Characteristics of recovery of drawing ability in left and right brain-damaged patients

Drawings of a "person" were obtained from 21 patients with left brain damage (LBD) and 13 patients with right brain damage (RBD) at hospital discharge and 1 month postdischarge, corresponding to 2-4 and 6-8 weeks postonset, respectively. Early LBD drawings were simplistic and often incoherent. Most were placed in the upper left quadrant of the page. RBD drawings were scattered, fragmented, and elaborately detailed. Many showed evidence of left-sided neglect. The resolution of drawing disability also differed between the two groups: LBD subjects recovered drawing abilities more rapidly and more completely than RBD subjects. These differences in drawing characteristics and in the resolution of drawing disability were discernable for experienced neuropsychologists.     

Contextual cuing and memory performance in brain-damaged amnesics and old people

In Experiment 1, groups of Korsakoff amnesics and alcoholic controls learned a list of paired-associate words in a standard testing room or in a room with distinctive contextual features. Recall was tested 48 hr later in the same or other context. This procedure was repeated in Experiment 2 with old people living in institutions or in the community, but matched for age, health, education, and socioeconomic background. The amnesic patients and institutionalized old people, relative to their comparison groups, were more impaired in recalling the lists under standard conditions and were more responsive to contextual cuing, especially when the distinctive cues were provided during original learning. The results highlight the susceptibility to interference of Korsakoff amnesics and institutionalized old people and offer further evidence that both groups are more responsive to salient contextual cues than either young people or old people living in the community.     

Impaired drawing from memory in a visual agnosic patient

A case is reported of an associative visual agnosic patient who could not draw from memory objects he could recognize, even though he could copy drawings flawlessly. His ability to generate mental visual images was found to be spared, as was his ability to operate upon mental images. These data suggest that the patient could generate mental images but could not draw from memory because he did not have access to stored knowledge about pictorial attributes of objects. A similar functional impairment can be found in some other visual agnosic patients and in patients affected by optic aphasia. The present case allows a discussion of relationships among drawing from memory, imagery, and copying procedures.     

Dissociated deficits of visuo-spatial memory in near space and navigational space: evidence from brain-damaged patients and healthy older participants

Defects confined to spatial memory can severely affect a variety of daily life activities, such as remembering the location of objects or navigating the environment, until now the skills involved have been mostly assessed with regard to the visual domain using traditional pencil and paper tests. Our aim was to test the efficacy of a recently developed psychometric instrument (Walking Corsi Test: WalCT) to assess the specific contribution of spatial memory to the complex task of retrieving route knowledge. The WalCT is a 3 × 2.5-m version of the well-known Corsi Block-tapping Test (CBT), in which patients are required to memorize (and replicate) a sequence of body displacements. We assessed the ability of left and right brain-damaged patients, as well as healthy young and senior controls, to perform both the CBT and the WalCT. Results showed differences related to age in the healthy individuals and specific functional dissociations in the brain-damaged patients. The double dissociations found in this study demonstrate the importance of having a task able to detect navigational disorders, because virtual reality tasks are often much too difficult for aged brain-damaged patients to perform.     

Dissociated deficits of visuo-spatial memory in near space and navigational space: Evidence from brain-damaged patients and healthy older participants

ABSTRACT

Defects confined to spatial memory can severely affect a variety of daily life activities, such as remembering the location of objects or navigating the environment, until now the skills involved have been mostly assessed with regard to the visual domain using traditional pencil and paper tests. Our aim was to test the efficacy of a recently developed psychometric instrument (Walking Corsi Test: WalCT) to assess the specific contribution of spatial memory to the complex task of retrieving route knowledge. The WalCT is a 3×2.5-m version of the well-known Corsi Block-tapping Test (CBT), in which patients are required to memorize (and replicate) a sequence of body displacements. We assessed the ability of left and right brain-damaged patients, as well as healthy young and senior controls, to perform both the CBT and the WalCT. Results showed differences related to age in the healthy individuals and specific functional dissociations in the brain-damaged patients. The double dissociations found in this study demonstrate the importance of having a task able to detect navigational disorders, because virtual reality tasks are often much too difficult for aged brain-damaged patients to perform.     

Cognitive processes in verbal-number production: inferences from the performance of brain-damaged subjects

This article presents a model of the cognitive processes involved in the spoken production of verbal numbers (e.g., thirteen thousand four hundred two). On the basis of single-case studies of two brain-damaged subjects with number production deficits, we argue that verbal-number production involves the generation of a syntactic frame that constitutes a plan for the production of the appropriate sequence of words. The syntactic frame specifies each to-be-retrieved word in terms of a number-lexical class (i.e., ones, teens, or tens) and a position within that class. These class/position-within-class specifications guide the retrieval of lexical representations from a production lexicon that is partitioned into functionally distinct ones, teens, and tens classes. We conclude with a brief discussion of the rationale for, and advantages of, using patterns of impaired performance as a basis for drawing inferences about normal cognition.     

Inference deficits in right brain-damaged patients

The inferential reasoning ability of right hemisphere-damaged (RHD) patients was tested by presenting pairs of sentences which were to be treated as single, integrated units. The two sentences treated together made one interpretation likely (a correct inference); one of the sentences in isolation encouraged a different interpretation (an incorrect inference). The position of the misleading sentence was systematically varied. Results showed that, in contrast to normal controls, RHD patients have more trouble answering inference questions, especially those concerning incorrect inferences, than answering questions about the factual content of the passages. Also, RHD patients made significantly more errors when the misleading information was contained in the first rather than in the second sentence; this finding indicates that these patients have difficulty revising previously acquired knowledge in light of new information. These results suggest the impairment of several components of normal discourse processing subsequent to right hemisphere brain damage.     

Cognitive representations and processes in arithmetic: inferences from the performance of brain-damaged subjects.

In this article, we present data from two brain-damaged patients with calculation impairments in support of claims about the cognitive mechanisms underlying simple arithmetic performance. We first present a model of the functional architecture of the cognitive calculation system based on previous research. We then elaborate this architecture through detailed examination of the patterns of spared and impaired performance of the two patients. From the patients' performance we make the following theoretical claims: that some arithmetic facts are stored in the form of individual fact representations (e.g., 9 x 4 = 36), whereas other facts are stored in the form of a general rule (e.g., 0 x N = 0); that arithmetic fact retrieval is mediated by abstract internal representations that are independent of the form in which problems are presented or responses are given; that arithmetic facts and calculation procedures are functionally independent; and that calculation algorithms may include special-case procedures that function to increase the speed or efficiency of problem solving. We conclude with a discussion of several more general issues relevant to the reported research.     

Story processing in right-hemisphere brain-damaged patients.

The understanding of stories requires sensitivity to structural aspects of narrative, the emotional content conveyed by the narrative, and the interaction between structural and emotional facets of the story. Right-hemisphere-damaged (RHD) and normal control subjects performed a number of different analytic tasks which probed their competence at story comprehension. Results revealed that RHD subjects perform at a level comparable to that of normal controls with stories that follow a canonical form and that they show few difficulties with structural aspects of narrative. Contrary to expectation, they are strongly influenced by the "interest" level of a story and by other factors that tap emotional sensitivity. Findings are discussed in terms of the processing and arousal mechanisms which may give rise to the observed pattern of difficulties in RHD patients.     

Sensitivity to sub-syllabic constituents in brain-damaged patients: evidence from word games

Two experiments were conducted to examine whether left- (LHD) and right-hemisphere-damaged (RHD) patients exhibit sensitivity to sub-syllabic constituents (i.e., onsets and codas) in the generation of nonwords, using a word games paradigm adapted from. Four groups of individuals (including LHD fluent and nonfluent aphasic patients, RHD patients and normal controls) were trained to add syllables to monosyllabic CVC nonwords either after the initial consonant (Experiment 1) or prior to the final consonant (Experiment 2) to create bisyllabic nonwords. Experimental stimuli consisting of CCVC or CVCC nonwords tested whether participants would preserve or split the onset and coda constituents in producing the novel bisyllabic nonwords. Results revealed that the majority of subjects demonstrated sensitivity to the sub-syllabic constituents, preserving the onsets and codas. The fluent aphasic patients exhibited a greater than normal tendency to split the onset and coda constituents; however, the small number of individuals in that group whose data met inclusion criteria limits the conclusions that may be drawn from these findings. The results are discussed in relation to theories of phonological deficits in aphasia.     

The role of visuo-spatial working memory in map learning: new findings from a map drawing paradigm

Recently, increasing attention has been devoted to the study of the role of visuo-spatial working memory (VSWM) in environmental learning and spatial navigation. The present research was aimed at investigating the role of VSWM in map learning using a map drawing paradigm. In the first study, a dual task methodology was used. Results showed that map drawing was selectively impaired by a spatial tapping task that was executed during the map learning phase, hence supporting the hypothesis that VSWM plays an essential role in learning from maps. In the second study, using a correlational methodology, it was shown that performance in simultaneous VSWM tasks, but not in sequential VSWM tasks, predicted map drawing skills. These skills “in turn” correlated with map learning abilities. Finally, in the third study, we replicated the results of the second study, by using a different map. To our knowledge, the present study is the first to find evidence that the simultaneous aspects of VSWM play a fundamental role in learning from maps.     

Exploratory study of the relations between spatial ability and drawing from memory

Test scores of 119 students, attending either a public four-year college or a technical school, were related to their proportionality and detail drawing scores on the Memory for Designs Test. In regression models, the ETS Maze Tracing, Eliot-Price Mental Rotations, and Bender-Gestalt tests were consistent predictors of proportionality scores, with the latter two tests uniquely related to these. The ETS Shapes Memory Test and the Form Board Test were the strongest predictors for detail accuracy scores. The Shapes test predicted proportionality when the CTY Visual Memory Test BB was excluded. The models then provided support for the hypothesis that drawing designs from memory, a critical skill in drawing, regardless of whether one focuses on accuracy for proportionality scores or for detail scores, is jointly related to the measures of recognition, production, and traditional spatial ability measures. This study identified multifaceted skills in drawing from memory.