Evidence against integration of spatial maps in humans

A dynamic 3-D virtual environment was constructed for humans as an open-field analogue of Blaisdell and Cook's (2005) pigeon foraging task to determine if humans, like pigeons, were capable of integrating separate spatial maps. Participants used keyboard keys and a mouse to search for a hidden goal in a 4×4 grid of raised cups. During Phase 1 training, a goal was consistently located between two landmarks (Map 1: blue T and red L). During Phase 2 training, a goal was consistently located down and left of a single landmark (Map 2: blue T). Transfer trials were then conducted in which participants were required to make choices in the presence of the red L alone. Cup choices during transfer assessed participants’ strategies: association (from Map 1), generalization (from Map 2), or integration (combining Map 1 and 2). During transfer, cup choices increased to a location which suggested an integration strategy and was consistent with results obtained with pigeons. However, additional analyses of the human data suggested participants initially used a generalization strategy followed by a progressive shift in search behavior away from the red L. This shift in search behavior during transfer was responsible for the changes in cup choices across transfer trials and was confirmed by a control condition. These new analyses offer an alternative explanation to the spatial integration account proposed for pigeons.Electronic Supplementary Material Supplementary material is available for this article at     

Acute treatment of inpatients with psychotic symptoms using Acceptance and Commitment Therapy: pilot results

Cognitive behavior therapy (CBT) has been demonstrated in a number of randomized controlled trials to be efficacious as an adjunctive treatment for psychotic disorders. Emerging evidence suggests the usefulness of CBT interventions that incorporate acceptance/mindfulness-based approaches for this population. The current study extended previous research by Bach and Hayes (2002. The use of Acceptance and Commitment Therapy to prevent the rehospitalization of psychotic patients: A randomized controlled trial. Journal of Consulting and Clinical Psychology, 70, 1129-1139) using Acceptance and Commitment Therapy (ACT) in the treatment of psychosis. Psychiatric inpatients with psychotic symptoms were randomly assigned to enhanced treatment as usual (ETAU) or ETAU plus individual sessions of ACT. At discharge from the hospital, results suggested short-term advantages in the ACT group in affective symptoms, overall improvement, social impairment, and distress associated with hallucinations. In addition, more participants in the ACT condition reached clinically significant symptom improvement at discharge. Although 4-month rehospitalization rates were lower in the ACT group, these differences did not reach statistical significance. Decreases in the believability of hallucinations during treatment were observed only in the ACT condition, and change in believability was strongly associated with change in distress after controlling for change in the frequency of hallucinations. Results are interpreted as largely consistent with the findings of Bach and Hayes and warrant further investigations with larger samples.     

Hypnotherapy and cognitive behaviour therapy of acute stress disorder: a 3-year follow-up

The long-term benefits of cognitive behaviour therapy (CBT) for trauma survivors with acute stress disorder were investigated by assessing patients 3 years after treatment. Civilian trauma survivors (n=87) were randomly allocated to six sessions of CBT, CBT combined with hypnosis, or supportive counselling (SC), 69 completed treatment, and 53 were assessed 2 years post-treatment for post-traumatic stress disorder (PTSD) with the Clinician-Administered PTSD Scale. In terms of treatment completers, 2 CBT patients (10%), 4 CBT/hypnosis patients (22%), and 10 SC patients (63%) met PTSD criteria at 2-years follow-up. Intent-to-treat analyses indicated that 12 CBT patients (36%), 14 CBT/hypnosis patients (46%), and 16 SC patients (67%) met PTSD criteria at 2-year follow-up. Patients who received CBT and CBT/hypnosis reported less re-experiencing and less avoidance symptoms than patients who received SC. These findings point to the long-term benefits of early provision of CBT in the initial month after trauma.     

Prediction of treatment outcome among patients with irritable bowel syndrome treated with group cognitive therapy

Using a sample of over 125 patients with irritable bowel syndrome (IBS) who were treated with cognitive therapy administered in small groups, we sought to predict end of treatment and 3-month follow-up improvement in two changes indices of gastrointestinal (GI) symptoms (Pain/Discomfort Index which assessed change in abdominal pain, abdominal tenderness and bloating and Bowel Regularity Index which assessed change in diarrhea and constipation). We also sought to predict scores on IBS specific quality of life (QOL) and overall level of psychological distress using the Global Severity Index (GSI) of the Brief Symptom Inventory (BSI). Significant, but modest, levels of prediction were found for prediction of improvement in GI symptoms (4-15% of variance). Stronger significant prediction was obtained for the QOL and global psychological distress measure with R(2)'s ranging from 0.36 to 0.50. A wide variety of demographic, GI symptom, psychological status and psychiatric status variables entered the final prediction equations.     

Do obsessional beliefs discriminate OCD without tic patients from OCD with tic and Tourette's syndrome patients?

There is considerable overlap in symptomatology between Tourette's syndrome (TS) and obsessive-compulsive disorder (OCD). Increased rates of tics are found in OCD and up to 60% obsessive-compulsive symptoms in TS. However, in OCD obsessive-compulsive symptoms are more often anxiety-related and, as a consequence, aimed at anxiety-reduction, whereas in TS these symptoms are more stimulus-bound. Therefore, it is of clinical interest to study whether these phenomenological differences are reflected in differences between dysfunctional cognitions accompanying OC symptoms in OCD with or without tics and TS. Current cognitive theory of OCD ascertains that specific dysfunctional beliefs are important in the etiology and maintenance of OCD. To assess these beliefs, the obsessive-compulsive beliefs questionnaire-87 (OBQ-87) has been developed. In the present study, OBQ-87 scores of OCD patients without tics, OCD with tics, and TS (without OCD) patients were compared to those of normal controls. Results: OCD without tic patients exhibited higher OBQ-87 scores than TS patients. No differences were found between OCD with or without tic patients on any of the OBQ-87 subscales. These results suggest that: (1) dysfunctional beliefs have no discriminative power with respect to OCD with or without tic patients; (2) the direct relationship between types of OC symptoms and specific dysfunctional beliefs is questionable. Therefore, one can doubt the specificity of cognitive theory of OCD to explain specific OC behavior.     

Suboptimal tradeoffs in information seeking

Explicit information-seeking actions are needed to evaluate alternative actions in problem-solving tasks. Information-seeking costs are often traded off against the utility of information. We present three experiments that show how subjects adapt to the cost and information structures of environments in a map-navigation task. We found that subjects often stabilize at suboptimal levels of performance. A Bayesian satisficing model (BSM) is proposed and implemented in the ACT-R architecture to predict information-seeking behavior. The BSM uses a local decision rule and a global Bayesian learning mechanism to decide when to stop seeking information. The model matched the human data well, suggesting that adaptation to cost and information structures can be achieved by a simple local decision rule. The local decision rule, however, often limits exploration of the environment and leads to suboptimal performance. We propose that suboptimal performance is an emergent property of the dynamic interactions between cognition and the environment.     

Re-visiting the competence/performance debate in the acquisition of the counting principles

Advocates of the "continuity hypothesis" have argued that innate non-verbal counting principles guide the acquisition of the verbal count list (Gelman & Galistel, 1978). Some studies have supported this hypothesis, but others have suggested that the counting principles must be constructed anew by each child. Defenders of the continuity hypothesis have argued that the studies that failed to support it obscured children's understanding of counting by making excessive demands on their fragile counting skills. We evaluated this claim by testing two-, three-, and four-year-olds both on "easy" tasks that have supported continuity and "hard" tasks that have argued against it. A few noteworthy exceptions notwithstanding, children who failed to show that they understood counting on the hard tasks also failed on the easy tasks. Therefore, our results are consistent with a growing body of evidence that shows that the count list as a representation of the positive integers transcends pre-verbal representations of number.     

Treatment of obsessive-compulsive disorder: cognitive behavior therapy vs. exposure and response prevention

The efficacy of contemporary cognitive therapy for obsessive–compulsive disorder (OCD) has only recently been investigated. The current study compares exposure and response prevention (ERP) and cognitive behavior therapy (CBT) delivered in an individual format. Participants were randomly assigned to the 12 consecutive-week CBT or ERP treatment. Based on 59 treatment completers, there was no significant difference in YBOCS scores between CBT and ERP at post-treatment or at 3-month follow-up. A higher percentage of CBT participants obtained recovered status at post-treatment (67%) and at follow-up (76%), compared to ERP participants (59% and 58%, respectively), but the difference was not significant. Effect sizes (ESs) were used to compare the results of the current study with a previous study conducted at our center that utilized group CBT and ERP treatments, as well as other controlled trials that have compared CBT and ERP. The significance of these results is discussed and a comparison is made with the existing literature.     

Memory and interpretation of visual representations of threat in socially anxious and nonanxious individuals

The present study was designed to replicate and extend results reported by Brendle and Wenzel (Behav. Res. Ther. 42 (2004) 155), who found that socially anxious individuals accurately recalled threat-relevant information but subsequently imposed a biased interpretation upon that same material, using more ecologically valid stimuli. Socially anxious (n=37) and nonanxious (n=47) individuals viewed two positive, two negative, and two neutral video vignettes and completed two cognitive tasks assessing memory and interpretation of factual details immediately and after 48 h. Similar to the results reported by Brendle and Wenzel (2004), socially anxious and nonanxious individuals did not differ in their memory for details that had been presented in the vignettes. However, socially anxious individuals made more negative interpretations of details included in the vignettes than nonanxious individuals, although unlike Brendle and Wenzel (2004), they did not demonstrate the tendency to make less positive interpretations. It is concluded that socially anxious individuals are characterized by interpretation biases when presented with threat-relevant information, and there is no evidence to suggest that they are characterized by memory biases for threat-relevant information.     

Cognitive therapy for post-traumatic stress disorder: development and evaluation

The paper describes the development of a cognitive therapy (CT) program for post-traumatic stress disorder (PTSD) that is based on a recent cognitive model (Behav. Res. Therapy 38 (2000) 319). In a consecutive case series, 20 PTSD patients treated with CT showed highly significant improvement in symptoms of PTSD, depression and anxiety. A subsequent randomized controlled trial compared CT (N = 14) and a 3-month waitlist condition (WL, N = 14). CT led to large reductions in PTSD symptoms, disability, depression and anxiety, whereas the waitlist group did not improve. In both studies, treatment gains were well maintained at 6-month follow-up. CT was highly acceptable, with an overall dropout rate of only 3%. The intent-to-treat effect sizes for the degree of change in PTSD symptoms from pre to post-treatment were 2.70-2.82 (self-report), and 2.07 (assessor-rated). The controlled effect sizes for CT versus WL post-treatment scores were 2.25 (self-report) and 2.18 (assessor-rated). As predicted by the cognitive model, good treatment outcome was related to greater changes in dysfunctional post-traumatic cognitions. Patient characteristics such as comorbidity, type of trauma, history of previous trauma, or time since the traumatic event did not predict treatment response, however, low educational attainment and low socioeconomic status were related to better outcome.