The effects of distributed training on retention of operant conditioning in human infants

Long-term retention of operant footkicking acquired in the mobile conjugate reinforcement paradigm was assessed as a function of the distribution of training time. In the first study, 3-month-old infants were trained for either one 18-min session or for two 9-min or three 6-min sessions separated by 24-hr intervals. All infants exhibited retention during a test administered immediately after training, but only those trained in a single session continued to perform the conditioned response during cued-recall tests 7 or 14 days later. Infants trained in three sessions showed no evidence of remembering the contingency even after a week. A warm-up decrement, seen in the day-to-day performance of infants in the distributed conditions, was eliminated in the second study by the interpolation of a nonreinforcement period at the outset of daily sessions. This procedure also enhanced long-term retention such that infants trained in three 6-min session now remembered the contingency for 14 days and did not differ from infants who had received a single 18-min session. Whether distributed training facilitates or impairs long-term retention appears to depend on the opportunity for infants to acquire a sufficient number (or kind) of effective retrieval cues during original learning.     

Operant conditioning in Lymnaea: evidence for intermediate- and long-term memory

Aerial respiration of the pond snail, Lymnaea stagnalis, can be operantly conditioned; however, the parameters necessary to produce long-term (LTM) or intermediate term memory (ITM) have not previously been investigated. We conducted training using procedures that varied in the duration of the training session, the number of training sessions per day or the amount of time between subsequent training sessions (SI). We found that by varying the duration and frequency of the training session learning could be differentially produced. Furthermore, the ability to form LTM was dependent not only on the duration of the training session was also the interval between training sessions, the SI. Thus it was possible to produce ITM, which persists for up to 3 hr, and not form LTM, which persists at least 18 hr. Learning, ITM, and LTM can be differentially produced by altering the SI, the duration of the training session, or the number of training sessions per day. These findings may allow us to begin to elucidate the underlying neural mechanisms of learning, ITM, and LTM.     

ON THE INABILITY OF INTERVAL TIME SAMPLING TO REFLECT FREQUENCY OF OCCURRENCE DATA1

Interval time sampling yields the result, percentage of intervals scored. It is rudimentary to note that this measure per se does not constitute a response dimension. It is a useful behavioral measure, therefore, only to the extent that it accurately reflects the nature and degree of the fundamental dimensions from which it is drawn i.e., frequency and duration. The correspondence between scored intervals and response duration is fairly well understood (Journal of Applied Behavior Analysis, 1975, 8 , 463–469; 1977, 10 , 325–332). This study determined the correspondence between scored intervals and response frequency. Eleven, 30-minute experimental sessions that differed along the variables of frequency of occurrence and time per response (the average length of a response per session) were computer simulated. In the first group of four sessions, the frequencies were 45, 100, 150, and 300; in these sessions, all responses ranged from one to three seconds. In the second group of four sessions, the frequencies were 31, 61, 101, and 152; in these sessions, all responses ranged from three to nine seconds. In the last group of three sessions, the frequencies were 25, 34, and 50; here, all responses ranged from nine to 27 seconds. The response distribution within the above ranges was rectangular, with each whole second represented once. The responses were selected by a random number generator, and on each trial every number in the distribution had an equal probability of occurrence. These provisions produced a linear pattern of responding. The time per response in the three groups of sessions were 2, 6, and 18 seconds. For all sessions, event recordings were made and analyzed. The analysis consisted of using partial interval time sampling to determine the percentage of intervals scored; this total was subdivided into intervals containing (1) single responses, (2) multiple responses, (3) continuing responses, and (4) response initiations or terminations. The analysis was performed when the length of the observation interval was 5, 10, 20, 30, 60, and 120 seconds. An additional session drawn from a study that contained real-life data was subjected to this same analysis. The most significant results were derived by finding the ratio of scored intervals containing single responses to the total intervals scored. If every scored interval contained a single response, this ratio would equal 1.0; if no scored interval contained a single response, the ratio would be 0.0. It can be seen that this ratio is an objective expression of the validity of interval time sampling as a measure of response frequency. Of 66 data points (11 sessions × six observation lengths per session), only five were equal to or greater than 0.80. These five points were all found in just two sessions (f = 45, 100). A validity index of less than 0.50 was observed in 49 of the 66 points. Also, the validity index increased, peaked, and then decreased within sessions as the length of the observation interval was increased. The results from the real-life session were in close agreement with those obtained from the simulations. The importance of these and previous findings lies in the demonstration that changes in scored intervals need not represent true behavior change. The data indicate that there are many combinations of behavioral frequency and duration where interval time sampling cannot produce valid measurement results.     

Schedule-induced polydipsia suppresses pituitary-adrenal activity in rats

The effects of schedule-induced polydipsia (SIP) on pituitary-adrenal activity, as indicated by plasma levels of corticosterone, were examined in a series of experiments. Male (Experiments 1 and 3) and female (Experiment 2) rats were reduced to 80% of their free-feeding weight and given daily sessions on an intermittent-feeding schedule (fixed time of 60 sec). Half of the subjects in each experiment had water available during experimental sessions and the other half did not. Animals with water available in the experimental chamber exhibited SIP in all three experiments. In Experiment 1, blood samples were collected following (a) food consumption in the home cage, (b) a session on FT 60 sec, and (c) a session with pellets available in a cup in the experimental chamber. In Experiment 2, blood samples were taken prior to and following an FT 60-sec session, and following a session with pellets available in a cup in the chamber. In Experiment 3, pre- and postsession samples were obtained as in Experiment 2 (Part A). Subsequently, the opportunity to drink during sessions was removed, and the effect on corticoids was examined (Part B). The results indicate that (a) schedule-induced drinking suppresses pituitary-adrenal activity, (b) corticoid suppression may become a conditioned response to drinking in the chamber, and (c) corticoids return to presession levels following removal of water from the chamber. In view of these findings, it is hypothesized that SIP may serve an arousal-reducing role in intermittent-feeding situations.     

Subthreshold white noise vibration alters trembling sway in older adults

BackgroundSomatosensory deficit is a significant contributor to falls in older adults. Stochastic resonance has shown promise in recent studies of somatosensation-based balance disorders, improving many measures of stability both inside and outside of the clinic. However, our understanding of this effect from a physiological perspective is poorly understood. Therefore, the primary goal of this study is to explore the influence of subthreshold vibratory stimulation on sway under the rambling-trembling framework.Methods10 Healthy older adults (60–65 years) volunteered to participate in this study. Each participant underwent two randomized testing sessions on separate days, one experimental and one placebo. During each session, the participants' baseline sway was captured during one 90-s quiet standing trial. Their sensation threshold was then captured using a custom vibratory mat and 4–2-1 vibration perception threshold test. Finally, participants completed another 90-s quiet standing trial while the vibratory mat vibrated at 90% of their measured threshold (if experimental) or with the mat off (if placebo). While they completed these trials, an AMTI force plate collected force and moment data in the anteroposterior (AP) and mediolateral (ML), from which the center of pressure (COP), rambling (RM), and trembling (TR) time series were calculated. From each of these time series, range, variability (root-mean-square), and predictability (sample entropy) were extracted. One-tailed paired t-tests were used to compare baseline and during-vibration measures.ResultsNo significant differences were found during the placebo session. For the experimental session, significant increases were found in AP TR range, ML TR RMS, AP COP predictability, and AP & ML TR predictability. The TR time series was particularly sensitive to vibration, suggesting a strong influence on peripheral/spinal mechanisms of postural control.SignificanceThough it is unclear whether observed effects are indicative of “improvements” or not, it does suggest that there was a measurable effect of subthreshold vibration on sway. This knowledge should be utilized in future studies of stochastic resonance, potentially acting as a mode of customization, tailoring vibration location, duration, magnitude, and frequency content to achieve the desired effect. One day, this work may aid in our ability to treat somatosensation-based balance deficits, ultimately reducing the incidence and severity of falls in older adults.     

How does the manipulation of time pressure during soccer tasks influence physical load and mental fatigue?

This study aimed to analyze whether having more or less time to solve soccer tasks influences physical load and mental fatigue. 48 semi-professional soccer players, from teams in national leagues participated (M_age = 22.4, SD_age = 2.25). They carried out 2 sessions with 4 tasks in each session. In one session, there was more time available; in the other, there was less time available. GPS technology was used to measure physical load, and an adaptation of NASA and Visual Analog Scale to measure mental load and mental fatigue. A related-samples T-test and magnitude based on inference were used to determine the possible effect. Soccer players reported that tasks with less available time were more mentally demanding. Moreover, less available time to solve the tasks significantly increased players’ RPE and decreased their Heart Rate and external physical load. Therefore, the available time significantly affects mental and physical load and mental fatigue.     

The distributed learning effect for children's acquisition of an abstract syntactic construction

In many cognitive domains, learning is more effective when exemplars are distributed over a number of sessions than when they are all presented within one session. The present study investigated this distributed learning effect with respect to English-speaking children's acquisition of a complex grammatical construction. Forty-eight children aged 3;6–5;10 (Experiment 1) and 72 children aged 4;0–5;0 (Experiment 2) were given 10 exposures to the construction all in one session (massed), or on a schedule of two trials per day for 5 days (distributed-pairs), or one trial per day for 10 days (distributed). Children in both the distributed-pairs and distributed conditions learnt the construction better than children in the massed condition, as evidenced by productive use of this construction with a verb that had not been presented during training. Methodological and theoretical implications of this finding are discussed, with particular reference to single-process accounts of language acquisition.     

Discriminative performance of the domestic hen in a visual acuity task

The performance of 6 domestic hens on a visual acuity task was studied using a spatial discrete-trial conditional discrimination procedure. Gray stimuli and vertical square-wave gratings, ranging in spatial frequency from 1 to 10 cycles per millimeter, were presented in a descending and ascending series of probes. On each trial, either a grating or gray stimulus was presented. Only one spatial frequency of grating was presented during each session. Between probe sessions, training continued at the coarsest grating value. Stimulus discriminability, measured as values of log d, changed with changes in grating spatial frequency for both probe series. Fitted lines described the linear portion of the psychometric functions. Thresholds estimated from the lines generally ranged from four to six cycles per degree, with slightly greater estimates from data from the descending probe series. There were no systematic changes in response bias as a function of grating spatial frequency.     

The effect of punishment and reinforcement procedures on a stutterer's factor II avoidance response

The purpose of this clinical experiment was to investigate the manipulability of a Factor II avoidance response (arm movement). The substantive hypothesis under test was that its suppression would be enhanced by repeated punishment sessions. During the first of nine therapy sessions response-contingent negative stimulation was not delivered. In the next five, after a base-rate period, “wrong” was made consequent upon the target response. In each of these sessions the suppression of arm movement was apparent. However, the magnitude of the suppression decreased from session to session. Evidently, the continued use of punishment did not enhance suppression. Because of this finding procedural changes were introduced in the next three therapy sessions. Verbal praise was added as a consequence of increasingly stringent omission criteria and three consecutive units of praise led to time-out from the reportedly fatiguing task of continuous speech. A marked reduction and then complete extinction resulted. Moreover, learning was evidenced since the frequency of arm movement lessened in the base-rate period of each session.     

Using an Advance Time Meter display as means to reduce driving speed

ObjectiveTesting an experimental means to reduce motivation to drive fast.BackgroundOne determinant of that motivation may be a wrong presumption, demonstrated here: Time to reach destination declines about linearly to increase in driving speed. Actually, that time is a linear function of advance time, the inverse of speed. It is hypothesized that the behavioral by-product of the popularity of that fallacy could be counteracted by introducing an essential change to the speed-based continuous feedback provided to the driver – from a speedometer displaying instantaneous velocity to a gauge reporting advance time (denoted ATM), so that both average driving speed and speed variance are reduced.MethodIn two driving simulator experiments, driving speed of participants presented with either of the two types of gauge was recorded.ResultsThe main finding is that driving with feedback provided by an ATM gauge following prior briefing led to a significant reduction – ∼11 km/h – in mean speed, as well as to a significant reduction in between-driver speed variability, as compared with driving with an ordinary speedometer. It was also found that no significant difference was observed in the speeding behavior of participants driving with an ATM display for three ∼2-h sessions administered in three different days, so that the last session took place within seven days from the first one.ConclusionThe ATM gauge serves to reduce motivation to speed.ApplicationWidespread use of the ATM gauge may result in reduction in number and intensity of accidents.     

The Effects of Response Repetitions on Sight Word Acquisition for Students with Mild Disabilities

Single response learning trials, defined in terms of the three-term contingency model, were compared with repeated response learning trials. The purpose of Study 1 was to assess the effectiveness and efficiency of single and repeated response learning trials on sight word remediation. In Study 1, one single response learning trial having one response opportunity per word was compared to one repeated response learning trial having five response opportunities. In Study 2, three single response trials were compared to three repeated response trials. In both studies, the training conditions were compared using an alternating treatments design. Measuring the cumulative number of sight words mastered showed the training conditions equally effective. However, measuring (a) the mean duration of training sessions, (b) the cumulative frequency of words mastered per session duration, (c) the mean number of training sessions per word required for mastery, and (d) the training time per mastered word showed that the single response condition was more efficient. Discussion focuses on the need to include training data when determining best practices for teaching.     

Lingual vibrotactile threshold alterations in response to varying stimulation levels of intensity and duration.

Lingual vibrotactile thresholds were obtained at a frequency of 250 Hz by using an ascending-continuous series of stimulation during five sessions. Each of three adult male Ss attended a control session which included a prescribed period of constant tongue positioning, a pre-experimental session where the mean of six thresholds was obtained as a basis of further testing, and three experimental sessions. In the experimental sessions vibrotactile thresholds after exposure to vibratory stimulation of varying levels of intensity and duration were obtained. The findings of the control session reflected a slight pattern of decreased lingual sensitivity indicative of the influential factor of constant maintenance of tongue positioning. Results from the experimental sessions demonstrated shifts toward progressively decreased lingual sensitivity after exposure to vibratory signals of increased levels of intensity and duration. A recovery phase to near-normal sensitivity followed each stimulus presentation.     

THE USE OF IMPOSED AND SELF-SELECTED TRAINING PACKAGES TO ESTABLISH CLASSROOM TEACHING SKILLS1

Although much is known about techniques for teaching elementary pupils in the classroom, no procedures have been consistently effective in training teachers to use these techniques. In the present study, six teacher trainees were observed individually and trained sequentially to use a variety of teaching skills: praise for academic responses, praise for appropriate classroom behavior, correction procedures for incorrect academic responses, and token fines. These skills were examined under four conditions: (1) baseline sessions were taught by the trainees before any instructions on the use of the teaching skills. (2) Instruction sessions were taught by the trainees after they were given instructions describing the use of several teaching skills. (3) During each Imposed-Package session, the trainees received modelling, verbal feedback, graphic feedback, and grade and quiz contingencies on their use of a particular teaching skill. (4) During each Self-Selected Package session, a grade contingency was in effect with the trainees choosing the components (modelling, verbal feedback, graphic feedback, quiz contingency) they wanted included in their training package for a particular skill. The effects of instructions were quite varied. Large increases on three of the four skills occurred with one trainee; almost no changes occurred with another trainee; and changes with the remaining four trainees fell within these extremes. The Imposed and Self-Selected Packages reliably increased the use of teaching skills, including those skills for which instructions had not been effective. The Self-Selected Package was considered to be as effective as the Imposed Package, since the time required for training a teaching skill varied from two to nine sessions with both packages. Under the Self-Selected Package, the trainees chose from modelling, verbal feedback, and graphic feedback, but none chose the quiz contingency. Questionnaire data collected after training showed that all six trainees preferred the Self-Selected Package to the Imposed Package. The effectiveness of the Self-Selected Package, together with the trainees' preference for it, suggests that it may be desirable for teacher training programs to specify the teaching skills, arrange a contingency for performance, and allow trainees to choose which additional components are to be used in each training session.     

The impact of infant-directed videos on parent-child interaction

This study assessed whether infant-directed videos designed to promote parent-child interactions actually support such engagement. Parents watched videos from the Baby Einstein or the Sesame Beginnings series for 2 weeks at home with their 12- or 18-month-old infants. Baby Einstein encourages parents to label objects and actions; Sesame Beginnings models activities in which parents can engage with their children. A control group was not provided videos for home viewing. In laboratory sessions, parent-child interactions were recorded during free play without TV, during the presentation of one of the videos, and immediately after watching. During viewing, interactions decreased in quantity and quality across groups; however, parents used video content as a basis for interaction. Coviewing Sesame Beginnings at home was positively associated with quantity of parent-child interaction during the initial free-play session. Furthermore, the quantity and quality of interactions were greater immediately following viewing of Sesame Beginnings than with Baby Einstein.     

Session duration and the VI response function: Within-session prospective and retrospective effects

Two experiments examined the effects of session duration on responding during simple variable-interval schedules. In Experiment 1, rats were exposed to a series of simple variable-interval schedules differing in both session duration (10 min or 30 min) and scheduled reinforcement rate (7.5 s, 15 s, 30 s, and 480 s). The functions relating response rate to reinforcement rate were predominantly monotonic for the short (10-min) sessions but were predominantly bitonic for the long (30-min) sessions, when data from the entire session were considered. Examination of responding within sessions suggested that differences in the whole-session data were produced by a combination of prospective processes (i.e., processes based on events scheduled to occur later in the session) and retrospective processes (i.e., processes based on events that had already occurred in the session). In Experiment 2, rats were exposed to a modified discrimination procedure in which pellet flavor (standard or banana) predicted session duration (10 min or 30 min). All rats came to respond faster during the short (10-min) sessions than during the first 10 min of the long sessions. As in Experiment 1, the results seemed to reflect the simultaneous operation of both prospective and retrospective processes. The results shed light on the recent controversy over the form of the variable-interval response function by identifying one variable (session duration) and two types of processes (prospective and retrospective) that influence responding on these schedules.     

Step changes in the intertrial interval in the midsession reversal task: Predicting pigeons' performance with the learning-to-time model

Our goal was to assess the role of timing in pigeons' performance in the midsession reversal task. In discrete-trial sessions, pigeons learned to discriminate between 2 stimuli, S1 and S2. Choices of S1 were reinforced only in the first half of the session and choices of S2 were reinforced only in the second half. Typically, pigeons choose S2 before the contingency reverses (anticipatory errors) and S1 after (perseverative errors), suggesting that they time the interval from the beginning of the session to the contingency reversal. To test this hypothesis, we exposed pigeons to a midsession reversal task and, depending on the group, either increased or decreased the ITI duration. We then contrasted the pigeons' performance with the predictions of the Learning-to-Time (LeT) model: In both conditions, preference was expected to reverse at the same time as in the previous sessions. When the ITI was doubled, pigeons' preference reversal occurred at half the trial number but at the same time as in the previous sessions. When the ITI was halved, pigeons' preference reversal occurred at a later trial but at an earlier time than in the previous sessions. Hence, pigeons' performance was only partially consistent with the predictions of LeT, suggesting that besides timing, other sources of control, such as the outcome of previous trials, seem to influence choice.     

Response acquisition and fixed-ratio escalation based on interresponse times in rats

The effectiveness of a fixed‐ratio (FR) escalation procedure, developed by Pinkston and Branch (2004) and based on interresponse times (IRTs), was assessed during lever‐press acquisition. Forty‐nine experimentally naïve adult male Long Evans rats were deprived of food for 24 hr prior to an extended acquisition session. Before the start of the session, three food pellets were placed in the magazine. Otherwise, no magazine training, shaping, nor autoshaping procedure was employed. The first 20 presses each resulted in the delivery of a 45‐mg food pellet. Then, the FR increased (2, 4, 8, 11, 16, 20, 25, 30) when each IRT in the ratio was less than 2 s during three consecutive ratios. Sessions lasted 13 hr or until 500 pellets were earned. On average, rats reached a terminal ratio of 11 (mean) or 16 (median) during the first session. Seven rats reached the maximum value of FR 30 and only one rat did not acquire the response. In most rats, a break‐and‐run pattern of responding characteristic of FR schedules began to develop in this acquisition session. Subsequently, the ratio‐escalation procedure continued during daily 2‐hr sessions. In these sessions, the starting ratio requirement was set at the terminal ratio reached in the previous session. Using this procedure, over half (26) of the rats reached the FR 30 requirement by the fourth session. These data demonstrate that a ratio‐escalation procedure based on IRTs provides a time‐efficient way of establishing ratio responding.     

Social control of form diversity and the emergence of new forms in children's blockbuilding

The blockbuilding behavior of three preschool girls was analyzed in terms of the forms manifest in any completed block construction, and found to contain few different forms in baseline sessions. Social reinforcement, given contingent on the production of any form not previously constructed within the current session (i.e., every first appearance of any form within a session was reinforced but no subsequent appearances of that form within that session were), increased the number of different forms built per sessions. Social reinforcement, given for all second and later appearances within the session, decreased the number of different forms built per session. Furthermore, it was found that new forms (forms never seen before in the child's total prior sequence of blockbuilding sessions) emerged at higher rates during periods of reinforcement of different forms (first appearances) than during periods of baseline or reinforcement of same forms (second and later appearances).     

The creative porpoise: training for novel behavior

Two rough-toothed porpoises (Steno bredanensis) were individually trained to emit novel responses, which were not developed by shaping and which were not previously known to occur in the species, by reinforcing a different response to the same set of stimuli in each of a series of training sessions. A technique was developed for transcribing a complex series of behaviors on to a single cumulative record so that the training sessions of the second animal could be fully recorded. Cumulative records are presented for a session in which the criterion that only novel behaviors would be reinforced was abruptly met with four new types of responses, and for typical preceding and subsequent sessions. Some analogous techniques in the training of pigeons, horses, and humans are discussed.     

A Feasibility Study of Behavioral Activation for Major Depressive Disorder in a Community Mental Health Setting

Behavioral activation (BA) is a well-supported treatment approach, but little research has been conducted on the effectiveness of this treatment within publicly funded community mental health settings. We examined the feasibility of conducting a randomized trial examining the effectiveness of nine sessions of BA as a treatment for major depressive disorder (MDD) in a community mental health clinic (CMHC) setting. Following adaptation of a BA manual and training of BA therapists, 80 patients seeking treatment at a CMHC were randomized, with a 3:1 randomization rate of BA to nine sessions of treatment as usual (TAU). Feasibility assessments indicated that only one eligible patient refused randomization and, of patients who attended at least one session, the median number of sessions was six for the BA group and eight for the TAU group. Of three postbaseline monthly assessments, 71.3% (171/240) were successfully obtained. On average, patients in the BA condition completed homework assignments 83.9% of the time. Treatment fidelity ratings indicated that substantially more BA techniques were delivered in the BA group compared to the TAU group (d = 2.11). Measures of BA mechanisms improved significantly over time and these changes were significantly associated with change in depressive symptoms. These results indicate that it is feasible to conduct a randomized study of BA for MDD in a CMHC setting. In addition, the study reconfirmed the potential importance of theory-relevant BA mechanism variables. Following these findings, further investigation into the effectiveness of BA in this setting is needed.