Distinct mechanisms underlying memory modulation after the first and the second session of two avoidance tasks

Rats were subjected to three consecutive sessions, one session per day, of either a step-down inhibitory avoidance task using a 60-Hz. 0.3-mA footshock, or a two-way active avoidance task using 20 presentations of a 5-s, 1-kHz tone and a 0.3-mA footshock. After either the first or the second training session animals received an intraperitoneal injection of ACTH (0.2 microgram/kg), epinephrine-HCl (5.0 micrograms/kg), or naloxone-HCl (0.8 mg/kg). All these treatments caused memory facilitation on both tasks when administered after the first training session. When administered after the second training session only ACTH and adrenaline were effective, on both tasks. As previous physiological and pharmacological reports point to the activation of the brain beta-endorphin system after the first, but not the second, session of a task, we propose that (a) memory facilitation by naloxone depends on the previous activation of the brain beta-endorphin system; and (b) memory facilitation due to ACTH or epinephrine does not depend on the opioid activity, so their effects are expressed after both the first and the second training sessions. It was also observed that the enhancement of performance in the second training session due to post-training facilitatory treatments carried over to the test session. These results suggest that some form of consolidation occurs both after the first and after the second training session.     

Effects of imaginal exposure to feared disasters in obsessive-compulsive checkers

The combined effects of imaginal exposure to feared catastrophes and in vivo exposure to external stimuli were compared with the effects of in vivo exposure alone in 15 obsessive-compulsives with checking rituals. The first group received 90 min of uninterrupted exposure in imagination, which concentrated mainly on disastrous consequences, followed by 30 min of exposure in vivo to stimuli-situations which triggered rituals. The second group was given 2 hr of exposure in vivo only. Both groups were prevented from performing rituals. Treatment consisted of 10 daily sessions within a 2 week period.Assessments were conducted before and after treatment and at follow-up ranging from 3 months to 2.5 yr with a mean of 11 months. At post-treatment both groups improved considerably and did not differ. But at follow-up those who received imaginal and in vivo exposure maintained their gains, whereas the group who were treated by exposure in vivo alone evidenced partial relapse on four of the six dependent measures. The results tend to indicate that a closer match between a patient's internal fear model and the content of exposure enhances long term treatment efficacy.     

Brief Imaginal Exposure for PTSD: Trajectories of Change in Distress

Preliminary evidence shows that brief, condensed imaginal exposure only interventions can be effective in the treatment of PTSD, but we need to understand its mechanisms of action. Consistent with extinction learning and retrieval processes, the present study examined whether a pattern of between-session distress reduction observed during standard prolonged exposure (PE) therapy would be observed and predict outcome. Sixty-three patients with PTSD were enrolled in two clinical trials using our treatment protocol consisting of six daily 50-min sessions focusing on imaginal exposure and processing only. Individual patient trajectories of distress reduction were examined over the course of the five imaginal exposure sessions (Sessions 2-6). Overall, significant linear distress reduction was observed for anticipatory (d = 1.18), peak (d = 1.83), and ending imaginal exposure distress (d = 1.21). Consistent with extinction learning, the steeper slope of peak distress (d = 1.03) and end distress (d = 0.68) across imaginal exposure sessions strongly predicted decreases in PTSD symptoms. Distress reduction across sessions was predicted by higher baseline avoidance and hyperarousal but not reexperiencing symptoms. This condensed format of daily 50-min sessions without in vivo exposure may be operating via similar extinction learning processes as longer protocols. Our clinical observations suggest that the brief daily format may offer the advantage of allowing each session to build on the previous one to promote meaningful shifts in the retrieval of the trauma memory. Brief imaginal exposure and processing may be a viable option for PTSD patients in settings where brief interventions are needed. Understanding potential change processes and baseline predictors of change brings us closer toward precision medicine in treating PTSD.     

A temporal limit on the effect of future food on current performance in an analogue of foraging and welfare

Rats obtained access to food twice each 24-hour period. The first session was a work session in which food was available on a progressive-ratio schedule. During the second session, which occurred between 1 and 23 hours after the work session, food was freely available up to a fixed total intake each 24 hours. The situation resembled elements of several real world circumstances, including the choice between continuing to forage in a rapidly depleting patch and waiting for a better patch, and between working now and receiving a guaranteed income later. The purpose of the experiment was to explore the time period over which future access to reward could affect current responding. Contrary to what might be expected from recent theorizing, anticipation of future food delayed by an hour or more after the start of the work session had no effect on current performance. Food intake was high and constant during work sessions except for a prefeeding effect that occurred when the free session closely preceded the next day's work session. Also, an increase in the difficulty of the work schedule increased the amount of work and the maximum price paid for food as if the work session were the only time food was available. The results indicate the importance of considering temporal limits in theories that require animals to integrate input over time to determine the allocation of resources among alternatives.     

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.     

Stock optimizing: maximizing reinforcers per session on a variable-interval schedule.

In Experiment 1, 2 monkeys earned their daily food ration by pressing a key that delivered food according to a variable-interval 3-min schedule. In Phases 1 and 4, sessions ended after 3 hr. In Phases 2 and 3, sessions ended after a fixed number of responses that reduced food intake and body weights from levels during Phases 1 and 4. Monkeys responded at higher rates and emitted more responses per food delivery when the food earned in a session was reduced. In Experiment 2, monkeys earned their daily food ration by depositing tokens into the response panel. Deposits delivered food according to a variable-interval 3-min schedule. When the token supply was unlimited (Phases 1, 3, and 5), sessions ended after 3 hr. In Phases 2 and 4, sessions ended after 150 tokens were deposited, resulting in a decrease in food intake and body weight. Both monkeys responded at lower rates and emitted fewer responses per food delivery when the food earned in a session was reduced. Experiment 1's results are consistent with a strength account, according to which the phases that reduced body weights increased food's value and therefore increased subjects' response rates. The results of Experiment 2 are consistent with an optimizing strategy, because lowering response rates when food is restricted defends body weight on variable-interval schedules. These contrasting results may be attributed to the discriminability of the contingency between response number and the end of a session being greater in Experiment 2 than in Experiment 1. In consequence, subjects lowered their response rates in order to increase the number of reinforcers per session (stock optimizing).     

Incubation of conditional suppression is an associatively-based phenomenon

Ten rats were deprived of water and trained to lick a tube for saccharin reinforcement. In each of the two sessions that followed, the rats received six contiguous pairings of a 30-second illumination of the houselight and a 0.75 second, 0.10 mA electric shock while licking. No sign of conditioning was observed during the first experimental session, but profound conditioning was observed on the first and subsequent trials of the second conditioning session. No comparable change in the rate of licking was observed in groups of rats that received only presentations of the visual stimulus, only presentations of the electric shock, or random presentation of the visual stimulus and electric shock during the first conditioning session. These data establish that the incubation of conditional suppression is an associative phenomenon.     

Exposure in vivo vs social skills training for social phobia: long-term outcome and differential effects

This study examined the long-term effectiveness of specific exposure in vivo (individual IE or group GE) and of office-based social skills training (group SST) in two groups of patients with social inhibition (primary social skills deficits or primary social phobia). Seventy-eight outpatients were divided into these two subgroups according to clinical assessment. Twenty-seven patients received SST which consisted of 25 twice a week 90-min group sessions: 32 patients received GE and 17 IE. Exposure in vivo consisted of 4 weekly (8-hr in the group condition included 2 hr discussion; 3 hr in the individual condition included 1 hr discussion) sessions. Self-rating-assessments were carried out at pre- and post-treatment, at 3 months- and 2.5 yr follow-up. The general results indicate that all three treatment modes led to clinically and statistically-significant improvements in the main problem area (social anxiety, skills deficits), in other neurotic complaints (depression, obsessions, psychosomatic complaints) and in attribution-style. Patients with the diagnosis of primary phobia seemed to get the same profit from either treatment and showed slightly better gains (in all treatment modalities) than patients with skills deficits at long-term follow-up. Within the subgroup with skills deficits there was a tendency for superior outcome of group exposure. These results and recommendations for future research are discussed.     

Treating PTSD in active duty service members using cognitive processing therapy or prolonged exposure therapy: Examining everyday practice at a military outpatient clinic

The Institute of Medicine has stressed the need for evaluations of evidence-based treatments (EBTs) for posttraumatic stress disorder (PTSD) among active duty service members (AD) using a variety of evaluation approaches (Institute of Medicine, 2012). The current study examined the clinical files of 134 service members who completed treatment for PTSD using either prolonged exposure (PE) or cognitive processing therapy at an outpatient clinic. At the completion of each session, therapists made a clinical rating as to whether or not the session was protocol adherent. The total number of treatment sessions and the proportion of sessions rated as being protocol adherent were calculated. Multi-level models estimated the change in patient PTSD and other psychological symptoms over time as a function of clinician-rated protocol adherence and total number of sessions. Approximately 65% of clinic encounters were rated by therapists as being protocol adherent. Significant reductions in PTSD and psychological symptoms were associated with protocol adherence, and this was particularly true for patients who began treatment above clinical thresholds for both PTSD and other psychological symptoms. However, as the number of sessions increased, the impact of protocol adherence was attenuated. Patient characteristics, including gender, ethnicity, and co-morbidity for other psychiatric disorders were not related to symptom change trajectories over time. These findings suggest that protocol adherence and efficiency in delivery of EBTs for the treatment of PTSD with AD is critical.     

When to Change the Treatment Plan: An Analysis of Diminishing Returns in VA Patients Undergoing Prolonged Exposure and Cognitive Processing Therapy

Evidence-based treatments for posttraumatic stress disorder (PTSD) often produce significant symptom reduction within eight sessions. However, some patients take longer to respond and a better understanding of predictors of later response can help guide treatment. In the current study, the cohort consisted of all VA patients with a PTSD diagnosis who received at least eight sessions of documented evidence-based treatment within a 6-month period in FY16-FY17 and had at least two PTSD symptom assessments. We examined the proportion of patients who achieved meaningful change (defined as at least 50% reduction in self-reported PTSD symptoms), both within the first eight sessions and subsequently. Fourteen percent of patients achieved meaningful change within eight sessions and 10% subsequently. Symptom change within the first eight sessions was highly predictive of subsequent change. Those who experienced at least 20% symptom reduction by session eight were twice as likely to subsequently achieve meaningful change as compared with all patients who continued treatment. Patients receiving service-connected disability compensation were less likely and White patients more likely to achieve meaningful change. Without some degree of symptom reduction by session eight, patients are unlikely to achieve meaningful change if treatment is not enhanced or changed.     

A Video Recall Study of In‐session Changes in Sentiment Override

This study examines in‐session changes in sentiment override over the first three sessions of couple therapy. Couples viewed a video recording of therapy sessions immediately after each of the first three sessions and continuously rated their level of sentiment override. Ninety‐eight changes were randomly chosen for analysis. Three talk turns prior to each change was coded using the Family Relational Communication Control Coding System. Results show that changes in sentiment override occur frequently. Repeated incidents of communication control were related to negative change in sentiment override for females. Repeated incidents of being left out of the conversation were related to negative changes in sentiment override for females and positive changes for males.     

Punishment shock intensity and basal skin resistance

The relationship between punishment shock intensity and basal skin resistance (BSR) was investigated in two sessions with human females selected for their ability to maintain a fairly substantial operant rate under a wide range of shock intensities. In both sessions each button-pressing response was reinforced with a counter tally. Subjects were paid one cent for each 20 counts. In session 1, punishment followed each response during alternate 4-min periods; in session 2 punishment was programmed in all 4-min periods. Shock intensities were presented randomly among the 4-min shock periods, with the restriction that the first three presentations occurred in ascending order. Operant responding showed some suppression at higher shock intensities in session 1, with substantial recovery in most subjects during session 2. Respondent behavior was characterized by greater activity at successively higher intensities, with recovery at all shock levels, especially the lowest levels, apparent during the second session.     

A forty-three day avoidance session

A single Sprague-Dawley rat was subjected to an extended discriminated avoidance session in effect continuously for over 1000 hr (43 days). The longest possible shock-free interval that the subject could obtain without responding was 5 min. Since the subject did not sleep through shock, all resting or sleeping was interrupted at least once every 5 min by either a response or a shock. Neither the experimental (avoidance) animal nor a second animal which received all shocks not avoided by the first, gave any appearance of ill effects from the protracted session.     

Evaluating Marital Therapy: A Hospital and Community Study

The study investigated the application of marital therapy using three contrasting clinical approaches: conjoint treatment, couples groups, and treating the partner alone. Thirty-six couples comprised the research sample, with eighteen couples being treated in each of two NHS treatment settings. The duration of the treatment was ten weekly sessions each lasting one hour, and couples were followed up six months after termination. Outcome evaluations included marital satisfaction, sexual adjustment, and an assessment of target problems. The analysis of the results showed no significant difference between groups at the post-treatment and follow-up assessments. There was, however, a significant difference in the rates of change between experimental groups. The implications of these results are discussed.     

A Review of: “Greenwald,R. (2009). Treating Problem Behaviors: A Trauma-Informed Approach.”

This single-case-design experiment examined an intervention to decrease bed-sharing in children, ages 2 through 6. Three sessions were conducted with each parent. At the first session, parents described bed-sharing history and began collecting baseline data. At the second session, parents were instructed to employ the intervention. At the third session, parents were interviewed and offered continued support, if needed. Participants included three children who slept with their parents 4 or more nights per week. The intervention resulted in a substantial decrease in bed-sharing behavior for all participants, and parents reported being satisfied with the intervention.     

Beta-endorphin enhancement of retrieval in a three-session paradigm

Rats were submitted to three consecutive sessions, one session per day, of step-down inhibitory avoidance task (60-Hz, 0.3-mA footshock) or of two-way active avoidance task (25 trials of a 5-s, 1-kHz tone and a 0.4-mA footshock). Animals received intraperitoneal (ip) injections of saline or beta-endorphin (2.0 micrograms/kg) before or after the second session and before the third session. beta-Endorphin given before either the second or the third session improved retention of both tasks, while its administration after the second session had no effect upon performance on both tasks. In Experiment 2, it was shown that rats receiving naloxone (0.2 mg/kg) ip after the first session did not exhibit the enhancement of retrieval by beta-endorphin administration before the second session, so a non-state-dependent improvement of retrieval by the opioid seems to be unlikely. In view of these results we can propose that the presession retrieval enhancing effect of beta-endorphin is due to an endogenous state dependency on the opioid that can be expressed either in the second or in the third session of aversive tasks.     

BIOFEEDBACK AND RATIONAL-EMOTIVE THERAPY IN THE MANAGEMENT OF MIGRAINE HEADACHE

Twenty-four migraine patients were randomly assigned to one of four conditions: (a) self-monitoring of headache activity (waiting list), (b) frontalis EMG biofeedback, (c) digit temperature biofeedback, and (d) digit temperature biofeedback plus Rational-Emotive Therapy (RET). Bidirectional control over the target physiological response was assessed through a reversal design in each session. Following at least a four-week baseline, the three biofeedback groups received 8 to 10, 30-minute sessions of bidirectional biofeedback training, scheduled twice a week. Subjects in the combined digit temperature biofeedback plus RET group received three 40-minute sessions of RET as an addition to the third, fifth, and seventh biofeedback sessions. Records of daily home practice were kept throughout treatment and three-month followup. Subjects on the waiting list monitored headaches for at least five months, corresponding to “baseline”, “treatment”, and three-month followup. Digit temperature biofeedback alone and in conjunction with RET did not prove to be more effective than the control conditions. All the EMG subjects reduced headache activity to two-thirds or less of the baseline level by the third month of followup. Bidirectional digit temperature performance did not improve with training, was demonstrated in only 33% of the biofeedback sessions, was not maintained over time, and was unrelated to improvement in headache activity. EMG subjects reported biofeedback performance to be an easier task and met the performance criterion on 85% of the sessions. The frequency of home practice contributed over 55% of the variance in retrospective estimates of headache improvement but was not related to changes in daily records of headache activity.     

The effect of acceleration on food-reinforced DRL and FR

Performance on DRL 10 sec and FR 5 was studied after exposure to acceleration. After four rats, two on each of the above schedules, had stabilized they were exposed to 5 hr of acceleration at 5 G immediately before daily experimental sessions. Food intake was also studied in rats given access to food daily in their home cages and exposed to acceleration immediately before the free-feeding session. Weight gain of free-feeding animals and reinforcement intake of experimental animals dropped after acceleration. Over-all response rate on the FR was depressed markedly by acceleration but local response rates did not appear to be affected. IRT distributions of DRL sessions after acceleration were markedly shifted toward the long intervals. A sequential plot of IRTs on acceleration days showed an altered, but relatively stable, temporal patterning of responses followed by an abrupt return to the normal baseline toward the end of the session.     

Counseling dropout relative to client attractiveness,disturbance, and expected number of sessions

Participants were 12 counseling center psychologist and thir 257 college-student clients. Immediately after intake, clients indicated whether or not they would make an additional appointment, their reasons for not making another appointment, and the estimated number of sessions they would attend. Counselors rated clients' attractiveness and disturbance and estimated the number of sessions they would have with each client. Clients who did not make a second appointment were generally satisfied with the help they received in one session. Client estimates were more predictive than counselor estimates of actual number of sessions. Relative to less attractive and disturbed clients, more attractive and disturbed clients made and kept post-intake appointments.     

Classical Delay Eyeblink Conditioning in in 4- and 5-Month-Old Human Infants

Abstract-Simple delay classical eyeblink conditioning, using a tone conditioned stimulus (CS) and airpuff unconditioned stimulus (US), was studied in cross-sectional samples of 4- and 5-month-old healthy, full-term infants. Infants received two identical training sessions, 1 week apart. At both ages, infants experiencing paired tones and air-puffs demonstrated successful conditioning over two sessions, relative to control subjects who had unpaired training. Conditioning was not evident, however, during the first session. Two additional groups of 5-month-olds received varied experiences during Session 1, either unpaired presentations of the CS and US or no stimulus exposure, fol-lowed by paired conditioning during Session 2. Results from these groups suggest that the higher level of conditioning observed following two sessions of paired conditioning was not the result of familiarity with the testing environment or the stimuli involved but, rather, the result of retention of associative learning not expressed during the first conditioning session.