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Biomedical subjects

S W Kelly

Publications and source records attributed to S W Kelly.

16 recordsLinked to original sources
PubMed2001

Learning complex sequences: no role for observation?

Two experiments examined performance in a sequence learning task. Participants were trained on a repeating sequence which was presented as a visual display and learning was measured via the increase in reaction time to respond to a new sequence. Some participants made a response to each stimulus while others merely observed the sequence. In Experiment 1 participants responding to the display via a keypress showed learning, but those merely observing did not. Five possible reasons for the failure to find observational learning were considered and the Experiment 2 attempted to resolve these. This second experiment confirmed the findings of Experiment 1 in a non-spatial sequence display using a cover story which encouraged attention to the display but not rule-search strategies. The results are discussed in relation to applied and theoretical aspects of implicit learning.

Attention↗
PubMed2001

Incidental learning of real-world regularities.

The large literature on incidental learning relies almost exclusively on laboratory experiments. Whenever researchers have attempted to demonstrate incidental learning of real-world regularities, they have typically failed to show learning. For example, it is well established that people do not learn regularities in everyday objects, such as the left-right orientation of faces on coins, despite a very large exposure to them. In this report, we examine this apparent contradiction. We argue that most studies exploring real-life incidental learning use tests that are not as sensitive to low-confidence information as those traditionally used in laboratory tasks. Using more sensitive measures, we show that it is possible to learn regularities from British and Japanese cultural life as a direct result of exposure to these regularities. Further, confidence measures suggest that although the information may be acquired incidentally, it can be expressed with and without concomitant awareness of that knowledge.

Adult↗
PubMed2001

Priming the access to names of famous faces.

There is a continuing controversy in models of face identification concerning the level of access to names relative to semantic information. In order to determine whether names are accessed sequentially after or in parallel to semantic information, we studied participants' speeded decisions about famous faces that were primed by partial semantic or partial name information. Decisions that required the access to the celebrity's name (one or more forename syllables, Expt 1) were significantly primed by partial name primes (initials or name fragments). However, at variance with sequential stage models, no reliable priming was observed by partial semantic primes (information about nationality, occupation, or whether a person was dead or alive). Moreover, there was a clear and consistent priming effect by partial semantic primes if the task was a nationality (British or American) decision that required the access to semantic information (Expt 2), demonstrating the effectiveness of these primes. The effects of partial name primes on nationality decisions were less consistent, with a significant effect for name fragments but not initials. However, effects of name primes were generally greater for syllable decisions than nationality decisions, and effects of semantic primes were generally greater for nationality decisions than syllable decisions. Taken together, these results favour a model of parallel rather than sequential access and suggest some degree of independence in the access to personal semantics and names.

Adult↗
PubMed1999

Asymmetric dependencies in perceiving identity and emotion: experiments with morphed faces.

We investigated whether an asymmetric relationship between the perception of identity and emotional expressions in faces (Schweinberger & Soukup, 1998) may be related to differences in the relative processing speed of identity and expression information. Stimulus faces were morphed across identity within a given emotional expression, or were morphed across emotion within a given identity. In Experiment 1, consistent classifications of these images were demonstrated across a wide range of morphing, with only a relatively narrow category boundary. At the same time, classification reaction times (RTs) reflected the increased perceptual difficulty of the morphed images. In Experiment 2, we investigated the effects of variations in the irrelevant dimension on judgments of faces with respect to a relevant dimension, using a Garner-type speeded classification task. RTs for expression classifications were strongly influenced by irrelevant identity information. In contrast, RTs for identity classifications were unaffected by irrelevant expression information, and this held even for stimuli in which identity was more difficult and slower to discriminate than expression. This suggests that differences in processing speed cannot account for the asymmetric relationship between identity and emotion perception. Theoretical accounts proposing independence of identity and emotion perception are discussed in the light of these findings.

Adult↗
PubMed1997

An instrument for the non-invasive objective assessment of velar function during speech.

This paper describes the development of a non-invasive, computer-based, clinical instrument that infers velar function by way of the measurement of nasal and oral airflow. The design criteria of the instrument were based upon a wide ranging review of current practice and available techniques. The instrument measures and displays both nasal and oral airflow, along with the envelope of the speech sound waveform. This allows the clinician to determine whether airflow is associated with oral or nasal airflow and, hence, to infer the position of the velum. Preliminary clinical trials suggest that the instrument provides valuable objective information about the movement of the soft palate, particularly within the time domain. Hence, it is believed that the device provides additional information for the assessment of velar function, complementing those techniques currently employed.

Biomedical Engineering↗
PubMed1997

The relationships between psychometric intelligence and learning in an explicit and an implicit task.

An experiment is reported examining the relation of implicit grammar learning and series completion tasks to a standard measure of psychometric intelligence, the Wechsler Adult Intelligence Scale-Revised (WAIS-R; D. Wechsler, 1981). The results replicate and extend an earlier study by A. S. Reber, F. F. Walkenfeld, and R. Hernstadt (1991) and provide the following support for the differences between explicit and implicit tasks: (a) The implicit task was less strongly related to Full Scale IQ, and (b) the implicit task appeared to be independent of age. The implicit and explicit tasks exhibited a quite different pattern of relations to the factors known to underlie WAIS-R performance. Although both tasks showed significant links with a Perceptual Organization factor, only the series completion task showed a significant link with the Attention factor.

Adult↗
PubMed1997

Investigating the relation between imagery and perception: evidence from face priming.

The relation between imagery and perception was investigated in face priming. Two experiments are reported in which subjects either saw or imagined the faces of celebrities. They were later given a speeded perceptual test (familiarity judgement to pictures of celebrities) or a speeded imagery test (in which they were told the names of celebrities and asked to make a decision about their appearance). Seeing faces primed the perceptual test, and imaging faces primed the imagery test; however, there was no priming between seeing and imaging faces. These results show that perception and imagery can be dissociated in normal subjects. In two further experiments, we examined the effects of imaging faces on a subsequent face-naming task and on a task requiring familiarity judgements to partial faces. Both these tasks were facilitated by prior imaging of faces. These results are discussed in relation to those of McDermott & Roediger (1994), who found that imagery promoted object priming in a perceptual test involving naming partial line drawings. The implications for models of face recognition are also discussed.

Eidetic Imagery↗
PubMed1996

Assessment in the treatment of hypernasal speech with motor neuron disease: a clinical report.

The application of nasal anemometry in this patient's treatment proved to be of value in obtaining an objective assessment of this intervention. Nasal anemometry may be of use in other situations, for example, (1) in preassessment and postassessment of cleft palate surgery and surgical interventions to improve the velopharyngeal seal (such as pharyngoplasty), (2) in the evaluation of nasalized speech with conventional speech therapy, (3) in the evaluation of nasalized speech by use of a palatal training appliance, and (4) in the investigation of snoring.

Denture, Partial↗
PubMed1990

Nasal airflow measurement using a compensated thermistor anemometer. Part 2. Computer signal processing and quantitative analysis.

A nasal anemometer is a useful tool for speech therapists in their assessment of treatment effectiveness. This work is the second part of a research scheme which describes how the system is compatible with the use of an IBM PC-AT microcomputer using a suitable analogue-to-digital convertor. This enables the system to perform signal processing and to display, draw, and calculate a numerical 'figure of merit' using Kendall's tau nonparametric correlation.

Cleft Palate↗
PubMed1989

Noninvasive beat-to-beat detection of ventricular late potentials.

The detection of ventricular late potentials is a subject of some clinical interest. Most techniques currently being investigated rely on signal averaging to extract the microvolt signals from the considerable amounts of noise which are present. Although this approach produces useful results, it does remove any beat-to-beat variations from the signal, and also requires that the signal be present for a considerable number of beats. The paper describes a technique for detecting ventricular late potentials from the body surface, which preserves beat-to-beat variations. The most important aspect of this technique is the use of an adaptive signal enhancer to minimise random noise. Representative results for one normal and two pathological subjects are presented and discussed. A comparison with signal averaging is made and the effectiveness of adaptive signal enhancement is illustrated.

Adult↗
PubMed1989

Simple fibre optic spectrophotometric cell for pH determination.

A simple, inexpensive fibre optic spectrophotometric cell has been developed for clinical use. The system may employ one of two indicator reagents for the measurement: phenol red and BDH universal indicator. The spectrophotometer uses two ultrabright LED sources and a PIN diode photodetector. The fibre is of the plastic type with a core diameter of 1.0 mm. Two alternative analytical methods are available: electronic or computer processing. In the case of phenol red the measuring range using computer processing is between 6.0 and 8.0 pH units, with an accuracy of 0.015 pH units. The range for electronic circuit processing is from 6.8 to 8.0 pH units with an accuracy of 0.02 pH units. Using a BDH universal indicator, the range for computer processing is between 5.5 and 8.5 pH units with an accuracy of 0.05 pH units, while with electronic processing the range is between 6.0 and 8.0 pH units with an accuracy of 0.03 pH units. A description of the optoelectronics, an analysis of the indicator reagents and the calibration procedure are presented here, together with some example results.

Calibration↗
PubMedDate not supplied

Globus pharyngis, personality, and psychological distress in the general population.

The authors approached 1,158 middle-aged women, who were assessed for the presence of the globus sensation in the prior 3 months. Seventy globus "cases" (6.0%) were identified. Twenty-eight women with globus and 35 control subjects completed a series of questionnaires designed to assess personality traits and psychological distress. The globus subjects were significantly higher on neuroticism and low on extra-version and had significantly elevated levels of psychological distress, including anxiety, low mood, and somatic concern when compared with the control subjects. Severity of throat symptoms, but not personality or psychological distress scores, predicted the degree of medical help sought for the symptom.

Adult↗
PubMedDate not supplied

Computer-assisted analysis of the echocardiogram in the clinical environment.

Ultrasound imaging of the heart can provide an important source of diagnostic data to the cardiologist, but conventional echocardiography requires considerable expertise, and is extremely time-consuming. Computer-based analysis is therefore very attractive and, in the light of decreasing hardware costs in recent years, has become increasingly viable in practice. This paper describes the specification and implementation of a computer-based tool which supports the clinician in the analysis of echocardiograms, exploiting the clinical judgement and inherent skill of the clinician. The design of the system has focused particularly on the provision of a powerful user interface for ease of interaction, flexibility in system functionality, and extensive interactive capabilities to maximize reliability and convenience of use. This paper will describe the principal features of the system and illustrate its use in the clinical environment.

Echocardiography↗