Group relationships and homomorphisms of Boolean matrix semigroups

The image matrix obtained from a blocked Boolean matrix gives a homomorphism provided that the product of any two nonzero blocks is nonzero. All maximal nonzero Boolean matrix semigroups are found. Those invariant under conjugations by a permutation matrix have the form G_i = {A: the sum of any ith rows of A (or all rows) has at least i ones (or all ones)}.     

Multiple component agraphia in a patient with atypical cerebral dominance: an error analysis

A 52-year-old man with atypical cerebral dominance (left-handed for writing but mixed handedness for other tasks) suffered an extensive right hemisphere stroke, resulting in a combination of deficits that has not been previously reported. There were profound visual constructive and visual perceptual disturbances and a spatial agraphia, which were consistent with a nondominant hemisphere lesion. There was also a severe apraxic agraphia, which is typically associated with a dominant hemisphere lesion, but no other signs of dominant hemisphere dysfunction such as linguistic disturbance or limb-motor apraxia were present. This case serves to highlight the functional and anatomical relationship between handwriting and other forms of praxis; the various sources of error in letter formation; the need to be specific in labeling and describing agraphias ; and the role of a detailed analysis of writing errors in delineating the neuropsychological processes involved in handwriting.     

Stuttering and anxiety: The difference between stutterers and nonstutterers in verbal apprehension and physiologic arousal during the anticipation of speech and non-speech tasks

To test if stressful anticipation of speech situations is a factor in eliciting stuttering behavior, the difference between 24 stutterers and 24 nonstutterers in verbal apprehension and physiologic activity was studied before and during speech tasks (reading and conversation), and nonspeech tasks (motor and intelligence task).Results indicate that the difference between stutterers and nonstutterers mainly were restricted to anxiety ratings assessed after each task. Heart rate, vasomotor responses, and electrodermal activity recorded before and during speech tasks were higher compared with the physiologic activity before and during nonspeech tasks but, unexpectedly, this was also the case for nonstutterers. It is concluded that stuttering is not elicited by anxiety.     

The effect of semantic plausibility on sentence comprehension in aphasia

Tested were 50 aphasic patients (16 Broca's, 15 Wernicke's, 10 global, and 9 amnesic), 13 nonaphasic brain damaged patients, and 13 normal adults to evaluate the effect of semantic plausibility on sentence comprehension in active affirmative declarative sentences with a sentence-picture matching task. A plate of two pictures was provided for each stimulus sentence, and the subject was required to choose the picture corresponding to the sentence presented auditorily. Two types of sentences in terms of plausibility were prepared, i.e., probable sentences (P) describing common events in our daily life and improbable sentences (I) describing rare events. There were four kinds of combinations of a picture with the other to make a correct/(distractor) set, i.e., P/(P), P/(I), I/(P), and I/(I) constructions. The results indicated that probable sentences were more comprehensible than improbable sentences, and that the effect of semantic plausibility did not differ among aphasic types.     

Prognostic factors and classification issues in the treatment of secondary orgasmic dysfunction

The present study examined patient and problem characteristics as well as therapy process factors associated with success and failure in sex therapy for secondary orgasmic dysfunction. Ss were 23 married couples selected for emotional and marital stability; all wives were suffering from secondary orgasmic dysfunction. Sexual functioning and satisfaction were evaluated before and after 15 sessions of therapy. Ss also engaged in daily self-monitoring throughout the therapy program. Two criteria of therapeutic success were used: the couples' global sexual harmony and the females' frequency of orgasmic response in couple sexual activity. Higher pre-treatment masturbation rates by the female, as well as better awareness of her partner's sexual tastes and preferences, were related to poor therapeutic outcome. Greater pre-treatment enjoyment of non-genital caressing by the female as well as higher incidence of interpersonal orgasmic response in the past were associated with therapeutic success. The theoretical and research implications of the present findings are discussed.     

Social skills training and systematic desensitization in reducing dating anxiety.

Cooper et al. (1969) have criticized the types of target behavior chosen for therapy analogue studies for being irrelevant to clinical practice. A potential target behavior which appears to be pervasive, complex and directly relevant to clinical practice is interpersonal anxiety. Of special concern to college students is the interpersonal anxiety elicited by members of the opposite sex. especially in dating situations (Martinson and Zerface, 1970).An individual may experience interpersonal anxiety because of a deficit in social skills (reactive anxiety) or because of prior conditioning (conditioned anxiety) or because of some combination of both reactive and conditioned components. While it is possible that a treatment program aimed at a reduction of either of these anxiety components may be instrumental in ameliorating the other component, it would appear that a comprehensive treatment program would attempt to teach social skills as well as reduce conditioned anxiety.Desensitization procedures have demonstrated success in alleviating conditioned anxiety for a wide variety of clinical problems (Paul, 1969a. 1969b) and appears to be a logical choice for the conditioned component of dating anxiety. A number of outcome studies have reported some success in the use of in vivo desensitization (Rehm and Marston, 1968; Martinson and Zerface, 1970) and systematic desensitization (Stark, 1970) in reducing anxiety in date anxious subjects.The literature on treatment programs aimed at social skills training for date anxious subjects is meager. Melnick (1973) reported success in improving the appropriateness of the social behavior of subjects who had experienced a minimal dating history by the use of modeling, behavioral rehearsal and self-observation techniques.The present study was designed to test the relative effectiveness of two different types of treatment programs in alleviating interpersonal dating anxiety. The two experimental groups consisted of a systematic densensitization program which focused on the condition anxiety component and a social skills training program which focused on the reactive anxiety component.     

Stimulus intrusion on fixed-interval responding in the rat: The effects of electric shock intensity,temporal location,and response contingency

After a scalloped lever-press response pattern had developed under a fixed-interval food reinforcement schedule, a 15-sec electric shock was intruded for different groups of rats in the first, second, third, or fourth quarter of each inter-reinforcement interval. Shock intensity was systematically increased for individual rats over 70 sessions, from 0.05 to 1.6 mA. Additional between-groups comparisons involved response-dependent versus clock-dependent fixed-interval schedules, and response-dependent versus response-independent electric shock intrusion. Response rates within each fixed interval prior to, during, and following electric shock intrusion showed regular and reproducible increases and decreases under systematic application of the experimental variables. These results provide further evidence that the functions of a stimulus are determined in part by the parameters of intensity, response contingency, and temporal location with respect to reinforcement.     

Expressed vs inventoried interests as predictors of paramedical effectiveness

Two interest measures, a composite of six items which provide a direct assessment of an individual's preferences for Navy health care work and a Navy Vocational Interest Inventory (NVII) scale which assessed the degree of similarity between an individual's activity preferences and those of hospital corpsmen (HMs), were considered along with aptitude test scores as potential predictors of effectiveness among 2429 Navy enlisted personnel assigned to training for HM jobs. Effectiveness was defined as completion of HM training and remaining on the job for at least 2 years. The six-item composite and NVII HM scale scores were correlated .51 with each other and were correlated .27 and .28, respectively, with the effectiveness criterion. When these measures were added to the aptitude measure by using multiple regression procedures, the validity for predicting effectiveness was increased significantly from .36 to .42 with a cross-validity of .42 for the three-variable equation. These findings provide support for the contention that interest measures can be useful predictors of occupational success as well as occupational entry. Furthermore, since most of the interest-related attrition that was found in this study occurred during HM training, these findings suggest that job withdrawal attributable to mismatches in vocational interests may tend to occur very soon after the individual enters the occupational field.