Continued effects of context reinstatement in recognition

The context reinstatement effect refers to the enhanced memory performance found when the context information paired with a target item at study is re-presented at test. Here we investigated the consequences of the way that context information is processed in such a setting that gives rise to its beneficial effect on item recognition memory. Specifically, we assessed whether reinstating context in a recognition test facilitates subsequent memory for this context, beyond the facilitation conferred by presentation of the same context with a different study item. Reinstating the study context at test led to better accuracy in two-alternative forced choice recognition for target faces than did re-pairing those faces with another context encountered during the study phase. The advantage for reinstated over re-paired conditions occurred for both within-subjects (Exp. 1) and between-subjects (Exp. 2) manipulations. Critically, in a subsequent recognition test for the contexts themselves, contexts that had previously served in the reinstated condition were recognized better than contexts that had previously served in the re-paired context condition. This constitutes the first demonstration of continuous effects of context reinstatement on memory for context

The objects of visuo-spatial short term memory: perceptual organisation and change detection

We used a color change-detection paradigm where participants were required to remember colors of six equally-spaced circles. Items were superimposed on a background so as to perceptually group them either within i) an intact ring-shaped object, ii) a physically segmented but perceptually completed ring-shaped object, or iii) a corresponding background segmented into three arc-shaped objects. A non-predictive cue at the location of one of the circles was followed by the memory items, which in turn were followed by a test display containing a probe indicating the circle to be judged same/different. Reaction times for correct responses revealed a same-object advantage; correct responses were faster to probes on the same object as the cue compared to equidistant probes on a segmented object. This same-object advantage was identical for physically and perceptually completed objects, but was only evident in reaction times, and not in accuracy measures. Not only, therefore, is it important to consider object-level perceptual organisation of stimulus elements when assessing the influence of a range of factors (e.g., number and complexity of elements) in visuo-spatial short-term memory, but a more detailed picture of the structure of information in memory may be revealed by measuring speed as well as accuracy

A matter of emphasis: linguistic stress habits modulate serial recall

Models of short-term memory for sequential information rely on item-level, feature-based descriptions to account for errors in serial recall. Transposition errors within alternating similar/dissimilar letter sequences derive from interactions between overlapping features. However, in two experiments, we demonstrated that the characteristics of the sequence are what determine the fates of items, rather than the properties ascribed to the items themselves. Performance in alternating sequences is determined by the way that the sequences themselves induce particular prosodic rehearsal patterns, and not by the nature of the items per se. In a serial recall task, the shapes of the canonical “saw-tooth” serial position curves and transposition error probabilities at successive input–output distances were modulated by subvocal rehearsal strategies, despite all item-based parameters being held constant. We replicated this finding using nonalternating lists, thus demonstrating that transpositions are substantially influenced by prosodic features—such as stress—that emerge during subvocal rehearsal

Distraction in Verbal Short-Term Memory: Insights from Developmental Differences

The contribution of two mechanisms of auditory distraction in verbal serial short-term memory—interference with the serial rehearsal processes used to support short-term recall and general attentional diversion—was investigated by exploiting differences in auditory distraction in children and adults. Experiment 1 showed that serial rehearsal plays a role in children’s as well as adults’ distractibility: Auditory distraction from irrelevant speech was greater for both children and adults as the burden on rehearsal increased. This pattern was particularly pronounced in children, suggesting that underdeveloped rehearsal skill in this population may increase their distractibility. Experiment 2 showed that both groups were more susceptible to changing- than steady-state speech when the task involved serial rehearsal—indicating that both groups suffer interference-by-process—but that children, but not adults, were also susceptible to any sort of sound (steady or changing) in a task thought to be devoid of serial rehearsal. The overall pattern of results suggests that children’s increased susceptibility to auditory distraction during verbal short-term memory performance is due to a greater susceptibility to attentional diversion; in this view, under-developed rehearsal-skill increases children’s distractibility by exacerbating their under-developed attentional control rather than by increasing interference-by-process

The Maine Annex, vol. 2, no. 4

This issue of The Maine Annex covers a variety of campus events and organizations and features numerous essays and opinion pieces. Experiencing the highest enrollment among Veterans, the paper announces that the VA stipend for living costs, books, supplies, and equipment would no longer cover the cost of materials deemed by the university administration to be non-essential to the completion of specific courses of studies

The Maine Annex, vol. 2, no. 2

Maine Annex editor Roy W. Nickerson faced flack after disrupting a talk about American-Russian relations by Russian revolutionary, leader of the social-democratic Trudovik faction of the Socialist Revolutionary Party, and president of the short-lived provinsional government following the overthrow of the Czar, Dr. Alexander Kerensky. Kerensky was ousted by the Bolshevisks lead by Vladamir Lenin

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Auditory distraction and perceptual organization: Streams of unconscious processing

Perceptual organization is key to understanding auditory distraction. In order to achieve a fundamental understanding of distraction it is necessary to understand how auditory stimuli are perceived; specifically, how they are organized into entities that do not map directly onto simple single stimuli as defined by the experimenter. It is important not to mistake some arbitrary unit of analysis, such as the word, as the correct unit for understanding auditory processing; rather, the unit of the auditory object and its relative position to other auditory objects is the key to understanding distraction (as well as the whole of auditory cognition more generally). Here I provide two illustrative examples of auditory perceptual organization showing the superlative power of organizational principles: streaming by similarity and stimulus capture. I go on to show how these have been used to refine our understanding of distraction, and of the effects of distraction from sequences of sound, from single sounds, or single changes within a sequence. A common feature of work described here is that it compares the effects of different forms of organization: The nominal stimuli themselves are largely unchanged but the way they relate to each other can change distraction appreciably. That is, it is not the mere presence of sound that causes distraction but its organization and the way that relates to the currently prevailing activity

The ineluctable modality of the audible: Perceptual determinants of auditory verbal short-term memory

Classical cognitive accounts of verbal short-term memory (STM) invoke an abstract, phonological level of representation which, although it may be derived differently via different modalities, is itself amodal. Key evidence for this view is that serial recall of phonologically similar verbal items (e.g., the letter sounds b, c, g, and d) is worse than that of dissimilar items, regardless of modality of presentation. Here we show that the effect of such phonological similarity in STM can be fully accounted for by the joint action of articulatory similarity, leading to errors in speech planning processes, and acoustic similarity within auditorily presented lists, which modulates their perceptual organization. The results indicate that key evidence used to argue for the existence of abstract phonological representation can in fact be fully accounted for by reference to modality-specific perceptual and motor planning mechanisms