A SIMPLE 2‐TRANSISTOR TOUCH OR LICK DETECTOR CIRCUIT

An easily constructed and inexpensive battery operated circuit is described for use as a lickometer or contact detector in behavioral studies with rodents.     

RESPONSE ACQUISITION BY HUMANS WITH DELAYED REINFORCEMENT

The present experiment examined whether a response class was acquired by humans with delayed reinforcement. Eight white circles were presented on a computer touch screen. If the undergraduates touched two of the eight circles in a specified sequence (i.e., touching first the upper‐left circle then the bottom‐left circle), then the touches initiated an unsignaled resetting delay culminating in point delivery. Participants experienced one of three different delays (0 s, 10 s, or 30 s). Rates of the target two‐response sequence were higher with delayed reinforcement than with no reinforcement. Terminal rates of the target sequence decreased and postreinforcement pauses increased as a function of delay duration. Other undergraduates exposed to yoked schedules of response‐independent point deliveries failed to acquire the sequence. The results demonstrate that a response class was acquired with delayed reinforcement, extending the generality of this phenomenon found with nonhuman animals to humans.     

A computer touch-screen apparatus for training visual discriminations in rats.

We describe an operant conditioning apparatus that uses computerized touch-screen technology and is designed for the versatile and highly controlled testing of rats in a potentially wide variety of behavioral paradigms. Although computer-controlled touch-screen systems have been developed for use with pigeons, monkeys, and humans, analogous technologies and methods have not yet been developed for rats. The development of a touch-screen system for rats could enhance the efficiency of behavioral research with rats, and may offer a unique tool for studying animal learning. In the first test of the utility of the apparatus, 3 Sprague-Dawley rats learned to activate the touch screen only after the touch-screen panel was made slightly movable. These animals then learned to discriminate visual stimuli presented on the computer monitor, but only after the food magazine and pellet dispenser were moved to the rear of the chamber opposite the stimulus display and response window. In a test of the utility of the modified apparatus, 6 Long-Evans rats learned to activate the touch screen and learned one of three different simple discriminations using computer-generated, visually presented stimuli. A basic method for training rats to activate the computer touch screen and for visual discrimination training is described. Results show that rats learned to activate the touch screen and discriminate visual stimuli presented on a computer monitor. Potential applications and advantages of the touch-screen-equipped rat operant conditioning chamber are discussed.     

Intertrial sources of stimulus control and delayed matching-to-sample performance in humans

Two experiments compared delayed matching-to-sample (DMTS) accuracy under 2 procedures in adults with mental retardation. In the trial-unique procedure, every trial in a session contained different stimuli. Thus, comparison stimuli that were correct on one trial were never incorrect on other trials in that session (or vice versa). In the 2-sample DMTS procedure, the same 2 comparison stimuli were presented on each trial, and their function changed quasi-randomly across trials conditional upon the sample stimulus. Across 2 experiments, 7 of 8 subjects showed the highest overall accuracy under the trial-unique procedure, and no subject showed consistently higher accuracy under the 2-sample procedure. Negative, exponential decay functions fit to logit p values showed that this difference was due largely to the steeper delay-mediated decline in sample control for the 2-sample procedure. Stimulus-control analyses indicated that, under the 2-sample procedure, the selection of the comparison stimulus on Trial N was often controlled by the comparison stimulus selection on Trial N-1 rather than the Trial-N sample stimulus. This source of competing stimulus control is not present in trial-unique procedures. Experiment 2 manipulated intertrial interval duration. There was a small but consistent increase in accuracy as a function of intertrial interval duration under the 2-sample procedure, but not under the trial-unique procedure.     

Oxford cognitive screen: A critical review and independent psychometric evaluation

The Oxford cognitive screen (OCS) is a stroke-specific cognitive screening assessment. Although the test developers have provided psychometric information for the assessment, the OCS has received minimal external scrutiny, with which to triangulate the underpinning psychometrics. The purpose of this study is to provide a critical review and independent validation of the OCS. This study analysed data from an anonymised clinical database, which consisted of 316 patients who were assessed using the OCS on an Acute Stroke Unit. The rates of impairment on tests of memory and receptive communication were lower than expectation, suggesting that these subtests may be relatively insensitive. Patients with aphasia were more likely to be unable to categorised as impaired on non-language tests, suggesting that they remain sensitive to language processing or non-dominant hand usage. Some of the subtests of the OCS achieve high retest reliability, which makes them good candidates for measuring cognitive change over time. Although the OCS has many advantages, it is also important to adequately consider its limitations, that is insensitivity to memory problems, the potential confounding impact of non-dominant hand usage, and the potential that some tests may sample overall cognitive ability instead of domain-specific functioning.     

Exploring maternal touch in the infant’s first 18 months of Life: A study on an Italian sample

Affective touch is a crucial component of caregiving in early life and constitutes a key factor with a significant impact on infant later-life outcomes. The Parent-Infant Caregiving Touch Scale (PICTS) allows to quantify and qualify the caregiver's self-perception of touch in the first months of an infant’s life. In the current study, we contributed to validation of the PICTS in the Italian language in order to explore whether early maternal touch would be associated with maternal emotional state, maternal history of affective touch experiences throughout the lifespan, and infants’ sex and age. Data analyses were run on a sample of 377 Italian mothers (mean age = 33.29; SD = 4.79) participating in an online survey. Confirmatory factor analysis was applied. A three-dimensional structure of PICTS (i.e., stroking, affective communication, and holding) after removing one item out resulted in the best model in our sample. Maternal emotional state did not affect PICTS factor scores while maternal comfort and amount of affective touch experienced during adulthood was significantly associated with the stroking, affective communication, and holding factors. Regarding infants’ dimensions, infants’ sex and age were not associated with PICTS factor scores. Findings suggest that the PICTS Italian version is a good measurement of caregiver's self-perception of touch in early infancy and that maternal history of touch is associated with a mother’s current use of touch.     

Blind children recognizing tactile pictures respond like sighted children given guidance in exploration

Theory of tactile pictures argues that untrained blind subjects can recognize raised, outline pictures. It contends the blind person’s knowledge of the shapes of common objects is like that of the sighted, and the blind person’s pictorial abilities use the same principles as the sighted person’s. To test this theory, blind children (aged 8–13) and blindfolded age-matched sighted children were asked to identify raised-line drawings of common objects. Their performances were correlated. In addition, the blind children identified more than sighted children exploring the pictures actively, but the same number of pictures as sighted children who were given passive, guided exploration. We argue blind and sighted children use the same principles to identify the pictures, but the blind have superior exploration skills. The differences in the effects of exploration skills on recognition scores are minimized when the sighted children are given guidance, since the sighted children then have efficient contact with the displays, and the performance of the sighted and the blind is then governed by the same principles, without one group benefitting from advantages in exploration skills.     

Depressive Symptomatology and College Persistence among African American College Students

ABSTRACT. While many studies find women self-report higher disgust sensitivity than men, few studies have examined gender differences with behavioral tasks in senses other than vision. On a haptic task, we tested the hypothesis that women would report greater disgust but not greater unpleasantness than men. Forty-four undergraduates (29 women) touched 8 out-of-sight stimuli with sensory (unpleasantness) and emotional (disgust) responses recorded. The stimuli consisted of 2 neutral, 2 pleasant, and 4 unpleasant (3 disgust-evoking) objects. No gender differences were found for reporting stimuli unpleasantness. In contrast, women rated their disgust significantly higher than men when touching the high disgust-evoking objects. Unpleasantness of the stimuli correlated with disgust to the objects, but disgust sensitivity (Disgust Scale-Revised) was not a strong predictor of disgust responses. Besides differentiating unpleasantness from disgust, this was also the first study to show gender differences in a disgust-evoking haptic task.     

The screen memory and the act of remembering

Screen memories, seen by Freud, Greenacre and other analysts of a past generation as a key source of data for the reconstruction of psychic and historical reality, have been relatively neglected in contemporary analysis. A fresh look shows that these durable, constant memories have a dual relation to childhood experience: they memorialize both a specific organization of trauma, wish and defense, and a private childhood act of remembering. Close attention to the screen memory itself and the context in which it appears indicates that both aspects of screen memory have meaning for the individual and are represented in fantasy. Both currents of meaning can be seen in a literary screen memory and in the clinical situation, where both play out in transference and countertransference.     

Aging-related cocontraction effects during ankle strategy balance recovery following tether release in women

Increased antagonistic muscle activation during balance recovery has been documented during proprioceptive reliant responses in older adults. The authors examined ankle muscle cocontraction levels in young and older adults during balance recovery from a tether-release-induced, vestibular-input-reliant perturbation. Nine healthy young adult and 9 older women without history of falls performed maximum isometric plantar flexion and dorsiflexion trials followed by balance recovery trials using the ankle strategy. Surface electromyography data normalized to isometric conditions were analyzed during the 100 ms prior to release, the 50 ms immediately after release, and the 100-ms epochs from 100-400 ms following release. No differences existed in gastrocnemius and soleus activity levels (p > .05), though antagonistic tibialis anterior activity was greater in the older adults during the 300-400 ms epoch (young: 23.5 ± 5.8%, older: 38.7 ± 9.4%; p = .001). Vestibular-dominated perturbations may increase antagonistic activity during the recovery phase in older adults, inhibiting efficient balance recovery during proprioceptive and vestibular reliant perturbations.