Electromyography: A review of the current status of subvocal speech research

Electromyographic studies of subvocal speech are evaluated with two different aims: (1)a methodological review of controls for nonspeech artifact and of data analysis techniques, and (2) a review of substantive findings and suggestions for future research. A highly effective procedure, involving manipulation of phoneme content in certain trials, has been developed to control nonspeech artifact generated by the speech musculature. The commonly used data analysis technique of amplitude measurement of the single highest polygraph pen deflection is inadequate. Techniques which take frequency into account, such as analog computer integration of voltage values, are more sensitive. Even greater sensitivity is needed to isolate individual words so that rehearsal strategies can be investigated. It has been clearly established that preschool children as young as age 4 engage in spontaneous subvocalization that is related to recall in boys but not in girls.     

Text comprehension in aphasia

The semantic and pragmatic strategies in the comprehension of spoken texts are investigated in four subgroups of aphasic patients and in normal and brain-damaged controls. Short texts of similar linguistic structure were read to the subjects, who were required to choose the picture, from a multiple choice set of five, that was appropriate to the story. Besides a picture showing the main event of the story, one picture depicted the literal sense of a metaphorical comment, and the others misrepresented semantic functions expressed in the text. With respect to these types of responses, both aphasics and controls exhibited the same pattern of reaction. It is concluded that the redundancy of texts makes up for the difficulties aphasics have in comprehending isolated words and sentences.     

Conceptual encoding and locus of the Stroop effect

Subjects reacted to coloured season and month names by naming the season associated with the print colour of the word, or by naming the season opposite to the one associated with the print colour. Reactions were facilitated in both tasks when the word on the display named the season associated with the colour or was a month belonging to that season. Opposite season naming was not facilitated when the word named the response which the subject made. A comparable effect of print colour was found when subjects reacted to season names by naming the colour associated with the name, or with its opposite. These results suggest that Stroop congruity and interference effects occur during conceptual encoding, and not during response production.     

A simple technique for correlating film and EMG in locomotion studies

Two recurring problems hampering investigations of muscular activity patterns during locomotion are electrical “noise” and movement artifact in the electromyographic (EMG) signal and proper synchronization of behavioral events to the EMG. A relatively simple technique for achieving these ends is presented. Vigorous locomotor movements of unrestrained animals are recorded on 16-mm film and synchronized with one or more EMGs from selected muscles with little electrical noise or movement artifact interference. The system employs telemetry which is compared to hardwire techniques.     

The effect of alcoholic intoxication upon calorically induced oculogyral illusion

Ten male and 10 female subjects, half of whom were classified as “heavy” and half as “light” drinkers, ingested a 4-1 combination of tonic water and 80-proof vodka in an amount calculated to produce a state of moderate intoxication (average estimated peak blood alcohol level=.075). This resulted in an increased sensitivity (latency, magnitude, and duration) to the calorically induced “oculogyral illusion” (OGI) relative to a placebo (tonic water) condition. “Heavy” and “light” drinkers did not differ significantly on any of the measures. It was speculated that the alcoholic enhancement of the OGI was due either to a decreased ability to suppress vestibular nystagmus when attempting to fixate a visual stimulus or to the expenditure of extra-normal effort in order to maintain fixation.     

Perceptions of personal control and conformity of vocational choice as correlates of vocational development

This study examined differences in vocational maturity of women across different levels of internal-external control and typical versus atypical vocational choice. It was predicted that internally controlled women would have higher vocational maturity scores than externally controlled women; women who make atypical vocational choices would have higher vocational maturity scores than women who make typical choices. Data from the Attitude Scale of Crites' Career Maturity Inventory, MacDonald and Tseng's I-E Scale, and dichotomized ratings of typical versus atypical vocational choice were obtained from 179 freshmen to senior female student volunteers in a large New England university. Analysis of variance indicated that internally controlled women had significantly higher vocational maturity than externally controlled women (p <. 01); no differences were found in vocational maturity between those making typical or atypical vocational choices; the lowest level of vocational maturity was found for externally controlled females making atypical vocational choices. Implications of these findings for counseling are discussed.