Right hemispheric specialization for mental imagery: A review of the evidence

An implicit assumption in the literature on functional hemispheric asymmetry is that the right hemisphere plays a special role in mental imagery. Using a definition of mental imagery as quasi-perceptual experience, we draw distinctions among visual imagery, visual recognition memory, and visuospatial abilities. We then review the research literature to evaluate the hypothesis that mental imagery is a specialized function of the right cerebral hemisphere, and find that it receives little unambiguous support. Case reports of loss of imagery are no more frequent with right than with left unilateral brain damage. Systematic studies of brain-injured patients provide some support for the hypothesis, but are also consistent with the alternative hypothesis of bilateral representation of imagery. Commissurotomized patients report dreaming and being able to form visual images. Behavioral and psychophysiological studies of non-brain-injured patients either fail to provide evidence in favor of the hypothesis or can be interpreted as compatible with the alternate hypothesis of bilateral hemispheric involvement in imagery. We conclude that there is, presently, insufficient empirical basis for considering imagery a right hemispheric function. We then discuss implications of this conclusion for future research.     

‘Random’ saccadic eye movements during verbal-linguistic and visual-imaginal tasks

Previous research has suggested that questions eliciting visual imagery are associated with lower rates of saccadic eye movements as compared to questions eliciting verbal processes. Two experiments reported here examined the roles of external visual stimulation and speech output in this effect. In both experiments, questions designed to elicit verbal-linguistic or visual-imaginal processing, and which required either syntactically complex or simple responses, were administered while eye movements were recorded by electrooculography. In experiment 1, 42 subjects responded while viewing either the interviewer's face or a gray oval on a video monitor. Imaginal questions elicited a lower rate of eye movements than did verbal questions regardless of the display on the monitor. In experiment 2, 17 subjects responded in conditions of light and darkness. Imaginal questions elicited lower rates of eye movements in both light and dark. Neither cognitive mode nor speech output requirements interacted with stimulus conditions in either experiment. The failure of visual conditions to influence the verbal-imaginal difference in eye movement rate is viewed as inconsistent with a visual interference interpretation of the relationship of eye movements to cognitive activity. Alternate interpretations are discussed.     

Categorical and schematic organization and the development of retrieval strategies

This study investigated the effects of schematic and categorical organization on young children's recall. Preschool and kindergarten children recalled either a taxonomic list or a story in one of two presentation conditions: an alternate condition, in which the material was presented, children recalled it and the procedure was repeated, or a successive condition in which the material was presented twice and children recalled it twice. Although preschool children's story recall was well organized, their list recall was poorly organized, and organization did not increase over recall trials in either presentation condition. In contrast, kindergarten children's recall of both the story and the list was well organized, and their recall was better organized on the second recall trial than on the first in both presentation conditions. These results are discussed in terms of the development of retrieval strategies during the preschool years/     

The role of comprehension in children's observational learning of a syntactic rule

This experiment tested the hypothesis that there is a relationship between children's comprehension of a syntactic form and the effectiveness of modeling in promoting imitation of that form. Nursery and kindergarten children received pretests for both comprehension and production of reversible passive sentences. Children who produced no passive sentences were classified either as high, intermediate, or low comprehenders on the basis of their comprehension test performance. Within each of these three groups, children were randomly assigned either to a modeling or to a no-modeling control condition. Children in the treatment condition heard a model use passive sentences to describe a series of pictures. As predicted, the imitation post-test scores of these children were significantly related to their comprehension pretest scores. No significant relationship between the post-test scores and the comprehension scores of control subjects was detected. Children exposed to the model in all three comprehension groups received significantly higher post-test scores than did their respective counterparts in the no-modeling condition. These results are discussed in terms of the hypothesis that language learning proceeds from comprehension to imitation to production.     

Reinforcement and punishment in a closed system

Children chose between toys freely and with various restrictive contingencies. Sometimes play with a preferred toy was contingent on play with a nonpreferred toy. Sometimes play with a nonpreferred toy was contingent on play with a preferred toy. Another toy (free toy) was always available during contingency sessions. Because toy playing occupied the entire session the response system was closed. When one response increased in duration others had to decrease. An analysis of closed-system responding revealed that the restrictions of the closed system together with the restrictions imposed by the contingencies forced subjects to alter the proportion of time devoted to the three responses. A geometrical model representing the closed system and an analytical method based on distance are presented to describe the data.     

Very long term memory for tacit knowledge

Very long term memory for abstract materials was examined by recalling subjects who had served in a synthetic grammar learning experiment two years earlier. In that study (Reber & Allen, 1978) we differentiated among several cognitive modes of acquisition, their resultant memorial representations, and their associated decision processes. Two years later and without any opportunity for rehearsal or relearning, subjects still retain knowledge of these grammars to a remarkable degree. Although some differences have become blurred with the passage of time, the form and structure of that knowledge and the manner in which it is put to use remain strikingly similar to the original. That is, differences traceable to acquisition mode and conditions of initial training can still be observed. As in the original study, these results are discussed within the general context of a functionalist approach to complex cognitive processes.     

Operant techniques used in stuttering therapy: A review

This article reviews research concerning the use of operant conditioning in stuttering therapy, and discusses the clinical implications of this literature. In order to be considered for this review, a report had to treat the findings of research specifically designed to use operant conditioning in the manipulation of speech disfluency. This body of experimental literature clearly indicates that operant management techniques can effectively reduce stuttering with punishment of disfluencies producing more notable results than reinforcement of fluent responses. Operant conditioning is an effective means of modifying stuttering behavior and should be more visible in terms of procedures used by speech therapists.     

Eye-fixation patterns during reading confirm theories of language comprehension

Eye-movement patterns during reading are consistent with proposition-by-proposition models of speech comprehension. (1) Fixation times are least affected by word length at ends of clauses: this confirms the theory based on the study of speech comprehension that, at such points, attention is directed inward to text integration. (2) Fixation time for words at the end of clauses is longer for canonical sequences which conform to the pattern, “N-V-N = actor-action-object”; this confirms the view that complete semantic integration of such sequences is routinely delayed until their completion. A two-variable model based on principles of exhaustive visual search and speech comprehension accounts for 80% of the fixation durations in a sample paragraph from Just and Carpenter (1980) and Thibodeou, Just ond Carpenter (1982). This comprehension-based model compares favorably with their models constructed within a production-system framework. This result clarifies the relationship between reading and listening.     

Hemiplegic writing in severe aphasia

Three patients with severe aphasia and right hemiplegia are described who could write to dictation with the right arm using a limb prosthesis though agraphic with the "intact" left hand. The phenomenon of "hemiplegic writing" is explained as an access to submerged or preprocessing levels in language and action structure, through the use of older proximal motor systems. This interpretation has implications for our understanding of language and brain function, as well as for approaches to the treatment of patients with severe language disorders.     

Interhemispheric alpha asymmetry and imagery mode

Interhemispheric alpha activity was measured while subjects were engaged in covertly imaging familiar pictorial material using three imagery modes: “shapes and colors,” “words,” or both. The results showed suppression of alpha activity in the hemisphere which is primarily involved in the cognitive mode being used by the subject.     

Enhancing the social skills of an unpopular girl: A social learning intervention

The use of a social learning approach to reduce the unpopularity of an 11-year-old girl, Rene, at a summer camp was studied. Two social skill deficiencies were suggested to be the cause of Rene's unpopularity by her bunk house counselors: her lack of contact with bunkhouse members during free choice times, and her negative, interfering conversational style. A multiple baseline design was used by the counselors to successively implement reinforcement contingencies on each class of social skill. Substantial improvements in performance were noted concurrent with the application of each contingency. These outcomes were maintained after reinforcement contingencies were withdrawn. Sociometric ratings of Rene's popularity by her bunkhouse mates improved after intervention. These outcomes are discussed from a social learning perspective.     

Evidence for differentiation of right hemisphere visual-perceptual functions

Performance on tasks sensitive to right hemisphere dysfunction (facial discrimination and perceptual closure) are reported in eight patients with right hemisphere lesions. Patients demonstrated an apparent double dissociation of performance on the two measures. Site-by-task specificity for the closure task was strongly suggested. Implications for right hemisphere organization and underlying psychological processes are considered.     

Self-esteem and reactance: Further evidence of attitudinal and motivational consequences

The present experiments were designed to explore further the relationship between self-esteem and reactance within the domains of achievement and persuasion. Previous research in the achievement context has shown that self-esteem and reactance are positively related. Experiment 1 sought to extend this relationship into the persuasion setting. As predicted, a positive self-esteem/reactance relationship was obtained. The second experiment was designed to identify a factor that might moderate the relationship between self-esteem and reactance: degree of freedom threat. Previous research in the persuasion context has shown that the aforementioned self-esteem/reactance relationship is attenuated or even reversed when freedom threat is low rather than high. Experiment 2 sought to extend this relationship into the achievement context. As predicted, the positive self-esteem/reactance relationship was considerably weakened in the low-threat environment of Experiment 2, especially in comparison to previous research in which freedom threat was considerably higher. Taken together, the present and previous studies show consistent relationships between self-esteem and reactance across achievement and persuasion domains, suggesting that the essence of reactance is similar in these two domains. Practical implications are also discussed.     

Ear asymmetry in recognition of unfamiliar voices

Female right-handed subjects were presented with a memory set consisting of five unfamiliar female voices. They were then tested with a recognition procedure in which samples of voice, memory set or novel, 2 or 4 sec in duration, were heard in one ear and a competing noise stimulus was heard in the other ear. There was an overall left-ear advantage in accuracy of recognition. This advantage held particularly for identifications of memory-set voices in the second half of trials. Internal analyses indicated that the left-ear advantage could not be attributed to greater retroactive interference during right-ear presentation. Congruent with studies of recognition of unfamiliar faces, the findings suggested right-hemisphere superiority in the recognition of unfamiliar voices.     

Transformations,basic operations and language acquisition

Errors in child speech show that some children initially formulate tense-hopping and subject-auxiliary inversion as copying without deletion. Other errors suggest that some children may formulate other movement rules as deletion without copying. A claim about the nature of the language acquisition device is made on the basis of our analysis of these errors: the language acquisition device formulates hypotheses about transformations in terms of basic operations. The basic-operations hypothesis predicts that for any transformation which is composed of more than one basic operation, there exists a class of errors in child speech correctly analyzed as failure to apply one (or more) of the operations specified in the adult formulation of the rule.     

Spontaneous translation and language mixing in a polyglot aphasic

The literature on language mixing in polyglot aphasics is reviewed and a case report of a patient with spontaneous translation is presented. A microgenetic model of language processing provides an interpretive framework for language mixing and spontaneous translation as symptoms of polyglot aphasia. It is suggested that language mixing reflects a deficit at the linguistic level while spontaneous translation reflects a deficit at the prelinguistic level of language processing. A hypothesis about the organization of multiple languages in a single speaker is proposed.     

The impact of career exploration and interview readiness on interview performance and outcomes

In a longitudinal study of 78 graduate business students, three aspects of career exploration—environment exploration, self-exploration, and the amount of information acquired—were examined as predictors of interview performance (interview rating and self-rating) and outcomes (call-back interviews and job offers). Environment exploration and the amount of information acquired related significantly with the recruiter's rating of interview performance and interview outcomes; self-exploration correlated with the recruiter's rating of interview performance. Interview readiness variables (perceived past performance, verbal persuasion, and feelings of self-efficacy) correlated modestly with career exploration variables, interview performance ratings, and interview outcomes.     

Relationships between job evaluation ratings and self-ratings of job characteristics

Self-ratings by 308 shop workers of their job variety, autonomy, task identity, and skill challenge correlate significantly with ratings by observers of the jobs' skill requirements. Self-ratings, however, are unrelated to observers' estimates of the physical demands of the jobs or to environmental conditions of the work. The self-ratings and observer measures provide complementary, not substitute, information. Self-ratings can signal person-job dysfunctions, and more objective job measures can identify possible sources of the dysfunctions. Modifications to job characteristics measures are discussed and suggestions are made to begin a new phase of programmatic job characteristics research.