Episodic storage and retrieval in visuo-spatial tasks: evidence of indirect retrieval

Episodic storage contends that the relevant target and irrelevant distractor features of a display are processed and then stored together within the boundaries of an episode, and are linked in this way. Accordingly, the selective and “direct” retrieval of either a stored target or distractor should result in the “indirect” and unintended retrieval of the other stimulus. In the present investigation, interest focused upon spatial tasks and the “indirect” retrieval of prime distractor processing. The novel findings obtained supported the existence of the “indirect” retrieval of prime distractor processing in visuo-spatial tasks and, to a lesser extent, of the stored prime target event, consistent with identity tasks (i.e. bi-directional episodically-based retrieval). Clearly, more is retrieved than is presented (Hintzman, D. L. (1984). MINERVA 2: A simulation model of human memory. Behavior Research Methods, Instruments, & Computers, 16, 96–101. doi:10.3758/BF03202365), as an episodic storage structure would predict.     

Episodic retrieval and feature facilitation in intertrial priming of visual search

Huang, Holcombe, and Pashler (Memory & Cognition, 32, 12-20, 2004) found that priming from repetition of different features of a target in a visual search task resulted in significant response time (RT) reductions when both target brightness and size were repeated. But when only one feature was repeated and the other changed, RTs were longer than when neither feature was repeated. From this, they argued that priming in visual search reflected episodic retrieval of memory traces, rather than facilitation of repeated features. We tested different variations of the search task introduced by Huang et al., with the aim of uncovering when priming is episodic and when feature based. We found that varying the signal strength of target against distractors had a strong effect on the priming pattern. In difficult search with low signal-to-noise ratios of target against distractors, the priming patterns were episodic. When feature contrasts between target and distractors were increased, priming of different features was independent and additive. Our results suggest that, during inefficient search,priming can be episodic but that, for more efficient search, priming from different features occurs independently. The results support two-stage (or multistage) accounts of priming in visual search.     

Episodic retrieval processes take place automatically in auditory negative priming

Episodic retrieval processes involved in negative priming have been argued to be susceptible to the proportion of attended repetition trials. The more trials with the same prime and probe response, the more beneficial should it be to retrieve the prime episode, particularly its response. Retrieval of the prime episode, however, is task-inappropriate for ignored repetition trials, leading to negative priming. Correspondingly, visual negative priming increases with the proportion of attended repetition trials. We tested whether the same is true for the auditory modality. Three attended repetition proportion groups (0–25–50%) showed the same amount of negative priming. All groups committed more prime response errors in ignored repetition than in control trials, implying that prime response retrieval took place. Thus, retrieval processes in auditory negative priming appear to be automatic and cannot be influenced as easily as in the visual domain. In Experiment 2, the proportion of ignored repetition trials was manipulated (25–50–75%) to test whether auditory negative priming can be strategically manipulated at all. Similar to the visual modality negative priming was reduced with increasing proportion of ignored repetition trials. Differences between visual and auditory short-term memory are discussed to account for the results.     

Parallel memory retrieval in dual-task situations: II. Episodic memory

Three experiments asked whether subjects could retrieve information from a 2nd stimulus while they retrieved information from a 1st stimulus. Subjects performed recognition judgments on each of 2 words that followed each other by 0, 250, and 1,000 ms (Experiment 1) or 0 and 300 ms (Experiments 2 and 3). In each experiment, reaction time to both stimuli was faster when the 2 stimuli were both targets (on the study list) or both lures (not on the study list) than when 1 was a target and the other was a lure. Each experiment found priming from the 2nd stimulus to the 1st when both stimuli were targets. Reaction time to the 1st stimulus was faster when the 2 targets came from the same memory structure at study (columns in Experiment 1; pairs in Experiment 2; sentences in Experiment 3) than when they came from different structures. This priming is inconsistent with discrete serial retrieval and consistent with parallel retrieval.     

Repetition priming in visual search: Episodic retrieval,not feature priming

Previous research has shown that when the targets of successive visual searches have features in common, response times are shorter. However, the nature of the representation underlying this priming and how priming is affected by the task remain uncertain. In four experiments, subjects searched for an odd-sized target and reported its orientation. The color of the items was irrelevant to the task. When target size was repeated from the previous trial, repetition of target color speeded the response. However, when target size was different from that in the previous trial, repetition of target color slowed responses, rather than speeding them. Our results suggest that these priming phenomena reflect the same automatic mechanism as the priming of pop-out reported by Maljkovic and Nakayama (1994). However, the crossover interaction between repetition of one feature and another rules out Maljkovic and Nakayama's (1994) theory of independent potentiation of distinct feature representations. Instead, we suggest that the priming pattern results from contact with an episodic memory representation of the previous trial.     

Similarity information versus relational information: differences in the time course of retrieval

Two experiments are reported that examine the time course of retrieval in a sentence matching procedure. Subjects learned lists of active and passive sentences and were tested with sentences in active or passive, correct or incorrect versions; for example, if "John hit Bill" was a studied sentence, "Bill hit John" would be an incorrect active test sentence. A response signal procedure was used so that accuracy could be measured as a function of time. The data show that sentences containing words from studied sentences are discriminable early in processing from sentences containing all new words, but discrimination of correct from incorrect versions of studied sentences occurs only later in processing (after 600-700 ms). These results demonstrate that different kinds of information are available at different points during the time course of retrieval and so suggest that modifications are required of models that provide only a unitary value for the amount of match between a test probe and information in memory. Early in processing, the growth of accuracy can be explained by a simple model that assumes independent contributions to total amount of match for each of the content words of a sentence, but this independent processing model cannot account for discrimination later in processing. Several, more general, memory models are examined with respect to their abilities to produce independent item information early in processing and relational information later in processing.     

Reviving inert knowledge: analogical abstraction supports relational retrieval of past events

We present five experiments and simulation studies to establish late analogical abstraction as a new psychological phenomenon: Schema abstraction from analogical examples can revive otherwise inert knowledge. We find that comparing two analogous examples of negotiations at recall time promotes retrieving analogical matches stored in memory—a notoriously elusive effect. Another innovation in this research is that we show parallel effects for real-life autobiographical memory (Experiments 1–3) and for a controlled memory set (Experiments 4 and 5). Simulation studies show that a unified model based on schema abstraction can capture backward (retrieval) effects as well as forward (transfer) effects.     

Differential age-related effects on conjunctive and relational visual short-term memory binding

An age-related associative deficit has been described in visual short-term binding memory tasks. However, separate studies have suggested that ageing disrupts relational binding (to associate distinct items or item and context) more than conjunctive binding (to integrate features within an object). The current study directly compared relational and conjunctive binding with a short-term memory task for object–colour associations in 30 young and 30 older adults. Participants studied a number of object–colour associations corresponding to their individual object span level in a relational task in which objects were associated to colour patches and a conjunctive task where colour was integrated into the object. Memory for individual items and for associations was tested with a recognition memory test. Evidence for an age-related associative deficit was observed in the relational binding task, but not in the conjunctive binding task. This differential impact of ageing on relational and conjunctive short-term binding is discussed by reference to two underlying age-related cognitive difficulties: diminished hippocampally dependent binding and attentional resources.     

Cognitive and neuropsychological underpinnings of relational and conjunctive working memory binding across age

The ability to form associations (i.e., binding) is critical for memory formation. Recent studies suggest that aging specifically affects relational binding (associating separate features) but not conjunctive binding (integrating features within an object). Possibly, this dissociation may be driven by the spatial nature of the studies so far. Alternatively, relational binding may simply require more attentional resources. We assessed relational and conjunctive binding in three age groups and we included an interfering task (i.e., an articulatory suppression task). Binding was examined in a working memory (WM) task using non-spatial features: shape and colour. Thirty-one young adults (mean age = 22.35), 30 middle-aged adults (mean age = 54.80) and 30 older adults (mean age = 70.27) performed the task. Results show an effect of type of binding and an effect of age but no interaction between type of binding and age. The interaction between type of binding and interference was significant. These results indicate that aging affects relational binding and conjunctive binding similarly. However, relational binding is more susceptible to interference than conjunctive binding, which suggests that relational binding may require more attentional resources. We suggest that a general decline in WM resources associated with frontal dysfunction underlies age-related deficits in WM binding.     

He said,she said: Episodic retrieval induces conflict adaptation in an auditory Stroop task

People respond more slowly if an irrelevant feature of a target stimulus is incompatible with the relevant feature or the correct response. Such compatibility effects are often reduced in trials following an incompatible trial, which has been taken to reflect increased cognitive control. This pattern holds only if two trials share some similarities, however, suggesting that it may be modulated by the episodic context. To look into this possibility, we had participants respond to high- or low-pitched tones by saying “high” or “low,” respectively, and ignore the simultaneously presented auditory word “high” or “low.” As expected, performance was impaired if the heard word was incompatible with the required response, and this Stroop-like effect was reduced after incompatible trials. This sequential modulation was observed, however, only if the voice in the two successive trials was the same, whereas no modulation was obtained when the speaker changed. The results suggest that sequential modulations are due to the automatic retrieval of episodic event representations that integrate stimuli, actions, and situational and task-specific control information, so that later reactivation of some elements of a given representation tends to retrieve the other elements as well.     

Brain activity during the encoding, retention, and retrieval of stimulus representations

Studies of delayed nonmatching-to-sample (DNMS) performance following lesions of the monkey cortex have revealed a critical circuit of brain regions involved in forming memories and retaining and retrieving stimulus representations. Using event-related functional magnetic resonance imaging (fMRI), we measured brain activity in 10 healthy human participants during performance of a trial-unique visual DNMS task using novel barcode stimuli. The event-related design enabled the identification of activity during the different phases of the task (encoding, retention, and retrieval). Several brain regions identified by monkey studies as being important for successful DNMS performance showed selective activity during the different phases, including the mediodorsal thalamic nucleus (encoding), ventrolateral prefrontal cortex (retention), and perirhinal cortex (retrieval). Regions showing sustained activity within trials included the ventromedial and dorsal prefrontal cortices and occipital cortex. The present study shows the utility of investigating performance on tasks derived from animal models to assist in the identification of brain regions involved in human recognition memory.     

Working with the relational unconscious: an integration of intrapsychic and relational analysis

From its inception, psychoanalysis has tended to idealize the curative value of insight while devaluing the mutative significance of the analytic relationship. This paper argues that applying the construct of the "relational unconscious" in clinical practice offers a possible resolution of this "mind-relationship" rift. From this perspective, transference and countertransference provoke a continual intersubjective/interpersonal enactment of a co-created infantile drama emanating from the internal worlds of analyst and analysand in which a vital form of parental and/or self loving is at stake. Case vignettes demonstrate how to apply the relational unconscious in clinical practice.     

Derived relational responding: a comparison of match-to-sample and the relational completion procedure

Previous research suggests that the Relational Completion Procedure may be an effective alternative procedure for studying derived relational responding. However, the parameters that make it effective, relative to traditional match-to-sample, remain to be determined. The present experiment compared the Relational Completion Procedure and match-to-sample protocols for training and testing Same and Opposite derived stimulus relations. Trials to criterion and overall pass rate (i.e., yield) in both procedures were compared across three variables: presence versus absence of a confirmatory response requirement, three versus five comparison stimuli, and top-to-bottom versus left-to-right presentation format. Findings demonstrated a facilitative effect of the confirmatory response requirement in both procedures. Training trials to criterion were nominally but not significantly lower during the nonarbitrary training phase in the Relational Completion Procedure compared to match-to-sample, and the overall yield on the arbitrary relational test was greater in the former procedure compared to the latter. The present findings support the further development of the Relational Completion Procedure as an efficient alternative procedure for establishing Same and Opposite relations with adult humans, and with potential applicability to other types of derived relations.     

Episodic memory and cortico-hippocampal interactions

There is a broad consensus that the hippocampal system plays a critical role in the encoding and retrieval of 'episodic' memories. Recent findings and computational modeling explicate the representational requirements of encoding episodic memories, and suggest that the idiosyncratic architecture of the hippocampal system and its interactions with cortical circuits are well-matched to the representational problems it must solve in order to support the episodic memory function. These findings also shed light on the nature of consolidation, identify the sorts of memories that must remain encoded in the hippocampal system for the long-term, and help delineate the semantic and episodic memory distinction.     

Episodic knowledge and implicit learning

Despite nearly 20 years of controversy, researchers are still divided over the contributions of abstract and episodic knowledge to performance on implicit learning tasks, and whether these types of knowledge exert their effects unintentionally or unconsciously. The present paper reviews the evidence taken to support the episodic account of implicit learning. Although substantial evidence suggests that episodic knowledge influences performance on implicit learning tasks, at present there are no techniques for testing whether these influences occur outside of awareness. It is argued that future research should investigate whether the retrieval of episodic knowledge in implicit learning tasks is insensitive to intentional control, rather than focus on the issue of awareness. Preliminary evidence suggesting that episodic knowledge can exert a nonintentional influence on task performance is reviewed, followed by a discussion of the status of consciousness as an explanatory construct in psychology.     

Quantitative relations between avoidance behavior and pituitary-adrenal cortical activity

The rate at which monkeys pressed a lever and avoided shocks was manipulated in several ways. Measurements were also made of their plasma levels of 17-hydroxycorticosteroids. The rate at which the animals pressed the lever and the frequency with which they received shocks were both implicated as determiners of the steroid levels.