Familiarity decisions for faces presented to the left and right cerebral hemispheres

Right-handed subjects were asked to decide whether or not faces presented briefly in the RVF or in the LVF were familiar (familiar faces were those of famous people). This task avoids the need for extensive semantic processing or temporary storage involved in conventional naming or identification tasks, and thus eliminates the contribution of such factors to any observed asymmetry. The resulting finding of faster reaction times to LVF faces, with no overall visual hemifield difference in error rates, is taken to indicate a right-hemisphere superiority either in the processes used to construct facial representations or in the accessing of face recognition units, or both.     

Oral report of words and word approximations presented to the left or right visual field

Subjects reported letter strings forming words, pronounceable high approximations to words, and unpronounceable low approximations to words presented tachistoscopically to the left or right visual field (LVF, RVF). (a) For number of strings totally correct, the same RVF superiority was obtained with high approximations as with words, the field difference with low approximations being negligible. (b) In contrast, for letter scores from partially correct strings, RVF superiority did not vary with string type. Finding (a) is interpreted to indicate that the left hemisphere is differentially specialized for processing words as units and that requiring oral report makes pronounceable strings processable as word-like units. Finding (b) suggests that the left hemisphere is not specialized for processing subword fragments.     

Tactile perception and the right hemisphere: A masculine superiority for imagery coding

Recent research regarding hemispheric lateralization has suggested complex interactions among observed asymmetries, subject coding strategies, and sex differences in the utilization of and access to information codes. Prior to tactile perception of ambiguous figures, subjects were instructed to use either a verbal (left hemisphere) or imagery (right hemisphere) strategy. A non-instruction control group was included. Although a significant overall relationship between instructed strategy and tactile asymmetries was observed, this largely was due to males' privileged access to right-hemisphere imagery codes.     

Korsakoff amnesic syndrome: The result of simultaneous deficits in several independent processes?

Alcoholic Korsakoff patients were presented six verbal list learning tasks (two denotatively and three connotatively organized, and one high-imagery word list). Twelve recall trials and three recognition probes were obtained per list. Results indicate that for Korsakoff patients, (1) recall varied with list organization, (2) recognition memory although poor was further disrupted by proactive inhibition only on denotatively categorized lists, and (3) conceptual deficits disrupted ability to appreciate simple dichotomies in denotatively categorized lists. It is hypothesized that the joint presence of deficts in specific conceptual and semantic processes in necessary although perhaps not sufficient to produce a Korsakoff amnesia.     

Lexical knowledge in anterior and posterior aphasics

A semantic categorization task was used to assess the structure of lexical knowledge in anterior and posterior aphasics. In general responses were faster for typical category members than for atypical ones and slower for semantically related nonmembers than for unrelated ones. Both groups performed at a high level of accuracy when classifying typical category members and semantically unrelated nonmembers. Their performance diverged at the category boundary. Anterior aphasics maintained relatively high levels of accuracy when classifying atypical category members and semantically related nonmembers while posterior aphasics did not. These results point to differences in the status of lexical knowledge for anterior and posterior aphasics.     

Imagery and verbal encoding in left and right hemisphere damaged patients

Neuropsychological aspects of imaginal and verbal encoding in memory were explored in two forced-choice recognition memory experiments with patients suffering from left and right anterior cerebral hemisphere damage. In the first experiment stimulus type and rate of presentation were varied. Predictions of patient performance based on the hypothesis that left anterior hemisphere pathology impairs verbal memory coding and right anterior hemisphere pathology impairs imaginal coding were confirmed. In a second recognition memory experiment for pictures of common objects, system-specific (imaginal or verbal) interference and distractor effects were demonstrated by analyzing the effects of interpolated tasks and the nature of false-recognition errors.     

A modern assessment of the basic forms of aphasia

A brief survey of the field of aphasia is presented. Many of the facts described in the neurological classics remain valid, but the interpretation of these facts must be altered. The basic principles of aphasia are reassessed in the light of neuropsychology. Neuropsychological analysis shows sensory (acoustico-gnostic) aphasia to be based upon an impairment in phonemic hearing. Motor aphasia breaks down into afferent (kinesthetic) and efferent (kinetic) aphasia. The former is based upon an impaired kinesthetic input into the speech functions, which results in a special type of oral apraxia. Efferent (kinetic) aphasia is based upon a breakdown in the kinetic organization of speech motor acts. Nominative (amnestic) aphasia consists of a number of forms, each based on either a weakness of visual or auditory analysis or difficulty in selection between evoked memory traces. “Transcortical motor aphasia” proves to be either perseverative aphasia, i.e., aphasia in which the dynamics of plasticity are impaired, or the result of the impairment of internal speech. The basic defect underlying “conduction” aphasia is beginning to be understood as a weakened acoustico-gnostic function or difficulties in retarding sideline associations.     

Reading and listening comprehension in Broca's aphasia: Lexical versus syntactical errors

Ten agrammatic Broca's aphasics were presented with a series of four picture plates together with a spoken or written sentence stimulus. All sentence stimuli were of the structure, the + N + is/are + V + ing + the + N. The four pictures on each stimulus plate represented (a) the correct response, (b) a reversal of the stimulus sentence subject and object, (c) a change in the number of the subject of the stimulus sentence, and (d) a change in one of the major lexical items of the stimulus sentence. Subjects selected the correct picture most often. When they erred, they usually selected a subject-object reversal. Number errors were less frequent, and the patients seldom selected a change in major lexical item. This pattern occurred with both written and spoken sentences. These results were interpreted as reflecting the dependence of agrammatic Broca's aphasics on the semantic interpretation of the lexicon for decoding sentences in the face of deficits in syntactical-grammatical interpretation, irrespective of comprehension modality.     

Hemispheric asymmetries in the perception of musical intervals as a function of musical experience and family handedness background

This study examines the effect of musical experience and family handedness background on the categorization of musical intervals (two-note chords). Right-handed subjects, who were divided into four groups on the basis of musical training and presence (or absence) of left-handed family members, categorized musical intervals which were monaurally presented to left or right ear. The results, based on consistency and discreteness of categorization, showed: (1) Musicians' performance is superior to nonmusicians'; (2) musicians and nonmusicians differ significantly on their ear of preference; (3) family handedness background significantly affects ear of preference among musicians but not among nonmusicians.     

Perceptual categorization in the cerebral hemispheres

The suggestion of a functional hemispheric dissociation in performing perceptual categorization was examined in two tachistoscopic experiments with normal adults. Subjects were required to match physically identical or similar, but nonidentical, pictures of animals. The first experiment showed no hemispheric difference and indicated that both hemispheres could resort to two different types of categorization process as a function of the simultaneous or delayed mode of presentation of the stimuli. In the second experiment, the viewing conditions were manipulated so as to afford a reduced amount of stimulus energy, and a significant left-visual-field advantage was then obtained. The results are discussed with respect to models of information processing in the cerebral hemispheres, and in relation to impairments in object recognition following brain damage.     

The morphological asymmetry of the hemispheres and cerebral dominance for speech: A possible relationship

The asymmetry of the posterior Sylvian branches of the middle cerebral artery was examined on the carotid angiograms of 59 patients in whom the lateralization of speech representation was known from sodium amobarbital (Amytal) studies. The usual asymmetry of these vessels was found to be present in the group of patients with left-hemisphere speech representation but significantly reduced in patients with atypical cerebral dominance for speech. A model of the inheritance of handedness and cerebral dominance is extended to take account of these results.     

Patterns of regional cerebral blood flow during attempted reading aloud by stutterers both on and off haloperidol medication: Evidence for inadequate left frontal activation during stuttering

Two stutterers, both recent college graduates, were subjected to regional cerebral blood flow measurements while attempting to read aloud. Each one received two measurements, one of which was under the influence of haloperidol, 3 mg daily. Both subjects showed improvement on medication, allowing a stuttering versus essentially no stuttering comparisons for each subject. Both subjects showed higher Broca's area flow in the right compared to the left hemisphere, during stuttering. Both showed higher Wernicke's area flow in the left compared to the right hemisphere, however, during stuttering. During reading aloud without stuttering, however, the Brocas's area flows were reversed, now showing a left hemisphere advantage. The results were interpreted as consistent with H. M. Sussman and P. F. MacNeilage's (1975, Neuropsychologia, 13, 19–26) proposal that stutterers exhibit conventional left cerebral dominance for speech reception, but inadequate left cerebral dominance for speech production.     

The working mother: A critique of the research

This article provides a critique of the research on the working mother. Three major areas of research are reviewed: (1) the effects of maternal employment on preschoolers; (2) the working mother and school age children; and (3) working mothers, identity development, and life satisfaction. It was concluded that the research on maternal employment provided very few definitive answers regarding the effects of a mother's working on her family, children, and herself. Guidelines for conducting future research on maternal employment are presented.     

Right-hemisphere speech representation and comprehension of syntax after left cerebral injury

Comprehension of language and visuo-spatial abilities were studied in 12 surgical patients with left cerebral lesions and right-hemisphere speech representation verified by sodium amobarbital tests. When left-hemisphere symptoms preceded the acquisition of speech, impaired understanding of syntactically complex sentences was associated with an early, but not late, onset of convulsive seizures. Other behavioral measures did not show a similar effect of age at seizure onset. Sparing or loss of comprehension could not be related to any aspects of the neurological histories in cases with right-hemisphere speech acquired before the onset of left-hemisphere symptoms. Factors which may have influenced the development of right-hemisphere language comprehension are discussed.     

Monaural right-ear advantage in a target-identification task

Subjects were monaurally presented with consonant—vowel syllables to the right or left ear, with or without simultaneous noise to the other ear. The subject's task on each trial was to indicate whether or not the item presented was the target item /ba/. A right-ear advantage in reaction time was obtained: 14 msec for target items, 6 msec for nontarget items. The size of this effect was comparable in the presence vs. absence of competing noise. No consistent individual differences were found in the size of the right-ear advantage for this task, although such differences were obtained in a dichotic-perception pretest.It is argued that data of this type do not permit inferences about the use of particular ear/hemisphere neural pathways.     

The composite measure of the defense mechanism inventory

A reanalysis of previously published data suggests that the Defense Mechanism Inventory can be utilized to yield a composite measure of reaction to frustration by contrasting linearly the defenses of Turning-against-object and Projection against those of Principalization and Reversal-of-affect. Factor-analytic and correlational data support the exclusion of Turning-against-self from the composite measure. Studies of content validity are presented for the combination of the four defenses into one dimension. Patterns of interitem reliability are charted for the five defenses and the composite measure for both men and women. Internal consistency data are also presented for the standard scoring as well as for a modified method to explore the feasibility of simplifying and shortening the test-taking procedure.