bluuebunny/crossref_metadata_2025 huggingface dataset:
Connectionism and the Learning of Probabilistic Concepts
Authors: Shanks David R.
Published: September 2011

Three experiments examine the claim of Gluck and Bower (1986, 1988a, 1988b) that the learning of medical concepts can be simulated by a connectionist network in which the symptoms are the input and the diagnosis is the output. The first experiment replicates the main finding of Gluck and Bower. In this experiment, subjects were required to estimate the probability of each of two diseases, given a particular target symptom. In fact these two probabilities were identical, but because one illness was more common than the other, the target symptom was a better predictor of the rare disease than of the common disease. Contrary to a normative probability judgement account, subjects were biased in that they judged the probability of the rare disease given the target symptom to be greater than the probability of the common disease given the target symptom. Gluck and Bower argued that such a result was predicted by a connectionist network using the Rescorla-Wagner learning rule, but it is argued that Gluck and Bower's network simulation was not appropriate for the experiment they had performed. In fact, it appeared that the connectionist network failed to predict the bias in the subjects’ probability estimates.

However, this conclusion rests on an assumption that Gluck and Bower implicitly made. They arranged for P(rare disease/target symptom) and P(com-mon disease/target symptom) to be identical across all trials on which the target symptom occurred, both on its own and with other symptoms present. Gluck and Bower assumed that the subjects were estimating these probabilities. But the results of the second experiment showed instead that the subjects were estimating the probability of each disease given only the target symptom. In the final experiment the design was changed so that this problem might be circumvented. In this experiment, again, the subjects were biased in their probability judgements exactly as the connectionist network predicted. Thus, finally, evidence was found which was compatible with the network model but not with a normative account, but this was true only if the network did not include a layer of hidden units.
The Reliability of a Certain University Examination Compared with the Precision of Absolute Judgements
Authors: Laming Donald
Published: September 2011

A formula is proposed to estimate the reliability with which an examination assesses the individual merits of the candidates, using only the marks assigned naturally by the examiners. This formula, which is founded in classical test theory, can be applied (as here) to an examination in which the candidates are offered a wide choice of questions and different questions are marked by different pairs of examiners. The use of the formula is illustrated by reference to a certain university examination; and the results of analysing the correlations between marks independently awarded by different examiners are compared with previous studies of the reliability of university examinations, with similar studies of GCE examinations, and with the precision of absolute judgement of simple stimulus magnitudes.
Autobiographical and Text Recall in the Elderly: An Investigation of a Processing Resource Deficit
Authors: Holland C. A. , Rabbitt P. M. A.
Published: September 2011

This study examined different explanations of age-related impairments in recall of details from text and autobiographical events. An interpretation of Central Executive Capacity Deficit was supported and explored further. This suggests that details are more demanding of capacity than main points, and that ability to appropriately integrate details with context is likely to be impaired. An implication was that irrelevant and false information may occur, and this was supported in both autobiographical and text recall. The effects were then examined in relation to various measures of ability. The aim was to determine whether declining capacity (as indicated by “Fluid Intelligence” measures) predicted ability to recall in a detailed manner. The difficulty with details was predicted independently by chronological age and by measures of fluid (e.g. AH4 intelligence test) and the more crystallized verbal ability (Mill Hill vocabulary test). Only a measure of the specificity of autobiographical recall was predicted solely by measures of fluid intelligence. Decreased specificity was not a result of faster decay of memory for details, as there was little difference across the lifespan. The resource deficit appears to affect retrieval and appropriate implementation of detail. It was concluded that lower-ability elderly subjects have decreased Central Executive resources, which leads to poor (often inappropriate) integration of details with central thematic points, but that subjects' verbal ability, which does not decline with age, still has an important part to play.
On the Representation and Processing of Compound Words: Automatic Access to Constituent Morphemes Does Not Occur
Authors: Sandra Dominiek
Published: September 2011

Three lexical decision experiments using a variant of the semantic priming technique tested the hypothesis that compound words are morphologically decomposed during recognition. If a compound constituent is accessed during processing, an associative prime will facilitate that access and hence recognition of the whole word. Contrary to the predictions derived from the automatic decomposition hypothesis, Experiment 1 revealed no priming effects for semantically opaque compounds (buttercup) and pseudo-compounds (boycott), primed either on their initial or final constituent. The data from Experiment 2 suggested that both constituents in semantically transparent compounds are accessed (teaspoon). Experiment 3 was a replication experiment, confirming that final constituents of opaque compounds are not accessed, whereas those of transparent compounds are. The overall pattern of data refutes the notion of automatic morphological decomposition proposed by Taft and Forster (1976). However, a revised decomposition procedure would be compatible with the results. Morphemes might only be accessed if no other lexical representations match the orthographic description of the parsed stimulus part. In this account, only semantically transparent compounds lack an independent lexical representation.
Episodic Memory in Dementia of the Alzheimer Type and in Normal Ageing: Similar Impairment in Automatic Processing
Authors: Abbenhuis M. A. , Raaijmakers W. G. M. , Raaijmakers J. G. W. , van Woerden G. J. M.
Published: September 2011

A perceptual identification task was used to provide an implicit measure for automatic memory processes. The facilitation of word identification on repeated presentation is taken as a measure of the automatic retrieval of an episode. In addition, recognition memory was tested. The recognition task is an explicit test of memory and relies mainly on controlled processing. In the first experiment 11 patients suffering from probable Alzheimer disease and 11 normal age- and sex-matched controls were tested. Both groups exhibited a rather small facilitation effect (ca 7%) but did not differ in the size of the effect. However, when tested explicitly, a difference in recognition memory existed between the two groups. In the second experiment the performance of 11 normal young subjects was compared to that of 11 normal elderly subjects. Whereas the elderly group showed a small facilitation effect similar to that observed in the first experiment, a considerable facilitation effect was found for the young group. Also, the elderly group had poorer recognition memory than the young group.
Tests of Dual Process Theory: Word Priming and Recognition
Authors: Mandler George , Hamson Carmen Overson , Dorfman Jennifer
Published: September 2011

Dual process theory postulates two representational processes: Activation of a representation makes the mental event more easily and automatically accessible. Elaboration of a mental event produces access to the representation through search and retrieval processes. We explored word priming in recognition and in a stem completion task where the primed word was one of several possible completions for a 3-letter stem. The main hypothesis was that priming has similar and parallel effects in the two tasks. The initial presentation (priming) of items was under conditions of either semantic or non-semantic processing. Priming was either direct, by the presentation of the target word, or indirect, by the presentation of phonologically related (rhyming) or semantically related (categorical) items. When priming occurred, RTs increased from direct to phonologically primed and to semantically primed items for both completion and recognition tests. One additional experiment confirmed the absence of semantic processing in the non-semantic condition, and another experiment showed that when response requirements for recognition and completion responses are equated, RTs to the two tests are comparable.
The Effects of Different Types of Encoding Task on Memory for Famous Faces and Names
Authors: Hanley J. Richard J. , Pearson Norma A. , Howard Louise A.
Published: September 2011

In this study, incidental memory for familiar faces following different types of encoding task was investigated. Subjects who had been asked to name faces of celebrities at presentation subsequently remembered them significantly better than subjects who had been asked to provide contextual information about the faces, and than subjects who had been asked to distinguish them from unfamiliar faces. This effect persisted regardless of whether the tests required memory for names, faces, or biographical information. It is argued that these results can be explained in terms of the face-processing framework of Bruce and Young (1986) and the theory of episodic memory for faces put forward by Bruce (1982, 1988). However the findings are not consistent with levels of processing (Craik & Lockhart, 1972), nor transfer appropriate processing (Morris, Bransford, & Franks, 1977).
Bandwidth Knowledge of Results and Motor Learning: More than Just a Relative Frequency Effect
Authors: Lee Timothy D. , Carnahan Heather
Published: September 2011

Motor learning is facilitated when knowledge of results (KR) is presented in accordance with a goal-centred bandwidth (i.e. when the error exceeds a tolerance limit about a movement goal). However, under different conditions of the bandwidth procedure the frequency with which KR is provided is also affected—the wider the goal-centred tolerance limits, the lower the frequency of KR. Since low-KR frequency conditions also have been shown to facilitate motor learning, it is not known whether the bandwidth KR effect is a unique phenomenon in motor learning or is simply due to differences in the frequency of KR. In the present study we partitioned the effects due to bandwidth KR from the effects due to KR frequency using a yoking procedure. Results from the acquisition performance trials indicated that bandwidth procedures exerted both error reduction and performance stabilization influences on motor behaviour that exceeded the effects of the relative frequency control procedures. Bandwidth procedures further resulted in better performance consistency during retention than the relative frequency conditions. These findings were discussed in terms of how KR about movement error and KR about the correctness of movement affect the learning of motor skill.
Central and Peripheral Precuing of Forced-Choice Discrimination
Authors: Cheal MaryLou , Lyon Don R.
Published: September 2011

There are suggestions in the literature that spatial precuing of attention with peripheral and central cues may be mediated by different mechanisms. To investigate this issue, data from two previous papers were reanalysed to investigate the complete time course of precuing target location with either: (1) a peripheral cue that may draw attention reflexively, or (2) a central, symbolic cue that may require attention to be directed voluntarily. This analysis led to predictions that were tested in another experiment. The main result of this experiment was that a peripheral cue produced its largest effects on discrimination performance within 100 msec, whereas a central cue required approximately 300 msec to achieve maximum effects. In conjunction with previous findings, the present evidence for time differences between the two cuing conditions suggests that more than one process is involved in the spatial precuing of attention.
The Coordination of Bimanual Aiming Movements: Evidence for Progressive Desynchronization
Authors: Fowler Barry , Duck Tom , Mosher Merv , Mathieson B.
Published: September 2011

It is known that when simultaneous bimanual aiming movements are made to targets with different IDs (Index of Difficulty), Fitts' Law is violated. There is massive slowing of the easy target hand, but a debate has arisen over the degree of synchronization between the hands and whether this effect represents a coordinative structure or interference due to neural cross-talk. This issue was investigated in an experiment with 12 subjects who moved styli forward in the sagittal plane to pairs of targets that differed in difficulty (0.77/3.73 ID and 0.77/5.17 ID). Reaction time, movement time, and kinematic measures of resultant velocity and acceleration were analysed. The results showed clear-cut timing differences between the hands that depended on both the ID difference between target pairs and elapsed time of the movement. The violation of Fitts' Law was confined to the easy target hand. Pronounced individual differences in both timing differences and left-right asymmetry were also noted. Neither the coordinative structure nor the neural cross-talk models can fully account for these data, and it is possible that the initial constraints on movement are moderated by visually driven corrective movements.
Short Report: Object-Centred Inhibition of Return of Visual Attention
Authors: Tipper Steven P. , Driver Jon , Weaver Bruce
Published: September 2011

Our response to visual events can be delayed at positions we have recently examined attentively. Such inhibition could organize visual search through static scenes by suppressing those loci already searched, but this mechanism would fail in moving scenes as objects' locations then change during search. We cued attention to a moving object and found subsequent inhibition at the locus the object later occupied. This implies that previously examined objects are suppressed. Such object-centred inhibition would be highly adaptive, but would require a sophisticated neural implementation for a mechanism held to be sub-cortical.
Spectral, Intensive, and Temporal Factors Influencing Overshoot
Authors: Bacon Sid P. , Smith Michael A.
Published: September 2011

Threshold was measured for a 10-msec, 4.0-kHz signal presented near the onset or in the temporal centre of a 400-msec noise masker. Overshoot, the difference (in dB) between these two thresholds, was seen only for masker bandwidths wider than a critical band. The threshold near masker onset, and hence overshoot, could be reduced by the presence of an additional noise that was presented continuously or gated on and off prior to masker onset. The spectral, intensive, and temporal properties of this effect were studied. When the additional noise was continuous and either bandpass filtered with a variable bandwidth or notch filtered with a variable notchwidth, the results indicated that energy both near and remote from the signal frequency contributed to the reduction in overshoot. The effect of this additional noise was highly dependent upon its relative level. When the additional noise was 400 msec in duration and the delay between its offset and the onset of the masker was varied, overshoot “recovered” to its maximum value within about 50 msec. Finally, as the duration of the additional noise was varied from 3 to 400 msec while the time between its offset and masker onset was fixed, the reduction in overshoot was virtually complete for durations of about 25–50 msec. The results are consistent with the notion that overshoot at least partly reflects peripheral adaptation, and that this adaptation is not restricted to the signal frequency channel but, rather, extends in both directions over several channels.
Spectral Weights and the Profile Bowl
Authors: Green David M. , Berg Bruce G.
Published: September 2011

In these experiments, listeners detected changes in the shape of a complex spectrum that varied in overall level. With multicomponent complexes, a typical finding is that the listeners were more sensitive to changes made in the middle components of the spectrum than to changes made at either edge. We used a technique developed by Berg (1989) to estimate the weight listeners attached to the different components of the spectrum in making these judgements. For reasons not understood, the pattern of spectral weights was nearly optimum for a change made in the middle component of the spectrum and much poorer when the change occurred at either edge.
The Detection of a Tone Added to a Narrow Band of Noise: The Energy Model Revisited
Authors: Richards Virginia M. , Heller Laurie M. , Green David M.
Published: September 2011

In an effort to determine whether cues related to changes in energy contribute to the detection of a tone added to a narrow band of noise, we examined the effect of level variation on detection thresholds. In the first experiment, the level of each waveform was randomly varied on each presentation. Level variation had only marginal effects on performance. In addition, detection thresholds were obtained using bands of noise with equal energy across intervals. Neither increasing nor decreasing the variance of the noise-alone and tone-plus-noise energy difference distributions altered the detectability of a tone added to noise. Thus, the changes in energy that are concomitant with the addition of the tone are not the sole cue for the detection of the tone. In a second experiment, three psychometric functions were measured. One function was determined using no level variation, one was measured in the presence of level variation, and one was measured in the context of level variation, but for trials without level variation. The context of level variation slightly reduced detectability. In a third experiment, we compared detectability in three conditions: no level variation, across-trial level variation, and across-interval level variation. The thresholds obtained in the absence of level variation were superior to those measured in the presence of level variation, regardless of the manner in which the level variation was incorporated.
A Computer Model of Auditory Stream Segregation
Authors: Beauvois Michael W. , Meddis Ray
Published: September 2011

A computer model is described which simulates some aspects of auditory stream segregation. The model emphasizes the explanatory power of simple physiological principles operating at a peripheral rather than a central level. The model consists of a multi-channel bandpass-filter bank with a “noisy” output and an attentional mechanism that responds selectively to the channel with the greatest activity. A “leaky integration” principle allows channel excitation to accumulate and dissipate over time. The model produces similar results to two experimental demonstrations of streaming phenomena, which are presented in detail. These results are discussed in terms of the “emergent properties” of a system governed by simple physiological principles. As such the model is contrasted with higher-level Gestalt explanations of the same phenomena while accepting that they may constitute complementary kinds of explanation.
Vowel and Consonant Recognition with the Aid of a Multichannel Cochlear Implant
Authors: Dorman Michael F. , Dankowski Korine , McCandless Geary , Parkin James L. , Smith Luther
Published: September 2011

In this report we review the vowel and consonant recognition ability of patients who use a multichannel cochlear implant and who achieve relatively good word identification scores. The results suggest that vowel recognition is accomplished by good resolution of the frequency of the first formant (F1) combined with poor resolution of the frequency of the second formant (F2). The results also suggest that consonant recognition is accomplished (1) by using information from the amplitude envelope, including periodicity/aperiodicity, as cues to manner and voicing, (2) by using F1 as an aid to the identification of manner and voicing, and (3) by using information from cochlear place of stimulation to provide a very crude indication of the shape of the frequency spectrum above 1kHz.
Single Band Amplitude Envelope Cues as an Aid to Speechreading
Authors: Grant Ken W. , Braida Louis D. , Renn Rebecca J.
Published: September 2011

Amplitude envelopes derived from speech have been shown to facilitate speech-reading to varying degrees, depending on how the envelope signals were extracted and presented and on the amount of training given to the subjects. In this study, three parameters related to envelope extraction and presentation were examined using both easy and difficult sentence materials: (1) the bandwidth and centre frequency of the filtered speech signal used to obtain the envelope; (2) the bandwidth of the envelope signal determined by the lowpass filter cutoff frequency used to “smooth” the envelope fluctuations; and (3) the carrier signal used to convey the envelope cues. Results for normal hearing subjects following a brief visual and auditory-visual familiarization/training period showed that (1) the envelope derived from wideband speech does not provide the greatest benefit to speechreading when compared to envelopes derived from selected octave bands of speech; (2) as the bandwidth centred around the carrier frequency increased from 12.5 to 1600 Hz, auditory-visual (AV) performance obtained with difficult sentence materials improved, especially for envelopes derived from high-frequency speech energy; (3) envelope bandwidths below 25 Hz resulted in AV scores that were sometimes equal to or worse than speechreading alone; (4) for each filtering condition tested, there was at least one bandwidth and carrier condition that produced AV scores that were significantly greater than speech-reading alone; (5) low-frequency carriers were better than high-frequency or wideband carriers for envelopes derived from an octave band of speech centred at 500 Hz; and (6) low-frequency carriers were worse than high-frequency or wideband carriers for envelopes derived from an octave band centred at 3150 Hz. These results suggest that amplitude envelope cues can provide a substantial benefit to speechreading for both easy and difficult sentence materials, but that frequency transposition of these signals to regions remote from their “natural” spectral locations may result in reduced performance.
A Further Examination of Attentional Effects in the Phonemic Restoration Illusion
Authors: Samuel Arthur G.
Published: September 2011

Models of how listeners understand speech must specify the types of representations that are computed, the nature of the flow of information, and the control structures that modify performance. Three experiments are reported that focus on the control processes in speech perception. Subjects in the experiments tried to discriminate stimuli in which a phoneme had been replaced with white noise from stimuli in which white noise was merely superimposed on a phoneme. In the first two experiments, subjects practiced the discrimination for thousands of trials but did not improve, suggesting that they have poor access to low-level representations of the speech signal. In the third experiment, each (auditory) stimulus was preceded by a visual cue that could potentially be used to focus attention in order to enhance performance. Only subjects who received information about both the identity of the impending word and the identity of the critical phoneme showed enhanced discrimination. Other cues, including syllabic plus phonemic information, were ineffective. The results indicate that attentional control of processing is difficult but possible, and that lexical representations play a central role in the allocation of attention.
The Effects of Flicker on Eye Movement Control
Authors: Kennedy Alan , Murray Wayne S.
Published: September 2011

Groups of typists with extensive experience of screen-based editing and groups of students with no such experience carried out a reading task under three conditions of illumination (50-Hz flicker, 100-Hz flicker, and steady illumination). Subjects read a sentence, which was followed by the presentation of a single stimulus word on the same line to the right-hand side of the display. The task was to decide whether or not the stimulus was present in the sentence. Subjects were free to re-inspect the sentence when making the decision. Eye movements were measured as subjects completed the task. In comparison with students, typists adopted a more cautious reading style, making more right-to-left saccades, shorter saccades, and more corrective eye movements. Flicker affected the performance of both groups of subjects in the first pass, leading to shorter saccades. In the second pass, its effect for students was to shorten the extent of large saccades made to check the presence of the stimulus word. In the group of typists, flicker led to an increase in the variability of saccade extent and a doubling in the number of small corrective saccades. The results are consistent with the view that flicker has two distinct effects on reading, both of which are potentially disruptive. The first relates to an increase in the number of prematurely triggered saccades, which are, as a result, less accurate. The second is an increase in the number of saccades perturbed in flight, which land short of their intended target. These two mechanisms may have different consequences for readers, depending on their reading style.
Phonological Short-term Memory and the Learning of Novel Words: The Effect of Phonological Similarity and Item Length
Authors: Papagno C. , Vallar G.
Published: September 2011

The investigation of a patient with a selective impairment of phonological short-term memory has recently provided evidence that this system may be involved in long-term learning of novel words, for which a pre-existing semantic representation is not available (Baddeley, Papagno, & Vallar, 1988). The present series of experiments in normal subjects explored this hypothesis. We assessed the effects of phonological similarity and item length, which reflect the operation of the phonological short-term store and the rehearsal component of verbal memory, upon paired associate long-term learning of auditorily presented words and non-words. Phonological similarity affected the learning of novel words more than known words (Experiment 1); when a delay was interposed between presentation and recall, the disruptive effect was confined to novel words (Experiment 2). Also word length disrupted the learning of novel words, but not of known words (Experiment 3). These results tie in with neuropsychological evidence to suggest a role for phonological short-term memory in the learning of new words, and they have developmental implications for the study of language acquisition.
Effects of Alcohol, Practice, and Task Complexity on Reaction Time Distributions
Authors: Maylor E. A. , Rabbitt P. M. A. , James G. H. , Kerr S. A.
Published: September 2011

The effects of alcohol (1.0 ml/kg body weight) and practice (2 sessions) were investigated in 2-, 4-, and 8-choice reaction time (RT) tasks with 24 male subjects. The number of errors increased with alcohol, practice, and increasing task complexity (choice). Mean RT decreased with practice, but increased with alcohol and complexity. Both the alcohol and practice effects on mean RT increased as complexity increased. The effects of alcohol, practice, and complexity were all larger for the higher percentiles of the RT distributions than for the lower percentiles. RT distributions were further analysed at each level of choice by plotting percentiles (5th, 10th, …, 95th) for alcohol conditions against corresponding percentiles for no-alcohol conditions, and percentiles obtained early in practice (Session 1) against those obtained later in practice (Session 2). These plots revealed that whereas at all levels of choice the effect of alcohol could be expressed as a simple linear transformation of all RTs, the effect of practice required a more complex curvilinear transformation. Thus, alcohol produces a general slowing of all RTs, whereas practice produces a disproportionate improvement at the slower end of the RT distribution.
Orientational Effects and Component Processes in Symmetry Detection
Authors: Wagemans Johan , Van Gool Luc , d'Ydewalle Géry
Published: September 2011

In previous research on symmetry detection, factors contributing to orientational effects (axis and virtual lines connecting symmetrically positioned dots) and component processes (axis selection and pointwise evaluation) have always been confounded. The reason is the restriction to bilateral symmetry (BS), with pointwise correspondences being orthogonal to the axis of symmetry. In our experiments, subjects had to discriminate random dot patterns from symmetries defined by combining 12 axis orientations (every 15°) with seven reflection angles (0°, yielding BS, and three clockwise and counterclockwise 15° steps, yielding skewed symmetry, SS). In Experiment 1, with completely randomized trial order, a significant interaction between axis and skewing angle was obtained, indicating that classically observed orientational effects are restricted to BS and that the orientation of the pointwise correspondences is important. These basic findings were replicated in three subsequent experiments, which differed in that they used blocks containing patterns with the same axis (Experiment 2), virtual lines orientation (Experiment 3), or their combination (Experiment 4). Based on a comparison between the results obtained by these manipulations, we suggest a possible reason for the failure of preattentive symmetry detection in the case of dot patterns with SS.
On the Relation between Visual Spatial Attention and Visual Field Asymmetries
Authors: Mondor T. A , Bryden M.P.
Published: September 2011

In the typical visual laterality experiment, words and letters are more rapidly and accurately identified in the right visual field than in the left. However, while such studies usually control fixation, the deployment of visual attention is rarely restricted. The present studies investigated the influence of visual attention on the visual field asymmetries normally observed in single-letter identification and lexical decision tasks. Attention was controlled using a peripheral cue that provided advance knowledge of the location of the forthcoming stimulus. The time period between the onset of the cue and the onset of the stimulus (Stimulus Onset Asynchrony—SOA) was varied, such that the time available for attention to focus upon the location was controlled. At short SO As a right visual field advantage for identifying single letters and for making lexical decisions was apparent. However, at longer SOAs letters and words presented in the two visual fields were identified equally well. It is concluded that visual field advantages arise from an interaction of attentional and structural factors and that the attentional component in visual field asymmetries must be controlled in order to approximate more closely a true assessment of the relative functional capabilities of the right and left cerebral hemispheres.
Contextual Interference in Motor Learning: Dissociated Effects Due to the Nature of Task Variations
Authors: Lee Timothy D. , Wulf Gabriele , Schmidt Richard A.
Published: September 2011

The contextual interference effect in motor learning refers to the interference that results from practising a task within the concept of other tasks in a practice session. Several studies have shown that practice under conditions of high contextual interference (i.e. with a random practice order) degrades performance during acquisition trials, compared to low contextual interference conditions (i.e. with a blocked order, where practice is completed on one task before practice on another task is undertaken). In contrast to acquisition performance, random practice usually leads to more effective learning than blocked practice, as measured by retention and transfer tests. One of the hypotheses regarding the effect suggests that a random practice schedule induces more extensive planning operations during practice than a blocked practice condition. If so, then differences between these two conditions should emerge to the degree that the set of tasks requires complete reconstruction of these planning operations on each trial. To address this issue, we compared four groups of subjects: a blocked and random group that practised three timing tasks that shared a common characteristic (same relative timing), and a blocked and random group that practised three tasks that each had different relative timing structures. Subjects practised these tasks on each of two days, with a retention test and two transfer tests that required either a relative timing structure that had been practised previously or had not previously been practised. No random/ blocked differences occurred regardless of the relative timing of the patterns during acquisition or retention. However, for both transfer tests, random practice enhanced learning only for the group that had practised with tasks that each had different relative timing during acquisition. Implications of these results for an explanation of contextual interference are discussed.
Privileged Access by Irrelevant Speech to Short-term Memory: The Role of Changing State
Authors: Jones Dylan , Madden Clare , Miles Chris
Published: September 2011

Memory for visually presented items is impaired by speech that is played as an irrelevant background. The paper presents the view that changing state of the auditory material is an important prerequisite for this disruption. Four experiments studied the effects of sounds varying in complexity in an attempt to establish which features of changing state in the auditory signal lead to diminished recall. Simple unvarying or repetitive speech sounds were not sufficient to induce the irrelevant speech effect (Experiment 1): in addition, simple analogues of speech, possessing regular or irregular envelopes and using a range of carriers, failed to imitate the action of speech (Experiment 2). Variability of between-utterance phonology in the irrelevant stream (Experiment 3) emerged as a crucial factor. Moreover, predictability of the syllable sequence did not reduce the degree of disruption (Experiment 4) suggesting that supra-syllabic characteristics of the speech are of little importance. The results broadly support the idea that disruption of short-term memory only occurs when the speech stream changes in state. It is argued that disruption occurs in memory when cues to serial order based on phonological representations of heard material interfere with the phonological codes of visual origin. It is suggested that cues to changing state of the speech input contaminate those associated with items of visual origin, which are already in a phonological store.
Pseudohomophone Naming and the Word Frequency Effect
Authors: Taft Marcus , Russell Bruce
Published: September 2011

An experiment by McCann and Besner (1987) suggested that non-words that are homophonic with a high-frequency word (e.g. “keap”) are named in the same amount of time as non-words that are homophonic with a low-frequency word (e.g. “fome”), despite such pseudohomophones being faster to name than non-pseudohomophones (e.g. “feap”, “yome”). Such a result is a challenge to any model of lexical processing that places the word-frequency effect at the stage when the word is being selected from amongst all lexical entries. McCann and Besner propose a complex alternative account where frequency effects arise at a later stage of processing, a stage that is not involved in the naming of pseudohomophones. The purpose of the present study is to look for a frequency effect in the naming of pseudohomophones, controlling for orthographic factors that McCann and Besner ignored. The first experiment, using a homophone decision task, establishes a set of items that produce a clear frequency effect. These items are then used in a naming experiment which also reveals a clear frequency effect for those subjects who make use of a lexical route when pronouncing pseudohomophones. It is concluded from this that the complex model developed by McCann and Besner is unnecessary.
The Spontaneous Use of Propositional Connectives
Authors: Byrne Ruth M. J. , Johnson-Laird P. N.
Published: September 2011

We extend the model theory of reasoning to the understanding and use of propositional connectives, such as and, or, and if. We use a novel paraphrase paradigm to compare the model theory to an alternative one based on rules of inference. In Experiment 1, subjects paraphrased pairs of conditionals. Their general knowledge guided their combination of the antecedents: they used disjunctive descriptions to combine antecedents that were each sufficient to bring about the outcome, and they used conjunctive descriptions to combine antecedents that were both necessary to bring about the outcome. They expressed their combinations using simple connectives such as and or or, as the model theory predicts, rather than hypothetical connectives, such as and if or or if, as the rule theory predicts. Experiment 2 demonstrated the phenomenon in the less constrained task of combining three assertions in a single conditional. Conjunctions and disjunctions are easy to elicit; conditionals have proved far more difficult. The model theory proposes that individuals represent a conditional situation by keeping in mind the described events, but they also keep in mind that there may be alternatives to the events. Therefore, they should use conditionals when they are aware that the events may or may not occur. Experiment 3 corroborated this prediction: subjects used conditionals to combine assertions (with no restrictions on the connective they should use) when the clause describing the outcome contained a modal verb that suggested that the outcome might or might not occur.
Do Abrupt-onset Peripheral Cues Attract Attention Automatically?
Authors: Tepin Michael B. , Dark Veronica J.
Published: September 2011

The proportion of peripheral cues that predicted at which of two locations a discrimination target would occur was manipulated in three experiments. Near cues occurred adjacent to the target and far cues occurred adjacent to the other location. In Experiment 1, near and far cues were presented in separate blocks so each predicted target location. Both types of cue produced benefit relative to a neutral baseline. In Experiment 2 expectancy for near versus far cues was manipulated. In one group, 80% of the peripheral cues were near; in another, only 20% were near; in a third, near and far cues occurred randomly. Near cues always produced benefit. Far cues produced benefit when they were expected, had no effect in the random group, and sometimes produced cost when they were unexpected. Experiment 3 repeated the near-expected and far-expected conditions, but target duration was shortened to 50 msec. A similar pattern emerged, except that near cues produced less benefit at longer SOAs when they were unexpected. The data suggest that peripheral, abrupt-onset cues may produce benefit via an automatic process, but that such a process is more like location priming than the capture of attention. Expectancy determines whether and where attentional resources will be allocated in response to the cue.
Saccadic Eye Movements in Parkinson's Disease: I. Delayed Saccades
Authors: Lueck C. J. , Tanyeri S. , Crawford T. J. , Henderson L. , Kennard C.
Published: September 2011

The saccadic eye movements of nine patients with Parkinson's disease were compared to those of nine age-matched controls in two paradigms generating volitional saccades. In both paradigms, subjects had to make delayed saccades to peripheral LED targets: a peripheral target appeared 700 msec before a buzzer sounded, the buzzer being the signal to make a saccade to the target. In the first paradigm (“centre-off”), the fixation target was extinguished simultaneously with buzzer onset. In the second (“centre-remain”) it was not extinguished until 1000 msec later. The results showed that for outward saccades in both paradigms, there was no difference between Parkinsonian patients and controls, but saccadic latencies were significantly shorter in the “centre-remain” paradigm. The initial outward saccades were indistinguishable from the normal, reflex saccades of the same subjects. However, saccades returning to the centre (a type of remembered target saccade) were hypometric and showed multistepping. Both effects were more pronounced in patients with Parkinson's disease. The significance of these findings in terms of current hypotheses about the nature of the Parkinsonian saccadic deficit is discussed.
Semantic Processing of Foveally and Parafoveally Presented Words in a Lexical Decision Task
Authors: Fuentes Luis J. , Tudela Pío
Published: September 2011

Using a lexical decision task in which two primes appeared simultaneously in the visual field for 150 msec followed by a target word, two experiments examined semantic priming from attended and unattended primes as a function of both the separation between the primes in the visual field and the prime-target stimulus-onset asynchrony (SOA). In the first experiment significant priming effects were found for both the attended and unattended prime words, though the effect was much greater for the attended words. In addition, and also for both attention conditions, priming showed a tendency to increase with increasing eccentricity (2.3°, 3.3°, and 4.3°) between the prime words in the visual field at the long (550 and 850 msec) but not at the short (250 msec) prime-target SOA. In the second experiment the prime stimuli were either two words (W-W) or one word and five Xs (W-X). We manipulated the degree of eccentricity (2° and 3.6°) between the prime stimuli and used a prime-target SOA of 850 msec. Again significant priming was found for both the attended and unattended words but only the W-W condition showed a decrement in priming as a function of the separation between the primes; this decrement came to produce negative priming for the unattended word at the narrow (2°) separation. These results are discussed in relation to the semantic processing of parafoveal words and the inhibitory effects of focused attention.
A Dynamical Systems Approach to Skill Acquisition
Authors: Vereijken B. , Whiting H. T. A. , Beek W. J.
Published: September 2011

This paper argues that the answer to the question, what has to be learned, needs to be established before the question, how is it learned, can be meaningfully addressed. Based on this conviction, some of the limitations of current and past research on skill acquisition are discussed. Motivated by the dynamical systems approach, the question of “what has to be learned” was tackled by setting up a non-linear mathematical model of the task (i.e. learning to make sideways movements on a ski apparatus). On the basis of this model, the phase lag between movements of the platform of the apparatus and the actions of the subject was isolated as an ensemble variable reflecting the timing of the subject in relation to the dynamics of the apparatus. This variable was subsequently used to study “how” the task was learned in a discovery learning experiment, in which predictions stemming from the model were tested and confirmed. Overall, these findings provided support for the hypothesis, formulated by Bernstein (1967), that one of the important effects of practice is learning to make use of reactive forces, thereby reducing the need for active muscular forces.

In addition, the data from a previous learning experiment on the ski apparatus—the results of which had been equivocal—were reconsidered. The use of phase lag as a dependent variable provided a resolution of those findings.

On the basis of the confirmatory testing of predictions stemming from the model and the clarification of findings from a previous experiment, it is argued that the dynamical systems approach put forward here provides a powerful method for pursuing issues in skill acquisition. Suggestions are made as to how this approach can be used to systematically pursue the questions that arise as a natural outcome of the experimental evidence presented here.
Human Reasoning: Deduction Rules or Mental Models, or Both?
Authors: Roberts Maxwell J.
Published: September 2011

A good deal of energy is currently being expended into discovering the fundamental machinery underlying deductive reasoning. Is it based upon mental models (arrays) or deduction rules (propositions)? The appeal of finding a “grand unified theory” of reasoning is obvious, but the likelihood of achieving this must also be considered.

This paper discusses the use of experimental psychology in attempts to discover the processes associated with the fundamental reasoning mechanism. One particular problem is that individuals can use different strategies to solve reasoning problems. The consequences of this are assessed in relation to: (1) the assumptions underlying the experiments, (2) the choice of tasks and task presentations intended to enable the fundamental reasoning processes to be viewed directly, and (3) the power status of the theories and the nature of the evidence required to show that either theory is superior. Under close scrutiny the debate appears to be unresolvable by using empirical techniques. However, although the main conclusions are negative, it is suggested that approaches that directly investigate individual differences are likely to be useful alternatives.
Evoking the Permission Schema: The Impact of Explicit Negation and a Violation-Checking Context
Authors: Kroger James K. , Cheng Patricia W. , Holyoak Keith J.
Published: September 2011

Cheng and Holyoak (1985) proposed that realistic reasoning in deontic contexts is based on pragmatic schemas such as those for assessing compliance with or violation of permission and obligation rules, and that the evocation of these schemas can facilitate performance in Wason's (1966) selection task. The inferential rules in such schemas are intermediate in generality between the content-independent rules proposed by logicians and specific cases stored in memory. In one test of their theory, Cheng and Holyoak demonstrated that facilitation could be obtained even for an abstract permission rule that is devoid of concrete thematic content. Jackson and Griggs (1990) argued on the basis of several experiments that such facilitation is not due to evocation of a permission schema, but, rather, results from a combination of presentation factors: the presence of explicit negatives in the statement of cases and the presence of a violation-checking context. Their conclusion calls into question both the generality of content effects in reasoning and the explanation of these effects. We note that Jackson and Griggs did not test whether the same combination of presentation factors would produce facilitation for an arbitrary rule that does not involve deontic concepts, as their proposal would predict. The present study tested this prediction. Moreover, we extended Jackson and Griggs’ comparisons between performance with an abstract permission rule versus an arbitrary rule, introducing clarifications in the statement of each. No facilitation was observed for an arbitrary rule even when explicit negatives and a violation-checking context were used, whereas strong facilitation was found for the abstract permission rule under the same conditions. Performance on the arbitrary rule was not improved even when the instructions indicated that the rule was conditional rather than biconditional. In contrast, a small but reliable degree of facilitation was obtained for the abstract permission rule, with violation-checking content even in the absence of explicit negatives. The theory of pragmatic reasoning schemas can account for both the present findings and those reported by Jackson and Griggs.