Mechanisms underlying working memory for novel information

In this Opinion article we describe a theory that the brain mechanisms underlying working memory for novel information include a buffer in parahippocampal cortices. Computational modeling indicates that mechanisms for maintaining novel information in working memory could differ from mechanisms for maintaining familiar information. Electrophysiological data suggest that the buffer for novel information depends on acetylcholine. Acetylcholine activates single-cell mechanisms that underlie persistent spiking of neurons in the absence of synaptic transmission, allowing maintenance of information without prior synaptic modification. fMRI studies and lesion studies suggest that parahippocampal regions mediate working memory for novel stimuli, and the effects of cholinergic blockade impair this function. These intrinsic mechanisms in parahippocampal cortices provide an important alternative to theories of working memory based on recurrent synaptic excitation.     

Same-sex couple perceptions of family support: a consensual qualitative study

Few studies have examined the family context in which same-sex couples negotiate their lives and relationships. Consensual qualitative research methods (Hill, Thompson, & Williams, 1997) were used to analyze 14 same-sex couples' conversations about family support. Couples perceived that their families are positively supportive, non-supportive, or ambivalent in their support. These perceptions led to positive or negative emotional reactions in the couple members and to specific coping. The majority of couples perceived that family support (or lack of support) had an effect on the quality of their couple relationship. No general or typical response strategies to lack of family of origin support emerged, suggesting a lack of models or norms for same-sex couples. The implications for psychotherapeutic interventions with same-sex couples are discussed.     

Medical Students' Perceptions of and Willingness to Treat Patients Who Are HIV Infected1

The purpose of this study is to examine the independent and joint influences of a patient's mode of acquisition of illness (blood transfusion vs. multiple sexual partners), attributions of responsibility (self-blame vs. chance blame), and sexual orientation (homosexual vs. heterosexual) on female and male medical students' attitudes toward and willingness to treat a patient who is HIV infected. One hundred nineteen 1st through internship-year medical students were randomly assigned to read and respond to case vignettes. Greater consistency between attribution of blame and mode of acquisition was related to more positive perceptions. Furthermore, the patient's sexual orientation influenced the providers' willingness to offer treatment, particularly for male medical students. Implications concerning health practices and medical education are considered.     

Evidence for frames of reference based on pursuit eye movements

Lighted points that moved as if located on the rim of a rolling wheel were displayed to subjects whose task was to describe the pattern they perceived. The perceived patterns could be classified into one of four categories ranging from cycloidal to circular motion. Pursuit eye movements were controlled by having subjects track a fixation point that moved in the direction of the rolling wheel on a path just above the wheel’s rim. With respect to the translatory velocity of the rolling wheel, the velocity of the fixation point was 100%, 67%, 33%, or 0% (i.e., stationary). The patterns traced out by the points on the wheel were perceived to become increasingly circular as pursuit eye movements more closely matched the translatory speed of the rolling wheel. This is taken to support Stoper’s hypothesis that pursuit eye movements can establish a frame of reference for motion analysis.     

Interal locus of control as a value

Internal and external subjects, who previously filled out Rotter's (1966) I-E scale, were asked to score the I-E scale of “another student”. Subjects were exposed to “an other's” score of either 0, 5, 10, 16, or 23, and were asked to rate themselves and the “other” on an evaluative questionnaire. It was predicted that ratings of the “other” would increase in positivity to the extent the “other” scored as an internal. A reverse direction was predicted for an index of negative evaluations. The predictions were confirmed. The results suggest that internal locus of control is a societal value. The findings did not support either Hannah's (1973) hypothesis that internals are more responsive to a need for social approval, or Byrne's (1969) similarity hypothesis.     

The time course of automatic lexical access and aging

This study addresses the issue of cognitive slowing in the elderly by examining the time course of automatic lexical access. College-aged subjects typically show a brief rise time (300-500 msec) for lexical access. In the present study, we examine whether there are changes in rapid, automatized access routines with age. Elderly and college-aged subjects performed a lexical decision task wherein semantically related words embedded in a continuous list were presented one at a time with a varying (300-1500 msec) inter-word interval. The use of a continuous list, a repeated word, and a very short inter-stimulus interval allowed automatic lexical access to be straightforwardly examined. The elderly subjects showed an onset of automatic lexical access that was similar in time frame to that for college-age subjects. These findings suggest that wherever the locus of age-related slowing may be, it is not in the early, language-specific processing devices that mediate lexical access.     

Reflections on the process of psychotherapeutic change as applied to medical situations

This article takes the basic ideas on the process of changing implicit knowledge put forward in this special issue, and extends them beyond psychotherapy to include other therapeutic relationships that occur in medicine. One vignette, from an encounter between a medical student and a dying patient, illustrates how a “moment of meeting” changes the student as well as the patient. The second shows how therapeutic interventions for new mothers with their newborn infants involve “moments of meeting” that alter the mother's implicit knowledge of her baby and of herself as a mother. © 1998 Michigan Association for Infant Mental Health