Thyroid hormones are associated with cognitive function: moderation by sex, race, and depressive symptoms.

CONTEXT: Recent evidence indicates that thyroid hormones may be closely linked to cognition among adults. OBJECTIVE: We investigated associations between thyroid hormones and cognitive performance, while testing effect modification by sex, race, and elevated depressive symptoms (EDS). DESIGN: This cross-sectional study used extensive data from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study. SETTING: The study was conducted in Baltimore, Maryland, from 2004 to 2009. PARTICIPANTS: PARTICIPANTS were U.S. adults aged 30 to 64 years. The sample size ranged from 1275 to 1346. MAIN OUTCOME MEASURES: Outcomes included 13 cognitive test scores spanning domains of learning/memory, language/verbal, attention, visuo-spatial/visuo-construction, psychomotor speed, executive function, and mental status. RESULTS: Within reference ranges and after Bonferroni correction, elevated free thyroxine (fT4) was associated with better performance on tests of visuo-spatial/visuo-construction ability (overall, women, and African Americans) and learning/memory (women and African Americans), whereas a higher total thyroxine (tT4) level was associated with better performance in the domain of psychomotor speed (individuals without EDS) and higher levels of both fT4 and tT4 were linked to better language/verbal test performance among men. In contrast, higher T3(% uptake) was related to better performance on tests of visuo-spatial/visuo-construction ability and psychomotor speed among whites. When the above reference range was compared within the overall population and after Bonferroni correction, a within reference range fT4 was linked to better performance on visuo-spatial/visuo-constrution ability and psychomotor speed, whereas a below normal range TSH level (compared with the reference range) was linked to better performance in domains of psychomotor speed and attention. CONCLUSIONS: Thyroid hormones and cognition are closely linked differentially by sex, race, and EDS status.

Self-generated happy and sad emotions in low and highly hypnotizable persons during waking and hypnosis: laterality and regional EEG activity differences.

EEG correlates of self-generated happy and sad emotions during counterbalanced conditions of waking and hypnosis were investigated in 16 low ("lows') and 15 highly ("highs') hypnotizable men, as assessed by the Harvard Group Scale of Hypnotic Susceptibility and the Stanford Hypnotic Susceptibility Scale, Form C. Using log mean spectral magnitude, 11 frequency bands (3.5-42 Hz) were evaluated at frontal (F3, F4), central (C3, C4), and parietal (P3, P4) regions. As anticipated, only parietal hemispheric differences in low alpha activity (7.5-9.45 Hz) differentiated between emotions, whereas mid and high alpha activity (9.5-13.45 Hz) did not. There was significantly less low alpha activity in right parietal (P4) in sad than happy emotions, supportive of prior research showing relatively greater right hemispheric involvement in negative than positive emotions. Yet, overall there was more low alpha activity in the left parietal (P3) region. During sadness only in waking, low beta (13.5-15.45 Hz) activity was greater in the right than left frontal region, greater in the left than right central region, and similar in both hemispheres in the parietal region. As anticipated, in comparison to lows, highs showed significantly greater hemispheric asymmetries (right greater than left) in the parietal region in high theta (5.5-7.45 Hz), high alpha (11.5-13.45 Hz), and beta activity between 16.5 and 25 Hz-all frequency bands that are associated with sustained attentional processing. Results support prior research (for reviews, see Crawford, 1994a; Crawford and Gruzelier, 1992) that highs have greater sustained attentional abilities than do lows, which is reflected in different regional brain dynamics. Future EEG research needs to address narrower EEG frequency bands, as well as consider the moderating effects of hypnotic susceptibility level in observed hemispheric asymmetries.

Transient positive and negative experiences accompanying stage hypnosis.

Frequency of positive and negative experiences accompanying stage hypnosis was assessed in follow-up interviews with 22 participants of university-sponsored performances. Most subjects described their experience positively (relaxing, interesting, exciting, satisfying, illuminating, and pleasurable), but some described it negatively (confusing, silly, annoying, and frightening). Five subjects (22.7%) reported partial or complete amnesia; all were highly responsive to the stage hypnosis suggestions. One subject was completely unable to breach amnesia and felt annoyed and frightened. Five subjects (22.7%) believed the hypnotist had control over their behavior. Participants (n = 15) tested subsequently on the Stanford Hypnotic Susceptibility Scale, Form C (Weitzenhoffer & Hilgard, 1962) were mostly moderately to highly hypnotizable (M = 7.07), and the scores correlated significantly (r = .68) with the percentage of passed stage hypnosis suggestions.