A jiffy clock for the Apple IIc,II+, and IIe with a mouse

A “jiffy clock” is presented for the Apple lIc or other Apple II having Apple’s mouse card. The clock allows timing of events to tenths of a second, and is read from BASIC. A convenient elapsed timer function is provided as well.     

Why 'Sounds Are Judged Longer Than Lights': Application of a Model of the Internal Clock in Humans

Three experiments, using temporal generalization and verbal estimation methods, studied judgements of duration of auditory (500-Hz tone) and visual (14-cm blue square) stimuli. With both methods, auditory stimuli were judged longer, and less variable, than visual ones. The verbal estimation experiments used stimuli from 77 to 1183 msec in length, and the slope of the function relating mean estimate to real length differed between modalities (but the intercept did not), consistent with the idea that a pacemaker generating duration representations ran faster for auditory than for visual stimuli. The different variability of auditory and visual stimuli was attributed to differential variability in the operation of a switch of a pacemaker-accumulator clock, and experimental datasuggested that such switch effects were separable from changes in pacemaker speed. Overall, the work showed how a clock model consistent with scalar timing theory, the leading account of animal timing, can address an issue derived from the classical literature on human time perception.     

Walking Before and During a Sea Voyage

Stationary and moving surfaces impose different constraints on walking. In this study we investigated within-participants differences between walking on a ship before (at the dock) and during (at sea) a sea voyage. Four individuals participated in the study. While on the ship they wore a tri-axial accelerometer (ActiGraph GT3X+; ActiGraph LLC, Pensacola, FL) on their waists. Activity data were sampled at 30 Hz. Data were collected on the day before the voyage began and on several days at sea. The number of steps per day was greater at the dock than at sea. The net resultant force per day also was greater at the dock than at sea. However, resultant force per step was greater at sea (79.97 ± 8.50 vector magnitude counts/step) than on land (62.94 ± 10.03 vector magnitude counts/step). In addition, we observed variations in resultant force per step across days at sea. Ship motion decreased overall activity but increased the force per step.     

How to obtain near-millisecond precision on the IBM PC with visual stimuli not exceeding one printed line

Techniques are described for using an IBM PC equipped with a mouse to investigate the reading of character sequences of maximally one display line. Solutions are given to problems that arise and derive from the PC’s real-time clock, the slowness of the display, and registration of input during a test session. A program for using the techniques to study asynchronous perception of printed words is described, and a demonstration program is provided as an appendix.     

Children's perceptions of occupational sex stereotypes

Female and male children ranging in age from 21/2 to 8 years were asked to indicate for each of 10 occupations whether a male or a female adult would be most likely to engage in the occupation. Five traditionally male and five traditionally female occupations were presented in random orders. The results indicated that the children at each age level made a significant distinction between the two occupational groupings, with the extent of the distinction increasing with age level. There were no significant effects involving the sex of the children. The results were interpreted as indicating the learning of adult stereotypes concerning the sex appropriateness of occupations by children as young as 21/2; years old. The potential implications of this sex stereotype for actual career decisions and aspirations were discussed.The authors would like to express their appreciation to the principal, M. Brady Thomas, and the teachers at Hickory Grove Elementary School for their help during the study. The order of authorship was randomly determined.     

The role of cognitive factors in the rod-and-frame effect

We compared the contribution and the effectiveness of modulating the orientation perception of two types of visual information: the visual frame and the visual polarity of objects. In experiment 1, we examined the effect of a square frame, a mouse, an elephant, and a map of France on the apparent vertical. In the upright position, despite the presence of tilted individual component features, the visual objects had no illusory visual tilt effects. When tilted, these objects had a substantial effect on the direction that appeared to be vertical. However, rod-setting errors were smaller in the inducing objects than when observed with the frame display. In the second experiment, the results of experiment 1 were replicated with a meaningful circular contour--a porthole and a clock. The presence of the external circular contour did not abolish the illusion on the apparent vertical. Moreover, in experiment 3, a clock whose numbers were displaced and not tilted--to avoid the possible tilt influence of visual cues--was also able to deflect the subjective visual vertical. This finding suggests that through top-down processing shapes can act as a framework which serves as a reference influencing the perceived orientation of the inner objects.     

Structuring temporal sequences: Comparison of models and factors of complexity

Two stages for structuring tone sequences have been distinguished by Povel and Essens (1985). In the first, a mental clock segments a sequence into equal time units (clock model); in the second, intervals are specified in terms of subdivisions of these units. The present findings support the clock model in that it predicts human performance better than three other algorithmic models. Two further experiments in which clock and subdivision characteristics were varied did not support the hypothesized effect of the nature of the subdivisions on complexity. A model focusing on the variations in the beat-anchored envelopes of the tone clusters was proposed. Errors in reproduction suggest a dual-code representation comprising temporaland figural characteristics. The temporal part of the representation is based on the clock model but specifies, in addition, the metric of the level below the clock. The beat-tone-cluster envelope concept was proposed to specify the figural part.     

The influence of stimulus array on training of a speeded response

We conducted two experiments to study the training of speeded responses to stimuli in a clock face array. Participants were trained on one clock face and later tested on either the same or a different clock face. The clock faces varied along 3 dimensions of change (left-right flip, up-down flip, and 180 degrees rotation). Skill acquisition was reflected in decreases in overall, initiation, and movement response times in the training and test phases except that movement time reached an asymptote during training and did not decrease further during test. Test performance was best when training and test used the same clock face and worst when the training to test change involved an up-down flip. The transition to different clock faces was consistent with an interpretation based on the violation of expectations about target positions acquired during training. Consistent trial-by-trial feedback led to better initiation time but not movement time during training than periodic feedback, but this effect did not persist into the test phase.     

自我损耗对基于时间前瞻记忆的影响

采用Stroop任务和前瞻记忆双任务实验范式,比较不同自我损耗条件对被试基于时间前瞻记忆（TBPM）的影响,及其对TBPM的加工阶段和成分的作用。然后通过添加外部时钟监控条件,探讨外部时钟是否可以减少自我损耗对TBPM的消极影响,以及自我损耗对时钟监控情况的作用。结果表明：（1）在内部控制条件下,自我损耗会严重影响TBPM的表现,高损耗组的TBPM成绩显著低于低损耗组,另外,自我损耗主要干扰前瞻记忆的前瞻成分和TBPM的第三个加工阶段。（2）在外部控制条件下,自我损耗没有降低TBPM的表现,说明外部时钟可以降低自我损耗对TBPM的消极影响。（3）自我损耗使个体呈现出不同的时钟监控模式,且邻近目标时间内的时钟监控次数与TBPM成绩呈显著正相关。     

Origines et développement des théories d’horloge interne du temps psychologique

The article describes the origins and development of internal clock theory. The history is traced via body temperature studies in the 1920s and 1930s, with input from 19th. century and early 20th. century psychophysics, through to the model of Treisman (1963). This model derived timed behaviour from an interaction of internal clock, memory store, and comparison processes. A successor to Treisman's model was the scalar expectancy theory (SET) of Gibbon and colleagues (1984). The origins of SET in animal Psychology are described, as is its application to human timing (in the early 1990s), in particular recent work on the operation of the internal clock itself. Finally, a discussion of some recent developmental studies of timing illustrates both how internal clock models have been applied, and how modern research may require a reconceptualization of the operation of classical internal clock models.     

Clock control of human performance on avoidance and fixed-interval schedules

The avoidance and fixed-interval performances of human subjects were studied in two experiments. Addition of time-correlated stimuli (added clock) improved behavioral efficiency, since response rates decreased without decreases in reinforcement rates. Response-dependent display of the clock maintained a second, observing response and reductions in clock duration weakened such observing behavior. Generally, the reinforcing properties of the clock were more apparent with the avoidance than with the fixed-interval schedule, a finding attributed to temporal cues already provided by delivery of the fixed-interval reinforcers. Reduced rates of the main response when the clock was dependent on an observing response were more than offset by rates of the observing response in the majority of subjects. Thus, the results do not support an interpretation of the reinforcing properties of added clocks simply in terms of work reduction.     

Processing of visually presented clock times

The encoding and representation of visually presented clock times was investigated in three experiments utilizing a comparative judgment task. Experiment 1 explored the effects of comparing times presented in different formats (clock face, digit, or word), and Experiment 2 examined angular distance effects created by varying positions of the hands on clock faces. In Experiment 3, encoding and processing differences between clock faces and digitally presented times were directly measured. Same/different reactions to digitally presented times were faster than to times presented on a clock face, and this format effect was found to be a result of differences in processing that occurred after encoding. Angular separation also had a limited effect on processing. The findings are interpreted within the framework of theories that refer to the importance of representational codes. The applicability to the data of Bank's semantic-coding theory, Paivio's dual-coding theory, and the levels-of-processing view of memory are discussed.     

Fixed-interval performances with added stimuli in monkeys

The performance of two monkeys, on fixed-interval schedules, was examined with a visual, an auditory and a combined auditory-visual clock. The clock, a voltmeter and/or a variable frequency tone, produced performances different in many aspects from those recorded earlier with pigeons. Instead of the sustained high rates of responding at the optimal settings of the clock, the monkey's rates of responding were often extremely low even though a limited-hold contingency was utilized.     

Specificity effects in training and transfer of speeded responses

In 3 experiments, participants, on signal, moved a cursor from a central position to 1 of 8 numerically labeled locations on the circumference of a clock face. Movements were controlled by a mouse in 1 of 4 conditions: vertical reversal, horizontal reversal, combined reversals, or normal (i.e., no reversals). Participants were trained in 1, 2, or 3 of these conditions and were tested 1 week later with either the same or a different condition. There were improvements across training and perfect retention across the delay. There was little or no transfer, however, even when training involved combined reversals or multiple conditions. These results illustrate severe specificity of training and are interpreted in terms of acquired inhibition of normal responses.     

Developmental progression of clock face drawing in children.

The clock drawing test has been routinely administered by many neuropsychologists as part of their testing battery with the adult population. Our study investigated the development of clock face drawing in normal children ages 6 to 12 years. Conceptualization of time and construction of the clock face were assessed by an adapted scoring system developed as part of the investigation. As a group, the results indicated an upward progression with regard to the concept of time through age 8 and clock construction through age 12. Results further demonstrated that number reversals were more frequent among left-handers but were no longer evident by age 7 regardless of handedness. It also was determined that left visuospatial neglect specific to the upper quadrant was relatively common in 6- and 7-year olds but not evidenced by age 8. Given the pattern of the findings, it is likely that the neglect was secondary to poor planning and not a visuo-spatial deficit. In general, development of clock face drawing most closely paralleled that of frontal lobe maturation. Implications of these findings and the usefulness of clock face drawing with the pediatric population are presented.     

Developmental Progression of Clock Face Drawing in Children

The clock drawing test has been routinely administered by many neuropsychologists as part of their testing battery with the adult population. Our study investigated the development of clock face drawing in normal children ages 6 to 12 years. Conceptualization of time and construction of the clock face were assessed by an adapted scoring system developed as part of the investigation. As a group, the results indicated an upward progression with regard to the concept of time through age 8 and clock construction through age 12. Results further demonstrated that number reversals were more frequent among left-handers but were no longer evident by age 7 regardless of handedness. It also was determined that left visuospatial neglect specific to the upper quadrant was relatively common in 6- and 7-year olds but not evidenced by age 8. Given the pattern of the findings, it is likely that the neglect was secondary to poor planning and not a visuo-spatial deficit. In general, development of clock face drawing most closely paralleled that of frontal lobe maturation. Implications of these findings and the usefulness of clock face drawing with the pediatric population are presented.     

Some effects of response-dependent clock stimuli in a fixed-interval schedule

Two experiments studied the effects of brief response-dependent clock stimuli in fixed-interval schedules of reinforcement. In the first experiment, two pigeons were exposed to a fixed-interval schedule. Two conditions were compared. In both conditions each peck on the key produced a brief stimulus. In one condition, pecks produced a different stimulus in successive sixths of the interval. This was the clock condition. In the other condition, the same stimulus was produced throughout the interval. Response rates were lower and the pause after reinforcement was longer in the clock condition. In the second experiment, a two-key optional clock procedure was used. Responding on the clock key produced one of three stimuli correlated with the three successive minutes of a fixed-interval schedule. A response on the other key produced grain at the end of the 3 min. When the final stimulus was removed from the situation and pecking produced nothing during the third minute, responding to the clock key declined to a very low rate. When the first two stimuli were removed and the third one replaced, responding to the clock key was resumed.     

Clock drawing in spatial neglect: A comprehensive analysis of clock perimeter, placement, and accuracy

Clock drawings produced by right-brain-damaged (RBD) individuals with spatial neglect often contain an abundance of empty space on the left while numbers and hands are placed on the right. However, the clock perimeter is rarely compromised in neglect patients' drawings. By analysing clock drawings produced by 71 RBD and 40 healthy adults, this study investigated whether the geometric characteristics of the clock perimeter reveal novel insights to understanding spatial neglect. Neglect participants drew smaller clocks than either healthy or non-neglect RBD participants. While healthy participants' clock perimeter was close to circular, RBD participants drew radially extended ellipses. The mechanisms for these phenomena were investigated by examining the relation between clock-drawing characteristics and performance on six subtests of the Behavioral Inattention Test (BIT). The findings indicated that the clock shape was independent of any BIT subtest or the drawing placement on the test sheet and that the clock size was significantly predicted by one BIT subtest: the poorer the figure and shape copying, the smaller the clock perimeter. Further analyses revealed that in all participants, clocks decreased in size as they were placed farther from the centre of the paper. However, even when neglect participants placed their clocks towards the centre of the page, they were smaller than those produced by healthy or non-neglect RBD participants. These results suggest a neglect-specific reduction in the subjectively available workspace for graphic production from memory, consistent with the hypothesis that neglect patients are impaired in the ability to enlarge the attentional aperture.     

Adding drift to the decomposition of simple isochronous tapping: an extension of the Wing-Kristofferson model

The Wing-Kristofferson model (A. M. Wing & A. B. Kristofferson, (1973a, 1973b) decomposes the variance of isochronous finger tapping into 2 components: a central clock component and a peripheral motor component. The method assumes that there is no drift in the intertap intervals. A new method is introduced that further decomposes the clock component drift and drift-free clock variance. The method was studied through simulation and empirical analyses. Clock variance was the most prominent, followed by drift, and then motor variance. Individual and group differences were larger for the motor and drift variances than for the drift-free clock variance, so that group differences observed in the past may have been partially due to the failure to fully remove drift. The authors argue that the methods presented and extensions thereon show great promise in extending a method in wide use since 1973.     

Temporal preparation decreases perceptual latency: Evidence from a clock paradigm

A clock paradigm was employed to assess whether temporal preparation decreases the time to detect the onset of a stimulus—that is, perceptual latency. In four experiments participants watched a revolving clock hand while listening to soft or loud target tones under high or low temporal preparation. At the end of each trial, participants reported the clock hand position at the onset of the target tone. The deviation of the reported clock hand position from the actual position indexed perceptual latency. As expected, perceptual latency decreased with target tone intensity. Most importantly, however, greater temporal preparation decreased perceptual latency in all four experiments, especially for soft tones, which supports rather directly the idea that temporal preparation diminishes the duration of perceptual processing.