Memory dysfunction in mild aphasics

The effect of mild aphasia ( n = 9), as a result of subarachnoid haemorrhage (SAH), was evaluated against one matched (sex, age, and education) control group suffering from SAH of unknown origin without aphasia, and against one matched healthy control group. According to aphasia testing (Reinvang & Engvik, 1980), criteria for a classical diagnosis were not met. Therefore, the patients were characterized as mild aphasics: They generally displayed intact audo-verbal comprehension and repetition abilities, and they demonstrated a fluent, spontaneous speech. However, they showed phonemic and semantic paraphasias, with self-corrections; a few patients displayed alexia and agraphia. Memory performance of these three groups was evaluated by a neuropsychological test battery, designed to tap various components of verbal memory function. From the results it was concluded that: (a) Short-term memory is impaired, as regards the phonological loop and the central executive in working memory, whereas maintenance rehearsal is unaffected, given that the demands on phonological coding is minimized, (b) long-term memory is also generally impaired, whereas long-term learning and forgetting by means of subject-performed tasks proceeds within a normal range. Impairments were hypothesized to reflect less efficient central executive functions of working memory, involving generation of less appropriate semantic codes and phonological representations, (c) mildy aphasic patients are not subjectively aware of their own memory deficits, and (d) aphasia classification by means of standard procedures do not sufficiently characterize the nature of a mildy aphasic patient's memory problems.     

字符的知觉表征及其启动

实验以英文单词,汉字和图片为材料,采用速示补笔测验测量了大脑左右半球的启动效应。结果是,如果学习与测验的字体和大小不变,则视觉启动右半球高于左半球。其他材料不产生这种效应。这表明,至少有一个分离的系统对构成启动的汉字的视觉表征进行编码,此系统在右半球表征形状特异形状特异信息更有效;对字符抽象特征的表征,两半球无显著差异,速示补笔测量的是前语义水平的知觉表征,是一种知觉（数据驱动）内隐记忆测验。     

卒中部位及局部脑血流量对智力的影响

用长谷川智力测定量表法测定了１８９例卒中患者的智力,分析了病变部位、脑萎缩及局部脑血流量（ｒＣＢＦ）对智力的影响．其中６９例患者长谷川分数低于２１．５分．当病变位于左半球时,属痴呆或可疑痴呆者达４２．９％;而病变位于右半球时,仅２３．１％属痴呆及可疑痴呆．ｒＣＢＦ与长谷川分数之间的相关分析显示：左额、右颞及左顶叶的ｒＣＢＦ与长谷川分数呈极显著正相关．提示左半球在智力活动中起主导作用．脑萎缩亦是影响智力的因素．     

Effectiveness of color in picture recognition memory

Investigations were conducted into the effectiveness of color in picture recognition memory. In the study phase, half of the pictures were presented in color and the other half in black and white. In the test phase, half were presented in the same color mode as the study pictures and the other half in the other mode. In immediate and 1-week-delayed tests, the recognition performance was highest when color pictures were used in both the study and test phases. The recall for the color mode of the study pictures, however, was not as good, even with the color pictures. This suggests that the effectiveness of color in picture recognition is not necessarily due to the memory for colors in the pictures themselves, but is probably due to the distinctiveness of features highlighted by the colors. We also found that in the recall performance for the color mode it was more difficult to detect the deletion of colors than to detect their addition.     

The status of the concept of intelligence

Psychometric studies have shown that “general intelligence” should be broken down into the ability to apply learned solutions to new problems (crystallized intelligence) and the ability to deal with novel intellectual problems (fluid intelligence). This distinction has been amplified upon by studies of individual differences in information processing. Crystallized intelligence depends on the problem-solving schema that people have acquired and upon their efficiency in accessing information in long-term memory. Fluid intelligence is associated with the ability to access and manage relatively large amounts of information in working memory. Measures of fluid and crystallized intelligence are important predictors of objectively measured workplace performance. Studies of actual and simulated workplaces have shown that this is largely due to differences in people's ability to manage information and the speed with which the details of a job can be grasped.     

Structure in semantic memory: A probabilistic approach using a continuous response task

In the continuous response (CR) task, the subject is given the name of a familiar category and must respond with category examples within a fixed time limit. The response sequence and the interresponse times are the measured variables. A general model is proposed for performance in the CR task. The time taken to generate a response is identified with the shortest search time from among a set of simultaneous search processes. Each response has a generation probability that is a function of the parameters governing the search process durations. Data involving the category states in the United States are used to test the model. The model accounts for the performance of nearly all individuals in these data.This article is based on a dissertation completed at the University of California-Berkeley in partial fullfillment of the requirements for the Ph.D. degree in psychology. Portions of the article were presented at the joint meeting of the Psychometric and Classification Societies (June 1984) and at the meeting of the Society for Mathematical Psychology (August 1984). The authors wish to thank Barbara Mellers, Juliet Schaffer, Steve Palmer, and Eleanor Rosch for helpful comments.     

Quantification of the effects of chlorpromazine on performance under delayed matching to sample in pigeons.

The effects of four doses of chlorpromazine (dose range 0.5 to 12.5 mg/kg) on performance under a delayed matching-to-sample procedure in pigeons was investigated, using the exponential model of memory (White, 1985). Performance was measured using a bias-free measure of discriminability, log d (Davison & Tustin, 1978), and negative exponential functions were fitted to individual-subject and group data at each dose level. A decrease in matching accuracy was found to be caused by an increase in the rate of forgetting, b, and a decrease in the initial discriminability, log d0. Changes in rate of forgetting and discriminability occurred at doses that had no statistically significant effect on response latency. The exponential model of memory accounted well for the data and provided a useful way of quantifying the effects of chlorpromazine on the processes involved in delayed matching-to-sample performance.     

The temporal–hippocampal region and retention: The role of temporo-entorhinal connections in rats

Results from previous studies suggest that the entorhinal cortex may be involved in mnemonic processes. The present study was carried out to investigate whether disruption of fibre connections between the temporal cortex and lateral entorhinal area may impair retention of a pre-operatively acquired simultaneous brightness discrimination task. The lesion resulted in a severe impairment in retaining the discrimination task (Experiment 1). The retention deficit could not be traced into the hippocampal formation by making perforant path lesions or hippocampal lesions (Experiment 2). The results indicate that the lateral entorhinal cortex is more crucial for reference memory than the hippocampal formation.     

Matching, maximizing, and the behavioral unit: concurrent reinforcement of response sequences.

Pigeons pecked two keys in a probability matching situation in which four two-peck sequences were intermittently reinforced: left-left, left-right, right-left and right-right. In Phase 1, relative reinforcement rate was varied with respect to the first response of a sequence: reinforcers were differentially assigned for left-left and left-right sequences as opposed to right-left and right-right sequences. The second response of reinforced sequences occurred equally on the left and right keys across conditions. In Phase II, relative reinforcement rate was varied for sequences that involve an alternation as opposed to those that did not. The relative outputs of the different sequences matched the relative reinforcement rates for the different sequences in both phases. Relative response rates for key pecks did not always match relative reinforcement rates. The intertrial interval separating responses was varied in both phases; increases in the intertrial interval affected the relative frequency of different sequences. The results demonstrate that response sequences acted as functional units influencing choice and thus support a structural account of choice. At the same time, the matching of relative sequence proportion and relative reinforcement rate supports a matching account.