Control of responding by the location of an auditory stimulus: role of rise time of the stimulus

The control of responding by the location of tone bursts of 0.2- or 50-msec rise time was investigated in three albino rats. The apparatus consisted of an enclosure with two levers, two loudspeakers (in different locations), and a dipper feeder. The animal was exposed to tone bursts from either one or the other of the two speakers, and the speaker through which the tone bursts were delivered on any particular trial alternated in an irregular manner. Responses on one lever were reinforced with food in the presence of tone bursts from one speaker; responses on the second lever were reinforced with food in the presence of tone bursts from the second speaker. Responding came under the control of the location of 4-kHz tone bursts of 0.2-msec rise time within the first session. At this rise time, animals maintained a stable level of correct responding of greater than 95%. When the rise time was increased to 50 msec the percentage of correct responding fell to an average of 80 to 85%. It was concluded that location of an auditory stimulus is a powerful controller of responding in rats and that the degree of control is dependent upon rise time.     

Loss of negative priming following sleep deprivation

It has been argued that one night of sleep loss in young healthy adults produces changes similar to that associated with normal, healthy ageing—in particular, that young sleep-deprived adults perform similarly to 60-year-old sleep-satiated adults on some tasks of frontal lobe function. This proposition was examined using a protocol viewed by many to be a direct probe of nonvolitional attention mechanisms associated with frontal lobe function. A negative priming (NP) procedure was used to compare performance between non-sleep-deprived (NSD) and sleep-deprived (SD, 34 hr) young, healthy adults. This protocol allowed for exploration of two theories of the NP effect based on inhibitory or memorial processes. Under conditions believed to facilitate inhibitory processes a normal NP effect was found for NSD(16 ms) and SD (9 ms) participants. Under conditions believed to rely on memorial processes there was no NPeffect following SD, compared with a normal NP effect for NSD participants (11 ms). Distractor interference was also greater following SD. These findings do not suggest a similar pattern of change following sleep loss in healthy young adults to that of normal, healthy, non-sleep-deprived aged groups.     

Adapting Cognitive Processing Therapy to Treat Co-Occurring Posttraumatic Stress Disorder and Mild Traumatic Brain Injury: A Case Study

This case study aims to provide evidence for the effectiveness of adapting a particular manualized cognitive behavioral therapy intervention to treat co-occurring posttraumatic stress disorder (PTSD) and mild traumatic brain injury (mTBI). This study presents the treatment of a woman who experienced co-occurring mTBI and PTSD following a motor vehicle accident, a dual diagnosis that was established through a flexible assessment approach involving interviews as well as standardized psychological, neuropsychological, and neurobehavioral testing. Treatment planning led to a-priori adaptation of Cognitive Processing Therapy (CPT) to treat both her PTSD symptoms and the sequelae associated with her mTBI. The therapist maintained fidelity to the manualized structure and content of CPT protocol, adapting portions of the treatment to add specific emphasis on issues of identity confusion and role loss in service of addressing these common functional impairments that can accompany mTBI. Discussion focuses on application of CPT for future treatment of comorbid PTSD and TBI amidst complicating factors, including role losses and medical and safety issues. This case study is especially relevant due to the prevalence of co-occurring PTSD and TBI across a variety of populations.     

Providers’ Perceptions and Practices Regarding <Emphasis Type="BoldItalic">BRCA1/2</Emphasis> Genetic Counseling and Testing in African American Women

We examined healthcare providers’ perceptions of genetic counseling and testing in African American women at moderate to high-risk of carrying a BRCA1/2 mutation. We conducted 20 in-depth interviews with genetic counselors (n = 5), medical oncologists (n = 8), obstetrician/gynecologists (n = 2) and surgeons (n = 5). Interviews were audiotaped, transcribed and independently coded by two individuals using a content analysis approach. Seven themes emerged relevant to providers’ perceptions of African American women’s use of BRCA1/2 genetic services: access factors, cultural beliefs and preferences, effects of testing, patient motivators for genetic counseling and testing, patient-provider communication, reasons for provider referral, and reasons for patient refusal. Providers identified individual- and system-level barriers to African American women’s use of genetic services, including lack of follow-up after referrals to genetic specialists and challenges to obtaining financial coverage for under- and uninsured high-risk women. Results have implications for physician and patient education regarding appropriate referrals to and uptake of genetic services in at-risk African American women.     

Caudate nucleus-dependent response strategies in a virtual navigation task are associated with lower basal cortisol and impaired episodic memory

The present research examined the relationship between endogenous glucocorticoids, navigational strategies in a virtual navigation task, and performance on standard neuropsychological assessments of memory. Healthy young adult participants (N = 66, mean age: 21.7) were tested on the 4 on 8 virtual maze (4/8 VM) and standard neuropsychological tests such as the Rey-Osterrieth Complex Figure (RO) and the Rey Auditory Verbal Learning Task (RAVLT), which measure episodic memory. The 4/8 VM differentiates between navigational strategies, where participants either use a hippocampal-dependent spatial strategy by building relationships between landmarks, or a caudate nucleus-dependent stimulus–response strategy by automatizing a pattern of open and closed arms to learn the location of objects within the maze. Degree of stress was assessed by administering the Perceived Stress Scale (PSS) questionnaire. Cortisol samples were taken on two consecutive days upon waking, 30 min after waking, at 11 am, 4 pm, and 9 pm. There was a significant difference in basal levels of cortisol between spatial and response learners. Interestingly, response learners had significantly lower cortisol levels throughout the day. The two groups did not differ in terms of perceived stress as measured with the PSS questionnaire. Moreover, there was no significant correlation between PSS scores and salivary cortisol levels, indicating that the higher cortisol levels in the spatial group were not associated with greater perceived stress. In addition, participants who spontaneously used a spatial strategy performed significantly better on the RAVLT and RO. These data indicate that the cortisol levels in the spatial group may be optimal in terms of episodic memory performance whereas the cortisol levels in the response group may be associated with poorer memory. These results are suggestive of an inverted U-shaped curve describing the effects of basal levels of circulating cortisol on memory in young adults.     

Effects of action planning and coping planning within the theory of planned behaviour: A physical activity study of patients undergoing haemodialysis

Objective

Patients on dialysis have low physical activity levels. The aim of the study was to examine the validity of action planning and coping planning within the theory of planned behaviour framework, for predicting physical activity behaviour of patients on haemodialysis.

Design

This is a prospective study design.

Methods

One hundred and forty-four patients who were undergoing haemodialysis were selected from dialysis centres. The mean age of the patients was 56.61 (SD = 11.38) years. The patients completed a questionnaire including variables from the theory of planned behaviour, action planning and coping planning. Physical activity was prospectively assessed at 4-weeks with the validated International Physical Activity Questionnaire self-report measure. A hierarchical regression analysis was performed to examine the effects of action planning and coping planning on physical activity behaviour.

Results

There was a main effect for coping planning but not for action planning. Moreover, the analyses resulted in a significant amount of incremental variance accounted for by the interaction of coping planning and intention.

Conclusion

Results suggest the combination of high levels of coping planning and intention is associated with increases in physical activity.