Generalization of conditioned fear-potentiated startle in humans: experimental validation and clinical relevance

Though generalization of conditioned fear has been implicated as a central feature of pathological anxiety, surprisingly little is known about the psychobiology of this learning phenomenon in humans. Whereas animal work has frequently applied methods to examine generalization gradients to study the gradual weakening of the conditioned-fear response as the test stimulus increasingly differs from the conditioned stimulus (CS), to our knowledge no psychobiological studies of such gradients have been conducted in humans over the last 40 years. The current effort validates an updated generalization paradigm incorporating more recent methods for the objective measurement of anxiety (fear-potentiated startle). The paradigm employs 10, quasi-randomly presented, rings of gradually increasing size with extremes serving as CS+ and CS−. The eight rings of intermediary size serve as generalization stimuli (GSs) and create a continuum-of-similarity from CS+ to CS−. Both startle data and online self-report ratings demonstrate continuous decreases in generalization as the presented stimulus becomes less similar to the CS+. The current paradigm represents an updated and efficacious tool with which to study fear generalization—a central, yet understudied conditioning-correlate of pathologic anxiety.     

The relation of hypertension to cognitive function

Hypertension is an established risk factor for stroke. However, prior to such a major clinical event, hypertension exerts a more subtle impact on the brain that is revealed by diminished cognitive function. Studies comparing the performance of people with high and normal blood pressure levels have shown that high blood pressure or hypertension is related to poorer performance on tests of attention, learning and memory, executive functions, visuospatial skills, psychomotor abilities, and perceptual skills. Hypertension is also predictive of cognitive decline. Variables that may alter (i.e., moderate) the relation of hypertension to cognitive function include age, education, several biological characteristics of hypertension, and the presence of concurrent diseases. Although hypertensives are not clinically impaired, their diminished levels of cognitive performance could affect their perceived quality of life. Various brain mechanisms may explain the relation of hypertension to lower levels of cognitive function. Further understanding of the relation between hypertension and cognition is critical to the preservation of cognitive function across the life span.     

Student Preference for Explicit Timing and Interspersal Procedures as a Function of Math Problem Completion Rates: Testing the Discrete Task Completion Hypothesis

A within-subjects design was used to compare explicit timing and interspersal with college students. Students were given 3 minutes to complete problems on the explicit timing assignment (25 problems, 3 digits –3 digits) and the interspersal assignment (25 similar problems and 10 problems, 1 digit –1 digit). Results indicated that: (a) students completed more total problems during interspersal for both trials, (b) students completed more target problems during explicit timing for the second trial, and (c) students only preferred interspersal for the first trial. The data from trial one fit the discrete task completion hypothesis and matching law, yet the data from trial two do not match as closely (Skinner, 2002). Discussion focuses on continued need for more research on academic interventions, comparing academic interventions, the discrete task completion hypothesis, and the matching law.     

Primary Care Provider Familiarity with Binge Eating Disorder and Implications for Obesity Management: A Preliminary Survey

Current guidelines for the evaluation and treatment of obesity recommend referring individuals with binge eating disorder (BED) to a mental health professional. However, it is unclear how familiar primary care providers are with BED. The purpose of this study was to assess providers' familiarity with BED diagnosis and treatment. Providers in two primary care clinics completed a questionnaire, which assessed perceived familiarity with BED and demonstrated familiarity with BED diagnosis and treatment. Results indicated that 61% of respondents demonstrated familiarity with the essential symptoms of BED, and 80% reported familiarity with the diagnosis of BED. However, 35% of respondents who perceived themselves as familiar with BED did not demonstrate familiarity with the most basic symptoms. These results demonstrate that while many providers in primary care are familiar with BED, steps to improve provider familiarity with the disorder and provide appropriate mechanisms to address BED are warranted.     

Phonological, Semantic, and Mediated Priming in Aphasia

An auditory lexical decision task was conducted to examine rhyme, semantic, and mediated priming in nonfluent and fluent aphasic patients and normal controls. Overall, monosyllabic word targets were responded to faster when preceded by rhyming word and nonword primes than unrelated primes. Similarly, semantically related primes facilitated lexical decisions to word targets. No evidence of mediated priming emerged. Results for individual subjects suggest differences in patterns across the subject groups. Implications of the findings for the integrity of lexical access in aphasic patients are considered.     

CHRONIC SOCIAL STRESS, AFFILIATION, AND CELLULAR IMMUNE RESPONSE IN NONHUMAN PRIMATES

Abstract ——We report the first experimental study of the effect of long–term (over 2 years) exposure to a stressor on cellular immune response Forty–three male cynomolgus monkeys were randomly assigned to stable or unstable social conditions for 26 months The proportion of time spent in affiliative behaviors was assessed by observations made twice weekly T–cell immune response (mitogen–stimulated cell proliferation) was assessed weekly for 3 weeks immediately following the 26–month manipulation The possibility that affiliative behavior represents an attempt to cope with social stress was supported by greater affiliation among animals m the unstable condition than in the stable condition Animals in the unstable condition also demonstrated relatively suppressed immune response More affiliative animals showed enhanced immune response, with the beneficial effects of affiliation occurring primarily among unstable animals The data are interpreted as consistent with the stress–buffering hypothesis, that IS, affiliation protects animals from the potentially pathogenic influences of chronic social stress     

A Family Physician in an Ultraorthodox Jewish Village

The ultraorthodox Jewish community of Kfar Habbad Village is a special minority community in the Israeli context, one with particular needs because of its special religious and social commitments. This paper gives a personal account of a family physician's work in treating this population. It emphasizes the unique role of the doctor in her ongoing interaction with the rabbis of the Village and the doctor's use of community resources in order to meet the special needs of the group.     

Verb generation priming involves conceptual implicit memory

Brain activation patterns differ and generation latencies are reduced when generating verbs to repeated nouns (Raichle et al., 1994). Amnesic participants show normal magnitude of priming (Seger et al., 1997). Despite its importance in neuropsychology, verb generation priming is not well characterized psychologically. Six behavioral studies found that verb generation priming was specific to the verb rather than to the noun or the noun-verb pair, was equivalent after overt or covert generation and after reading verbs or generating verbs, was affected by levels of processing, and transferred completely across languages in bilinguals. These results indicate that verb generation priming involves priming of particular responses and happens at a conceptual level. These findings provide new insights about the significance of brain imaging and neuropsychological studies involving verb generation priming.     

The development of change detection

Changes to a scene often go unnoticed if the objects of the change are unattended, making change detection an index of where attention is focused during scene perception. We measured change detection in school-age children and young adults by repeatedly alternating two versions of an image. To provide an age-fair assessment we used a bimanual choice rather than open-ended verbal responses. The difference in detection speed and accuracy between 50-ms versus 250-ms blank screens between views indexed change detection in short-term visual memory independent of sensory and response processes. Younger children were significantly less efficient than older participants, especially when an object changed color or had a part deleted. Changes in object orientation were detected more readily. These results point to important differences in the perceptual reality of younger and older children.