Sanford Goldstone

JUDGMENT OF FILLED AND UNFILLED DURATIONS: INTERSENSORY FACTORS

Previous studies have shown a consistent intersensory difference in absolute judgments of the duration of continuous auditory and visual inputs. More visual than auditory clock time was judged equivalent to specific temporal concepts. Two experiments investigated this intersensory phenomenon further by comparing the judgments of filled auditory and visual durations with the estimation of unfilled intervals bounded by discrete lights and sounds. Auditory durations were judged longer than visual for the filled and unfilled conditions, and filled auditory durations were judged longer than unfilled auditory intervals The intersensory difference in time judgment was independent of stimulus pattern while the filled-unfilled difference was dependent upon sense mode, order effects and internal temporal standard. Stimulus properties must be considered when interpreting the results of time judgment research.

Time Judgment: A Comparison of Filled and Unfilled Durations:

Sense mode ( 1 ), anchors ( 2 ) , and psychophysical method ( 3 ) influence time judgment. This experiment explores the possibiliry that temporal estimates of filled and unfilled durations would differ; the presence or absence of stimulation during the interval may be a relevant factor in time judgment. Two groups of 27 Ss each were presented an ascending and descending series of both filled durations of light and unfilled durations bounded by light flashes with order counterbalanced. The light source was a small red neon glow tube of comfortable brightness. Each filled and unfilled duration was judged by S as more or less than his concept of one clock second. A filled and unfilled Second Estimation Point (SEP) was derived from these judgments ( 2 ) . Since no order effects were found, the two groups were combined and filled and unfilled SEPs were compared with the Wilcoxon matched pairs rest. Filled durations (Mdn SEP, .81 sec.) were judged significantly longer (P < ,001) than unfilled durations (Mdn SEP, 1.00 sec.). More unfilled clock time was judged equivalent to the same temporal concept than filled clock rime, reflecting greater relative overestimation of the filled input. It is clear chat there are differences in apparent duration dependent upon whether S judges time that involves the presence or absence of stimulation. This finding should be investigated further using other sense modes, ranges of durations, and psychophysical methods.

The effects of haloperidol upon temporal information processing by patients with Tourette's syndrome

Tourettes syndrome patients treated successfully with haloperidol, untreated patients, and healthy controls were studied with tests of temporal discrimination and measures of transmitted information shown previously to be sensitive to brain dysfunction. Untreated patients showed no impairment of temporal processing while those treated with haloperidol showed significant deficit in amount of transmitted information comparable to prior studies of brain syndromes.

THE HUMAN CLOCK: A FRAMEWORK FOR THE STUDY OF HEALTHY AND DEVIANT TIME PERCEPTION*

This presentation represents an opportunity to reflect on a decade of research into human time perception, which began with a simple psychophysical experiment and a simple hypothesis about the relationship between schizophrenia and perceived duration. The finding that schizophrenic patients overestimated short auditory durations more than healthy controls (Lhamon & Goldstone, 1956) led to continued investigation of the effects of an assortment of organismic and contextual factors upon time perception. Each experiment increased the complexity of the problem, and after ten years and almost 10,000 subjects, the mysteries of human temporal functioning had multiplied more rapidly than solutions. This program of research began with a view of the human clock as a simple hourglass; the hourglass was replaced by an unpictured clock of matchless complexity. The returns of early experimentation made it clear that understanding the psychopathology and psychopharmacology of time perception required extensive baseline research with healthy adults and children, to uncover the relevant stimulus and organismic factors that determine the level and stability of temporal functioning. Experiments required healthy adults and children, mentally ill and retarded subjects, and people taking psychotropic drugs to: 1. render single stimuli judgments of perceived time using category scaling techniques; 2. provide intramodal and crossmodal successive comparisons of auditory and visual durations; 3. produce auditory and visual durations upon command; and 4. provide intramodal reproductions of auditory and visual durations. The range was limited to .15 to 4.00 sec., and stimulus and response conditions were systematically varied. Measures of subjects’ average temporal response and intrasubject response variability were obtained for every duration perceived and for all conditions of stimulation. Many factors contributed to the level and variability of temporal response, showing that time perception is dependent upon the various temporal problems posed by the different psychophysical methods, the receptor system stimulated, the arrangements and patterns of stimulation, the physical properties of stimuli, the characteristics of anchoring conditions within and across sense modes, the nature of the temporal standard, and the constraints of response requirements. Temporal levels and stability were usually a function of interactions of several stimulus and organismic

PROPERTIES OF SOUND AND THE AUDITORY-VISUAL DIFFERENCE IN TIME JUDGMENT.

Sound durations are judged longer than light durations, and this intersensory difference in time judgment is independent of psychophysical method, range of durations, response scale, and several scimulus characteristics such as wave length of light, pure-tone frequency of sound, and intensity of both kinds of inputs ( 1, 2, 3 ) . The present study explored the possibility that this auditoryvisual difference was due to the exclusive use of pure tones in previous investigations by using a white sound-white light comparison. Forty adult Ss made single stimulus judgments of the duration of white lights and sounds of comfortable intensity, ranging from .15 to 1.95 sec., with a .30-sec. interval according to the method of constant stimuli. Each S judged along 9-category scales of longness-shortness (i.e., middle category 5 was mediam) or in comparison with Ss concept of one clock second (i.e., middle category 5 was equal) . All Ss judged blocks of auditory and visual durations, using one of the rwo response scales, and sense mode order was counterbalanced. A detailed account of apparatus, experimental design and methods is reported elsewhere ( 2 , Exp. 11). A trend test [an extended Lindquist Type VI design ( 4 ) ] revealed a significant difference due to sense mode (F = 40.32; df = 1/520. P < .001), confirming the auditory-visual difference; white sounds were judged longer than white lights. Comparison of these results with an identical study employing pure tones and the same light source (i.e., 2 , Exp. 11) indicated an absence of a pure tonewhite noise difference and an intersensory difference of the same magnitude. This experiment provides further evidence for a stable, easily demonstrated auditory-visual difference in rime judgment characteristic of the human species. All modifications of stimulus characteristics and arrangements failed to alter the fact that sounds are lu~lgetl longer than lights (1.2, 3 ) .

Time estimation and psychopathology

Several experiments ( 1, 2, 3 ) have demonstrated that schizophrenic Ss overestimate auditory durations when comparing inputs presented with a modified method of limits procedure and an arithmetic step interval with their concept of one clock second. Patient groups identified shorter durations as equivalent to one second. The present study extended this investigation to other psychiatric populations and a chronically ill non-psychiatric population in order to explore the possibility that the earlier findings were not specific to schizophrenia. Ss were 163 healthy people, 35 patients hospitalized with depression, 10 patients hospitalized with anxiety reaction, and 35 chronically ill, hospitalized patients from medical and surgical wards in the Houston Veterans Adrninistration Hospital. The method (1, 2, 3 ) required S to judge ascending and descending series of auditory durations as more or less than one clock second. A Second Estimation Point (SEP) was derived from these judgments. Populations were compared with the Mann-Whitney test and no significant difference between any two of the populations was obtained. The median SEP values for all groups, healthy, .66 sec., depression, .54 sec., anxiety, .77 sec., and non-psychiatric chronic illness, .63 sec., were considerably longer than those obtained previously (1, 2, 3 ) with schizophrenic populations using the same method. It is suggested that the shorter SEP with schizophrenia is specifically related to the disease and not to chronic illness or psychiatric disorder in general.