Neglect dyslexia with a stimulus-centred deficit and without visuospatial neglect.

This paper reports a single case of ipsilesional left neglect dyslexia and interprets it according to the three-level model of visual word recognition proposed by Caramazza and Hillis (1990). The three levels reflect a progression from the physical stimulus to an abstract representation of a word. RR was not impaired at the first, retinocentric, level, which represents the individual features of letters within a word according to the location of the word in the visual field: She made the same number of errors to words presented in her left visual field as in her right visual field. A deficit at this level should also mean the patient neglects all stimuli. This did not occur with RR: She did not neglect when naming the items in rows of objects and rows of geometric symbols. In addition, although she displayed significant neglect dyslexia when making visual matching judgements on pairs of words and nonwords, she did not do so to pairs of nonsense letter shapes, shapes which display the same level of visual complexity as letters in words. RR was not impaired at the third, graphemic, level, which represents the ordinal positions of letters within a word: She continued to neglect the leftmost (spatial) letter of words presented in mirror-reversed orientation and she did not neglect in oral spelling. By elimination, these results suggest RR's deficit affects a spatial reference frame where the representational space is bounded by the stimulus: A stimulus-centred level of representation. We define five characteristics of a stimulus-centred deficit, as manifest in RR. First, it is not the case that neglect dyslexia occurs because the remaining letters in a string attract or capture attention away from the leftmost letter(s). Second, the deficit is continuous across the letter string. Third, perceptually significant features, such as spaces, define potential words. Fourth, the whole, rather than part, of a letter is neglected. Fifth, category information is preserved. It is concluded that the Caramazza-Hillis model accounts well for RR's data, although we conclude that neglect dyslexia can be present when a more general visuospatial neglect is absent.

Gait termination in young and older adults : effect of stopping stimulus probability and stimulus delay

Sixteen young (25±2.6 years) and 16 older individuals (69±4.4 years) walked normally then terminated walking rapidly. A visual stopping stimulus was presented 10 ms following ground contact (short delay) and in another condition, at 450 ms prior to toe-off (long delay). Stimulus probability was either high (80% of trials) or low (10%). The younger group stopped faster (463 vs. 574 ms) despite also walking faster (1.29 vs. 1.17 m s⁻¹). Longer delay decreased one-step responses but older participants used significantly more (slower) two-step stopping, which increased stopping time and distance. The additional step may have been pre-planned to maintain medial–lateral stability.

Reconstituting the invisible out of structure and repetition: a walk through diary V3.2.

This presentation will discuss the production of an interactive personal diary constructed in digital form as an interactive CD-Rom: Diary V 3.2. This diary was conceived as a digital version of the family photo album of the artist's nuclear family, which unfortunately disintegrated during 4 years of the diary's making. As a result Diary V 3.2 became more a documentation of the mood and state of mind of the maker than the family it began to focus on. It acted more as a trace or a remnant of mood, an artifact of loss. This was communicated not so much through narrative but ideas of loss and erasure. Another layer to this work concerns the migration of images, technique from the old analogue technology to the new digital technology which can act as a replay of the migrant experience.

Procedural learning in children with developmental coordination disorder

Despite the fact that developmental coordination disorder (DCD) is characterised by a deficit in the ability to learn or automate motor skills, few studies have examined motor learning over repeated trials. In this study we examined procedural learning in a group of 10 children with DCD (aged 8–12 years) and age-matched controls without DCD. The learning task was modelled on that of Nissen and Bullemer [Cognitive Psychology 19 (1987) 1]. Children performed a serial reaction time (SRT) task in which they were required to learn a spatial sequence that repeated itself every 10 trials. Children were not aware of the repetition. Spatial targets were four (horizontal) locations presented on a computer monitor. Children responded using four response keys with the same horizontal mapping as the stimulus. They were tested over five blocks of 100 trials each. The first four blocks presented the same repeating sequence, while the fifth block was randomised. Procedural learning was indexed by the slope of the regression of RT on blocks 1–4. Results showed that most children displayed strong procedural learning of the sequence, despite having no explicit knowledge about it. Overall, there was no group difference in the magnitude of learning over blocks of trials – most children performed within the normal range. Procedural learning for simple sequential movements appears to be intact in children with DCD. This suggests that cortico-striatal circuits that are strongly implicated in the sequencing of simple movements appear to be function normally in DCD.

The effect of Shamanic-like stimulus conditions and the cognitive-perceptual factor of schizotypy on phenomenology

Shamanism has remained an integral part of indigenous healing rituals since ancient times and is currently attracting interest as a complementary therapeutic technique in psychology. Recently, shamanic-like techniques have been used to facilitate changes in the phenomenology of nonshamans. However, such research has largely been delimited to a single shamanic-like technique (i.e., drumming), and the role of personality traits with regards to receptivity to this technique has been neglected. The purpose of the present study was to investigate experimentally the effect of different shamanic-like techniques and the cognitive-perceptual factor of the schizotypy construct on phenomenology. One hundred and four non-shamans were randomly assigned to one of three conditions: Drumming, Ganzfeld, or Sitting Quietly with Eyes Open. Participants' phenomenology was assessed using the Phenomenology of Consciousness Inventory, Phenomenology associated with shamanic-like techniques appeared to be statistically significantly different from phenomenology associated with sitting quietly with eyes open. Furthermore, high cognitive-perceptual participants reported significant alterations in phenomenology compared to their low cognitive-perceptual counterparts. Methodological shortcomings of the present study are discussed and suggestions for future research are advanced.

Stimulus determinants and receptor mechanisms involved in the tactual perception of woollen fabrics

The dimensions of touch sensations were investigated in a series of human psychophysical experiments using woollen fabrics as stimuli and words from the textile industry literature as verbal descriptors of touch sensations. Roughness was shown to be an important dimension and was found to be encoded by two out of the four receptors in the skin that respond to specific frequencies of mechanical vibration.

Neurophysiological responses after short-term strength training of the biceps brachii muscle

The neural adaptations that mediate the increase in strength in the early phase of a strength training program are not well understood; however, changes in neural drive and corticospinal excitability have been hypothesized. To determine the neural adaptations to strength training, we used transcranial magnetic stimulation (TMS) to compare the effect of strength training of the right elbow flexor muscles on the functional properties of the corticospinal pathway. Motorevoked potentials (MEPs) were recorded from the right biceps brachii (BB) muscle from 23 individuals (training group; n = 13 and control group; n = 10) before and after 4 weeks of progressive overload strength training at 80% of 1-repetition maximum (1 RM). The TMS was delivered at 10% of the root mean square electromyographic signal (rmsEMG) obtained from a maximal voluntary contraction (MVC) at intensities of 5% of stimulator output below active motor threshold (AMT) until saturation of the MEP (MEP maxl. Strength training resulted in a 28% (p = 0.0001) increase in 1 RM strength, and this was accompanied by a 53% increase (p = 0.05) in the amplitude of the MEP at AMT; 33% (p = 0.05) increase in MEP at 20% above AMT, and a 38% increase at MEPmax (p = 0.04). There were no significant differences in the estimated slope (p = 0.4 7) or peak slope of the stimulus-response curve for the left primary motor cortex (M1) after strength training (p = 0.61). These results demonstrate that heavy-load isotonic strength training alters neural transmission via the corticospinal pathway projecting to the motoneurons controlling BB and in part underpin the strength changes observed in this study.

Cognitive intervention in autism using multimedia stimulus

We demonstrate an open multimedia-based system for delivering early intervention therapy for autism. Using exible multi-touch interfaces together with principled ways to access rich content and tasks, we show how a syllabus can be translated into stimulus sets for early intervention. Media stimuli are able to be presented agnostic to language and media modality due to a semantic network of concepts and relations that are fundamental to language and cognitive development, which enable stimulus complexity to be adjusted to child performance. Being open, the system is able to assemble enough media stimuli to avoid children over-learning, and is able to be customised to a specific child which aids with engagement. Computer-based delivery enables automation of session logging and reporting, a fundamental and time-consuming part of therapy.