Reservoir Computing in Materio

Reservoir Computing first emerged as an efficient mechanism for training recurrent neural networks and later evolved into a general theoretical model for dynamical systems. By applying only a simple training mechanism many physical systems have become exploitable unconventional computers. However, at present, many of these systems require careful selection and tuning by hand to produce usable or optimal reservoir computers. In this thesis we show the first steps to applying the reservoir model as a simple computational layer to extract exploitable information from complex material substrates. We argue that many physical substrates, even systems that in their natural state might not form usable or "good" reservoirs, can be configured into working reservoirs given some stimulation. To achieve this we apply techniques from evolution in materio whereby configuration is through evolved input-output signal mappings and targeted stimuli. In preliminary experiments the combined model and configuration method is applied to carbon nanotube/polymer composites. The results show substrates can be configured and trained as reservoir computers of varying quality. It is shown that applying the reservoir model adds greater functionality and programmability to physical substrates, without sacrificing performance. Next, the weaknesses of the technique are addressed, with the creation of new high input-output hardware system and an alternative multi-substrate framework. Lastly, a substantial effort is put into characterising the quality of a substrate for reservoir computing, i.e its ability to realise many reservoirs. From this, a methodological framework is devised. Using the framework, radically different computing substrates are compared and assessed, something previously not possible. As a result, a new understanding of the relationships between substrate, tasks and properties is possible, outlining the way for future exploration and optimisation of new computing substrates

A systematic investigation reveals that Ishihara et al.'s (2008) STEARC effect only emerges when time is directly assessed

The Spatial-TEmporal Association of Response Codes (STEARC) effect (Ishihara et al. in Cortex 44:454-461, 2008) is evidence that time is spatially coded along the horizontal axis. It consists in faster left-hand responses to early onset timing and faster right-hand responses to late onset timing. This effect has only been established using tasks that directly required to assess onset timing, while no studies investigated whether this association occurs automatically in the auditory modality. The current study investigated the occurrence of the STEARC effect by using a procedure similar to Ishihara and colleagues. Experiment 1 was a conceptual replication of the original study, in which participants directly discriminated the onset timing (early vs. late) of a target sound after listening to a sequence of auditory clicks. This experiment successfully replicated the STEARC effect and revealed that the onset timing is mapped categorically. In Experiments 2, 3a and 3b participants were asked to discriminate the timbre of the stimuli instead of directly assessing the onset timing. In these experiments, no STEARC effect was observed. This suggests that the auditory STEARC effect is only elicited when time is explicitly processed, thus questioning the automaticity of this phenomenon

Gazing left, gazing right: exploring a spatial bias in social attention

Faces oriented rightwards are sometimes perceived as more dominant than faces oriented leftwards. In this study, we explored whether faces oriented rightwards can also elicit increased attentional orienting. Participants completed a discrimination task in which they were asked to discriminate, by means of a keypress, a peripheral target. At the same time, a task-irrelevant face oriented leftwards or rightwards appeared at the centre of the screen. The results showed that, while for faces oriented rightwards targets appearing on the right were responded to faster as compared to targets appearing on the left, for faces oriented leftwards no differences emerged between left and right targets. Furthermore, we also found a negative correlation between the magnitude of the orienting response elicited by the faces oriented leftwards and the level of conservatism of the participants. Overall, these findings provide evidence for the existence of a spatial bias reflected in social orienting

Clerical and manual workers' self and other images

The thesis takes as its starting point the explanation by David Lockwood of clerical anti-unionism in terms of a 'prestige' model of society, and of manual pro-unionism in terms of a 'class' model of society. The present author attempts to gather information about how clerks and manual workers see themselves and others in the work situation (self-image and other-image) in a manner which prestructures subject response as little as possible. The emphasis is thus upon meaning rather than behaviour as such. To this end Kelly repertory grid analysis is adapted and applied to clerks and manual workers in several research locations in North-West England. The data is processed for principal components and content analysed. Specific hypotheses are tested, including those that clerks will adopt a 'clerical stereotype' of workmindedness, impotence, selflessness, happiness and low union- mindedness, whilst manual workers adopt a 'manual stereotype' of low workmindedness, potency, egocentrism, unhappiness, and unionmindedness. All subjects in both occupational groups are found to espouse the clerical stereotype, despite being almost all union members. The stereotypes are related to Lockwood's society images and are found to be congruent in some respects, but different in others, chiefly in the use by our subjects of the variables of potency and egocentrism. Union membership, where a relationship can be directly tested, is found to be associated with impotence and workmindedness. Most of our subjects are anti-union in orientation. Their union membership is a product of external factors which have not influenced their self and other - images. The relationship between psychological and sociological perspectives is discussed. By the use of an unusual but appropriate method of investigation it is hoped that an original contribution is made to the theoretical and empirical understanding of the way clerks and manual workers see aspects of their work situations

Patterns of young participation in higher education : a geographical analysis of England, 1994-2000

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

The Sequence of Standard and Target in Pairwise Magnitude Comparisons

The present research introduces the effect of the presentation order of target and standard in paired magnitude comparisons on comparison performance. So far, this effect has been overlooked by most of the domains of psychological research on comparative thinking. The standard-target-sequence-effect (STSE) was demonstrated in eight out of eleven experiments (N = 1,018) presented in the work at hand. Participants repetitively performed simple magnitude comparisons of two objects (e.g. one digit numbers or geometric shapes) in various economic and social contexts. Results revealed a stable performance advantage (in terms of speed and accuracy) for trials in which the standard stimulus was encountered before the to be judged target stimulus. In three experiments the STSE could not be observed, most likely because of the relative spatial and temporal positions of stimuli. The diverse findings and experimental set ups are discussed as well as the underlying mechanism, the interaction of the STSE with the SNARC effect for numerical comparisons (Dehaene, Dupoux & Mehler, 1990; Dehaene, Bossini & Giraux, 1993; Fisher, Castel, Dodd & Pratt, 2003) and the ascending order advantage in magnitude judgement tasks (Turconi, Campbell & Seron, 2006; Müller & Schwarz, 2008; Schroeder, Nuerk & Plewnia, 2017). The effect of the order of target and standard on comparison processes had been mentioned in signal detection and stimuli discrimination tasks in psychophysics (so called Type B Effect, e.g. Dijas & Ulrich, 2014), while social and cognitive psychologists’ research on judgements of similarity and contrast have provided inconsistent results for the influence of the sequence of standard and target on the comparison process (e.g. Tversky, 1978; Agostinelli, Sherman, Fazio & Hearst, 1986). Researchers on symbolic pairwise comparisons did not report such an effect at all. The research on the STSE outlined in the work at hand contributes to an interdisciplinary understanding of order effects of target and standard as well as to the debate on the origins of order effects in general and on the basic principles of comparative thinking

Engineering data compendium. Human perception and performance. User's guide

The concept underlying the Engineering Data Compendium was the product of a research and development program (Integrated Perceptual Information for Designers project) aimed at facilitating the application of basic research findings in human performance to the design and military crew systems. The principal objective was to develop a workable strategy for: (1) identifying and distilling information of potential value to system design from the existing research literature, and (2) presenting this technical information in a way that would aid its accessibility, interpretability, and applicability by systems designers. The present four volumes of the Engineering Data Compendium represent the first implementation of this strategy. This is the first volume, the User's Guide, containing a description of the program and instructions for its use

Large as being on top of the world and small as hitting the roof: A shared magnitude representation for the comparison of emotions and numbers

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Previous work on the direct Speed–Intensity Association (SIA) on comparative judgment tasks involved spatially distributed responses over spatially distributed stimuli with high motivational significance like facial expressions of emotions. This raises the possibility that the inferred stimulus-driven regulation of lateralized motor reactivity described by SIA, which was against the one expected on the basis of a valence-specific lateral bias, was entirely due to attentional capture from motivational significance (beyond numerical cognition). In order to establish the relevance of numerical cognition on the regulation of attentional capture we ran two complementary experiments. These involved the same direct comparison task on stimulus pairs that were fully comparable in terms of their analog representation of intensity but with different representational domain and motivational significance: symbolic magnitudes with low motivational significance in experiment 1 vs. emotions with rather high motivational significance in experiment 2. The results reveal a general SIA and point to a general mechanism regulating comparative judgments. This is based on the way spatial attention is captured toward locations that contain the stimulus which is closest in term of relative intensity to the extremal values of the series, regardless from its representational domain being it symbolic or emotiona