bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Rate of Gain of Information
Authors: Hick W. E.
Published: March 2008

The analytical methods of information theory are applied to the data obtained in certain choice-reaction-time experiments. Two types of experiment were performed: (a) a conventional choice-reaction experiment, with various numbers of alternatives up to ten, and with a negligible proportion of errors, and (b) a ten-choice experiment in which the subjects deliberately reduced their reaction time by allowing themselves various proportions of errors.

The principal finding is that the rate of gain of information is, on the average, constant with respect to time, within the duration of one perceptual-motor act, and has a value of the order of five “bits” per second.

The distribution of reaction times among the ten stimuli in the second experiment is shown to be related to the objective uncertainty as to which response will be given to each stimulus. The distribution of reaction times among the responses is also related to the same uncertainty. This is further evidence that information is intimately concerned with reaction time.

Some possible conceptual models of the process are considered, but tests against the data are inconclusive.
A Discrimination Based on Punishment
Authors: Dinsmoor James A.
Published: March 2008

Twelve white rats learned to press a bar or lever when this act was intermittently followed by pellets of food. Once a stable rate of pressing had been established, the animals were subjected to electric shock as a punishment for each response during alternate five minute periods within the experimental session. A difference in rates during the safe and punished phases was manifested both by the experimental group (8 rats), who were provided with a light as a signal when it was safe to respond, and also, contrary to expectation, by the control group (4 rats), who continued in darkness throughout the session. The differential responding by the control group was greatly reduced, however, when the duration of each phase was reduced from five minutes to one.

The investigation was then continued to determine the role of some of the other factors in the situation. Increasing the severity of the shock increased the difference between the light and the dark rates. Withholding the pellets of food reduced the overall rates but did not affect the light-dark discrimination. Withholding the shock, on the other hand, permitted an increase in rate and caused the animals to lose their discrimination; when food had previously been withheld, however, so that the rate of response was relatively low, this deterioration in the discrimination was not as rapid as before. Restoration of the discrimination training under a lower hunger drive confirmed the finding that the formation of the discrimination was quite rapid and showed that the level of drive did not affect the proportionality between the rates in the light and in the darkness. These findings were interpreted by comparing the current procedure with those previously used in studies of avoidance reactions and conflict.
A Test of Sensory Pre-Conditioning in Pigeons
Authors: Reid R. L.
Published: March 2008

Sixteen pigeons were used in an experiment designed to show the sensory preconditioning effect as originally reported by Brogden. An experimental group received 200 simultaneous presentations of a buzzer paired with a light stimulus. They were then trained to respond to one of these stimuli alone and tested for response to the other. A control group received the same treatment except in the initial stage when 200 presentations of the test stimulus only were given. The results provided no evidence that the pairing of stimuli affected behaviour during the critical test.

Both groups responded to the test stimulus to a similar degree in this experiment, whereas in Brogden's original study with dogs experimental animals responded significantly more frequently than did their controls. The discrepancy in results can be attributed to the use of different control procedures in the two experiments. Brogden's controls were not exposed to presentations of the test stimulus before training. Differences in familiarity with this stimulus may have produced the differences between the behaviour of his control and experimental animals. This interpretation is supported by the result of a preliminary experiment with pigeons in which Brogden's control procedure was used and his original results confirmed.

With human subjects there is some evidence that pairing procedures may result in enhanced generalization, alterations in sensory thresholds or hallucinations. However, these effects are little understood and difficult to predict. Although no functional relationships like those found in ordinary conditioning have yet been shown to apply, the terms “sensory conditioning” and “sensory pre-conditioning” have been widely used and the data have been quoted in support of theories of learning that require the setting up of direct sensory-sensory relationships.

Until there is unequivocal evidence of pairing effects with animals or fuller knowledge of the occurrence of such effects with human subjects, it is considered unadvisable to link them even by name with basic learning mechanisms such as conditioning.
Blinking during Visual Tracking
Authors: Poulton E. C. , Gregory R. L.
Published: March 2008

In order to determine the incidence of blinks during visual tracking, their effect, and the nature of this effect, two experimental arrangements were used. In one the subject had to keep a pen upon a moving line, his blinks being recorded without his knowledge both electronically and by two observers. In the second he had to keep two pointers in line using a positional control, the display being occluded intermittently in one part by a wheel tachistoscope, in another by his own voluntary blinks.

It was found that the blink rate was raised when the subject expected the tracking to start, and again after tracking. During tracking it was reduced, particularly initially. The lowest blink rates were recorded during or immediately before the difficult periods of the course. It was not possible to predict the blink rate while tracking from a knowledge of the true “resting” blink rate.

Although blinks were Infrequent when the course was difficult, it was here that they caused the largest errors, especially when anticipation was not possible. This effect was due partly to interference with vision, but only temporary inattention could account for the delayed deterioration following blinking. It has been suggested that the blink rate might serve as an index of attention, blinking being one of the earliest signs of inattention.
The Sensibility to Passive Movement of the Human Elbow Joint
Authors: Cleghorn T. E. , Darcus H. D.
Published: March 2008

The literature on the perception of passive movement is reviewed. A description is given, of an apparatus whereby passive movements may be produced at the human elbow joint with the minimal amount of interference with sensation from extraneous factors. Tested with this apparatus, four human subjects experienced in varying degree false sensations of movement when the arm was at rest. They differed from each other in the direction which they tended to ascribe to the sensations, three of them being strongly influenced by the direction of the preceding movement.

Both the perception of movement and identification of its direction were more efficient in extension than in flexion and at larger than at smaller displacements. The duration of movement was an important factor. Tentative estimates of the threshold are: 0·8° for 80 per cent, correct detection of movement and 1·8° for 80 per cent, correct identification of direction at all speeds in the range, 0.10·0.25°/sec.
Phenomenal Causation at a Distance
Authors: Yela Mariano
Published: March 2008

The aim of this research was to study the finding by Michotte, that a moving object A can apparently produce movement in a projectile B without making contact with it.

The experiments confirm the existence of a causal impression of “pushing at a distance,” but they demonstrate that the greater the distance the smaller the chance that this impression will occur.

When it does, in fact, occur, it has the same characteristics, and is associated with the same experimental conditions, as the impression of “pushing with contact.”

Temporal continuity must obtain between the stopping of the moving object and the starting of the projectile; this refutes any theory positing that there is a “passage” of movement from one object to the other. The effects of differences in speed of movement, whether absolute or relative, are similar in both instances.

In general, however, it appears that distance slightly accentuates the segregation of the movements and that the temporal and kinematic conditions of integration require to be more favourable in the case of distance, if an impression of pushing is to be given which is as satisfying as that found in the case of direct contact.

The size of the Radius of Action, that is, the extent of the passive phase of the projectile, is of the same order in the two cases.

The results bring out the fundamentally temporal-kinematic nature of the perceptual pattern of pushing. They appear difficult to reconcile with an interpretation based on past experience, but tally with the theory of “Ampliation of Movement” put forward by Michotte. According to this theory the essential point lies in the phenomenal transitory belonging to A (the moving object) of the movement performed by B (the projectile).
Relationship of Motivation and Method of Testing to Distribution of Practice Phenomena in Rotary Pursuit
Authors: Ammons Robert B.
Published: March 2008

Women college students (N = 120) practised 60 r.p.m. rotary pursuit for 12 minutes, rested for approximately 25 minutes and then practised for 12 minutes more. During the initial period, thirty-six 20-second trials were given, 20 subjects each practising with intertrial rests of o seconds, 20 seconds, 50 seconds, 2 minutes and 5 minutes. In the 12-minute post-rest or testing period, 10 subjects in each of these groups practised continuously, and 10 were given 20-second trials separated by 5-minute rests.

Greater distribution was found to lead to better performance in the initial period, except that the 5-minute inter-trial-rest group did not perform as well as the 2-minute group.

The warm-up decrement was dependent on the degree of distribution of practice in the initial period, being greater with greater massing of trials. As measured by the backward-extrapolation method, less was shown when testing practice was continuous than when it was distributed.

The temporary work decrement was far greater in magnitude than the permanent work decrement. If permanent work decrement was present at all, it was small in magnitude; approximately one-half was due to the conditions under which it was tested for, rather than to the degree of distribution in the initial stages of practice.
Variations in Blink Rate during Non-Visual Tasks
Authors: Gregory R. L.
Published: March 2008

A total of fifty-five subjects were tested in three experimental situations. Blinking was recorded electrically, and related to various features of the three non-visual tasks. A new type of suction electrode was developed for this purpose.

It was found that blink rate fell below the normal resting rate during the learning of a stylus maze, and during a special audio-tracking task. During pauses between each trial, blink rate was above the resting rate.

There was a significant tendency for those subjects who showed the greatest difference in blink rate during the trials and the pauses between each trial to make the fewest errors per run of the stylus maze.

In the audio-tracking task the subjects followed a changing note with a second oscillator. Blink rate was found to be inversely related to the rate of change of the course tone.
The Apparent Length of a Line as a Function of Its Inclination
Authors: Pollock William T. , Chapanis A.
Published: March 2008

In the first of two experiments reported here, subjects adjusted the length of a variable line until it appeared to be as long as a standard line. There were two sizes of standard line, 3 and 6 inches, and each was shown vertically for some trials and horizontally for others. The variable line was presented in each of the 10° positions from 0° (horizontal), through 90° (vertical), to 170°. The principal results of the first experiment are: (1) Vertical lines look longer than horizontal lines of the same length, but lines tilted 20°-30° to the left of vertical look longer than lines in any other orientation. The results are asymmetrical, because lines tilted to the right of vertical do not look as long as those tilted to the left of vertical. (2) The variability of the settings increases as the angle increases between the standard and variable lines. (3) When they are expressed in percentage terms, the data obtained with the 3-and 6-inch standards are virtually identical, i.e. the data for the 3-inch standard can be made to match those for the 6-inch standard simply by doubling the former. (4) There are enormous differences among subjects in the patterns of settings made at the various angles. A few subjects apparently experienced no illusory effects since they adjusted the variable line to about the same physical length irrespective of its orientation. Other subjects showed exaggerated overestimations of the variable line for vertical and near-vertical positions.

In the first experiment, the variable line was always to the left of the standard, and it was natural to assume that this position effect had somehow produced the asymmetry noted in paragraph 1 above. This hypothesis was tested in the second experiment which alternatively showed the variable line above, below, to the right of, and to the left of the standard line. The results of this experiment generally confirm the data of the first experiment in showing that lines tilted 20°-30° to the left of vertical look longer than lines tilted to any other position. In addition, the second experiment shows that this asymmetry in the results is not a function of the relative positions of the variable and standard lines. In general, however, overestimations of length are smaller when the two lines are one above the other, greater when the two lines are side by side.
Subjective Assessments of Firmness: The Use of a Rating Scale
Authors: Sheppard D.
Published: March 2008

An experiment was carried out to investigate the extent to which an absolute standard for firmness could be held independently of variations occurring within the samples being judged.

Although the method gave good results as a whole, it was found that, when correlating the ratings to the objective measurements, the absolute standards were not held independently of the average firmness of the groups being judged. In practice, if a certain sample was judged, within a “soft” series of samples, it would be rated as being firmer than when it was judged among “firm” samples. Certain differences in the effects of these changes were related to the nature of the subjects' previous experience.

When the results were considered on a relative comparison basis, it was found that a much lower threshold was achieved than had previously been obtained with judgments for springs using paired comparison methods. There were certain trends in the levels of discrimination with time. These trends are discussed.

The strength of grip of the subjects bore some relation to their initial rating values, but apparently was not related to their level of discrimination. Subjects who were able to exert a more constant pressure throughout the test did not seem to be any better at discriminating than were others.

Ratings made for a single sample two months after the main experiment were very similar to those previously given for the same sample.
The Interaction of Hunger and Thirst in the Rat
Authors: Danziger K.
Published: March 2008

Two groups of rats were given a series of trials in an enclosed runway with a food reward at the end, one group being run hungry, the other hungry plus thirsty. Then each group was split into three sub-groups: one run hungry, the second thirsty and the other hungry plus thirsty, in each case without food reward.

It was found that, whereas on the rewarded runs the extra, “irrelevant,” thirst increased running speed, on unrewarded runs it had the opposite effect and slowed up performance. Thus on unrewarded runs the two sub-groups running thirsty, and hungry plus thirsty, ran as slowly as those running hungry. Differences were found not to depend on whether the animals had been hungry or hungry plus thirsty on previous rewarded runs.

The interaction of primary needs therefore depends on the external situation. This can be accounted for in terms of the Pavlovian theories of mutual induction and conditioning, but not in terms of Hull's theory of “irrelevant drives.”
The Influence of Adaptation on Absolute Threshold Measurements for Olfactory Stimuli
Authors: Cheesman G. H. , Mayne Stella
Published: March 2008

A group-test method of determining the mean absolute olfactory threshold to a test stimulus for a group of subjects is described. Probit analysis is employed to evaluate the results. This technique is utilized to measure the change in sensitivity to the test stimulus due to adaptation to the masking stimulus. When the values of the logarithm of the threshold concentration of the test stimulus are plotted against the logarithm of the concentration of the masking stimulus for a pair of odorous materials, a straight line is obtained. It is suggested that the gradient of this line may be used as a measure of the degree of community of odour-property between the pair of substances.
The Part Played by Intellectual Processes in a Sensori-Motor Performance
Authors: Vince M. A.
Published: March 2008

An experimental method is described for investigating the relation between intellectual processes and hand movements as both develop during the learning of a skilled task. Subjects were required to make predictive movements to join a series of circles; these appeared one at a time and were arranged in a pattern which was repeated thirty-two times. Comparison between the record of predictive movements and the subject's drawing of the pattern, made at the end of the experiment, showed that errors in the drawing corresponded to the type of response first made when the whole pattern was unfamiliar. For this reason it is suggested that the making of the responses played a part in the development of the idea of the pattern of circles, but the relation between the two is not a simple one.
Advance Information in Sensori-Motor Skills
Authors: Leonard J. A.
Published: March 2008

Two experiments were carried out to demonstrate the effects of advance information. In both cases greater smoothness of performance was found to be possible when advance information was available. This effect was considered more important than the reduction in response time. Both effects were reflected in a reduction of the stopping times between successive responses.
Fixations, Position Stereotypes and Their Relation to the Degree and Pattern of Stress Part II
Authors: Knöpfelmacher F.
Published: March 2008

In a group of white rats who developed position stereotypes in a Water discrimination unit under conditions of low punishment, the behaviour of four animals was closely akin to what Maier calls “abnormal fixations.” The stereotype-extinction scores of subgroups containing these animals were distributed in separated clusters. Punishment differentiated response latencies, and this furnished evidence that the fixated animals had mastered the soluble problem in spite of not responding appropriately.

These findings and other findings from the same experiment, which were reported previously (Knöpfelmacher 1953), are interpreted as showing that though Maierian behaviour fixations were reproduced in a water discrimination unit, the properties of stereotypes are not compatible with the stress—frustration—fixation theory, at least on a molar level, and that goal—motivational learning theory can account for most though not all the data.
Some Features of the After-Contraction Phenomenon
Authors: Hick W. E.
Published: March 2008

The well-known unintentional muscular contraction following a voluntary contraction was found to be inhibited by instructions favouring relaxation, to be increased by a difficult concurrent task and to be superimposed on small voluntary contractions of the same muscles. It was not superimposed (in either sense) on antagonist contractions. An explanation is suggested, based on the interaction of sensory adaptation and some other process known to occur and apparently related to fatigue.
Some Effects of Noise on Visual Performance
Authors: Broadbent D. E.
Published: March 2008

A group of ten subjects showed impaired performance, when watch-keeping on a display made up of steam-pressure gauges, in 100 db. noise as compared with 70 db. On the easier task of watch-keeping on a display made up of small lights, another group of twenty subjects showed no overall effect of noise. Individual subjects who showed a practice effect on the latter task comparable to that shown by all subjects on the former one, however, also showed a similar effect of noise.

In addition, performance on the light-watching became relatively less efficient in noise with continued exposure: and although parts of the task were still adequately carried out, others were not. The fact that noise effects are thus functions of individual differences, of visibility of signal, and of length of performance in noise, allows us to explain the negative findings of many previous workers.
Can a Trained Subject Judge his Auditory Sensitivity?
Authors: Wertheimer Michael
Published: March 2008

Auditory thresholds were measured daily on three subjects over an extended period of time, and the subjects postdicted whether the level and variability of the day's measured thresholds were higher or lower than on the preceding day, without their having knowledge of their performance. It was found that their judgments agreed with the obtained psycho-physical data better than would have been expected on the basis of chance alone. These results raise the question of the possibility that a subject's understanding of, or hypothesis concerning, the experimental outcome may influence his behaviour.
The Influence of Previous Movement and Posture on Subsequent Posture
Authors: Jackson C. V.
Published: March 2008

An experiment with 21 subjects has confirmed the findings of other investigators that previous posture affects subsequent posture—the phenomenon of postural persistence. There seems also to be a tendency for the arm to be judged horizontal when in fact above the horizon, no matter which posture has been previously adopted—a “constant upwards effect.” It has also been found that the direction of previous movement affects subsequent posture. After movement, an overshooting effect adds to a “constant upwards effect.”

Various explanations of the phenomenon are discussed, and persistence is considered as an anomaly of postural recognition.
An Experiment with Occasional False Information
Authors: Leonard J. A.
Published: March 2008

An experiment is described in which subjects were presented, under one condition, with advance information of doubtful value. The evidence suggests that advance information was accepted, although the uncertainty created had a detrimental effect on the subjects' performance.
The Perception of Short Phrases Presented Simultaneously for Visual & Auditory Reception
Authors: Mowbray G. H.
Published: March 2008

Subjects were provided with outline maps that were incomplete in several details. Brief, simultaneous, visual and auditory instructions were given for completing some of the missing details. Certain items could be completed on the basis of direct information contained in one or other of the sensory modalities. Others, however, could be completed only because of their relation to details capable of location by direct instruction. Information important for the completion of map details was distributed randomly among short passages of unconnected words. All relevant visual and aural clues were presented simultaneously in every case. Opportunities for alternations of attention were curtailed.

Thirty-six subjects were randomly assigned to three experimental conditions, and to two groups that were given different instructions. One group was told that relevant information would always appear simultaneously, while the other group was not allowed this information.

The number of successfully located simultaneous pairs of items presented for direct location was found to be no greater than could be expected by chance. The total number of correctly located items was less than 50 per cent of the possible items. There was no difference in the number of correctly located simultaneous pairs of items between the “instructed” and the “uninstructed” groups. The “uninstructed” group did not learn in the course of the experiment that all relevant material was presented simultaneously. Significantly more correct completions were made with the visual material than with the auditory. It is concluded that successful division of attention did not occur.
The Impact of Visual Aid Displays Showing a Manipulative Task
Authors: Laner S.
Published: March 2008

A moving film and a filmstrip, composed of line drawings, were compared in respect of their efficacy in imparting instruction about a manual task. Their respective effects were tested by making the subjects actually perform the task. The chief aims of the experiment were, firstly, to determine the manner in which material presented pictorially is utilized in the approach to and execution of the task and, secondly, to assess the special effects, if any, of motion and photographic realism in the presentation.

The approach both to the perception of the material and to the execution of the task was found to be essentially constructive. For this reason much that is usually presented is superfluous while, on the other hand, points of principle necessary to adequate construction are often insufficiently clarified or emphasized. No significant difference between the moving film and the filmstrip presentation was found. It is concluded that aspects of visual aid material, such as motion and photographic realism, which are commonly assumed to be of special cognitive importance, do not themselves play a unique rôle.
A Further Study of the Pendulum Phenomenon
Authors: Hall K. R. L. , Earle A. E.
Published: March 2008

A first series of experiments had demonstrated certain conditions eliciting or inhibiting a “pendulum” phenomenon in the visual perception of apparent movement. The present study consists of five further variations designed to show more clearly conditions of occurrence and non-occurrence of this type of movement. The main findings are: (1) Altering the axis of display to vertical significantly reduces the frequency of pendular-movement perception; (2) Altering the position of metronome from behind to the side of the visual display, gives results almost identical with those where the metronome was inaudible, but, when the metronome is illuminated in this position, all forms of movement perception are reduced, and no pendular movement is reported.

The results for all the ten conditions, including the five of the first series are summarized, and the following possible factors are discussed: past experience, physiological nystagmus, and intervening adaptation. All three may be required to account for the perceptual phenomena under investigation and the dichotomizing of explanations into “experiential,” or “physiological,” appears to be arbitrary and inconsistent with the complexity of the observed facts.
The Nature of Set-to-Learn and of Intra-Material Interference in Immediate Memory
Authors: Brown J.
Published: March 2008

The influence of set on learning has previously been demonstrated under conditions where set could affect either the selection of stimuli in perception or their subsequent rehearsal. With both these possibilities excluded, set was still found to have a strong influence on learning: this suggests that set can somehow facilitate the formation of the memory trace when a stimulus is perceived.

Two forms of intra-material interference were shown to occur during the recall period. The attempt to recall one part of the material presented interfered with, and was itself impaired by, the attempt to retain the part yet to be recalled.
Drive-Level and Flexibility in Paired-Associate Nonsense-Syllable Learning
Authors: Gordon Walter M. , Berlyne D. E.
Published: March 2008

“High-anxiety” and “low-anxiety” subjects, selected for extreme scores on the Taylor Anxiety Scale, learned a list of paired-associate nonsense syllables in the belief that they were undergoing an intelligence test. Both groups were then given a second list of paired associates to learn, the stimulus-items being the same as those of the first list but the responses being changed. Before the presentation of the second list, half the subjects in each group were given anxiety-increasing instructions and the remaining half were given reassuring instructions.

The results verified two predictions made from Hull's behaviour theory, using the concept of fear or anxiety as a secondary drive:—“high anxiety” subjects took more trials to master the second learning task than “low-anxiety” subjects; and there was a significant interaction between initial anxiety-level and type of instructions, such that “high-anxiety” subjects who received drive-increasing instructions had a worse performance in the second part than all other sub-groups. There was no indication that “low-anxiety” subjects were significantly affected by the type of instructions received. The “high-anxiety” group had greater difficulty than the “low-anxiety” group in learning the first list, but the difference was non-significant.
Response Elimination without Performance
Authors: Hurwitz H. M. B.
Published: March 2008

Hungry rats were taught to press a lever in order to obtain a small quantity of food. It has been shown that the strength of the lever-pressing response can be reduced by allowing the animals to explore the box without finding food. This result conflicts with a simple reactive-inhibition theory of forgetting and response-elimination. Three possible explanations have been considered: (a) that the failure to find food changed the motivational condition of the animal; (b) that a conditioned drive, associated with the food-box, underwent extinction; (c) that a genuine response extinction occurred, and that this could be accounted for in terms of a principle of reaction-chain acquisition and extinction which differs in important respects from Skinner's (1938) and Hull's (1954) principles of conditioning.
The Relationships between P.G.R. Scores and Temperature and Humidity
Authors: Venables P. H.
Published: March 2008

Following an incidental finding that psychogalvanometer response measures were related to temperature and humidity readings taken at the same time, the nature of the relationship was examined in greater detail.

A sizeable relationship between temperature and conductance response measures is found only in a neurotic group and only above an effective temperature of 66° F. This relationship appears to be a function of the position of the response within the total experimental session, and may be dependent upon the relative excitation, or recovery from excitation, of the subject. Humidity in general, affects only the basal conductance level and, does so in both normal and neurotic groups. The relationship between temperature and humidity is probably a complicated one and cannot be corrected for by simple regression except if the majority of scores be within a particular range of humidity readings.
The Role of Spatial Stimuli in the Perception of Shape.: Part II
Authors: Langdon J.
Published: March 2008

Subsequent to the experiment described in Part I, the röle of spatial-surround cues is further investigated by attempting to modify the character of the environment. Pairs of shapes are matched, both stationary and rotating, within an Ames-type equivalent space. These shapes are of two kinds. The first is calculated for normal perceptual space, and the second pair are comparable only in the equivalent space. Comparison of matchings indicates that the perceived shape is a product of interaction between cues emanating from the object and the surround, in terms of which the object cues are evaluated, though the concept of “anchorage” or “reference frame” is distinguished from suggestions advanced by some authors.
The Effect of Goal-Setting and Encouragement on the Performance of Imbecile Men
Authors: O'connor N. , Claridge G. S.
Published: March 2008

Following previous work, three groups of imbecile men were asked to carry out a simple task over a period of nine trials. Self-competition (Goal) had previously improved the performance of one sub-group on this task significantly, and experiment showed that this improvement had been retained. By re-dividing the subjects, three groups were matched and asked to perform under different motivating conditions. These were: Control, Goal with Encouragement, and Goal with Indifference or neutrality shown by the investigator. Treatment of the results was based on the slope of regression lines. It was found that encouragement had a significant effect on the performance of subjects working under goal conditions, but that goal conditions without encouragement did not significantly improve performance over control conditions.
Editorial Board
Authors: Davis D. Russell
Published: March 2008

This is a scanned image of the original Editorial Board page(s) for this issue.
Difference-Limens for Photic Intermittence
Authors: Gebhard J. W. , Mowbray G. H. , Byham C. L.
Published: March 2008

Difference-limens for visual intermittence were measured in the range of one to 45 cps. The standard deviations obtained varied from 0.02 to 0.41 cps. and the relative difference-limens, [Formula: see text], computed from the average deviations, were from 0.005 to 0.024.
A Negative Test of the Drive-Reduction Hypothesis
Authors: Littman Richard A. , Wade Edward A.
Published: March 2008

A major deduction of the drive-reduction hypothesis of reinforcement was tested. A light which follows the termination of a shock coincides with a condition of drive or need reduction. If drive reduction is a sufficient condition for reinforcement, then the light should become a secondary reinforcing agent by virtue of its association with the drive-reduction event. If it becomes a secondary reinforcing agent, it should be able to reinforce an instrumental act.

This sequence of deductions was tested by placing rats in a stock, giving them a brief shock upon the termination of which a light was flashed for one second. After sixty such pairings, subjects were then placed in a Skinner box under operant test conditions; when they pressed the bar a light flashed on.

Animals subjected to this training programme were compared for rate of bar pressing with animals subjected to a variety of control conditions. No significant differences were found among the groups, and it was concluded that in so far as the deductions from drive-reduction theory were correct, the theory was not substantiated. The paper concludes with a discussion of various problems which might limit the interpretation of the experimental results.
The Relation between Hand Movements and Intellectual Activity in a Skilled Task
Authors: Vince M. A.
Published: March 2008

The experiment continues an investigation (Vince, 1953) into the relation between intellectual processes and hand movements in a sensori-motor task. Subjects were required to trace a repeating pattern of circles which appeared one, two or three at a time in a slit. Only one circle at a time could be hit and subjects were instructed to discover for themselves a good path for joining the maximum possible number of circles. The experimental situation thus allowed for various levels of response: pursuit movements, predictive movements, choice and a change of plan. At the end of the experiment subjects were asked to draw their idea of the pattern.

The results support others obtained earlier in showing that in this situation the subject's idea of the pattern he is tracing is determined by his total (motor, as well as visual) response to it. In addition, there was evidence that in some cases improvements occurred in the sensori-motor performance which were not reflected immediately in the subjects' idea of the pattern.
Some Observations on the Occipital Alpha Rhythm
Authors: Drever James
Published: March 2008

In order to test the hypothesis that the behaviour of the alpha rhythm is related to the kind of imagery used by different subjects, and in particular that the disappearance of the alpha rhythm during mental work is associated with the use of visual imagery, occipital EEG records were taken from groups of early blind, late blind, and sighted subjects during the performance of two spatial tests. Since the test scores differentiated between the groups it was argued that the performance probably involved a visual component. When the subjects were classified into the three suggested alpha-rhythm types, M, R, and P, the groups so obtained did not differ significantly from one another in terms of test scores. This was regarded as negative evidence so far as the hypothesis under investigation is concerned, especially since the alpha rhythm type supposedly associated with prevalently visual imagery was found most frequently among the blind.

It is clear that blindness is a complicating factor here as the amount and amplitude of alpha rhythm found in the blind records was less than in the case of the normal subjects. This, however, does not seem to invalidate the argument, but rather constitutes a problem for those who claim that absence of the alpha rhythm is associated with visual imagery. The hypothesis under investigation seems at present to be too simple and to need some reformulation before it will fit the facts.
Miscellanea: A Modified form of Wheatstone's Stereoscope
Authors: Grindley G. C.
Published: March 2008

An apparatus based on the principle of Wheatstone's mirror stereoscope is described. The main changes introduced are (a) that by the use of semi-transparent mirrors it is possible to arrange that the subject's eyes are correctly converged and accommodated at the beginning of each exposure, and (b) that the times of exposure of the two figures can be varied independently.
Apparent Fluctuations of a Sensory Threshold
Authors: Oldfield R. C.
Published: March 2008

An account is given of a method for the nearly continuous recording of sensory thresholds and other psycho-physical variables. Its application to the difference-threshold for sound-intensity is described. It is found that this threshold, so recorded, shows irregular fluctuations in time, excursions of up to 100 per cent, being commonly present. There is no prima facie indication of any regular periodicity in the fluctuations. No evidence was found of any general trend in amount of fluctuation throughout a half-hour period of observation. Nor, except in one subject, was there any tendency for the amount of fluctuation to increase or decrease over a series of six half-hour periods of observation. There are marked, and fairly consistent, differences between individual subjects as regards the amount and pattern of fluctuation. The possible locus and causes of these effects are briefly considered.
Central Inhibition—Some Refractory Observations
Authors: Elithorn Alick , Lawrence Catherine
Published: March 2008

The observation that the response to the second of two stimuli is delayed if a response has to be made to the first has led to the development of a theory of a central refractory state during which incoming stimuli cannot be elaborated. In the experiment reported here the two stimulus-response situations have been made as independent as possible, and under these conditions it is shown that this theory cannot be maintained in its present form. The concept that the central integrating mechanism readily becomes blocked by nay single stimulus is dismissed as nonproven and uneconomic. The present findings, however, confirm previous observations that some interference between the two situations may occur but indicate that this is not necessarily maximal immediately after the presentation of the first stimulus. It is tentatively suggested that the phenomena of central inhibition can be interpreted in terms of the interaction between the excitatory and inhibitory significance of the stimuli and the internal anticipatory set.
The Perception of Three-Dimensional Solids
Authors: Langdon J.
Published: March 2008

Arising from the discussion of differences between three- and two-dimensional perceptual objects in relation to current theories, an attempt is made to extend the traditional type of shape-constancy investigation into the realm of three-dimensional solids. For this purpose a specially constructed “solid” is made to undergo progressive physical changes of shape while being compared, under controlled conditions, with various stationary two-dimensional projections.

The results indicate that three-dimensional solids possess perceptual properties not shared by simple surfaces or representational projections. It is suggested that changes in the magnitude and sign of the constant errors obtained under certain conditions can be explained only on the assumption that subjects react to the stimulus in terms of some conceptual schema, or reference frame, involving mental processes other than those of perception.
Visual Illusion and Figural After-Effect, with and without Fixation
Authors: Summerfield Arthur , Miller Kenneth M.
Published: March 2008

An experiment, which was carried out with forty observers to investigate the effects of two conditions of observation, fixation and non-fixation, on the relative magnitudes of figural after-effect and immediate illusion is described. The combined inspection figure and test figure used in investigating after-effect displacements formed the figure used in investigating illusory displacements. An account is given of the apparatus used which enabled quantitative measurements of the displacements to be made by a production method. A second experiment on the magnitude of illusion and after-effect occurring with a slightly different figure and with fixation the only condition of observation is also briefly referred to.

The results of the experiments indicate (a) that illusory displacements exceed aftereffect displacements, contrary to Köhler and Wallach's (1944) non-quantitative observation, (b) that virtually no after-effect occurs in the absence of fixation as observation condition, (c) that while fixation is necessary to the production of after-effects, observation without fixation favours a significantly larger illusory effect.

It is concluded that, in spite of the similarities between after-effect and illusory displacements, differing mechanism must be postulated as underlying them, and, therefore, that neither Köhler and Wallach's theory nor Osgood and Heyer's (1951) theory of figural after-effect is capable of immediate extension to cover illusions.
The Warming-Up Effect in Recall Performance
Authors: Hunter Ian M. L.
Published: March 2008

Two experiments on recall are reported. In the first, 120 adults recall, in successive 3-rninute sessions, names which begin with a particular letter of the alphabet, a different letter being used in each session. The second experiment differs from the first in interpolating a 20-minute lecture between the first and second sessions. The major finding is that the performance of one recall task (e.g. recalling names which begin with. N) facilitates the performance of a subsequent and similar, but not identical, recall task (e.g. recalling names which begin with K), provided the two tasks occur within a relatively short time of each other. This facilitation has the characteristics of warming-up and suggests that recall may, if only for heuristic purposes, be regarded as a high-level skill. Two minor findings are reported which indicate problems for future investigation.
Access to knowledge in the digital era
Authors: KOSKINEN‐OLSSON Tarja
Published: March 2008

Access to knowledge is a critical issue when intellectual property rights are debated among governments in such fora as the World Intellectual Property Organization and the World Trade Organization. Scientific and scholarly materials became available online long before other types of copyright‐protected works, such as music and films. It is therefore particularly interesting to analyse how this specific field of publishing has adapted to the new digital landscape. Lessons can be learnt from related business sectors. Licensing is a key component in creating access, on terms and conditions that are fair and balanced for users in all parts of the world; this will encourage writing and publishing both now and in the future.
Extending the concept of publication: factbases and knowledgebases
Authors: SANDEWALL Erik
Published: March 2008

The concept of a ‘publication’ no longer applies only to printed works; information technology has extended its application to several other types of works. This article describes a facility called the Common Knowledge Library that publishes modules of formally structured information representing facts and knowledge of various kinds. Publications of this new type have some characteristics in common with databases, and others in common with software modules; however, they also share some important characteristics with traditional publications. A framework for citation of previous work is important in order to provide an incentive for contributors of such modules. Peer review – the traditional method of quality assurance for scientific articles – must also be applied, although in a modified form, for fact and knowledge modules. The construction of the Common Knowledge Library is a cumulative process; new contributions are obtained by interpreting the contents of existing knowledge sources on the Internet, and the existing contents of the Library are an important resource for that interpretation process.
Journals at bepress: new twists on an old model
Authors: PERCIALI Irene , EDLIN Aaron
Published: March 2008

In recent years academic journal publishers have explored a variety of new business models. The Berkeley Electronic Press (bepress), founded by professors in 1999, now publishes 39 electronic‐only journals. bepress's own model rests on three principles: improve, but do not break, the traditional journal; allow non‐subscribers to read articles as guests; and offer reasonable and sustainable prices to libraries. This model has resulted in steady growth. Even in the shifting landscape of open access, there remains a place for professional journal publishers who offer innovative improvements, traditionally qualified content, and reasonable prices.
Knowledge bases: improving the information supply chain
Authors: RAPPLE Charlie
Published: March 2008

In early 2006, information industry association UKSG commissioned a research report ‘to identify the new relationships and information exchange requirements … [necessary] to maximize the benefit of OpenURL linking'. Central to the efficient operation of the OpenURL is the knowledge base, which consists of data supplied by content providers including publishers. The report found that a lack of awareness on the part of many publishers of the OpenURL's capabilities and requirements is impacting the quality and timeliness of the data they provide to populate knowledge bases, and thus undermining the potential of this sophisticated technology. A programme of education and advocacy, particularly among smaller publishers, will be key to improving the efficacy with which OpenURL is currently implemented. The study's findings and suggestions will be taken forward by the KBART (Knowledge Bases And Related Tools) working group co‐chaired by UKSG and NISO; this article reviews the initial report and summarizes the planned remit and expected outcomes of the working group.