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Fourteen experiments investigate the 'first perspective alignment effect' (FPA), a novel finding that people sometimes encode a space preferentially in alignment with the first perspective they encounter. In Experiments 1--6, participants read verbal descriptions of three-path routes. A map-drawing task in Experiment 1 suggested that spatial memories are egocentrically encoded on the basis of forward-up equivalence. In experiments 3 and 4, when a salient landmark was described in relation to the start orientation of the routes, orientation estimates to remembered test locations were most accurate when participants imagined themselves aligned, rather than 180° contra-aligned, with the first part of the route. However, in Experiments 5 and 6 the introduction of allocentric cardinal term systematically affected the text FPA. Participants in Experiment 7 explored two versions of VEs based on the text descriptions used in Experiments 2--6. The FPA was found following the first VE exploration, but following the second VE exploration, the effect was attenuated. Experiment 8 omitted the alignment tests after the first VE, leading to similar results to those in the first test of Experiment 7, suggesting that prior experience of making orientation judgements in the first test of Experiment 7 had attenuated the FPA. Experiment 9 used a text-based procedure, in which participants were asked to make active spatial judgements after reading each section of the route, and the FPA was not found. Experiments 10--14 extended the above findings to learning about arrays of static objects from primary experience. In Experiment 10, when participants viewed an array of four objects from four perspectives, orientation judgements were similar for all perspectives. When arrays were viewed from two perspectives that were 0 and 90° (Experiment 11), and 0 and 180° (Experiment 12) misaligned from the centre of the array, no evidence for FPA encoding was found. The absence of this effect following primary, but not secondary learning Experiments 2--9; Wilson, 2001), was further investigated in Experiments 13 and 14, in which participants viewed the arrays under conditions of observer movement and display rotation. No evidence for FPA encoding was found; therefore, the presence of vestibular feedback in the primary case, does not explain differences in encoding between primary and secondary learning sources. The results are discussed in terms of spatial reference frames and spatial anchor points, and suggest that the FPA effect is the default form of encoding in spatial memory under some circumstances.

There can be no doubt that hunger is one of the most fundamentally important experiences in the life of every organism, and that it is a factor which has played a dominant part in the history of Man, and indeed of all animals, cannot be denied. No subject could be more profitably surveyed since its influence involves such vital issues. Despite the fact that hunger is so universal a problem one must admit that, compared with other questions arising in connection with our existence, the matter has received comparatively scanty attention. This state of affairs is due possibly to the fact that hunger, as a sensation,is hard to analyse since its disagreeable effect on consciousness induces other conflicting elements of an emotional nature so that a logical study of the already complex process is rendered more difficult. If hunger, regarded in its wider sense, does occur in animals it is probable that in them, lacking as they do the higher cerebral centres, the sensation is less complicated than in man, but, for obvious reasons, the study of the problem in them must be limited largely to objective phenomena secondary to hunger.

This thesis is about enactments of 'seeing' and how objects are made visible through digital imaging practices. Situated within a context of microscopy imaging and nanotechnological research, I investigate how seeing is tied to both the physical and digital acts of handling, moving or altering an object that is considered to be invisible. Utilizing an observational study of a nanotechnology lab and an environmental science facility. I look at purification, tinkering and touch as three specific manipulation practices that enact 'seeing'. As well as investigating the context of the lab, I also examine how images travel to other contexts where they are re-rendered for competitions and art-science collaborations. I argue that the necessity of these various practices for producing visibility demonstrates the importance of manipulation during imaging, and how seeing is an enactment, produced in and through material discursive acts. The project extends previous research in science and technology studies (STS) which has examined the situated and context-specific activity of scientific imaging, and also further elaborates on recent investigations into the role of gesture, embodiment and touch as a requirement for seeing. Overall, by drawing attention to acts of manipulation, this thesis highlights the role of hands and bodies in the production of scientific visualizations, further problematizing ideas of separation between subject/object and observer/observed.

Recent research has shown that people find it difficult to identify haptic objects when they feel them through a rigid probe, such as a stick or a rod, One explanation for these problems is that people's memory capacity is not large enough for them to remember all of the information that they gained about an object while they were feeling it. This thesis explores the idea that working as a 'pair might be able to help overcome some of the problems with memory and help to improve people's ability to identify haptic objects. Research has shown that pairs have better memory performance on tasks such as recalling information and identifying previously seen information than individuals do. This thesis explores the difference in performance between individuals and pairs in identifying haptic objects in a limited context. It limits its investigations to investigating the differences in performance under controlled lab conditions using time limited tasks with a small set of participants and objects. The work in this thesis shows that pairs do perform better than individuals do in the conditions that were studied and that the differences are likely due to memory. It serves as an initial investigation into the topic and suggests that further work would be worthwhile to investigate the generalisability of the findings. The thesis also investigates how haptic based CSCW may alter the performance of pairs and presents two techniques that alter communication and task division within a pair. The studies of these haptic systems found that they did alter communication and task division in beneficial ways under the conditions that they were observed.

It is a common practice to study the dynamics of sensory and cognitive processes using event-related potentials (ERPs) measured by placing electrodes on the scalp. These ERPs are very small in comparison with the on-going electroencephalogram (EEG) and are barely visible in the individual trials. Therefore, most ERP research relies on the identification of different waves after averaging several presentations of the same stimulus pattern. Although ensemble averaging improves the signal-to-noise-ratio, it implies a loss of information related to variations between the single-trials. In this thesis, I present an automatic denoising method based on the wavelet transform to obtain single-trial evoked potentials. The method is based on the inter- and intra-scale variability of the wavelet coefficients and their deviations from baseline values. The performance of the method is tested with simulated ERPs and with real visual and auditory ERPs. For the simulated data the method gives a significant improvement in the visualisation of single-trial ERPs as well as in the estimation of their amplitudes and latencies in comparison with the standard denoising technique (Donoho’s thresholding) and in comparison with the noisy single-trials. For the real data, the proposed method helps the identification of single-trial ERPs, providing a simple, automatic and fast tool that allows the study of single-trial responses and their correlations with behaviour. We used our proposed denoising algorithm to study the amplitude modulation of the ERP responses to the flashes of faces and to investigate whether the ERP responses in a visual and an auditory oddball paradigm were due to phase-resetting of on-going EEG (phase-resetting model) or due to additive neural responses adding to the background EEG in response to the stimulus presentation (additive model).

Listeners are often required to attend to speech in background noise. Coherent prosodic structure has been found to facilitate speech processing (Cutler, Dahan & Donselaar, 1997). The aim of this thesis is to investigate to what extent these prosodic cues, in particular fundamental frequency (FO), aid speech intelligibility in noise. Experiments measured Speech Reception Thresholds for sentences with different manipulations of their FO contour. These manipulations involved either a scaled reduction in FO variation, or the complete inversion of the FO contour. Experiments reported in Chapter 2 investigated the impact of these FO manipulations against speech-shaped noise and single-talker interferers. Inverting the FO contour was found to significantly degrade target speech intelligibility for both types of interferer, although a larger effect was observed with the single-talker interferer. No effect of altering the FO contour of the interferer was found. Low-pass filtering the FO contour (Chapter 3) showed that the most important frequencies lay at or below the syllable rate of speech, highlighting the importance of syllabic and suprasegmental fluctuations within the FO contour. Experiments in Chapter 4 compared synthesised and natural targets. Synthesised speech was found to be considerably less intelligible than natural speech. No consistent effect of FO inversion was noted for synthesised FO contours. However neither natural FO nor duration contours improved the intelligibility of the synthesised speech. Similar experiments using non-native English speakers (Chapter 5) showed a greater detriment to the perceived intelligibility of the speech with FO manipulations than for native speakers. Results are explained in terms of FO contours highlighting important content words. Intrinsic vowel pitch is also argued to contribute. Further study is required to determine why speech interferers caused listeners to rely more heavily on FO cues, and to investigate the influence of other prosodic cues on speech intelligibility.

In noisy conversations, listeners can segregate competing voices on the basis of their fundamental frequency (FO). The aim of this thesis was to investigate which mechanisms underlie this FO-segregation ability and whether this ability is affected by reverberation. This work provided evidence for a mechanism, which cancels interfering voices on the basis of their harmonic structure a process termed harmonic cancellation. We developed a paradigm in which listeners had to detect a band of noise masked by a harmonic or inharmonic complex masker (Chapter II). Harmonic cancellation was found to be beneficial up to about 3 kHz, sensitive to a degree of inharmonicity reflected by a peak autocorrelation of 0.9 or less, and to integrate harmonic information over very large bands. In addition to harmonic cancellation, listeners may also use FO as a sequential cue, provided that AFO is sufficiently large (Chapter III), in order to organise the auditory scene in the presence of several talkers a process termed sequential FO-grouping. By manipulating the FO of competing sources heard in anechoic or in reverberant environments, the Speech Reception Threshold (SRT) of a target voice masked by buzz (Chapter IV) or speech (Chapter V) interferers, was elevated when the interferer but not the target, was FO-modulated and especially in reverberation for the buzz interferer. These results were explained in terms of disruption of harmonic cancellation. Moreover, the benefit of an 8 semitone AFO was disrupted by reverberation even for monotonized sources, suggesting that reverberation is also detrimental to sequential FO-grouping. To conclude, the listener's ability to segregate voices by FO relies on the mechanisms of harmonic cancellation and sequential FO-grouping. Both these mechanisms are likely to be disrupted in realistic situations of conversation, i.e. real speech in reverberant rooms.