Word valence, attention, and hemispheric activity in depressed, remitted, and nondepressed controls.

Clinically depressed (n = 20), previously depressed (n = 28), and nondepressed control (n = 27) individuals, classified according to a structured clinical diagnostic interview, participated in a study employing a modified prior entry (Titchener, 1908) procedure to investigate interrelationships among word (adjective) valence, visual attention, and cerebral hemispheric activity. Overall, positive words were selected more quickly when presented to the right, versus left, visual field (RVF, LVF); the opposite pattern was observed for negative words. While there was no significant group X Valence X Visual Field interaction, planned comparisons revealed that the aforementioned Valence X Visual Field interaction was significant only for the nondepressed control group. Although the remitted group exhibited an overall pattern similar to the control group, the depressed group evinced a pattern in the opposite direction for positive words (i.e., quicker in the LVF than the RVF).

Sagittal plane analysis of head, neck, and trunk kinematics and electromyographic activity during locomotion.

STUDY DESIGN: Descriptive study examining kinematic and electromyographic (EMG) patterns of the upper body during walking. OBJECTIVE: To examine trunk, neck, and head movements to determine a mechanism for upper body stabilization during walking. BACKGROUND: Dynamic balance of the upper body during walking provides a stable base for function of sensory systems. Prior investigations of upper body motion during walking were limited to examination of isolated segments, or examination of the upper body as a single unit. In our study, the upper body is examined as 3 segments: the trunk, neck, and head. METHODS AND MEASURES: Sagittal plane walking patterns were examined in 8 unimpaired young adults. Markers placed on the trunk, neck, and head segments were recorded on videotape. Angles were calculated with respect to an external horizontal reference to determine segment position relative to space. EMG measures were obtained from erector spinae, rectus abdominus, semispinalis capitis, and sternocleidomastoid muscles. RESULTS: Results showed dynamic stability was accomplished through maintenance of a posture where the trunk was flexed, the neck was extended and the head was flexed. The trunk segment demonstrated greatest stability with the neck being the least stable of the 3 segments. Movements of upper body segments showed a tendency for the head and neck to move opposite to the trunk. EMG data demonstrated erector spinae muscle activity occurring near heel contact of each limb followed by trunk extension. The remaining muscles exhibited variable patterns of activity. CONCLUSIONS: These data indicate that movements of the upper body help to maintain a posture that promotes stability of these segments during walking. The trunk was the most stable of the three segments thereby, providing a stable platform for head and neck movement. Erector spinae muscle activity contributed to upper body movements by extending the trunk to maintain balance at heel contact. These results provide a basis for studying changes in dynamic stability that occur with age.

Horizontal plane head stabilization during locomotor tasks.

Frequency characteristics of head stabilization were examined during locomotor tasks in healthy young adults(N = 8) who performed normal walking and 3 walking tasks designed to produce perturbations primarily in the horizontal plane. In the 3 walking tasks, the arms moved in phase with leg movement, with abnormally large amplitude, and at twice the frequency of leg movement. Head-in-space angular velocity was examined at the predominant frequencies of trunk motion. Head movements in space occurred at low frequencies (< 4.0 Hz) in all conditions and at higher frequencies (> 4.0 Hz) when the arms moved at twice the frequency of the legs. Head stabilization strategies were determined from head-on-trunk with respect to trunk frequency profiles derived from angular velocity data. During natural walking at low frequencies (< 3.0 Hz), head-on-trunk movement was less than trunk movement. At frequencies 3.0 Hz or greater, equal and opposite compensatory movement ensured head stability. When arm swing was altered, compensatory movement guaranteed head stability at all frequencies. Head stabilization was successful for frequencies up to 10.0 Hz during locomotor tasks. Maintaining head stability at high frequencies during voluntary tasks suggests that participants used feedforward mechanisms to coordinate head and trunk movements. Maintenance of head stability during dynamic tasks allows optimal conditions for vestibulo-ocular reflex function.

Head stability in older adults during walking with and without visual input.

The purposes of this study were to 1) characterize head stabilization in older adults across the frequency spectrum of walking, and 2) assess the ability of older adults to adapt head-trunk coordination to maintain head stability in the absence of vision. Sagittal plane head and trunk angular velocities in space were measured for 17 healthy older adults while walking with eyes open (EO) and eyes closed (EC). Average walking velocity and cadence were also determined. Frequency analyses were used to examine head velocities in space and head-on-trunk with respect to trunk gain and phase values across the frequency spectrum of walking. Average walking velocity decreased with EC. Head stability was maintained during EO, but decreased during EC as indicated by increased head velocities across the frequency spectrum. Gain values increased while phase values remained similar during EC walking demonstrating diminished coordination of head-trunk movements. When relying on vestibular and proprioceptive information, older adults were unable to adapt head-trunk movements suggesting impaired plasticity of these systems with age.

Laterality, word valence, and visual attention: a comparison of depressed and non-depressed individuals.

Thirteen depressed and 13 non-depressed college students attended to valence-loaded word pairs (euphoric/dysphoric, euphoric/neutral, and neutral/dysphoric) on a computer screen. Each pair was observed through a viewing box with a vertical partition, each word in a different visual field. As a prior-entry task (Titchener, 1908) the words were simultaneously replaced by colored bars. Participants indicated which color bar (left or right) was seen first. As predicted, identifications of color bars following euphoric words in the right visual field (left hemisphere) exceeded their identification in the left visual field (right hemisphere). Also, as predicted, the non-depressed participants made identifications following the euphoric word of a pair more often than did the depressed participants. No interaction occurred between laterality and participant classification. Implications for research and therapy are discussed.

Reality negotiation in non-depressed and depressed persons.

OBJECTIVES: Non-depressed and depressed persons were hypothesized to input and recall self-referential information that was consistent with their self theories. DESIGN: Non-depressed and depressed persons were compared. METHODS: Non-depressed (14) and depressed (14) students chose between positive or negative audio statements, and then recalled the statements. RESULTS: Non-depressed relative to depressed participants: (i) listened more to the positive than the negative tapes; and (ii) fabricated (i.e. incorrectly recalled) less negative messages. CONCLUSION: Partial support is given to reality negotiation processes.

Mechanisms controlling human head stabilization. II. Head-neck characteristics during random rotations in the vertical plane.

1. In this study we have tested the hypothesis that the mechanisms controlling stabilization of the head-neck motor system can vary with both the frequency and spatial orientation of an externally applied perturbation. Angular velocity of the head with respect to the trunk (neck) and myoelectric activity of two neck muscles (semispinalis capitis and sternocleidomastoid) were recorded in eight seated subjects during pseudorandom rotations of the trunk in the vertical (pitch) plane. Subjects were externally perturbed with a random sum-of-sines stimulus at frequencies ranging from 0.35 to 3.05 Hz. Four instructional sets were presented. Voluntary mechanisms were examined by having the subjects actively stabilize the head in the presence of visual feedback as the body was rotated (VS). Visual feedback was then removed, and the subjects attempted to stabilize the head in the dark as the body was rotated (NV). Reflex mechanisms were examined when subjects performed a mental arithmetic task during body rotations in the dark (MA). Finally, subjects performed a voluntary head tracking task while the body was kept stationary (VT). 2. In VS and NV, gains and phases of head velocity indicated good compensation for the perturbation at frequencies up to 2 Hz. Between 2 and 3 Hz, gains dropped slowly and then steeply descended above 3 Hz as phases became scattered. 3. In MA, gains were lower and exhibited more scatter than in VS and NV at frequencies < 1 Hz. Phases around -180 degrees indicated that compensatory activity was occurring even with these low gains. Between 1 and 2 Hz, response gains steeply ascended, implying that reflex mechanisms were becoming the predominant mechanism for compensation in this frequency range. Above 2 Hz, gains dropped off to 0.5 and lower, but phases remained close to -180 degrees, suggesting that the reflex mechanisms were not dominant in this frequency range, but that they were still contributing toward compensation for the trunk perturbation. 4. Neck muscle electromyographic (EMG) responses were similar in VS, NV, and MA, demonstrating decreasing gains between 0.35 and 1.5 Hz, and then increasing beyond the previous high level of activation. This U-shaped response pattern implies an enhanced participation of neural mechanisms, probably of reflex origin, in the higher frequency range. 5. Patterns observed during external perturbations of the trunk were not apparent in the response dynamics of voluntary head tracking. In VT, subjects successfully tracked the stimulus only at the lowest frequencies of head movement.(ABSTRACT TRUNCATED AT 400 WORDS)

Depressed and normal individuals differ both in selection and in perceived tonal quality of positive-negative messages.

Twenty college undergraduates (10 depressed, 10 nondepressed, in terms of the Beck Depression Inventory and the Structured Clinical Interview for the DSM-III-R) chose freely from a positive or negative tape-recorded message. They also rated the tonal quality of each tape. The nondepressed group selected the positive message more often than the negative message. However, the depressed group showed no difference in tape preference. The nondepressed individuals rated the negative tape as inferior in tonal quality, whereas no difference in tonal quality was reported by the depressed individuals. Results appear to support a response set not only toward positive cognitions among nondepressed individuals, which is absent among depressed individuals, but also toward perceived tonal quality differences.

Priming effects in schizophrenia: associative interference and facilitation as a function of visual context.

Irrelevant stimuli that flank a fixated target may cause either facilitation or interference with target classification. Twenty schizophrenic patients, 20 depressed control patients, and 20 normal control subjects were compared on a flanker priming task that involved the linear display of a target surrounded by two flanking letters or digits. Choice reaction time between letter and digit targets was examined as a function of flanker condition and onset asynchrony between flankers and target. Facilitative priming occurred only with prior exposure of flankers compatible with the response required and was greater in degree with schizophrenic and depressed than with normal subjects. Interference from flankers incompatible with the response required less among schizophrenics than among other groups. Several different processes may be involved in the inhibition of irrelevant information by schizophrenics.

Searching for the phenotypes of schizophrenia.

Use of clinical diagnosis as the phenotype for genetic study is discussed, and criteria for appropriate alternative phenotypes are presented. Then, recent research on four alternatives is discussed: (a) resistance to interference from an associative prime, (b) reaction time crossover, (c) creativity, and (d) socioeconomic achievement. It is concluded that resistance to interference from an associative prime and reaction time crossover at 3-sec. preparatory interval level are the most promising of these candidates.

Visual pattern integration as a function of antidepressant medication in depressed patients.

On the basis of an earlier study that reported depressed patients to be superior to normal control subjects in visual iconic integration, the present investigation sought to determine if this finding was replicable and if medication produced it. Newly admitted depressed patients entering drug treatment, depressed patients already in drug treatment, and healthy control subjects were twice tested, with a 5-week interval between sessions. Fully medicated depressed patients, whether newly admitted or already in drug treatment, were superior to normal control subjects in visual integration, and healthy control subjects were superior to depressed patients just entering treatment. At the first testing, the number of days of medication treatment was significantly correlated with the adequacy of visual integration.

Span of apprehension in schizophrenic patients as a function of distractor masking and laterality.

Twenty schizophrenic patients, 10 depressed control patients, and 20 normal control subjects were compared in a forced-choice, target-detection method for assessing the span of apprehension. The detection task required the subject to report which of 2 target letters was presented among 7 other (distractor) letters. Performance accuracy was examined as a function of target location and whether the distractor letters were masked after their presentation. The backward masking of the distractors improved target-detection accuracy of both control groups but reduced accuracy of the schizophrenic group. In addition, schizophrenics performed particularly poorly on targets located in the left half or lower half of the display. These results suggest that response to the masking of distractors may be a new index of attentional shortcoming in schizophrenia. Various theoretical explanations for the target location findings are also discussed.

Reaction time crossover as a marker of schizophrenia and of higher functioning.

A factor analysis of reaction time crossover data of 53 schizophrenic patients, 45 first-degree relatives, and 38 controls, previously reported by De Amicis and Cromwell, was performed in order to shed light upon the relationship of crossover to aging, mean reaction time, and general socioeconomic functioning. The aging factor shared variance with getting married and having children, but not with reaction time crossover. Crossover was also found to be independent of reaction time speed among first-degree relatives and control subjects; however, it was correlated with reaction time speed among actively symptomatic schizophrenic patients. Additionally, the relationship of crossover to socioeconomic functioning was found to be negative among the patients, positive among the relatives, and nonexistent among control subjects. Results are discussed in terms of previous reports of higher than normal functioning found in relatives of schizophrenic patients.

Clinical and etiological implications of a specific attention deficit in schizophrenia.

Forty-seven psychiatric inpatients, including 26 schizophrenics and 21 nonschizophrenics, were measured on four clinical factors (chronicity, premorbid adjustment, reported symptomatology, and diagnosis) and four indices of reaction time (RT) performance (mean RT, RT variance, and redundancy-associated deficit [RAD] at 3- and 7-second preparatory intervals [PIs] ). Each clinical factor was analyzed in turn as a dependent variable in multiple regression analyses. The RT indices comprised the predictor set in each multiple regression. RAD at 7-second PI is related to chronicity for psychiatric patients in general and for schizophrenic patients in particular. Diagnosis and premorbid adjustment are related primarily to mean RT. No evidence was found that RAD is an artifact of high intertrial variance or long RT latencies, but intertrial variance does play a role in moderating the implications of RAD. The different correlations within schizophrenic and nonschizophrenic groups suggest a) that the Elgin Scale has a different meaning when used with schizophrenics than with nonschizophrenics, and b) that it is not useful to treat schizophrenic and nonschizophrenic disorders on the same continuum. The results in general suggest that the vulnerability factor thought to be associated with RAD militates for greater chronicity across different types of patients. The RAD effect within schizophrenics is nevertheless relatively greater than within other patients.

Magnitude of reaction time crossover in process schizophrenic patients in relation to their first-degree relatives.

The reaction time crossover (redundancy associated deficity) scores of 28 process schizophrenics, selected for the presence of crossover, were correlated with the crossover scores of 53 of their first-degree relatives (one to five relatives for each patient.). The resulting product-moment correlation coefficient was .27 (p < .05), thus lending support to the notion of a familial factor in reaction time crossover.

Schizophrenic/paranoid psychoses: determining diagnostic divisions.

Metadiagnostic guidelines are delineated for evaluating the utility of both existing diagnostic criteria and recently proposed revisions (Magaro 1980). Among the metadiagnostic guidelines are the demonstration of differential treatment-outcome relationships for different disorders and the applicability of the characteristics of a superordinate diagnosis to its subordinate (or subtype) diagnoses. The authors note the conceptual development of the schizophrenia construct. Attempts to verify the existence of subtypes of schizophrenia in psychoanalytic theory, demographic traits, psychological assessment, and behavioral research are reviewed. Data accumulated from these efforts provide evidence regarding the validity of the distinction between paranoid and nonparanoid schizophrenia proposed by Magaro (1980). The authors conclude that a number of alternate relationships between paranoid and nonparanoid subtypes may by hypothesized. Only the notion that paranoid and nonparanoid subtypes are representative of differences in severity of schizophrenia may be rejected. As yet, little evidence exists for choosing one of the remaining alternatives as correct. Integrating research from diverse fields of study is advocated in the effort to refine conceptions of psychiatric disorders. In addition to continued attempts to make improvements in psychiatric diagnosis by changing the clinical symptoms used to define disorders, refinements may be accelerated by assessing the potential utility of other sources of information as the basis for psychiatric diagnosis. Performance on tasks employed in behavioral psychopathology research may represent such an example.

Personal constructs among depressed patients.

The Kelly Role Construct Repertory Test (rep grid) was administered to 19 depressed patients, 19 psychiatric controls, and 19 normal controls. Tests were analyzed to produce measures of cognitive complexity, self-ideal congruency, negative self-construing, identification (self-other distances), and consistency of within-factor self-attribution. In comparison to the two control groups, three characteristics of depressed patients emerged: a) the well known tendency to construe oneself negatively occurred but not in terms of a greater number of factors with consistent negative self-description; instead, b) depressed patients had more mixed (positive and negative) self-description than other patients, thus suggesting a propensity to cognitive slot movement; finally, c) independent of positivity/negativity, depressed patients had a greater tendency to view themselves as different from others. From these findings a formulation about depression is presented, and implications for etiology and treatment are discussed.