Different areas of skin were shown to have different degrees of compressibility. One skin site was considered more compressible than another if it showed a larger range of indentations resulting from a set range of forces. Two skin sites were found within 5 cm. of each other which demonstrated markedly different compressibilities. Such sites were quite easy to find on the ventral surface of a proximal phalange, and on the dorsum of the hand, but the region of the thenar eminence was much more homogenous with respect to compressibility. / The experimental question asked was how does skin compressibility affect psychophysical functions, while two consistently produced negatively accelerating functions describing tactile sensory intensity? A number of separate psychophysical functions were derived at different skin sites using single pulse mechanical stimuli. At each stimulation site, a subject gave magnitude estimates for a set of controlled skin indentations and for a set of controlled forces. / Out of four subjects tested, two consistently produced positively accelerating psychophysical functions, while two consistently produced negatively accelerating functions. It was predicted that if psychophysical functions based on force were affected by skin compressibility, a more compressible skin site would provide for a larger exponent. This prediction was observed in eight out of twelve cases (three skin regions on each of four subjects). Out of the eight predicted exponent changes, four were statistically significant using a regression analysis of variance. None of the four exponent changes which were counter to the prediction were statistically significant. / It was also predicted that if psychophysical functions based on skin indentation were affected by skin compressibility, a more compressible skin site would provide for a smaller exponent. This prediction was observed in eleven out of twelve cases. Out of the eleven predicted cases, five were statistically significant exponent differences. Many of the statistically insignificant exponent changes could be attributed to comparing two stimulation sites which did not have very different compressibilities. / It was apparent that skin compressibility does play a role in determining how intense a given mechanical stimulus feels. It was hypothesized that, regardless of the stimulus dimension, the difference in skin compressibility may cause a difference in the effective area of the stimulus, or the surface gradient produced by the stimulus, or both. A difference in the effective area would translate into a difference in the number of mechanoreceptors recruited. A difference in the surface gradient may cause a difference in the response of some mechanoreceptors. / An examination of the variability of the magnitude estimates indicated two things. (1) A power function model of the stimulus intensity - tactile sensory intensity relationship is better than a straight linear model. (2) A given skin indentation at a constant rate of indentation is a less ambiguous signal of intensity than a given force at a constant rate of force change. / Source: Dissertation Abstracts International, Volume: 41-03, Section: B, page: 1140. / Thesis (Ph.D.)--The Florida State University, 1980.

The purpose of this study was to identify personality characteristics that interact with challenging situations to produce increases in cardiovascular responding. Eighty four subjects were pretested with the Jenkins Activity Survey and the State-Trait Anger Expression Inventory to identify individuals with the Type A or Type B behavior pattern and who additionally could be classified with high levels of hostility expressed, hostility experienced but suppressed, and hostility controlled. While monitoring subjects physiological functioning (blood pressure and heart rate), each individual engaged in a pursuit rotor task in an attempt to "beat" fictitiously presented times. An analysis of covariance between resting measures and challenge period measures identified greater mean blood pressure increases for Type As over Type Bs. No main effects for hostility type were found. When the analysis focused on sex differences, the Male Type A group had significant increases in blood pressure over Type B males and both female A/B groups. Additionally, significant blood pressure differences were evident between the male Hostility-Out and female Hostility-Out groups (independent of the Type A/B categorization). The results suggest that personality characteristics previously associated with cardiovascular reactivity may be more of a risk factor for males than females. / Source: Dissertation Abstracts International, Volume: 51-06, Section: B, page: 3154. / Major Professor: E. I. Megargee. / Thesis (Ph.D.)--The Florida State University, 1990.

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This study examined the effects of the Type A behavior pattern on cardiovascular arousal and cognitive appraisal in 60 elementary school boys engaged in a competitive interaction. Type A and non-Type A boys were randomly assigned to one of three treatment conditions to examine how competitor characteristics interact with Type A tendencies: (a) hostile, competitive opponent, (b) pleasant, competitive opponent, or (c) noncompetitive peer. Cardiovascular arousal (systolic blood pressure, diastolic blood pressure, and heart rate) was assessed at baseline, after a videotaped competitive inducement by the opponent, and during play on a video game. The subject's cognitive appraisal of himself and the opponent was examined. Subject and parent ratings of hostility were obtained. No differences were found between Type A and non-Type A boys on cardiovascular arousal, cognitive appraisal, or parent or self-rated hostility. Subjects exposed to a hostile or a pleasant competitor demonstrated significantly greater systolic blood pressure during competition than those exposed to a noncompetitive peer. There were no significant differences between treatment conditions for diastolic blood pressure or heart rate. The predicted interaction between subject Type A tendencies and competitor characteristics did not occur. The failure to produce significant Type A/non-Type A differences on cardiovascular and cognitive appraisal indices was attributed to subject selection procedures excluding boys with Attention Deficit Hyperactivity Disorder characteristics. / Source: Dissertation Abstracts International, Volume: 52-04, Section: B, page: 2287. / Major Professor: Jack G. May, Jr. / Thesis (Ph.D.)--The Florida State University, 1991.

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An experiment was conducted to examine how eye movements during reading of regular and phrase-segmented texts vary with reading performance. Each participant read a set of either regularly formatted or phrase-segmented texts as eye movements were monitored. Each text was followed by a set of comprehension questions. The effects of individual differences (high- vs. low-performance readers) and text formatting (regular vs. phrase-segmented) were investigated by examination of readers' eye movement patterns. Previous research has revealed that poor readers' performance on tasks that require syntactic processing differs from that of good readers', and that poor readers' comprehension and reading rate improves when presented with phrase-segmented text. It was hypothesized that high- and low-performance readers' eye movements would differ during regular text reading in replication of previous research, and that furthermore low-performance readers' eye movements while reading phrase-segmented text would resemble those of high-performance readers' in the same condition. Results revealed differences between high- and low-performance readers' eye movements for regular texts, but not for phrase-segmented texts. This was due to changes in eye movement measures across text conditions for low-performance readers only.

Recent theories propose that subtle emotional feelings can guide decision-making when insufficient information about the source of those feelings exists. To assess whether emotion experiences possess the properties necessary to play this functional role, subjects in the present study reported on feelings elicited by visually masked emotional pictures. Potential sources of individual differences in the ability to discriminate subtle "gut feelings" were also explored. 16 long-term meditators and 18 non-meditators viewed a series of pictures with pleasant, neutral, and unpleasant content, both masked and nonmasked, and reported on experienced valence and arousal, while measures of skin conductance (SCR), facial electromyography (EMG), and heart rate (HR) were simultaneously recorded. Masked emotional pictures did not elicit discriminatory SCR or EMG responses. HR discriminated among masked pictures by arousal, but not by valence. Both meditators and controls discriminated among masked stimuli in self-reported arousal, but only non-meditators demonstrated accurate valence discrimination. Unpleasant pictures were better discriminated from neutral pictures than were pleasant pictures. Ability to detect feelings elicited by masked stimuli was unrelated to heartbeat detection ability, cardiac vagal tone, or self-reported attention to emotional states, though self-reported emotional clarity predicted better arousal discrimination. It is proposed that awareness of emotion experience may involve both a visceral awareness and a non-visceral awareness of feeling qualities. Long-term meditation practice of the type adopted by participants in the present study, with its focus on the former, may reduce access to non-visceral feeling states.

The experiments that makeup this dissertation are designed to test the theory that the hippocampus functions as a path integrator of optic, vestibular, and ambulatory self-motion information. Hippocampal neural recordings were made in eight subjects during manipulation of the self-motion cues. In the first experiment, rats were trained to drive a car between physical locations on a circular track, thereby eliminating ambulatory self-motion signals. This manipulation resulted in a multitude of changes in hippocampal neural activity. The spatial information content and firing rate of CA 1 pyramidal cells, the power of the hippocampal theta rhythm with its first harmonic, and the modulation of single-unit firing by the theta rhythm were significantly reduced, but not entirely eliminated, when ambulatory cues were eliminated. The amplitude of one of the two hypothesized current generators of the rhythm is shown to be dependent on the ambulatory velocity of the animal. Higher velocities were associated with more prominent "shoulders" in the theta wave. During driving, the theta wave was similar in shape and amplitude to the theta wave obtained during low (near 0)-velocity walking. The results indicate that distance information from locomotor activity is represented in the hippocampal theta rhythm and the firing rates of CAI pyramidal cells. In the second experiment, the entire maze was rotated around the animal during driving, a condition simulating movement optically when the animal was, in fact, stationary. Under these conditions, place specificity and firing rate were further reduced compared to the car driving condition. The theta rhythm that remained after the elimination of ambulatory cues was not affected by the additional elimination of vestibular self-motion cues. Overall, the data suggest that directional information from the vestibular system and distance information from ambulation are integrated in the hippocampal ensemble code for space. Thus, the results are consistent with a role of the hippocampus in path integration.

Recent investigations have shown little evidence of differential improvement of written disclosure for bereaved individuals over a control condition. The present study hypothesized that a moderator may interact with disclosure. Vagal tone, as indexed by respiratory sinus arrhythmia (RSA), was proposed to moderate the effect of written disclosure. Vagal tone has been shown as an individual difference in self-regulation in the infant literature, and more recently in adults with depression, anxiety, and daily stressors. The present study investigated thirty-five bereaved participants in a longitudinal design, with participants writing each week for three weeks, a one-week and one-month follow-up. As with previous studies, bereaved participants showed improvement over the two-month period, although no differential improvement was seen in the emotional disclosure group. As hypothesized, however, those participants with the highest RSA benefited most from the written disclosure, while RSA level did not predict outcome for those in the control condition. Future research should investigate if this moderator effect may be present in written disclosure for non-bereaved individuals.

The main purpose of this study was to investigate whether emotion processing deficits previously reported in individuals with Alzheimer's disease (AD) represent a direct extension of their cognitive impairments or a specific emotion processing deficit, and whether affective information is available, but inaccessible to consciousness in AD. Another aim was to determine whether AD patients have the same emotional experiences to affective stimuli as do other healthy, but non-demented older individuals. An autonomic recognition paradigm was developed to compare overt (verbal report) and covert (electrodermal) facial affect recognition in 19 mildly to moderately demented AD patients and in 19 age- and education-matched cognitively-intact controls (NCs). Subjective reactions and physiological responses to emotionally-laden materials were also compared within and across groups. Contrary to expectation, the two groups did not significantly differ in their ability to correctly match an emotion name with an affective facial expression. As expected, both groups generated significantly more frequent event-related skin conductance responses (ER-SCRs) to congruent, as opposed to incongruent emotion name/facial expression stimulus pairs, and evidenced similar levels of electrodermal activity while viewing images which differed in emotional valence. There were no significant group differences in subjective reactions to emotional pictures; both AD patients and NCs rated positive, negative, and neutral slide images similarly across the dimensions of valence and arousal. AD patients did, however, have more difficulty discriminating facial identity and facial affect than did NCs. There was some indication that these relative impairments may have been related to the dual-task demands inherent in the tests employed. Performances on emotion processing tests used in this experiment did not significantly correlate with measures of orientation/mental status, dementia severity, or depression in either group. Taken together, the results of this study suggest that the difficulties AD patients have on emotion processing tasks are primarily related to specific cognitive demands of the tests employed and do not reflect a specific disruption in emotion processing systems.