Age-related differences in the specificity of verbal encoding

A communication paradigm was used as an analogue to cued recall to separate age-related differences in encoding and retrieval. Younger and older adults (senders) generated a series of one-word clues that would enable other subjects (receivers) to generate a designated target word. Clue and target generation tasks, analogous to the encoding and retrieval components of cued recall, were conducted in the context of either a strong or a weak associate of the target. Clues generated by older senders were less effective than clues generated by younger senders in enabling receivers to generate targets, especially when clues or targets were generated in the context of a weak associate. A deficit among older receivers was also obtained, especially when a weak-rather than a strong-associate context word was given to the receiver. Older adults experience difficulty with encoding and retrieval tasks that require processing of context-specific information that is not part of the generic information typically associated with a stimulus.     

Sex differences in clerical speed: Perceptual encoding vs. verbal encoding

Most interpretations of sex differences on clerical speed tests have emphasized the role of rapid perception of details and shifts in attention. Some have emphasized comparison and decision processes. Sex differences in speeded, successive matching were studied in four experiments with college students. The experimental task involved the successive identification of stimulus items presented in lists by tapping matching items on response cards. Sex differences were found to be related to response-card content and not to stimulus-list content. When the identification response involved tapping words, colors, or directional symbols, females were significantly faster than males; however, when the identification response involved tapping shapes, no significant sex differences were found. Results indicated that sex differences in some aspect of short-term memory may also be involved. Earlier interpretations of sex differences on speeded matching tasks in terms of such global concepts as perceptual speed are believed to be inadequate. An alternative explanation is discussed emphasizing verbal encoding, memory, and evaluation processes.     

Lateralization of temporal lobe dysfunction and verbal encoding

The contribution of encoding deficits to verbal-learning difficulties known to be associated with temporal lobe dysfunction was investigated. Auditory and visual false-recognition tasks, which assess verbal encoding strategies, were given to patients with left-temporal-lobe (LTL) and right-temporal-lobe (RTL) surgical excisions and to a group of normal controls (NC). On both auditory and visual tasks, LTL patients made significantly more false-recognition errors than the other subjects on related, but not unrelated, words in the test list. The findings indicate that LTL patients are able to initially encode verbal material and that a breakdown in information processing occurs at a later stage. On the auditory tasks, the performance of RTL patients did not differ from that of NC subjects. However, on the visual tasks, RTL patients, as compared to both LTL and NC subjects, made fewer false-recognition errors. The performance of RTL patients, in contrast to LTL patients, could be interpreted as a reduced encoding of the visual attribute of verbal material. Another possible explanation considered was difficulty in familiarity discrimination.     

Pictorial and verbal encoding in a short-term memory task

The present research attempted to manipulate the encoding modality, pictorial or verbal, of schematic faces with well-learned names by manipulating S’s expectations of the way the material was to be used. On every trial, a single name or face was presented, followed by another one; the S was asked to respond “same” if the stimuli had the same name, and “different” otherwise. The majority of second stimuli of any session was either names or faces. It was hypothesized that if S had encoded the first stimulus in the modality of the second, his judgment would be faster than if he had not appropriately encoded the first stimulus. Significantly slower reaction times were obtained to stimulus pairs where the second stimulus modality was infrequent. Further evidence that encoding of the first stimulus was in the frequent second stimulus modality comes from the finding that “different” responses were shorter when the stimuli differed on more than one attribute in the encoding (second stimulus) modality, regardless of the modality of the stimuli. Thus, evidence is presented that not only can verbal material be pictorially encoded (and vice versa), but that whether either verbal or pictorial material is verbally or pictorially encoded depends on S’s anticipation of what he is to do with the material.     

Impaired odor recognition memory in patients with hippocampal lesions

In humans, impaired recognition memory following lesions thought to be limited to the hippocampal region has been demonstrated for a wide variety of tasks. However, the importance of the human hippocampus for olfactory recognition memory has scarcely been explored. We evaluated the ability of memory-impaired patients with damage thought to be limited to the hippocampal region to recognize a list of odors. The patients were significantly impaired after a retention delay of 1 h. Olfactory sensitivity was intact. This finding is in agreement with earlier reports that rats with hippocampal lesions exhibited memory impairment on an odor delayed nonmatching to sample task (after 30 min and 1 h) and that patients with damage thought to be limited to the hippocampal region were impaired on an odor span memory task. Olfactory recognition memory, similar to recognition memory in other sensory modalities, depends on the integrity of the hippocampal region.     

Neural correlates of successful and unsuccessful verbal memory encoding

Recent neuroimaging studies suggest that episodic memory encoding involves a network of neocortical structures which may act interdependently with medial temporal lobe (mTL) structures to promote the formation of durable memories, and that activation in certain structures is modulated according to task performance. Functional magnetic resonance imaging (fMRI) was used to determine the neural structures recruited during a verbal episodic encoding task and to examine the relationship between activation during encoding and subsequent recognition memory performance across subjects. Our results show performance-correlated activation during encoding both in neocortical and medial temporal structures. Neocortical activations associated with later successful and unsuccessful recognition memory were found to differ not only in magnitude, but also in hemispheric laterality. These performance-related hemispheric effects, which have not been previously reported, may correspond to between-subject differences in encoding strategy.     

Improving the encoding of verbal reports by using MPAS: A computer-aided encoding system

The dramatically increased use of verbal report methodologies in psychological research has created a need for new tools to improve the efficiency and reliability of encoding these data. A computer-aided protocol encoding system called MPAS (Multiple Protocol Analysis System) presents individual protocol segments in a randomised order to one or more coders and then stores computer keyboard-entered codes for later output to an SPSS formatted data file. In the present paper, MPAS is described, and a brief example is provided of how MPAS can be used in a con-trolled laboratory study to rigorously analyze verbal protocol data.     

Differentiating between verbal and spatial encoding using eye-movement recordings

Visual information processing is guided by an active mechanism generating saccadic eye movements to salient stimuli. Here we investigate the specific contribution of saccades to memory encoding of verbal and spatial properties in a serial recall task. In the first experiment, participants moved their eyes freely without specific instruction. We demonstrate the existence of qualitative differences in eye-movement strategies during verbal and spatial memory encoding. While verbal memory encoding was characterized by shifting the gaze to the to-be-encoded stimuli, saccadic activity was suppressed during spatial encoding. In the second experiment, participants were required to suppress saccades by fixating centrally during encoding or to make precise saccades onto the memory items. Active suppression of saccades had no effect on memory performance, but tracking the upcoming stimuli decreased memory performance dramatically in both tasks, indicating a resource bottleneck between display-controlled saccadic control and memory encoding. We conclude that optimized encoding strategies for verbal and spatial features are underlying memory performance in serial recall, but such strategies work on an involuntary level only and do not support memory encoding when they are explicitly required by the task.     

A computer-aided digital audio recording and encoding system for improving the encoding of verbal reports

The increasing use of verbal reports in psychological research requires tools for improving the ease and reliability of collecting and coding verbal report data. An approach is described that maintains the verbal report data in digitally recorded audio form throughout the collecting and encoding processes. A new computer-aided encoding tool, CAPAS, is described, which randomly selects and plays individual protocol segments and stores computer keyboard-entered codes in an SPSS-formatted data file.     

Imagery and verbal encoding in left and right hemisphere damaged patients

Neuropsychological aspects of imaginal and verbal encoding in memory were explored in two forced-choice recognition memory experiments with patients suffering from left and right anterior cerebral hemisphere damage. In the first experiment stimulus type and rate of presentation were varied. Predictions of patient performance based on the hypothesis that left anterior hemisphere pathology impairs verbal memory coding and right anterior hemisphere pathology impairs imaginal coding were confirmed. In a second recognition memory experiment for pictures of common objects, system-specific (imaginal or verbal) interference and distractor effects were demonstrated by analyzing the effects of interpolated tasks and the nature of false-recognition errors.