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Biomedical subjects

T Valentine

Publications and source records attributed to T Valentine.

At least 19 recordsLinked to original sources

Face recognition and emotional valence: processing without awareness by neurologically intact participants does not simulate covert recognition in prosopagnosia.

Covert face recognition in neurologically intact participants was investigated with the use of very brief stimulus presentation to prevent awareness of the stimulus. In Experiment 1, skin conductance response (SCR) to photographs of celebrity and unfamiliar faces was recorded; the faces were displayed for 220 msec and for 17 msec in a within-participants design. SCR to faces presented for 220 msec was larger and more likely to occur with familiar faces than with unfamiliar faces. Face familiarity did not affect the SCR to faces presented for 17 msec. SCR was larger for faces of good than for faces of evil celebrities presented for 17 msec, but valence did not affect SCR to faces displayed for 220 msec. In Experiment 2, associative priming was found in a face familiarity decision task when the prime face was displayed for 220 msec, but no facilitation occurred when primes were presented for 17 msec. In Experiment 3, participants were able to differentiate evil and good faces presented without awareness in a two-alternative forced-choice decision. The results provide no evidence of familiarity detection outside awareness in normal participants and suggest that, contrary to previous research, very brief presentation to neurologically intact participants is not a useful model for the types of covert recognition found in prosopagnosia. However, a response based on affective valence appears to be available from brief presentation.

Adolescent↗

Proper-name processing: are proper names pure referencing expressions?

Theoretical models of proper-name processing have been primarily derived from studies of people's names; however, they are thought to generalize to all classes of proper name. Five experiments are reported that use repetition priming to compare different classes of proper names. It was found that for people's names and landmark names, (a) production of a name in response to seeing a picture primed a subsequent familiarity decision to the same item's written name and (b) similarly, making a familiarity decision to an auditory presentation of a name primed a familiarity decision to the same item's written name. No comparable facilitation was found for the country-name stimuli. The presence of this specific facilitation was attributed to the nature of connectivity between conceptual and lexical representations. Theoretical views that proper names are unique, meaningless labels and that they are pure referencing expressions are evaluated.

Adult↗

The development of competency standards for specialist critical care nurses.

In defining the contemporary role of the specialist nurse it is necessary to challenge the concept of nursing as merely a combination of skills and knowledge. Nursing must be demonstrated and defined in the context of client care and include the broader notions of professional development and competence. This qualitative study sought to identify the competency standards for nurse specialists in critical care and to articulate the differences between entry-to-practice standards and the advanced practice of specialist nurses. Over 800 hours of specialist critical care nursing practice were observed and grouped into 'domains' or major themes of specialist practice using a constant comparison qualitative technique. These domains were further refined to describe attributes of the registered nurses which resulted in effective and/or superior performance (competency standards) and to provide examples of performance (performance criteria) which met the defined standard. Constant comparison of the emerging domains, competency standards and performance criteria to observations of specialist critical care practice, ensured the results provided a true reflection of the specialist nursing role. Data analysis resulted in 20 competency standards grouped into six domains: professional practice, reflective practice, enabling, clinical problem solving, teamwork, and leadership. Each of these domains is comprised of between two and seven competency standards. Each standard is further divided into component parts or 'elements' and the elements are illustrated with performance criteria. The competency standards are currently being used in several Australian critical care educational programmes and are the foundation for an emerging critical care credentialling process. They have been viewed with interest by a variety of non-critical care specialty groups and may form a common precursor from which further specialist nursing practice assessment will evolve.

Australia↗

Age-of-acquisition and cumulative frequency have independent effects.

Lewis (1999) argued that effects of age of acquisition (AoA) are entirely attributable to cumulative frequency. He reported an instance-based model in which the number of instances of the stimulus stored in memory predicts reaction time. We note four aspects of the literature on AoA that cannot be explained by this instance-based approach. Firstly, an effect of AoA has been observed in the absence of an effect of frequency. Secondly, an effect of AoA has been observed when cumulative frequency has been controlled. Thirdly, the effect of AoA is dependent on task. Fourthly, the effect of word frequency is dependent on stimulus modality. Lewis reported an experiment in which participants make a decision based on identity-specific semantic information to celebrity faces to demonstrate an effect of the number of instances in memory, which he interpreted as an effect of AoA. We note that effects of AoA have been found in lexical and perceptual tasks, but to date all attempts to demonstrate an advantage for early-acquired items in semantic classification tasks have failed. We conclude that the effects of AoA cannot be attributed solely to the effects of cumulative frequency.

Age Factors↗

Recognizing unfamiliar faces: the effects of distinctiveness and view.

Three experiments are reported in which the effects of viewpoint on the recognition of distinctive and typical faces were explored. Specifically, we investigated whether generalization across views would be better for distinctive faces than for typical faces. In Experiment 1 the time to match different views of the same typical faces and the same distinctive faces was dependent on the difference between the views shown. In contrast, the accuracy and latency of correct responses on trials in which two different faces were presented were independent of viewpoint if the faces were distinctive but were view-dependent if the faces were typical. In Experiment 2 we tested participants' recognition memory for unfamiliar faces that had been studied at a single three-quarter view. Participants were presented with all face views during test. Finally, in Experiment 3, participants' were tested on their recognition of unfamiliar faces that had been studied at all views. In both Experiments 2 and 3 we found an effect of distinctiveness and viewpoint but no interaction between these factors. The results are discussed in terms of a model of face representation based on an inter-item similarity in which the representations are view specific.

Adult↗

The effect of age of acquisition on speed and accuracy of naming famous faces.

Three experiments examined whether famous faces would be affected by the age at which knowledge of the face was first acquired (AoA). Using a multiple regression design, Experiment 1 showed that rated familiarity and AoA were significant predictors of the time required to name pictures of celebrities' faces and the accuracy of producing their names. Experiment 2 replicated an effect of AoA using a factorial design in which other attributes of the celebrities were matched. In both Experiments 1 and 2, several ratings had been collected from participants before naming latency data were collected. Experiment 3 investigated the accuracy and latency of naming celebrities without any prior exposure to the stimuli. An advantage for naming early acquired celebrities was observed even on the first presentation. The participants named the same celebrities in three subsequent presentations of the stimuli. The effect of AoA was not significant on the fourth presentation. The implications of these results for models of face naming and directions for future research are discussed.

Adolescent↗

Descriptiveness and proper name retrieval.

Cohen (1990) hypothesised that the retrieval of proper names is particularly difficult because proper names convey little information about their bearers' attributes. In the present study, this hypothesis was evaluated by using a face naming task. Faces were those of cartoon and comic-strip characters bearing either arbitrary names or descriptive names. Results unequivocally showed that retrieval blocks occurred more often in naming characters bearing arbitrary names than in naming characters bearing descriptive names. Moreover, retrieving arbitrary names that were also common names was as difficult as retrieving arbitrary names that were not common names. These results support Cohen's claim that arbitrariness plays a significant role in the relative vulnerability of proper name retrieval.

Adult↗

Contrasting effects of age of acquisition and word frequency on auditory and visual lexical decision.

In four experiments, we examined the effects of frequency and age of acquisition on auditory and visual lexical decision. Word frequency affected visual, but not auditory, lexical decision speed (Experiments 1 and 3). Age of acquisition affected lexical decision speed in both modalities (Experiments 2 and 4). We suggest that previous reports of effects of frequency on auditory lexical decision may be due to a confounding of frequency with age of acquisition, and we discuss the implications of these findings for theories of auditory and visual word recognition.

Adult↗

On the relationship between reading, listening and speaking: it's different for people's names.

Two experiments are reported that tested predictions derived from the framework of face, object, and word recognition proposed by Valentine, Brennen, and Brédart (1996). The findings were as follows: (1) Production of a celebrity's name in response to seeing the celebrity's face primed a subsequent familiarity decision to the celebrity's printed name. The degree of repetition priming observed was as great as that observed when a familiarity decision to the printed name was repeated in the prime and test phases of the experiment. (2) Making a familiarity decision to an auditory presentation of a celebrity's name primed a familiarity decision to the same celebrity's name presented visually. The magnitude of cross-modality priming was as great as the magnitude of within-modality repetition priming. This result for people's names contrasted with the effects observed in lexical decision tasks, in which no reliable cross-modality priming was observed. The results cannot be accounted for by previous models of face and name processing. They show a marked contrast between processing people's names and processing words. The results support the framework proposed by Valentine et al. (1996). The implications for models of speech production, perception, and reading are discussed, together with the potential of the methodology to elucidate our understanding of proper name processing.

Analysis of Variance↗

An interactive activation model of face naming.

Burton and Bruce's (1992) model of face naming predicts a "fan effect", in which naming of famous people about whom many descriptive properties are known should be slower than naming of celebrities about whom few properties are known. An experiment is reported that showed that, contrary to this prediction, knowledge of many descriptive properties facilitated face-naming latency. An alternative architecture for an interactive activation model is proposed in which descriptive properties are represented in separate pools of units for each domain of information and in which names are represented by a separate pool of lexical output units. Computer simulations showed that this model could simulate the previously available empirical data as effectively as Burton and Bruce's (1992) original model. However, the proposed model could also simulate the effect of the number of known descriptive properties upon face-naming latency observed in the experiment reported. The new architecture also has the advantage of being more compatible with current models of speech production, and it allows preserved access to unique semantic properties in the context of impaired face naming as reported in the neuropsychological literature.

Adult↗

Evidence of covert recognition in a prosopagnosic patient.

This is a case-study of a patient (ET) who suffers from prosopagnosia, in the context of impairment to cognitive functions, following traumatic brain injury. Despite severe perceptual difficulties in tests involving non-face stimuli and matching unfamiliar faces, ET showed evidence of "covert" recognition of familiar faces in a number of tasks. Although densely prosopagnosic, she performed at normal levels in word and object recognition tasks, and is unimpaired in her ability to recognise names of celebrities. She performed at the same level as controls in her ability to make a forced-choice of the correct name for a famous face, even though it evoked no feeling of familiarity for her. She performed at chance in a forced-choice face familiarity decision task, but showed evidence of covert recognition in a "true" versus "untrue" face-name learning task. ET showed overt recognition of some famous faces using a procedure based on Sergent and Poncet's (1990) semantic activation task. The pattern of impairment of ET's face processing abilities is interpreted in terms of an interactive activation model of face processing.

Adult↗

Repetition priming and proper name processing. Do common names and proper names prime each other?

Three experiments are reported in which a repetition priming technique was used to investigate whether recognition of a person's surname which is also a known word (e.g. Baker) activates the lexical representation that mediates word recognition. Experiment 1 showed that a familiarity decision to familiar full names produced an effect of repetition priming on subsequent lexical decision to words that were presented in the initial task as surnames. Experiment 2 demonstrated that, conversely, a lexical decision primed subsequent familiarity decision to full names involving the same word. Experiment 3 showed that repeating the same decision during the initial and test phases did not produce a larger repetition priming effect than that obtained when the task at test differed from the prime task (name familiarity decision vs lexical decision or vice versa). The results are interpreted as support for the view that repetition priming is due to repeated activation of representations that are accessed by both common names and proper names.

Adult↗

From Monroe to Moreau: an analysis of face naming errors.

Functional models of face recognition and speech production have developed separately. However, naming a familiar face is, of course, an act of speech production. In this paper we propose a revision of Bruce and Young's (1986) model of face processing, which incorporates two features of Levelt's (1989) model of speech production. In particular, the proposed model includes two stages of lexical access for names and monitoring of face naming based on a "perceptual loop". Two predictions were derived from the perceptual loop hypothesis of speech monitoring: (1) naming errors in which a (correct) rare surname is erroneously replaced by a common surname should occur more frequently than the reverse substitution (the error asymmetry effect); (2) naming errors in which a common surname is articulated are more likely to be repaired than errors which result in articulation of a rare surname (the error-repairing effect). Both predictions were supported by an analysis of face naming errors in a laboratory face naming task. In a further experiment we considered the possibility that the effects of surname frequency observed in face naming errors could be explained by the frequency sensitivity of lexical access in speech production. However, no effect of the frequency of the surname of the faces used in the previous experiment was found on face naming latencies. Therefore, it is concluded that the perceptual loop hypothesis provides the more parsimonious account of the entire pattern of the results.

Adult↗

Linear and nonlinear effects of aging on categorizing and naming faces.

Subjects aged 54-84 performed 5 separate tasks involving various aspects of face processing: structural decisions (1), familiarity decisions (2), semantic decisions (3), first-name decisions (4), and name retrieval (5). For the categorization tasks (1-4), the mean reaction times for the older subjects (over 65) were plotted against the corresponding means for the younger subjects (under 65). This produced a linear function (slope greater than 1, intercept less than 0), providing only partial support for a simple, multiplicative model of cognitive slowing with age. Reaction time distributions were also plotted for each of the 5 tasks (older vs. younger subjects). The resulting functions were almost perfectly linear, with the exception of name retrieval, which was exponential with respect to age. This was attributed to the increased probability of a tip-of-the-tongue state with age caused by insufficient activation at the level of the name information (the final state of face identification).

Aged↗

Towards an exemplar model of face processing: the effects of race and distinctiveness.

Valentine (1991a, 1991b) described a theoretical framework for face recognition in which faces are encoded as locations in a multidimensional space. It was argued that this approach could provide a unified account of the effects of distinctiveness, inversion, and race on face recognition. In this paper we evaluate the ability of this theoretical framework to account for the effects of distinctiveness and race in four experiments in which white British and Japanese faces served as stimuli and both white British and Japanese students acted as subjects. In a recognition memory experiment the expected "own-race bias" was observed as a Race of Subject x Race of Face interaction. Distinctive faces were recognized more accurately than typical faces, but the effect of distinctiveness did not interact with the race of face or the race of subject. Typical faces were classified faster than distinctive faces in a task in which intact faces had to be distinguished from jumbled faces, as found in earlier work, and the effect of distinctiveness did not interact with the race of face or race of subject. In contrast, a task in which subjects classified faces according to their race did show a greater effect of distinctiveness for own-race faces. The results are discussed in relation to the two specific models within the multidimensional space framework identified by Valentine (1991a): a purely exemplar-based model and a norm-based coding model. It is argued that these results are more easily accommodated in terms of a purely exemplar-based model. Some conceptual problems in applying the norm-based coding model to the effect of race are discussed.

Adult↗

A unified account of the effects of distinctiveness, inversion, and race in face recognition.

A framework is outlined in which individual faces are assumed to be encoded as a point in a multidimensional space, defined by dimensions that serve to discriminate faces. It is proposed that such a framework can account for the effects of distinctiveness, inversion, and race on recognition of faces. Two specific models within this framework are identified: a norm-based coding model, in which faces are encoded as vectors from a population norm or prototype, and a purely exemplar-based model. Both models make similar predictions, albeit in different ways, concerning the interactions between the effects of distinctiveness, inversion and race. These predictions were supported in five experiments in which photographs of faces served as stimuli. The norm-based coding version and the exemplar-based version of the framework cannot be distinguished on the basis of the experiments reported, but it is argued that a multidimensional space provides a useful heuristic framework to investigate recognition of faces. Finally, the relationship between the specific models is considered and an implementation in terms of parallel distributed processing is briefly discussed.

Adult↗

C-type virus particles in placentas of rhesus monkeys after maternal treatment with recombinant leukocyte A interferon.

Interferon inhibits the normal replication of C-type virus particles grown in vitro. The ability of interferon to produce a similar effect in vivo was tested in rhesus monkey placentas which are known to contain C-type virus particles. Samples of placenta from 6 monkeys treated with recombinant leukocyte A interferon (25 x 10(6) units/kg) for 7 to 21 days and from 6 control monkeys were examined in the electron microscope. Budding and immature C-type virus particles were present in every placenta examined from both interferon-treated and control monkeys. Mature particles were found in placentas from 3 of 6 monkeys in both treated and control groups. Possible explanations for the absence of detectable effects of interferon in C-type virus particle formation in these placentas are unresponsiveness of the trophoblast to interferon or inadequate exposure time to interferon of placental sites from which C-type particles are produced.

Animals↗