Automated 3-D tracking of video-captured movement using the example of an aquatic mollusk

We describe a computer program that tracks the three-dimensional coordinates of a snail (moving within a tank) from images captured by a single video camera. The tank and a mirror placed at 45° to one side are viewed to provide direct and reflected images of a pond snail,Lymnaea stagnalis, moving around the tank. The output of the camera is captured with an IBM-compatible PC using a frame-grabbing VideoBlaster board. The main features of our Windows program is the frame-by-frame analysis of the captured video, enhancement of contrast, location of dark “snails,” discrimination by size, trigonometric determination of thex, y, z coordinates, and the final export of data in a spreadsheet-ready format. After the user has outlined the position of the tank on the screen and set the discrimination thresholds, no further user activity is required. This makes the analysis of slowly moving mollusks much less operator intensive and less tedious. The method is applicable to other faster moving organisms (e.g., fish) because the analysis is performed on captured video sequences.     

Relationships between non-pathological dream-enactment and mirror behaviors

Dream-enacting behaviors (DEBs) are behavioral expressions of forceful dream images often occurring during sleep-to-wakefulness transitions. We propose that DEBs reflect brain activity underlying social cognition, in particular, motor-affective resonance generated by the mirror neuron system. We developed a Mirror Behavior Questionnaire (MBQ) to assess some dimensions of mirror behaviors and investigated relationships between MBQ scores and DEBs in a large of university undergraduate cohort. MBQ scores were normally distributed and described by a four-factor structure (Empathy/Emotional Contagion, BehavioralImitation, Sleepiness/Anger Contagion, Motor Skill Imitation). DEB scores correlated positively with MBQ total and factor scores even with social desirability, somnambulism and somniloquy controlled. Emotion-specific DEB items correlated with corresponding emotion-specific MBQ items, especially crying and smiling. Results provide preliminary evidence for cross-state relationships between propensities for dream-enacting and mirror behaviors—especially behaviors involving motor-affective resonance—and our suggestion that motor-affective resonance mediates dream-enactment imagery during sleep and emotional empathy during waking.     

A social cichlid fish failed to pass the mark test

Since the pioneering work in chimpanzees, mirror self-recognition (MSR), the ability to recognise oneself in a mirror, has been reported in great apes, Asian elephants, dolphins, and some social birds using the mark test, in which animals that possess MSR touch an imperceptible mark on their own bodies only when a mirror is present. However, giant pandas, which are solitary, failed to pass the mark test, suggesting that MSR evolved solely in highly social animals. In contrast to the increasing evidence of MSR in mammals and birds, little is known about MSR in fish. A Tanganyikan cichlid, Neolamprologus pulcher, is a good candidate for study because these fish live in highly social groups and recognise conspecifics about as rapidly as primates. We examined their responses to a mirror image and tested whether N. pulcher could pass the mark test. When the mirror was first exposed, they stayed in front of the mirror and exhibited aggressive behaviour towards the mirror image. These social behaviours suggested that the focal fish perceived the mirror image as an unfamiliar conspecific. The social responses decreased over the following days, as has generally been the case in animals with MSR. After mark injection, we found no increase in scraping behaviour or prolonged observation of the marked side. These results show a lack of contingency checking and mark-directed behaviours, meaning that N. pulcher failed to pass the mark test and did not recognise their self-image in the mirror.     

Visual self-recognition in mirrors and live videos: Evidence for a developmental asynchrony

Three experiments (N = 123) investigated the development of live-video self-recognition using the traditional mark test. In Experiment 1, 24-, 30- and 36-month-old children saw a live video image of equal size and orientation as a control group saw in a mirror. The video version of the test was more difficult than the mirror version with only the oldest children's performance approaching ceiling. In Experiment 2, most 24-month-olds showed self-recognition when presented with a TV-set that featured a mirror in place of a screen. This finding does not substantiate the possibility that expectations about what appears on TV are responsible for the asynchrony. In Experiment 3, children were given a mark-test involving only their legs. Again, a video version was more difficult than previously reported performance with mirrors, suggesting that the impossibility of eye-contact in video cannot explain this developmental asynchrony. The findings suggest that self-recognition can be added to the growing list of contexts in which 2-year-olds display what has been called a “video deficit” [Anderson, D. R., & Pempek, T. A. (2005). Television and very young children. American Behavioral Scientist, 48, 505–532].     

Nightmare frequency is related to a propensity for mirror behaviors

We previously reported that college students who indicated engaging in frequent dream-enacting behaviors also scored high on a new measure of mirror behaviors, which is the propensity to imitate another person’s emotions or actions. Since dream-enacting behaviors are frequently the culmination of nightmares, one explanation for the observed relationship is that individuals who frequently display mirror behaviors are also prone to nightmares. We used the Mirror Behavior Questionnaire (MBQ) and self-reported frequencies of nightmares to assess this possibility.A sample of 480 students, consisting of 188 males (19.2 ± 1.73 years) and 292 females (19.0 ± 1.55 years) enrolled in a first-year university psychology course, participated for course credit. They completed a battery of questionnaires that included the 16-item MBQ, plus an item about nightmare frequency (NMF) in the past 30 days. NMF scores were split to create low, medium, and high NMF groups.MBQ total scores were significantly higher for female than for male subjects, but an interaction revealed that this was true only for Hi-NMF subjects. MBQ Factor 4, Motor Skill Imitation, paralleled this global interaction for females, whereas MBQ Factor 3, Sleepiness/Anger Contagion, was elevated only for Hi-NMF males. Item analyses indicated that Hi- and Med-NMF females scored higher than Lo-NMF females on the 3 items of Factor 4 that reflect voluntary imitation (imitating famous/cartoon voices, being a physically active spectator, and learning new skills by observing), as well as on 2 other items that reflect involuntary imitation (contagious yawning and self-rated empathy). Although Hi- and Lo-NMF males differed most clearly on the sleepiness item of Factor 3, all 3 items on this factor (including anger contagion and contagious yawning) are plausibly associated with perception of and response to social threat.Results provide evidence that among females nightmares are associated with voluntary and involuntary mirror behaviors during wakefulness, while among males nightmares are associated with threat-related mirror behaviors during wakefulness. They thus support the possibility that the association between mirror behaviors and dream-enacting behaviors is due to a common mirror neuron mechanism that underlies mirror behaviors and nightmares and that involves motor, rather than emotional, resonance. These results have implications for understanding the comorbidity of nightmares and other pathological symptoms such as imitative suicidal behaviors, the influence of observational learning on dissociative symptomatology, and the predominance of threat and aggression in the dream enacting behaviors of REM sleep behavior disorder.     

A simple stereo television system with application to the measurement of three-dimensional coordinates of fish in schools

Stereo television is achieved through a rapid switch circuit that alternately selects fields from a pair of matched television cameras. Images are recorded with conventional VCRs. After image positions are digitized, stereo coordinates are estimated relative to a calibration grid, which may be removed during an experiment. Necessary geometry, including calibration and iteration procedures, is detailed. The method is flexible and accurate enough to allow the use of zoom, pan, and tilt on both cameras when a calibration grid is retained in view. Examples of the system’s application are given for the measurement of three-dimensional coordinates of fish in schools, both for glass-fronted aquarium tanks and in the natural environment using underwater television in sea cages.     

Response acquisition by Siamese fighting fish (Betta splendens) with delayed visual reinforcement

Male Siamese fighting fish, Betta splendens, swam through a ring in an aquarium, breaking a photocell beam and initiating an unsignaled, resetting delay interval. Following delays of 0 s, 10 s, or 25 s, a 15-s mirror presentation released an aggressive display by the fish. Swimming through the ring increased in the absence of either a period of acclimatization to the reinforcer (analogous to magazine training when appetitive reinforcers are used) or explicit training of the response by the experimenters. Response rates were a decreasing function of delay duration. Other fish exposed to a schedule of response-independent mirror presentations failed to acquire and maintain the response. The results demonstrate the robustness and generality of the phenomenon of response acquisition with delayed reinforcement. They further qualify earlier observations about behavioral mechanisms involved in the phenomenon.     

A device that provides an eye-to-eye video perspective for interactive television

A device that allows individuals to engage in eye contact while interacting over two-way television is described. The apparatus consists of a television monitor and low light-level television camera housed within a cabinet containing a mirror system that resembles a combination beam splitter and periscope. Through the mirror system, the pick-up camera captures a reflected full-face eye-level image of the television viewer as he or she attends to the display monitor. The device is particularly useful for studying the nonverbal communication patterns of individuals engaged in social interaction.     

Mirror systems and simulation: a neo-empiricist interpretation

It is often claimed that the discovery of mirror neurons supports simulation theory (ST). There has been much controversy about this, however, as there are various competing models of the functional contribution of mirror systems, only some of which characterize mirroring as simulation in the sense required by ST. But a brief review of these models reveals that they all include simulation in some sense. In this paper, I propose that the broader conception of simulation articulated by neo-empiricist theories of concepts can subsume the more specific conceptions of simulation presented by ST and by these other models, thereby offering a framework in which each of these models may play a role. According to neo-empiricism, conceptual thought in general involves simulation in the sense that it is grounded in sensory, motor, and other embodied systems (Barsalou, Behavioral and Brain Sciences, 22, 577?C609, 1999, Philosophical Transactions of the Royal Society of London: Biological Sciences, 364, 1281?C1289, 2009; Barsalou et al., Trends in Cognitive Sciences, 7(2), 84?C91, 2003; Prinz 2002, Mind & Language, 25(5), 612?C621, 2010; Glenberg and Robertson, Journal of Memory and Language, 43, 379?C401, 2000). Crucially, the term ??simulation?? here refers not to simulations of a target agent??s experience in the sense endorsed by simulation theory but to the activation of sensory, motor, affective, and introspective representations. This difference does not entail that neo-empiricism must be in competition with ST??indeed, I will propose that ST can be embedded as a special case within neo-empiricism.     

Automated gait analysis in the open-field test for laboratory mice

In this article, an automated and accurate mouse observation method, based on a conventional test for motor function evaluation, is outlined. The proposed measurement technique was integrated in a regular open-field test, where the trajectory and locomotion of a free-moving mouse were measured simultaneously. The system setup consisted of a transparent cage and a camera placed below it with its lens pointing upward, allowing for images to be captured from underneath the cage while the mouse was walking on the transparent cage floor. Thus, additional information was obtained about the position of the limbs of the mice for gait reconstruction. In a first step, the camera was calibrated as soon as it was fixed in place. A linear calibration factor, relating distances in image coordinates to real-world dimensions, was determined. In a second step, the mouse was located and its body contour segmented from the image by subtracting a previously taken “background” image of the empty cage from the camera image. In a third step, the movement of the mouse was analyzed and its speed estimated from its location in the past few images. If the speed was above a 1-sec threshold, the mouse was recognized to be running, and the image was further processed for footprint recognition. In a fourth step, color filtering was applied within the recovered mouse region to measure the position of the mouse’s paws, which were visible in the image as small pink spots. Paws that were detected at the same location in a number of subsequent images were kept as footprints—that is, paws in contact with the cage floor. The footprints were classified by their position relative to the mouse’s outline as corresponding to the front left or right paw or the hind left or right paw. Finally, eight parameters were calculated from the footprint pattern to describe the locomotion of the mouse: right/left overlap, front/hind base, right/left front limb stride, and right/left hind limb stride. As an application, the system was tested using normal mice and mice displaying pentobarbital-induced ataxia. The footprint parameters measured using the proposed system showed differences of 10% to 20% between normal and ataxic mice.     

Submerged electrodes in an aquarium: Validation of a technique for remote sensing of behavior

Necturus maculosus has been selected as representative of a class of neotenic amphibia whose behavior (including gill beat, heartbeat, and tail waving) can be sensed remotely by submerged electrodes in an aquarium. This communication presents a validation of the technique as a preface to reports on the electrophysiology of behavior in unrestrained surgically naive salamanders. Although the sources of the submarine signals are not known with certainty, they apparently depend on two factors: (1) aquarium water of appropriate ionic strength serves as a volume conductor for activity, and (2) animal movement displaces water or produces waves which are sensed as a change in potential at the water-electrode interface. This method provides a continuous comprehensive record of behavior simultaneously from several response systems in a freely behaving animal.     

Private self-consciousness and perceptions of self-consistency

The relationships of self-consciousness and mirror induced self-awareness to judgements of self-consistency were investigated. Ss were selected on the basis of private and public self-consciousness scores (Feningstein, Scheier and Buss, 1975; J. consult. clin. Psychol. 43 522–527). They then completed the Gergen-Morse Self-Consistency measure (Gergen and Morse, 1967; Proc. Am. Psychol. Ass. 75, 207–208) under either low or high self-awareness conditions. High self-awareness condition Ss completed the measure while sitting in front of a mirror; no mirror was present for low self-awareness condition Ss. The results indicated that high private self-consciousness was related to perceptions of enhanced self-consistency. No effects related to level of public self-consciousness or to mirror induced self-awareness emerged. The implications of chronic self-reflection for the nature of one's self-concept are discussed.     

On the choice between eating and aggressive display in the Siamese fighting fish (Betta splendens)

In Expt 1, male Betta splendens were given a choice between food and a mirror image in a T-maze. All fish consistently preferred food. In Expt 2, the choice of fish that lived in the T-maze for the duration of the experiment was compared with the choice of fish that were transferred to the T-maze for each experimental session. Fish that lived in the T-maze consistently preferred food, but fish that were transferred showed a shift in preference toward mirror image. Differential inhibition of hunger and aggression by fear is suggested as the cause of the preference shift.     

The Alienating Mirror: Toward a Hegelian Critique of Lacan on Ego-Formation

This article brings out certain philosophical difficulties in Lacan’s account of the mirror stage, the initial moment of the subject’s development. For Lacan, the “original organization of the forms of the ego” is “precipitated” in an infant’s self-recognition in a mirror image; this event is explicitly prior to any social interactions. A Hegelian objection to the Lacanian account argues that social interaction and recognition of others by infants are necessary prerequisites for infants’ capacity to recognize themselves in a mirror image. Thus mutual recognition with another, rather than self-recognition in a mirror, is what makes possible subsequent ego-formation and self-consciousness. This intersubjective critique suggests that many of the psychoanalytic consequences that Lacan derives from the mirror stage (e.g., alienation, narcissism, and aggressivity) may need to be rethought.

Individual pitch functions and pitch-duration cross-dimensional matching

Eight young adult subjects scaled the auditory dimensions of duration and pitch using a modified method of numerical magnitude balance and adjustment of the stimuli for individual equal-loudness differences. Individual duration and pitch functions for magnitude estimation and for magnitude production fit the power law well. When compared with the revised reel scale and the pitch function obtained by S. S. Stevens and Galanter (Journal of Experimental psychology, 1957,54, 377–411), the group magnitude estimation and magnitude production pitch functions plotted in log-log coordinates showed high degrees of linearity. This was due mostly to the absence of a rollover in the high-frequency range of the continuum. It was hypothesized that pitch may be viewed as a linear function. This hypothesis was further supported when the exponents of the pitch and duration functions were used to predict closely the group exponent of cross-dimension matches.     

A system for automatic recording and analysis of motor activity in rats

We describe the design and evaluation of an electronic system for the automatic recording of motor activity in rats. The device continually locates the position of a rat inside a transparent acrylic cube (50 cm/side) with infrared sensors arranged on its walls so as to correspond to the x-, y-, and z-axes. The system is governed by two microcontrollers. The raw data are saved in a text file within a secure digital memory card, and offline analyses are performed with a library of programs that automatically compute several parameters based on the sequence of coordinates and the time of occurrence of each movement. Four analyses can be made at specified time intervals: traveled distance (cm), movement speed (cm/s), time spent in vertical exploration (s), and thigmotaxis (%). In addition, three analyses are made for the total duration of the experiment: time spent at each x–y coordinate pair (min), time spent on vertical exploration at each x–y coordinate pair (s), and frequency distribution of vertical exploration episodes of distinct durations. User profiles of frequently analyzed parameters may be created and saved for future experimental analyses, thus obtaining a full set of analyses for a group of rats in a short time. The performance of the developed system was assessed by recording the spontaneous motor activity of six rats, while their behaviors were simultaneously videotaped for manual analysis by two trained observers. A high and significant correlation was found between the values measured by the electronic system and by the observers.     

An affordable computer-aided method for conducting Morris water maze testing

A relatively inexpensive and reliable computer-aided method for assessing Morris water maze performance is described. The procedure uses SigmaScan digitizing software (Jandel Scientific, San Rafael, CA) to collect distance swum data, while escape latencies are measured with a hand-held stopwatch. Swim paths are videotaped for subsequent viewing and saved on disk as data sets ofx,y coordinates. At a later time,x,y data files are printed and analyzed to obtain additional performance measures (e.g., distance swum in previous reinforced quadrant, heading angle, etc.). Intra- and interrater reliabilities associated with this method are presented. Correlation coefficients in ther = .85?.90 and above range are reported for both reliability types. Given its approximate cost of $1,500 (excluding the price of an IBM-compatible computer), the present procedure potentially can aid in performing instructional and research activities at small colleges which typically lack extensive equipment budgets.     

A probabilistic multidimensional scaling with unique axes1

Abstract: A probabilistic multidimensional scaling model is proposed. The model assumes that the coordinates of each stimulus are normally distributed with variance Σ_i = diag(σ²₁, … σ²_Ri). The advantage of this model is that axes are determined uniquely. The distribution of the distance between two stimuli is obtained by polar coordinates transformation. The method of maximum likelihood estimation for means and variances using the EM algorithm is discussed. Further, simulated annealing is suggested as a means of obtaining initial values in order to avoid local maxima. A simulation study shows that the estimates are accurate, and a numerical example concerning the location of Japanese cities shows that natural axes can be obtained without introducing individual parameters.     

The use of an ultrasonic monitor for recording locomotor activity

An ultrasonic activity monitor has been designed that can be used to detect motion in air or within an aquarium. Stability and linearity of response of the monitor have been measured. The system has been used to examine activity rhythms of the marine invertebrate,Octoput ornatus Gould.     

Scaling space with the mirror illusion: The influence of body plasticity on perceived affordances

How do body representations influence decisions about action? We developed a novel paradigm using the mirror illusion (Holmes, Crozier, & Spence, in Cognitive, Affective, & Behavioral Neuroscience, 4, 193–200, 2004) to examine two ways of evoking body plasticity—extension of body capabilities and visual capture—and its influence on perceived affordances. In two experiments, we manipulated the action capabilities of a seen left hand by lengthening the arm with a rod (Exp. 1) or enlarging the hand with a glove (Exp. 2). The right hand was unaltered physically and was occluded by placement in a mirror box. We induced visual capture through synchronous finger movements of both hands. Right-hand estimates of reaching and of fitting through apertures increased relative to actual capabilities during visual capture, supporting the claim that visual capture can induce the incorporation of an apparent body extension into action decisions. The results suggest that both perceptual and cognitive influences on bodily awareness underlie perceived affordances.