Biomedical subjects

Gerianne M Alexander

Publications and source records attributed to Gerianne M Alexander.

11 recordsLinked to original sources

PubMed2006

Associations among gender-linked toy preferences, spatial ability, and digit ratio: evidence from eye-tracking analysis.

Eye-tracking technology was used to monitor eye-movements in 64 adults (age range, 18-22 years) during simultaneous presentation of "masculine" and "feminine" toys. Women and men who showed more visual fixations on male-typical toys compared to female-typical toys had significantly better targeting ability and smaller (i.e., more masculine) digit ratios, a putative marker of prenatal androgen levels. In contrast, individuals with visual preferences for female-typical or male-typical toys did not differ in mental rotations ability and in their retrospective reports of childhood gender-linked activities. The finding that targeting ability and digit ratios varied according to visual preferences for gender-linked toys suggests that prenatal androgens promote enduring preferences for male-typical objects and indicate further that some gender-linked traits vary according to the direction of a visual preference for gender-linked toys. Visual preferences derived from eye-tracking, therefore, may be a useful supplement to current measures of psychosexual differentiation in hormone-behavior research, particularly because eye-movements are not dependent on verbal abilities or subjective evaluations of behavior.

Adult↗

PubMed2005

Perceptual-motor skill learning in Gilles de la Tourette syndrome. Evidence for multiple procedural learning and memory systems.

Procedural learning and memory systems likely comprise several skills that are differentially affected by various illnesses of the central nervous system, suggesting their relative functional independence and reliance on differing neural circuits. Gilles de la Tourette syndrome (GTS) is a movement disorder that involves disturbances in the structure and function of the striatum and related circuitry. Recent studies suggest that patients with GTS are impaired in performance of a probabilistic classification task that putatively involves the acquisition of stimulus-response (S-R)-based habits. Assessing the learning of perceptual-motor skills and probabilistic classification in the same samples of GTS and healthy control subjects may help to determine whether these various forms of procedural (habit) learning rely on the same or differing neuroanatomical substrates and whether those substrates are differentially affected in persons with GTS. Therefore, we assessed perceptual-motor skill learning using the pursuit-rotor and mirror tracing tasks in 50 patients with GTS and 55 control subjects who had previously been compared at learning a task of probabilistic classifications. The GTS subjects did not differ from the control subjects in performance of either the pursuit rotor or mirror-tracing tasks, although they were significantly impaired in the acquisition of a probabilistic classification task. In addition, learning on the perceptual-motor tasks was not correlated with habit learning on the classification task in either the GTS or healthy control subjects. These findings suggest that the differing forms of procedural learning are dissociable both functionally and neuroanatomically. The specific deficits in the probabilistic classification form of habit learning in persons with GTS are likely to be a consequence of disturbances in specific corticostriatal circuits, but not the same circuits that subserve the perceptual-motor form of habit learning.

Adolescent↗

PubMed2004

Habit learning in Tourette syndrome: a translational neuroscience approach to a developmental psychopathology.

BACKGROUND: The etiology of Tourette syndrome (TS) involves disturbances in the structure and function of the basal ganglia. The basal ganglia mediate habit learning. OBJECTIVE: To study habit learning in persons with TS. DESIGN: Patients with TS were compared with normal controls in performance on a probabilistic classification, or habit-learning task (weather prediction). SETTING: University research institute. PARTICIPANTS: One hundred twenty-three children and adults, 56 with a diagnosis of TS and 67 healthy control subjects. MAIN OUTCOME MEASURES: Habit learning was assessed by the extent of improvement in accuracy of predictions and reaction times over trial blocks during performance of the weather prediction task. Declarative learning was assessed by performance on 3 tasks that required intact declarative memory functioning. RESULTS: Children with TS were impaired at habit learning relative to normal controls (P = .01). This finding was replicated in the independent sample of adults with TS (P = .01). The rate of learning correlated inversely with the severity of tic symptoms across both samples (r = -0.34; P = .01). Thus, impaired learning accompanied more severe symptoms. Measures of declarative memory functioning, in contrast, were normal in the TS groups. CONCLUSIONS: Striatal learning systems are uniquely dysfunctional in both children and adults with TS. The correlation of habit learning with symptom severity suggests that the number and severity of tics are a function of the degree to which the system for habit learning is dysfunctional. Thus, both the deficits in habit learning and the tic symptoms of TS are likely to be consequences of the previously reported anatomical and functional disturbances of the striatum in children and adults who have TS. The existence of a well-developed animal model for this learning system, which permits study of the neural and molecular bases of habit learning, has important implications for the neurobiological study of TS and for the development of new or improved therapeutics for this condition.

Attention Deficit Disorder with Hyperactivity↗

PubMed2004

Testing the prenatal hormone hypothesis of tic-related disorders: gender identity and gender role behavior.

The hypothesis that prenatal masculinization of the brain increases risk of tic disorders in postnatal life was tested by measuring gender and gender role behavior in 89 children and adults with a clinical diagnosis of Tourette syndrome or obsessive compulsive disorder and 67 healthy, unaffected children and adults. Consistent with this hypothesis, a tic disorder in females was associated with more gender dysphoria, increased masculine play preferences, and a more typically "masculine" pattern of performance on two sex-typed spatial tasks. Males with tic disorders reported increased masculine play preferences, and the strength of these preferences was positively associated with the severity of tic symptoms. In addition, unlike their female counterparts, males with tic disorders showed a relative impairment in mental rotation ability. These behavioral profiles are consistent with those of children who have verifiable elevations in prenatal androgen levels. These findings therefore support the hypothesis that an altered androgen-dependent process of sexual differentiation during prenatal life may contribute to the development of tic-related disorders.

Adolescent↗

PubMed2003

An evolutionary perspective of sex-typed toy preferences: pink, blue, and the brain.

Large sex differences in children's toy preferences are attributed to gender group identification and social learning. The proposal outlined in this paper is that contemporary conceptual categories of "masculine" or "feminine" toys are also influenced by evolved perceptual categories of male-preferred and female-preferred objects. Research on children exposed prenatally to atypical levels of androgens and research on typically developing infants suggest sex-dimorphic preferences exist for object features, such as movement or color/form. The evolution and neurobiology of mammalian visual processing--and recent findings on sex-dimorphic toy preferences in nonhuman primates--suggest further that an innate bias for processing object movement or color/form may contribute to behaviors with differential adaptive significance for males and females. In this way, preferences for objects such as toys may indicate a biological preparedness for a "masculine" or "feminine" gender role-one that develops more fully as early perceptual preferences are coupled with object experiences imposed by contemporary gender socialization.

Brain↗

PubMed2002

Sex and spatial position effects on object location memory following intentional learning of object identities.

Memory for object location relative both to veridical center (left versus right visual hemispace) and to eccentricity (central versus peripheral objects) was measured in 26 males and 25 females using the Silverman and Eals Location Memory Task. A subset of participants (17 males and 13 females) also completed a measure of implicit learning, the mirror-tracing task. No sex differences were observed in memory for object identities. Further, in both sexes, memory for object locations was better for peripherally located objects than for centrally located objects. In contrast to these similarities in female and male task performance, females but not males showed better recovery of object locations in the right compared to the left visual hemispace. Moreover, memory for object locations in the right hemispace was associated with mirror-tracing performance in women but not in men. Together, these data suggest that the processing of object features and object identification in the left cerebral hemisphere may include processing of spatial information that may contribute to superior object location memory in females relative to males.

Adolescent↗

PubMed2002

Replication of a premenstrual decrease in right-ear advantage on language-related dichotic listening tests of cerebral laterality.

Five fused dichotic word tasks measured perceptual asymmetry in 30 women at 4 weekly intervals. The five tasks varied according to whether the stimuli presented were word-word pairs or nonsense word-pairs, or whether they consisted of neutral words paired with positive emotion-evoking words (e.g. hug-tug), neutral words paired with negative emotion-evoking words (e.g. till-kill), or neutral words paired with neutral words (e.g. bean-dean). Overall right-ear advantage (REA) decreased in the premenstrual week relative to the postmenstrual week, replicating previous results using identical measures. In addition, REA scores were similar at menstrual, postmenstrual and midcycle weeks. Additional data from 12 men suggests sex differences in task performance were small or non-existent. In both women and men, there were no effects of repeated testing on REA, but emotional proclivity indices, defined as the tendency to recall words of positive or negative affective tone, increased across the four test sessions. As found previously, there was a trend for women to hear fewer positive words during the premenstrual week. These data are consistent with other research suggesting that a progesterone-mediated decrease in functional asymmetry occurs in the luteal phase. Future research manipulating task demands (e.g. memory load) or the affective valence of the stimuli may be useful in understanding the observed changes in hemispheric advantage.

Adolescent↗

PubMed2002

An event-related functional MRI study comparing interference effects in the Simon and Stroop tasks.

The Stroop and Simon tasks typify a class of interference effects in which the introduction of task-irrelevant stimulus characteristics robustly slows reaction times. Behavioral studies have not succeeded in determining whether the neural basis for the resolution of these interference effects during successful task performance is similar or different across tasks. Event-related functional magnetic resonance imaging (fMRI) studies were obtained in 10 healthy young adults during performance of the Stroop and Simon tasks. Activation during the Stroop task replicated findings from two earlier fMRI studies. These activations were remarkably similar to those observed during the Simon task, and included anterior cingulate, supplementary motor, visual association, inferior temporal, inferior parietal, inferior frontal, and dorsolateral prefrontal cortices, as well as the caudate nuclei. The time courses of activation were also similar across tasks. Resolution of interference effects in the Simon and Stroop tasks engage similar brain regions, and with a similar time course. Therefore, despite the widely differing stimulus characteristics employed by these tasks, the neural systems that subserve successful task performance are likely to be similar as well.

Adult↗

PubMed2002

Fear of spoiling in at-risk African American mothers.

Mothers actively ascribe intention to the behavior of infants. Mothers also tailor their responses to infant behavior based on conceptions of how each response will influence later behavior. Fears of spoiling an infant may influence a mother's pattern of responsiveness. Sixty-eight at-risk African American mothers completed questionnaires assessing depressive symptoms, self-efficacy, empathy, developmental expectations, and beliefs about spoiling. Mothers with greater concerns about the long-term impact of spoiling reported higher levels of depression, more ways in which infants could be spoiled, and inappropriate developmental expectations when compared to mothers with fewer concerns. The pattern of findings suggests ways that fear of spoiling may influence maternal responsiveness in high-risk groups and potentially lead to disturbed mother-infant relationships.

Adolescent↗

PubMed2002

Sleeping characteristics of children undergoing outpatient elective surgery.

BACKGROUND: A significant number of children undergoing anesthesia and surgery exhibit new-onset sleep-related problems postoperatively. The aim of this longitudinal cohort study was to expand previous research in this area by using a new objective technology. METHODS: This study compared children undergoing general anesthesia and outpatient surgery (n = 92) to a community-based control group of children (n = 77). Data regarding coping, temperament, anxiety, surgical procedures, and postoperative pain were collected. Subjects underwent actigraphy sleep monitoring for at least 3 nights before surgery and 5 postoperative days (POD). Sleep assessment was performed with actigraphy sleep monitoring and the Post Hospitalization Behavioral Questionnaire (PHBQ). RESULTS: Forty-three children (47%) in the surgery group experienced postoperative sleeping disturbances as determined by either the actigraphy or the PHBQ. Only 13 children (14.4%), however, experienced a decrease of at least 1 SD in percentage sleep as assessed by actigraphy. Postoperative pain scores on POD 1 and POD 2 were significantly higher among children who exhibited sleep problems as diagnosed by actigraphy (F = 4.283; P= 0.047). Also, children who exhibited actigraph-based sleep problems scored lower sociability-temperament (14.1 +/- 4.3 vs. 17.5 +/- 3.4; P= 0.04) scores compared with the community group and had a higher rate of change in their perioperative anxiety levels (group x time interaction, F = 5.1; P= 0.03). CONCLUSION: A significant number of children undergoing outpatient surgery experience postoperative sleep-related problems. The clinical significance of this finding, however, is unclear.

Ambulatory Surgical Procedures↗

PubMedDate not supplied

A simple self-report diary for assessing psychosexual function in hypogonadal men.

To examine the performance of a self-report diary to assess psychosexual function in hypogonadal men, 2 groups of eugonadal men and 2 groups of hypogonadal men were asked to record and score parameters for sexual desire, sexual enjoyment, sexual performance, sexual activity, and positive and negative moods daily for 7 days before a clinic visit (data set 1 and 2). The hypogonadal men were also assessed after testosterone replacement and some of the eugonadal men were studied while they were on placebo treatment. In this retrospective analysis, sexual function parameters (sexual desire, performance, and activity score) in the diary discriminated between the hypogonadal and eugonadal men with all measures significantly lower in hypogonadal men (all parameters P <.0001). Significant improvements in sexual desire and performance as well as sexual activity scores (P <.0001 for all parameters) in hypogonadal men after testosterone treatment were readily detected within 30 days. Mood and functional parameters did not show any change over time in eugonadal men on placebo treatment. The mood parameters assessed by the diary showed an excellent correlation with those assessed by the Profile of Mood States. Mood parameters were not clearly different between eugonadal and hypogonadal men at baseline. With testosterone treatment positive mood parameters were significantly increased (P <.0028 and.0001 set in data 1 and 2, respectively), and negative mood parameters improved in hypogonadal men (P <.0003 in data set 2). We conclude that this simple self-report diary is useful in assessing the sexual function and mood profile of hypogonadal subjects in clinical research.

Adult↗