Short-term memory and information processing in pigeons

Six pigeons were trained to asymptotic performance on a variable-delay matching-to-sample task in which the samples were sometimes line or color elements and sometimes line-color compounds. On compound-sample trials, the comparison stimuli were sometimes color elements and sometimes line-tilts. Sample type and delay (0, 1.5, and 4.5 sec) were varied within sessions, and sample duration (.4, 1.0, and 3.0 sec) was varied between sessions. Forgetting curves were steeper for line-tilt than for color. As sample duration increased, matching performance improved more for colors than for line-tilts, especially at delays greater than zero. Performance was better with element samples than with compound samples only on the line-tilt dimension at zero delay. Some predictions of a unitary trace growth and decay theory of pigeon short-term memory were not confirmed. A dual-code hypothesis was proposed to account for the data.     

Levels of processing, encoding strategies, and memory development.

In three experiments, memory for intentionally encoded words was compared with memory for encodings induced by asking semantic, phonemic, or surface questions. Subjects were second-, fourth-, and sixth-grade, and junior and senior high school students. Semantic encodings were more often recalled and recognized than were phonemic and surface (which did not differ). Intentional encodings were as likely to be recalled as semantic but were no more likely than phonemic and surface to be recognized, and this was true whether intentional learning was in anticipation of a recall test or a recognition test. Age trends occurred for recall, for intentional learning, and for induced processing which required subjects to generate word attributes. Age trends were attenuated for recognition and for induced processing which required subjects to verify whether a give attribute applied to the target word.     

Haptic information processing in direct and indirect memory tests

Summary Effects of learning can show up in a direct, i. e., an explicit, way or they can be expressed indirectly, i. e., in an implicit way. It was investigated whether motor processes underlie effects of repetition priming in haptic information exploration. In the test phase, blindfolded subjects had to handle objects in order to answer questions as fast as possible about their properties (e.g., temperature, texture, weight, or form), exploring the object with their hands. Some of the objects were old ones (presented in a study phase); others were added as new objects to the test phase. In addition, recognition judgements were required. The results demonstrated reliable effects of repetition priming in terms of reaction times to old, in comparison with new, objects for subjects who had been treated the same way in the study phase (active touch). Passive touch at encoding or studying the names or the visible objects themselves did not lead to effects of repetition priming in the test phase. On the other hand, performing adequate hand movements during the study improved recognition memory. The role of motor processes in indirect and direct tests of memory is discussed and related to research on memory of action events.     

Stimulus control of information processing in pigeon short-term memory

Six pigeons were trained initially on a delayed successive matching-to-sample task using red and green fields as sample and test stimuli. Following acquisition, each sample was followed either by a vertical line (“remember” cue), which indicated that sample memory would be tested, or by a horizontal line (“forget” cue), which indicated that sample memory would not be tested. During the experiments, sample memory on forget trials was tested occasionally. A series of five experiments revealed: (a) better retention on remember trials than on forget trials, (b) increased effectiveness of a forget cue when it followed closely sample offset, (c) more rapid forgetting over a retention interval ranging from 3 to 6 sec on forget trials than on remember trials, (d) a “cancellation” effect in which a remember cue which followed immediately the offset of a forget cue attenuated markedly the effectiveness of the forget cue, and (e) an “insulation” effect in which the effectiveness of a forget cue was reduced considerably when presented after a remember cue. It was concluded that pigeons actively process or rehearse the sample memory during the retention interval.     

Distinctiveness of processing,processing time and memory performance

The research reported here, explored the conditions where processing time can be used as a predictive measure for retention performance. The results showed that, in similar but quantitatively different tasks, both processing time and retention performance increased with increasing task difficulty. The strongly suggests that processing time can be used as an independent measure for extensiveness of processing, and as a predictor for later retention performance. This relationship, however, is restricted to the comparison of similar processing tasks that differ only in the amount of processing necessary to perform the task.It is hypothesized that longer processing times are indicative of more extensive processing, leading to the formation of more distinctive memory representations. These, in turn, cause higher retention performance because they allow better discrimination from other memory traces, and because they are retrieved more easily.Although distinctiveness of memory representations is an important variable in determining retention performance, it is not the only one. In a recall test, semantic relations between items had an effect on performance independent of distinctiveness.     

Flexibility of information processing and the memory of field-independent and field-dependent learners

This study examined memory differences between 48 field-independent and 48 field-dependent learners, and it hypothesized that rigid information processing by field-dependent learners interferes with cue efficiency during memory recall. The field-independent and field-dependent learners were presented with paired associates in which the target recall words were homographs, and accompanying associates emphasized one of the homograph's two meanings. Homograph recall occurred under three conditions: (a) same cue recall, (b) different cue recall (emphasized other meaning of homograph), and (c) free recall. This study found memory differences favoring the field-independent learner and findings consistent with the rigid information processing hypothesis of field-dependent learners.     

The influence of data-driven processing on perceptions of memory quality and intrusive symptoms in children following traumatic events

Ehlers and Clark [(2000). A cognitive model of post-traumatic stress disorder. Behaviour Research and Therapy, 38, 319-345] cognitive model of post-traumatic stress disorder (PTSD) has been relatively untested with children. Seventy-five children (7-16 years) were interviewed within 4 weeks of an injury that led to hospital treatment to examine whether peri-traumatic processing strategies (data-driven processing and fear) were associated with perceptions of memory quality and intrusive memories. Perceptions of memory quality mediated the relationship between data-driven processing and intrusive reactions but not avoidance, arousal or depressive reactions. Finally, the relationship between peri-event fear and intrusion reactions was mediated by perceptions of memory quality even after data-driven processing was controlled. The implications of these findings are discussed in the context of a cognitive developmental model of PTSD in children.     

Trauma narratives and emotional processing

The present study examined the relations between indicators of emotional processing (e.g. trauma narratives), posttraumatic stress symptoms, and psychological distress in two military samples (N = 120) exposed to significant training accidents. Trauma narratives were collected at 2-3 weeks, while outcome measures (e.g. IES-15, PTSS-10, and GHQ-30) were collected at 2-3 weeks, and 4 months after the accidents. Emotional processing was indexed by the content of positive and negative emotional expressions in the trauma narratives. The results showed that positive emotional expressions were associated with lower levels of psychological distress, whereas negative emotional expressions were linked to trauma specific symptoms and psychological distress at 2-3 weeks. Negative emotional expressions explained between 6-8% of the variance in trauma specific symptoms at 2-3 weeks, and 11% of the variance in psychological distress symptoms at 4 months after the traumatic event.     

Individual differences in learning and memory: A unitary information processing approach

Recent research in the area of individual differences in learning and memory is reviewed from a cognitive perspective. Using the two-state model of memory as a framework, individual variations in attentional, short-term store, and long-term store processes are discussed. The focus is on using individual differences to evaluate nomothetic cognitive models, as well as on using cognitive models in guiding research on individual differences. Both within-individual and between-individual differences in basic processes are examined. In so doing, the importance of strategy choice is stressed using the concept of cognitive flexibility. Several promising directions, both methodological and theoretical, are noted and the value of using specific information processing models in the study of individual differences is emphasized.     

Cognitive avoidance of intrusive memories and autobiographical memory: specificity, autonoetic consciousness, and self-perspective

Autobiographical memory (AM) specificity is impaired in depression and post-traumatic stress disorder. Previous studies emphasised the role of cognitive avoidance of intrusive memories in this impairment. This study aimed to examine the association of cognitive avoidance of intrusive memories with specificity, autonoetic consciousness, and self-perspective. A total of 38 healthy participants were given the revised Impact of Event Scale (IES-R) and an AM task designed to assess positive and negative memories regarding specificity, autonoetic consciousness (remember/know procedure), and self-perspective (field/observer procedure). Taking into account age, verbal IQ, mood, harm avoidance, and executive resources, the IES-R avoidance subscale was negatively correlated with specificity and remember responses for positive memories, and with remember and field responses for negative memories. These findings suggest that cognitive avoidance of intrusive memories is associated with a decrease of the episodic components of AM retrieval.     

错误记忆产生的认知与神经机制：信息加工视角

采用信息加工视角, 在划分不同信息来源的基础上分析编码、存储(巩固)、再激活/再巩固和提取的一系列加工过程如何导致错误记忆形成, 由此总结出错误记忆产生的三个可能原因：(1)因缺乏针对目标事物特异性细节的记忆表征而侧重于编码和提取目标和非目标事物共享的抽象记忆表征, 使被试更倾向于依赖抽象表征对缺失的目标细节进行重构, 引发错误记忆; (2)目标事物启动了对应图式, 导致与图式相关的非目标事物记忆表征得到增强, 引发错误记忆; (3)误导信息干扰了再度激活状态下目标事物的记忆表征, 妨碍其进行准确的记忆再巩固, 从而引发错误记忆。未来研究可进一步探讨目标事物特异性细节的表征区域、不同类型的图式表征促进非目标事物记忆表征的具体机制以及提取阶段的图式复现对错误记忆形成的影响等问题。     

Attachment and autobiographical memory retrieval: Event-related potential evidence from strategic information processing

This article presents two studies using event-related potentials combined with an autobiographical memory (AM) retrieval task and a lexical judge task to explore differences in AM retrieval among differently attached individuals and to further explore whether the source of these differences is the schematic information processing mode or strategic information processing mode. The effectiveness of the information processing mode is also studied. The results revealed that differences in the AM extraction of different attachment styles were due to the strategic information processing mode, while no differences were found in the schematic information processing used by individuals with different attachment styles. Further, the strategic information processing used by the securely attached group was more flexible and efficient than that used by the insecurely attached group; moreover, the strategic information processing mode used by the avoidantly attached group was more stable and consistent than that used by the anxiously attached group.     

A latent variables examination of processing speed, response inhibition, and working memory during typical development

This study addressed three related aims: (a) to replicate and extend previous work regarding the nonunitary nature of processing speed, response inhibition, and working memory during development; (b) to quantify the rate at which processing speed, response inhibition, and working memory develop and the extent to which the development of these latter abilities reflect general changes in processing speed; and (c) to evaluate whether commonly used tasks of processing speed, response inhibition, and working memory are valid and reliable when used with a developmentally diverse group. To address these aims, a latent variables approach was used to analyze data from 147 participants 6-24 years of age. Results showed that processing speed, response inhibition, and working memory were separable abilities and that the extent of this separability was stable across the age range of participants. All three constructs improved as a function of age; however, only the effect of age on working memory remained significant after processing speed was controlled. The psychometric properties of tasks used to assess the constructs were age invariant, thereby validating their use in studies of executive development.     

Age, information processing speed, and intelligence

Two parallel, but independent, literatures have grown out of observations that individual differences in information processing speed, as expressed in performance on choice reaction time (C RT) tasks, modestly correlate with individual differences in age and IQ test performance. These associations have prompted theories that individual differences in information processing speed functionally determine individual differences in performance of all cognitive skills by people of different general intellectual ability (Eysenck, 1986; Jensen, 1985) or age (Salthouse, 1982, 1985).

The experiments on which this literature has been based suffer from methodological weaknesses, such that comparisons have only been made very early in practice and have only concerned mean latencies for correct responses. An experiment compared 90 volunteers aged from 50 through 79 years who were grouped in terms of their performance on the AH 4 (Heim, 1968) IQ test. It explored the joint and independent effects of individual differences in age and in IQ test score and the effects of practice on mean latencies (C RTs) on the shapes of distributions of correct and incorrect responses and on the limiting speeds with which accurate responses can be made (speed/error trade-off functions). We suggest that a plausible explanation for the results is that individual differences in age and in general ability influence C RTs mainly because they affect the efficiency with which responses can be controlled to maximize speed while maintaining accuracy.