Robert P Carlyon

Mrc Harwell, Oxford, England, United Kingdom

Are you Robert P Carlyon?

Claim your profile

Publications (219)444.95 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: We assessed auditory sensitivity to three classes of temporal-envelope statistics (modulation depth, modulation rate, and comodulation) that are important for the perception of 'sound textures'. The textures were generated by a probabilistic model that prescribes the temporal statistics of a selected number of modulation envelopes, superimposed onto noise carriers. Discrimination thresholds were measured for normal-hearing (NH) listeners and users of a MED-EL pulsar cochlear implant (CI), for separate manipulations of the average rate and modulation depth of the envelope in each frequency band of the stimulus, and of the co-modulation between bands. Normal-hearing (NH) listeners' discrimination of envelope rate was similar for baseline modulation rates of 5 and 34 Hz, and much poorer than previously reported for sinusoidally amplitude-modulated sounds. In contrast, discrimination of model parameters that controlled modulation depth was poorer at the lower baseline rate, consistent with the idea that, at the lower rate, subjects get fewer 'looks' at the relevant information when comparing stimuli differing in modulation depth. NH listeners could discriminate differences in co-modulation across bands; a multidimensional scaling study revealed that this was likely due to genuine across-frequency processing, rather than within-channel cues. CI users' discrimination performance was worse overall than for NH listeners, but showed a similar dependence on stimulus parameters.
    No preview · Article · Dec 2015 · Hearing research
  • Robert P. Carlyon · John M. Deeks
    [Show abstract] [Hide abstract]
    ABSTRACT: Four experiments measured the perceptual and neural correlates of the temporal pattern of electrical stimulation applied to one cochlear-implant (CI) electrode, for several subjects. Neural effects were estimated from the electrically evoked compound action potential (ECAP) to each pulse. Experiment 1 attenuated every second pulse of a 200-pps pulse train. Increasing attenuation caused pitch to drop and the ECAP to become amplitude modulated, thereby providing an estimate of the relationship between neural modulation and pitch. Experiment 2 showed that the pitch of a 200-pps pulse train can be reduced by delaying every second pulse, so that the inter-pulse-intervals alternate between longer and shorter intervals. This caused the ECAP to become amplitude modulated, but not by enough to account for the change in pitch. Experiment 3 replicated the finding that rate discrimination deteriorates with increases in baseline rate. This was accompanied by an increase in ECAP modulation, but by an amount that produced only a small effect on pitch in experiment 1. Experiment 4 showed that preceding a pulse train with a carefully selected "pre-pulse" could reduce ECAP modulation, but did not improve rate discrimination. Implications for theories of pitch and for limitations of pitch perception in CI users are discussed.
    No preview · Article · Nov 2015 · The Journal of the Acoustical Society of America
  • B. Kenway · Y.C. Tam · Z. Vanat · F. Harris · R. Gray · J. Birchall · R. Carlyon · P. Axon
    [Show abstract] [Hide abstract]
    ABSTRACT: Objective: To assess differences in pitch-ranking ability across a range of speech understanding performance levels and as a function of electrode position. Study Design: An observational study of a cross-section of cochlear implantees. Setting: Tertiary referral center for cochlear implantation. Patients: A total of 22 patients were recruited. All three manufacturers' devices were included (MED-EL, Innsbruck, Austria, n=10; Advanced Bionics, California, USA, n=8; and Cochlear, Sydney, Australia, n=4) and all patients were long-term users (more than 18 months). Twelve of these were poor performers (scores on BKB sentence lists <60%) and 10 were excellent performers (BKB >90%). Intervention: After measurement of threshold and comfort levels, and loudness balancing across the array, all patients underwent thorough pitch-ranking assessments at 80% of comfort levels. Main Outcome Measure: Ability to discriminate pitch across the electrode array, measured by consistency in discrimination of adjacent pairs of electrodes, as well as an assessment of the pitch order across the array using the midpoint comparison task. Results: Within the poor performing group there was wide variability in ability to pitch rank, from no errors, to a complete inability to reliably and consistently differentiate pitch change across the electrode array. Good performers were overall significantly more accurate at pitch ranking (p=0.026). Consistent pitch ranking was found to be a significant independent predictor of BKB score, even after adjusting for age. Users of the MED-EL implant experienced significantly more pitch confusions at the apex than at more basal parts of the electrode array. Conclusions: Many cochlear implant users struggle to discriminate pitch effectively. Accurate pitch ranking appears to be an independent predictor of overall outcome. Future work will concentrate on manipulating maps based upon pitch discrimination findings in an attempt to improve speech understanding.
    No preview · Article · Oct 2015
  • Source
    Stefano Cosentino · John M. Deeks · Robert P. Carlyon
    [Show abstract] [Hide abstract]
    ABSTRACT: Behavioral measures of spatial selectivity in cochlear implants are important both for guiding the programing of individual users’ implants and for the evaluation of different stimulation methods. However, the methods used are subject to a number of confounding factors that can contaminate estimates of spatial selectivity. These factors include off-site listening, charge interactions between masker and probe pulses in interleaved masking paradigms, and confusion effects in forward masking. We review the effects of these confounds and discuss methods for minimizing them. We describe one such method in which the level of a 125-pps masker is adjusted so as to mask a 125-pps probe, and where the masker and probe pulses are temporally interleaved. Five experiments describe the method and evaluate the potential roles of the different potential confounding factors. No evidence was obtained for off-site listening of the type observed in acoustic hearing. The choice of the masking paradigm was shown to alter the measured spatial selectivity. For short gaps between masker and probe pulses, both facilitation and refractory mechanisms had an effect on masking; this finding should inform the choice of stimulation rate in interleaved masking experiments. No evidence for confusion effects in forward masking was revealed. It is concluded that the proposed method avoids many potential confounds but that the choice of method should depend on the research question under investigation.
    Full-text · Article · Sep 2015 · Trends in hearing
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Objective: Electrically evoked compound action potentials (ECAPs) have been employed as a measure of neural activation evoked by cochlear implant (CI) stimulation. A forward-masking procedure is commonly used to reduce stimulus artefacts. This method estimates the joint neural activation produced by two electrodes - one acting as probe and the other as masker; as such, the measured ECAPs depend on the activation patterns produced by both. We describe an approach - termed Panoramic ECAP ("PECAP") - that allows reconstruction of the underlying neural activation pattern of individual channels from ECAP amplitudes. Methods: The proposed approach combines two constrained nonlinear optimization stages. PECAP was validated against simulated and physiological data from CI users. The physiological data consisted of ECAPs measured from four users of Cochlear® devices. For each subject, an 18×18 ECAP amplitude matrix was measured using a forward-masking method. Results: The results from computer simulations indicate that our approach can reliably estimate the underlying activation patterns from ECAP amplitudes even for instances of neural "dead regions" or cross-turn stimulation. The operating signal-to-noise ratio (SNR) for the proposed algorithm was 5 dB or higher, which matched well the SNR measured from human physiological data. Human ECAPs were fitted with our procedure to determine neural activation patterns. Conclusion: PECAP can be used to identify undesirable features of the neural activation pattern of individual CI users. Significance: Our approach may have clinical application as an objective measure of electrode-to-neuron interface and may be used to devise ad hoc stimulation strategies.
    Full-text · Article · Sep 2015 · IEEE transactions on bio-medical engineering
  • [Show abstract] [Hide abstract]
    ABSTRACT: The frequency following response (FFR) is a scalp-recorded measure of phase-locked brainstem activity to stimulus-related periodicities. Three experiments investigated the specificity of the FFR for carrier and modulation frequency using adaptation. FFR waveforms evoked by alternating-polarity stimuli were averaged for each polarity and added, to enhance envelope, or subtracted, to enhance temporal fine structure information. The first experiment investigated peristimulus adaptation of the FFR for pure and complex tones as a function of stimulus frequency and fundamental frequency (F0). It showed more adaptation of the FFR in response to sounds with higher frequencies or F0s than to sounds with lower frequency or F0s. The second experiment investigated tuning to modulation rate in the FFR. The FFR to a complex tone with a modulation rate of 213 Hz was not reduced more by an adaptor that had the same modulation rate than by an adaptor with a different modulation rate (90 or 504 Hz), thus providing no evidence that the FFR originates mainly from neurons that respond selectively to the modulation rate of the stimulus. The third experiment investigated tuning to audio frequency in the FFR using pure tones. An adaptor that had the same frequency as the target (213 or 504 Hz) did not generally reduce the FFR to the target more than an adaptor that differed in frequency (by 1.24 octaves). Thus, there was no evidence that the FFR originated mainly from neurons tuned to the frequency of the target. Instead, the results are consistent with the suggestion that the FFR for low-frequency pure tones at medium to high levels mainly originates from neurons tuned to higher frequencies. Implications for the use and interpretation of the FFR are discussed.
    No preview · Article · Jul 2015 · Journal of the Association for Research in Otolaryngology
  • Source
    Robert P Carlyon · John M Deeks · Colette M McKay
    [Show abstract] [Hide abstract]
    ABSTRACT: To further understand the response of the human brainstem to electrical stimulation, a series of experiments compared the effect of pulse rate and polarity on detection thresholds between auditory brainstem implant (ABI) and cochlear implant (CI) patients. Experiment 1 showed that for 400-ms pulse trains, ABI users' thresholds dropped by about 2 dB as pulse rate was increased from 71 to 500 pps, but only by an average of 0.6 dB as rate was increased further to 3500 pps. This latter decrease was much smaller than the 7.7-dB observed for CI users. A similar result was obtained for pulse trains with a 40-ms duration. Furthermore, experiment 2 showed that the threshold difference between 500- and 3500-pps pulse trains remained much smaller for ABI than for CI users, even for durations as short as 2 ms, indicating the effect of a fast-acting mechanism. Experiment 3 showed that ABI users' thresholds were lower for alternating-polarity than for fixed-polarity pulse trains, and that this difference was greater at 3500 pps than at 500 pps, consistent with the effect of pulse rate on ABI users' thresholds being influenced by charge interactions between successive biphasic pulses. Experiment 4 compared thresholds and loudness between trains of asymmetric pulses of opposite polarity, in monopolar mode, and showed that in both cases less current was needed when the anodic, rather than the cathodic, current was concentrated into a short time interval. This finding is similar to that previously observed for CI users and is consistent with ABI users being more sensitive to anodic than cathodic current. We argue that our results constrain potential explanations for the differences in the perception of electrical stimulation by CI and ABI users, and have potential implications for future ABI stimulation strategies.
    Full-text · Article · Jul 2015 · Journal of the Association for Research in Otolaryngology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Monaural rate discrimination and binaural interaural time difference (ITD) discrimination were studied as functions of pulse rate in a group of bilaterally implanted cochlear implant users. Stimuli for the rate discrimination task were pulse trains presented to one electrode, which could be in the apical, middle, or basal part of the array, and in either the left or the right ear. In each two-interval trial, the standard stimulus had a rate of 100, 200, 300, or 500 pulses per second and the signal stimulus had a rate 35 % higher. ITD discrimination between pitch-matched electrode pairs was measured for the same standard rates as in the rate discrimination task and with an ITD of +/- 500 μs. Sensitivity (d') on both tasks decreased with increasing rate, as has been reported previously. This study tested the hypothesis that deterioration in performance at high rates occurs for the two tasks due to a common neural basis, specific to the stimulation of each electrode. Results show that ITD scores for different pairs of electrodes correlated with the lower rate discrimination scores for those two electrodes. Statistical analysis, which partialed out overall differences between listeners, electrodes, and rates, supports the hypothesis that monaural and binaural temporal processing limitations are at least partly due to a common mechanism.
    Full-text · Article · Jun 2015 · Journal of the Association for Research in Otolaryngology
  • [Show abstract] [Hide abstract]
    ABSTRACT: One task intended to measure sensitivity to temporal fine structure (TFS) involves the discrimination of a harmonic complex tone from a tone in which all harmonics are shifted upwards by the same amount in hertz. Both tones are passed through a fixed bandpass filter centered on the high harmonics to reduce the availability of excitation-pattern cues and a background noise is used to mask combination tones. The role of frequency selectivity in this "TFS1" task was investigated by varying level. Experiment 1 showed that listeners performed more poorly at a high level than at a low level. Experiment 2 included intermediate levels and showed that performance deteriorated for levels above about 57 dB sound pressure level. Experiment 3 estimated the magnitude of excitation-pattern cues from the variation in forward masking of a pure tone as a function of frequency shift in the complex tones. There was negligible variation, except for the lowest level used. The results indicate that the changes in excitation level at threshold for the TFS1 task would be too small to be usable. The results are consistent with the TFS1 task being performed using TFS cues, and with frequency selectivity having an indirect effect on performance via its influence on TFS cues.
    No preview · Article · May 2015 · The Journal of the Acoustical Society of America
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Cochlear implant (CI) users usually exhibit marked across-electrode differences in detection thresholds with Bfocused^ modes of stimulation, such as partial-tripolar (pTP) mode. This may reflect differences either in local neural survival or in the distance of the electrodes from the modiolus. To shed light on these two explanations, we compared stimulus-detection thresholds and gap-detection thresholds (GDTs) at comfortably loud levels for at least four electrodes in each of ten Advanced Bionics CI users, using 1031-pps pulse trains. The electrodes selected for each user had a wide range of stimulus-detection thresholds in pTP mode. We also measured across-electrode variations in both stimulus-detection and gap-detection tasks in monopolar (MP) mode. Both stimulus-detection and gap-detection thresholds correlated across modes. However, there was no significant correlation between stimulus-detection and gap-detection thresholds in either mode. Hence, gap-detection thresholds likely tap a source of across-electrode variation additional to, or different from, that revealed by stimulus-detection thresholds. Stimulus-detection thresholds were significantly lower for apical than for basal electrodes in both modes; this was only true for gap detection in pTP mode. Finally, although the across-electrode standard deviation in stimulus-detection thresholds was greater in pTP than in MP mode, the reliability of these differences—assessed by dividing the across-electrode standard deviation by the stan-dard deviation across adaptive runs for each electrode—was similar for the two modes; this metric was also similar across modes for gap detection. Hence across-electrode differences can be revealed using clinically available MP stimula-tion, with a reliability comparable to that observed with focused stimulation.
    Full-text · Article · Feb 2015 · Journal of the Association for Research in Otolaryngology
  • Olivier Macherey · Robert P Carlyon
    [Show abstract] [Hide abstract]
    ABSTRACT: Five normally hearing listeners pitch-ranked harmonic complexes of different fundamental frequencies (F0s) filtered in three different frequency regions. Harmonics were summed either in sine, alternating sine-cosine (ALT), or pulse-spreading (PSHC) phase. The envelopes of ALT and PSHC complexes repeated at rates of 2F0 and 4F0. Pitch corresponded to those rates at low F0s, but, as F0 increased, there was a range of F0s over which pitch remained constant or dropped. Gammatone-filterbank simulations showed that, as F0 increased and the number of harmonics interacting in a filter dropped, the output of that filter switched from repeating at 2F0 or 4F0 to repeating at F0. A model incorporating this phenomenon accounted well for the data, except for complexes filtered into the highest frequency region (7800-10 800 Hz). To account for the data in that region it was necessary to assume either that auditory filters at very high frequencies are sharper than traditionally believed, and/or that the auditory system applies smaller weights to filters whose outputs repeat at high rates. The results also provide evidence on the highest pitch that can be derived from purely temporal cues, and corroborate recent reports that a complex pitch can be derived from very-high-frequency resolved harmonics.
    No preview · Article · Dec 2014 · The Journal of the Acoustical Society of America
  • Source
    Robert P. Carlyon · Jolijn Monstrey · John M. Deeks · Olivier Macherey
    [Show abstract] [Hide abstract]
    ABSTRACT: Objective: To evaluate a speech-processing strategy in which the lowest frequency channel is conveyed using an asymmetric pulse shape and “phantom stimulation”, where current is injected into one intra-cochlear electrode and where the return current is shared between an intra-cochlear and an extra-cochlear electrode. This strategy is expected to provide more selective excitation of the cochlear apex, compared to a standard strategy where the lowest-frequency channel is conveyed by symmetric pulses in monopolar mode. In both strategies all other channels were conveyed by monopolar stimulation. Design: Within-subjects comparison between the two strategies. Four experiments: (1) discrimination between the strategies, controlling for loudness differences, (2) consonant identification, (3) recognition of lowpass-filtered sentences in quiet, (4) sentence recognition in the presence of a competing speaker. Study sample: Eight users of the Advanced Bionics CII/Hi-Res 90k cochlear implant. Results: Listeners could easily discriminate between the two strategies but no consistent differences in performance were observed. Conclusions: The proposed method does not improve speech perception, at least in the short term.
    Full-text · Article · Oct 2014 · International Journal of Audiology
  • Olivier Macherey · Robert P. Carlyon
    [Show abstract] [Hide abstract]
    ABSTRACT: Cochlear implants are the first example of a neural prosthesis that can substitute a sensory organ: they bypass the malfunctioning auditory periphery of profoundly-deaf people to electrically stimulate their auditory nerve. The history of cochlear implants dates back to 1957, when Djourno and Eyriès managed, for the first time, to elicit sound sensations in a deaf listener using an electrode implanted in his inner ear. Since then, considerable technological and scientific advances have been made. Worldwide, more than 300,000 deaf people have been fitted with a cochlear implant; it has become a standard clinical procedure for born-deaf children and its success has led over the years to relaxed patient selection criteria; for example, it is now not uncommon to see people with significant residual hearing undergoing implantation. Although the ability to make sense of sounds varies widely among the implanted population, many cochlear implant listeners can use the telephone and follow auditory-only conversations in quiet environments.
    No preview · Article · Sep 2014 · Current Biology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Under binaural listening conditions, the detection of target signals within background masking noise is substantially improved when the interaural phase of the target differs from that of the masker. Neural correlates of this 'Binaural masking level difference' (BMLD) have been observed in the inferior colliculus and temporal cortex, but it is not known whether degeneration of the inferior colliculus would result in a reduction of the BMLD in humans. We used magnetoencephalography to examine the BMLD in 13 healthy adults and 13 patients with progressive supranuclear palsy (PSP). PSP is associated with severe atrophy of the upper brain stem, including the inferior colliculus, confirmed by voxel-based morphometry of structural MRI. Stimuli comprised in-phase sinusoidal tones presented to both ears at three levels (high, medium and low) masked by in-phase noise which rendered the low-level tone inaudible. Critically, the BMLD was measured using a low-level tone presented in opposite phase across ears, making it audible against the noise. The cortical waveforms from bilateral auditory sources revealed significantly larger N1m peaks for the out-of-phase low-level tone compared to the in-phase low-level tone, for both groups, indicating preservation of early cortical correlates of the BMLD in PSP. In PSP a significant delay was observed in the onset of the N1m deflection and the amplitude of the P2m was reduced, but these differences were not restricted to the BMLD condition. The results demonstrate that although PSP causes subtle auditory deficits, binaural processing can survive the presence of significant damage to the upper brain stem.
    Full-text · Article · Sep 2014 · Journal of Neurophysiology
  • Hedwig E Gockel · Sami Alsindi · Charles Hardy · Robert P Carlyon
    [Show abstract] [Hide abstract]
    ABSTRACT: There is evidence that the contribution of a given harmonic in a complex tone to residue pitch is influenced by the accuracy with which the frequency of that harmonic is encoded. We investigated whether listeners adjust the weights assigned to individual harmonics based on acquired knowledge of the reliability of the frequency estimates of those harmonics. In a two-interval forced-choice task, seven listeners indicated which of two 12-harmonic complex tones had the higher overall pitch. In context trials (60% of all trials), the fundamental frequency (F0) was 200 Hz in one interval and 200+ΔF0 Hz in the other. In different blocks, either the third or the fourth harmonic, plus (always) the seventh, ninth, and 12th harmonics were replaced by narrowband noises that were identical in the two intervals. Feedback was provided. In test trials (40% of all trials), the fundamental frequency was 200+ΔF0/2 Hz in both intervals and either the third or the fourth harmonic was shifted slightly up or down in frequency. There were no narrowband noises. Feedback was not provided. The results showed that substitution of a harmonic by noise in context trials significantly reduced the contribution of that harmonic to pitch judgments in the test trials.
    No preview · Article · Apr 2014 · The Journal of the Acoustical Society of America
  • Ingrid Johnsrude · Elizabeth Casey · Robert P Carlyon
    [Show abstract] [Hide abstract]
    ABSTRACT: We studied the effect of voice familiarity on the ability to segregate one voice from a competing speaker. Specifically, we examine the utility of arguably the most familiar voice of all-the mother's voice-in facilitating segregation, and compared it to the effect of a voice that listeners had been familiarized with in the laboratory. We tested 19 older adolescents (still living at home) on a version of the coordinate-response-measure procedure (CRM; Bolia et al., 2001), with mixtures of two voices, at three signal-to-noise ratios (Ő3 dB, 0 dB, + 3 dB). Performance was better when the mother's voice was the target, compared both to novel and lab-familiar targets. At the most disadvantageous target-to-masker ratio (Ő3 dB), listeners were also better able to ignore their mother's voice so as to comprehend a stranger's voice more effectively, demonstrating that extremely familiar voice information facilitates segregation. This pattern of results is similar to that observed with older people (aged 44-59) when their spouse's voice was present in a two-voice CRM mixture (Johnsrude et al., 2013). The new results demonstrate the importance of long-term (rather than short-term) familiarity and show that it aids sound segregation for adolescents as well as older adults.
    No preview · Article · Apr 2014 · The Journal of the Acoustical Society of America
  • Andrew J Oxenham · Robert P Carlyon
    [Show abstract] [Hide abstract]
    ABSTRACT: The Gold Medal is presented in the spring to a member of the Society, without age limitation, for contributions to acoustics. The first Gold Medal was presented in 1954 on the occasion of the Society's Twenty-Fifth Anniversary Celebration and biennially until 1981. It is now an annual award.
    No preview · Article · Apr 2014 · The Journal of the Acoustical Society of America
  • Robert P Carlyon
    [Show abstract] [Hide abstract]
    ABSTRACT: Roy Patterson and Brian Moore, perhaps more than any other psychoacousticians, have succeeded in applying their research for the common good. Those who have benefited from this translation of basic research include users of hearing aids and of auditory warnings. I will describe the results of recent experiments aimed at improving hearing by another group, namely users of cochlear and auditory brainstem implants. These include attempts to exploit the polarity sensitivity of the electrically stimulated auditory system in order to extend the ranges of pitch that can be conveyed by each type of implant.
    No preview · Article · Apr 2014 · The Journal of the Acoustical Society of America
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Many natural sounds fluctuate over time. The detectability of sounds in a sequence can be reduced by prior stimulation in a process known as forward masking. Forward masking is thought to reflect neural adaptation or neural persistence in the auditory nervous system, but it has been unclear where in the auditory pathway this processing occurs. To address this issue, the present study used a "Huggins pitch" stimulus, the perceptual effects of which depend on central auditory processing. Huggins pitch is an illusory tonal sensation produced when the same noise is presented to the two ears except for a narrow frequency band that is different (decorrelated) between the ears. The pitch sensation depends on the combination of the inputs to the two ears, a process that first occurs at the level of the superior olivary complex in the brainstem. Here it is shown that a Huggins pitch stimulus produces more forward masking in the frequency region of the decorrelation than a noise stimulus identical to the Huggins-pitch stimulus except with perfect correlation between the ears. This stimulus has a peripheral neural representation that is identical to that of the Huggins-pitch stimulus. The results show that processing in, or central to, the superior olivary complex can contribute to forward masking in human listeners.
    Full-text · Article · Sep 2013 · PLoS ONE
  • [Show abstract] [Hide abstract]
    ABSTRACT: People often have to listen to someone speak in the presence of competing voices. Much is known about the acoustic cues used to overcome this challenge, but almost nothing is known about the utility of cues derived from experience with particular voices-cues that may be particularly important for older people and others with impaired hearing. Here, we use a version of the coordinate-response-measure procedure to show that people can exploit knowledge of a highly familiar voice (their spouse's) not only to track it better in the presence of an interfering stranger's voice, but also, crucially, to ignore it so as to comprehend a stranger's voice more effectively. Although performance declines with increasing age when the target voice is novel, there is no decline when the target voice belongs to the listener's spouse. This finding indicates that older listeners can exploit their familiarity with a speaker's voice to mitigate the effects of sensory and cognitive decline.
    No preview · Article · Aug 2013 · Psychological Science

Publication Stats

5k Citations
444.95 Total Impact Points


  • 2002-2015
    • Mrc Harwell
      Oxford, England, United Kingdom
  • 1970-2015
    • MRC Cognition and Brain Sciences Unit
      Cambridge, England, United Kingdom
  • 2014
    • Cambridge Eco
      Cambridge, England, United Kingdom
  • 2013
    • The University of Manchester
      • School of Psychological Sciences
      Manchester, England, United Kingdom
  • 1984-2007
    • University of Cambridge
      • • MRC Cognition and Brain Sciences Unit
      • • Department of Psychology
      Cambridge, ENG, United Kingdom
  • 2004
    • Technische Universiteit Eindhoven
      Eindhoven, North Brabant, Netherlands
  • 2003
    • University of Essex
      • Department of Psychology
      Colchester, England, United Kingdom
  • 1991-1995
    • University of Sussex
      Brighton, England, United Kingdom
  • 1989-1990
    • Northeastern University
      • Department of Communication Sciences & Disorders
      Boston, Massachusetts, United States
  • 1987-1989
    • Park University
      Parkville, Missouri, United States
  • 1987-1988
    • University of Nottingham
      Nottigham, England, United Kingdom