that findings of visual hemifield x report interactions in the naming of bilaterally presented line drawings reflect cerebral hemisphere differences in ability to effect the temporary storage needed when an identified drawing must be reported second. This interpretation has been questioned on the grounds that such a result could also arise from a preference for left to right over right to left scanning or reporting of stimuli. This directional preference account is shown to be untenable because when subjects fixate to one side of both members of horizontal pairs of drawings there is no sign of the (left or right) drawing position x report interaction that it predicts.
Age of reading acquisition does not affect visual hemifield asymmetries for naming imageable nouns.
Nouns of high imageability and low or high age of reading acquisition were presented bilaterally to adult subjects, who were asked to name them. Order of report of nouns appearing in the LVF and in the RVF was counterbalanced. RVF nouns were more accurately named, regardless of age of reading acquisition. This result is inconsistent with the hypothesis that the right cerebral hemisphere acquires its 'visual vocabulary' during the early stages of learning to read. Despite being matched to high reading age nouns on frequency and imageability, low reading age nouns were more accurately named.
Visual hemifield asymmetry for naming concrete nouns and verbs in children between seven and eleven years of age.
Three letter concrete nouns (Experiment 1) or verbs (Experiment 2) were exposed tachistoscopically in the right and left visual hemifields using a technique of bilateral stimulation with cued order of report. For subjects aged seven to eleven years, both types of word gave a small RVF advantage on words reported first and a larger RVF advantage on words reported second. This interaction between order of report and visual hemifield has been found by Young, Bion and Ellis (1980) to characterize stimuli which the right hemisphere is able to recognize. The absence of age X visual hemifield interactions argues against any progressive lateralisation through childhood, but may be indicative of the way the right hemisphere acquires its reading vocabulary.
Left and wrong in adverts: Neuropsychological correlates of aesthetic preference.
Twenty left-handed and 20 right-handed subjects were found to differ significantly in their preferences for the left-right arrangement of words and pictures in advertisements. The right-handers preferred the picture to the left of the text, while left-handers had no overall preference, but showed a wider range of individual variation. The results are interpreted as demonstrating an influence of hemispheric specialization on everyday aesthetic preferences.
Asymmetry of cerebral hemispheric function in normal and poor readers.
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