Speech disturbances and gaze behavior during public speaking in subtypes of social phobia

Twenty-four social phobics with public speaking anxiety and 25 nonphobic individuals (controls) gave a speech in front of two people. Subjective anxiety, gaze behavior, and speech disturbances were assessed. Based on subjects' fear ratings of social situations, phobics and controls were divided into the generalized and nongeneralized subtype. Results showed that generalized phobics reported the most, and nongeneralized controls the least anxiety during public speaking. All subjects had longer and more frequent eye contact when delivering a speech than when talking with an experimenter or sitting in front of an audience. Phobics showed more filled pauses, had longer silent pauses, paused more frequently, and spent more time pausing than controls when giving a speech. Generalized phobics spent more time pausing during their speech than the other subgroups (nongeneralized controls, generalized controls, and nongeneralized phobics). These results suggest that generalized phobics tended to shift attentional resources from speech production to other cognitive tasks.

Acute and delayed effects of alprazolam on flight phobics during exposure

In order to test if a benzodiazepine would enhance or hinder the therapeutic effects of exposure, immediate and delayed effects of alprazolam on flight phobics were assessed by questionnaires and ambulatory physiological recording. Physiological measures included heart rate, skin conductance level and fluctuations, finger temperature, respiratory sinus arrhythmia, and various respiratory measures derived from two bands calibrated for each subject. Twenty-eight women with flying phobia flew twice at a 1-week interval. One and a half hours before flight 1, 14 randomly assigned phobics received double-blind 1 mg of alprazolam and 14 received placebo. On flight 1, alprazolam reduced self-reported anxiety (5.0 vs 7.4) and symptoms (5.3 vs 3.6) more than placebo, but induced an increase in heart rate (114 vs 105 bpm) and respiratory rate (22.7 vs 18.3 breaths/min). Before flight 2, the alprazolam group did not expect to be more anxious than the placebo group (6.7 vs 6.5), but in fact indicated more anxiety during flight (8.5 vs 5.6), and a substantial increase in panic attacks from flight 1 to flight 2 (7% vs 71%). Heart rates in the alprazolam group increased further (123 bpm). Results indicate that alprazolam increases physiological activation under acute stress conditions and hinders therapeutic effects of exposure in flying phobia.

Clinical characteristics of flight phobia

Sixty-six subjects with severe fear of flying were recruited by advertisement and compared to 21 controls without flying fears. Subjects were interviewed and given several questionnaires to determine DSM-III-R diagnoses, history of flying, and development and course of flying phobia. Our phobic sample had a mean age of 46 and was 89% female. Diagnostically, 27% met criteria for current Panic Disorder with Agoraphobia, and 17% criteria for that diagnosis in the past. These two groups were more concerned with internal or social anxiety stimuli during flight than the group who had never had panic attacks but met criteria for Simple Phobia (flying). All three groups were equally concerned about external dangers. Traumatic flight events were common in phobics and controls, but phobics reported reacting to these events more strongly. Our results suggest a vulnerability-stress model with several vulnerability factors, including cognitive ones. Treatment implications are discussed.

Automatic and effortful processing in aging and dementia: event-related brain potentials

Automatic and effortful processes were investigated using event-related brain potentials (ERPs) recorded from moderately impaired subjects with probable Alzheimer's Disease (AD), normal elderly, and normal young controls. The effects of effortful attention on ERPs to loud noises and the effects of stimulus intrusiveness on effortfully elicited ERPs were studied. First, ERPs to task relevant and irrelevant startling noises were compared. Second, ERPs to startling noises and moderate tones were compared when both were targets. The effects of age (young vs. elderly controls) and effects of dementing disease (AD subjects vs. elderly controls) were also assessed. Effortful attention augmented noise-elicited P300 amplitude in elderly subjects, but not in young. Intrusiveness augmented task-relevant P300 amplitude in young subjects, but not in elderly. Neither variable affected P300 amplitude in AD subjects. Thus, effects of age and disease depended on how P300 was elicited: when effortfully elicited, P300 amplitude was affected by disease but not age; when automatically elicited, P300 amplitude was affected by age but not disease. N1 effects differed from P300 effects.

N400 evidence of abnormal responses to speech in Alzheimer's disease

The status of semantic priming in Alzheimer's disease (AD) was examined using the speech elicited N400 component of the event-related brain potential (ERP). Speech was naturally paced, with 1 s of silence before the final word. In the semantic task, subjects attended to the meaning of the sentences for a subsequent memory test. In the phonemic monitoring task, they counted the words beginning with the letter 'p'. The effects of age were assessed by comparing young and elderly, and the effects of disease by comparing elderly and AD subjects. In healthy young and elderly subjects, N400s were large to semantically unprimed words and small to semantically primed words. In AD subjects, N400s were large to primed words, reflecting a failure of the sentence stem to prime the final word, and probably an impairment in semantic knowledge. The N400 priming effect was not smaller during the phonemic than semantic task in any group, suggesting that the semantic qualities of speech are processed even when subjects are attending to phonemic qualities. N400 latency was delayed with age and further delayed with dementia.

Activation in novice and expert parachutists while jumping

Heart and respiration rates were measured ambulatorily in 16 novice and 25 expert (> 380 delayed free-fall jumps) sports parachutists while making a static-line jump. Self-reported anxiety and heart rate peaked near the point of jumping in both groups rather than earlier in experts, as reported by Fenz and Epstein (1967, Psychosomatic Medicine, 29, 33-51). While sitting in the airplane 1 min before exit, mean heart rate was 124 bpm in novices and 102 in experts and increased during jumping to 170 and 145, respectively. The almost identical rise in the two groups could be accounted for largely by physical exertion, replicated with jumps from a training model on the ground. Exercise testing at a different location showed that experts were more fit. Respiration rate was higher in the airplane than at baselines, especially for novices. In conclusion, our results are more compatible theoretically with extinction of anticipatory anxiety than with learned anxiety inhibition.

Conditioning theory: a model for the etiology of public speaking anxiety?

To study the etiology of public speaking anxiety (speech phobia), 30 Ss with the fear of public speaking, and 24 controls without this fear were asked about past public speaking experiences, their beliefs about the main reason for their phobia, and their concerns in the feared situation. All speech phobics met the DSM-III-R criteria for social phobia. Results showed that traumatic external events, vicarious and informational learning--the causes for phobia that fit in best with Rachman's conditioning theory--were notably uncommon among these phobics, who attributed their fear most often to panic attacks. Yet it was not clear whether panic attacks were causes or consequences of phobia.

Psychophysiological differences between subgroups of social phobia

Individuals meeting criteria of the revised third edition of Diagnostic and Statistical Manual for Mental Disorders (American Psychiatric Association, 1987) for social phobia with a fear of speaking in front of people were subdivided into those with (n = 16) and without (n = 14) avoidant personality disorder (APD). These individuals and nonanxious controls (n = 22) spoke in front of a small audience while speaking time, subjective anxiety, fearful thoughts, and electrocardiographic and respiratory measures were recorded. Controls spoke for longer than either social phobia group. Those with social phobia and APD reported more subjective anxiety and more fear cognitions than the other two groups; phobic individuals without APD showed greater heart rates in the phobic situation than either social phobics with APD or controls. The latter two groups did not differ in heart rate. These results indicate incongruent subjective and heart rate responses to the feared situation. A similar pattern of results was found when participants were divided into generalized and specific social phobia groups.

Elderly men and women are less responsive to startling noises: N1, P3 and blink evidence

Previously we observed that the P3 component of the event-related brain potential (ERP) elicited by startling noises, and to a lesser extent P3 to target tones, is reduced in the elderly (Ford & Pfefferbaum, 1991). In the current experiment, we tried to eliminate possible effects of age-related hearing deficits on the responses to noises by filtering them to include only frequencies heard best by the elderly (0-1000 Hz) and by setting noise intensity relative to each subject's threshold (sensation level, SL). Twelve younger (mean 22 years) and 12 older (mean 69 years) men and women listened to three sequences of tones (80%, 500 Hz, 70 dB SPL) and noises (20%). One type of noise occurred in each sequence (wide band noise set to 107 dB SPL, narrow band noise set to 107 dB SPL, or narrow band noise set to approximately 65 dB SL). The order of the three sequences was counterbalanced across age and sex. Younger subjects blinked to the noise 4-5 times more often than older subjects and had N1 and P3 amplitudes that were 2-3 times larger, regardless of the noise type. N1 amplitude to the background frequent tones and non-startle blinks did not differ between groups. Thus, even when noises were narrow band and set relative to each subject's threshold, older subjects were less responsive to startling auditory stimuli than were younger.

ERPs for infrequent omissions and inclusions of stimulus elements

A negative event-related potential (ERP) wave called mismatch negativity (MMN) is elicited by an infrequent deviant stimulus in a sequence of frequent standard stimuli. Omission of a stimulus in a sequence of stimuli, however, has been considered to elicit a negativity different from MMN. The present study addressed this issue by examining ERPs for infrequent omissions and inclusions of compound stimuli or their elements. Three kinds of stimuli were presented: a 1000-Hz sine wave tone (Sine), white noise with the 1000-Hz frequency sharply filtered out (Noise), and a composite of the pure tone and the filtered white noise (SiNoise). All stimuli had 50 ms duration and were presented with a regular interstimulus interval of 650 ms. Intensities were 75 dB SPL for the tone and noise stimuli and slightly higher for the composite stimulus. The three kinds of stimuli were presented on separate runs, either as the frequent stimulus or one of two infrequent stimuli, each with 10% probability. Infrequent omission of the large stimulus element (Sine deviant to SiNoise) tended to elicit later MMN than inclusion of the same element (SiNoise deviant to Sine). Omission of the small stimulus element (Noise deviant to SiNoise) elicited a smaller and later MMN than did inclusion of the same element (SiNoise deviant to Noise). These data suggest that MMNs are also elicited by partial stimulus omissions, although they seem to be more sensitive to other kinds of stimulus deviances.

ERPs in schizophrenia: effects of antipsychotic medication

Thirty unmedicated schizophrenics were compared to 29 age-matched controls on auditory and visual event-related brain potential (ERP) paradigms. Twenty-one of these patients were tested again after 1 week on placebo and after 4 weeks on antipsychotic medication. Before treatment, N1, N2, and P3 components of the auditory ERP were smaller in the schizophrenics than in the controls. Although visual N2 was smaller in schizophrenics, visual P3 was not. In spite of significant clinical improvement with antipsychotic treatment, amplitudes of auditory and visual N1, N2, and P3 were not significantly changed. Higher blood levels of antipsychotic medication were related to reductions in auditory P3 latency, however. In addition, higher levels of cerebrospinal fluid (CSF) MHPG (methoxyhydroxyphenylglycol) were associated with larger auditory N1s and larger auditory and visual P3s, suggesting an influence of arousal on these components in schizophrenics. In spite of this influence, reduction of the auditory P3 in schizophrenia is an enduring trait of the disease, which is not affected by antipsychotic medication or clinical improvement.

Stress test reactivity in panic disorder

The psychological and physiological reactivity of 52 patients with panic disorder to mental arithmetic, cold pressor, and 5% carbon dioxide inhalation tests was compared with that of 26 age- and sex-matched normal subjects. In general, patients with panic disorder were neither more physiologically reactive to these stressors than normal subjects nor slower to recover from them, but they were tonically more anxious and much more likely to ask to stop carbon dioxide inhalation or to report panic attacks during this test. Patients who reported panic attacks (46%) had manifested greater anticipatory anxiety before the gas was delivered, accompanied with increased beta-adrenergic cardiac tone. Thus, anticipatory anxiety can be an important factor in panic provocation. Physiological measures varied greatly in their sensitivity to phasic or tonic anxiety. Carbon dioxide stimulated large increases in respiratory minute volume, but these increases were no greater for patients than for normal subjects.

Guidelines for reducing the risk of disease transmission in the psychophysiology laboratory. SPR Ad Hoc Committee on the Prevention of Disease Transmission

The acquired immunodeficiency syndrome (AIDS) pandemic has highlighted the need for safeguards against the inadvertent transmission of infectious disease in the psychophysiology laboratory. These Guidelines identify factors contributing to the risk of bloodborne disease transmission to subjects or technicians, and recommend procedures to minimize such risk, given current knowledge and techniques. The lowest risk is associated with the application of devices, such as surface electrodes, to nonabraded, intact skin. Such devices should be clean, but do not require disinfection. The potential risk of infection is higher when surface electrodes are applied to non-intact skin. Abrasion, or other breaks in the skin, can allow seepage of blood products carrying such pathogens as hepatitis B virus and the human immunodeficiency virus that causes AIDS. Thus electrodes require high-level disinfection before reuse on non-intact skin. In addition, technicians should wear gloves during skin preparation and should abrade the skin no more than necessary, using only sterile, preferably non-sharp materials. The highest risk is that associated with items that enter sterile tissue, such as subdermal electrodes and the needles and lancets sometimes used in skin preparation. Such items must be sterile at the time of use and must be handled with extreme caution.

Imipramine and alprazolam effects on stress test reactivity in panic disorder

The reactivity of 40 panic disorder patients on mental arithmetic, cold pressor, and 5% CO2 inhalation stressors was tested before and after 8 weeks of treatment with imipramine, alprazolam, or placebo. Mean levels of subjective and physiological stress measures were compared during a baseline before any stressors were given, and at anticipation, stressor, and recovery periods for each stressor. After treatment, imipramine patients differed from the other two treatment groups on the prestressor baseline in showing higher systolic blood pressure (mean difference about 10 mmHg), higher diastolic blood pressure (10 mm Hg), higher heart rate (15 bpm), less respiratory sinus arrhythmia, shorter pulse transit time, and lower T-wave amplitude. Respiratory measures, electrodermal measures, body movement, and self-reported anxiety and excitement did not distinguish the groups. Reactivity to the stress tests was unaffected by the medications, but tonic differences present in the baseline persisted.

Auditory event-related potentials and electrodermal activity in medicated and unmedicated schizophrenics

Event-related potentials (ERPs) and electrodermal activity were studied in 14 medicated schizophrenics, 17 unmedicated schizophrenics, and 23 age- and education-matched controls. Subjects were run in three auditory stimulus paradigms differing from the usual ERP paradigms in having interstimulus intervals greater than 12 sec to permit measurement of the longer latency skin conductance response (SCR). In every paradigm medicated but not unmedicated schizophrenics had smaller N120 amplitudes and fewer SCRs than controls. In addition, medicated schizophrenics showed reduced P200 amplitude and latency, longer P320 latency, and reduced skin conductance levels in certain paradigms. These effects cannot easily be attributed to different mental states of medicated and unmedicated patients, since their Brief Psychiatric Rating Scale scores were almost the same. It is more probable that antipsychotic and antiparkinsonian drugs reduced electrodermal activity through anticholinergic mechanisms and that the antipsychotic drugs attenuated N120 through other biological mechanisms.

Effect of two beta-blockers on stress during mental arithmetic

Heart rate, blood pressure, and subjective stress ratings were recorded from 36 healthy normotensive students at three points in time: during a drug-free baseline, during a baseline 2 h after ingesting single oral doses of atenolol (75 mg), metoprolol (150 mg), or lactate placebo, and during a subsequently administered mental arithmetic test. Both beta-blockers equally reduced baseline heart rate and heart rate response to arithmetic, but subjective stress rating increases to arithmetic were greater for atenolol than for placebo and metoprolol. These results are contrary to peripheral theories of anxiety regulation. While the hydrophilic atenolol barely penetrates the blood-brain barrier, the lipophilic metoprolol can exert direct CNS effects in addition to its peripheral actions. Central stress-dampening effects of lipophilic beta-blockers may override peripheral baroreceptor-mediated stress-promoting effects.

Skin conductance habituation in panic disorder patients

Skin conductance habituation was compared between 38 patients meeting DSM-III criteria for Panic Disorder and 29 normal controls. Approximately half of each group was randomly assigned to be given 100 dB SPL tones and the other half 75 dB tones. All indices pointed to slowed habituation in patients compared with normals: number of trials to response habituation, total number of responses, and slope of decline of skin conductance level. Patient-normal differences were not significantly larger for 100 dB than for 75 dB. In addition, patients compared with normals had more nonspecific fluctuations, higher skin conductance levels, and a shorter response latency to the first stimulus. Stepwise discriminant analyses classified patients and normals better in the 100 dB than in the 75 dB condition, and showed that the various skin conductancy variables were largely redundant at the higher intensity.

Effects of stimulus repetition, duration, and rise time on startle blink and automatically elicited P300

Intense auditory stimuli of sudden onset evoke not only startle blinks but also an event-related potential component resembling classic P300, even when subjects have no assigned task. To more closely examine the relationship of this P300 to startle, event-related potentials and eyeblink were recorded from 16 young adults in three paradigms designed to produce wide variation in startle amplitude: an Habituation series of 30-ms, 105dBA white noise bursts, a Duration paradigm which presented 105dB noise bursts for 3, 10, 30, or 90 ms, and a Rise Time paradigm which varied the rise/fall times (3, 15, 30, and 45 ms) of 110dBA, 1000-Hz tone bursts. Subjects received two runs of each paradigm. Only on the final Duration and Rise Time runs were stimuli explicitly task relevant; on those runs subjects rated verbally, midway in each 8.4-s interstimulus interval, the disturbingness of the prior sound. Although even the briefest noise bursts evoked parietal P300 as well as startle blink, P300 did not behave like startle. P300 habituated more slowly than did blink amplitude, was more responsive to sustained noise than were blink, N110, and P190, and most importantly, did not show the sensitivity to stimulus rise time manifested by these measures. These findings suggest that the amplitude of automatically elicited P300 is not governed by the same mechanisms as startle amplitude, but behaves more like a defense response.

Motor activity and tonic heart rate in panic disorder

Motor activity and tonic heart rate were monitored in 62 drug-free panic disorder patients and 40 normal control subjects. Mean daily activity, mean waking heart rate controlled for activity, and mean sleeping heart rate were determined. Panic disorder patients without phobic avoidance showed higher activity than control subjects or patients with limited or extensive avoidance. Similarly, an "inverted U", relationship between trait anxiety and activity was observed. On the other hand, neither mean waking nor sleeping heart rate showed significant differences between patients and controls, suggesting that the differences previously reported in laboratory studies result from anticipatory anxiety.

Surreptitious drug use by patients in a panic disorder study

In a double-blind, placebo-controlled trial comparing alprazolam and imipramine for panic disorder, serum analysis revealed that a substantial proportion of the patients took explicitly prohibited anxiolytic medication. Excluding these patients changed the results.