Biomedical subjects

E Vakil

Publications and source records attributed to E Vakil.

17 recordsLinked to original sources

PubMed1997

Indirect influence of modality on direct memory for words and their modality: closed-head-injured and control participants.

Twenty closed-head-injured (CHI) patients and 28 control participants were tested on recall and recognition of words. In addition, memory for modality (i.e., visual vs. auditory) of word presentation was measured directly (i.e., recognition) and indirectly (i.e, by its influence on word and modality recognition). As predicted, the CHI patients were impaired relative to controls on all of the direct memory tasks; that is, word recall, word recognition, and modality judgment. However, the CHI and control groups did not differ significantly on the magnitude of the modality effect (i.e., facilitation due to correspondence of modality in learning and test). The findings are interpreted in the theoretical framework that distinguishes between item (i.e., words) and source (i.e., modality) memory and between direct and indirect measures of memory.

Adolescent↗

PubMed1997

Baseline performance and learning rate of procedural and declarative memory tasks: younger versus older adults.

Twenty-five older and 25 younger adults were compared on declarative (i.e., Rey Auditory-Verbal Learning Test and Visual Pair Associations) and procedural (i.e., Tower of Hanoi puzzle and Porteus mazes) learning tasks. A dissociation between learning rate on declarative and procedural tasks was demonstrated for the elderly participants. The younger group showed a steeper learning rate than the older group on the declarative tasks. By contrast, the learning rate of both groups on the procedural tasks did not differ consistently, whether the measure was number of errors/moves or time elapsed (with one exception in which the older group showed a steeper learning rate than the younger group). The younger group's baseline performance was better than that of the older group on all tasks employed in this study. These results reinforce the importance of distinguishing between baseline performance and the rate of learning on procedural learning tasks.

Adult↗

PubMed1997

Procedural and declarative memory processes: individuals with and without mental retardation.

Learning and retention of procedural versus declarative memory tasks were examined with 26 young adults with mild mental retardation and 27 school children matched for MA. Results revealed a similar pattern of task performance. Performance of the young adults with mild mental retardation was inferior to that of the control subjects on both types of tasks. However, learning rate and retention over time were comparable, thereby maintaining the control group's consistent advantage throughout all repeated trials. These results are consistent with previous findings for individual's with mental retardation tested on memory and problem-solving tasks. Theoretical implications of this pattern of results for individuals with mild mental retardation were discussed.

Adolescent↗

PubMed1997

The effect of level of processing on perceptual and conceptual priming: control versus closed-head-injured patients.

Twenty-four closed-head-injured (CHI) and 24 control participants studied two word lists under shallow (i.e., nonsemantic) and deep (i.e., semantic) encoding conditions. They were then tested on free recall, perceptual priming (i.e., perceptual partial word identification) and conceptual priming (i.e., category production) tasks. Previous findings have demonstrated that memory in CHI is characterized by inefficient conceptual processing of information. It was thus hypothesized that the CHI participants would perform more poorly than the control participants on the explicit and on the conceptual priming tasks. On these tasks the CHI group was expected to benefit to a lesser degree from prior deep encoding, as compared to controls. The groups were not expected to significantly differ from each other on the perceptual priming task. Prior deep encoding was not expected to improve the perceptual priming performance of either group. All findings were as predicted, with the exception that a significant effect was not found between groups for deep encoding in the conceptual priming task. The results are discussed (1) in terms of their theoretical contribution in further validating the dissociation between perceptual and conceptual priming; and (2) in terms of the contribution in differentiating between amnesic and CHI patients. Conceptual priming is preserved in amnesics but not in CHI patients.

Adult↗

PubMed1996

Effect of breakfast timing on the cognitive functions of elementary school students.

OBJECTIVE: To study the effect of breakfast timing on selected cognitive functions of elementary school students. DESIGN: A 2-week randomized control intervention trial. SETTING: Five elementary schools. SUBJECTS: The subjects comprised 569 children, 51% of them boys, aged 11 to 13 years; the children were in grades 5 through 6 (17 classes). The subjects lived in different areas and had different socioeconomic backgrounds. INTERVENTION: Each subject was tested twice, by 2 versions of the Rey Auditory-Verbal Learning Test, 2 alternative forms of the logical memory subtest of the revised Wechsler Memory Scale, and 2 versions of the Benton Visual Retention Test. On the first test, before any nutritional intervention, the subjects were asked to complete a questionnaire about their food intake on the day of testing. Two thirds of the subjects received 200 ml of 3%-fat milk and 30 g of sugared cornflakes for the next 14 days, and all the subjects were reexamined on the 15th day. MAIN OUTCOME MEASURE: Scoring on the different tests was compared with baseline scores. RESULTS: After 15 days, children who ate breakfast at school scored notably higher on most of the test modules than did children who ate breakfast at home and children who did not at breakfast. CONCLUSIONS: Our results indicate that routinely eating breakfast 2 hours prior to being tested does not improve cognitive functions in 11- to 13-year-old elementary school students, but food supplementation 30 minutes prior to taking a test notably improves scoring. We suggest further studies on the relationship between meal content, feeding time, and scholastic performance.

Adolescent↗

PubMed1996

Word recall versus reading speed: evidence of preserved priming in head-injured patients.

This study addressed a number of issues. One purpose was to test whether memory-impaired, head-injured patients show the same pattern of memory task dissociation as reported in amnesics, that is, impaired explicit and intact implicit memory performance. The second purpose of this study was to apply the distinction between the acquisition and retention aspects of memory, which has not, as yet, been investigated adequately in the study of implicit memory. The third purpose was to evaluate the contribution of intra-item and inter-item processes in implicit memory. A group of 18 head-injured (HI) patients and 18 control subjects participated in this study. Subjects read two lists of 15 words seven times: five times consecutively, once after 20 min, and after a 1-hr delay. One list was read in the same order and the other in a different order. Acquisition and retention of the information were measured explicitly (i.e., recall of words) and implicitly (i.e., priming-reading speed). The results indicated that novel information is preserved in HI as in other amnesic patient groups, only when implicit, rather than explicit, measures of memory are used. The effect of contextual manipulation (i.e., order of presentation) was interpreted to suggest similar involvement of intra-as well as inter-memory processes in implicit memory in normal and memory-impaired subjects.

Adult↗

PubMed1995

Stroop color-word task as a measure of selective attention: efficiency in closed-head-injured patients.

Deficits in attention and concentration are reported to be among the most common symptoms following head injury. Various underlying mechanisms of selective attention such as excitation, inhibition, and habituation have been isolated in recent studies. In the present study 27 control and 25 closed-head-injured (CHI) subjects were compared on four conditions based on the Stroop color-word task (neutral, habituation, Stroop, and negative priming). Cross-comparison of the different tasks enables examination of the various components of selective attention. The hypothesis that the control group's overall reading time would be faster than that of the CHI group was confirmed. Also confirmed was the hypothesis that the overall reading time pattern between task conditions would be neutral < habituation < Stroop < negative priming. The prediction that the CHI patients, due to their impaired inhibitory mechanism, would not show a slower reading time on the negative priming as compared to the Stroop condition, was confirmed as well. The theoretical and diagnostic implications of the results are discussed.

Adolescent↗

PubMed1994

A supplementary measure in the Rey AVLT for assessing incidental learning of temporal order.

Temporal order judgment is considered an important aspect of memory, both clinically and theoretically. Theories treat temporal order variously as an example of automatic process, contextual information, or source memory. However, despite its significance, temporal order is not well represented in standard memory tests or batteries. The well-known Rey AVLT (Auditory-Verbal Learning Test) was judged suitable for incorporation of a temporal order measure because it already includes several measures of learning and memory. The measure was administered to 190 healthy subjects divided into four age groups, who then were given list A in random order and asked to rewrite the words in their original order. Memory for temporal order was found to be sensitive to age and gender. Although temporal order judgment was part of incidental learning, scoring was significantly higher than could be attributed to chance. The correlation pattern between temporal order and other Rey AVLT scores suggests that temporal order is related to retention rather than to acquisition.

Adolescent↗

PubMed1994

Clinical neuropsychology and brain injury rehabilitation in Israel: a twenty-year perspective.

The development of the field of neuropsychology in Israel is primarily the result of the development of rehabilitation services for traumatic brain-injured patients. The responsibility to care for and help disabled veterans has always been an important motivation for the establishment of rehabilitation services. Israel is probably one of the first countries in the world to develop community-based services specifically designed to address the needs of young patients with severe traumatic brain injury. The fairly extensive therapeutic and community services available today for both military and civilian brain-injured persons in Israel ae the result of initiatives and funding by the Israel Ministry of Defense's Department of Rehabilitation. There are two principles that characterize most of the programs in Israel: (1) multidimensional remedial intervention and (2) life-time commitment to provide support. The accessibility of patients in a small country enables professionals to conduct follow-up studies in order to evaluate the long-term effects of brain injury. Current developments in neuropsychology are in three directions. First, formal training programs in neuropsychology are being set up. Second, the involvement of neuropsychologists is being extended beyond the treatment of young patients suffering from traumatic brain injury to include the treatment of different brain pathologies in children and the elderly. Third, sophisticated neuroimaging techniques are being applied to studies in cognitive neuropsychology.

Brain Injuries↗

PubMed1994

Head-injured patients and control group: implicit versus explicit measures of frequency of occurrence.

This study was conducted in order to investigate the possibility that effortful processes are involved in the retrieval stage of the putative automatic task-frequency judgment. Head-injured (HI) and control groups were tested on a frequency of occurrence task under explicit-intentional retrieval (i.e., frequency estimation) and implicit-unintentional retrieval (i.e., word-stem priming) conditions. Subjects were presented with a list of nouns that appeared once, three times, and six times. Following presentation, subjects were first given a priming task, then a recall task, and finally a frequency judgment task. Although the control group performed better than the HI group on recall and frequency judgment tasks, the groups did not differ on the priming task. The results are discussed in terms of the relationship between effortful and automatic memory processes.

Adolescent↗

PubMed1993

Rey Auditory-Verbal Learning Test: structure analysis.

One of the major advantages of the Rey Auditory-Verbal Learning Test (AVLT) is its multiple measures of learning and memory. This study evaluated empirically whether the different scores are, in fact, not merely different expressions of a single factor, but, rather, measures of different memory domains. The Rey AVLT was administered to 146 normal subjects. Factor analyses produced one, two, or three factors depending on the combination of scores included in the analysis and on the criteria used to determine the number of factors. The basic factors identified were acquisition and retention. The latter can be subdivided further into storage and retrieval, thus yielding a total of three factors.

Adult↗

PubMed1992

Differential effect of right and left hemispheric lesions on two memory tasks: free recall of items and recall of spatial location.

The effect of lateralized cerebral damage on free recall of items and recall of spatial location, under intentional and incidental learning conditions, was investigated. Eleven right brain-damaged (RBD) patients, 10 left brain-damaged (LBD) patients, 14 young and 11 elderly normal controls, participated in this study. The overall performance of the control groups was better than that of the patient groups. For all groups, free recall was better under intentional than under incidental learning condition. On recall of spatial location the learning condition had a differential effect on the groups. The RBD group performed better than the LBD group under intentional learning condition, while the reverse was found under incidental learning condition. The young-control group showed an advantage over the elderly-control group under intentional but not under incidental learning condition. The results are discussed in regard to different approaches to the distinction between automatic and effortful memory processes and their lateralization in the cerebral hemispheres.

Adult↗

PubMed1992

Relative importance of informational units and their role in long-term recall by closed-head-injured patients and control groups.

The purpose of this study was to apply qualitative analysis to the information recalled by control Ss and closed-head-injured (CHI) patients. The Logical Memory subtest of the Wechsler Memory Scale (Wechsler, 1945) was administered to 40 CHI and 40 control Ss. Recall was tested immediately after administration, 40 min later, and 24 hr later. The analysis took into account the importance of recalled information as determined by a prior rating according to 3 levels of importance. Results suggest that CHI patients have difficulty selectively retrieving the most important information after a long delay.

Adolescent↗

PubMed1991

Differential effect of right and left hemispheric lesions on two memory tasks: free recall and frequency judgement.

We investigated the relationship between lateralized cerebral damage and two memory tasks; free recall and frequency judgement. Free recall is considered to be processed effortfully while frequency judgement is considered to be processed automatically (Hasher and Zacks). Nine right brain-damaged patients (RBD), nine left brain-damaged patients (LBD) and nine control subjects participated in this study. It was hypothesized that RBD would show an advantage over LBD on the free-recall task, whereas LBD would show an advantage over RBD on the frequency-judgement task. In accordance with our hypothesis, free-recall was more impaired in LBD than in RBD. In the frequency-judgement task, an effect of laterality of lesion was found in high (4-6) and low (0-1) frequencies, but not in the medium (2-3) frequencies. The anticipated LBD advantage was shown in judgement of the high frequencies, but unexpectedly RBD performed better than LBD in low frequencies. The results are discussed in terms of the relationship between effortful and automatic memory processes and cerebral lateralization.

Aged↗

PubMed1991

Automatic temporal order judgment: the effect of intentionality of retrieval on closed-head-injured patients.

Closed-head-injured (CHI) and control groups were tested on a temporal order task under intentional and incidental retrieval conditions. Subjects were given five presentations of a list of nouns. In the incidental retrieval condition, subjects were told that they were to remember the words but that the order was not important. In the intentional retrieval condition, subjects were given the words in an order different from that in which they were originally presented and were asked to reorder the words to match the original order. For both conditions we compared the order in which words were recalled to the order in which they were originally presented. The results suggest that temporal order memory had more effortful characteristics in the intentional than in the incidental retrieval condition. The two groups did not differ significantly in the incidental retrieval condition. However, while the control group showed a significant improvement in the intentional retrieval condition. CHI groups performance did not significantly change. This study highlights two major points: (1) intentionality at the retrieval stage determines the effortfulness with which information is processed; (2) the more automatic the tasks, the better it is preserved following closed-head injury.

Adolescent↗

PubMed1988

Evaluating evidence for automaticity in frequency of occurrence judgments: a bias for bias?

Frequency of occurrence judgments were evaluated in young adults recovering from closed-head injuries, normal elderly, and young adult controls. Impaired performance was observed in both head-injured and elderly subjects, a result contrary to Hasher and Zacks' 1979 hypothesis that this information accumulates in memory via automatic processes which are unaffected by age, but supporting their conjecture that damage to the central nervous system would be sufficient to interfere with this function. The head-injured subject's performance on the frequency judgment task was correlated with effortful memory capacity as measured by several widely used memory tests. Whether the obtained group differences reflect differences in memory capacity or response criteria effects is discussed, and several methods of analyzing the data are compared.

Adolescent↗

PubMedDate not supplied

Behavioural psychotherapy of the frontal-lobe-injured patient in an outpatient setting.

We present two cases of outpatient behavioural psychotherapy of frontal-lobe brain-injured adults. Unlike inpatient treatment of severely frontal-injured patients in which the hospital setting acts on the patient to modify behaviour, outpatient treatment teaches the self-motivated individual to use the structure and directiveness of behavioural psychotherapy to overcome his or her neuropsychological deficits. The literature describes two types of frontal syndromes: disinhibition and adynamia. Treatment of both types of syndromes is illustrated using case presentations. The therapeutic interventions for both syndromes are designed to exaggerate the link between stimulus and response to counter impaired processing of feedback. A six-stage behavioural psychotherapy model of the frontal-injured patient is outlined.

Activities of Daily Living↗