Effect of interpolated temporal activity on temporal short-term memory

The purpose of this research was to determine the retroactive interference effects of a single interpolated task (i.e., one temporal duration) on the retention of a criterion duration. This research is of interest because the mnemonic structure of temporal information of different durations is uncertain. Previous research has indicated that there might be a difference in structure for durations of 1 and 4 sec., although the results are inconsistent. Thus, two criterion durations of 1 and 4 sec. and five interpolated durations (i.e., 60%, 80%, 100%, 120%, and 140% of the duration of the criterion) were utilized under the method of reproduction. In addition, subjects were instructed to use either a counting strategy or none (referred to as conscious time estimation) to facilitate the retention of the temporal information. Recall was less variable when using a counting strategy than not and when estimating 1 sec. than 4 sec. However, there was no effect of interpolated activity when comparing performance across different interpolated conditions (no interpolated activity). Apparently, one interpolated duration is not sufficient to produce structural interference with a single criterion duration.     

Lateral head turning affects temporal memory

Spatial attention is a key factor in the exploration and processing of the surrounding environment, and plays a role in linking magnitudes such as space, time, and numbers. The present work evaluates whether shifting the coordinates of spatial attention through rotational head movements may affect the ability to estimate the duration of different time intervals. A computer-based implicit timing task was employed, in which participants were asked to concentrate and report verbally on colour changes of sequential stimuli displayed on a computer screen; subsequently, they were required to reproduce the temporal duration (ranging between 5 and 80 sec.) of the perceived stimuli using the computer keyboard. There was statistically significant overestimation of the 80-sec. intervals exclusively on the rightward rotation head posture, whereas head posture did not affect timing performances on shorter intervals. These findings support the hypothesis that the coordinates of spatial attention influence the ability to process time, consistent with the existence of common cortical metrics of space and time in healthy humans.     

A temporal ratio model of memory

A model of memory retrieval is described. The model embodies 4 main claims: (a) temporal memory--traces of items are represented in memory partly in terms of their temporal distance from the present; (b) scale-similarity--similar mechanisms govern retrieval from memory over many different timescales; (c) local distinctiveness--performance on a range of memory tasks is determined by interference from near psychological neighbors; and (d) interference-based forgetting--all memory loss is due to interference and not trace decay. The model is applied to data on free recall and serial recall. The account emphasizes qualitative similarity in the retrieval principles involved in memory performance at all timescales, contrary to models that emphasize distinctions between short-term and long-term memory.     

Long-term memory for temporal structure:

In three experiments, long-term memory for temporal structure was examined by having participants identify both well-known (e.g., "I've Been Working on the Railroad") and novel songs. The target songs were subjected to a number of rhythmic alterations, to assess the importance of four critical features of identification performance. The four critical features were meter, phrasing, rhythmic contour (ordinal scaling of note durations), and the ratio of successive durations. In contrast with previous work, the unaltered version of each song was identified significantly better than any altered version. This indicates that rhythm is stored in long-term memory. Furthermore, the results demonstrated that all four critical features play a role in the identification of songs. These results held for both well-known and novel tunes.     

Time perception and temporal order memory

The purpose of this research was to investigate the relation between the attentional resources underlying time perception and temporal order memory. Subjects made judgments about temporal attributes associated with a series of wordlists. Each word was displayed for 1.4 s, and the lists contained 10 words (14 s total), 15 words (21 s total), or 20 words (28 s total). Subjects judged either the list duration, the temporal order of the words, or both duration and temporal order. In addition, there were three mental workload conditions: control (no additional task requirements), and two mental arithmetic tasks (subtract 3 or subtract 7 from a series of random numbers). The results showed a pattern of bidirectional interference between timing and temporal order: the concurrent temporal order task interfered with duration judgments, and the concurrent timing task interfered with temporal order judgments. Bidirectional interference also occurred between the mental workload task and both duration judgments and temporal order judgments. The results indicate that duration and temporal order are closely related temporal attributes, and suggest that the processing of these attributes relies on a common set of executive attentional resources.     

Working memory, long-term memory, and medial temporal lobe function

Early studies of memory-impaired patients with medial temporal lobe (MTL) damage led to the view that the hippocampus and related MTL structures are involved in the formation of long-term memory and that immediate memory and working memory are independent of these structures. This traditional idea has recently been revisited. Impaired performance in patients with MTL lesions on tasks with short retention intervals, or no retention interval, and neuroimaging findings with similar tasks have been interpreted to mean that the MTL is sometimes needed for working memory and possibly even for visual perception itself. We present a reappraisal of this interpretation. Our main conclusion is that, if the material to be learned exceeds working memory capacity, if the material is difficult to rehearse, or if attention is diverted, performance depends on long-term memory even when the retention interval is brief. This fundamental notion is better captured by the terms subspan memory and supraspan memory than by the terms short-term memory and long-term memory. We propose methods for determining when performance on short-delay tasks must depend on long-term (supraspan) memory and suggest that MTL lesions impair performance only when immediate memory and working memory are insufficient to support performance. In neuroimaging studies, MTL activity during encoding is influenced by the memory load and correlates positively with long-term retention of the material that was presented. The most parsimonious and consistent interpretation of all the data is that subspan memoranda are supported by immediate memory and working memory and are independent of the MTL.     

Explaining age differences in temporal working memory

To determine the cognitive mechanisms underlying age differences in temporal working memory (WM), the authors examined the contributions of item memory, associative memory, simple order memory, and multiple item memory, using parallel versions of the delayed-matching-to-sample task. Older adults performed more poorly than younger adults on tests of temporal memory, but there were no age differences in nonassociative item memory, regardless of the amount of information to be learned. In contrast, a combination of associative and simple order memory, both of which were reduced in older adults, completely accounted for age-related declines in temporal memory. The authors conclude that 2 mechanisms may underlie age differences in temporal WM, namely, a generalized decline in associative ability and a specific difficulty with order information.     

Preserved topographical memory following right temporal lobectomy

In an attempt to study remote memory for visuospatial information, geographical knowledge was examined in patient J.N., who had received a radical right temporal lobectomy to remove a large glioblastoma. In postoperative tests J.N. displayed severe deficits in anterograde memory for visuospatial and verbal material, visuoperceptual functions, constructions, attention, and response initiation. Despite her global cognitive deficiencies she performed normally on the WAIS Information Scale and the Fargo Map Test, a measure of geographical knowledge. In contrast, patients known to have severe amnesia exhibited impairments on tests of geographical knowledge that required precise localization of features such as cities. Assuming that J.N.'s performance is typical of patients with extensive damage to the right temporal lobe, the findings suggest that the integrity of the right temporal lobe is not essential for the retrieval of premorbidly established visuospatial memories.     

The spatial or temporal organization of short-term memory

Children were shown three visually displayed digits. The digits were exposed successively in three windows in such a way, that the left-to-right order never corresponded with the temporal-sequential order. When asked to recall or recognize the digits, normal children responded in terms of temporal order. Deaf, autistic and some subnormal children, recalled or recognized the spatial, i.e. the left-to-right order. The relationship between hearing and/or speech and the temporal ordering of visual displays is discussed.     

Positional and temporal clustering in serial order memory

The well-known finding that responses in serial recall tend to be clustered around the position of the target item has bolstered positional-coding theories of serial order memory. In the present study, we show that this effect is confounded with another well-known finding—that responses in serial recall tend to also be clustered around the position of the prior recall (temporal clustering). The confound can be alleviated by conditioning each analysis on the positional accuracy of the previously recalled item. The revised analyses show that temporal clustering is much more prevalent in serial recall than is positional clustering. A simple associative chaining model with asymmetric neighboring, remote associations, and a primacy gradient can account for these effects. Using the same parameter values, the model produces reasonable serial position curves and captures the changes in item and order information across study-test trials. In contrast, a prominent positional coding model cannot account for the pattern of clustering uncovered by the new analyses.     

Influence of emotion on memory for temporal information

Contextual information, such as color and spatial location, has been found to be better remembered for emotional than for neutral items. The current study examined whether the influence of emotion extends to memory for another fundamental feature of episodic memory: temporal information. Results from a list-discrimination paradigm showed that (a) item memory was enhanced for both negative and positive pictures compared with neutral ones and was better for negative than for positive pictures and (b) temporal information was better remembered for negative than for positive and neutral pictures, whereas positive and neutral pictures did not differ from each other. These findings are discussed in relation to the processes involved in memory for temporal information.     

Adult age differences in temporal and item memory

Three experiments tested whether the relationship between age differences in temporal and item memory depends on the degree to which the item memory measure relies on memory for context. The authors predicted a stronger relationship of temporal memory to free recall than to recognition memory. Results showed that age differences in temporal memory could be eliminated after controlling for free recall but not recognition memory performance. Under some conditions recognition memory accounted for a significant portion of age-related variance in temporal memory. These results challenge past research that has interpreted age differences in temporal and item memory as independent and suggest that a generalized decline in context memory may underlie reduced performance in older adults on all types of memory tests.     

The effect of false memory on temporal perception

This study examined the effect of false memory on temporal perception. The Deese-Roediger-McDermott (DRM) paradigm, which elicits false recognition of a nonpresented word, was used to determine whether the perceived duration of falsely remembered words was longer than that for control words. The study results revealed that the perceived duration for falsely recognized words was longer than that for correctly rejected words. This is the first study to show the effect of false memory on temporal perception and suggests that temporal perception can be affected by conceptual fluency without any perceptual repetition.     

The temporal contiguity effect predicts episodic memory performance

One way to study the associative processes at work during episodic memory is to examine the order of participant responses, which reveal the strong tendency to transition between temporally contiguous or semantically proximal items on the study list. Here, we assessed the correlation between participants’ recall performance and their use of semantic and temporal associations to guide retrieval across nine delayed free recall studies. The size of the participants’ temporal contiguity effects predicted their recall performance. When interpreted in terms of two models of episodic memory, these results suggest that participants who more effectively form and retrieve associations between items that occur nearby in time perform better on episodic recall tasks. Sample code may be downloaded as a supplement for this article from http://mc.psychonomic-journals.org/content/ supplemental.     

Emotion's influence on memory for spatial and temporal context

Individuals report remembering emotional items vividly. It is debated whether this report reflects enhanced memory accuracy or a bias to believe emotional memories are vivid. We hypothesized emotion would enhance memory accuracy, improving memory for contextual details. The hallmark of episodic memory is that items are remembered in a spatial and temporal context, so we examined whether an item's valence (positive, negative) or arousal (high, low) would influence its ability to be remembered with those contextual details. Across two experiments, high-arousal items were remembered with spatial and temporal context more often than low-arousal items. Item valence did not influence memory for those details, although positive high-arousal items were recognized or recalled more often than negative items. These data suggest that emotion does not just bias participants to believe they have a vivid memory; rather, the arousal elicited by an event can benefit memory for some types of contextual details.     

Reinforcement probability modulates temporal memory selection and integration processes

We have previously shown that rats trained in a mixed-interval peak procedure (tone = 4 s, light = 12 s) respond in a scalar manner at a time in between the trained peak times when presented with the stimulus compound (Swanton & Matell, 2011). In our previous work, the two component cues were reinforced with different probabilities (short = 20%, long = 80%) to equate response rates, and we found that the compound peak time was biased toward the cue with the higher reinforcement probability. Here, we examined the influence that different reinforcement probabilities have on the temporal location and shape of the compound response function. We found that the time of peak responding shifted as a function of the relative reinforcement probability of the component cues, becoming earlier as the relative likelihood of reinforcement associated with the short cue increased. However, as the relative probabilities of the component cues grew dissimilar, the compound peak became non-scalar, suggesting that the temporal control of behavior shifted from a process of integration to one of selection. As our previous work has utilized durations and reinforcement probabilities more discrepant than those used here, these data suggest that the processes underlying the integration/selection decision for time are based on cue value.