Training of fast tapping with reduction of kinaesthetic, tactile, visual and auditory sensations

Five subjects were trained to tap on a light Morse-key during nerve compression block. The training sessions lasted for 40 sec., with a 5 sec. rest after the first 20 sec. work period. The group learning curve reached 89.5 per cent. level of normal performance by the eighth training session. In the ninth, the testing session, subjects tapped with visual and auditory sense reduction superimposed on the kinaesthetic and tactile impariment of the training condition. Performance in the testing session reached 40.9 per cent. of normal.

The sixth subject was trained in the same task as the other five subjects, but the training condition included elimination of cues from all four sensory channels. He reached 79.09 per cent. of his normal tapping performance in the seventh session.

These results show that the motor skill of tapping can be relearned in the absence of kinaesthetic cues. Furthermore when the subject has no conscious knowledge of any peripheral sensory cues connected with the ongoing motor activity, learning can nevertheless take place. These findings lead to the hypothesis, that skilled motor activity can be monitored by central processes alone.

During the training sessions subjects showed a tendency of tapping in groups of gradually increasing length. It is hypothesized that increased number of taps forming a group gives an indication to the possible mode of action of these central processes.     

Programme for experiments on thinking

In remembering, items are used in the form in which they are alleged to have been perceived at some time in the past. In thinking, however, evidence is given and the essential character of the process is to move beyond this evidence, but in line with it, to something for which so far, no exact or complete perceptual basis is claimed.

From an experimental point of view the best approach is to consider thinking as a high level skill, and to design experiments in the light of what has been discovered during recent years about the learning, practice and achievements of skill on a psycho-motor level.

When this is done, it turns out that the thinking process can usefully be considered as one in which gaps are filled up in accord with specific evidence provided. The fundamental gap-filling processes are either of interpolation or of extrapolation.

In the present paper the methodology proposed is developed and illustrated in a preliminary manner.     

Early motion processes and the kinetic depth effect

It has been known for over 30 years that motion information alone is sufficient to yield a vivid impression of three-dimensional object structure. For example, a computer simulation of a transparent sphere, the surface of which is randomly speckled with dots, gives no impression of depth when presented as a stationary pattern on a visual display. As soon as the sphere is made to rotate in a series of discrete steps or frames, its 3-D structure becomes apparent. Three experiments are described which use this stimulus, and find that depth perception in these conditions depends crucially on the spatial and temporal properties of the display:

1. Depth is seen reliably only for between-frame rotations of less than 15°, using two-frame and four-frame sequences.

2. Parametric observations using a wide range of frame durations and inter-frame intervals reveal that depth is seen only for inter-frame intervals below 80 msec and is optimal when the stimulus can be sampled at intervals of about 40-60 msec.

3. Monoptic presentation of two frames of the stimulus is sufficient to yield depth, but the impression is destroyed by dichoptic presentation.

These data are in close agreement with the observed limits of direction perception in experiments using “short-range” stimuli. It is concluded that depth perception in the motion display used in these experiments depends on the outputs of low-level or “short-range” motion detectors.     

Dichoptic induction of Mccollough-type effects

If left-oblique and right-oblique black/white gratings are presented alternately to one eye, and unpatterned red and green fields are presented alternately to the other, orientation-sensitive chromatic after-effects are induced. With the colour-stimulated eye the hue usually seen on a test grating is complementary to that originally paired with its orientation, with the pattern-stimulated eye the hue is the same as that originally paired.

The experiments reported here show that: (a) the time course of decay of these chromatic after-effects (for each eye) fits approximately the same power law as that found for the normal McCollough effect; (b) analogous chromatic after-effects, opposite in the two eyes, can be dichoptically induced using pairs of stimuli other than gratings, such as dot patterns differing in magnification.

These results suggest that strongly coloured light in one eye can induce a weakly complementary bias in the colour-signalling system of the other eye, at a level peripheral to the site of the McCollough-type adaptation.     

Sexual exhaustion and recovery in the male rat

Twelve male rats were left with receptive females and allowed to copulate and ejaculate until they reached a criterion of “sexual exhaustion” They were then retested after 1, 3, 6 and 15 days of sexual inactivity. Following these observations males were tested once each day or once every other day and allowed to achieve a single ejaculation.

In the course of a period of unlimited access to the receptive female males usually need approximately 10 intromissions to produce the initial ejaculation, but successive ejaculations are produced by fewer and fewer intromissions. The time to recover from the effects of an ejaculation increases progressively as exhaustion is approached.

Very few animals copulate when tested 24 hours after sexual exhaustion. Considerably more recovery is evident in tests conducted after a 3-day rest, but it is not complete and rats are not capable of achieving as many ejaculations as they tend to achieve after longer periods of inactivity. As measured by ejaculation-frequency, the curve of sexual recovery is negatively accelerated and probably reaches asymptote after 7 to 10 days of rest.

Various other measures in addition to ejaculation-frequency support this conclusion. Males allowed to ejaculate once each day or every other day are somewhat less responsive than fully rested animals, but do not show any progressive loss in sexual excitability or capacity.

A working hypothesis is proposed to explain most of the findings. It postulates the existence of an Arousal Mechanism which is distinct from a Copulatory Mechanism. The ways in which these hypothetical mechanisms are affected by sexual performance and sexual rest arc discussed.     

The imaginaiy questionnaire

The experiment was designed to throw some light on the statistical problems in the analysis of questionnaire data. Previous work (unpublished) suggested that a simple choice response was partially determined by previous responses; and also that the nature of the determination was changed with changing length of series. A “null” experiment was devised in the form of a questionnaire without any questions, and the distribution of responses was studied with respect to the problems formulated.

The observations are discussed in three sections.

In the statistical discussion an alternative meaning to overall association or dissociation is advanced. This: relates association or dissociation to human behaviour in the serial response situation, rather than to qualities of the questionnaire. It is further suggested that association between specific, questions should be tested against the association in the whole questionnaire, and an appropriate treatment is indicated.

The observations depart from statistical randomness in certain ways. Answers made up almost entirely of one form of response are given less often than would be expected. Long sequences of the same type of response are relatively infrequent, and sequences of alternation of response are also rare. As the material is “null” it implies that the human concept of randomness differs from the statistical concept.

An attempt is made to define the human concept of randomness. It appears that a series of responses which has a pattern, or for which the subject can postulate a simple “cause” will not be accepted as random by the human subject. This raises problems of a perceptual and cognitive nature. It also has a bearing on the design of questionnaires. or experiments involving serial responses.     

Speech production and the predictability of words in context

The purpose of the experiments was to examine the function of hesitation pauses in speech. Pauses were conceived of as anticipating increase of information in subsequent speech and as involving acts of choice.

This hypothesis was tested by relating the incidence of pauses within sentences to the transition probabilities of the words constituting them. Estimates of these probabilities were obtained experimentally by an adaptation of Shannon's guessing technique and were based on reverse as well as forward guessing. The hypothesis was borne out by the facts; hesitancy in speech was shown to be closely related to uncertainty of prediction (entropy) and fluency of utterance to redundancy. These results are shown to be in line with the facts of language statistics. Their theoretical implications for the concept of information and for understanding the processes of speech organization is discussed.     

The apparent length of a line as a function of its inclination

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.     

Stimulus Intensity and Attention in Relation to Learning Theory

Three experiments are described which test the hypothesis that the more intense of two stimuli will, ceteris paribus, be more likely to receive attention. It is assumed that an objective behavioural manifestation of attention to a given stimulus is a preference for responding to it rather than to another which is present at the same time.

In all three experiments, successions of pairs of visual stimuli interspersed with single stimuli were presented to the subject, and he was instructed to respond to either (by pressing its corresponding morsekey), but not both, in the case of the pairs. The first two experiments reveal significant tendencies to respond to the larger and the brighter stimulus respectively. In the third experiment, there was a tendency, but a statistically insignificant one, to respond to a constant rather than to a flickering stimulus.

It is shown that the attraction of attention by a more intense stimulus follows from Hull's system with the addition of his new variable, “stimulus-intensity dynamism (V),” and it is suggested that it may thus be possible to add attention to the phenomena that can be integrated with an objective behaviour theory.     

Asymmetry of perception of size between the right and left hands in normal subjects

A method of measuring the perception of size in the hands was applied to 4 0 righthanded and 40 left-handed normal subjects.

It was found that objects of equal size held simultaneously in each hand tend t o be judged to be unequal, and that, in the majority of subjects, the object held in the doniinant hand is perceived to be the smaller.

These results are discussed in the light of previous work, and some reference is made to the examination of pathological cases.     

Book reviews and books received

Maurice North: The Secular Priests: Psychotherapists in Contemporary Society. London: Allen and Unwin, 1972. £3.75.

Department of Education and Science: Careers Education in Secondary Schools. Education Survey 18. London: HMSO, 1973. 68p.

Audrey Newsome, Brian J. Thorne and Keith L. Wyld: Student Counselling in Practice. London: University of London Press, 1973. £3.00 hardback, £ 1.50 paperback.

Peter Righton (ed.): Counselling Homosexuals. London: Bedford Square Press, 1973. 30p.

James Mann: Time-Limited Psychotherapy. Cambridge, Massachusetts: Harvard University Press, 1973. £3.20.

Ken Williams: The School Counsellor. London: Methuen, 1973. £2.00 (hardback); 95p (paperback).

A. G. Watts: Diversity and Choice in Higher Education. London: Routledge and Kegan Paul, 1972. £4.00.     

Retroactive raising of a sensory threshold by a contralateral stimulus

In an experiment designed to extend Howarth and Treisman's recent observations on the lowering of the visual and auditory threshold produced by a warning stimulus, it has been found that the threshold to electrical stimulation of one forearm is raised by a similar stimulus on the other forearm. As in the earlier experiments the “warning” was effective if it came 100 millisec. before or after the threshold stimulus. The effect increased with increasing warning strength over the range of five near-threshold strengths used.

These results appear to be inconsistent with the explanation previously proposed to account for the retroactive lowering of threshold. This suggested that the warning was acting simply as a marker, reducing the subject's uncertainty as to when the stimulus was coming. The fact that the rise in threshold was also induced retroactively shows that some interaction must be occurring in the central processes concerned in perception, and that it cannot be explained in terms of attenuation of the afferent volley.     

The amount seen in brief exposures

The experiments reported are a series of attempts to test the consequences of assuming that a subject exposed to briefly presented tachistoscopic information does not have access to a visual image. The partial report procedure is examined under several conditions with the letter row cues immediately following stimulus exposure, and at different levels of cue delay.

The results of eye movement monitoring, and of instructing subjects where to look, agree with the guessing data of a previous experiment in showing a sharp decline in the number of letters correctly reported when the subject is looking at the wrong row, in conformity with the anticipative selection hypothesis. The result of varying the subject's uncertainty about what is to be reported is to vary the slope of the delay curve; with the implication that inefficient strategies of rehearsal, rather than visual image decay, are responsible for the reported delay effects.     

The effects of repeated retesting: III. further experiments and general conclusions

This is the third of a series of papers dealing with the effects of repeated retesting on intelligence test scores. It comprises an account of two further experiments, and a discussion of the four so far performed, since each throws light on the results of the others and it is their joint interpretation which is thought to be of value.

The two earlier experiments consisted in repeated testing of a group of W.E.A. students and a group of mentally defective boys by an intelligence test (AH 4) designed for an unselected population. In the two later experiments, a group of Technical College students and a group of Naval Ratings were repeatedly tested on another intelligence test (AH 5), designed for a population of high-grade intelligence, such as university students. Examination of all the results confirms the artificiality of the “ceiling effect” which was suspected in the first experiment; it suggests that, given sufficient scope, subjects of all levels of intelligence would, with repeated trials on the same test, continue to improve their score up to and beyond 10 testing; and that, given comparable opportunity, subjects with initially higher scores will tend to improve more than those with initially lower scores. All these results concern short-term experiments with testing at weekly intervals.

The four sets of results considered jointly indicate that conclusions on these problems should be drawn only in terms of the relation between the level of the test and that of the group tested: this offers some resolution of the conflicting findings of earlier investigators.     

Temporal structure of letter groups and span of perception

The span of perception for letter groups depends on number of letters presented, length of presentation and structure of the groups. The experiment reported varied the temporal structure of the groups, leaving the total number of letters constant. Groups of 12 letters were presented as a whole or in two or more successive “units.” The total time of presentation was 1-5 sec. In the first experiment each unit was visible until the next appeared, in the second experiment units were visible only during 1/4 sec., although intervals between successive units were kept constant.

The following conclusions emerged:

(a) The visual presence of units did not affect the reproduction for durations over 0.25 sec., except in the 12-letter presentations.

(b) 2×6 letters gave better results than either simultaneous presentation or other divisions; temporal separation was 0.75 sec.

(c) Higher order approximations to Dutch have more influence on 3 × 4, 2 × 6 and 1 × 12 letters than on 4 × 3 and 6 × 2 letters.

(d) A serial order effect exists: central units are reproduced less well than first and last units.

It is suggested that handling a fixed amount of information within a fixed period is limited on the one hand by confusion between simultaneous elements and on the other hand by the interaction between successive units presented too rapidly to allow for proper operation of immediate memory.

The difference between span of perception and span of memory is stressed.     

Evidence of a single-channel decision mechanism limiting performance in a serial reaction task

An experiment is described in which the subject sat facing a display of two neon bulbs. When the left-hand bulb lit he pressed a key under his left hand, and when the right hand bulb lit he pressed a key under his right hand. The left-hand bulb gave brief flashes at random intervals averaging about 4 sec. The right-hand bulb gave a brief flash at regular intervals of about 4 sec.

The experiment repeats (the author believes for the first time) certain essential conditions of Vince's (1948, 1950) experiments and, following detailed scrutiny of every pair of responses, is taken as evidence for the following statements:—

(a) The response to a signal arriving during the reaction time to a former signal will be delayed by an amount approximately equal to the time elapsing between the arrival of the signal and the end of the reaction time to the former signal.

(b) An exception to this may occur when two signals arrive close together. In this case the two signals may be responded to as a single group.

(c) Delays can be occasioned by the monitoring of responses as well as by reactions to signals.

(d) “Grouping” of signal and monitoring may occur when a signal arrives close to the beginning of the movement made in response to a previous signal.

A survey is made of current theories in this field and suggestions given for further research.     

Book reviews

Contemporary psychology Experiments: Adaptations for Laboratory. By John Jung and Joan Bailey. London and New York: Wiley. 1966 Pp. xiii + 155. 238.

A Textbook of Psychology. Second Edition. By D.O. Hebb. Philadelphia and London: W.B. Saunders & Co. 1966. Pp xvi + 353. Pound2.

Behaviour Therapy Techniques: A Guide to the Treatment of Neuroses. By Josweph Wolpe and Arnold A. Lazarus. Oxford and London: Pergamon Press. 1966. Pp. ix + 198. 21s.

Motivated Learning: a Developmental Study from Birth to the Senium. By Miriam E. Hebron. London: Methuen. Methuen's Manuals of Modern Psychology. 1966. Pp. 264. 35s.

Human Brain and Psychological Processes. By A.R. Luria. Translated by Basil Haigh. New York and London: Harper & Row. 1966. Pp.xix + 587. £5 $14.50.

Higher Cortical Functions in Man. By A. R. Luria. Translated by Basil Haigh. London: Tavistock Publications. 1966. Pp xvi + 513. £6 6s.

Productive Thinking. By Max Wertheimer. Edited by Michael Wertheimer. social science Paperbacks. London: Tavistock Publications. 1966. Pp xvi + 302. 30s.

Problem Solving: Research Method and Theory. Edited by B. Kleinmuntz. London and New York: Wiley. 1966. Pp. ix + 406. 53s.

Human Conceptual Behavior. By Lyle E. Bourne, Jr. Boston: Allyn and Bacon. 1966. Pp. viii + 139. $2.50.

Attraction and Hostility. An Experimental Analysis of Interpersonal and Self Evaluation. By albert Peptone. London: Tavistock Publications. 1966. Pp. ix + 234. 30s.

Ability Structure and subgroups in Mental Retardation. By John Clausen. London: Macmillan. Washington: spartan Books. 1966. Pp. viii + 208. 80s.

The Biologiv Basis of Schizophrenia. By Jon L. Karlsson. springfield. Illionois: Thomas. 1966. Pp.xi + 77. $4.75.

Psychology for Psychiatrists. By C.G. Costello. London: Commonwealth and Unversity Library, pergamon Press. 1966. Pp. 328. 25s.

Science and theory of Psychoanalysis. Edited by Irwin G. Sarason. London: Van Nostrand. Insight Book No. 26. 1965. Pp xiii + 205. 14s.

Aspects of Learning and Memory. Edited by D. Richter. London: heinemann. 1966. Pp. x + 185. 35s.

The Spiral After-Effect. By Harry C. Holland. London: pergamon. 1965. Pp.xii + 99. 35s.

Dynamics of Response. By J.M. Notterman and D.E. Mintz. London and New York: Wiley. 1965. Pp. 277. 70s.

Contrary Imaginations: A Psychological Study of the English Schoolboy. By Liam Hudson. London: Methuen. 1966. Pp. vii + 181. 25s.

The Structure of Association in Language and Thought. By James A. Deese. London: Oxford University Press: Johns Hopkin Press. 1960. Pp. xiii + 216. 52s.

A source Book in the History of Psychology. Edited by R. J. Herrnstein and E.J. boring. London: Oxford University Press; Harvard University Press. 1965. Pp. xvii + 636. £5.     

On the role of outline shape and word-specific visual pattern in the identification of function words: None

A common assumption in the reading literature is that function words are often identified wholly or in part on the basis of outline shape and/or word-specific visual pattern. This assumption was examined in three perceptual identification experiments, a speeded oral reading experiment, and in a lexical decision task where the visual pattern of function words and control items (content words, non-words and control strings) was systematically distorted by cAsE alTeRnA-tIoN. In all five experiments distortion failed to impair performance more on functors than on various control items. This result is argued to be inconsistent with the view that outline shape and word-specific visual pattern typically play a role in the identification of isolated function words.

Shape distortion impaired function words less than controls in perceptual identification, but impaired function and content words equally in speeded naming and lexical decision. These contrasting effects of shape distortion are discussed in terms of a distinction between the uptake of information (lexical access) and phenomenal perception.     

Book reviews

Aggression: a Social Psychological Analysis. By Leonard Berkowitz. London: McGraw-Hill Book Co. Inc. 1962. Pp. xv + 361. 62s.

Cumulative Record. By B. F. Skinner. London: Metbuen. 1962. Pp. × + 426. 50s.

Psychology Through Experiment. Edited by G. Humphrey. London: Methuen. 1963. Pp. 307. 30s.

Behaviour and Awareness. Edited by C. W. Eriksen. Durham, N.C.: Duke University Press and London: Cambridge University Press. 1962. Pp. vi + 158. 28s.

Motivation and Emotion. By Paul Thomas Young. New York and London: Wiley. 1961. Pp. xxiv + 648. 86s.

The Assessment of Pain in Man and Animals. Edited by C. A. Keele and Robert Smith. London. U.F.A.W. (The Universities Federation for Animal Welfare). Distributing agents: E. & S. Livingstone. 1963. Pp. xi + 323. 30s.

A Study in Behaviour. By S. A. Barnett. London: Methuen. 1963. Pp. xvi + 288. 45s.     

Further studies in the perception of a changing shape

Koffka's hypothesis of “invariant relation” holding between tilt and perceived shape of an object is discussed from the standpoints both of logical tenability and of experimental findings.

After discussion of certain shortcomings in the method of investigation devised by Stavrianos, two experiments are suggested, the first, of a simple character, intended to follow out in practice the hypothetical conclusions of Koffka's argument, the second to test the hypothesis under conditions which attempt to ensure the preservation of the perceptual object throughout the arc of tilt. For this purpose subjects attempt to match two shapes, one of which is stationary whilst the other revolves at a constant speed. The comparison shapes cover the range of the possible arc of tilt.

The results of the first experiment, whilst appearing to contradict the requirements of the hypothesis, are by no means conclusive. The second experiment, though not absolutely conclusive, gives little support to Koffka. The main conclusion drawn is that there occur non-systematic variations in perceptual constancy throughout the arc of tilt. These are of a phasic character and are qualitatively different from results obtained by matching stationary shapes. There appears to be no simple function which would result in exhibiting a uniform constancy value for the entire arc of orientation.