bluuebunny/crossref_metadata_2025 huggingface dataset:
US policy in the Horn of Africa: aboulia or proxy intervention?
Authors: Halliday Fred
Published: July 2007

Among the many questions raised by the dramatic events in the Horn of Africa none is more important or more misunderstood than that of the role played by the USA, and by its various Middle Eastern allies, in the region. The Carter Administration claims that it has avoided direct involvement in the conflicts and has berated the Soviet Union and Cuba for their intervention on the side of Ethiopia. By contrast, the Ethiopian government has stressed the links between the Somali invasion of Ogaden and the various opposition forces inside Ethiopia on one side and the USA, and the rightwing Arab states, on the other. What has been the role of the USA and its Middle Eastern clients in the disputes of the Horn? And how has US policy evolved in recent years? These are the questions which the following analysis will try, in a preliminary manner, to answer.
Class, race and gender: domestic workers in South Africa
Authors: Gaitskell Deborah , Kimble Judy , Maconachie Moira , Unterhalter Elaine
Published: July 2007

Domestic service has long been a major sector of the South African labour market, for black women particularly, but the government has only lately begun to consider stipulating minimum employment conditions in this sphere. Union formation among domestic workers on any significant scale is also only a recent phenomenon. This article takes a preliminary look at domestic service from various angles — conceptual, historical and contemporary. A new slant is provided on the existing theoretical discussion of domestic labour, for domestic workers are here clearly distinguished from housewives. The peculiar way in which race, class and gender have all shaped the character of domestic service in South Africa is stressed at the outset, and the way various races and both sexes moved into and sometimes out of domestic service is illustrated. The authors conclude that the current trend away from the long‐established pattern of live‐in servants may well aid political mobilisation of formerly isolated domestic workers.
The forgotten agenda in Somalia
Authors: Predergast John
Published: July 2007

This Briefing describes the withdrawal of international peacekeeping forces from Somalia on 31 May 1994 and provides useful insights into the real nature and dangers of ignoring the fundamental issues of human rights and, central to this whole debate, control of resources, principally land. It warns against the resurrection of militia attacks not only against each other but the population at large. Prendergast's solution is a continuity, though different, by the UN (which costs roughly $310 million per year). Other critics of the UN role have suggested that a better solution would be withdrawal. ROAPE is interested in continuing this debate and welcomes comment.
The Role of Attention in the Disinhibition of Displacement Activities
Authors: McFarland D. J.
Published: July 2007

A mechanism for the disinhibition of displacement activities is proposed, by which a factor arising from non-reward causes attention to be switched to irrelevant aspects of the stimulus situation. In addition to evidence already extant, three lines of evidence are presented for the case of displacement pecking in the Barbary dove: (1) partially rewarded doves learn more about incidental aspects of a discrimination situation than consistently rewarded doves; (2) partially rewarded doves respond more readily to irrelevant stimuli than consistently rewarded doves; (3) doves which take longest to extinguish a simple approach response, also spend most time displacement pecking.
Susceptibility to the Müller-Lyer Illusion and its Relationship to Differences in Size Constancy
Authors: Hamilton Vernon
Published: July 2007

The hypothesis that susceptibility to the Müller-Lyer illusion is the result of normal constancy scaling, misapplied, was submitted to direct test. No significant correlations between illusion error and size constancy estimates were obtained. Also invalidated were hypotheses that under-constancy is correlated with non-susceptibility to the illusion, and that over-constancy is correlated with greater illusion error. The results suggest that an approach to the explanation of illusion effects by means of analysing individual differences in size constancy, in intelligence and preferred “perceptual style,” might be fruitful. Some tentative suggestions are made concerning the role of perceptual inference, abstraction and analysing.
The Effect of Grip-Tension on Tactile-Kinaesthetic Judgement of Width
Authors: Evans G. Burn , Howarth Edgar
Published: July 2007

The effect of various grip-tensions on the accuracy of kinaesthetic width judgements was tested. Forty first-year psychology students were used as subjects. Significant differences in accuracy between pressures were found in the descending adjustments with greatest accuracy at 1.0 kg. Some significant differences were found between pressures in ascending adjustments. All subjects overestimated on the descending and underestimated on the ascending trials at all pressure levels. Increased grip-tension was found to reduce the accuracy of width judgement in terms of constant error while affecting varlance only slightly.
Observing Responses and Uncertainty Reduction
Authors: Steiner J.
Published: July 2007

Rhesus monkeys and baboons were placed in an observing response situation where on any trial they could work for food in the presence of an imposed stimulus or make an observing response by pressing a lever to present an alternative stimulus. The reinforcing properties of the alternative stimulus were assessed by placing the observing response on a progressive ratio schedule and were found to vary as a function of the difficulty of the imposed discrimination and the degree to which the imposed discrimination had been learned. The results are consistent with the hypothesis that the reinforcing strength of the alternative stimuli varies with the amount of uncertainty they reduce. Eliminating the response requirement showed that the effect was not simply due to the fact that informative stimuli permitted a saving of responses.
The Distance Gradient in the After-Effect of Kinaesthetic Width Judgement
Authors: Pressey A. W.
Published: July 2007

The combined effects of inspection-time and interfigural distance on a kinaesthetic figural after-effect were determined. The figural after-effect was defined as the degree to which a 2-in. width appeared to shrink following prolonged inspection of larger widths. The inspection-widths were 2.0, 2.5, 3.0, 3.5, 4.0, and 4.5 in. and the inspection-times were 10 and 50 sec. A control group which did not inspect any widths was also employed. 156 subjects were tested. The results indicated that the classical non-monotonic relationship between interfigural distance and figural after-effect was not present. Instead, the figural after-effect increased as a negatively accelerated function of interfigural distance. Increasing inspection-time increased the asymptotic level of the figural after-effect. These results were interpreted in terms of the effects of anchors on judgements of magnitude.
Apparatus Accurate Delays for Auditory Feedback Experiments
Authors: Huggins A. W. F.
Published: July 2007

This note describes a way of modifying a tape recorder for producing accurately controllable delays for experiments with delayed auditory feedback. Any value of delay from 80 millisec. to 1.2 sec. can be obtained to the nearest millisec., and the range could be extended by some minor changes. The delay is continuously monitored on a digital electronic timer.
Rehearsal Grouping and Hierarchical Organization of Serial Position Cues in Short-Term Memory
Authors: Wickelgren Wayne A.
Published: July 2007

Lists of 8, 9, or 10 digits were presented at the rate of 1 digit/sec. to subjects instructed to rehearse silently the digits in non-overlapping groups of 1, 2, 3, 4, or 5 digits, after hearing each digit. Subjects were instructed not to rehearse any digits outside the group currently being presented. Rehearsing in 3's was optimal, irrespective of list length. Both recall of items and recall of the correct positions of items improved from 1's to 2's to 3's. Recall of items declined very little from 3's to 4's to 5's, but recall of position declined sharply. Errors in positioning digits tended, above chance, to be in the same group or the same position in a different group. The results suggest that both item-to-item associations and serial position-to-item associations are formed in short-term memory, that only two or three serial position cues are used, but that these serial position cues can be hierarchically organized into a beginning, middle, and end group and a beginning, middle, and end position within a group.
Short-Term Memory as a Function of Input Modality
Authors: Margrain Susan A.
Published: July 2007

The two experiments reported are concerned with short-term memory for digit lists simultaneously presented both auditorily and visually. Results showed (1) that interpolated written and verbal recall differentially affect retention depending on whether the to-be-recalled list was presented auditorily or visually. (2) That input modality appears to be far more important for recall than was directing subjects' attention to a list during input, when that list might or might not have been subsequently required for recall. The results suggest that short-term storage is modality specific. In this case, Broadbent's P and S mechanisms do not adequately describe what happens during simultaneous visual and auditory presentation. Nor would Sperling's suggestion of a final auditory store appear to be supported.
Sequential Effects in a Two-Choice Serial Reaction Task
Authors: Hale D. J.
Published: July 2007

Twenty-four subjects performed a symbolic two-choice serial reaction task under four conditions. These were with a delay from previous response to onset of next stimulus of 100 millisec, 600 millisec., 2 sec., and a fourth condition of 2 sec. delay with verbal prediction of the next stimulus. A positive recency or repetition effect occurred at 100 millisec. delay where RTs to repeated stimuli were faster than RTs to alternate stimuli. At 600 millisec. this effect was still present, though much reduced. The 2 sec. delay gave a negative recency effect where RTs were slower to repeated than to alternate stimuli. This effect increased significantly with simultaneous prediction of the next stimulus. The verbal predictions themselves displayed negative recency. Run analysis of the four conditions revealed striking differences. These results emphasize the need for analysing the microstructure of choice RT situations and reveal deficiencies in present models.
Frustration, Preference and Behavioural Contrast
Authors: Bloomfield T. M.
Published: July 2007

Pigeons' pecks on both a red (left-hand) and a striped (right-hand) response key were reinforced on a concurrent variable-interval 2-min. schedule until the proportion of responses given to each key had stabilized. In alternate sessions, the right-hand key was covered, while responding to a green stimulus on the left-hand key was reinforced on variable-interval 1-min. When responding to green was later extinguished, more responses were made to the striped key in reinforcement sessions, although the rate of responding to the other, red key increased. Replacing extinction during green by reinforcement returned the preference and the response rates to their previous levels. These results are compared with a previous experiment in which the striped key was not present, where a similar increase in response rate to red was observed after extinction on green. The shift in preference coupled with the usual contrast effect in the present experiment supports an interpretation of behavioural contrast in terms of the frustrative effects of extinction.
Effects of Response Pacing on Conditioned Suppression
Authors: Blackman Derek
Published: July 2007

In this experiment, which employed a balanced design with two rat subjects, the frequency of reinforcement remained constant while the rate of operant responding was varied by means of a response pacing technique. At each of three response rates, 1-min. periods of noise were presented, and, as these periods ended, a slight unavoidable shock was delivered to the rat. This procedure resulted in suppression of the operant responding during the periods of noise. This behavioural change was measured by a suppression ratio, essentially a comparison of the response rates in the presence and absence of the noise. The suppression ratios varied in a systematic way during the experiment, denoting most conditioned suppression when the baseline rate of responding was high, and least suppression when this was low. It is therefore concluded that response rate in one factor determining the degree of conditioned suppression in this controlled experiment. The conclusion is corroborated by absolute measures of responding during the pre-shock periods of noise.
Reversal of the Müller-Lyer Illusion with Changes in the Length of the Inter-Fins Line
Authors: Fellows Brian J.
Published: July 2007

Subjects were asked to judge the relative lengths of lines placed between the ingoing and the outgoing fins of a Müller-Lyer figure. It was found that with the gap between the fins constant at 160 mm. there was a reversal of the normal Müller-Lyer illusion when the inter-fins line was between 40 and 100 mm. long. This effect was maximal when the line was 80 mm. The normal illusion returned when the line was increased in length to 120 mm. These findings do not support Gregory's inappropriate constancy scaling theory. They seem to suggest the operation of two distinct illusory forces in the Müller-Lyer situation. The reverse illusion may be due to the greater expansion effect upon the line between the ingoing fins, caused by the greater “enclosing” nature of these fins.
The Effects of Variation of Intertrial Interval on Exploration of Elevated and Enclosed Mazes
Authors: Halliday M. S.
Published: July 2007

The interval between exploratory trials was varied in experiments using simple elevated or enclosed mazes. Activity on the second trial was depressed for short intertrial intervals but had recovered after about 10 min.; the degree of recovery was different in the two types of maze. A second decrease in second trial activity was found with inter-trial intervals of more than 20 min., but a further experiment suggested this was due to the effects of delay itself, rather than to previous experience of the environment.
Some Relevant Factors in the Transfer of Material from Short-Term to Long-Term Memory
Authors: Cohen Ronal L. , Johansson Bo S.
Published: July 2007

The relationship between short-term memory (STM) and long-term memory (LTM) for digits was investigated by means of a Hebb-type experiment, viz. a presentation of a series of nine-digit numbers, in which a certain number recurs at intervals. Improvement in performance, with regard to the critical, or recurring, number was found when the rehearsal grouping was three-three-and-three, but was absent when there were no opportunities for rehearsal or when the rehearsal strategy was grouping five-and-four or searching for systematic numbers.

However, if an overt recall response was given on each occasion the recurring number was presented, improved performance was found even with rehearsal strategy five-and-four.

The conclusion was drawn that rehearsal is the main transferring mechanism from STM to LTM, with the occurrence of an over recall response as a subsidiary factor.
Kinaesthetic Judgements of the Direction of Line by Young Children
Authors: Over Ray , Over Joan
Published: July 2007

The ability of young children to make kinaesthetic judgements of direction of line has been studied under recognition and detection conditions. Some children were not more accurate than chance when they were required to indicate the same one of a pair of mirror image oblique lines over a series of trials; these children could, however, detect whether two obliques were oriented in the same direction or in different directions. These latter data suggest that the poor recognition of mirror image obliques arises from deficiencies in spatial categorizing and not in input coding. This conclusion is supported by the finding that children who performed poorly on the kinaesthetic recognition of obliques performed poorly on the visual recognition of these figures.
Perceived Distance in Imagined Space
Authors: Epstein William
Published: July 2007

An experiment was designed to determine whether, in the absence of distance-cues, the perceived distance of an object is regulated by the imagined space in which the object is located. Judgements of distance and size were obtained in a completely reduced situation. Preceding these judgements, the subject engaged in 5 min. of visual exploration of the interior of an oblong box. The length of the box differed (3, 6 or 9 ft.) for different groups of subjects. The different pre-exposure conditions were expected to produce differences in the dimensions of the imagined space that the subject introduced in the subsequent test session. These differences in imagined space should lead to differences in the perceived distance of a single object located at a constant distance. Significant differences were obtained in the expected direction. In addition, judgements of the size of the standard tended to co-vary positively with the distance-judgments, suggesting that the effect of imagined space on judged distance was not simply the product of experimental biasing of the response system. Some methodological and theoretical implications of the findings are considered.
The Psychological Refractory Period as a Function of Performance of a First Response
Authors: Smith Marilyn C.
Published: July 2007

Proponents of a “single channel” theory of the psychological refractory period have not specified whether the single channel occupies only the decision component of the response selection, only the motor or response component, or both. In this experiment, the delay in the RT to the second of two successively presented stimuli was examined as a function of whether or not an overt motor response was made to the first stimulus, keeping the decision component constant. It was found that in both conditions RT2 was delayed, suggesting that the decision component was a part of the single channel. However, RT2 was delayed by a significantly greater amount if a motor response was required, indicating that the motor component is part of the single channel as well. Implications of the results for an expectancy theory of the psychological refractory period are discussed.
Comments on “Selective Attention: Perception or Response?” Reply
Authors: Deutsch J. A. , Deutsch Diana , Lindsay P. H. , Treisman Anne M.
Published: July 2007

We cannot understand why Treisman and Geffen (1967) think their experiment argues against our theory (Deutsch and Deutsch, 1963). Briefly, Treisman and Geffen ask subjects to repeat and tap to certain words in one message, played to one ear, and only tap to such words when they occur in another message played to the other ear. They find that subjects neglect the words to which they only have to tap. According to our theory, stimuli with a greater weighting of importance inhibit certain outputs (such as storage, motor response) of the structures processing stimuli with a lesser weighting of importance. Now it seems to be clear that Treisman and Geffen have by their instructions (to tap and repeat one set of words and only to tap to another set of words) produced a situation in which one set of stimuli is given a larger weighting of importance than the other. It is therefore not surprising on our theory that the less important set is almost disregarded. It is instructive here to consider Lawson's (1966) very similar experiment. In this experiment the signals to which the subject has to tap do not also have to be repeated if they occur in the message which is being shadowed. (These signals are non-verbal.) Lawson's results are almost the opposite of Treisman and Geffen's, as would be expected from our theory. Treisman and Geffen have some difficulty in explaining the discrepancy. “It seems that analysis of simple physical signals precedes both the selective filter and the analysis of verbal content in the perceptual sequence, that the bottle-neck in attention arises chiefly in speech recognition where of course the information load is usually much higher. To confirm the belief that the verbal content of the secondary message was not being analysed, we find no evidence whatever of interference from secondary target words when these received no tapping response.” (We quote the last sentence as just one example of the fact that Treisman and Geffen have failed to understand our theory. It is one of the major points of this theory to explain why “secondary” messages do not cause interference with the “primary” message while they are being analysed.) To return now to the subject of Lawson's experiments, we would suggest that the outcome of such experiments would be the same if instead of signals, words were used in Lawson's paradigm. These words should occur on both channels and should be distinguishable by another speaking voice. The subject should be asked to respond to, but not to repeat such words. To make sure the subject is not simply responding to differences in timbre, pitch, etc., the target words should be interspersed with other words. Treisman and Geffen could not then postulate differences in information load to explain an unfavourable result.
The Patterns Seen when Alternating Electric Current is Passed through the Eye
Authors: Wolff J. G. , Delacour J. , Carpenter R. H. S. , Brindley G. S.
Published: July 2007

When alternating current of frequency up to 210 c's. is passed through the eye while the retina is brightly and uniformly illuminated, conspicuous spatial patterns are seen. Other such patterns are seen when current of frequency up to 100 c/s. is passed through the eye in darkness. These patterns are here described, and their origin is discussed.
Voluntary Attention in Peripheral Vision and its Effects on Acuity and Differential Thresholds
Authors: Grindley G. C. , Townsend Valerie
Published: July 2007

The three experiments described in this paper were intended to show whether voluntary attention to a particular part of the peripheral visual field had any effect on the accuracy of the subject's perception. Test objects near to threshold value (for acuity or for changes in luminance) were used. The experiments were also designed to study the possible distracting effect of other stimuli presented simultaneously in different parts of the field.

In Experiment 1 the subject could be given foreknowledge of the position in which an acuity test object would appear. In Experiment 2 the signal of where to attend was given simultaneously with the exposure of an acuity test object. In Experiment 3 differential thresholds for luminance were investigated by methods similar to those used in Experiment 2.

It was found in all these cases that the instructions to attend to a particular part of the peripheral field had no significant effect on perception unless there were simultaneously exposed “competing” stimuli in other parts of the field. The results support the view that, in peripheral vision, attention acts selectively on the immediate memory trace only when there is a complex pattern of stimulation.
Cross-modal Induction of Changes in Sensory Thresholds
Authors: Hardy Gail R. , Legge D.
Published: July 2007

Two experiments are reported in which subliminal stimulation of one modality with emotional material impairs detection performance in a different modality. In the first experiment the visual awareness threshold for neutral material was raised by simultaneous auditory presentation of emotional words. This result supports the hypothesis that threshold changes induced by emotional stimulation are mediated centrally. In the second experiment a similar effect was obtained when the experimental roles of the two modalities were reversed. An analysis of the effect in terms of the parameters of Signal Detectability Theory indicates that it is mediated by a lowering of the sensitivity of the detection mechanism. This may be caused either by attenuation of incoming signals, or by an increase in the level of “noise” against which the signal is received.
The Effect of Stimulus Amplitude on the Threshold of Fusion of Paired Flashes
Authors: Venables P. H. , Warwick-Evans L. A.
Published: July 2007

Four experiments are described in which the threshold of fusion of paired flashes was measured. The intensity of the single flashes making up the pairs was varied independently. The results showed that when the first flash of the pair was the more intense, the threshold of fusion increased linearly as the difference in the log intensity of the two flashes. A proposal put forward to explain the results suggested the “noise” created by the first flash of the pair has to dissipate to a critical extent to allow the “signal” arising from the second flash to be detected.
Instructions, Self-Instructions and Performance
Authors: Jones Sheila
Published: July 2007

Four semantically equivalent instructions were used for a classification task, in which response was required to the larger of two classes of items. The variables in the instructions were (1) the explicitness of the negative used to define the smaller class, and (2) the order of reference to this class within the sentence. Superior performance was obtained with instructions containing “except” compared with those using “not,” regardless of order. Analysis of the self-instructions generated by the subjects, prior to performance, indicated that their form was largely determined by the given instruction. Speed of performance was related to form of self-instruction elicited prior to the task, but not to that elicited after completion of the task.
Periodicity within Reaction Time Distributions and Electromyograms
Authors: Harter M. Russell , White C. T.
Published: July 2007

This study investigates a periodic component in reaction time frequency distributions, that is, a tendency for responses to occur at regular, discrete intervals of time after stimulus presentation. Reaction time frequency distributions were plotted by a Computer of Average Transients and were obtained under stimulus conditions varying in sense modality stimulated (auditory and visual), and the intensity, colour, and duration of stimulation. The results indicated that there was periodicity in reaction time frequency distributions with a modal period of approximately 25 msec. It was found that the periodicty (a) was most evident when there was considerable variability in reaction time, and (b) tended to attenuate when a large number of reaction times were grouped. Other stimulus conditions appeared to have little effect on the periodicity. A significant correlation was found between the frequency of periodicity in the reaction time distributions and the electromyograms, both having a modal period of 25 msec. It was concluded that the periodicity in reaction time was the result of motor processes.
Three Kinds of Error-Signalling Responses in a Serial Choice Task
Authors: Rabbitt Patrick M. A.
Published: July 2007

During serial self-paced choice response tasks mean reaction times (RTs) for responses which are made in order to correct errors are faster than mean RTs for other correct responses. Experiment I showed that subjects can accurately correct errors in a four-choice task by making the response which they should have made, even though they are given no indication that an error has occurred. Experiment 2 showed that subjects correct their errors faster and more accurately when they use correction procedure than when they make a common response to all errors. The implication that subjects can correct errors because they know what response they should have made allows some comments on the constraints which must be met by various models which have been proposed to explain error-correction.
Sentence Retention and Transformation Theory
Authors: Wright Patricia
Published: July 2007

The number of words recalled in addition to a sentence can be used to measure the amount of space a sentence occupies in immediate memory. Generally an active sentence (K) requires less space in memory than a passive negative sentence (PN). But in the present experiments it was found that when subjects were presented with a block of sentences of only one syntactic form, there was no longer a difference in the amount of space needed to store K and PN sentences. However, the difference between K and PN reappeared when the tense of the verb in successive sentences was varied, even though the material was still presented in a block of either all K or all PN sentences.

These results were interpreted as suggesting that subjects were remembering words and phrases from each sentence rather than deriving kernal strings and remembering transformation tags.
Effects of Grouping on the Pupillary Response in a Short-Term Memory Task
Authors: Kahneman Daniel , Onuska Linda , Wolman Ruth E.
Published: July 2007

Subjects heard strings of nine digits for immediate recall, either at a monotone 1/sec. rate or in groups of three digits separated by pauses. Concurrent measurements of pupil size show a steady dilation in the monotone condition, and brief dilation-constriction waves during the pauses of grouped presentation. The results are consistent with hypotheses concerning rehearsal in the two modes of presentation. Pupillary dilations apparently accompany episodes of covert rehearsal.
Distraction and Time Estimation
Authors: Von Sturmer Guy , Wong Tong , Coltheart Max
Published: July 2007

It is argued that events which occur during an interval of time which is being judged may be classified in terms of their effects on the alertness of the subject, and in terms of the degree to which they distract him from the task of detecting and processing time-relevant cues. A distracting task, defined by the number of arithmetical operations a subject was required to perform, was presented while reproductions of an interval were being made. The data support the prediction that the higher the level of distraction, the less time a subject will judge to have elapsed during an objective period.
Response-Times at Different Positions within a Sentence
Authors: Kennedy R. A. , Wilkes A. L.
Published: July 2007

Response latency has often been used to draw inferences about scanning operations in serial lists. Different models have been employed and this experiment tests their predictions when a sentence replaces a serial list. Constituent analysis is used to predict an increase in latency when responding involves crossing a constituent boundary. This prediction is confirmed, and it is found necessary to revise those explanations derived from studies using serial lists to include reference to the syntactic structure of the linguistic material used.
Visual Complexity and Stimulus Pacing in Chicks
Authors: Dutch J.
Published: July 2007

Two groups were tested for spontaneous alternation using massed and spaced trials but alternation rate was not above chance level. Two experiments then examined the use of visual stimuli as pacers for an approach response. The results indicate that subjects responded to complexity and that complexity may be a more effective pacer than novelty.
The Demonstration of Dichoptic Flicker Effects by Use of Polaroid
Authors: Kinsbourne M. , Coughlin P. J.
Published: July 2007

A simple way of setting up dichoptic flicker with variable phase relationship is described. Sine wave flashes result, and for these, as for square waves, Sherrington's hypothesis of independent testing for intermittence of inputs to each eye is approximately borne out. Observations of the attributes of these two modes of stimulation at sub-fusion frequencies suggest that no such independence holds for computation of luminous flux over time.
Grouping and Short-Term Memory: Different Means and Patterns of Grouping
Authors: Ryan Joanna
Published: July 2007

Two experiments, concerned with the improving effects of grouping on auditory short-term memory, are described. In the first, temporal grouping was found to improve recall considerably, but non-temporal grouping had a much smaller effect. Temporal grouping reduced the order errors more than other errors; it also changed the pattern of the order errors. Further, it altered the shape of the serial position curve of all errors. In the second experiment, irregular patterns of temporal grouping were found to be inferior to a regular pattern. The results are discussed in terms of the time available for processing previous items during the presentation of a sequence, and the form that this processing may take.
Reading and Typing
Authors: Shaffer L. H. , Hardwick J.
Published: July 2007

As an extension to an earlier study on typing, an experiment was carried out on skilled touch typists in which they were asked to type texts that differed in word structure and word length. It was predicted from certain assumptions about the reading process that there should be significant effects of structure, length and their interaction. These predictions were confirmed.
Evidence for a Time Constant in Rate of Speech under Delayed Auditory Feedback
Authors: Salter D. , Clarkson J. K.
Published: July 2007

This experiment investigates an apparent discrepancy in experimental measurements of the effect of texture predictability upon reading disruption under delayed auditory feedback (DAF). By measuring relative DAF decrement in three different ways, it is shown that the previous findings can be related; Fillenbaum's hypothesis of increased disruption by DAF with an increase in predictability of the material is rejected, less disruption being obtained after practice on a particular passage. Almost identical ratios of DAF rate divided by normal rate are found irrespective of the type of reading material and stage in practice. This has not been reported previously and suggests that behaviour under DAF may be related to behaviour under normal conditions by a multiplicative constant. These results are also consistent with the notion of limited channel capacity and the partitioning of attention between two sources of information.
Coding Factors in Transcription
Authors: Shaffer L. H. , French Ann
Published: July 2007

Two experiments looked at aspects of stimulus grouping by trainee typists and tested for the possibility of response grouping. Manipulating text preview indicated that typing speed declined if the next word was not wholly on display but, conversely, there was little gain if it was displayed much in advance of its being typed. Some of the effect of practice was specific to the words actually typed: words not presented during practice were typed slower than practised ones; others given reinforced practice were typed quicker than the rest. An analysis of response latencies provides evidence that response grouping sometimes occurred.
Shadowing and Monitoring for Selective Attention
Authors: Underwood Geoffrey , Moray Neville
Published: July 2007

Although shadowing has been assumed to hold attention strongly (e.g. Hochberg, 1970) this has not been demonstrated, and the incidence of errors and intrusions suggest that it is not as powerful a technique as might have been supposed. An alternative, simpler, technique would be monitoring, but Kahneman (1970) maintains that selectivity fails in the absence of a continuous response. The experiments here compare the shadowing and monitoring tasks when attentional selectivity was required, and when it was not required, and indicate that similar attentional strategies operate during the monitoring and shadowing of brief messages. The shadowing paradigm is criticized in terms of an interaction between the relative resemblance of the stimuli and the shadowing voice. It is not demonstrated that an absolute interaction takes place, but more importantly that relatively greater interference is apparent when the shadower's voice and the stimuli to be shadowed are similar than when they are distinct. It is suggested that low target detections in the unattended message may be an artifact of the processing requirements of the shadowing task.
Response Retrieval in Active and Passive Sentences
Authors: Wilkes A. L. , Kennedy R. A.
Published: July 2007

Retrieval latencies for active and passive sentence examples are compared. The argument is proposed that the sentences are searched by means of a strategy that permits direct entry into specific word groupings. Both syntactic structure and pausing behaviour are considered as indices of the groupings employed. It is concluded that neither descriptive source can on its own fully account for the obtained latency profiles, although the structural description derived from pause location provided a better prediction than constituent analysis. The implications of this conclusion are discussed.
A model for Subjective Grouping in Typewriting
Authors: Thomas Ewart A. C. , Jones Richard G.
Published: July 2007

An experiment in typing is described in which the visual spacing in the text and the amount of linguistic structure in the material are varied. The results show that average typing speed is decreased both by removing visual spaces from the text and by decreasing the amount of structure in the material. The data are interpreted as evidence that there is response grouping in a typist's output, and a model is stated in which this grouping is attributed to the operation of a response-unit scanner. More detailed analysis by means of this model suggests a picture of serial and parallel information processing to be an adequate representation of the conversion of text into type.
Preprocessing on the Basis of Frequency of Occurrence
Authors: Thomas Ewart A. C. , Wickens Delos D.
Published: July 2007

The release from PI methodology was used to test Oldfield's (1966) suggestion that human memory is organized in part on the basis of frequency of occurrence. An observed release from PI identified frequency of occurrence as an encoding category and provided support for the underlying assumptions of Oldfield's model.
Avoidance Learning by Guinea Pigs
Authors: Sansone Mario , Bovet Daniel
Published: July 2007

Albino guinea pigs were trained in shuttle-boxes. Superior performances were achieved with longer CS–US (15 sec. against 5 sec.) and intertrial intervals (90 sec. against 30 sec.). There were no performance increments within sessions, but improvements in performance occurred between sessions. Consolidation mechanisms probably play an important part in avoidance learning by guinea pigs.
Interaction of Fear Effects with Habit Strength
Authors: Manocha Satinder N. , Winocur Gordon , Mills John A.
Published: July 2007

Four groups of rats received 0, 3, 6 or 9 days of overtraining after having reached stable performance on a continuous reinforcement bar pressing schedule. Half the subjects in each group had previously been designated emotionally reactive or non-reactive in terms of defecation rates in an open-field test. Following training, there were four test days in which bar pressing in each group was examined in the presence or absence of white noise. The major findings were that, in both the reactive and non-reactive groups, white noise produced a fear reaction which significantly depressed bar pressing at low levels of habit strength while having an energizing effect at higher levels. The results were interpreted as supporting Bardach's (1960) hypothesis that anxiety introduced early in practice is more disruptive than when introduced late in practice.
An Aspect of Perceptual Organization Involved in Reading Typed and Handwritten Words
Authors: Corcoran D. W. J. , Rouse R. O.
Published: July 2007

Three experiments of identical design, but using different basic materials are reported. In experiment I the probability of recognizing tachistoscopically presented typed and handwritten words was found (a) when the two types of materials were presented in separate lists, and (b) when presented together in a mixed list when subjects did not know what type of material to expect next in the sequence. In Experiment II, two handwritings were employed and in Experiment III, upper and lower case typed material was used.

The mixed condition resulted in poorer performance than the unmixed condition only in Experiment I when typing and handwriting were used. In Experiments II and III, mixing had no effect.

It is suggested that different recognition programs are used for typed and hand-written characters.
Vibrotactile Learning and the Locus Dimension
Authors: Diespeckek D. D.
Published: July 2007

Forty subjects, each of whom was randomly allocated to one of four experimental groups, learned a 26-element vibrotactile code. Each group used either 3, 4, 5 or 6 vibrators. As predicted, the performance of each group improved in the order 3−, 4−, 5− and 6−vibrators. Although there were no significant differences between the groups there was a highly significant learning effect over ten trials. Error analyses showed that duration errors were the most frequent type of error and that intensity errors were the least frequent. It is suggested that both the types of errors and the optimum number of loci which can be separately stimulated in this type of experiment will depend upon the spacing and arrangement of signal elements.
Infantile Handling and the Extinction of Responses Acquired under Food Reward
Authors: Wong Roderick
Published: July 2007

A comparison was made of the runway behaviour of rats which had been handled from Days 1–21 and their non-handled litter mates. The training began on Day 70 after the animals were habituated to a restricted food schedule for 10 days. The subjects were given six trials each day in the runway and were rewarded with a 0.045 g. Noyes pellet. After 10 days of rewarded training trials, subjects were given 6 extinction trials a day for 10 days. Results showed that handled rats ran faster than non-handled rats during acquisition and during the first 3 days of extinction. The extinction data suggested that the relationship between emotionality and effects of frustrative non-reward should be re-evaluated.
A Developmental Study of form Discrimination in Pre-School Children
Authors: Taylor John A. , Wales Roger J.
Published: July 2007

Using a matching-from-sample technique the discriminative ability of a group of pre-school children was tested twice, at mean ages 3–8 and 4–9, in relation to an independent test of their comprehension of the notion “same”. A sequence of three stages is described, for both shape and orientation discrimination; in the first, characterized by a large number of errors, the child appears to respond largely in terms of proximity of a comparison figure to the standard; in the second his responses reflect gross aspects of similarity between the figures in the comparison set, in that several matches are made to one standard all of which have certain attributes in common with it. Finally correct and unique choices are made. Attributes used in differentiating figures are described, and a number of theoretical and methodological problems are discussed.
Imagery and Compatibility of Pairing in the Free Recall of Adjective-noun Pairs
Authors: Morris P. E. , Reid R. L.
Published: July 2007

Can the image-evoking value (I) of single words be used to predict the recall of grammatical units in which they occur? Thirty-two subjects free-recalled a list of 24 adjective-noun pairs varying in the I of the adjective and the noun, and the compatibility (C) of the pairing (i.e. whether or not the pair was immediately meaningful). Analysis showed all three variables to affect recall. High I adjectives facilitated recall irrespective of the I of the noun or the C of the pairing. Noun I and C facilitated recall only when both noun I was high and the pairing was compatible. An examination of intertrial repetitions failed to find evidence of organization in recall. Where only one word from a pair was recalled it tended to come from an incompatible pair, supporting the hypothesis that the recall of one word from an incompatible pair is less likely to cue recall of the other word than is the recall of one word from a compatible pair.
Discovery as a Means to Understanding
Authors: Legrenzi Paolo
Published: July 2007

Two experiments were conducted to determine whether the discovery of a conditional rule from its instances facilitated a test of its truth from partially concealed information, compared with a situation in which the rule was presented directly. In the first experiment the subjects who discovered the rule expressed it in their own words. The results showed that they tested it significantly better than a control group who were presented with the rule, as expressed by the subjects in the experimental group. In the second experiment the subjects in the experimental group were compelled to express the rule in the form of a conditional sentence. The results showed again that they performed significantly better than those in a corresponding control group.
Serial Position Effects in the Recall of Picture Sequences
Authors: Cohen Gillian
Published: July 2007

Sequences of 10 pictures of familiar objects were presented for immediate recall, and typically bow-shaped serial position curves were obtained. The effects of redundant stimulus suffixes, and of redundant stimulus prefixes, which could be either extra pictures, or written words (the names of similar familiar objects) were examined. In the prefix conditions, extra words produced a general decrement over positions 1–4, as compared with a control condition. Picture prefixes had no effect. In the suffix conditions, redundant words affected positions 9 and 10, whereas the main effect of redundant pictures was at positions 8 and 9. The differential serial position effects are taken to reflect the presence of two memory codes, a verbal one and a visual one, which vary in trace-strength or accessibility at different list positions.
Remembering Complex Sentences
Authors: Wearing Alexander J.
Published: July 2007

Recall of complex sentences at two retention intervals was examined, using sentences which varied simultaneously in three ways, being either active or passive, of low or high Yngve depth, and predictable or unpredictable. Recall of any particular sentence was cued with either the logical subject, logical object, verb or adverbial phrase noun. In general, unpredictable sentences were recollected better than predictable ones, low Yngve depth sentences were recalled better than high Yngve depth ones, and passive sentences were retained better than active ones. The most effective cue was the object, followed in turn by the subject and the adverbial phrase noun, with the verb being least effective. Implications of these findings are discussed.
Acquisition, Extinction and Reacquisition of a Conditioned Response in the Cockroach: The Effects of Orotic Acid
Authors: Rick J. T. , Oliver G. W. O. , Kerkut G. A.
Published: July 2007

Cockroaches can be trained to keep their metathoracic leg out of a saline solution. Isolated metathoracic ganglia learnt faster than headless animals, which in turn learnt faster than intact animals. Extinction took longer in the isolated ganglion than in the other two preparations. Extinction times increased with increasing dose of orotic acid, a precursor of RNA. Orotic acid did not systematically affect the times for acquisition and reacquisition of the learnt response.